Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL
FXUS62 KTBW 270756
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
356 AM EDT Thu Apr 27 2017
.SHORT TERM (Today - Friday)...
A mid level trough will swing through the southeastern states today,
pulling a weak surface cold front through the northern Gulf of
Mexico. This front will wash out before reaching the forecast area,
but will still create somewhat breezy winds, particularly along the
coast. Without the cooling relief that the cold front would have
provided, temperatures are forecast to be significantly warmer than
they were yesterday, with highs topping out in the low to mid 90s
over the interior, and upper 80s along the coast.
On Friday, the mid level ridge will strengthen across the Florida
Peninsula, while the surface ridge generally holds in place.
Temperatures and dew points will climb another degree or two higher,
making for another hot and humid day. High temperatures are forecast
to be near record levels for late April, and a few records could
easily be tied or broken. Despite the increased low level moisture,
the ridging will keep conditions stable, and rain will be unlikely
across the area.
.LONG TERM (Friday night-Wednesday)...
Period will begin with a deep U/L trough digging near the four
corners area. The digging trough will help pump up a strong U/L
ridge over the western Atlantic and Florida with building heights
and increasing large scale subsidence over the forecast area. The U/L
ridge will hold over the Florida peninsula through early next week.
A strong U/L disturbance will lift across the southern Plains
Saturday night...to the mid Missouri valley Sunday and Sunday
night...to the western Great Lakes late Monday and Monday night. The
associated U/L trough will approach the eastern seaboard Monday
night and Tuesday...but the U/L ridge over the western Atlantic and
Florida will be difficult to supplant with quasi-zonal U/L flow
developing across the northern Gulf of Mexico and Florida along the
southern extreme of the L/W trough. Pattern change appears possible
mid to late next week as significant amplification of the L/W
pattern may occur across the CONUS with a building ridge out west
and deepening trough over the east.
At the surface, an extensive area of high pressure over the central
and western Atlantic will extend across the Florida peninsula and
eastern Gulf of Mexico Friday night through Sunday night. Increasing
deep layer subsidence associated with the building U/L ridge will
allow temperatures to run 5 to 10 degrees above climatic normals
with high temperatures in the mid/upper 80s near the coast to mid
90s inland with near record highs possible on Saturday. The surface
ridge axis will remain north of the forecast area with increasing
southerly flow over the region. A cold front, associated with the
system near the Great Lakes, will approach the forecast area on
Monday with an increasing chance of showers and possibly
thunderstorms. GFS is more aggressive pushing the cold front across
the forecast area Monday stalling across south Florida Monday night
and Tuesday. Leaning toward the ECMWF solution which does not push
the front as far south, stalling it across north Florida late Monday
and Monday night as it becomes parallel to the U/L flow. With this
solution, shower activity will decrease in areal coverage as it
approaches west central Florida due to weakening U/L support and low
level convergence which would lead to lower POPS across the forecast
Some patchy fog has developed around KPGD and is creating localized
LIFR conditions. Patches of fog may also impact other sites closer
to sunrise this morning, creating brief MVFR/IFR visibilities. Any
fog that does develop will quickly burn off after sunrise, with VFR
conditions expected to then hold through the rest of the day.
High pressure will continue to ridge from the Atlantic into the
eastern Gulf of Mexico through the weekend. A weak front washing out
over the northern Gulf today will produce a tight pressure gradient,
with cautionary headlines needed for the Gulf waters north of Tarpon
Springs this morning. Winds will increase again to around exercise
caution levels Sunday and Monday as another front moves into the
A fairly dry airmass will remain in place today and Friday, with a
couple of hours of critically low relative humidity possible,
especially over the interior. Winds will also be breezy today,
mainly along the coast where relative humidity is not expected to be
as low. Although the wind and humidity is not forecast to line up
anywhere to cause Red Flag conditions, it will be close, and isolated
locations briefly meeting Red Flag criteria is not impossible.
Moisture will gradually increase into the weekend.
.Preliminary Point Temps/PoPs...
TPA 87 72 90 74 / 0 10 10 10
FMY 89 72 92 72 / 0 10 10 0
GIF 94 70 95 72 / 0 10 10 10
SRQ 83 72 85 72 / 0 10 10 10
BKV 90 68 93 68 / 0 10 10 10
SPG 86 73 89 75 / 0 10 10 10
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...18/Fleming
MID TERM/LONG TERM/DECISION SUPPORT...13/Oglesby