DISCUSSION: Of increasing interest lately comes the desire to visit warmer locations despite summer’s arrival in the Northern Hemisphere. Hawaii, the United States 50th state often is one of those locations seemingly on everyone’s list, often with winter a great time to visit as temperatures are within just a few degrees of 80 and typically a great time to see the migration of whales from the eastern Pacific into the warmer waters surrounding the island chain.
As Hawaii moves into spring, like the rest of the United States, it comes with a meteorological phenomenon dubbed what locals call Lahaina Noon. Lahaina noon is stated to be a solar occurrence to where the sun passes directly overhead at solar noon. Hawaii is the only state to experience such due to the “subpolar point (the location on a planet where its sun is perceived to be directly overhead, that is where the suns rays are hitting the planet perpendicular to its surface (Ridpath).” For Hawaii and other locations within the Tropic of Cancer and Tropic of Capricorn received the sun’s direct rays as the apparent path of the sun passes overhead before the summer solstice and retreats towards the equator.
According to the US National Weather Service – Honolulu Forecast Office, it is expected that Hilo will see Lahaina Noon May 18th at 12:26PM, Kahului – May 24th at 12:22PM, Honolulu – May 26th at 12:28PM and Lihue – May 31st at 12:35PM (NWS). Viewers can see this sight by standing outside at these times in the stated locations. On these says the sun will appear exactly overhead, any object standing upright will appear to have no shadow.
For this and other information on meteorological and optical phenomena visit the Global Weather and Climate Center for updates!
© Meteorologist Jessica Olsen
Mike Shanahan, Bishop MuseumPosted on April 30, 2017 12:05 am. "Lahaina Noon will strike isles next month." Honolulu Star-Advertiser. N.p., 30 Apr. 2017. Web. 20 May 2017.
Ian Ridpath, ed. (1997). "subsolar point". A Dictionary of Astronomy. Oxford; New York: Oxford University Press. ISBN 0-19-211596-0. The point on the Earth, or other body, at which the Sun is directly overhead at a particular time.
US Department of Commerce, NOAA, National Weather Service. "National Weather Service Weather Forecast Office." National Weather Service Forecast Office - Honolulu, Hawai`i. NOAA's National Weather Service, 07 Nov. 2004. Web. 20 May 2017.
DISCUSSION: In light of the recent severe weather event which impacted many parts of the south-central United States, there was strong outflow emanating from the leading-edge of certain severe thunderstorms which impacted parts of southern Missouri. As you can clearly see in the image attached above, a neat cloud referred to as a "roll cloud" was observed by many people across the region as a particular thunderstorm. It is worth noting that roll clouds form as a result of very strong and efficient lifting of warm moist air ahead of an approaching strong-to-severe thunderstorm line. As this warm, moist air was quickly lifted over the leading-edge, the roll cloud formed as a consequence of rapid condensation of low-level moisture aggregating into what could be visualized as a roll cloud as shown above. Hence, in any situations wherein a roll cloud moves through a given region out ahead of a strong-to-severe thunderstorm, a roll cloud is typically an indication of a powerful thunderstorm approaching the given region.
To learn more about other educational topics in meteorology, be sure to click here!
©2017 Meteorologist Jordan Rabinowitz
DISCUSSION: In light of the moderate risk issued for much of Oklahoma and northern Texas for the afternoon and evening hours today, the WeatherTAP Facebook team was inspired to post a series of graphics which help to explain how supercell thunderstorms work in typical large-scale convective situations. Attached below is a compiled explanation of how supercell thunderstorms are typically approached by storm chasers and what reasons that approach is taken.
"With a moderate risk for severe storms in western Oklahoma today, you're likely to see some radar images of some supercells. Supercells are uniquely structured and quite complex. I found three images that I hope will help you understand the complex structure of supercells. Often, the best place to be as a chaser is just to the south of the hook. Before we can even get supercells we need four things to happen: wind shear, instability, moisture, and lift."
To learn more about other neat weather educational topics, be sure to click here!
©2017 Meteorologist Jordan Rabinowitz
DISCUSSION: In light of National Hurricane Awareness week now coming to an end, it is worth acknowledging how the Hurricane Hunter Reconnaissance Aircraft recently took a tour through several major locations along the East Coast of the United States. The various pilots and scientists who fly aboard various missions play a critical role in helping to improve the quality of hurricane intensity and track forecasting across both the Tropical Atlantic and Tropical Eastern Pacific basins. By greatly increasing the amount of data which gets injected into computer forecast models for tropical cyclone forecasting, such data from these Hurricane Hunter aircraft allow hurricane specialists at offices such as the National Hurricane Center to better understand how a storm may evolve in time with greater accuracy. The image above captures some perspectives of the 2017 Hurricane Awareness Tour at Opa Locka Executive Airport. In the images attached above, you are looking at the NOAA P3 used mainly to fly research missions in and around tropical cyclones. This content is courtesy of the NBC 6 news team.
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©2017 Meteorologist Jordan Rabinowitz
DISCUSSION: As temperatures warm and much of the country is thoroughly into its spring weather, California’s Central Coast is wrapping up its wet winter weather which brought unprecedented rains to much of the state, diminishing all D3-D4 drought indices for the state. While the state transitions to warmer surface temperatures as summer approaches, a common weather phenomena can be seen along the coast, fog. This fog and its water vapor rich friend the marine layer can impact traffic, air travel and ultimately overall visibility in coastal locations and some inland locations where valleys are prevalent.
The National Weather Service states, “the marine layer represents a difference between a cool, moist air mass and a warmer air mass.” The marine layer in a sense is similar to a sea breeze in that a sea breeze is a local wind that blows from sea to land, which is often caused by the difference in temperature when the sea surface is cooler than the nearby land mass. The marine layer in the coastal areas of California often affects visibility, as its suspension of water droplets, and salt form the critical condensation nuclei needed for this fog formation.
The San Francisco Bay area including the California coastline is quite susceptible to this phenomenon. We should expect to see more of the marine layer and fog to roll in on a consistent basis as forecasts call for cool sea surface temperatures coming on contact with cooler dense air which creates the inversion for a layer of these stratus clouds to form or fog if the cloud layer does not lift enough.
Below is current video of satellite footage for 1900Z of the Monterey Bay Area, notice the lack of inland breach of the marine layer into the Monterey area!
For information on this and other weather phenomena visit the Global Weather and Climate Center!
~Meteorologist Jessica Olsen
Service, National Weather. "The Marine Layer." NWS JetStream - The Marine Layer. N.p., n.d. Web. 10 May 2017.
Video: Naval Research Lab, Monterey Bay May 10th, 2017