*******Note that forecasts and outlooks in this post are NOT the official forecast from the National Hurricane Center (NHC). They are my own detailed views on the Atlantic tropics based on current observations and latest computer model runs. As such do not make decisions based on my posts...consult news media...watches and warnings from your local weather office...and any evacuation orders issued by local governments to make the most informed and best decisions. Visit the NHC website hurricanes.gov (hurricanes dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.**********
...SUNDAY MAY 22 2022 10:25 PM EDT...
Continuing daily birdseye view posts on the Atlantic tropics even though hurricane season does not start until June 1st... due to the following two disturbances:
(1) Rapidly forming northeastern Gulf of Mexico mid-level low pressure... see area of interest #3 section below for more information.
(2) Deep-layered low pressure cyclone in the open central Atlantic which has potential to acquire tropical characteristics tomorrow and Tuesday... see area of interest #2 section below for more information.
New to this site this year... I will be sequentially numbering up areas of interest for possible Atlantic tropical development. In this scheme... will reset back to #1 at the start of next year (January 2023). The current areas of interest are designated #2 and #3 as I designated the first one of this year earlier this month (in birdseye view posts #1 to #9 on the home page). This scheme is to reduce confusion as Atlantic tropical activity increases during the peak of the hurricane season... when multiple simultaneous areas of interest begin and end which previously required shuffling around the area of interest numbers from update to update.
AREA OF INTEREST #2... As annotated in the above birdseye view chart... a warm core deep-layer ridge across the western Atlantic remains supported by an ongoing fetch of northward warm air transport across the east coast of North America. This ridge has cut-off an upper trough that was previously in the northwest Atlantic into a central Atlantic upper vortex. The surface frontal cyclone previously birthed by the divergence zone of the upper trough has whirled into the center of the upper vortex. The end result is a deep-layered low pressure cyclone in the central Atlantic which will be monitored for acquisition of tropical characteristics Monday and Tuesday... in particular as the cyclone drifts south into warmer water temps under the steering influence of the deep-layered ridge.
The updated forecast track in the outlook below is nudged southwest as the latest model data suggests the upper vortex of the deep-layered low pressure cyclone will be a little further to the south and west compared to previous model runs. This places the cyclone over 21.5 deg C water by Tuesday... about 1 deg C higher than the previous forecast. Therefore I have raised peak subtropical cyclone development odds to 20% in this update. Although these water temps are below the typical 26+ deg C associated with tropical development... upper air temps may be cold enough for instability and thunderstorm generation (for Monday and Tuesday... the GFS model is currently forecasting a 200 mb height of 1191 to 1194 dekameters in association with the cold core upper vortex to be tied to this deep-layer low pressure cyclone). Models are also in agreement that the surface structure of the cyclone will maintain a broad circular shape with a well-defined center through Tuesday... also needed for subtropical cyclone development. Subtropical development odds at 72 hours are lowered to 0% as the cyclone is forecast to move northeast to cooler water. The northeast track in the longer range is anticipated as the current upper trough energy over the northern US and central Canada is expected to break through the deep-layered ridge and grab the deep-layered low pressure system.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (1800Z May 23)...10% chance of subtropical cyclone formation (central Atlantic near 35N-48W)
IOH 48 Hr Outlook (1800Z May 24)...20% chance of subtropical cyclone formation (central Atlantic near 34N-49W)
IOH 72 Hr Outlook (1800Z May 25)...0% chance of subtropical cyclone formation (north Atlantic near 37.5N-46W)
AREA OF INTEREST #3... See special update #11A on the home page of this site which chronicles the formation of the new mid-level low pressure tropical disturbance in the northeastern Gulf of Mexico. This disturbance continues north and is already closing in on the eastern US Gulf coast while steered by the current western Atlantic deep-layer ridge. The well-defined center of rotation on satellite and Doppler radar is just offshore of the Florida/Alabama border region... and there is no confirmation of a closed surface spin needed for official tropical depression status. With a current lack of a thunderstorm burst at the center of rotation and time running out before the rotation moves ashore... it is unlikely that a closed surface spin forms with the rotation before landfall and thus I assess a 0% chance of tropical depression formation. This is my planned final statement on this area of interest on this blog.
In combination with the approaching eastern US cold front... this tropical disturbance is expected to bring locally heavy rain with possible flash flooding across southeastern Louisiana... eastern Mississippi... Alabama... Georgia… and western Florida panhandle over the next several hours.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (1800Z May 23)...0% chance of tropical cyclone formation (central Alabama near 33N-87W)
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/)
1200Z CMC Model Run...
**For area of interest #2...Current central Atlantic surface frontal cyclone drifts south while slowly weakening and reaches 33N-49W at 54 hours... moves northeast and reaches 38.5N-39.5W at 120 hours while becoming entangled with a frontal zone to the north.
**For area of interest #3... surface circulation becomes better defined while moving into southwestern Alabama at 24 hours... surface circulation loses definition over western North Carolina at 48 hours
1200Z ECMWF Model Run...
**For area of interest #2... Current central Atlantic surface frontal cyclone drifts south while slowly weakening and reaches 33N-49W at 48 hours... moves northeast and by 96 hours loses definition along a frontal zone sweeping in from the northwest
**For area of interest #3... surface trough becomes better defined across Alabama at 24 hours... moves east across North Carolina through 48 hours and evolves into a weak surface low offshore of North Carolina at 72 hours... drifts north offshore of mid-Atlantic US and ahead of frontal system that swings across the central US and Great Lakes region... loses definition when this frontal system arrives to the US east coast just after 96 hours
1200Z GFS Model Run...
**For area of interest #2... Current central Atlantic surface frontal cyclone drifts south and reaches 33.5N-48.5W at 48 hours... moves northeast and reaches 41N-43W at 90 hours where it becomes a broad elongated less tropical low pressure along a frontal zone sweeping in from the northwest
**For area of interest #3... no development shown
1200Z NAVGEM Model Run...
**For area of interest #2... Current central Atlantic surface frontal cyclone drifts south and reaches 33.8N-49.5W at 48 hours... moves northeast and reaches 42.5N-40W at 90 hours where it becomes a broad elongated less tropical low pressure along a frontal zone sweeping in from the northwest
**For area of interest #3... no development shown
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