Talking the Tropics With Mike: Potential for Michael to develop near Southern Gulf

Tropical storm WATCH & WARNING: Yucatan & W. Cuba

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Eye on the Caribbean & Gulf of Mexico - potential development of tropical cyclone "Michael" (not Buresh!)..........

Given current forecast path - SUBJECT TO SOME CHANGES - to between Mobile, Al. & the Big Bend of Fl. centered - perhaps - on the Panhandle, local impacts for Jacksonville, NE Fl. & SE Ga. are as follows:

* heavy rain in multiple bands from Mon. through Thu. with the potential for 2-4" of rain, more in some spots

* breezy winds - combination of what should become "Michael" to the west & moderately strong high pressure to the north will result in brisk winds out of the SE increasing each day Mon. - Thu. averaging 15-25 mph with gusts 30+ mph

* isolated waterspouts &/or tornadoes, especially later Tue. through Thu.

* high rip current risk at area beaches

*** More significant impacts for the Fl. Big Bend, Panhandle & coastal Alabama, perhaps Mississippi.  Remember the "cone of uncertainty" is simply & only forecast error & has nothing to do with potential damage.  Do not get too caught up in where the center might be going.

Clusters & bands of strong convection persist over the Caribbean & stretch east all the way to the SW Atlantic.  Low pressure is slowly becoming more organized & well defined near the coast of Belize & the Yucatan Peninsula.  There is a good deal of mid & upper level shear at the moment. Tropical development over the Southern Gulf &/or NW Caribbean appears probable within the next few days but the end result is still - as one would expect at this early juncture - not certain. Hurricane hunter aircraft is schedule to check out the disturbance Sunday afternoon.

Long range global forecast models have at times "lost" this system.  I would expect models to become more consistent in developing this potential tropical cyclone in the coming days, & that has appeared to become the case since late Fri./early Sat.  There is a lot of low pressure over a wide area from the Caribbean through the Gulf which may cause a delay in the "bundling" - or organization - of a single area of low pressure.  In any case.... tropical moisture will begin to surge northward next week & will likely result in an increase in rainfall - at the very least - for Jacksonville/NE Fl./SE Ga.

Spaghetti plots for the potential disturbance below (not a lot of tracks because not all forecast models are onboard for development):

Tropical wave/disturbance '91L' will be battling a good deal of shear in the coming days.  Westerly shear of 50+ mph(!) should delay overall intensification & - at least initially - result in a system heavily weighted (heaviest rain, strongest winds) on its eastern side.  Shear relaxes for a time over the Central Gulf  - & when combined with better upper level ventilation - there is concern for fairly rapid strengthening once at a more northern latitude over the Gulf.  The red lines below indicate strong shear (courtesy CIMMS):

As for movement..... the long lasting Bermuda high summer-style system over or near the Southeast U.S. will be a major player regarding the ultimate track of what could become Michael.  At the same time, a deep upper level trough will dig into the Western U.S.  Given additional "energy" that has yet to become a part of this trough + the stubbornness of the eastern ridge the last 6-7 weeks, I have a tendency to favor a more western track.  Forecast models, however, say differently bringing the system ashore near Mobile &/or the Fl. Panhandle.  The UKMET model is even farther east - closer to the Big Bend of Fl.  As for timing... Wed./Thu. is when the disturbance should make landfall.  From there, models are at odds as to whether or not the base of the western trough will extend far enough south to fully pick up the system, but it appears likely at this time that the disturbance will be absorbed by the westerlies & upper level trough so as to not hang around any one location for too long.  That part of the forecast is still highly uncertain.

So lots of question marks as one would expect at this early juncture but everyone from Florida to Louisiana should stay up to date on the latest forecasts.

Map below is upper levels (500mb) - European model - noon Tue.:

The overall pattern through the first 2+ weeks of Oct. will favor tropical development over the Atlantic Basin.  The velocity potential anomaly map below indicates expansive green lines - upward motion - spreading from the E. Pacific into the Atlantic Basin, part of a MJO (Madden-Julian Oscillation) pulse.  While tropical development could occur just about anywhere, it would appear we especially need to be vigilant of the Caribbean &/or Southwest Atlantic from approximately Oct. 8 through the 16th.

Note the secondary peak of the hurricane season in mid Oct.:


Meanwhile... Leslie continues to crawl over the Central Atlantic.  The storm's swell will affect the Florida coastline & much of the U.S. east coast through the weekend & - when combined with onshore flow - result in a high rip current risk at area beaches.  Otherwise Leslie will stay far away from any land areas as the tropical cyclone turns sharply eastward & moves from the Central into the Eastern Atlantic.


Atlantic Basin:

CIMMS satellite below shows the extent of dry air but also indicates it doesn't necessarily shut down the basin.  Note the considerable dry air between Leslie & Florida which will help to shut down widespread rainfall for Jacksonville/NE Fl./SE Ga. through Friday/Saturday.

E. Atlantic:

Mid & upper level wind shear (enemy of tropical cyclones) analysis (CIMMS). The red lines indicate strong shear:

The Atlantic Basin.... note the disturbance/tropical wave over the far E. Atlantic....


Gulf of Mexico:

Water vapor imagery (dark blue indicates dry air) - notice the dry air spinning into Leslie:

Deep oceanic heat content is seasonably high over the Caribbean, Gulf of Mexico & SW Atlantic as one would expect early in the fall....

Sea surface temp. anomalies:

SE U.S. surface map:

Surface analysis centered on the tropical Atlantic:

Surface analysis of the Gulf:


The E. Pacific remains active....

"Sergio" is a strong hurricane well offshore of Mexico, far to the south/southwest of the Baja & will turn northwest over open water through late week then veer back to the west.  Eventually the tropical cyclone - or its remnants - may affect parts of Mexico, the Baja & Southwest U.S. next week when a deep upper level trough sets up shop over the Western U.S. & accelerates Sergio to the northeast.