Area Forecast Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KKEY 241956
AFDKEY

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
256 PM EST WED DEC 24 2014

.DISCUSSION...
CURRENTLY - A SURFACE LOW PRESSURE SYSTEM IS RACING NORTHWARD ALONG
THE APPALACHIANS. AN ASSOCIATED COLD FRONT IS MOVING SOUTHEASTWARD
THROUGH THE CENTRAL GULF OF MEXICO. RELATIVELY FAST AND CONFLUENT LOW
LEVEL FLOW AROUND THE SOUTHERN PERIPHERY OF THIS LOW HAS RESULTED IN
SIGNIFICANT DESTABILIZATION OF LOCAL ENVIRONMENT TODAY...AND A SWATH
OF SHOWERS WITH EMBEDDED THUNDERSTORMS IS WORKING ITS WAY NORTH
NORTHEASTWARD ACROSS THE LOWER KEYS AND SURROUNDING NEARSHORE AND
WATERS. HIGH CLOUDS SPREADING RAPIDLY NORTHEASTWARD FROM THE
CONVECTION HAS CLOUDIED SKIES KEYS WIDE.

FORECAST - AFTER THE BAND OF SHOWERS AND THUNDERSTORMS MOVE THROUGH
THE KEYS...THE KEYS ARE LIKELY IN STORE FOR A BREAK. THE SURFACE LOW
OVER THE APPALACHIANS IS MOVING FURTHER AWAY FROM THE KEYS...AND
CONFLUENT FLOW AT THE LOWEST LEVELS...SUPPORTIVE OF CONVECTIVE
ACTIVITY...WILL BE WEAKENING OVER THE NEXT 12 HOURS. WITH THAT
SAID...A ROUND OR TWO OF ADDITIONAL SHOWER ACTIVITY WILL BE POSSIBLE
AHEAD OF THE COLD FRONT...WHICH IS EXPECTED TO REACH THE KEYS AROUND
SUNRISE TOMORROW. EXPECT ABOVE NORMAL TEMPS AND HUMIDITY TONIGHT DUE
TO THE SOUTHERLY FLOW TURNING MORE WESTERLY TOWARDS DAY BREAK.

WIND WILL TURN NORTHWEST TO NORTH IN WAKE OF THE COLD FRONT. THE
COMBINATION OF A MORNING COLD FRONT ARRIVAL...AND A 1025MB HIGH
SLIDING NORTHEASTWARD FROM THE GULF OF MEXICO...INTO THE SOUTHEASTERN
UNITED STATES MEANS THERE WILL NOT BE MUCH OF A COLD AIR PUSH. WINDS
WILL STRUGGLE TO PICK UP IN WAKE OF THE COLD FRONT. THE RAPID
NORTHEASTWARD MOTION OF THE HIGH WILL QUICKLY TURN WINDS
NORTHEASTWARD THURSDAY NIGHT...AND MORE EASTERLY FRIDAY. THE QUICK
VEERING WINDS AND LACK OF SUBSTANTIAL COLD AIR ADVECTION WILL MEAN
LOWS WILL LIKELY NOT REACH EVEN NORMAL OVERNIGHT LOWS.

THROUGH THE REMAINDER OF THE WEEK...INTO EARLY NEXT WEEK...THE HIGH
OVER THE SOUTHEASTERN UNITED STATES WILL ELONGATE EASTWARD INTO THE
ATLANTIC...KEEPING A LIGHT EASTERLY FLOW ACROSS THE KEYS.
LITTLE TREND IN TEMPERATURES IS EXPECTED...AND WILL REMAIN A FEW
DEGREES ABOVE NORMAL. HOWEVER...HUMIDITY SHOULD REMAIN
TOLERABLE...WITH DEW POINTS IN THE MID TO UPPER 60S. RAIN CHANCES
WILL BE SLIM TO NONE.

&&

.MARINE...
A COLD FRONT WILL MOVE THROUGH THE KEYS TOMORROW MORNING. AHEAD OF
THIS FRONT MODERATE SOUTH WINDS WILL GRADUALLY TURN WEST
OVERNIGHT...AND NORTHWEST TOMORROW MORNING BEHIND THE FRONT. HIGH
PRESSURE WILL THEN MOVE NORTHEASTWARD FROM THE GULF OF MEXICO INTO
THE SOUTHEASTERN UNITED STATES. LITTLE IN THE WAY OF A COLD AIR PUSH
AND A LACK LUSTER LOCAL PRESSURE GRADIENT WILL MEAN ADVISORIES ARE
NOT EXPECTED...AND ONLY A PERIOD OR TWO OF CAUTION IS EXPECTED IN
WAKE OF THE FRONTAL PASSAGE. THEREAFTER...THE HIGH WILL SPREAD
EASTWARD INTO THE ATLANTIC...GRADUALLY TURNING GENTLE BREEZES
EASTERLY WINDS EASTWARD THIS WEEKEND.

&&

.AVIATION...
VFR CONDITIONS WILL RETURN TO KEY WEST AFT 24/20Z. HOWEVER...
MVFR/TEMPO IFR AND POSSIBLE TSRA COULD REACH MARATHON AROUND
24/2015Z ONLY AFFECTING THE AIRPORT FOR APPROXIMATELY AN HOUR.
AMENDMENTS WILL BE ISSUED AS NECESSARY. SOUTH CROSSWINDS OF 15 TO 25
KNOTS EXPECTED TO CONTINUE THIS EVENING. MVFR CEILINGS COULD BE
OBSERVED FROM TIME TO TIME ACROSS BOTH TERMINALS THIS EVENING...
FOLLOWED BY A CHANCE OF SHRA...MVFR/IFR CIGS LATE THIS EVENING INTO
THURSDAY MORNING WITH THE PASSAGE OF A COLD FRONT ACROSS THE AREA.

&&

.CLIMATE...
ON THIS DATE IN KEYS WEATHER HISTORY...IN 1989...THE DAILY RECORD
LOW TEMPERATURE OF 44 DEGREES WAS RECORDED AT KEY WEST. THIS ALSO
TIED THE ALL TIME COLDEST TEMPERATURE RECORDED FOR THE MONTH OF
DECEMBER. TEMPERATURE RECORDS IN KEY WEST DATE BACK TO 1872.

&&

&&

.PRELIM POINT TEMPS/POPS...
KEY WEST  71  75  69  78 / 60 30 20 10
MARATHON  71  75  69  78 / 60 30 20 10

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&

$$

PUBLIC/MARINE.........11
AVIATION/NOWCASTS.....CLR
DATA COLLECTION.......FLING

VISIT US ON THE WEB AT WEATHER.GOV/KEY

FOLLOW US ON FACEBOOK AND TWITTER AT...

WWW.FACEBOOK.COM/NWSKEYWEST
WWW.TWITTER.COM/NWSKEYWEST





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.