Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 221430
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1030 AM EDT Fri Aug 22 2014
...Dangerous Heat This Weekend...
.Near Term [Through Today]...
Forecast is on track for another hot and humid day. The TAE 12Z
sounding showed a PWAT of 1.69", only slightly less than normal for
August, but the 850mb temperature was near the 75th percentile- also
in the normal range, but on the higher end. The 1000-700 mb flow
on the sounding was light and variable, which would render a type
1 sea-breeze day. Although the atmosphere is slightly drier than
normal, there is plentiful low level moisture, so increased PoPs
slightly to a chance (30%) of showers and thunderstorms, focused
over north Florida, where we normally see the highest coverage on
regime 1 sea-breeze days. This is still a below normal chance of
precipitation for this time of year.
With all the heat and humidity and a below average chance for
relief from thunderstorms, temperatures will rise to the upper 90s
and around 100. The heat index values will be around 108-112 in
southeast Alabama, southwest Georgia and the eastern Florida Big
Bend, where we have a heat advisory out today. Along the Florida
Panhandle and the western half of the Big Bend, where we have an
excessive heat warning, heat index values will peak around 112-115.
We want to caution people to stay hydrated and reduce their exposure
to the heat today by staying indoors.
[Through 12Z Saturday] VFR conditions are expected to prevail
through the period. Cannot rule out an isolated thunderstorms at
ECP and TLH, but believe chances are too low to mention at this
.Prev Discussion [417 AM EDT]...
.Short Term [Tonight Through Sunday]...
High pressure will remain in place across the Mid South and
continue the heat wave into Saturday across our region. There is
some split between the guidance whether the ridge axis will shift
far enough west on Saturday to allow for better than isolated
coverage of showers and storms. The GFS/Euro suggest limited storm
coverage and a hot afternoon. Some differences also exist with
whether we`ll mix out in the afternoon and get dewpoints in the
upper 60s. There were some mid 60s dewpoints around the region on
Thursday, but model soundings by Saturday afternoon show limited
potential to mix drier air to the surface, so feel dewpoints are
likely to stay in the 70s on Saturday. Heat advisory conditions
are a certainty with the potential for excessive heat warning
criteria across the Florida Big Bend.
By Sunday, model guidance agrees that the ridge axis will shift
further westward and amplify between two troughs. With a trough
digging down the eastern seaboard, our region will be in a favored
location for late day MCS activity. Because it will probably be
late afternoon before storms get going, temperatures will still
warm into the upper 90s to near 100, and create another day of
heat advisory conditions with heat indicies in the 106 to 110
.Long Term [Sunday Night Through Friday]...
Northwesterly low-layer flow will veer to a more easterly
direction increasing boundary layer moisture, while deep layer
ridging persists. This increase in moisture will result in near
normal PoPs to start the period. By early next week there is
consensus that a front will slip into the region from the
northeast returning us to a drier than normal pattern to finish
the week. Temperature will remain closer to seasonal normals for
the entire extended range.
Generally light winds and low seas will continue through the
weekend. Winds and seas will be on the increase on Monday as the
gradient tightens between an area of high pressure across the Mid
Atlantic States and a tropical system moving east of the Bahamas.
Cautionary conditions are possible by Tuesday.
With plenty of heat and high humidity, no Red Flag conditions are
expected anytime in the near future.
Very little rainfall is expected over the next few days and river
levels will remain well below action stage. In fact, the
Apalachicola River is forecast to remain in low flow levels into
.Preliminary Point Temps/PoPs...
Tallahassee 102 75 100 77 99 / 30 10 20 20 40
Panama City 96 80 96 81 96 / 30 10 20 10 20
Dothan 101 76 101 76 100 / 20 10 10 10 40
Albany 102 76 101 76 99 / 20 10 10 10 50
Valdosta 103 75 102 75 98 / 30 10 20 20 50
Cross City 99 76 98 77 96 / 30 10 20 20 40
Apalachicola 95 80 94 81 94 / 30 10 20 10 20
FL...Heat Advisory until 8 PM EDT this evening for Coastal Dixie-
Coastal Jefferson-Coastal Taylor-Inland Dixie-Inland
Heat Advisory from 11 AM EDT /10 AM CDT/ to 8 PM EDT /7 PM CDT/
Saturday for Calhoun-Central Walton-Coastal Bay-Coastal
Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson-
Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay-
Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson-
Inland Taylor-Inland Wakulla-Inland Walton-Jackson-
Excessive Heat Warning until 8 PM EDT /7 PM CDT/ this evening
for Calhoun-Central Walton-Coastal Bay-Coastal Franklin-
Coastal Gulf-Coastal Wakulla-Gadsden-Holmes-Inland Bay-
Inland Franklin-Inland Gulf-Inland Wakulla-Inland Walton-
GA...Heat Advisory until 8 PM EDT this evening for Baker-Ben Hill-
Heat Advisory from 11 AM to 8 PM EDT Saturday for Baker-Ben Hill-
AL...Heat Advisory until 7 PM CDT this evening for Coffee-Dale-Geneva-
Heat Advisory from 10 AM to 7 PM CDT Saturday for Coffee-Dale-