National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS62 KTBW 220112 AAA
AFDTBW

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
912 PM EDT TUE MAY 21 2013

.UPDATE...A FEW LINGERING SHOWERS HAVE DEVELOPED ACROSS POLK
COUNTY ALONG WEAK OUTFLOWS AND IN AREAS THAT DID NOT SEE MUCH AFTN
ACTIVITY. ANY SHOWERS THAT DEVELOP OVER THE GULF STREAM OVERNIGHT
ARE NOT EXPECTED TO REACH THE WRN HALF OF THE PENINSULA OVERNIGHT.
THEREFORE NOT EXPECTING ANY OVERNIGHT SHRAS ACROSS THE REGION ONCE
THE CURRENT SHRA ACROSS POLK FINALLY DISSIPATES. HAVE MADE
APPROPRIATE CHANGES TO LOWER POPS FOR REMAINDER OF THE NIGHT.
OTHERWISE...SOME PATCHY OVERNIGHT FOG IS THE ONLY WEATHER CONCERN
FOR TONIGHT.

&&

.AVIATION...PATCHY FOG DEVELOPING LATE TONIGHT INTO EARLY
WEDNESDAY MORNING MAY BRING TEMPO MVFR VISIBILITIES TO THE
TERMINAL SITES BETWEEN 08-12Z...OTHERWISE VFR IS EXPECTED.
SCATTERED SHOWERS AND STORMS WILL AGAIN DEVELOP ALONG THE SEA
BREEZE ON WEDNESDAY WITH TEMPO MVFR/IFR CIGS AND VSBYS POSSIBLE AT
KLAL AFTER 18Z WITH VCTS AT ALL OTHER TERMINALS...OTHERWISE VFR
WILL CONTINUE. VARIABLE WINDS 5 KNOTS OR LESS THE REST OF TONIGHT
WILL BECOME SOUTHWEST TO WEST AT 7 TO 10 KNOTS AFTER 18Z AS THE
SEA BREEZE DEVELOPS...WITH GUSTS UP TO 30 KNOTS IN THE VICINITY OF
THUNDERSTORMS.


&&

.PREV DISCUSSION... /ISSUED 311 PM EDT TUE MAY 21 2013/

SHORT TERM (TONIGHT - THURSDAY)...WEAK MID-LEVEL LOW OVER NORTH
FLORIDA IS FORECAST TO REMAIN NEARLY STATIONARY THROUGH TONIGHT THEN
MOVE SLOWLY NORTHEAST ON WEDNESDAY. DRIER AIR HAS MOVED IN BEHIND
THE LOW TO THE SOUTH OF TAMPA...BUT THE AIRMASS IS NOT DRY ENOUGH TO
INHIBIT THUNDERSTORM DEVELOPMENT THIS AFTERNOON. COUNTER-CLOCKWISE
FLOW AROUND THE LOW WILL LIKELY ALLOW STORMS NORTH OF TAMPA TO MOVE
BACK TOWARD THE COAST WHILE STORMS TO THE SOUTH PUSH FARTHER INLAND.
WEAK STEERING FLOW IN THE MIDDLE MEANS STORM MOTION WILL BE DICTATED
BY OUTFLOW BOUNDARIES AND THEREFORE QUITE UNPREDICTABLE.

SHOWERS AND STORMS WIND DOWN TONIGHT WITH SOME PATCHY FOG
DEVELOPING...ESPECIALLY WHERE THE GROUND REMAINS WET FROM PREVIOUS
SHOWERS.

ON WEDNESDAY...A WEAK AREA OF HIGH PRESSURE AT THE SURFACE WILL BE
IN PLACE OVER FLORIDA AND THE EASTERN GULF. THIS SHOULD ALLOW
AFTERNOON SEA BREEZES TO PENETRATE WELL INLAND AND FOCUS THE STORMS
ALONG THE SPINE OF THE PENINSULA. STEERING LEVEL FLOW WILL BE NEXT
TO NOTHING...SO ONCE AGAIN OUTFLOW BOUNDARIES WILL DICTATE WHERE
STORMS MOVE/DEVELOP DURING THE LATE AFTERNOON AND EVENING HOURS.

THURSDAY WILL BE SIMILAR...BUT THE ATMOSPHERE BETWEEN 700 AND 850
MBS DRIES CONSIDERABLY. THIS WILL DELAY DEVELOPMENT AS WELL AS LIMIT
THE OVERALL EXTENT OF STORMS. AFTER A COUPLE OF DAYS OF SCATTERED TO
NUMEROUS SHOWERS AND STORMS...IT LOOKS LIKE THURSDAY WILL JUST HAVE
ISOLATED STORMS...AND THEN MAINLY INLAND.

LONG TERM (THURSDAY NIGHT-MONDAY)...
HIGH AMPLITUDE PATTERN WILL PERSIST WITH A L/W TROUGH OVER THE
EASTERN U.S. WITH A STRONG CUT-OFF LOW DEVELOPING FRIDAY OVER THE
MID ATLANTIC. AS THE TROUGH AXIS PUSHES EAST OF FLORIDA ON
FRIDAY...A COLD FRONT WILL MOVE ACROSS REGION WITH A SLIGHT CHANCE
OF THUNDERSTORMS. SURFACE HIGH PRESSURE WILL BUILD OVER THE
FORECAST AREA FRIDAY NIGHT AND SATURDAY WITH SLIGHTLY DRIER AIR
ADVECTING ACROSS THE REGION. HIGH PRESSURE WILL MOVE TO THE MID
ATLANTIC COAST SUNDAY AND OVER THE WESTERN ATLANTIC MONDAY...WHILE
U/L RIDGING OVER THE CENTRAL U.S. WILL BEGIN TO GRADUALLY EDGE
EAST. THIS WILL KEEP BROAD EASTERLY BOUNDARY LAYER FLOW ACROSS THE
FORECAST AREA WITH SUBSIDENCE ALOFT AND A LOW CHANCE OF RAIN EACH
DAY.

AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE
THROUGH ABOUT 22/02Z. MAJORITY OF THIS CONVECTION WILL BE OVER
INLAND AREAS AND SHOULD STAY EAST OF TPA...PIE AND SRQ...BUT COULD
IMPACT LAL...PGD...FMY AND RSW CAUSING SOME MVFR/LOCAL IFR
CONDITIONS. OTHERWISE...VFR CONDITIONS ARE EXPECTED.

MARINE...NO ISSUES THROUGH FRIDAY AS A WEAK AREA OF HIGH PRESSURE
KEEPS WINDS LIGHT WITH SOME ENHANCEMENT TO ONSHORE WINDS NEAR THE
COAST DURING THE AFTERNOON SEA BREEZES EACH DAY. A STRONG AREA OF
HIGH PRESSURE WILL BUILD NORTH OF THE WATERS BY SATURDAY MORNING
WHICH WILL PUSH A SHEAR LINE THROUGH THE REGION. THE PRESSURE
GRADIENT WILL TIGHTEN SIGNIFICANTLY RESULTING IN ROBUST EAST TO
NORTHEAST FLOW OVER THE WEEKEND...POSSIBLY REQUIRING SMALL CRAFT
ADVISORIES AT TIMES.

FIRE WEATHER...NO HUMIDITY PROBLEMS EXPECTED. LIGHT TRANSPORT WINDS
ON WEDNESDAY WILL LEAD TO RATHER POOR DISPERSIONS.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  71  87  72  88 /  10  20  20  10
FMY  71  90  71  91 /  10  30  20  10
GIF  69  89  70  91 /  20  60  20  20
SRQ  69  87  70  87 /  10  20  20  10
BKV  64  88  66  89 /  10  30  20  10
SPG  73  87  73  88 /  10  20  20  10

&&

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

$$

SHORT TERM/MARINE/FIRE WEATHER...88/GITTINGER
LONG TERM/AVIATION...57/MCMICHAEL