Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL
FXUS62 KTBW 212341
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
741 PM EDT Fri Oct 21 2016
The advertised cold front is making steady progress southward
through the northern Florida peninsula this mid-evening...and will
complete its journey through the region overnight. A much drier
airmass is already being observed to our north behind this
front...and this drier air will slowly filter in through the
overnight and into Saturday morning. Very pleasant sensible weather
will be around for the duration of the weekend with low dewpoints.
Only concerns will be with some rough conditions over the coastal
waters overnight into Saturday morning behind the front. Small
craft advisories are up for all the coastal waters with the
exception of Tampa Bay and Charlotte Harbor. These Bays and
Harbors are forecast to experience cautionary level winds through
early Saturday morning. The is also some potential for an enhanced
rip current risk along area beaches for part of the day on
Saturday as the swell generated by the NW flow overnight arrives
along the Florida west coast.
Cold front will exit to the south of the region later this
evening with prevailing VFR conditions through much the TAF
period. Northwest winds shift north behind the front overnight and
remain out of the north through the daylight hours Saturday. Small
batch of MVFR cigs ahead of front is pivoting southward across the
Tampa Bay area and have included MVFR tempo for KPIE/KSRQ through
01Z. Also...probable smoke around the KPGD airport which earlier
dropped visibility appears to have ended. Have removed
restrictions with this TAF package in favor of prevailing VFR.
Will continue to monitor.
.Prev Discussion... /issued 248 PM EDT Fri Oct 21 2016/
.Much Cooler And Drier Conditions For The Weekend...
.Hazardous Boating Conditions Through Saturday...
Well advertised and anticipated dry cold front now moving over
the FL Peninsula this afternoon to exit the forecast area later
Upper longwave trough axis over the region this afternoon to move
to the eastern seaboard tonight and into the W Atlantic Saturday
with very dry NW mid to upper flow. Model soundings showing about
a quarter inch pwats area wide for Saturday.
Strong, cool and dry high pressure over the southern plains this
afternoon to build into the region tonight into Saturday advecting
dewpoints in the 40s to the FL Peninsula. Expect temps to fall
quickly this evening to below seasonal norms, bottoming out with
overnight lows into upper 40s across the Nature Coast, lower to
mid 50s central interior, and upper 50s to lower 60s south and
along the coast by morning.
For Saturday, expect pleasantly cool FL autumnal conditions with
sunny skies and temps in the lower 70s north, and mid to upper
70s central and south.
Mid/Long Term (Saturday Night - Friday)...
A highly amplified upper level pattern continues over the CONUS for
the start of the mid/long term period. An upper low sits over New
England with deep troughing extending off the eastern seaboard.
High pressure ridging extends from the western Gulf of Mexico
northward through the central U.S. This pattern will slowly shift
east through the weekend. By Monday, the parent upper low sits over
Quebec and high pressure ridging has moved into the central Gulf of
Mexico and extends over the southeast U.S. This pattern will
continue until next Thursday when another trough moves north of the
area. GFS develops a closed low in the base of this trough and holds
it in the Gulf of Mexico toward the end of the week, while ECMWF
keeps it as an open trough.
On the surface, an area of low pressure will be located over New
England and extends a cold front through the western Atlantic, over
the Bahamas and then south of Florida. Over the southeast U.S., a
broad area of surface high pressure has set up over the area. The
gradient between these two features will produce gusty north
northeast winds around 15 knots across the coastal waters. The
gradient slackens by Monday morning allowing for the winds to veer
to the northeast and decrease to around 10-15 knots.
The coolest temperatures of the season can be expected on Saturday
and Sunday night as cool dry air filters in behind the front.
Daytime highs will only reach the 70s region wide with overnight
lows in the 50s inland and low 60s near the coast. High pressure
will park over the southeast U.S. most of next week allowing for the
winds to veer to the east northeast. With the east northeast winds,
a slight chance of showers will be possible each day beginning
Wednesday as they develop over the east coast and move westward
through the afternoon. This will also bring in more warm, closer to
seasonal temperatures by Wednesday through the end of next week.
Hazardous boating conditions over the waters as strong high
pressure building into the region brings breezy NW winds and
increasing seas later this afternoon through Saturday. Small
craft headlines for the northern Gulf waters this afternoon
expanding across all waters by this evening. Inland waters,
including Tampa Bay and Charlotte Harbor, will have exercise
caution conditions and headlines this evening into Saturday.
High pressure remains N of the area and shifts eastward into the
W Atlantic with NE-E winds gradually diminishing and seas slow to
subside Sunday into early next week.
Strong High pressure to bring cool and very dry airmass into the
area this weekend with durations of min RHs in the lower 30%
range in Levy County and mid 30s elsewhere, but ERCs remain low
to prevent significant fire wx concerns.
.Preliminary Point Temps/PoPs...
TPA 59 76 55 79 / 0 0 0 0
FMY 62 79 56 80 / 0 0 0 0
GIF 58 77 53 79 / 0 0 0 0
SRQ 62 76 56 79 / 0 0 0 0
BKV 52 75 46 79 / 0 0 0 0
SPG 64 75 60 78 / 0 0 0 0
FL...Beach Hazards Statement through Monday evening for Coastal
Gulf waters...Small Craft Advisory until 11 AM EDT Saturday for Coastal
waters from Bonita Beach to Englewood FL out 20 NM-
Coastal waters from Englewood to Tarpon Springs FL
out 20 NM-Waters from Bonita Beach to Englewood FL
out 20 to 60 NM-Waters from Englewood to Tarpon
Springs FL out 20 to 60 NM.
Small Craft Advisory until 11 AM EDT Saturday for Coastal
waters from Tarpon Springs to Suwannee River FL out
20 NM-Waters from Tarpon Springs to Suwannee River FL
out 20 to 60 NM.