"Karen" In the Central Gulf.......
FOR THE FIRST COAST:
- given the forecast thinking/reasoning (see below), local impacts will -- generally -- be relatively minor
-- Sat. is fine....showers & scattered t'storms will increase Sunday through Sun. night, but it's not looking like a washout
-- could be a very isolated threat for tornadoes favoring western parts of the viewing area (Lake City to Waycross)
-- some heavy rain but speed of the system + a track to the west/northwest of Jax should limit the overall amounts -- perhaps an average of a half inch to an inch, locally 1-2" especially west & northwest of Jax.
-- breezy Sunday-Sun. night & to some degree Mon. but not overly strong averaging 15-25 mph.
-- somewhat rough seas & surf Sunday-Mon. but again relatively minor. An offshore component to the winds by Mon. will make for happy surfers(!).
Sea surface analysis below. The numbers show the wave heights with the highest numbers closer to "Karen", of course. Higher waves/rough seas & surf & a high rip current risk will reach the Fl. Panhandle coast by late Fri. & especially over the weekend. Wave heights will not be significant for the First Coast.
Satellite imagery shows a struggling "Karen"
thanks to moderate west/southwest shear. The center is clearly displaced to the west of the strong convection. The track has generally been a little west of earlier forecasts, but the end results should be similar to previous expectations. The central pressure has been slowly rising & it's possible that "Karen" will become a very minimal tropical storm before conditions improve some as the storm approaches the Gulf Coast. I even question whether or not "Karen" will be able to truly reorganize & strengthen given its current poorly organized state on satellite imagery.
The storm is being hammered by some of the strongest wind shear it will encounter. The shear actually should relax some by Fri. night into Sat. The question becomes whether or not the storm can reorganize given the messy appearance on satellite imagery + the relatively short time over warm water Sat.-early Sun. before landfall. Water temps. are more than warm enough to support a tropical cyclone, but the shear as well as dry air will be something "Karen" has to shake off: (1)
very dry mid & upper level air (as can be seen on the water vapor images below - the black & rust color) over Mexico & virtually all of the western half of the Gulf of Mexico extending north into the Southern U.S. This dry air may ultimately be the most significant hurdle for "Karen" to overcome as the dry air will remain adjacent to the storm all the way through landfall.(2)
the moderate to quite strong shear over the Gulf will abate some through Sat. night before increasing again Sun. as an upper level trough approaches. So we'll have to watch the system carefully over the weekend to see if the lighter shear allows for some organization.In addition...
as the upper level trough moves into the Eastern U.S., there might be some "ventilation" of Karen upon approach to the Gulf Coast which could compensate for the increasing shear & dry air, thereby at least maintaining the storm or even allowing for some increase. It will not take long for "Karen" to transition to an extratropical low pressure area moving northeast along a cold front.
The timing & how far south this upper trough digs will be the main driver for the track of "Karen". A weak & transient upper level ridge will build north & northeast of the storm through Sat. over Georgia & Northeast Fl. As the trough approaches, the ridge will collapse paving the way for the northeast acceleration of "Karen" Sun.-Mon. The system will then become attached to a cold front & absorbed by the upper trough over the Eastern U.S. The timing -- landfall -- of "Karen" has generally slowed which is no surprise since the upper level trough is strong & still deepening. In such a scenario, a slower evolution of weather systems usually evolves until the trough has completed the deepening process.
The GFS forecast model remains the strongest with "Karen" forecasting at least a moderately strong tropical storm moving inland near the Big Bend later Sunday. This is a departure to the east & much slower than earlier model runs. The European forecast model continues to be weaker & farther west + a little earlier. Overall....these 2 models -- which I favor to forecast the tropics with -- along with most of the other global forecast models have come into relatively decent agreement on a restrengthening -- to some degree -- system moving ashore. But since "Karen" is weak, a more westward solution initially is the most likely scenario.
So.... I favor "Karen" moving to the Gulf Coast somewhere between approximately
Pascagoula & Apalachicola about
Sunday, perhaps as late as Sun. night. BUT there could be some interaction with extreme Southeast Louisiana as early as late Sat./Sat. night then the center would hug the Gulf Coast or hang just offshore while moving east/northeast before turning more sharply northeast upon feeling the effects of the upper trough/surface cold front. We'll have to watch the recent eastward trend for the "end game" as a move inland closer to the Big Bend will be possible but for this to happen, there need to be a very sharp eastward turn.
If traveling this weekend west to the Fl. Panhandle &/or coastal Mississippi/Alabama, stay up to date on "Karen". Heavy rain & gusty winds....& possibly isolated tornadoes.... will be most significant from about the Fl. Big Bend across the Panhandle to as far west as near New Orleans. And, of course, remember that the ultimate track & intensity is subject to change(!). There will also be a corridor of potentially enhanced heavy rain & isolated tornadoes across Georgia into the Carolina's near & just east & south of the track of "Karen" or its remnants.
Click ** here
** for buoy reports from the Gulf of Mexico.
The image below shows the moderate to strong -- 20-30(+) knots -- shifting over the Eastern Gulf of Mexico.
Water vapor satellite images below showing the vast area of very dry air in close proximity to "Karen":
Model plots + radar imagery (with projected track of "Karen") below courtesy S. Fl. Water Management District:
The last advisory on "Jerry" was issued late Thu. as the system became extratropical over the Northeast Atlantic.
Tropical waves continue to decrease as they move off the coast of Africa. This late in the season, development is not common so deep in the tropics.