Hail in Florida, March 13, 2003

EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
300 PM EST THU MAR 13 2003

...ENHANCED RAIN CHANCES INTO THE WEEKEND WITH POTENTIAL FOR STRONG
STORMS...

16Z CAPE SOUNDING SHOWS OFFSHORE FLOW STRONGER THAN MODELS FORECAST.
AS EXPECTED SEA BREEZE HAS DEVELOPED IN MARTIN COUNTY FIRST BUT THE
ONSET MAY BE LATER THAN EXPECTED ELSEWHERE. CU REMAINS QUITE
SUPPRESSED WITH WEST COAST SEA BREEZE NOT PRODUCING ANY CONVECTION.
SEE PREVIOUS AFD ISSUED AT 1 PM REGARDING CONVECTIVE THREAT THIS
AFTN/EVE FOR EC FL.

MODELS AGREE IN DEVELOPING A CUT-OFF LOW OVER THE LOWER MS VALLEY
EARLY FRI AND CONTINUING THROUGH SAT. THIS WILL ADD DIFFLUENCE ALOFT
TO THE ALREADY LOADED ATM. STEEP LAPSE RATES AND COLD AIR ALOFT WILL
COMBINE WITH SUFFICIENT MOISTURE...AND SOON UPPER LEVEL DYNAMICS...
TO PRODUCE HIGHER COVERAGE OF STORMS FRI AND SAT WITH POTENTIAL OF
SEVERE STORMS. AS A RESULT...ONCE CONVECTION GETS GOING FRI AFTN IT
WILL NOT STOP...CONTINUING OVERNIGHT FRI. WE WILL NOT BE AS
SUPPRESSED FRI...SO EXPECT EARLIER CONVECTIVE INITIATION THAN TODAY.
PLUS...WITH FRONTAL ZONE ACROSS THE AREA GRADIENT WILL BE WEAKER SO
SEA BREEZE WILL DEVELOP EARLIER AND MAKE IT FARTHER INLAND. THIS
WILL KEEP MLB/VRB/FPR TEMPS COOLER THAN TODAY.

NOT SURE WHY AVN POPS ARE LOWER SOUTH THAN NORTH FRI...AND THINK
OVERALL POPS ARE A LITTLE LOW. SO WILL RAISE EVERYONE TO 40%. WILL
FOLLOW HIGH AVN MOS POPS FRI NIGHT AND SAT.

UPPER LOW WEAKENS BY SUN AND LIFTS NE. SHOULD SEE A RESPITE FROM THE
HIGH POPS BUT SCATTERED CONVECTION STILL EXPECTED SUN. PASSAGE OF
UPPER TROUGH SHOULD BRING IN SOME DRIER AIR MON SO WILL LEAVE RAIN
CHANCES OUT. EXTENDED AVN BRINGS THE NEXT FRONT THROUGH WED NIGHT
WITH A BAND OF CONVECTION. BUT SFC HIGH BEHIND IT IS VERY WEAK (1019
MB). STRONGLY SUSPECT TIMING OF THIS IS TOO FAST. WILL HOLD OFF ON
RAIN CHANCES WITH THIS NEXT FRONT AND KEEP WED/THU DRY FOR NOW.

PRELIM CCF NUMBERS...
DAB BT 063/080 065/078 063 3477
MCO BT 064/085 065/083 064 1477
MLB BT 065/081 067/082 063 3477

.MLB...NONE.

PUBLIC/MARINE...KELLY
AVIATION/FIRE WX...GITTINGER

AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-141-144-147-
132200-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MELBOURNE FL
1115 AM EST THU MAR 13 2003

.DAY ONE...THIS AFTERNOON:

...SCATTERED STRONG TO SEVERE THUNDERSTORMS POSSIBLE TODAY...

SLOWLY INCREASING MOISTURE AND UPPER LEVEL IMPULSES MOVING OVERHEAD
WILL PRODUCE A VERY UNSTABLE ATMOSPHERE ACROSS CENTRAL FLORIDA THIS
AFTERNOON. DAYTIME HEATING WILL INCREASE THE INSTABILITY AND ALLOW
LAKE AND SEA BREEZE DEVELOPMENT AS WELL. THESE LAKE AND SEE BREEZE
BOUNDARIES...AS WELL AS THUNDERSTORM OUTFLOW BOUNDARIES APPROACHING
FROM THE NORTH WILL PROVIDE A FOCUS FOR SCATTERED THUNDERSTORM
DEVELOPMENT THIS AFTERNOON AND EVENING.

WITH ATMOSPHERIC MOISTURE REMAINING SLIGHTLY LIMITED...THUNDERSTORM
COVERAGE IS EXPECTED TO REMAIN SCATTERED. HOWEVER...SMALL UPPER LEVEL
DISTURBANCES AND COLDER THAN NORMAL AIR IN THE UPPER LEVELS OF THE
ATMOSPHERE WILL PROVIDE AN ENVIRONMENT THAT IS FAVORABLE FOR STRONG
TO SEVERE THUNDERSTORM DEVELOPMENT. THEREFORE...ANY THUNDERSTORMS
THAT DO FORM TODAY WILL HAVE THE POTENTIAL TO PRODUCE EXCESSIVE
LIGHTNING STRIKES...DAMAGING WIND GUSTS IN EXCESS OF 60 MPH AND COIN
SIZE HAIL. THUNDERSTORMS WILL GENERALLY MOVE EAST TO NORTHEAST AT 20
TO 30 MPH...WITH THE STORMS EVENTUALLY PUSHING ACROSS THE
INTRACOASTAL WATERWAYS AND OFFSHORE INTO THE ATLANTIC OCEAN.

PERSONS IN EAST CENTRAL FLORIDA...INCLUDING MARINE INTERESTS...
SHOULD KEEP ALERT FOR APPROACHING STORMS. OPEN PLACES SUCH AS BEACHES
AND GOLF COURSES ARE NOT SAFE FROM THE LIGHTNING DANGER DURING
STORMS...NOR ARE THE OPEN AIR SHELTERS AT MANY OUTDOOR RECREATION
AREAS. CONTINUE TO MONITOR NOAA WEATHER RADIO OR LOCAL MEDIA
OUTLETS FOR STATEMENTS OR WARNINGS REGARDING THIS WEATHER SITUATION
AND BE PREPARED TO TAKE SHELTER IN A STURDY BUILDING BEFORE STORMS
ARE OVERHEAD.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY:

A PERSISTENT MOIST AND UNSTABLE AIR MASS ALONG WITH AN UPPER LEVEL
LOW PRESSURE AREA MOVING ACROSS THE GULF COAST STATES WILL CONTINUE
STORM CHANCES FRIDAY AND INTO THE WEEKEND.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTERS SHOULD SELF ACTIVATE IF A WARNING IS ISSUED FOR THEIR
COUNTY TODAY.

MJG