Low pressure to move over the Gulf & impact Jacksonville west to New Orleans

May 24, 2018 — The "Buresh Bottom Line": Always be prepared!..... City of Jacksonville Preparedness Guide... Georgia Hurricane Guide.

Low pressure over the Yucatan Peninsula will slowly move northward over the Gulf of Mexico Friday into Saturday possibly acquiring subtropical or even full tropical characteristics in the process. It appears the most probable "landfall" is from the Fl. Panhandle to New Orleans. Given my expected track & intensity (relatively weak)... the impacts for Jacksonville / NE Fl. / SE Ga. are as follows - in order of magnitude:

* heavy rain - rainfall will average 2-4" Sat. - Mon. but locally more causing some localized flooding

* rip currents at area beaches. A broad & persistent onshore flow out of the southeast will cause a moderate to high rip current risk through the holiday weekend. Never swim & surf alone & always as close to lifeguard as possible.

* gusty winds of 15-20 mph with local much higher brief gusts - 40-50 mph - with any strong rain bands or associated with any stronger thunderstorms

* isolated waterspouts or tornadoes - higher tornado threat to the west

If traveling west along the I-10 corridor through the Panhandle to Mobile, Biloxi & New Orleans, flooding rain will be the primary threat along with rip currents at beach locations... gusty winds... & a few tornadoes.

May tropical cyclones have occurred 4 times in the last 5 years:

2016 (1 - Bonnie)... 2015 (1 - Ana)... 2012 (2 - Alberto & Beryl).

The list of names repeats every 6 years, & we could have another early "Alberto" this year.

On an interesting historical note - only 4 tropical or subtropical cyclones have developed over the Gulf of Mexico since 1851 during the month of May. Only 1 of those storms has been during the satellite era of the early 1960s - on May 22nd, 1976.

The area to watch is the West & Northwest Caribbean as a poorly organized area of low pressure sits over the Eastern Yucatan Peninsula. The system will drift to the north with a surface low gradually developing over the Central &/or Eastern Gulf of Mexico.

A combination of strong shear out of the west... dry air over the Western Gulf.... & marginal sea surface temps. should all add up to a system that struggles & generally remains weak & heavily weighted on the east side which is typical of early season tropical disturbances. Shear from the west & southwest will remain significant keeping the heavier rain & gusty winds over the eastern circulation. A possible landfall will be between New Orleans and the Florida Panhandle sometime over the weekend.

The screaming message with this system will be heavy rain potential from Jacksonville & especially west along the I-10 corridor all the way to New Orleans. The more west you go from Jacksonville, the stronger the impacts: gusty winds, rough seas/surf, rip currents & heavy rain.

Water vapor imagery shows a lot of dry air over the Western Gulf of Mexico - another obstacle for any strong development as the disturbance moves north over the Gulf....

Spaghetti plots from various forecast models:

Deep oceanic heat content is typically lacking in May & this year is no different:

Sea surface temp. anomalies (a little cool either side of Fl.):

Mid & upper level wind shear (enemy of tropical cyclones) analysis (CIMMS). Notice the red lines across the gulf indicating strong shear which will likely limit just how strong the Gulf disturbance will become & keep the disturbance's heavy rain & what wind might develop over the eastern part of the low level circulation. Shear will be less significant over the far Northern Gulf but the water is cooler & the system will be nearing land.