Freeze Warning 4, NWS Miami, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
505 AM EST TUE JAN 5 2010

.DISCUSSION...A LARGE AND DEEP UPPER TROF REMAINS ACROSS THE
EASTERN CONUS THIS MORNING WHILE A RIDGE OF COLD, DRY, ARCTIC HIGH
PRESSURE REMAINS OVER CENTRAL SECTIONS OF THE COUNTRY. THE SUB
TROPICAL JET ALSO CONTINUES TO BE ACTIVE TRANSPORTING MID AND HIGH
LVL MOISTURE ACROSS THE NW CARIBBEAN, THE SOUTHERN GULF, AND S FL.
THE SURFACE RIDGE. MODELS CONTINUE TO AGREE THAT THE LARGE UPPER
TROF WILL REMAIN IN PLACE THROUGH THE PERIOD, WHILE MULTIPLE
IMPULSES ROUND THE BASE OF THE TROF CONTINUOUSLY REINFORCING THE
TROF. ONE SUCH SHORT WV IS CURRENTLY MOVING OFF THE SE ATLANTIC
COAST WHILE YET ANOTHER SURGE IN ARCTIC AIR SPILLS SOUTH AND INTO
S FL... OF COURSE WHILE THIS OCCUR THE VERY COLD AIRMASS IS
PARTIALLY MOVING ACROSS THE NW GULF WATERS CREATING SLIGHTLY
UNSTABLE CONDITIONS AND INCREASING MOISTURE TO THE WEST HALF OF THE
FL PENINSULA. THIS INC IN CLOUD COVER AND EVEN A FEW SPRINKLES
TO VERY LIGHT SHRA HAS HELPED KEEP TEMPS FROM FALLING TOO FAR ~
JUST TO SLIGHTLY ABOVE FREEZING. OPTED NOT TO CANCEL THE FREEZE
WARNING SINCE ISOLATED AREAS ARE AT 33 TO 35 AND THERE IS STILL
TIME TO REACH THAT MAGICAL NUMBER OF 32. THE SURGE OF COLD AIR IS
EXPECTED TO HAVE SETTLED ACROSS S FL TONIGHT WITH MUCH OF THE COLD
COVER CLEARED OUT (FINGERS CROSSED). ATTM PULLED THE TRIGGER ON
THE FREEZE WARNING FOR TONIGHT ACROSS MUCH OF THE INTERIOR... HELD
OFF ON COASTAL PALM BEACH, AND METRO BROWARD AND MIAMI-DADE
COUNTIES AS UNCERTAINTIES REMAIN IN THE FORECAST, BUT VERY CLOSE
TO FREEZING IN THE WESTERN SECTIONS OF THESE ZONES. WILL LET DAY
SHIFT TAKE A LOOK.

WED AFTERNOON THROUGH THURS... A BRIEF BREAK WILL OCCUR IN THE
REINFORCING FRONTS AND TEMPS AND MOISTURE WILL SLOWLY AND SLIGHTLY
MODERATE. A VERY COLD AIRMASS (1054MB HIGH) WILL MOVE OUT OF
CANADA AND INTO MONTANA... HEADED SOUTH. AHEAD OF THIS RIDGE, A
STRONG SHORT WAVE WILL DROP SE INTO THE PLAINS.

THURS NIGHT THROUGH FRI EVENING... THE AFOREMENTIONED S WV WILL
MOVE INTO THE MID TO LOWER MS VALLEY WITH MID LVL MOISTURE
INCREASING OVER S FL COURTESY OF THE SUB TROPICAL JET AHEAD OF THE
SHORT WAVE. A WEAK SURFACE LOW MAY ALSO DEVELOP IN THE NORTHERN
GULF AND MOVE EAST ACROSS N OR CENTRAL FL. AREAS OF LIGHT RAIN MAY
RESULT... ALTHOUGH MOST AREAS WILL BE MORE IN THE SPRINKLE VARIETY
AS DRY AIR AT THE SURFACE MAY HAVE A DIFFICULT TIME WORKING OUT.

FRI NIGHT THROUGH THE WEEK... THE COLD AIRMASS/STRONG RIDGE WILL
SETTLE ACROSS THE SOUTHEASTERN STATES AND PLUNGE MORE COLD AIR
SOUTH WITH A RETURN OF FREEZING TEMPS EXPECTED, ESPECIALLY OVER
THE INTERIOR.

&&

.MARINE...ANOTHER SURGE OF ARCTIC AIR IS MOVING INTO THE AREA THIS
MORNING AND WINDS AND SEAS WILL INCREASE THIS MORNING TO AROUND 20
KTS AND INTO THE 6 TO 8 FEET RANGE IN THE GULF STREAM AN THE GULF
WATERS BEYOND 40 NM...AND THE LAKE AS FAR AS THE WINDS GO. AS THIS
SURGE MOVES FARTHER AWAY WINDS AND SEAS WILL GRADUALLY DECREASE
THIS EVENING AND TONIGHT. WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SCA CRITERIA FROM EARLY WED MORN THROUGH FRI MORNING...THEN
ANOTHER COLD FRONT WILL SWEEP THROUGH WIND ROUGH MARINE CONDITIONS
EXPECTED FRIDAY THROUGH THIS WEEKEND.

&&

.FIRE WEATHER...A COLD AND DRY ARCTIC AIRMASS CONTINUES TO SPILL
INTO THE REGION ON THE NORTH TO NORTHWEST FLOW THIS MORNING...
HOWEVER A BIT OF GULF MOISTURE IS ALSO WORKING IN. THE GULF
MOISTURE SHOULD BE SIGNIFICANT ENOUGH TO HOLD MUCH OF THE WEST HALF
OF S FL OUT OF RFW CRITERIA, BUT ALONG THE LAKE REGION AND ACROSS
METRO AND COASTAL PALM BEACH, RHS MAY FALL INTO THE LOW 30S FOR A
FEW HOURS. ATTM DECIDED TO CANCEL THE WATCH FOR COLLIER, BROWARD,
AND MIAMI-DADE WHERE CLOUD COVER MAY AND INCREASED LOW LVL
MOISTURE MAY BE ENOUGH TO EITHER KEEP THE DURATION OF SUB 35
PERCENT RH LOW OR TO NONE AT ALL. THE N TO NW FLOW WILL CONTINUE
WED WITH SOME GULF MOISTURE WORKING INTO THE GULF COASTAL AREAS
AGAIN... HENCE THE WATCH FOR ALL AREAS BUT COASTAL COLLIER,
MAINLAND MONROE, AND FAR SOUTH DADE. MOISTURE WILL BEGIN TO
INCREASE SLIGHTLY THURS, HOWEVER RHS WILL STILL FALL TO AROUND 35
PERCENT IN THE AFTERNOON FOR A COUPLE HOURS.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  55  31  57  38 / -  0 0 0
FORT LAUDERDALE  59  38  60  43 / -  0 0 0
MIAMI            60  37  60  42 / -  0 0 0
NAPLES           55  37  58  39 / 10 0 0 0

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...FREEZE WARNING FROM 11 PM THIS EVENING TO 10 AM EST WEDNESDAY
     FOR FLZ063-FLZ066-FLZ067-FLZ068-FLZ070-FLZ071-FLZ073.

     FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
     EVENING FOR FLZ063-FLZ066-FLZ067-FLZ068-FLZ070-FLZ071-
     FLZ072-FLZ073-FLZ074-FLZ168-FLZ172-FLZ173.

     FREEZE WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
     FLZ072-FLZ074-FLZ168.

     WIND CHILL ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR FLZ068-
     FLZ072-FLZ168-FLZ172.

     FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING
     FOR FLZ063-FLZ066.

     RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 6 PM EST THIS
     EVENING FOR FLZ063-FLZ066-FLZ067-FLZ068-FLZ168.

     FREEZE WARNING UNTIL 8 AM EST THIS MORNING FOR FLZ063-FLZ066-
     FLZ067.

AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ610-
     AMZ650-AMZ651-AMZ670-AMZ671.

GM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR GMZ676.

&&

LONG TERM...04/TINGLER
SHORT TERM/AVIATION...17/ERA

HAZARDOUS WEATHER OUTLOOK FOR SOUTH FLORIDA...UPDATED
NATIONAL WEATHER SERVICE MIAMI FL
309 PM EST MON JAN 4 2010

FLZ063-066>075-168-172>174-051100-
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-
309 PM EST MON JAN 4 2010

...FREEZE WARNING LAKE OKEECHOBEE REGION TONIGHT...
...WIND CHILL ADVISORY PALM BEACH, BROWARD METRO TONIGHT...
...FREEZE WATCH MUCH OF SOUTH FLORIDA TUESDAY NIGHT...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

TEMPERATURES: LOW TEMPERATURES TONIGHT COULD DROP TO AROUND OR
JUST BELOW FREEZING ACROSS PARTS OF THE INTERIOR. THE GREATEST
THREAT IS OVER THE LAKE OKEECHOBEE REGION. WIND CHILLS BELOW 35
DEGREES ARE POSSIBLE ACROSS THE INTERIOR, METRO PALM BEACH AND
METRO BROWARD COUNTIES WHERE A WIND CHILL ADVISORY IS IN EFFECT.
WIND CHILLS ACROSS METRO MIAMI AND THE NAPLES AREAS WILL RANGE
FROM 35 TO 40 DEGREES.

WAVES: SEAS OF 6 TO 7 FEET ARE POSSIBLE FOR NORTHERN PARTS OF THE
GULF STREAM AS WELL AS THE OFFSHORE GULF WATERS. STRONG WINDS WILL
COMBINE WITH THESE SEAS TO CREATE HAZARDOUS MARINE CONDITIONS.

WIND: WINDS OF 20 TO 25 KNOTS WILL BE POSSIBLE ACROSS THE ATLANTIC
WATERS OVERNIGHT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

FREEZING TEMPERATURES ARE POSSIBLE AGAIN THROUGH THE MIDDLE OF THE
WEEK ACROSS PARTS OF SOUTH FLORIDA. A FREEZE WATCH IS IN EFFECT
FOR GLADES, HENDRY, AND INLAND PORTIONS OF COLLIER, PALM BEACH,
MIAMI- DADE AND BROWARD COUNTIES TUESDAY NIGHT ALONG WITH METRO
AND COASTAL PALM BEACH COUNTY, METRO BROWARD AND METRO MIAMI-DADE
COUNTIES. FREEZING TEMPERATURES MAY BE POSSIBLE FOR A BRIEF TIME
IN THE LAKE OKEECHOBEE REGION WEDNESDAY NIGHT.

FOR THE REST OF THE METROPOLITAN AREAS, LOWS IN THE UPPER 30S TO
THE 40S ARE EXPECTED, LASTING ALL THE WAY THROUGH THE MIDDLE PART
OF THE WEEK.

THERE MAY BE A BRIEF WARMING TREND BY THURSDAY AND FRIDAY, BUT ANOTHER
STRONG COLD FRONT IS EXPECTED TO PASS LATE ON FRIDAY WITH A
RETURN TO MUCH BELOW NORMAL TEMPERATURES BY SATURDAY. FREEZING
TEMPERATURES WILL AGAIN BE POSSIBLE OVER PORTIONS OF INTERIOR
SOUTH FLORIDA NEXT WEEKEND.

STAY TUNED TO THE LATEST FORECAST UPDATES ON THIS COLD WEATHER
EPISODE ALONG WITH POSSIBLE ADDITIONAL FREEZE WATCHES AND POSSIBLE
FREEZE WARNINGS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

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

STRASSBERG