• Talking the Tropics With Mike: Humberto moving away from Florida...plenty to track over the Atlantic

    By: Michael Buresh

    Updated:

    Sept. 17, 2018 - The "Buresh Bottom Line": Always be prepared!.....First Alert Hurricane Survival Guide... City of Jacksonville Preparedness Guide... Georgia Hurricane Guide.  

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    There will be no inland local impacts from Humberto but the combination of Humberto well to the east & high pressure to the north will result in a continuation of dangerous conditions at our beaches.  Rough seas & surf will only slowly subside & a very high rip current risk will continue much of this week.

    Tropical depression #9 was upgraded late Friday afternoon... to tropical storm Humberto late Fri. evening... & to a hurricane Sunday evening - while east of Florida & north of the Bahamas.  The storm continues to organize & strengthen with a broad & somewhat ragged eye. 

    Overall conditions look favorable for strengthening into Wed. & Humberto could become a Cat. 3 while turning sharply to the east/northeast & - by midweek - accelerating away from the U.S.  There look to be some impacts on Bermuda mid to late week where a tropical storm WARNING hs been issued.

    The positioning & strength of the Bermuda high over the Atlantic plus an incoming upper level trough over the Northeast U.S. is again (like Dorian) playing an important role in the track. 

    Sunday afternoon - at about 30-35,000 feet - there was a weakening trough will be over New England while the Bermuda high starts to strengthen over the Central Atlantic & the upper low over the Gulf "peels" away to the west.  This essentially leaves an alleyway over Fl. giving Humberto an "out" well to the east of Fl.  After a brief "rest" northwest of Bermuda, Humberto will resume its northeast movement while accelerating to the N. Atlantic.

    Ensemble model forecasts for Humberto show a nice shift east:

    A wider view of the Gulf/SW Atlantic shows Humberto as well as an upper low over the Gulf of Mexico that's trying to develop a surface low over the Northwest Gulf that will need to be monitored for tropical development.  T'storm activity  - though disorganized - has been persistent across the Central & now Northwest Gulf.  But time is running out for significant development as the surface low pressure will move inland over Texas by Wednesday.  Very heavy rain & flooding will plague coastal SE Texas as far inland as Houston & College Station.

    There are a couple of active tropical waves over the Central & East Atlantic that will likely develop with long term track the big question mark (of course!).  Plenty of time to watch/monitor/track & "cipher".  Most of the more reliable global forecast models - European/GFS/UKMET - are bouncing around on development not to mention the location, but the Northeast Caribbean may be faced with another named storm - "Imelda" &/or "Jerry" within this week & yet again the following week.  Regarding the first wave - '97-L' - global forecast models are generally showing a turn north in the long range implying no threat to the U.S. BUT it's very early & the steering influences will still undergo some changes leading up to the last 10 days of this month. Also of interest.... a lead wave that had been weakening has flared with some t'storms recently while moving into the Eastern Caribbean - something to keep an eye perhaps for the W. Caribbean &/or Gulf of Mexico. And there are multiple strong tropical waves moving off the coast of Africa.

     

     

    An examination of dust over the Atlantic shows generally less dust over the basin vs. past months which is fairly typical for September & the peak of the hurricane season. Much too much is made of the dust & tropical cyclones.  It's not all uncommon for tropical waves to simply "wait out" the dry air & dust organizing once the wave is clear of the dry atmosphere.

    2019 names..... "Imelda" is next on the Atlantic list (names are picked at random... repeat every 6 years... historic storms are retired (Florence & Michael last year) & Dorian is almost certain to be next:

     

    East Atlantic:

    Mid & upper level wind shear (enemy of tropical cyclones) analysis (CIMMS). The red lines indicate strong shear of which there is plenty across the Atlantic at the moment:

    The Atlantic Basin:

    Water vapor imagery (dark blue indicates dry air):

    Deep oceanic heat content:

    Sea surface temp. anomalies show a warm Gulf of Mexico, Central & Northwest Atlantic while the "Main Development Region" (MDR) remain cooler than avg.  Note the upwelling (cooler water) left behind Dorian over the Bahamas & east of Florida:

    While the MDR is cooler than avg., it's important to realize the water is still warm enough to support tropical systems....

    SE U.S. surface map:

    Surface analysis centered on the tropical Atlantic:

    Surface analysis of the Gulf:

    Caribbean:

     

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