North America Weather Headlines - Global Weather & Climate Center

Heavy Rainfall Threatening The Mid-Atlantic Region! (credit: Meteorologist Sheldon Kusselson)

9/27/2016

DISCUSSION: If you live in the Mid-Atlantic portion of the United States (centered on the Washington DC area), be prepared for a heavy rain (and possible flooding) event, even though it has been dry for the past month. Moisture coming from all over the place at different levels of the atmosphere and you can take note with this moisture analysis from different polar and geostationary satellites.

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~Meteorologist Sheldon Kusselson

“Isolated” Showers: What Exactly Does this Mean? (Credit: NWS Louisville, KY)

9/26/2016

DISCUSSION: On September 18, 2016, the National Weather Service (NWS) Louisville, Kentucky forecast office released an Area Forecast Discussion at 3:18 p.m. EDT, which forecasted a potential isolated shower/sprinkle for far eastern parts of the state. Now, you often hear weather forecasters use the term “isolated showers”. But, what exactly does the NWS consider “isolated”?

A shower or thunderstorm that is “isolated” refers to rainfall/thunderstorms that will potentially cover approximately 10%-20% of a county viewing area or region. More specifically, very few locations will possibly receive rainfall while majority of the viewing area might remain mostly dry of precipitation. If a forecast anticipates isolated showers/thunderstorms, then a meteorologist will often highlight more specific locations (i.e. small cities, neighborhoods, small towns) that may receive rain or thunderstorms.

The NWS Louisville forecasters illustrated the perfect definition of “isolated” showers by exhibiting radar-estimated rainfall amounts for two separate isolated shower systems (radar-estimated rainfall amounts can vary from actual ground rainfall estimates). The blue-green coloring on the radar imagery (above) displays the sparse regions that received rainfall at 8:38 p.m. EDT on September 18, 2016. In the left-most image, the neighboring areas located east of Green Grove received a maximum radar-estimated rainfall amount of 1.3 inches. The right-most radar imagery specifies a radar-estimated amount of 0.8 inches in a secluded location just north of Nonesuch, Kentucky. Therefore, only these two areas received “isolated” showers since the precipitation coverage occurred in a small vicinity of the state.

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~Weather Forecaster Aisha Murphy

Summer-like Heat continues for Midwest! (credit: National Weather Service)

9/24/2016

Discussion: Today marked the official start of astronomical Fall. Yet, across the Midwest, temperatures painted a different picture. This week, the Midwest has experienced Summer-like temperatures, with highs ranging between the upper 80’s and lower 100’s, as well as heat indices in the mid to upper 100’s .This was due to a ridge of high pressure hovering over the central United States throughout the week. Temperatures have been several degrees above-average for the month of September across many parts of the Great Plains. The combination of high temperatures and particularly dry air were sufficient enough for the issuance of a heat advisory was issued for parts of Oklahoma on Monday (A rare occurrence for that part of the country during the month of September).

However, this Summer-like heat and dry weather is expected to come to an end soon, as a cold front is forecast to move through this weekend. While this cold front should bring some relief from the hot, dry weather it will also bring a renewed threat for flooding and/or flash flooding with rainfall amounts of 1 to 3 inches possible. It does not appear that this system will produce much in the way of a severe weather threat, aside from some thunderstorms capable of producing gusty winds. The cold front is forecast to move out of the area by late Sunday. Thereafter, temperatures should return to normal, with highs in the upper 60’s to lower 70’s.

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~Meteorologist Noah Hardy

Omega block expected across western North America… (H. Michael Mogil, CCM, CBM, DMS)

9/19/2016

Computer models keep suggesting the development of an “omega block” across western Canada by late this week. Such a block can involve a splitting of the overall upper level wind flow by a closed high to the north and a closed low to its south. Alternatively, the pattern can involve…To read the full story, click here - http://www.weatherworks.com/lifelong-learning-blog/?p=1006

Tracking Tropical Depression Julia’s Return to the Atlantic Coast (Credit: National Hurricane Center)

9/18/2016

DISCUSSION: After maintaining a stationary position near the Carolinas, Tropical Depression Julia is now heading in a north-northwestward direction at 7 mph with 30 mph (25 knots) maximum sustained winds and gusts up to 40 mph. The minimum central pressure level of the tropical depression has deepened to 1010 mb (down from a minimum central pressure of 1020 mb as of later yesterday). Typically, a lower minimum central pressure observation is indicative of a period of strengthening occurring given conducive environmental conditions. According to the National Hurricane Center (NHC), global and regional model disagreements suggest that Julia could either weaken into a remnant low or deepen into a slightly stronger storm over the next 48 hours. The NHC concludes that Julia could actually migrate northward and approach the southeastern coast of North Carolina approximately between 2 p.m. EDT Monday and 2 p.m. EDT Wednesday. To learn more about other high-impact weather events from across North America, be sure to click here!

~Weather Forecaster Aisha Murphy

Tropical Depression Julia Stirs Up Problems Along the Carolina Coasts (CREDIT: National Hurricane Center, NOAA, NWS)

9/17/2016

DISCUSSION: After meandering off the coast of the Carolinas, Tropical Depression (wind speeds less than 39 mph) Julia remains stationary in the Mid-Atlantic with 30 mph maximum sustained winds. The winds are expected to produce high tidal flooding and a moderate-to-high risk for rip currents near low-lying coastal areas along southeast South Carolina (e.g., Colleton, downtown Charleston and Beaufort). The Charleston, SC National Weather Service Forecast Office has issued a high tide advisory, which will take effect at 9:15 p.m. EDT. By this evening at 8 p.m. EDT, the depression is projected to transition towards becoming a post-tropical storm (remnant low) as it gradually moves due north and northwestward between 25 and 30 mph. By tomorrow, the coastal regions in the Carolinas, Georgia, and Virginia could possibly receive scattered rainfall, coastal flooding and gusty wind impacts as a consequence of Julia’s offshore presence. As of now, the National Hurricane Center (NHC) has forecasted the potential dissipation of Julia to occur by tomorrow morning around 8:00 a.m. EDT. To ensure safety, it is in everyone’s best interest to stay away from the beaches to avoid high surf and rip currents. To learn more about other high-impact weather events from across North America, be sure to click here!

Weather Forecaster Aisha Murphy

Meteorologist Joe Cioffi Discusses The Issues Surrounding Tropical Depression Julia!

9/17/2016

DISCUSSION: Wondering what the latest situation is in regards to the status of the remnants of Tropical Storm Julia? Attached below (courtesy of WPIX TV CH 11 FiOS1 News Meteorologist Joe Cioffi), is a discussion concerning the near-term forecast for what currently is Tropical Depression Julia as it meanders just off the Mid-Atlantic coastline over the next couple of days! A great watch for anyone along the East Coast of the United States and tropical enthusiasts everywhere!

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@Meteorologist Jordan Rabinowitz

Early Fall Freeze Warnings for the Northwest! (Credit: NWS Spokane, WA)

9/12/2016

As the calendar heads farther into September, the Northwest is starting to see the first signs of fall. The official first day of fall is not until September 23rd, 2016 and a freeze warning has been issued for some of the valleys across Northern Washington and parts of Idaho. With clearing skies and light winds, temperatures are expected to drop into the low 30s and even upper 20s in parts of the warning area. These temperatures pose a threat to any vegetation and gardens that are uncovered because it is still growing season. Not all areas will see these chilly temperatures as shown below in the graphic from the National Weather Service in Spokane, Washington. It is a sign that the summer nights are fading fast! To learn more about other high-impact weather events from across North America, be sure to click here!"

Strong Storms Barrelling Through Parts of New England! (credit: www.weathertap.com)

9/11/2016

DISCUSSION: As much of the United States remains fairly quiet this morning, the back-end of a cold front associated with a large low pressure system (whose low pressure center is now over Central/Northern Quebec) which is quickly exiting the Northeast corridor. As it does so, it continues to generate strong thunderstorms along the north-to-south axis of the eastward-moving cold front. During the past few hours, there have been several severe thunderstorm warnings issued by the National Weather Service office located in Gray, Maine as a result of there being an efficient trend for destabilization of air parcels positioned along and ahead of this northeastward-moving cold front. Therefore, folks who are currently located in far eastern portions of New England will definitely want to remain updated by your local National Weather Service office, your weather radio, smartphone weather alerts, etc.

Although the primary threat from the majority of the stronger convective cells within this longer line of convection has predominantly been characterized by strong, gusty winds there have also been numerous reports of lightning. Based on the fact that lightning is one the leading causes of death and injury from severe weather events, if you hear thunder, it is imperative to take adequate shelter. This is due to the fact that even if the storm producing the lightning is several miles away, you are still close enough to be struck by lightning. As the National Weather Service slogan says "If thunder roars, go indoors!" It is worth noting that upon the passage of the aforementioned cold front, conditions will swiftly improve due to the atmosphere returning to a state of increased stability as cooler and drier air filters into the Northeast from Southeastern Canada. To learn more about other high-impact weather events from across North America, be sure to click here!

@MeteorologistJordanRabinowitz

Wet weather continues for the Midwest! (credit: www.weathertap.com)

9/10/2016

DISCUSSION: The Midwest is experience more wet weather tonight as a deep layer of moisture from the Pacific continues to exert its influence over the region. The Midwest already got a small taste of this wet weather today as storms moved through the region early this morning, with some areas receiving as much as 2 inches of rain. Warm, moist air from the Gulf of Mexico has been fueling the storms as they continue move across the Midwest ahead of a cold front that was positioned over the Rockies. The moisture has been situated along a ridge stretching from Missouri to Eastern Kansas as it struggled to head north. However, a nocturnal jet (fast-moving wind current surrounded by slower moving air) helped to push the moisture northward Thursday evening. Precipitable water values (Measure of the depth of liquid water at the surface that would result after precipitating all of the water vapor in a vertical column over a given location) are around 2 inches, which means these storms can be expected to efficiently produce rainfall tonight.

The cold front ahead of the warm air is forecasted to merge with the warm, moist air, providing additional energy to the system, which could lead even heavier rain as well as the possibility of severe storms this afternoon/evening. The severe threats from these storms will most likely be marginally large hail, high winds, and heavy rain. The heavy rain from this afternoon/evening combined with the rain on Thursday morning and evening will continue the threat of flooding and flash flooding for the area. However, after this system moves through, cooler temperatures will prevail leading to gorgeous weather through the weekend. To learn more about other high-impact weather events from across North America, be sure to click here!

@Meteorologist Noah Hardy

Newton weakens; brings flash flood threat to parts of Arizona and New Mexico… (H. Michael Mogil, CCM, CBM, DMS)

9/7/2016

As quickly as Newton formed, it has begun its demise. Moving across rough terrain in northwestern Mexico, Newton has been downgraded to tropical storm status early this Wednesday morning. Heavy rainfall and flash flooding remain the greatest risks from Newton…To read the full story, click here - http://www.weatherworks.com/lifelong-learning-blog/?p=995

Hurricane Newton Remains a Serious Concern! (credit: NWS Tuscon, Arizona)

9/6/2016

DISCUSSION: A weakening Hurricane Newton continues its northward journey out of the far Eastern Pacific Ocean, through the Gulf of California, and towards the Southwestern United States. As it continues to do so, there will be an increased threat for persistent, heavy rainfall across southern to central parts of Arizona as well as New Mexico. That being said, based on the fact that this Category 1 hurricane is currently situated approximately over the northern part of the Gulf of California with the deepest moisture associated with Newton located north and northeast of this tropical low pressure system's circulation center. This is further supported by the atached animated forecast graphic courtesy of the High-Resolution Rapid Refresh (HRRR) model centered over the region of concern.

Based on the information explained in the post linked above (courtesy of the National Weather Service office in Tuscon, Arizone), this continues a concerning situation due to the continued threat emanating from Hurricane Newton. The primary reason for this heightened concern for this hurricane's second landfall in Southern/Central Arizona and parts of New Mexico is the more variable (and elevated) terrain spread across the Southwestern United States. With more elevated terrain, there is inherently an increased threat for both heavier rainfall (i.e., which often occurs as a consequence of increased orographic enhancement as air parcels are forced to rise over the more elevated terrain) and subsequent flooding which ensues as the heavy rainfall runs through and down valleys positioned between the areas of higher terrain. Therefore, this threat will persist for the next 24 to 48 hour or so, until the bulk of the heaviest precipitation associated with what will eventually be Tropical Storm and then Tropical Depression Newton moves further east and northeast. To learn more about other high-impact weather events from across North America, be sure to clickhere!

Hurricane Newton Targets Northern Mexico and the Southwestern U.S.! (credit: NWS El Paso, TX)

9/5/2016

DISCUSSION: As what was formerly Tropical Storm Newton earlier this afternoon (but what is now Hurricane Newton) continues its march northward towards the Baja Peninsula and beyond, there will be an increased threat for the commencement of impacts from the North American Monsoon circulation over the next several days. This increased North American Monsoon threat will be the result of impacts from both the inherent moisture advection associated with Hurricane Newton (i.e., eventually Tropical Storm and ultimately Tropical Depression Newton after landfall) and a weak low-pressure system which will become nearly stationary in the coming days across the Four Corners region of the Southwestern United States.

As the aforementioned low-pressure system begins to ingest and interact with the deeper tropical moisture associated with Newton, this will bolster the potential for persistent, heavy rainfall across areas within (but not limited to): Central-to-Eastern Arizona as well as parts of Western New Mexico. More details can be found within the graphic attached above courtesy of the National Weather Service office in El Paso, Texas! To learn more about other high-impact weather events from across North America, be sure to click here!

Why Is Hermine Taking It's Time? (credit: ZoomRadar via Meteorologist Jeff Berardelli)

9/4/2016

DISCUSSION: As what still remains to be Post-Tropical Storm Hermine continues to slowly travel northward just offshore from the Mid-Atlantic coastline, many questions have surfaced amongst people in the respective states which have been, are, or still still remain at least partially in this storm's path. The leading questions concern the future track of this storm based on many meteorologists explaining the high-degree of variability which still exists in terms of the various trajectories this post-tropical (and possibly soon to once again be tropical) system may take in the not-too-distant future (i.e., over the next 48 to 72 hours). Barring this high degree of uncertainty tied to the forecast at this time, there still remains a to be a legitimate reason for this uncertainty (as illustrated by the animated graphic below). More specifically, this animated graphical rendering of the current larger-scale synoptic flow regime in place across the Eastern United States, the western Atlantic Ocean, and parts of Atlantic Canada reflect the sheer complexity of the current weather pattern which will directly govern the future track of this system.

To be more precise, here is a quote from the original post written by Meteorologist Jeff Berardelli which provides a perfect explanation for the future of this storm. "Hermine is going to merge with another weather system which will re-energize and stall Hermine. The weather system it will merge with can be looked at as a weak front at the surface, an upper level low aloft and essentially a piece of the jet stream. Once Hermine merges and then emerges off the Virginia coast it will move over the very warm Gulf Stream waters. High pressure will build southward into New England and trap Hermine. So what you have is a storm of hurricane strength sitting just offshore of New Jersey/ Del Marva Sunday, Monday, Tuesday and perhaps longer. The coast will likely see winds gusts near hurricane force Sunday late-Monday (depending on how close the storm meanders), offshore waves of 25-35 feet and the worst impact of all will be significant, and potentially record coastal flooding from Southern NJ south to Virginia. Why potentially record setting? Well, when you have a storm of hurricane force barely moving for 3 days you continually pile up the water against the coast, back bays, nooks and crannies. Will the coastal flooding be equivalent to Sandy? No, not quite. But might it be the worst coastal flooding residents from South Jersey to Virginia have ever seen. Remember Sandy's worst coastal flooding was mainly from Atlantic City northward. Although we can't pinpoint the exact location of the impacts yet it does look like the coastal flooding will extend much further south."

Collectively, it reflects one of the more complicated forecast evolutions which a meteorologist anywhere will ever contend with and will eventually make for another avenue of excellent research work and future study. To learn more about other high-impact weather from across North America, be sure to click here!

Post-Tropical Storm Hermine Remains A Threat For the Coastal Northeast! (credit: NWS Upton, New York)

9/3/2016

DISCUSSION: As of late this evening, the forecast (i.e., the projected track for what still remains to be Post-Tropical Storm Hermine) has changed somewhat from earlier forecast thinking for Hermine. The main difference is characterized by the most likely future track of this system to take more of a westerly track than previously expected over the past 24 to 36 hours. The main result of this newer thinking in the future trajectory of this re-strengthening sub-tropical (but what soon re-gain status as a tropical) system will be the proximity of the worst impacts from Hermine to the greater tri-state area over the next 48 to 72 hours.

As discussed in the graphic above (courtesy of the National Weather Service off in Upton, New York), the official status of the storm being defined as either tropical as opposed to sub-tropical will not make a tremendous difference overall with respect to the coastal and semi-inland impacts from this low pressure system. More specifically, aside from breezy to gusty winds episodically moving through the tri-state area, there will be a substantially increased threat for coastal flooding when the larger wave action (and potentially lower-end storm surge influence) becomes synchronized with the high tide cycles that come about between later in the day on Sunday and likely through earlier in the day on Tuesday. To learn more about other high-impact weather events from across North America, be sure to click here!

Post-Tropical Cyclone Hermine Threatening Parts of Coastal Northeast! (credit: NWS Upton, New York)

9/3/2016

DISCUSSION: As Post-Tropical Cyclone Hermine continues to slowly move off to the east (and eventually off to the north/northeast), there will be an increased threat for heavy rainfall and gusty winds along the New Jersey, New York, and parts of the New England coastline in the coming days. Currently, this Post-Tropical Cyclone which may re-gain hurricane status within the next 24 hours or so, is positioned roughly 130 miles to the east-southeast of Norfolk, Virginia and may approach the New York City metro area as well as points to the east within the next 48 to 72 hours. As a result of this projected forecast track, Tropical Storm Warnings have been issued for the NYC metro area as well as parts of New Jersey, Long Island, and southern Connecticut. Despite that these are only Tropical Storm Warnings (and regardless of the exact track which Hermine ends up taking), this sub-tropical/tropical storm will undoubtedly produce tremendous flooding, beach erosion, and even a minor storm surge along the coastlines of New Jersey and Long Island. Therefore, now is the time to making your preparations ahead of the deteriorating conditions which will likely begin to move in by around Sunday afternoon.

It is imperative to bear in mind that a Tropical Storm Warning means that tropical storm conditions (i.e., sustained winds between 39 and 73 MPH with potentially higher gusts) are expected to move through the aforementioned region. Despite, this not appearing to be an overly dangerous situation over the next few days, there will almost certainly be an increasing threat for downed power lines and falling trees due to the persistent rainfall weakening the soil and therefore the root systems of trees. Hence, this strong low pressure system will bring an indirect storm threat to both life and property. Therefore, if you do not need to be outdoors during the worst of the tropical storm conditions as they move through parts of the tri-state area over the next few days, it would be in your best interest to avoid doing so.

Tropical storm conditions will most likely abate by around Wednesday afternoon (or possibly a little earlier or later on depending upon the exact forward speed of Hermine over the next couple of days). It is quite possible that during your travels over the next few days, you may encounter downed trees, downed power lines, and/or flooded roadways. If this becomes the case, be sure to navigate around these areas so as to remain out of harms way. If you are going to be flying in or out of the greater NYC metro area (e.g., JFK International, Laguardia, Newark, Islip, etc.) do your best to plan ahead NOW and call your travel carrier for information before this become more chaotic over the next 24 hours. Bottom line, this will not be a knock-out blow by any means but will certainly have a noticeable impact on local and national travel networks around the country so be safe and alwsys err on the side of caution these next few days. To learn more about other high-impact weather events from across North America, be sure to click here!

Tropical Storm Hermine is now getting weird (H. Michael Mogil, CCM, CBM, DMS)

9/3/2016

DISCUSSION: Take a look at today’s early morning (Sept. 3, 2016) Hermine forecast track from the National Hurricane Center - NHC (Fig. 1) and you’ll see several things appear to be, well, just plain weird. However, there is some good rationale behind each of these…To read the full story, click here - http://www.weatherworks.com/lifelong-learning-blog/?p=991

Hermine Making Landfall Just South of Tallahassee, Florida! (credit: Tornado Quest via Radarscope)

9/1/2016

DISCUSSION: As Hurricane Hermine begins the process of making its official landfall along the Gulf Coast of the Florida Panhandle, very strong winds will continue battering the west-to-east coastline across this region. That being said, despite the fact that this storm is a relatively weak hurricane, the strong onshore flow which is clearly evident based on the embedded deeper blue (pink) shading on the east(west) sides of this tropical storm's circulation provide a strong indication of tropical storm to hurricane-force winds which are almost certainly reaching the surface along and just inland from the immediate shoreline at this time. Additionally, another point of concern is the dramatically increased threat for storm surge-based flooding and the bulk of the onshore flow maximizes as the center of Hermine moves ashore which will have the effect of pushing all of the deeper wave action near the eastern-half of the center of the storm towards to coves and bays just to the south and west of Perry, Florida (located to the east of St. Marks as seen in the image above as a point of reference). To learn more about other high-impact weather events from across North America, be sure to click here!

Impressive view from @NWSTallahassee of #Hermine velocity data with landfall imminent. #flwx (11:25PM EDT) pic.twitter.com/UquaOCji9h
— Tornado Quest (@TornadoQuest) September 2, 2016

Flooding Potential Increase With Landfall of Hermine! (credit: NWS Weather Prediction Center)

9/1/2016

DISCUSSION: As a strengthening Hurricane Hermine continues to makes its final approach into Northern Florida (and specifically with the most significant impacts likely expected to be felt across the span of the Panhandle), there will remain a much larger threat for widespread flooding over the next few days. This increased flooding threat will be a direct consequence of Hurricane Hermine weakening coupled with a persistent flow of tropical moisture with a northeasterly trajectory along the East Coast of the United States. This northward-moving moisture-laden air will generate an increased potential for longer-duration periods of heavy rainfall anywhere from Northern Florida to the Mid-Atlantic region due to the weakening tropical storm's slow rate of northward movement over the next few days. Bearing that in mind, it is imperative to quickly organize your preparation plans for this tropical storm immediately in order to be prepared well ahead of its arrival. Timing it out, the center of a much weaker Tropical Storm (or possibly Tropical Depression) Hermine should be located just offshore from the South Carolina coastline by early Saturday afternoon which will be bring the heaviest rainfall to the Carolinas as well as points further north by later in the day on Saturday! To learn more about other high-impact flooding events from around the world, be sure to click here!

Hurricane Hermine Bears Down on the Florida Panhandle! (credit: The Weather Channel)

9/1/2016

DISCUSSION: As a strengthening Hurricane Hermine continues to bear down on the Florida Panhandle and surrounding areas, there will be increased presence of both persistent and heavy rainfall coupled with strong onshore flow which will increase both wave heights (and consequently the prevalence of beach erosion along much of the Gulf Coast-facing beaches across Northern and Western Florida. Attached below is a current live feed courtesy of the The Weather Channel which has a crew set-up down in Cedar Key, Florida ahead of the upcoming landfall of Hurricane Hermine late tonight. At this time, Hurricane Hermine remains a Category 1 hurricane with maximum sustained winds of 75 MPH with a minimum central pressure of 988 mb. Stay tuned for more updates later tonight on this developing situation and to keep tabs on other high-impact weather events from across North America by clicking here!