Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 260652
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
252 AM EDT Sat Jul 26 2014
.Near Term [Through Tonight]...
Similar to the last two days, the forecast area remains sandwiched
between two upper level ridges with little in the way of synoptic
scale flow. This will make the sea breeze circulation the main
driver for convection once again today. One subtle change for today
is that the 1000-700 mb mean wind is expected to have more of a
westerly component instead of southwest like the last couple of
days. This may act to shift the main axis of scattered afternoon
convection a county or two southward with the highest coverage
expected to be across Florida. The CAM ensemble also forecasts mean
SBCAPE values this afternoon to be in the 2500-2700 j/kg range,
which is a little higher than it was forecasting for yesterday. The
00z NAM also forecasts the sfc to mid level delta thetae values to
be rather high around 38K across portions of the Florida panhandle,
although the 00z GFS and older 12z Euro run are not that high. Given
this information, it would not be surprising to see a few of the
storms become stronger today than in recent days, although the
probability of severe storms still seems rather low overall for this
afternoon (~5% or less within 25 miles of a point). Afternoon high
temperatures may actually be warmer across the northern counties
than the southern counties this afternoon due to less of a chance of
afternoon convection across the north.
.Short Term [Tonight Through Monday]...
For Sunday, the forecast area will remain in a col region between
upper ridges to east and west, and a trough to the north. The
seabreeze will continue to provide the primary forcing. However,
with the low-level flow generally out of the west and a slight
decrease in deep layer moisture, expect coverage to be lower than
on Saturday. With less convection and clouds, temperatures will be
able to rise into the mid to upper 90s, especially across interior
areas. With dewpoints holding in the lower to mid 70s, this will
likely push apparent temperatures to near 105 Sunday afternoon.
By Monday, the eastern U.S. trough is forecast to amplify and
drive a cold front southward towards the Gulf Coast. Expect to see
convection focus along the front across central Alabama/Georgia
during the early to mid afternoon, with the activity pushing south
into Florida by late afternoon.
.Long Term [Monday night Through Saturday]...
Model guidance is in reasonably good agreement that the pattern
across the Eastern CONUS will amplify considerably at the start of
the period as a large trough moves through the Ohio Valley to the
Mid Atlantic States. For several runs now, the models have all
indicated the surface cold front making it through most if not all
of our forecast area by Tuesday. Thus, expect a couple of days of
below normal temps with little or no rain chances. The bulk of the
colder air should remain confined in the Tennessee Valley and
areas to the north though Wednesday and Thursday morning lows will
drop into the 60s across Srn Alabama/Georgia.
By Thursday, the pattern stalls or even retrogrades slightly with
the 500 mb trough axis aligned from the Southern Appalachians
through our forecast area. As deep layer moisture begins to
increase on Thursday, rain chances will increase. Afternoon
temperatures will still remain below normal through this portion
of the long term period due to expected cloud cover, though
overnight lows will return to seasonal norms.
[Through 06Z Sunday] There is a possibility of brief and patchy
fog with MVFR vsbys after 09z at all sites. VFR will return
shortly after daybreak with scattered convection developing. VCTS
is included in all of the TAFs except for ABY and DHN as most of
the convection this afternoon is expected to be south of those
locations. TLH has the highest probability (around 50%) of seeing
convection today out of all of the TAF sites.
With the subtropical ridge stationed south of the waters, westerly
to southwesterly flow will continue through early next week. As a
front approaches the Gulf Coast early in the week, winds may
approach exercise caution levels Monday into Tuesday.
Red flag conditions are not expected over the next several days,
although high dispersion values are expected Sunday afternoon
across the inland Florida big bend.
Afternoon sea breezethunderstorms are expected, however heavy
rain will be localized and should not have any impact on area
.Preliminary Point Temps/PoPs...
Tallahassee 93 74 96 76 96 / 50 30 30 20 40
Panama City 89 78 91 79 90 / 50 20 40 20 30
Dothan 93 75 97 76 95 / 20 20 20 20 50
Albany 96 75 97 76 95 / 20 20 20 20 50
Valdosta 95 73 96 76 95 / 40 30 30 20 40
Cross City 91 73 94 74 93 / 40 20 50 20 20
Apalachicola 90 77 90 79 90 / 40 20 40 20 20