Weather

Talking the Tropics With Mike: T.D. #22 to “sit & spin” over the Western Gulf for days

Jacksonville, Fl. — The “Buresh Bottom Line”: Always be prepared!.....First Alert Hurricane Survival Guide... City of Jacksonville Preparedness Guide... Georgia Hurricane Guide.

STAY INFORMED: Get the * FREE * First Alert Weather app

FREE NEWS UPDATES, ALERTS: Action News Jax app for Apple | For Android

WATCH “Talking & Tracking the Tropics: The Science Behind the Season

WATCH “Preparing for the Storm

READ the First Alert Hurricane Center “Survival Guide

***** ALWAYS CHECK & RE-CHECK THE LATEST FORECAST & UPDATES! *****

TROPICS:

(1) Quick Sally recap: an area of ‘disturbed’ weather (showers & storms) that developed over the Bahamas late last week was upgraded to tropical depression #19 Fri. (11th) making landfall on the southeast coast of Fl. not far from Miami about 2am EDT Sat. then re-emerged over the warm Gulf by midday Sat. then quickly became tropical storm “Sally” Sat. afternoon. After holding steady state through early Mon., Sally strengthened into a hurricane late Mon. morning while wobbling some to the north followed by a slow approach to the Gulf Coast making landfall about 7am EDT Wed., the 16th at Gulf Shores, Alabama near the Alabama/Florida border. Sally is the 8th named storm to make a U.S. landfall this season beating the record - by Sept. 16th - of 7 in 1916. 2004 was the last time the U.S. had four hurricane landfalls (Charley, Frances, Gaston & Ivan) by Sept. 16th. In fact, Cat. 3 hurricane Ivan in ’04 made landfall very near the spot that Sally came ashore. Like most of the names this season... this is the fastest to 'S’ beating the record of “Stan” Oct. 2, 2005.

Despite moderate shear & proximity to land, Sally managed a strengthening phase Tue. night a little before landfall near the “Flora-Bama” between Mobile & Pensacola as a Cat. 2 hurricane early Wed., Sept. 16th. While winds were strong, it’s the water (rain & storm surge) that was most devastating with Sally. The remnant low pressure is developing frontal features while accelerating east/northeast over the W. Atlantic.

So the focus for heavy rain over the Lower 48 now shifts to the SE Texas coast where’s a “tropical crawler”:

(2) Tropical disturbance (90-L) over the Western Gulf of Mexico was upgraded Thu. evening to tropical depression #22. Gradual strengthening is likely & will be “Wilfred” once the depression is a tropical storm. Where exactly the storm ends up going is a really good question. First & foremost, the system should more or less sit & spin over the far Western Gulf through at least the weekend. The GFS model has consolidated on a tropical cyclone drifting west/northwest & getting to the Texas coast before becoming stationary or very slowly moving north/northeast along the coast. The European shows the low pressure generally just meandering over the Western Gulf with a slow drift to the west while strengthening. The Euro model has trended a bit more north with a stronger impact on Texas & Louisiana (vs. moving across the far Northern Gulf before moving inland). The UKMET stalls the storm over the Western Gulf before a slow north/northwest movement that would strongly threaten the Texas coast. We’re right on the crossover between when Western Gulf tropical cyclones usually move west (June/July/Aug./early Sept.) vs. moving north or east (later Sept./Oct./Nov.).

So the key will be whether or not weak troughing to the north can have any influence on t.d. #22. A weak upper level ridge of high pressure will be developing through the weekend which should help steer the system more to the west. The ridge seemingly breaks down early next week which would allow for a more northward or even northeast motion. In any case, there’s a risk - again! - to the Gulf Coast states. Still very early on this one, but t.d. #22 will be uncomfortably close to land for a number of days in a row while likely intensifying.

(3) Depression #20 formed Sat. from a westbound African tropical wave & was upgraded to “Teddy” early Mon., Sept. 14th... to a hurricane early Wed. & became a “major” (Cat. 3+) hurricane Thu. reaching a Cat. 4 by late Thu. This is the fastest to the 20th storm breaking the record of an unnamed tropical storm Oct. 4, 2005. Indications are that the Bermuda High to the north will shift more to the east & north allowing for a turn to the north over the Western Atlantic. This will be a clear miss for the Antilles.... & stays far to the east of the U.S. - reaches Jacksonville’s latitude hundreds of miles away late Sun./Sunday night - but will maintain easterly swells to the U.S. east coast - & a heightened rip current risk - into at least the upcoming weekend/early next week as Teddy will be a large & strong hurricane. There is an increasing threat to Bermuda by Monday.... & to Nova Scotia & Newfoundland by the middle of next week as Teddy bends back to the northwest over the NW Atlantic.

(4) There are at least two significant tropical waves moving west over the far Eastern Atlantic & near the coast of Africa. Either or both of these waves have the potential to develop.

(5) A stationary front will hang over the SW Atlantic into the Eastern Gulf much of next week. We’ll need to watch for any persistent clusters of t’storms/developing low pressure that might try to “go” tropical. Nothing indicated at the moment.

Atlantic Basin wave forecast for 24, 48 & 72 hours respectively (major wave action at Fl./Ga. beaches through early next week due to persistent brisk onshore flow (high pressure to the north) combined with easterly swells from distant Teddy:

September is usually the most active month of the hurricane season:



Saharan dust:

2020 names..... “Wilfred” is the last name on the Atlantic list (names are picked at random by the World Meteorological Organization... repeat every 6 years... historic storms are retired (Florence & Michael in ’18 & Dorian is certain to be retired from the ’19 list). Interesting side note: the last six of the names on the ’20 list had never been used. So it will be on to the Greek alphabet once Wilfred is used. “Alpha” is the first name, & it’ll be the first time the Greek alphabet has been used since 2005 (total of 27 named storms using 6 Greek letter names in ’05)

East Atlantic:


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

Water vapor imagery (dark blue indicates dry air):

Deep oceanic heat content is impressive:

Sea surface temp. anomalies:

SE U.S. surface map:

Surface analysis centered on the tropical Atlantic:

Surface analysis of the Gulf:

Caribbean:

Global tropical activity: