Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus62 ktbw 191845 

Area forecast discussion
National Weather Service Tampa Bay Ruskin Florida
245 PM EDT Thu Oct 19 2017

Short term (remainder of today through friday)...
aloft - troughiness over and right off the eastern sea board shifts
out over the Atlantic Fri as a ridge from the central Gulf of Mexico
northward through the Mississippi Valley slides east...reaching the
southeastern states Fri afternoon. Surface - high pressure centered
in the southern Appalachian Mountains tracks into the central
Appalachians Fri...dominating much of the Gulf region as it does.
The frontal boundary from yesterday now resides along the Florida
Keys and through the Bahamas.

The 1000-700 mb northeast flow of this afternoon becomes east-
northeast by late Fri and spreads slightly deep moisture across the
area. Precipitable water values of 1.0 to 1.5 inches...north to
becomes around 1.5 inches area wide Sat with some swaths up to 1.7
inches in the far southeast and south. This afternoon will be
similar to yesterday with some clouds and low topped showers
drifting into the interior from east...and perhaps even reaching
Gulf coastal counties but with limited coverage. Showers will end
around sunset with partly cloudy skies...with a few patches of low
cloudiness around. Overnight winds will be strong enough to preclude
any widespread fog. Although some patchy ground fog can be expected
in the fog favoring locations. While moisture increases for Fri the
upper ridge right over head will counteract this. Localized
cloudiness and isolated to scattered showers will again drift into
the area from the East Coast during the afternoon. Thanks to the
upper ridge temperatures will run above perhaps 3 to 6

Long term (friday night-thursday)...
high pressure centered along eastern Continental U.S. To continue easterly low
level flow with a 10-30% chance of Atlantic showers through the
weekend. Temperatures to be about 5 degrees above normal but no
record highs expected.

First real cold front of the season to move through the Mississippi
Valley Saturday. Low level winds across Florida turn to the
southeast as high pressure moves into the Atlantic. Rain chance GOES
up Sunday and Monday afternoons in advance of the front. Best chance
of rain along front Monday night and Tuesday, then dry for rest of
week. High temperatures to be 5 to 10 degrees below normal Wednesday
and Thursday.


19/18z-20/18z. VFR with mainly few-scattered clouds although occasional broken MVFR
ceilings may occur this afternoon. Overnight winds should preclude any
br/fog but there may be low stratus...capped at scattered. Northeasterly
winds continue...gusty at times this afternoon.


hazardous boating conditions are expected tonight and most likely
again for the next of of nights as a tight pressure gradient results
nocturnal surges reaching caution/advisory speeds. The high begins
to move away during the weekend with a relaxing gradient into early
next week. However...a cold front coming in from the west will
increase winds and the chances of thunderstorms.


Fire weather...
northeasterly becoming southeasterly flow through the weekend will
continue to spread Atlantic moisture over the area...with isolated
to scattered rain chances and humidities above critical levels. A
cold front approaches from the west early next week with increased
showers and thunderstorms. Drier air behind the front may lower
humidities but they are expected to remain above critical levels.


Preliminary point temps/pops...
tpa 73 88 73 88 / 0 10 0 20
fmy 73 88 73 88 / 10 20 10 40
gif 71 87 71 86 / 10 20 10 10
srq 72 89 72 86 / 0 10 0 20
bkv 69 88 69 88 / 0 10 0 10
spg 73 86 73 88 / 0 10 10 20


Tbw watches/warnings/advisories...
Gulf waters...Small Craft Advisory from 7 PM this evening to 10 am EDT
Friday for coastal waters from Bonita Beach to
Englewood Florida out 20 nm-coastal waters from Englewood
to Tarpon Springs Florida out 20 nm-coastal waters from
Tarpon Springs to Suwannee River Florida out 20 nm-waters
from Bonita Beach to Englewood Florida out 20 to 60 nm-
waters from Englewood to Tarpon Springs Florida out 20 to
60 nm-waters from Tarpon Springs to Suwannee River Florida
out 20 to 60 nm.


National Weather Service Glossary of Abbreviations