MY 2022 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #2
*******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.**********
...THURSDAY MAY 5 2022 10:45 PM EDT...
Although Atlantic Hurricane Season does not officially start till June 1st... continuing daily birdseye view posts due to potential subtropical cyclone formation in the western Atlantic in the days ahead. Regardless of whether the forecast cyclone acquires tropical characteristics... it is expected to produce sea swells and rip currents for the mid-Atlantic and northeastern United States coast by this weekend. See area of interest #1 section below for more details.
AREA OF INTEREST #1... An amplified upper trough and associated surface low pressure ejecting eastward from the south-central US is expected to produce severe thunderstorms across the southeastern US over the next 24 hours... check your local and national news media for more info on this severe weather outbreak. Sliding east in tandem with this severe weather system is a current upper trough over eastern Canada.
By tomorrow a northeastern Pacific upper trough will pivot toward western Canada and support a vigorous surface frontal cyclone... with this cyclone’s warm southerly flow supporting a warm deep-layer ridge over central and eastern Canada. Per the ongoing computer model consensus... this ridge will in turn cut-off the aforementioned severe weather system and also a portion of the current eastern Canada upper trough into a western Atlantic upper vortex just after 48 hours. The eastern divergence zone of the upper vortex will trigger the formation of a broad surface cyclone... with the models also agreeing on the upper vortex and surface cyclone drifting west-southwest toward the southeast US coast in 3+ days under the influence of the Canadian deep-layer ridge. By days 4 and 5 I have low 10% odds of subtropical cyclone formation due to lukewarm low-20 deg C water and an upper vortex not very cold (1200 dekameter height at 200 mb... would like to see heights below 1200 dekameters for more confidence in instability for thunderstorms). It should be noted that as the surface cyclone and upper vortex move west-southwest closer to the warmer Gulf steam waters after day 5... the potential for more instability and higher subtropical development odds is on the table. Also note my forecast points in the updated outlook below have been nudged west compared to my previous blog post... as the latest GFS model data (around 48 hours) has trended with a more amplified and hence slower-eastward-moving upper trough in association with the southern US severe weather system.
A tight surface pressure gradient is expected to setup between the north side of the forecast surface cyclone and south side of the Canadian deep-layer ridge. This will drive a strong toward-shore wind and ocean flow for the northeastern and mid-Atlantic US east coast by this weekend... expect coastal sea swells and rip currents here regardless of whether or not the surface cyclone gets tropical characteristics.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (1800Z May 6)...0% chance of subtropical cyclone formation (Virginia/West Virginia/Kentucky border near 36.5N-82.5W)
IOH 48 Hr Outlook (1800Z May 7)...0% chance of subtropical cyclone formation (North Carolina/Virginia border near 36N-76.5W)
IOH 72 Hr Outlook (1800Z May 8)...0% chance of subtropical cyclone formation (western Atlantic near 35N-71W)
IOH 96 Hr Outlook (1800Z May 9)...10% chance of subtropical cyclone formation (western Atlantic near 33N-72.5W)
IOH 120 Hr Outlook (1800Z May 10)...10% chance of subtropical cyclone formation (western Atlantic near 33N-73W)
...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 #1...broad surface low pressure forecast near 33N-71W by 120 hours
1200Z ECMWF Model Run...
**For area of interest #1...broad surface low pressure forecast near 33N-71.5W by 120 hours
1200Z GFS Model Run...
**For area of interest #1...broad surface low pressure forecast near 32.5N-72.5W by 120 hours
1200Z NAVGEM Model Run...
**For area of interest #1...broad surface low pressure forecast near 33N-70.5W by 120 hours