NEAR TERM [Through Today]...
The high-resolution model forecasts of a thin line of showers and
thunderstorms developing from our western offshore waters to near
Apalachicola and NE to Madison appear to be panning out now. This
gives more credence to their solutions for the remainder of the day,
which includes a higher PoP forecast in the afternoon hours.
In the immediate near term (0-6hr), it looks like the bulk of convective
activity this morning will be focused in a similar axis, and this is
where PoPs were maximized around 30% through 18 UTC. KEVX radar has shown multiple thin boundaries overnight oriented in SW-NE fashion offshore of Bay and Gulf counties. There are a few showers forming along these boundaries now, and these will need to be monitored closely this morning as that is sometimes a precursor to some waterspout development (tends to peak around 14-16 UTC).
For the afternoon, the PoPs have been adjusted upwards.
Despite the pocket of drier mid-level air, the latest PoPs derived from the convection-allowing models show a large area of "likely" values
(60-70%) across our forecast area today.
This matches the typical sea breeze climatology for southerly flow regimes a bit more closely. We did not increase the PoPs as high as the CAM or climatology suggests, but 60% PoPs were added near the GA-FL border region westward to Lake Seminole.
MLCAPE looks to be considerably higher today, and could exceed 2000 j/kg by afternoon in some locations. When combined with maximum delta thetae values of around 30C, we will need to monitor downburst potential closely. A local downburst checklist, in addition to forecast WMSI values, suggest that we could see a few storms capable of producing damaging winds this afternoon. "Gusty winds" wording was maintained.
SHORT TERM [Tonight Through Monday]...
Afternoon convection should diminish this evening in typical diurnal fashion for this time of year.
On Sunday, rather deep tropical moisture will continue advecting northward with PWAT values around 2 inches in the area. Both the NAM and GFS also show a weak shortwave trough affecting the area.
Therefore, PoPs are in the likely range on Sunday. The 00z NAM actually has a mesolow lifting out of the Gulf in the western portions of the area, which causes the model to have favorable shear profiles for organized severe storms Sunday afternoon over the western third of the area, but this solution looks suspect at this time. It would be
climatologically unusual to get severe weather in this fashion in
June, and the GFS does not have this feature.
On Monday, deep tropical moisture remains in the area with deep
layer southerly flow, so another day of at least scattered storms
appears to be on tap. Temperatures near seasonal averages are
LONG TERM [Monday Night through Friday]...
A long wave trough will pivot southeastward across the Southeastern U.S. through Tuesday with an even sharper trough digging into the region from Thursday into Friday.
At the surface, the subtropical ridge axis will be over or just south of the marine area. However, the upper troughs will suppress this axis
further to the south with a frontal boundary stalling north of the
The second deeper trough may actually drive a cold front all the way into the forecast area on Friday.
This pattern will promote an unsettled period of weather with scattered to numerous thunderstorms developing each day.
Temperatures will be within a degree or two of seasonal norms for the most part with max temps slightly above normal on Wednesday and Thursday.
AVIATION [through 12 UTC Sunday]...
Some sporadic reductions in flight category have been occurring this
morning at all five terminals with some fog or low stratus.
However, we expect an improvement to VFR quickly as the sun rises by 13-14 UTC.
There is a bit more confidence in the progression of storms today, so TEMPO groups were added at most of the terminals for 2-3hr periods when storms are more likely. These TEMPO groups include some
25 knot gusts and low-end MVFR visibility.
A ridge of high pressure will be south of the waters for the next
This will maintain mainly light to occasionally moderate onshore flow across the region through Wednesday.
Relative humidities will remain above critical thresholds as daily
chances of showers and thunderstorms continue well into next
Although widespread heavy rainfall is not expected for the next
several days, any storms that develop through at least Monday will
be capable of producing torrential rainfall rates and localized
areas of flooding in low lying and urban areas with deep tropical
moisture in place.
PRELIMINARY POINT TEMPS/POPS...
Tallahassee 91 70 87 68 90 / 60 20 60 30 50
Panama City 86 73 85 72 87 / 30 20 60 40 40
Dothan 90 70 87 70 91 / 50 30 60 40 50
Albany 90 70 88 70 91 / 40 30 60 40 50
Valdosta 91 69 88 68 91 / 50 30 60 30 50
Cross City 88 70 88 68 89 / 30 20 60 30 50
Apalachicola 85 73 85 71 86 / 30 20 60 30 40