Hail in Florida, April 10, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
1020 AM EDT MON APR 10 2006

.UPDATE...THE MORNING MIAMI SOUNDING IS STILL UNSTABLE...BUT NOT
AS UNSTABLE AS YESTERDAY. ALTHOUGH THE H5 TEMP IS COLDER THAN
24 HRS AGO...AT -13.1C...THE ATMOSPHERE HAS COOLED AT THE SURFACE AND
LOWER LEVELS...COMPENSATING FOR THE COLDER MID LEVEL AIR.
STILL...IT IS UNSTABLE...AS THE MODIFIED MIA SOUNDING FOR EXPECTED
AFTERNOON MAXES YIELDS A CAPE OF 2500 J/KG...LI OF -7C...AND A
K-INDEX OF 30. ALTHOUGH BEST CONVERGENCE IS SOUTHEAST OF THE AREA
ALONG THE SURFACE FRONT...EXPECT THIS UNSTABLE AIRMASS TO ALLOW
FOR SCT-NUM SHOWERS AND ISOLATED THUNDERSTORMS TO AFFECT THE
ATLANTIC COAST...DUE TO COASTAL CONVERGENCE IN THE STRENGTHENING
NE FLOW. SOME OF THIS ACTIVITY...AS SHOWN BY THE WRF...MAY MOVE
ACROSS THE PENINSULA AND/OR DEVELOP ESPECIALLY LATE THIS AFTERNOON
AS THE NE FLOW STRENGTHENS. UPDATED THE FORECAST ONLY TO INCREASE
POPS INTO THE LIKELY CATEGORY EAST COAST ZONES. WET BULB ZERO
HEIGHT IS BELOW 10K FT...SO ANY OF THE STORMS THAT DEVELOP THIS
AFTERNOON COULD CONTAIN SMALL HAIL...SO WE WILL UPDATE THE HWO TO
REFLECT THIS POSSIBILITY. /DG

&&

.PREV DISCUSSION...
DISCUSSION...FRONTAL BOUNDARY DRIFTING SOUTHEAST ACROSS SOUTHEAST
FLORIDA WHERE CONVECTION HAS BEEN FIRING UP MOST OF THE LATE NIGHT
AND EARLY MORNING HOURS. SOME OF THE INTENSE STORMS OVER WATER
PROMPTED SEVERAL SPECIAL MARINE WARNINGS. MODELS WANT TO STALL
THIS BOUNDARY ACROSS OUR AREA TODAY AND TONIGHT WHILE AT THE SAME
TIME THE UPPER TROUGH MOVES EAST ACROSS THE PENINSULA THIS
AFTERNOON AND EVENING BRINGING COOLER AIR ALOFT AND FURTHER
DESTABILIZING THE LOCAL ATMOSPHERE. AN INCREASING NORTHEAST LOW
LEVEL FLOW NORTH OF THE BOUNDARY WILL ALSO ENHANCE LOW LEVEL
CONVERGENCE ACROSS THE AREA. DECIDED TO INCREASE POPS FOR
TODAY...ESPECIALLY ACROSS MIAMI-DADE/BROWARD COUNTIES TO ACCOUNT
MORE THIS.

A SURFACE HIGH PRESSURE RIDGE OVER EASTERN U.S. WILL MOVE EAST
OVER THE WESTERN ATLANTIC TONIGHT AND AS IT DOES SO THE PRESSURE
GRADIENT WILL TIGHTEN WHICH IN TURN WILL RESULT IN INCREASING NE
WINDS (AS MENTIONED ABOVE). THIS WILL NOT ONLY ENHANCE LOW LEVEL
CONVERGENCE BUT WILL ALSO HELP TO ADVECT LOW LEVEL MOISTURE/LEFT
OVER CONVECTION BACK WEST TO SOUTH FLORIDA. SO, EVEN THOUGH, WILL
GRADUALLY DECREASE POPS, WILL KEEP AT LEAST A SLIGHT CHANCE AT
LEAST THROUGH WEDNESDAY.

MARINE...AS MENTION BEFORE...PRESSURE GRADIENT WILL TIGHTEN
ACROSS SOUTH FLORIDAS WATERS AND SO SFC WINDS WILL INCREASE TO 20
TO 25 KTS WITH HIGHER GUSTS AS EARLY AS THIS AFTERNOON OVER THE
NORTHERN ATLANTIC WATERS...LAKE OKEECHOBEE AND PORTIONS OF THE
GULF WATERS. A SMALL CRAFT ADVISORY IS NOW IN EFFECT FOR THOSE
WATERS. THESE STRONG NORTHEAST WINDS ALONG WITH VERY ROUGH SEAS
SHOULD CONTINUE TO AFFECT THE ATLANTIC WATERS AT LEAST THROUGH
TUESDAY NIGHT WITH A SLIGHT IMPROVEMENT ON WEDNESDAY.

FIRE WEATHER...NO CONCERNS AT THIS TIME.

EXTENDED FORECAST...ATLANTIC RIDGE WILL CONTINUE TO ADVECT LOW
LEVEL MOISTURE WEST THROUGH THE ENTIRE EXTENDED PERIOD...SO WILL KEEP
SLIGHT CHANCE OF SHOWERS IN THE FORECAST THROUGH DAY SEVEN.

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR COASTAL
     WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
     COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
     OUT 20 NM-LAKE OKEECHOBEE-WATERS FROM DEERFIELD BEACH TO
     OCEAN REEF, FL EXTENDING FROM 20 NMTO THE TERRITORIAL
     WATERS OF THE BAHAMAS-WATERS FROM JUPITER INLET TO
     DEERFIELD BEACH, FL EXTENDING FROM 20 NM TO 60 NM.

GM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR COASTAL
     WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-GULF
     WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM
     20 TO 60 NM.

&&

57

HAZARDOUS WEATHER OUTLOOK FOR SOUTH FLORIDA...UPDATED
NATIONAL WEATHER SERVICE MIAMI FL
1058 AM EDT MON APR 10 2006

FLZ063-066>075-111500-
GLADES-HENDRY-PALM BEACH WESTERN-PALM BEACH EASTERN-
WESTERN COLLIER-EASTERN COLLIER-WESTERN BROWARD-
BROWARD METROPOLITAN-WESTERN DADE-DADE METROPOLITAN-
MAINLAND MONROE-
1058 AM EDT MON APR 10 2006

...HIGH RISK OF RIP CURRENTS ALL ATLANTIC BEACHES...
...ISOLATED STORMS CONTAINING SMALL HAIL POSSIBLE THIS AFTERNOON...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...TODAY AND TONIGHT

RIP CURRENTS: NORTHEAST WINDS OF NEAR 20 MPH, ALONG WITH AN
AFTERNOON LOW TIDE, WILL RESULT IN A HIGH RISK OF RIP CURRENTS AT
THE ATLANTIC BEACHES OF PALM BEACH, BROWARD, AND MIAMI-DADE
COUNTIES THIS AFTERNOON AND EVENING.

THUNDERSTORMS: ISOLATED THUNDERSTORMS WILL OCCUR ACROSS THE AREA
THIS AFTERNOON. FREQUENT LIGHTNING WILL OCCUR WITH SOME OF THE STORMS
THAT DEVELOP.

HAIL: COLD AIR ALOFT WILL RESULT IN THE POSSIBILITY OF SMALL HAIL
WITH THE STRONGEST THUNDERSTORMS THIS AFTERNOON.

WAVES: SEAS IN THE GULF STREAM WILL BUILD TO 11 FEET BY TONIGHT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

STRONG NORTHEAST WINDS WILL PRODUCE HIGH SEAS ABOVE 8 FEET IN THE
GULF STREAM THROUGH THURSDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

FOR MORE INFORMATION...VISIT THE NATIONAL WEATHER SERVICE IN
MIAMI WEBSITE AT WWW.MIAMIWEATHER.INFO.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MIAMI FL
101 PM EDT MON APR 10 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1249 PM     HAIL             SWEETWATER              25.76N 80.37W
04/10/2006  E0.88 INCH       MIAMI-DADE         FL   NWS EMPLOYEE

1250 PM     HAIL             SWEETWATER              25.76N 80.37W
04/10/2006  E0.25 INCH       MIAMI-DADE         FL   NWS EMPLOYEE

            PEA SIZE HAIL FELL AT WFO MIAMI.

&&

DG