*******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 29 2022 11:40 PM EDT...
Eastern Pacific Hurricane Agatha is expected to move northward into the Oaxaca region of southeastern Mexico over the next 24 hours while bringing damaging tropical storm to hurricane force winds... coastal storm surge... and heavy rainfall... see the NHC website at hurricanes.gov (hurricanes dot gov) for more information on Agatha as coverage on this site is focused on Atlantic basin tropical activity.
For the Atlantic basin... the remnants of Agatha to be located over southeastern Mexico... the divergence zones of upper vorticity currently over Florida and upper vorticity slowly approaching from the west coast of Mexico... and upper anticyclonic ridging to be located ahead of (east of) the upper vorticity will create a large region of disturbed weather with increasing rainfall spanning southeastern Mexico... the Bay of Campeche... Belize... western Central America... the western Caribbean.... western Cuba... the Cayman Islands... and the western Bahamas in the days ahead. Up to two areas within this disturbed weather pattern may consolidate into areas of interest for tropical cyclone formation.... see area of interest #4 and #5 sections 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 two areas of interest in this blog post are designated #4 and #5 as I designated the first three of this year earlier this month (in previous birdseye view posts 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 4... Computer models over the last several days have been steady in predicting the development of what is now eastern Pacific Hurricane Agatha. The models have also been and continue to be steady in their prediction of Agatha shifting northward into southeastern Mexico... with a corresponding northward shift in tropical development potential toward the Bay of Campeche or western Caribbean waters of the Atlantic basin. The northward shift in tropical weather away from the eastern Pacific and toward the Atlantic basin is anticipated as (1) the upper anticyclonic ridge in the region with its supportive outflow is beginning to expand north as the upper trough in the northwest Atlantic and upper vorticity currently over Florida are beginning to shift east and away... (2) as eastern Pacific Hurricane Agatha tracks north due to the ridge weakness induced by the current western North America upper trough... with surface convergence of Agatha and its eventual remnants helping to kick off thunderstorm activity toward the Atlantic basin’s Bay of Campeche and western Caribbean waters.
Whatever broad tropical low pressure emerges in the Atlantic basin... whether it be Agatha’s remnants directly or driven by the sprawling upper anticyclonic ridge’s outflow... is expected to generally shift northeast while following the surface ridge weakness associated with the upper trough to slide from its current position over western North America. Computer models now agree that the upper vorticity currently approaching from the west coast of Mexico and upper vorticity currently over Florida will merge... which should keep wind shear high and upper outflow suppressed in the Bay of Campeche such that the supportive upper anticyclonic ridge and broad low pressure is likely to thrive further ... over the Yucatan peninsula and western Caribbean Sea. Since the previous outlook’s forecast track showed this scenario... the updated one in the outlook below is unchanged. I assign 10% peak odds of tropical cyclone formation over the next five days... lower than the NHC’s 30% (as of this writing)... as I see wind shear from the aforementioned upper vorticity and land interaction with the Yucatan being strong negative factors over the next five days. The 96-hour forecast point... located on the west edge of the Yucatan... has odds lowered from 10% to 0% in this update as higher westerly shear shown in today’s 12Z GFS model run would prevent the formation of offshore thunderstorms bands west of the Yucatan that would be needed for tropical cyclone development at this location. Higher development odds may be possible in future updates once this system moves beyond the Yucatan peninsula and into the western or northwestern Caribbean.... assuming wind shear does not stay too high. Regardless of tropical cyclone development or not... will be watching for the formation of prolonged rainfall across southeastern Mexico... Belize... western Central America... and western Cuba in the days ahead.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (1800Z May 30)... 0% chance of tropical cyclone formation (southwestern Oaxaca near 16.5N-96.5W)
IOH 48 Hr Outlook (1800Z May 31)... 0% chance of tropical cyclone formation (Oaxaca/Veracruz border near 17.5N-94.5W)
IOH 72 Hr Outlook (1800Z Jun 1)... 10% chance of tropical cyclone formation (southeastern Bay of Campeche near 19.5N-92W)
IOH 96 Hr Outlook (1800Z Jun 2)... 0% chance of tropical cyclone formation (western Yucatan peninsula near 20N-90.2W)
IOH 120 Hr Outlook (1800Z Jun 3)... 10% chance of tropical cyclone formation (east coast of Yucatan peninsula near 20N-87.5W)
AREA OF INTEREST 5...Warm core upper ridging across the central United States is currently amplifying due to warm surface southerly flow ahead of a western United States frontal system (with the frontal system supported by upper divergence on the east side of a major upper trough in the region). This upper ridging has cut-off the south part of the current northwest Atlantic upper trough... with the cut-off upper vorticity currently and to be generally stationary over the Florida peninsula in the near term. The eastern divergence zone of the upper vorticity may support the formation of a subtropical or tropical disturbance... with the GFS over the last several days consistently forecasting possible tropical development out of this setup. Over the next five days... the best window for tropical development appears to be on days 3 and 4 once the cold core upper vorticity and associated shear weakens while remaining cut-off from high-latitude cold air. I have low 10% odds of tropical cyclone formation during this timeframe as the GFS remains the only model that shows development... and wind shear may remain elevated at days 4 and 5 as upper westerly flow increases with the eventual approach of the major upper trough currently over western North America. By day 5 the westerly flow ahead of the upper trough will have carried this system east-northeast into water temps below 26 deg C... and so I drop development odds to 0%
Regarding impact to land areas... increased rainfall may develop over the western Bahamas over the next 48 hours (2 days) regardless of tropical cyclone formation or not.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (1800Z May 30)...0% chance of tropical cyclone formation (east coast of Florida near 27N-80.5W)
IOH 48 Hr Outlook (1800Z May 31)...0% chance of tropical cyclone formation (offshore of the Florida east coast near 28N-79W)
IOH 72 Hr Outlook (1800Z Jun 1)...5% chance of tropical cyclone formation (western Atlantic near 28N-76W)
IOH 96 Hr Outlook (1800Z Jun 2)...10% chance of tropical cyclone formation (western Atlantic near 29N-75W)
IOH 120 Hr Outlook (1800Z Jun 3)...0% chance of tropical cyclone formation (western Atlantic near 30.5N-70W)
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/)
0000Z CMC Model Run...
**For area of interest #4... eastern Pacific Hurricane Agatha makes landfall in Mexico over southwestern Oaxaca province at 42 hours... at 84 hours a broad low pressure area containing the remnants of Agatha becomes defined inland over the Oaxaca/Veracruz border... through 144 hours the broad low pressure area moves east-northeast across the Yucatan peninsula and emerges in the waters between the peninsula and west tip of Cuba (however not as a tropical cyclone due to a SW-NE elongated structure)
**For area of interest #5... no development shown
0000Z ECMWF Model Run...
**For area of interest #4...eastern Pacific Hurricane Agatha makes landfall in Mexico over southwestern Oaxaca province at 48 hours... at 96 hours a broad low pressure area containing the remnants of Agatha becomes defined on the Bay of Campeche coast of Mexico... through 144 hours the broad low pressure area moves east into the Yucatan peninsula
**For area of interest #5... no development shown
1200Z GFS Model Run...
**For area of interest #4... eastern Pacific Hurricane Agatha makes landfall in Mexico over southwestern Oaxaca province at 30 hours... through 78 hours a broad low pressure area containing the remnants of Agatha becomes elongated NW-SE spanning from the Bay of Campeche to western Central America... through 144 hours the broad low pressure lifts northward into the western Caribbean while featuring multiple centers
**For area of interest #5... Through 96 hours the cut-off upper vorticity currently over the NE Gulf of Mexico and Florida drifts east to a location just north of the Bahamas at which time the eastern divergence zone of the vorticity produces a weak surface low just NE of the western Bahamas... through 120 hours the upper vorticity and surface low move east-northeast with the surface low reaching 30.5N-70W
1200Z NAVGEM Model Run...
**For area of interest #4... eastern Pacific Hurricane Agatha makes landfall in Mexico over southwestern Oaxaca province at 36 hours... through 60 hours a broad low pressure area containing the remnants of Agatha becomes elongated NW-SE spanning from southeastern Mexico to western Honduras... NW end of the elongated circulation lifts north into the Bay of Campeche and becomes a tropical cyclone near 19.5N-95W by 90 hours... through 120 hours tropical cyclone orbits south into SE Mexico while steered by the remainder of the elongated circulation.
**For area of interest #5...no development shown