Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 300526
Area Forecast Discussion
National Weather Service Tallahassee FL
126 AM EDT Thu Mar 30 2017
.AVIATION [Through 06Z Friday]...
There is good agreement among the latest statistical and dynamical
guidance in there being minimal fog and low clouds overnight. The
00Z KTAE sounding and recent surface obs show that the PBL dried
compared to 24 hours ago, so this forecast seems reasonable. By
late morning S winds will increase to 10 to 15 KT with gusts of 20
to 25 KT. SHRA/TSRA will move into KDHN and KECP from the west,
ahead of an approaching cold front, between 03Z and 06Z.
.PREV DISCUSSION [907 PM EDT]...
.NEAR TERM [Through Tonight]...
00 UTC surface analysis shows a frontal zone across eastern OK/TX
with thunderstorms ongoing well ahead of the front in Nrn LA/AR.
High pressure had moved a little further east of our region into
the Western Atlantic. The low level airmass continues to moisten
across our region as dewpoints this evening are generally in the
low 60s in North Florida. Primary concern overnight is with
respect to fog development. Debris cloudiness from upstream
convection over LA will move over the region tonight. This coupled
with a tighter pressure gradient should limit the overall fog
potential compared to previous mornings. Expect another mild night
with temperatures generally in the upper 50s to lower 60s.
.SHORT TERM [Thursday Through Friday Night]...
A sharp upper level trough will move eastward across the
Mississippi Valley and Central Gulf Coast regions on Thursday
before moving into our area Thursday night through Friday morning.
Ahead of this feature, deep layer moisture will increase with PWAT
values around 1.5". At the surface, a cold front will move
eastward into Alabama on Thursday night, with multiple models
depicting lines/clusters of showers and thunderstorms moving into
SE Alabama and the FL Panhandle from the evening through the
overnight hours. Some of the thunderstorms could be strong to
severe, as a robust mid-level jet could lead to effective bulk
shear values exceeding 50 kts. The instability may be a limiting
factor, although some of the latest hi-res models show CAPE
increasing to 1000-1500 J/kg near the Panhandle coast overnight.
The main threat would likely be damaging winds, although with a
decent low-level jet a tornado could not be ruled out.
Scattered showers and storms are expected to persist farther east
across the remainder of our area on Friday morning, though these
may be less intense than overnight as moisture and instability
will decrease slightly when the front moves through SW Georgia
and the Florida Big Bend. Expect showers and thunderstorms to end
across eastern portions of our area on Friday afternoon, with dry
conditions expected during the night. Thursday will be very warm
again across inland areas, with highs in the mid to upper 80s.
Upper 70s are expected along the Gulf Coast. Lows Thursday night
will range from the low-mid 60s across most of our area. Friday
will be slightly less warm as the front moves through, with highs
in the lower 80s inland / mid 70s near the coast and lows in the
mid-upper 50s on Friday night.
.LONG TERM [Saturday Through Wednesday]...
Dry and warm conditions will prevail during the weekend under an
upper level ridge, with highs reaching the mid-upper 80s each
day. More active weather is expected to return Monday as another
highly amplified upper trough approaches our area. This feature
will be associated with a sub-1000 mb surface low possibly moving
northeastward across the lower Mississippi Valley region into the
Ohio Valley region from Monday afternoon through the night. CAPE
will potentially increase to 1000-2000 J/kg across our area and a
strong mid-level jet could produce very high bulk shear values. If
this setup verifies, there would be a decent chance of strong to
severe thunderstorms across our area, with all modes of severe
weather (damaging wind, hail, and tornadoes) possible. As deep
layer moisture moves into our area (PWAT values up to 2.0"), heavy
rain is also possible with this system, especially across western
parts of our area with some models showing the potential for up
to several inches of rain. However, since this event is still
several days out, significant uncertainty remains in the track and
intensity of the system.
Drier conditions are expected on Tuesday once the low and cold
front move away from our area, but another strong system is
expected to move into the central US on Wednesday. To the
southeast of this system, southerly flow will bring increasing
instability and moisture back to our area so chances for showers
and thunderstorms are expected to increase again, especially
late Wednesday. Strong thunderstorms and areas of heavy rain also
appear possible with this system, although it is still at least a
week out and ample uncertainty remains. High temperatures will
generally remain in the lower 80s during the early and middle
portions of the week, with lows mainly in the lower 60s.
Light to moderate southeasterly winds will become southerly on
Thursday, and could increase to cautionary levels Thursday night
as a front approaches our area. Winds and seas will subside behind
the front from Friday through the weekend. A stronger system may
move into our area early next week, with advisory level conditions
possible across our marine areas on Monday.
Red flag conditions are not expected for the next several days.
There is a good chance of wetting rain Thursday night and Friday as
a cold front moves through.
Multiple systems are expected to produce showers and thunderstorms
across our area over the next several days; the first will move
through Thursday night, with additional chances on Monday and
during the middle of next week. Areas of heavy rainfall are
possible with each system, although the first one on Thursday
night does not look likely to cause flooding. Heavier rainfall is
possible with both systems next week, although since they are
several days out significant uncertainty remains with the location
and intensity of heaviest rain.
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 85 64 84 53 87 / 10 50 50 0 0
Panama City 77 67 77 59 79 / 10 70 30 0 0
Dothan 85 62 81 53 86 / 10 80 20 0 0
Albany 87 64 82 53 85 / 20 70 50 0 0
Valdosta 87 62 84 53 87 / 20 30 40 0 0
Cross City 83 62 83 53 85 / 10 20 40 0 0
Apalachicola 76 66 77 59 79 / 10 60 50 0 0