NEAR TERM [Through Tonight]...
The 17 UTC regional surface analysis showed a weak, quasi-stationary front from central FL to just off of the LA coast. There was a high pressure ridge along the Piedmont, and a weak low pressure system centered about 150 miles south of Destin. This low did not appear to be "attached" to a frontal zone, which is unusual for this time of year. It was translating northwestward, but recent buoy obs suggest that pressures have been rising and that there was no longer a closed isobar around the low, even though the vort max was clearly visible in the low-mid clouds on a visible satellite loop. There
were scattered showers associated with this feature affecting Dixie
County and the adjacent coastal waters.
The ECMWF appeared to have the best initial handle on this system,
so we tended to lean more toward its solution for the first part of this forecast. The highest PoP will be in the 30-40% range from the Gulf Coast southward, with 20% or less PoP elsewhere this afternoon and overnight. The combination of non-zero wind speeds and
increasing moisture (and clouds) will keep temperatures well above
climo tonight- in the mid 60s.
SHORT TERM [Sunday Through Monday Night]...
The disturbance in the Gulf of Mexico will continue to lift northward helping to increase moisture across the region. Overall forcing is limited, at least Sunday morning through early afternoon, so rain chances are only around 30 percent.
Thereafter, a cold front will begin to approach the forecast area.
Model guidance has continued to indicate that the bulk of the forcing
along the cold front will remain well to the north of the forecast area.
There is a notable difference in guidance pop values for Sunday night through Monday, and with the weakening trend noted in the models and weak forcing, lowered the inherited pop forecast slightly through Monday.
The cold front should clear through the region on Monday night with much drier air arriving by daybreak on Tuesday.
LONG TERM [Tuesday through Saturday]...
At the start of the period, a frontal zone should be located across Central Florida with cool high pressure across the Tennessee Valley creating fair weather through Wednesday.
As this high pressure area moves northeast into the Western Atlantic by Thursday, a moistening trend will begin ahead of the next system.
Confidence decreases in the forecast by Friday as the models have
difficulty with the evolution of the system for the weekend.
While the overall trend is for a frontal passage and arrival of much
cooler air toward the tail end of the period, the models differ
considerably in how we end up at that point by Saturday/Sunday.
Given the consistency, stayed closer to a slower solution offered
by the 16/00z Euro.
AVIATION [Through 18z Sunday]...
Other than patchy MVFR cigs this afternoon, we expect prevailing
VFR conditions through this evening.
While the majority of numerical guidance forecasts areas of low cigs and/or fog tonight, there is disagreement on exactly where the best chances for IFR (or worse) conditions will be.
The weak low pressure system in the Gulf of Mexico (accompanied by a mid level cloud deck) may further complicate the forecast.
We used a blend of the guidance and persistence, and are forecasting prevailing low-end MVFR cigs/vis for our FL terminals, and IFR cigs/vis elsewhere overnight through late Sunday morning.
Conditions will improve to MVFR cigs (VFR vis) by Sunday afternoon.
Small craft advisory conditions continue over the far offshore coastal legs this afternoon as an area of disturbed weather lifts slowly northwestward.
This system should slowly weaken and loosen the pressure gradient resulting in weaker winds through Monday.
After the cold front clears the marine area on Monday night, stronger winds at least at cautionary levels will return through the middle of the upcoming week.
Red Flag conditions are unlikely through at least Monday afternoon.
Rainfall amounts will not be significant over the next few days, and thus have little or no impact on area rivers.
PRELIMINARY POINT TEMPS/POPS...
Tallahassee 65 79 67 79 49 / 20 30 50 50 10
Panama City 67 76 68 75 51 / 30 30 50 50 10
Dothan 64 79 65 78 46 / 10 30 60 40 10
Albany 63 80 65 78 46 / 10 30 60 40 10
Valdosta 63 82 66 80 50 / 10 30 50 50 10
Cross City 65 82 66 77 53 / 40 30 40 50 10
Apalachicola 68 75 67 74 54 / 40 30 50 50 10
GM...SMALL CRAFT ADVISORY until 7 AM EST Sunday from Destin to the Suwannee River between 20 and 60 nautical miles.