Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 271351
Area Forecast Discussion
National Weather Service Tallahassee FL
951 AM EDT Thu Apr 27 2017
.NEAR TERM [Through Today]...
Broken line of thunderstorms is currently approaching the forecast
area from the west ahead of a cold front. With upper support
lifting rapidly to the northeast, only slow eastward progress of
this activity is expected through the afternoon, with the front
stalling over the far northwestern portion of the forecast area.
While low-level and deep layer shear are forecast to be marginal
by this afternoon, sufficient instability will be present to
support isolated severe storms across portions of SE Alabama and
SW Georgia. The main threats appear to be damaging wind gusts and
marginally severe hail, with the highest threat primarily north
and west of a line from Geneva to Albany.
Have left the forecast for the northwestern CWA largely unchanged.
However, with forcing becoming more limited with time, have
lowered rain chances for the southwestern half of the forecast
area, including Tallahassee and Valdosta. It seems unlikely that
these areas will see any rain today.
.PREV DISCUSSION [649 AM EDT]...
.SHORT TERM [Tonight Through Saturday]...
The aforementioned cold front will pull up and stop somewhere very
near the Tri-State intersection by this evening. At that point,
deep layer ridging will build in across the region from the south
as the shortwave continues to lift into Canada. Deep layer return
flow will force the cold front back north and west out of the
region. With cloud cover expected to be plentiful overnight, lows
will have trouble falling below 70 degrees. Highs warming into
the 90s both Friday and Saturday will set the stage for the
seabreeze circulation, though with a dry mid/upper level airmass
being advected into the region, showers and isolated storms should
remain few and far between as well as being relatively shallow.
For now, rain chances remain around 10% each afternoon.
.LONG TERM [Saturday Night Through Thursday]...
A strong shortwave will move through the Southern Plains through
Saturday night, the Mississippi Valley through Sunday night, and
across the Great Lakes region through Monday night. The associated
cold front and convection will reach our Alabama and Florida
panhandle counties around Sunday night, exiting the southeast Big
Bend sometime Monday night or early Tuesday morning. This system
is expected to be a potent severe weather producer across the Gulf
states over the weekend. The timing of the front into our region
will be an important factor as to whether severe weather would be
anticipated locally. A late night arrival on Sunday would starve
the system of much needed instability. Though if it slows down or
speeds up much, instability could be more favorable and line up
with modest lapse rates, strong low and deep layer shear, and
favorable hodographs. Stay tuned as this system draws nearer.
Tuesday and Wednesday are expected to be dry, before another
system brings rain chances to the region again by Thursday. Highs
will begin the period above average and then become closer to
normal from Monday through Thursday.
.AVIATION [Through 12Z Friday]...
MVFR-IFR cigs and gusty winds from the south continue across the
area. A line of storms across central AL will lift north as it
heads eastward, so TS are only expected near ECP, DHN, and ABY,
although isolated convection will be possible further east. Cigs
may lift briefly during the day, but are expected to fall to IFR
levels later tonight after the line of storms exit.
While sustained Advisory conditions are expected to subside by
early morning, frequent gusts over 20 knots will warrant keeping
the Advisory in place into the afternoon. Thereafter, on-and-off
Cautionary level winds should be expected through Saturday, before
another increase to Advisory conditions is expected on Sunday into
Relative humidity values will remain above critical thresholds
through the period, so no Red Flag Conditions are expected. Strong
winds from the south will cause high dispersions across the area
this afternoon, especially across southwest Georgia.
Average rainfall amounts with today`s storms are expected to be
around a half of an inch or less, with isolated amounts between
1-2" inches in stronger storms. These totals should also remain
confined along and northwest of a line from Albany through Destin.
Early indications are that average amounts with our next system
late in the weekend/early next week could range from 1-2" with
isolated higher amounts. These values appear as though they`ll
mostly be confined along and west of a line from Albany through
Tallahassee. River levels remain quite low, with ensemble guidance
not indicating any river flooding across the region over the next
7 days. Even though ensemble guidance is using the lower end of
the QPF envelope, the higher end estimates likely would not
result in much more than action stage along our most sensitive
rivers. Thus, at this time flooding is not a concern over the next
week or so.
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 86 71 90 67 90 / 10 10 10 10 10
Panama City 78 73 83 71 83 / 20 20 10 10 10
Dothan 83 71 88 68 90 / 50 30 20 0 10
Albany 87 71 89 68 91 / 40 30 20 0 10
Valdosta 87 70 92 69 92 / 10 10 10 10 10
Cross City 86 70 92 67 91 / 10 10 10 10 10
Apalachicola 81 73 83 71 83 / 10 10 10 10 10
FL...High Rip Current Risk through late tonight for Coastal Bay-
Coastal Franklin-Coastal Gulf-South Walton.
GM...Small Craft Advisory until 2 PM EDT this afternoon for Coastal
waters from Apalachicola to Destin FL out 20 NM-Waters from
Apalachicola to Destin FL from 20 to 60 NM.