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It’s time to kiss the autumnal warmth of the past few weeks across the Central U.S. goodbye, as arctic air arrives in the U.S. with a vengeance…To read the full story, click here - http://www.weatherworks.com/lifelong-learning-blog/?p=1441 © 2017 H. Michael Mogil To learn more about other high-impact weather events affecting North America, be sure to click here! 
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From Floods to Droughts (Photo Credit: WPC, US Drought Monitor, SPC, Univ of Rutgers, NWS)12/23/2017  DISCUSSION: Earlier this year during the spring months, portions of Arkansas and southern Missouri experienced record flooding. Details on this previous event can be found here. Currently, a few months later, these same places are now considered to be in a moderate to severe drought, as shown by the US drought monitor image, but possibly not for long. Current conditions show an elongated frontal boundary with a weak wave of low pressure moving northeast as the precipitation follows suit. A general 0.5 – 1 inches with up to 2+ inches of precipitation fell yesterday, December 22nd, into the overnight hours across southern Missouri and Arkansas with precipitation stretching into Louisiana as this front brought thunderstorm type activity last night. This precipitation yesterday evening shows up well when looking at the synoptic scale features that were in play alleviating some of these drought conditions.  The 850 mb map shown below, which plots heights (dam), isotherms (degrees C, dotted yellow), and dew point temperatures filled (degrees C), valid 12/23/00Z, shows southerly winds bringing warm air advection, which leads to upward vertical motion, across Arkansas and working its way into southern Missouri. Gulf of Mexico moisture is being advected into the region moistening up the atmosphere enhancing the heavy precipitation threat. Accompanied with this, favorable upper level jet dynamics are present enhancing divergence (yellow contours) in the upper levels (streamlines and isotachs in knots are also plotted) of the atmosphere as shown in the 300 mb analysis valid 12/23/00Z. This enhances the rising air in this region and the chance for precipitation.   These factors come together nicely when looking at the radar imagery from yesterday evening shown below, which illustrates a nice area of precipitation where it was expected in the drought areas based on this synoptic scale analysis.  Stay tuned for future updates here across the Mississippi Valley to see if more drought alleviation is on the way!
©2017 Forecaster Joseph DeLizio Evaluating the Lower- and Upper-level Flow over North America (credit: Thermodynamic Solutions)12/7/2017  DISCUSSION: As the present national weather pattern stands, there is quite an interesting set-up in place across the United States. One of the first thing atmospheric scientists (i.e., operational forecasters and/or broadcast meteorologists) execute when doing a given forecast is to ascertain a more concrete foundation of what is currently happening at that given time near both the top, middle, and bottom portions of the "active" atmosphere. The "active" part of the atmosphere referring to the portions of the atmosphere within which a large majority of the global weather phenomena occur within the confines of. As you can clearly see in the graphic above (courtesy of the Thermodynamic Solutions Weather Company), there are very different atmospheric flow regimes in place closer to the surface and towards the middle-to-upper portions of the atmosphere.
This is chiefly due to the fact that in the middle-to-upper part of the atmosphere, there is presently a "ridge" (or an area of high-pressure) in place over and across a good portion of Western North America which is shown on the right-hand side of the graphic attached above. To the east of any ridge can often be found a "trough" (or an upper-level region of lower pressure) which is also reflected by the "dip" or "deep left-turning curve" in the deep-blue colored flow shown on the right-hand side of graphic above as well. On the right side of any trough is where you nearly always find a higher probability of there being a greater likelihood of low-pressure formation. This is a combined result of there being stronger cyclonically-turning winds from the surface upwards on the eastern side of a trough which is much more favorable for surface-layer cyclogenesis which can then extend into the mid-levels of the atmosphere as well under the right conditions. Sure enough, very far downstream, there is a strong low-pressure system parked over part of Southeastern Canada which is helping to amplify a good portion of the ongoing lake-effect snow events downwind of Lake Erie, Lake Ontario, Lake Michigan, and Lake Superior. Thus, it is always neat to see how atmospheric science theory works out in real-life application. To learn more about other interesting weather events occurring across North America, be sure to click here! ©2017 Meteorologist Jordan Rabinowitz  DISCUSSION: As a classic Arctic air blast makes it way into portions of the North-Central and the Northeastern United States, this will set the stage for another aspect of winter weather. That particular aspect being referred to is this instance is lake-effect snow. Lake-effect snow occurs as a result of when cold, moist air travels across relatively warmer water contained within the near-surface layer of various spread across the United States (and the world for that matter). In this particular situation, the combination of the cold air and the projected wind forecast will align the larger-scale flow such that areas to the east and east-northeast of both Lake Erie and Lake Ontario will likely get hit the hardest with periods of heavy lake-effect snowfall. As shown in the graphic above, some location may end up being able to measure snow in feet (rather than in inches). Therefore, it is imperative to respect the power of Mother Nature if you are currently situated within any of these forecast areas as trying to travel while under a lake-effect snow-band is quite often a very life-threatening precedent. So, be mindful of that as you plan your travel over the next few days.
To learn more about other high-impact weather events occurring across North America, be sure to click here! ©2017 Meteorologist Jordan Rabinowitz Huge Amounts of Precipitation Blanket the Northeast (Credit: Meteorologist David Tedesco)10/30/2017  Photo credit from iweathernet.com DISCUSSION: For those living in the Northeast, this past weekend has been a soaker. A low pressure system moved up the coast dropping insane amounts of precipitation (mostly rain, but higher elevations even saw snow!) The above map details how much liquid-equivalent precipitation was recorded in the past 48 hours. Areas in orange received around an inch (2.54 cm), while whole states like Delaware, New Jersey, Connecticut, and Rhode Island were blanketed by over 2 inches (5.08 cm) of rain! The central parts of New York and Pennsylvania have seen the worst of the storm, getting almost 4 inches (10.16 cm) of rain! The storm underwent bombogenesis, a term used by meteorologists to describe a rapidly intensifying storm, bringing high winds and precipitation. Millions of people in the Northeast are without power, where some areas experiences flooding, mudslides, and of course, transit problems. Approximately 5 years ago, Superstorm Sandy made landfall in the Northeast, bringing colossal destruction to the area. Some may say this storm was the ghost of Sandy. For more severe weather impacts around North America, be sure to click here! © 2017 Meteorologist David Tedesco  DISCUSSION: It has been fall on the calendar in South Florida for almost 4 weeks, but if you went outside you would not notice it. In fact, when September 22 rolls around I don’t refer to as the first day of fall, but as the first day of “Summer Extension”. So, when does fall really arrive in South Florida? Well, it all depends on your definition. I normally define it as the first day in which the morning low temperature falls below 70 degrees. That usually occurs sometime in mid-October. On the local TV station, they were defining the first day of fall as when the first cold front comes completely through the South Florida area bringing in noticeably cooler and/or drier air. With their definition, that event occurred on October 20 in 2016, October 6 in 2015, and October 22 in 2014.
However you want to define it, I for one cannot wait until that day occurs. Here in South Florida, the joke that floats around is what is the difference between fall up North and fall in South Florida? Up North it is fall when the leaves change colors, in South Florida it is fall when the license plate change colors. © 2017 Meteorologist Michael Leiba   DISCUSSION: On October 19th, the National Oceanic and Atmospheric Administration released their winter weather outlook for the 2017/2018 winter weather season.
The biggest “wildcard” of these winter weather predictions is a possible La Niña forming for the second year in a row, with a 55% - 65% chance of it setting in before the winter season begins. You may be familiar with the term “El Niño,” which is the opposite of a La Niña. Both are part of the El Niño-Southern Oscillation(ENSO). The ENSO is a naturally occurring phenomenon which results in above or below normal sea surface temperatures, and also varying wet and dry conditions over the course of a few years. La Niña, translating to “the girl” in English, occurs when the water around the equator in the eastern Pacific Ocean is cooler than normal for a number of months. When this happens, the easterly winds along the equator increase. This could be a factor as a result from this past intense hurricane season we just endured. A La Niña typically results in altered weather patterns making the southern half of the United States warmer and drier, with the Northern half of the United Stated seeing cooler and wetter winters. There are other factors to consider when forecasting the winter weather outlook, such as other oscillations in the atmosphere, including the Arctic Oscillation, which can predict how far cold air can be pushed south, and the Madden-Julian Oscillation, which can have an impact on the number of heavy rain events the west coast experiences. For December through February, NOAA predicts that wetter than average conditions will be favored across the northern part of the United States, from the Northern Rockies to the eastern Great Lakes. For the southern part of the United States, drier than normal conditions are expected to dominate. In terms of temperature, warmer than normal conditions are expected across the southern two-thirds of the country, with parts in eastern Texas/ New Mexico expected to have 50% warmer than normal temperatures. The Northern tip of the country, from Minnesota to the Pacific Northwest are expected to have cooler than normal temperatures. The rest of the country will have an equal chance of above or below normal precipitation and temperatures. As of right now, NOAA has issued a La Niña watch, meaning conditions through observations and forecast models show those cool temperatures in the eastern Pacific Ocean. Look out for the next update from NOAA on a possible La Niña expected to come out November 9th. To learn more about North American weather impacts, click here! ©2017 Meteorologist Claudia Pukropski  Margerie Glacier is 21 miles long, 250 feet high and extends 100 feet below sea level. This glacier advances approximately 30 feet per year. The ice in the front is about 75 to 200 years old. Margerie Glacier is one of eight tidewater glaciers in Glacier Bay, Alaska. A tidewater glacier is a valley glacier that flows all the way down to the ocean. Emmanuel de Margerie, a French geologist and geographer, visited the bay in 1913 naming the glacier Margerie. Small bits of ice tend to break off from the glacier known as calving. These glaciers can only be accessed by boat and plane. The image above was taken aboard a cruise ship and we were close enough to hear the thundering sound of ice breaking off from the glacier. The glacier begins on the south slope of Mount Root and flows into the Tarr Inlet. Glacier Bay National Park and Preserve is a protected area of about 3.3 million acres which are a part of a 25-million-acre World Heritage Site. This bay did not exist in 1794 when Captain Vancouver passed by as it was still ice. At the time of the image, seals were present on the ice in the John Hopkins Inlet, which means vessel traffic is prohibited.
Even though eight glaciers are advancing, nearly 95% of all glaciers are receding. For more interesting facts about North America, click here! ⓒ 2017 Meteorologist Brandie Cantrell  Image Courtesy: GOES-NOAA DISCUSSION: A pattern change is on the way this week after experiencing warmer than average temperatures coupled with windier conditions making containment for fires in Northern California difficult. This change will be apparent in the latter part of the week as several factors come together bringing cooler temperatures and some precipitation to the forecast. Wednesday evening will be the start of this pattern change as a cold front drops from the Pacific Northwest. This frontal boundary will bring cooler temperatures to the region and will push precipitation into the area. With some onshore flow, likely precipitation and snow in higher elevations should be evident. Chances for rain increase Wednesday night into Thursday and Friday. Models are indicating amounts ranging from a tenth of an inch to quarter of an inch in much needed areas affected by the Pocket, Tubbs, Nuns, Patrick, and Atlas fires. For areas south of San Francisco, light rain is expected, virga is also being seen on the radar as of early Wednesday. Onshore flow will bring stratus and increase cloudiness throughout Thursday. By Friday warming is expected to reappear in addition to dry conditions as a ridge makes its way into the area. For more localized forecasts and changes visit the Global Weather and Climate Center! © Meteorologist Jessica Olsen  DISCUSSION: As of tonight, the worst impacts from what was previously Hurricane Nate, then Tropical Storm Nate, and now Tropical Depression Nate is being felt across parts of the Ohio Valley and the Mid-Atlantic region. As a result, some additional flooding concerns are being realized for a brief time across states such as Kentucky, Tennessee, and West Virginia. This is a direct result of heavier showers persisting across these states as well as some surrounding areas as the tropical moisture associated with the weakening remnant circulation tied to Nate gradually propagates through these regions. Hence, even at this hour, there still remain to be a few flood warnings in effect across parts of Virginia in light of some heavier embedded showers moving through. Hence, even well-beyond 24 hours after the time of landfall along the central U.S. Gulf Coast, Tropical Depression Nate is still proving to be a flooding threat for millions of people in the path of this weakening tropical low pressure system.
To learn more about other high-impact weather events occurring across North America, be sure to click here! ©2017 Meteorologist Jordan Rabinowitz A Weak Nate Expected To Get More Concerning Soon (credit: Meteorologist Jordan Rabinowitz)10/5/2017  DISCUSSION: As of this earlier this evening, Tropical Storm Nate continues to be very disorganized with a substantial amount of convection on the far east side of the circulation. Having said that, the forecast track will most likely have the center of Nate moving north-northwestward with time. This track will bring the center of Nate over the far western Caribbean Sea and then over far eastern sections of the Yucatan Peninsula. After that time, the best future forecast track consensus suggests that Nate will emerge over the central Gulf of Mexico. By that point in time, Nate will be traversing over very warm ocean water across the central Gulf of Mexico by way of the Loop Current. The Loop Current is an oscillating current of particularly warm water in the upper-most part of the central Gulf of Mexico which often allows tropical cyclones (TC) to intensify (give all other factors are conducive for TC intensification) and sometimes rapidly intensify.
After a day or two moving northward across the Gulf of Mexico, the forecast track of Tropical Storm Nate (and possibly at that time Hurricane Nate) will bring this tropical storm towards the central U.S. Gulf Coast which will more than likely induce additional coastal/inland flooding concerns. Therefore, for that reason, many coastal evacuation orders have already been given out ahead of the approach of what may ultimately be Hurricane Nate. To learn more about other high-impact weather events across North America, be sure to click here! ©2017 Meteorologist Jordan Rabinowitz  Courtesy of NCEP WPC. In the top two maps, we can see how temperatures in Colorado and the general Northern Midwest are cooler than those of most of the country. The 500-mb map shows the upper level trough that enhanced lift in the state, allowing for the sustained precipitation throughout the past weekend. The precipitation map shows some 24 hour totals from Sunday for the US. Eastern Colorado received more rainfall than western Colorado. DISCUSSION: Just six days into the start of fall, Colorado is really feeling the change of the seasons. This past Thursday, Denver reached a record high of 92 degrees as one final summer hurrah. In contrast, Denver experienced highs in the low to mid 50s Saturday and Sunday, and felt some highs in the low 60s yesterday and today – a 30 to 40 degree difference in high temperatures! Along with this stark temperature change, the state of Colorado finally received some much needed precipitation, with rain falling across the state throughout the weekend. Another sign of the sudden change in seasons is the presence of snow. Elevations above 9000 feet received enough snow fall to grant the closure of the roadway to Mount Evans, and ski resorts are already preparing for the season as well.
Why the sudden change? A slow-moving cold front and upper level trough moved into the region Friday. It brought along a cold air mass that cooled Denver with temperatures that are typical of late October/early November. With plenty of moisture, and lift from the cold front, a jet streak, and the mountains, conditions were also perfect for sustained rainfall throughout the weekend. As the cold front continues to move east, conditions are expected to dry out and warm up in time for this coming weekend, with sunny skies and temperatures returning to the 70s. To learn about other high-impact weather events across North America, click here! ©2017 Katie McCracken Irma takes aim at Florida (Credit: NOAA/SSD via National Hurricane Center and NWS Key West)9/9/2017  DISCUSSION: As Hurricane Irma continues its final stretch to Florida, people are evacuating in a mass exodus from the storm. As Irma continues to crawl, it’s forecasted path continues to change as the main target has shifted west from the Miami-Palm Beach area towards Naples and the west side of the state. Many more cities including Tampa, Orlando and Daytona Beach are preparing for the storm. As time ticks closer and closer to the arrival, the escape routes have become much more limited and crowded as airports have closed or will close. In addition to the roads being crowded, many stores shelves are empty as those unable to leave grabbed the remaining supplies especially drinking water and wood to board up the doors and windows to help prevent massive damages from Irma. Irma has already impacted much of the evacuation, as Ft. Lauderdale-Hollywood and Miami airports officially closed Friday evening at approximately 9 pm. In addition, Tampa International announced they would be closing at 8 pm on Saturday due to the storm, while Orlando International announced their closure to be occurring at 5 pm on Saturday. Airports were not the only locations to announce their closures in Central Florida. Walt Disney World officially announced all the parks and attractions would be closed on Sunday and Monday, meanwhile, Universal Orlando announced they would also close early on Saturday and remain closed through Sunday and Monday. On Friday night, the National Weather Service expanded a Hurricane Warning across Florida with the northern boundary being drawn from Manatee County to Indian River County and as far south as the waters surrounding the Florida Keys. The NWS has also issued Hurricane Watches for much of the rest of the Florida peninsula including Tallahassee. In addition, the NWS office in Key West issued this tweet:  To learn more about other high-impact weather events occurring across North America, be sure to click here!
©2017 Meteorologist JP Kalb  DISCUSSION: As Hurricane Irma continues its torrid pace to potentially impact Florida, many people are leaving or in the current stages of planning to leave by plane or by car before the hurricane is forecasted to reach the coast. Locals are not the only ones preparing to leave, however, tourists from central Florida destinations such as Walt Disney World, Universal Studios Florida and Kennedy Space Center are currently trying to re-adjust plans or cancel them outright.
In response to the upcoming hurricane threat, Governor Rick Scott of Florida (R) has suspended all of the tolls to help the evacuations as well as ordered all schools to be closed. Governor Scott has also in advance declared a state of emergency as among the brunt of Irma’s landfall is projected to hit in the metropolis of Miami, Ft. Lauderdale and Palm Beach. This area is forecasted to receive damage costs in the millions or even hitting billions of dollars. In addition to the roads being affected from evacuation, two of South Florida’s airports, Miami International and Ft. Lauderdale-Hollywood International will be hit hard as both are major hubs and focus cities for American Airlines as well as JetBlue, Spirit Airways, and Southwest Airlines. Both airports will likely close as the first band hits as planes there cannot operate in crosswinds greater than 35 mph as well as the tower being forced to close at 55 mph winds. Ft. Lauderdale-Hollywood Airport announced on Thursday that it would be closed starting Friday night. Many airlines have cancelled flights to both airports in preparation for the closures. Some other major areas such as the Orlando, Daytona Beach, and Jacksonville will be hit as well. In these areas, many tourists are rearranging or cancelling their plans as well as trying to evacuate as the area will be hit by the storm. Among the affected regions is the major airport of Orlando International which feeds in most of the tourists to central Florida. The airport announced on Thursday it would close on Saturday at 5 pm in preparation for the storm. The NWS is currently forecasting the winds at the airport to pick up Sunday afternoon with windspeeds near 35 mph at 4 pm which would make it impossible for planes to take off at that time. Meanwhile, Universal Studios and Walt Disney World have not made announcements of whether the parks will close but have posted links about what would happen if people chose to reschedule their trips due to the hurricanes such as cancellation policies. Also, Kennedy Space Center (KSC) had already issued a hurricane condition for employees which has prompted evacuation. NASA has also started to shore up some of the major facilities such as launch facilities, rockets, and the Vehicular Assembly Building. In addition to tourists and locals, many schools and universities will be closed due to the storm including the University of Miami, Embry-Riddle Aeronautic University, University of Central Florida as well as smaller community colleges. Dr. Shawn Milrad, professor of Meteorology at Embry-Riddle, described the Embry-Riddle campus as a ghost town as all the entire campus was closed and the dorms are currently being used for shelters. Milrad also said, “The students at Embry-Riddle especially the meteorology ones are worried especially those from South Florida.” Milrad also included that the meteorology department will have a weather station to track the data of Irma since the station happened to survive Hurricane Matthew the past year. In addition to classes be cancelled, several college football teams across the state are affected. Among the teams affected include the Miami Hurricanes, Florida Gators, and South Florida Bulls all had their games for the weekend cancelled, meanwhile, the Florida State Seminoles and the Central Florida Knights moved their home games to earlier times and dates respectively in anticipation of the storm. To learn more about other high-impact weather events occurring across North America, be sure to click here! ©2017 Meteorologist JP Kalb Terrifying Inferno in the West (Credit: Remote Sensing Applications Center, New York Times)9/7/2017  DISCUSSION: As the southeast United States prepares for a historic hurricane, the western half of the country has been facing their own problems. Particularly in the Pacific Northwest, wildfires have been raging for the past several days, even prompting the governor of Washington to declare a state of emergency. Logan Johnson from the National Weather Service in Seattle says quite ominously, “If you look outside, you might think it’s just clouds.” In most places the air smells of burned wood and the skies have turned a disorienting color of brownish orange. Neither Seattle, Washington nor Portland, Oregon has received any significant precipitation in at least 50 days. In a region known for rain, an unusually dry summer has provided conditions exclusive for wildfires to flourish. A strong ridge of high pressure has settled over the majority of the Pacific Northwest. This has heated the air and prevented storms from entering the area. As a result, places in northern California have experienced record-breaking heat. Trees, grass, and other foliage have dried out, meaning if one small spark occurs then the entire area can quickly be set ablaze. Although precipitation has been absent, winds are still very strong. One of the main concerns now from the fires is ash and smoke, leading to air quality alerts issued in parts of Washington, Oregon, Montana, Idaho, and California. Click here to see the locations of current wildfires in the United States. Click here to see satellite images of the wildfires. The video is taken northbound 210 Freeway in the La Tuna Canyon. This is the largest fire in Los Angeles history. To learn more about high-impact weather events occurring across North America, be sure to visit the Global Weather and Climate Center! ©2017 Meteorologist Nicholas Quaglieri  DISCUSSION: There is a big upper level ridge over the Pacific Coast which is increasing temperatures through Labor Day weekend. In addition to the increasing temperatures, the ridge is bringing smoke from fires in Northern California and Oregon into Central California including the San Francisco Bay Area and the San Joaquin Valley. The heat wave is supposed to last through the entire weekend although Sunday seems to be the start of a cooldown from the heatwave as the ridge would slowly moving out easterly. Much of the heat being brought in comes from the very warm Great Basin by the clockwise circulation of the ridge. In addition, there is subsidence (sinking air) occurring along with the planetary boundary layer (PBL) being around 850 millibars in the San Francisco Bay Area which is helping to drive up the temperatures.
On Friday, many records for the month of September across the San Francisco Bay Area was shattered including in San Francisco where the main city reached 106 degrees while San Francisco International Airport had reached a high of 104 degrees. Some of the highest temperatures in the 110s were recorded in locations away from the San Francisco Bay such as Concord. Meanwhile, in the Sacramento and San Joaquin Valleys, temperatures reached the 100s as well and threatened to climb to 110 especially in Sacramento where the high at Sacramento Executive reached a high of 109 during the day. Saturday was a continuation of the heat and daily high records. San Jose had topped up at 107 degrees at the airport while Livermore got warmer by a few degrees. However, some locations were cooler by a few degrees along the coastline but most places remained about the same. In addition to the daily high, the lows were very warm as San Jose bottomed out at 74, San Francisco in the low 70s, while Oakland and Livermore got down into the high 60s. All of which are at least 10 degrees above the normal low temperatures meanwhile the highs were between 20 and 30 degrees above the normal highs according to the climatological reports provided by the National Weather Service. The lows on Saturday were much higher than Friday as a some of the heat was trapped by smoke that was aloft as well as the low PBL and subsidence. The high temperatures and smoke were also factoring into air quality for both areas. In the San Francisco Bay Area, the Bay Area Air Quality Management District issued several consecutive days of “Spare the Air” alerts as well as determining the air quality to be unhealthy especially for sensitive groups. Meanwhile, the air quality district for the Central Valley had also measured the air quality as unhealthy for sensitive groups. To learn more about other high-impact weather events occurring across North America, be sure to click here! ©2017 Meteorologist JP Kalb  DISCUSSION: Many people that did not experience the full-force and natural fury associated with the recent U.S.-based landfalls of Hurricane Harvey never fully understood the numbers behind what was left behind in the wake of the recent devastation to a good portion of southeast Texas. Attached below is a great article (courtesy of Meteorologist Gene Norman) which excellently captures the details behind what unfolded with the recent landfalls of Hurricane and then Tropical Storm Harvey in the second of the two U.S. landfalls which occurred.
"I’ve heard that phrase repeated over and over as Hurricane Harvey unleashed historic flooding across southeast Texas and southwest Louisiana. Having lived in Houston for half my life, I am heartbroken to see the people in that great city and the region suffering. So first, I hope that after you read this, you will take a moment to help those in need: http://bit.ly/harvey_help.As a broadcast meteorologist, having assisted people get through the last major storm to hit Houston, Ike in 2008, I have some thoughts on Harvey - specifically on messaging. As in any post-storm assessment, there are things that were done very well and things that can be improved. We in the weather enterprise are a great group and we should be rightly proud of the advancements made in the science of meteorology to detect, analyze and predict threats. However, we tend to be a largely insular group that speaks a common language, but often “talks to itself”. We can quickly recite past storms based on their category, but the general public might not be making these distinctions in the same way. For example, while Harvey was technically the strongest storm to hit the U.S since the last Category 4 storm, Charley in 2004, some were confused at this comparison in the light of Matthew (2016), Sandy (2012) and Katrina (2005). For them, a hurricane’s impact has more meaning than its meteorological designation. Perhaps its time to reconsider the use of a single-number index for classifying a tropical threat and focus more on what will likely happen. If the home page of the National Hurricane Center showed the forecast for the storm along with icons illustrating people on roofs, buildings destroyed and cars floating, that might have conveyed the seriousness of this particular storm. A person in Houston, even a seasoned resident, seeing Harvey’s landfall forecast projection near Corpus Christi, 150 miles away, might not have properly understood that torrential rainfall would fall where they are. Yes, there were predictions of 15, 20 inches or more of rain that were largely consistent on Thursday and Friday. If you’ve lived in Houston, you know – it floods. In fact, you likely know the “usual suspect” flood locations. Past torrents have made traffic treacherous, even deadly and some homes may have taken on water. Few realized that Harvey’s rains were going to produce flooding practically everywhere and many could end up homeless. This despite the repeated use of the word “catastrophic” in numerous forecasts prior to the first drop falling. Compounding the issue was timing and this again points to how important it is to clearly communicate. Leading up to the storm’s arrival, the projection most often shown was of a 30+ inch total over a five-day period, from Friday to the following Wednesday. While this was largely accurate in terms of amount (even though some spots saw an astounding 50 inches), it may have been interpreted as an average of 4 to 5 inches a day for the five-day period. That’s why some many residents and even public officials indicated “surprise” when they awoke to 15 to 20 inches or more Sunday morning and a city largely drowning. Numerous posts from some within the weather enterprise expressed outrage over confusion from anyone about what occurred. We were busy high-fiving ourselves over model forecasts that seemed dead-on, information we assumed the public interpreted the same way. Yet, there was still a disconnect in messaging. Or it could have been something more basic – a simple disbelief. While “we” within the weather enterprise were convinced of the veracity of the forecast based on its consistency, those hearing this information, perhaps including those with public safety authority still might have been slightly skeptical. When I entered broadcasting some twenty-five years ago, I immediately learned an important lesson – “people don’t care how much you know until they know how much you care.” Early in my career, I wanted assure people that I knew what I was talking about. Coaches and others encouraged me to work more on connecting with viewers. Extreme messaging such as the repeated use of the phrases “catastrophic” and “parts of Texas will be uninhabitable” weren’t just hyperbole. Hopefully, lessons learned after Harvey will further move the weather enterprise in a direction that delivers messaging that doesn’t just speak to ourselves but has a greater impact to the end user." To learn more about other high-impact weather events occurring across North America, be sure to click here! ©2017 Meteorologist Jordan Rabinowitz 
DISCUSSION: As millions of people both from across the United States of America and the world have watched, Major Hurricane Harvey made landfall with a very loud bang across a good portion of southeastern Texas later Friday night. After well over 48 hours (or 2 days) of near-constant rainfall, many areas across parts of southeast Texas have now received well over 30 inches and in some cases over 40 inches of total rainfall over the course of the last couple of days. These excessive rainfall totals have been the direct result of efficient moisture transport both off the northwestern Gulf of Mexico as well as directly from the persistent circulation associated with what still now remains to be Tropical Storm Harvey. Attached below is a direct excerpt from the GOES-16 Satellite Facebook Account which more elaborately describes the evolution of this situation up to this point.
"GOES-16 infrared imagery depicts the hourly of the evolution of Harvey from August 22 through August 28, 2017. A strengthening Tropical Storm Harvey approached Texas Gulf coast on August 24, 2017. Harvey initially developed and was named on August 17 in the Atlantic just east of the Lesser Antilles. A couple of days later, Harvey weakened to a wave before crossing over the Yucatan Peninsula. After advancing into the Gulf of Mexico on August 22, Harvey strengthened again to a Tropical Storm. On August 24, Harvey was forecast to become a Major Hurricane before making landfall. Harvey continued to strengthen through August 25, and made landfall on the Texas coast as a Category 4 Hurricane around 10:00 p.m. CDT that evening. A GOES-16 1-min mesoscale sector was consistently available over Harvey during its life cycle. For tropical cyclones, 1-min imagery has proven to aid in identifying a center of circulation and in tracking thunderstorm evolution. On August 24, 30-second imagery (two overlapping 1-min sectors) was requested to track Harvey, providing a rare look at a strengthening tropical system. By the morning of August 26, Harvey had weakened to a category 1 hurricane, continuing to produce strong winds and heavy rain across a large swath of Texas. By the morning of August 28, Harvey had not moved much, still dropping heavy rainfall over southeast Texas and now western Louisiana." To learn more about other high-impact weather events occurring across North America, be sure to click here! ©2017 Meteorologist Jordan Rabinowitz  DISCUSSION: As Hurricane Harvey hits the Texas coast, not only is flooding and heavy rains a major concern on the roadways, it is also a major concern at many airports. Houston will be among the firsts as Houston-Hobby and Houston Bush Intercontinental will be affected heavily as they are the hubs for Southwest and United Airlines respectively. Also, Dallas-Ft. Worth, one of the busiest airports in the United States as well as the biggest hub for American Airlines will be affected along with Dallas-Love where Southwest has a smaller focus city operation. Smaller airports including Austin-Bergstrom will also be affected due to the operations there.
The main reason that many of these airports are going to be closed and have many flight cancellations are due to very high winds as well as thunderstorms which would make it hard for planes to land and takeoff in. These conditions also would make it unsafe for the bag handlers and those working at the gate because they could get injured or killed due to these conditions. Also, the heavy rains would make it hard for planes to brake when landing because of the slick runways and could possibly get into an accident. In addition, the winds would make it hard for planes to takeoff especially when the winds at airports with only parallel runways such as Dallas-Ft. Worth will make it impossible to takeoff safely without being blown off course or even tipped over. In addition, there is a huge risk of heavy turbulence which would make it hard for planes to fly smoothly as well as downdrafts which have been known to create accidents. Harvey is having a big effect nationwide on flights as much of the nation’s largest airlines would be without a good number of their fleets which are grounded in cities like Houston and Dallas, as well as not being able to get planes to cover some routes which are needed at other airports. To learn more about this and other high-impact weather events occurring across North America, be sure to click here! © 2017 Meteorologist JP Kalb 
DISCUSSION: As of the middle of this afternoon on this Friday (August 25th, 2017), we (i.e., hundreds of atmospheric scientists from across the nation) are continuing to carefully monitor updates on the stats and forward progress of now Major Hurricane Harvey. Between the epic rainfall on tap, the clearly strong winds associated with this powerful/incoming tropical cyclone, and the major storm surge (which is already increasing quickly in many places), this is going to without question be a very historic tropical cyclone landfall for millions of people in its path. Attached above is an afternoon briefing updating from myself (Meteorologist Jordan Rabinowitz) which details the latest on this very (and increasingly more) dangerous tropical cyclone and where things will go from here over the course of the next several hours. There will be many more updates on our Twitter feed (@gwccwx), so be sure to follow our national correspondent team there on Twitter, on Facebook, and here on our website!
To learn more about other high-impact weather events occurring across North America, be sure to click here! ©2017 Meteorologist Jordan Rabinowitz An Uncertain Future for Tropical Depression Harvey (credit: WSIL Meteorologist Nick Hausen)8/23/2017  DISCUSSION: Over the next few days, Tropical Depression Harvey is projected to continue gradually making its way towards the greater Southeast Texas region as it continues on its current north-northeastward track across the far western portions of the Gulf of Mexico. As it continues to do so, Harvey (regardless of whether it remains at tropical depression or regains tropical storm intensity) will be bringing in a plethora of rainfall as well as a prolonged period of gusty (and some potentially more damaging) winds to the surface along the immediate western Gulf Coast. However, based on the fact that there will not be much (if any) larger-scale atmospheric features nearby Harvey near the projected time frame for its first official United States landfall, there is a fairly large degree of uncertainty regarding the exact future track which Harvey will follow as it approaches and then subsequently moves inland across parts of the South-Central United States. Therefore, if you live anywhere across states including (but certainly not limited to) Texas, Louisiana, Arkansas, Oklahoma, and Missouri, it is imperative to remain vigilant in the coming days as weak tropical low pressure systems similar to this one which move slowly inland are historically known for producing historically large and high-impacting rainfall events. Be sure to stay tuned right here at the Global Weather and Climate Center for updates on this evolving situation with Tropical Depression Harvey in the coming hours and days!
To learn more about this and other high-impact weather events occurring across North America, be sure to click here! ©2017 Meteorologist Jordan Rabinowitz While ex-hurricane Franklin dissipated quickly over Mexico yesterday, a much weaker tropical system began affecting Florida (Fig. 1). On Wednesday, the system was located over the Bahamas and all its storminess remained well east of Florida. In fact, thanks to the dynamics of these “tropical waves,” places west of the wave (in the Northern Hemisphere) are typically afforded sunny skies. That was the dichotomy across Florida yesterday… To read the full story, click here - http://www.weatherworks.com/lifelong-learning-blog/?p=1386 © 2017 H. Michael Mogil To learn more about how to read/interpret various maps and charts used by meteorologists, be sure to click here!   DISCUSSION: Over the past few days, a massive ridge over the West Coast has been dominating the weather stories in the region with the Pacific Northwest reaching near and above 100 degrees Fahrenheit including in Portland, Oregon. However, the massive ridge also brought moisture into California. The moisture slowly crawled up the state of California in the form of high clouds, thunderstorms, and rain. The monsoon made its first stop in Santa Barbara Coast especially where there was slight rain on Tuesday followed by thunderstorms on Wednesday.
However, the moisture wasn’t quite enough as the showers were generally hit and miss in some areas. For example, the San Francisco Bay Area had some locations with a few drops even enough to barely tip the bucket in some locations such as San Francisco and San Jose while some like Livermore had received about seven hundredths of an inch in a day. However, no real thunderstorms occurred in the San Francisco Bay Area as much of the convective activity was positioned just off the coast on the edge of the Eastern Pacific Ocean near Half Moon Bay. Also, there were thunderstorms over parts of the Sierra Nevada mountains as well as the San Joaquin Valley, especially where the Detwiler fire is burning. Also, there happened to be little to no Convective Available Potential Energy (CAPE), which is a measurement of buoyancy related to the updrafts of thunderstorms, according to the soundings at Oakland, Vandenburg Air Force Base, and San Diego while Reno had observed about 100-200 joules per kilogram. Another phenomenon that happened during this monsoon flow was a few heat bursts, which occurs on occasion after a thunderstorm dissipates; although not much is known about them. The heat bursts had occurred over some parts of the San Francisco Bay Area, including in the City of Oakland. Chief Meteorologist A.J. Fox of KSEE 24 News in Fresno said that the cloud cover and humidity helped Fresno set a record with a morning low temperature of 85 degrees on August 3rd. Fox also mentioned that there were several grass fires in the San Joaquin Valley due to the lightning strikes affiliated with the monsoon as well as dried up grass. San Jose also had a very high low temperature of 74 degrees on the morning of August 4th. However, the extremely high low temperatures were short-lived as the temperatures dropped the next day according to the National Weather Service office in Monterey, California. This monsoon is a yearly event during the summer where moisture gets drawn up into California from Arizona. To learn more about other high-impact weather events occurring across North America, be sure to click here! ©2017 Meteorologist JP Kalb  DISCUSSION: As a larger-scale low-pressure system gradually continues to head eastward across portions of southeastern Canada, there will be a continued threat for showers and storms overnight across portions of both coastal and interior sections of the Northeastern United States. This is a direct result of a slow-moving cold front gradually pushing convection along a north-to-south line further east with time during the overnight hours now and on into earlier Saturday morning. Although there is currently only a single flash flood warning effect on the southern flank of this relatively linear area of convection across eastern Pennsylvania, there are still many reports of lightning in the vicinity of this nocturnally-persistent convection and this will be likely to continue due to the continued presence of decent convective instability through the overnight hours. This continued convective instability will be largely due to a persistent flow of warmer and substantially moistened air associated with the more southerly flow pumping northward just ahead of the slowly advancing cold front. Hence, tonight will continue to be a rainy one for many people living across eastern Pennsylvania, southern/central New Jersey, and southeastern New York.
To learn more about other high-impact weather events occurring across North America, be sure to click here! ©2017 Meteorologist Jordan Rabinowitz    An active pattern continues for portions of the Mid-Atlantic Friday into Saturday. The pattern is similar to East Coast snow storms with a ridge in western and central portions of the United States, a ridge in eastern Canada, a trough in the eastern United States, as well as a ridge in Greenland. These factors point to a rare summer coastal storm developing late tomorrow into the day on Saturday.
This storm will track off the Delmarva Peninsula, and meander there for a while before weakening and moving out into the open waters. With PWAT values over 2 inches and dew-points temperatures in the lower to mid 70 degrees across portions of the region Friday night, as shown in the images above (credit: WeatherTap.com), there is plenty of moisture to work with which will lead to rounds of heavy showers and some embedded thunderstorms. National weather service offices have issued flash flood watches across portions of Pennsylvania, West Virginia, northern Virginia, Maryland, central and southern New Jersey, and Delaware, for flooding rains as shown in the image above. A general 2-4 inches will accumulate across the area with locally heavier amounts likely. Breezy winds on the coast will also be a threat as it intensifies and tightens up the pressure gradient along the coast. One thing is for certain, if this type of pattern, and much of this summer’s overall pattern were in place this past winter, the Northeast and Mid-Atlantic would have experienced a more active and colder winter. This also begs the question; will this pattern have any influence on this winter? To learn more about other high-impact weather events occurring across North America, be sure to click here! ©2017 Forecaster Joseph DeLizio |
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