Wildfire in Florida, April 26 to 30, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
128 PM EDT TUE APR 26 2011

.AVIATION...VFR CONDITIONS EXPECTED THROUGH THE PERIOD. SHOWER
ACTIVITY EXPECTED TO DEVELOP AT AROUND 20Z...THEREFORE ADDED VCSH
FOR THE EAST COAST TERMINALS. ACTIVITY COULD GET STRONGER NEAR
KPBI...FOR THIS REASON KEPT VCTS FOR THIS ONE. SE FLOW WILL
CONTINUE THROUGH THE PERIOD...GUSTING TO 20 KTS FOR THE EASTERN
TERMINALS. SHRA/TS DISSIPATING BY 27/01Z...WITH WINDS SLOWING DOWN
TO AROUND 8 KTS. FOR KAPF...EASTERLY FLOW PREVAILING THROUGH THE
DAY GUSTING TO AROUND 15 KTS...SLOWING DOWN TO LIGHT AND VRB BY
27/01Z.

&&

.PREV DISCUSSION... /ISSUED 1025 AM EDT TUE APR 26 2011/

..A FEW STRONG STORMS POSSIBLE LAKE OKEECHOBEE AND NORTHEAST
AREAS OF THE CWA THIS AFTERNOON...

UPDATE...
THE SURFACE RIDGE OF HIGH PRESSURE HAS SHIFTED SOUTH FROM WESTERN
ATLANTIC WATERS TO EAST OF THE BAHAMA ISLANDS THIS MORNING. THIS
WILL ALLOW FOR THE STEERING FLOW TO BE FROM THE SOUTH TO
SOUTHWEST OVER THE CWA...AND KEEP THE EAST COAST SEA BREEZE NEAR
THE EAST COAST METRO AREAS THIS AFTERNOON. THE WEST COAST SEA
BREEZE WILL ALSO PUSH ACROSS THE CWA TODAY AND MEET UP WITH THE
EAST COAST SEA BREEZE LATE THIS AFTERNOON INTO EARLY THIS EVENING.

AT THE SAME TIME...THE 12Z MIA SOUNDING THIS MORNING SHOWS THAT
THE ATMOSPHERE HAS BECOME MORE UNSTABLE ACROSS THE CWA WITH 500 MB
TEMPS AROUND -10C WITH THE 850 MB TEMP AROUND 18C. SO HAVE RAISED
THE POPS TO 50 PERCENT OVER THE LAKE OKEECHOBEE AND NORTHEAST
AREAS OF THE CWA THIS AFTERNOON WITH 30 TO 40 PERCENT POPS FOR
REST OF THE EAST COAST METRO AREAS. THE POPS FOR THE WEST COAST
METRO AREA HAS BEEN DECREASED TO AROUND 10 PERCENT FOR THIS
AFTERNOON DUE TO THE SOUTHWEST STEERING FLOW.

THERE COULD BE SOME STRONG STORMS OVER THE NORTHERN INTERIOR AND
NORTHEAST AREAS OF THE CWA THIS AFTERNOON INTO EARLY THIS
EVENING...DUE TO THE COLD AIR ALOFT AND A MID TO UPPER LEVEL JET
OF 50 TO 70 KNOTS MOVING THROUGH THE AREA FROM THE SOUTHERN GULF
OF MEXICO. SO WILL UPDATED THE HWO TO SHOW THE STRONG STORMS
POSSIBLE. THE PRIMARY IMPACTS AT THIS TIME WILL BE GUSTY WINDS AND
HAIL.

REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES
ARE PLAN.

UPDATED...54/BNB

PREV DISCUSSION... /ISSUED 356 AM EDT TUE APR 26 2011/

DISCUSSION...EARLY MORNING SATELLITE AND RADAR DATA SHOWS CONVECTION
CONTINUING TO DEVELOP OVER THE WESTERN ATLANTIC AND NEAR THE
BAHAMAS AS THE MEAN LOW LEVEL FLOW BECOMES MORE SOUTHEASTERLY.
MEANWHILE, A MID LEVEL LOW IS SLOWLY PASSING OVERHEAD...AND WILL
SHIFT JUST EAST OF THE LOCAL AREA BY DAYBREAK. MORE NOTABLY, A
LOW LEVEL VORT MAX WILL CONTINUE TO APPROACH THE EAST COAST OF
FLORIDA AND ULTIMATELY DRIFT TO THE NORTH-NORTHEAST AS AN
INVERTED TROUGH REMAINS NEARLY STATIONARY ALONG THE WESTERN
FRINGE OF AN ATLANTIC RIDGE. OVERALL, THIS SYNOPTIC PATTERN WILL
FAVOR THE TRANSPORT OF HIGHER PRECIPITABLE WATERS TO THE REGION,
ALTHOUGH THE BULK OF THE DEEPEST MOISTURE WILL LIKELY REMAIN JUST
TO OUR EAST. THAT SAID, IF DEEPER CONVECTION CAN REACH THE GULF
STREAM WATERS EARLY THIS MORNING, SHOWERS AND THUNDERSTORMS MAY
BECOME MORE NUMEROUS OVER EASTERN PORTIONS OF THE AREA LATER
TODAY. WE HAVE MAINTAINED 30-40 POPS OVER THE EASTERN HALF OF THE
AREA, WHICH IS ALSO IN GOOD AGREEMENT WITH THE LATEST HI-RES RUC,
WRF, AND NAM12. THUNDERSTORM ACTIVITY SHOULD PEAK THIS AFTERNOON
OVER THE LAKE REGION AND SOUTHEAST INTO PALM BEACH AND BROWARD
COUNTIES AS LOCAL SEA AND LAKE BREEZES COMBINE WITH DIURNAL
HEATING AND INCREASED MOISTURE. SHOWERS AND THUNDERSTORMS WILL
GRADUALLY DIMINISH THIS EVENING WITH THE SOUTHWEST STEERING FLOW
BRINGING ANY REMNANT CONVECTION BACK TOWARD THE EAST COAST BEFORE
DISSIPATING BY LATE EVENING. SOME PATCHY FOG IS AGAIN POSSIBLE
OVER PORTIONS OF THE INTERIOR LATE TONIGHT.

CONTINUED SOUTH SOUTHEAST LOW LEVEL FLOW AND SUFFICIENT MOISTURE
WILL RESULT IN MORE CONVECTION ON WEDNESDAY...ESPECIALLY AS UPPER
LEVEL DIVERGENCE INCREASES OVER THE REGION AS A STRONG
DISTURBANCE MOVES OVER THE MISSISSIPPI VALLEY. THE GREATEST
CHANCE FOR CONVECTION APPEARS TO BE OVER THE INTERIOR, DUE TO THE
COLLISION OF SEA/LAKE BREEZE BOUNDARIES. INCREASED STORM MOTION
AND A GRADUAL LESSENING OF DEEP MOISTURE SHOULD LIMIT RAINFALL
AMOUNTS.

A WEAKENING FRONTAL BOUNDARY WILL THEN APPROACH THE REGION
THURSDAY WITH INCREASING SOUTHWESTERLY FLOW AHEAD OF IT. FOR NOW,
WE WILL CONTINUE TO CARRY 20-30 POPS, ALTHOUGH THE MOIST
SOUTHWEST FLOW AND ENHANCED LOW LEVEL CONVERGENCE MAY ULTIMATELY
WARRANT HIGHER POPS.

RIDGING WILL RETURN BY FRIDAY AND INTO NEXT WEEKEND WITH MORE
STABLE CONDITIONS AND AT LEAST A SHORT PERIOD OF SLIGHTLY COOLER
TEMPERATURES. ONSHORE FLOW WILL RESUME SATURDAY INTO SUNDAY AS
SURFACE HIGH PRESSURE MOVES TO THE SOUTHEAST.

AVIATION...06Z ISSUANCE...VFR CONDITIONS WILL PREVAIL THROUGH
THE NEXT 24 HOURS. A FEW CU FROM THE ATLANTIC AND HIGH CIRRUS
WILL AFFECT THE E CST TERMINALS THROUGH 14Z. SOME CONVECTIVE
ACTIVITY IS EXPECTED TO DEVELOP OVER THE MAINLAND BUT THE
STEERING FLOW WILL GUIDE THE CELLS INLAND AWAY FROM MOST
TERMINALS ESPECIALLY KAPF AND THE MOST SOUTHERN E CST SITES. THE
MOST VULNERABLE WILL BE KPBI AND THEY COULD EXPERIENCE A BRIEF
MVFR CIG/VSBY LATE IN THE AFTERNOON. A SE WIND WILL PERSIST AT
ALL SITES INCREASING TO 10-12 KT ALONG THE E CST AFT 13-14Z AND A
WEST COAST SEA BREEZE WILL DEVELOP AT KAPF AT 17-18Z.

MARINE...SOUTH SOUTHEAST WINDS, AVERAGING 12-18 KNOTS, WILL
PERSIST THROUGH TONIGHT. A SMALL CRAFT EXERCISE CAUTION STATEMENT
WILL LIKELY BE WARRANTED FOR THE OFFSHORE ATLANTIC WATERS. WINDS
WILL INCREASE A BIT WEDNESDAY INTO THURSDAY AHEAD OF AN
APPROACHING COLD FRONT.

FIRE WEATHER...RELATIVE HUMIDITIES ARE EXPECTED TO REMAIN ABOVE
CRITICAL THRESHOLDS FOR AT LEAST THE NEXT FEW DAYS WITH NO
SIGNIFICANT FIRE WEATHER CONCERNS.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  75  87  76  88 / 30 10 20 20
FORT LAUDERDALE  77  87  78  88 / 20 10 20 20
MIAMI            77  88  77  90 / 20 10 20 20
NAPLES           72  90  74  90 / 10 10 10 10

&&

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

DISCUSSION/MARINE...54/BNB
AVIATION/RADAR/FIRE...17/ERA

HAZARDOUS WEATHER OUTLOOK FOR SOUTH FLORIDA
NATIONAL WEATHER SERVICE MIAMI FL
927 AM EDT TUE APR 26 2011

FLZ063-066>075-168-172>174-270430-
GLADES-HENDRY-INLAND PALM BEACH-METRO PALM BEACH-COASTAL COLLIER-
INLAND COLLIER-INLAND BROWARD-METRO BROWARD-INLAND MIAMI DADE-
METRO MIAMI DADE-MAINLAND MONROE-COASTAL PALM BEACH-
COASTAL BROWARD-COASTAL MIAMI DADE-FAR SOUTH MIAMI DADE-
927 AM EDT TUE APR 26 2011

...CHANCE OF THUNDERSTORMS THIS AFTERNOON...
...MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...TODAY AND TONIGHT

RIP CURRENTS: A SOUTHEAST WIND OF 10 TO 15 MPH WILL CONTRIBUTE IN A
MODERATE RISK OF RIP CURRENTS AT THE BEACHES OF PALM BEACH,
BROWARD AND MIAMI-DADE COUNTIES TODAY.

THUNDERSTORMS: SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON
ACROSS EASTERN PORTIONS OF SOUTH FLORIDA. THE PRIMARY THREAT FROM THE
STRONGER STORMS WILL BE OCCASIONAL LIGHTNING STRIKES, GUSTY WINDS,
SMALL HAIL AND BRIEF HEAVY DOWNPOURS.

WIND: GUSTS OF 45 TO 50 MPH ARE POSSIBLE WITH THE STRONGEST
THUNDERSTORMS THIS AFTERNOON AND EVENING.

HAIL: SMALL HAIL UP TO DIME SIZE IS POSSIBLE WITH THE STRONGEST
THUNDERSTORMS THROUGH THE EVENING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THERE WILL BE A CHANCE OF AFTERNOON THUNDERSTORMS WEDNESDAY AND
THURSDAY WITH LESS ACTIVITY EXPECTED LATER IN THE WEEK.

.SPOTTER INFORMATION STATEMENT...

WIDESPREAD SPOTTER ACTIVATION IS NOT ANTICIPATED, HOWEVER
INDIVIDUAL SPOTTERS ARE ENCOURAGED TO REPORT HIGH WIND, HAIL AND
FLOODING TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
MIAMI.

FOR MORE INFORMATION...VISIT THE NATIONAL WEATHER SERVICE IN
MIAMI WEBSITE AT WWW.WEATHER.GOV/MIAMI.