Southwest Florida Weather Forecast Discussion - Tampa Bay National Weather Service

000
FXUS62 KTBW 090620
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
220 AM EDT THU SEP 9 2010

.SHORT TERM (TODAY - SATURDAY)...WE WILL STAY IN A TYPICAL
SUMMER-TIME PATTERN THROUGH SATURDAY WITH LITTLE IN THE WAY OF
SYNOPTIC SCALE FEATURES TO INFLUENCE OUR WEATHER. 500MB
TEMPERATURES STAY WITHIN A DEGREE EITHER WAY OF -5 CELSIUS WHICH
IS ON THE WARM SIDE. SURFACE RIDGE OF HIGH PRESSURE WILL BE
OVERHEAD WITH LIGHT WINDS BECOMING LOCAL SEA BREEZES EACH DAY.
PRECIPITABLE WATERS STAY MOSTLY ON THE PLUS SIDE OF 2 INCHES...
BUT THERE IS SOME INDICATION OF DRIER AIR OVER THE NATURE COAST
ON FRIDAY.
 
FOR TODAY...BEST RAIN CHANCES WILL BE OVER THE INTERIOR WHERE SEA
BREEZE CONVERGENCE SETS UP. HAVE ADDED A STRIP OF 60
POPS...NUMEROUS THUNDERSTORMS FOR THE AFTERNOON HOURS FROM POLK
COUNTY SOUTHWARD INTO INTERIOR CHARLOTTE AND LEE.
 
SOME DRIER AIR MOVES INTO OUR NORTHERN ZONES ON FRIDAY SO BEST
RAIN CHANCES WILL BE FROM HILLSBOROUGH/POLK COUNTIES SOUTH.
 
ON SATURDAY...THE LOW-LEVEL FLOW TURNS MORE EASTERLY ALTHOUGH SEA
BREEZES WILL STILL DOMINATE IN THE AFTERNOON. THIS SHOULD PUT THE
BEST RAIN CHANCES A LITTLE CLOSER TO THE COAST...ESPECIALLY SOUTH
OF TAMPA BAY.

.LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...
THE EXTENDED PERIOD WILL BEGIN WITH A STRONG SUBTROPICAL RIDGE OF
HIGH PRESSURE AT 500 MB CONTROLLING THE WEATHER. THE RIDGE AXIS
WILL RUN ROUGHLY ALONG THE GULF COAST AND ACROSS NORTH CENTRAL
FLORIDA. THIS WILL ALLOW FOR AN EASTERLY FLOW ACROSS THE AREA TO
START THE PERIOD. THE RIDGE WILL STRENGTHEN EARLY NEXT WEEK BUT
THE AXIS WILL SAG SOUTH AS 500 MB TROUGHING SWINGS THROUGH THE
GREAT LAKES AND A REINFORCING SHORTWAVE ROUNDS ITS BASE TUESDAY
AND FIRST SUPPRESSES THE RIDGE SOUTH...BUT THEN WEAKENS THE RIDGE.
HEIGHTS BEGIN TO FALL BY LATE MONDAY AND INTO TUESDAY AS THE
TROUGHING BUILD SOUTH DOWN THE EASTERN SEABOARD. INITIALLY THE
IMPACT WILL BE FOR DRIER AIR WHICH WILL ALLOW FOR LOWS TO DROP TO
NEAR CLIMATOLOGY OR SLIGHTLY BELOW...BUT HIGHS WILL REMAIN NEAR OR
ABOVE NORMAL. MEX GUIDANCE INDICATES READINGS STILL WELL INTO THE
MID 90S ACROSS THE INTERIOR...AND LOWS IN THE UPPER 60S NORTH TO
NEAR 80 ALONG THE COAST. POPS WILL REMAIN LOW IN THE EXTENDED AS
THE GENERAL FLOW SHIFTS FROM EAST TO NORTH BY EARLY NEXT WEEK.
THIS WILL KEEP A DRIER PATTERN IN PLACE AND SUPPRESS DECENT
CONVECTION TO PRIMARILY SOUTH OF THE FORECAST AREA.

&&

.AVIATION...
WEAK HIGH PRESSURE AT THE SURFACE WILL REMAIN OVER THE AREA
TODAY. THIS WILL BRING VFR CONDITIONS...AND SEA BREEZES WILL
DEVELOP AND ALLOW FOR CB AND VCTS AFTER 19Z. THIS WILL PERSIST
THROUGH 02Z AND THEN SKIES WILL CLEAR AGAIN.

&&

.MARINE...WINDS ARE CURRENTLY 5 TO 10 KNOTS WITH SEAS AROUND 1
FOOT. WITH A RIDGE OF HIGH PRESSURE REMAINING OVERHEAD...LOOK FOR
WINDS TO REMAIN 10 KNOTS OR LESS AND SEAS MAINLY 2 FEET OR LESS
THROUGH EARLY NEXT WEEK.

&&

.FIRE WEATHER...FAIR TO POOR DISPERSIONS LIKELY NEXT COUPLE OF
DAYS WITH VERY LIGHT TRANSPORT WINDS IN PLACE. OTHERWISE...NO FIRE
WEATHER HAZARDS EXPECTED.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  91  77  91  78 /  40  20  30  20 
FMY  92  76  92  77 /  50  20  50  20 
GIF  93  76  93  75 /  60  20  50  10 
SRQ  91  76  90  77 /  40  20  40  20 
BKV  93  72  93  72 /  40  20  30  10 
SPG  91  80  91  80 /  40  20  30  20 

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.

&&

$$

SHORT TERM/MARINE/FIRE WEATHER...JILLSON
LONG TERM/AVIATION...JOHNSON

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