Severe Thunderstorm Warning 68, NWS Miami, FL

SOUTH FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
253 PM EDT WED JUL 21 2004

.UPDATED...QUICK UPDATE TO LOWER POPS TO ISOLATED FOR NORTHEAST AND
INTERIOR REGIONS...AND TO SCATTERED FOR SOUTHEAST AREAS OF SOUTH
FLORIDA...AS MOST OF THE ACTIVITY AS MOVED INTO THE ATLANTIC WATERS.
PLAN TO INCREASE POPS A LITTLE THIS EVENING TO SCATTERED FOR THE
WEST COAST...AS SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOP
ALONG THE WEST COAST. MAIN UPDATE WILL BE AROUND 9 PM TONIGHT.

BAXTER

.PREVIOUS DISCUSSION...MESOSCALE ANALYSES TOOLS AND OBS SUGGEST THAT
WEAK SURFACE TROUGH IS JUST NORTH OF LAKE OKEECHOBEE THIS AFTERNOON.
SCATTERED THUNDERSTORMS ARE DEVELOPING AS EXPECTED OVER THE
NORTHWESTERN SOUTH FLORIDA ZONES AHEAD OF A H5 SHORTWAVE MOVING IN
FROM THE GULF OF MEXICO. AIRCRAFT SOUNDING DATA FROM RSW/MIA
INDICATE 500 MB TEMPS HAVE COOLED A COUPLE DEGREES FROM MORNING
SOUNDING...SO THE ATMOSPHERE IS INDEED BECOMING INCREASINGLY
UNSTABLE. SEABREEZE BEGINNING TO MOVE INLAND AS INTERIOR TEMPS HAVE
REACHED THE LOWER 90S. THUS...EXPECT STORMS TO CONTINUE DEEPENING
WHILE THEY SPREAD EAST AND SOUTH ACROSS OUR PORTION OF THE
PENINSULA. THUNDERSTORMS SHOULD RAPIDLY DIMINISH AFTER
SUNSET...THOUGH SOME ACTIVITY IS POSSIBLE UNTIL SURFACE TROUGH
SHIFTS SOUTH OF THE AREA EARLY THURSDAY MORNING.

PRECIP CHANCES LOWER THURSDAY AND FRIDAY AS SUBSIDENCE INCREASES
WITH 850-500MB LAPSE RATES ARE ONLY NEAR 4 DEG C/KM. HIGH DEWPOINTS
NEAR THE SURFACE THOUGH WILL PROVIDE FOR AT LEAST A FEW AFTERNOON
SEABREEZE STORMS HOWEVER.

MOISTURE BEGINS TO INCREASE SLIGHTLY BY SATURDAY AS WINDS TURN BACK
OUT OF THE EAST AT ALL LEVELS...HOWEVER LIGHT. THUS NEAR CLIMO POPS
FROM SATURDAY ON...WITH ONE CAVEAT.

THE TROPICAL WAVE SOUTH OF HISPANIOLA SEEMS TO BE GETTING BETTER
ORGANIZED AND IS RAPIDLY TRACKING WESTWARD. ALL MODELS IN RATHER
GOOD AGREEMENT IN NOT SUGGESTING MUCH DEVELOPMENT...BUT INSTEAD
STRETCHING/ELONGATING IT NORTHWARD TO BRING INCREASED MOISTURE
ASSOCIATED WITH THE WAVE EXTENDING FROM SOUTH FLORIDA TO THE
CARIBBEAN BY THE WEEKEND. DECIDED TO NUDGE POPS UP SLIGHTLY ABOVE
GFS MOS TO HIGHER SCATTERED (40-50%) FOR SUNDAY AS THIS WOULD BE THE
TIME FRAME OF BEST SHOWER ACTIVITY FOR SOUTH FLORIDA.

THE ATLANTIC RIDGE MAY AGAIN STRENGTHEN ACROSS THE ATLANTIC AND
FLORIDA TOWARD THE END OF THE FORECAST PERIOD...WHICH COULD REDUCE
EAST COAST POPS A TAD BELOW 40...AND WEST COAST SLIGHTLY
HIGHER...BUT WILL MAINTAIN NEAR CLIMATOLOGY AND GUIDANCE FOR NOW.
&&

.MARINE...LIGHT WINDS AND LOWER SEAS THROUGH THE PERIOD.
&&

.FIRE WEATHER...NO CONCERNS.
&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.

&&

HANDEL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MIAMI FL
424 AM EDT WED JUL 21 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA

FLZ063-066>075-212200-
BROWARD METROPOLITAN-DADE METROPOLITAN-EASTERN COLLIER-GLADES-HENDRY-
MAINLAND MONROE-PALM BEACH EASTERN-PALM BEACH WESTERN-
WESTERN BROWARD-WESTERN COLLIER-WESTERN DADE-
424 AM EDT WED JUL 21 2004

.DAY ONE...TODAY

...MODERATE RISK OF LIGHTNING TODAY...
...A FEW STRONG STORMS POSSIBLE THIS AFTERNOON...
...LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE...

MOISTURE AND INSTABILITY WILL CONTINUE HIGH ACROSS THE AREA
TODAY...AHEAD OF A WEAK TROUGH ACROSS CENTRAL FLORIDA. THIS WILL
CREATE AN ENVIRONMENT FAVORABLE FOR SCATTERED THUNDERSTORMS...A FEW
STRONG WITH GUSTY WINDS. LOCALLY HEAVY RAINFALL IS POSSIBLE AS
WELL...POTENTIALLY LEADING TO LOCALIZED STREET FLOODING.

ADDITIONAL INFORMATION AND DETAILED GRAPHICS CAN BE FOUND ON THE
NATIONAL WEATHER SERVICE WEB SITE AT MIAMIWEATHER.INFO. FOR
INFORMATION IN SPANISH, VISIT OUR WEB SITE AT ELTIEMPOENMIAMI.INFO.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.