Severe Thunderstorm Warning 27, NWS Miami, FL

SOUTH FLORIDA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI
115 PM EDT SUN MAY 18 2003

.TONIGHT THROUGH TUESDAY NIGHT...
12Z MFL SOUNDING SHOWED A LOWERING OF PWS COMPARED TO THE PAST FEW
DAYS. EASTERLY FLOW IS STILL FAIRLY DEEP UP TO 600 MB AND THEN BACKS
TO THE WEST ABOVE THAT LEVEL. MODEL GUIDANCE SHOWS A BACK-DOOR COLD
FRONT CONTINING TO MOVE SOUTHWARD IN THE ATLANTIC, AND THE HIGH
BEHIND IT ALONG THE EAST COAST OF THE U.S. WILL LIKELY BRIDGE ACROSS
IT BY MONDAY. THIS SHOULD BEGIN TO SLIGHTLY STRENGTHEN OUR EASTERLY
FLOW PATTERN. AT THE SAME TIME, THE UPPER LOW OVER THE CENTRAL GULF
COAST AREA WILL GRADUALLY WEAKEN AND DRIFT SOUTHWARD INTO THE GULF,
AND THE TROUGH OVER THE WESTERN ATLANTIC (WHICH HAS BEEN SHOVING THE
BACK-DOOR FRONT SOUTHWARD) IS FORECAST TO DEEPEN AND DIG SOUTHWARD
(AND ACTUALLY RETROGRADE A BIT WESTWARD) THROUGH TUESDAY. AS A
RESULT OF THIS, OUR UPPER WIND FLOW WHICH IS NOW SOUTHWEST TO WEST
WILL BECOME MORE NORTH TO NORTHEAST. WITH THE DEEPENING AND
RETROGRADING TROUGH NEAR US, AND THE UPPER STEERING FLOW BECOMING
MORE FROM THE NORTH-NORTHEAST WITH TIME. THE OVERALL RESULT SHOULD
BE SLIGHTLY HIGHER POPS THAN PREVIOUSLY FORECAST FOR MONDAY THROUGH
TUESDAY. FORECASTED SOUNDINGS SHOW THE H5 TEMP DROPING FROM -8 TODAY
TO -10 FOR MONDAY AND TUESDAY. THE OVERALL RESULT SHOULD BE SLIGHTLY
HIGHER POPS FOR MONDAY THROUGH TUESDAY EVERYWHERE AND THERE IS A
POSSIBILITY OF A FEW STRONG STORMS. MOS GUIDANCE (AT LEAST THE FWC
AND MET MOS) SEEMS TO CONFIRM THIS TREND. MAV NUMBERS ARE NOW
FOLLOWING THIS TREND ALSO BUT POPS ARE A LITTLE LOWER.

.EXTENDED WEDNESDAY THROUGH SUNDAY...
LITTLE CHANGE FROM THE EARLIER FORECASTS WEDNESDAY THROUGH THURSDAY,
WITH CHANCE CATEGORY MAINLY DAYTIME AND EVENING POPS. POPS WILL BE
SLIGHTLY LOWER AND COULD BE ANYTIME ALONG THE EAST COAST WITH THE
MODERATELY DEEP EASTERLY FLOW. FOR FRIDAY AND SATURDAY...MORE CLOUDS
AND AGAIN SLIGHTLY HIGHER POPS WILL BE FORECASTED, AS A WEAKENING
COLD FRONT WILL APPROACH SOUTH FLORIDA WITH INCREASING MOISTURE AND
LIFT. MRF SHOWS THE FRONT REACHING EXTREME SOUTH FLORIDA SATURDAY
NIGHT. DRYER AIR EXPECTED SUNDAY.

.MARINE...
MOSTLY LIGHT EASTERLY FLOW IS EXPECTED THROUGH MONDAY NIGHT, WITH
THE GRADIENT FLOW WEAK ENOUGH TO ALLOW FOR A WEST COAST SEA BREEZE
EACH AFTERNOON. BY TUESDAY AND WEDNESDAY, SLIGHTLY STRONGER
EASTERLIES MAY BE ENOUGH TO INHIBIT THE WEST COAST SEA BREEZE.
WINDS WILL BEGIN TO SHIFT BACK TO THE SOUTHEAST OR SOUTH AND LIGHT
AGAIN FOR THURSDAY AND FRIDAY AHEAD OF THE FRONTAL SYSTEM MENTIONED
ABOVE.

.FIRE WEATHER...
NO PROBLEMS ARE ANTICIPATED.

PBI EE 077/089 076/087 075 182434
FLL EE 078/087 077/087 076 182434
MIA EE 077/088 076/087 075 182434
APF EE 072/088 072/088 071 182434

.MIA...NONE.

FLZ063-066>075-182000-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MIAMI FL
910 AM EDT SUN MAY 18 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...TODAY

...SCATTERED AFTERNOON THUNDERSTORMS WILL FAVOR INLAND AND WESTERN
SOUTH FLORIDA THIS AFTERNOON...

SCATTERED THUNDERSTORMS WILL DEVELOP IN THE MOIST UNSTABLE
ATMOSPHERE OVER SOUTH FLORIDA THIS AFTERNOON. MOST OF THE
THUNDERSTORMS WILL OCCUR OVER INLAND AREAS AWAY FROM THE BEACHES...
INCLUDING THE WESTERN METRO AREAS OF PALM BEACH...BROWARD AND
MIAMI-DADE COUNTIES. THE GREATEST THREAT FROM STORMS TODAY WILL BE
CLOUD TO GROUND LIGHTNING STRIKES. SLOW MOVEMENT OF SOME STORMS MAY
LEAD TO RAIN ACCUMULATIONS OF 2 TO 4 INCHES IN ISOLATED SITUATIONS.
THIS AMOUNT OF RAINFALL COULD PRODUCE MINOR FLOODING IN STREETS AND
OTHER LOW-LYING AREAS. IN ADDITION...WIND GUSTS OF 40 TO 50 MPH ARE
POSSIBLE WITH THE STRONGER THUNDERSTORMS AROUND LAKE OKEECHOBEE.

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...MONDAY THROUGH SATURDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.