Dense Fog in Florida, January 22, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
346 AM EST SAT JAN 22 2011

.SHORT TERM...LATEST SFC OBS INDICATE A COLD FRONT LOCATED ACROSS
CENTRAL FLORIDA AS SHOWN BY THE RAPID DECREASE IN DEW POINTS
BEHIND IT. A LARGE AREA OF STRATUS ASSOCIATED WITH THIS SYSTEM
COVERED MOST OF THE PENINSULA FROM JUST SOUTH OF LAKE OKEECHOBEE
AREA NORTHWARD. WL EXPECTED THESE LOW CLOUDS TO SPREAD SOUTH AND
COVER MOST OF SOUTH FLORIDA AS THE FRONT MOVES SOUTH TODAY. THIS
COULD RESULT IN LOWER MAX AFTERNOON TEMPS THAN BOTH, MET MOS AND
MAV MOS ARE FORECASTING...AND SO DECIDED TO GO A COUPLES OF
DEGREES LOWER WITH MAX TEMPS REMAINING MOSTLY IN THE M/U 60S AND
BARELY MAKING IT TO AROUND 70, IF AT ALL, OVER EXTREME SOUTHEAST
SECTIONS. THE FRONT SHOULD MOVE SOUTHEAST OF THE AREA LATER THIS
AFTERNOON WITH RAPID CLEARING BY THIS EVENING AND OVERNIGHT. A
MUCH COLDER AIR MASS WILL USHER IN AS A SURFACE HIGH OVER SE U.S.
MOVES SOUTH TO NE GULF OF MEX. LATEST GUIDANCE SUGGEST MIN TEMPS
SUNDAY MORNING FALLING TO NEAR OR AROUND FREEZING OVER GLADES AND
HENDRY COUNTIES TO NEAR 40 WEST COAST AND LOW/MID 40S EAST COAST.
ALTHOUGH CONFIDENCE IS HIGHER THAN 24 HRS AGO, UNCERTAINTIES STILL
EXITS DUE TO RECENT FLIP FLOPPING OF THE MODELS. WITH 24 HRS STILL
FOR THIS EVENT, WL LET DAY SHIFT EXAMINE LATEST GUIDANCE AND OBS
TREND BEFORE DECIDING WHETHER UPDATE THE CURRENT FREEZE WATCH FOR
GLADES/HENDRY TO A WARNING OR NOT. THERE IS ALSO A POSSIBILITY OF
HAVING TO INCLUDE NORTHERN PORTIONS OF COLLIER COUNTY IN THIS
DECISION. IN ADDITION...WINDCHILL VALUES COULD FALL TO L/M 30S
ACROSS AREAS WEST OF LAKE OKEECHOBEE AND M/U 30S OVER THE REST OF
THE INTERIOR. THE CAVEAT BEING DECOUPLING OF THE LOWER ATMOSPHERE
OVER INLAND AREAS...IN WHICH CASE SFC WINDS COULD DIMINISH FASTER
THAN CURRENTLY FORECAST, THEREBY LESSENING THE CHILL EFFECT.

MONDAY THROUGH TUESDAY...RAPID WARM UP EXPECTED AS THE SURFACE
HIGH MOVES EASTWARD TO THE WESTERN ATLANTIC AND WINDS SHIFT TO
MORE NE TO E.

WEDNESDAY THROUGH FRIDAY...ANOTHER DIVE OF THE POLAR JET OVER ERN
U.S. WL PUSH ANOTHER COLD FRONT DOWN THE PENINSULA AND THROUGH THE
LOCAL AREA LATE TUE NIGHT/EARLY WEDNESDAY MORNING WITH ANOTHER
SURGE OF COLD AIR AFFECTING THE AREA THROUGH THE END OF THE WORK WEEK.

&&

.MARINE...SFC WINDS WILL RAPIDLY INCREASE AS THE FRONT MOVES
THROUGH THE AREA WATERS TODAY WITH WIND SPEEDS INCREASING TO ABOVE
20 KTS OVER THE ATLANTIC AND GULF WATERS LATER THIS MORNING AND
REMAINING ABOVE 20 KTS THROUGH TONIGHT. SEAS WILL ALSO RESPOND BY
BUILDING TO 7 TO 8 FEET OVER THE GULF WATERS AND UP TO 7 FEET OVER
THE ATLANTIC WATERS. WL ISSUE A SMALL CRAFT ADV FOR THESE WATERS
THIS MORNING AND ALSO A CAUTION STATEMENT FOR LAKE OKEECHOBEE FOR
SLIGHTLY LOWER WIND SPEEDS. MARINE CONDITIONS SHOULD IMPROVE
SIGNIFICANTLY BY THE END OF THE WEEKEND OR BEGINNING OF NEXT WEEK.

&&

.FIRE WEATHER...ALTHOUGH DEW POINTS ARE EXPECTED TO DROP TO THE
UPPER 20S TO MID 30S BY SUNDAY MORNING, A SHIFT IN THE SFC WINDS
TO MORE NE BY AFTERNOON WILL ALLOW DEW POINTS TO BOUNCE BACK INTO
THE UPPER 30S/MID 40S BY EARLY AFTERNOON...AND ALTHOUGH RH VALUES
MAY FALL TO AROUND 35% OVER WESTERN INTERIOR...THIS MAY LIMIT THE
DURATION TO ONLY A COUPLE OF HOURS. MIN RH SHOULD REMAIN ABOVE
CRITICAL LEVELS THEREAFTER.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  68  42  65  52 / 20 -  -  10
FORT LAUDERDALE  70  44  68  54 / 20 -  -  10
MIAMI            70  46  68  59 / 20 -  -  10
NAPLES           62  39  63  46 / 20 -  -  -

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR GLADES-
     HENDRY.

AM...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 4 AM EST SUNDAY
     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-WATERS FROM DEERFIELD BEACH TO OCEAN
     REEF, FL EXTENDING FROM 20 NM TO 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 FROM 7 AM THIS MORNING TO 4 AM EST SUNDAY
     FOR COASTAL WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT
     20 NM-COASTAL WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE,
     FL OUT 20 NM-GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH,
     FL EXTENDING FROM 20 TO 60 NM.

&&

DISCUSSION/MARINE...47/RGH
AVIATION/RADAR/FIRE...04/AT

HAZARDOUS WEATHER OUTLOOK FOR SOUTH FLORIDA
NATIONAL WEATHER SERVICE MIAMI FL
530 AM EST SAT JAN 22 2011

FLZ063-066>075-168-172>174-230530-
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-
530 AM EST SAT JAN 22 2011

...DENSE FOG ADVISORY IS IN EFFECT THROUGH 9 AM...
...HAZARDOUS MARINE CONDITIONS THROUGH LATE TONIGHT...
...FREEZING TEMPERATURES POSSIBLE NORTH AND WEST OF LAKE OKEECHOBEE...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...TODAY AND TONIGHT

VISIBILITY: A DENSE FOG ADVISORY IS IN EFFECT FOR PORTIONS OF SOUTH
FLORIDA THROUGH 9 AM. SOME LOCATIONS WILL SEE RESTRICTED VISIBILITY
THROUGH 9AM DUE TO FOG WITH VISIBILITIES LESS THAN ONE QUARTER OF A
MILE.

WIND: NORTHWEST WINDS OF 20 TO 25 KNOTS WILL OCCUR ACROSS THE
COASTAL ATLANTIC AND GULF OF MEXICO WATERS TODAY.

WAVES: STRONG NORTHWEST WINDS WILL ALLOW SEAS TO BUILD INTO THE 7
TO 8 FEET RANGE IN THE GULF STREAM AND GULF OF MEXICO WATERS
BEYOND 20 NAUTICAL MILES FROM SHORE. A SMALL CRAFT ADVISORY IS
CURRENTLY IN EFFECT FOR HAZARDOUS MARINE CONDITIONS.

TEMPERATURES: LATE TONIGHT AND INTO SUNDAY MORNING TEMPERATURES
WILL FALL INTO THE UPPER 20S TO MID 30S ACROSS GLADES AND HENDRY
COUNTIES AND MUCH OF INLAND SECTIONS OF COLLIER COUNTY. ALONG THE
GULF AND ATLANTIC COAST TEMPERATURES WILL BE IN THE UPPER 30S TO
MID 40S.

RIP CURRENTS: NORTHWEST WINDS OF NEAR 20 MPH WILL PRODUCE A
MODERATE RISK OF RIP CURRENTS ALONG THE COLLIER COUNTY COAST FROM
MARCO ISLAND NORTHWARD.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SUNDAY WILL START OF CHILLY ACROSS SOUTH FLORIDA WITH TEMPERATURES
AROUND OR A FEW DEGREES BELOW THE FREEZING MARK FROM AROUND IMMOKALEE
IN THE NORTHERN SECTIONS OF COLLIER COUNTY TO POINTS NORTHWARD ACROSS
GLADES AND HENDRY COUNTIES. SUNDAY MORNING LOW TEMPERATURES WILL
BE IN THE MID 30S AND 40S ACROSS THE REST OF SOUTH FLORIDA.
TEMPERATURES WILL BE AROUND 10 DEGREES WARMER DURING MONDAY MORNING.

NO OTHER HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.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.