176
FXUS62 KKEY 161940
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
240 PM EST MON DEC 16 2024
..NEW DISCUSSION, MARINE, AVIATION
DISCUSSION
ISSUED AT 242 PM EST MON DEC 16 2024
A VERY PECULIAR WEATHER PATTERN DEVELOPED OVER THE FLORIDA KEYS
OVER THE PRIOR WEEKEND. A HIGH PRESSURE SYSTEM LOCATED OFFSHORE
OF NEW ENGLAND LAST NIGHT WOULD TYPICALLY BE THE DOMINANT FEATURE
FOR KEYS WEATHER. INSTEAD, AN INVERTED TROUGH OBSERVED NORTH
NORTHWEST OF THE TURKS AND CAICOS ISLANDS WILL BE THE PRIMARY
FEATURE OF INTEREST FOR TONIGHT'S WEATHER. BREEZES ARE SLACKENING
AS THE TROUGH APPROACHES THE KEYS AND THE HIGH SHIFTS FURTHER INTO
THE NORTH ATLANTIC. HOWEVER, THE INVERTED TROUGH WILL BRING A
SHALLOW PLUME OF TROPICAL MOISTURE TO THE FLORIDA KEYS ALONG WITH
AN INCREASE IN CAPE. THE MORNING PACKAGE ADDED THUNDERSTORMS
TONIGHT, A DECISION FURTHER SUPPORTED BY DECREASING HEIGHTS AS
MEASURED BY THE 12Z KKEY SOUNDING AND A LOWER FREEZING LEVEL.
OVERNIGHT, EXPECTING MODERATE TO FRESH BREEZES ACROSS THE CWA
WITH AN INCREASE TO 40 PERCENT POPS WITH A SLIGHT CHANCE OF
THUNDERSTORMS.
WESTWARD MOVEMENT OF THE INVERTED TROUGH WILL DICTATE CONDITIONS
OVER THE FLORIDA KEYS THROUGH WEDNESDAY. WHILE GOES EAST
OBSERVATIONS INDICATE THE TROUGH IS CURRENTLY MOVING QUICKLY,
A BROAD RIDGE IS PROGGED TO DEVELOP OVER THE EASTERN UNITED STATES
BY WEDNESDAY. MODEL ENSEMBLES SHOW THE TROUGH SLOWING AS IT NEARS
THE BAHAMAS OVER THE NEXT TWO DAYS. THE RESULT WOULD BE MODERATE
BREEZES, A CHANCE OF SHOWERS, AND A SLIGHT CHANCE OF THUNDERSTORMS
THROUGH WEDNESDAY; HOWEVER, EXACT DETAILS WILL DEPEND ON HOW
EXACTLY THE INVERTED TROUGH DEVELOPS AND MOVES. IN ESSENCE, A
SURPRISING BIT OF SPRING WEATHER FOR DECEMBER.
SPRING IN DECEMBER WILL COME TO A RATHER RAPID END LATE IN THE
WEEK. A RAPIDLY MOVING COLD FRONT IS PROGGED TO MOVE ACROSS THE
GULF OF MEXICO AND WASH OUT THE MOISTURE PLUME FROM THE INVERTED
TROUGH. WHILE CONTINENTAL, SINKING AIR WILL SHIFT ACROSS THE KEYS
AT THE END OF THE WEEK, THE FRONT IS PROGGED TO BE RATHER ANEMIC
AND ENSEMBLE MODELS CURRENTLY DO NOT SHOW LOW TEMPERATURES
DROPPING INTO THE LOW 60S BEFORE THE WEEKEND. A SECOND,
REINFORCING FRONT IS FORECAST TO SURGE SOUTH IN ITS WAKE OVER THE
WEEKEND, AND THAT FRONT WOULD BE CAPABLE OF DROPPING DEW POINTS
INTO THE 50S. OVERALL, THOSE WHO WANT SHOWERS AND A POSSIBLE
THUNDERSTORM SHOULD HAVE THEIR WISHES GRANTED BEFORE KEY WEST
WINTER RETURNS OVER THE WEEKEND.
MARINE
ISSUED AT 242 PM EST MON DEC 16 2024
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE STRAITS OF
FLORIDA THROUGH THIS EVENING. SMALL CRAFT SHOULD EXERCISE (SCEC)
UNTIL WINDS DECREASE IS HEADLINED FOR HAWK CHANNEL TONIGHT. FROM
SYNOPSIS, AN INVERTED TROUGH LOCATED NORTH NORTHWEST OF THE TURKS
AND CAICOS ISLANDS ARE SUSTAINING FRESH TO STRONG BREEZES OVER THE
FLORIDA STRAITS THIS EVENING, BUT BREEZES WILL SLACKEN TO
MODERATE AFTER SUNSET AS THE TROUGH NEARS THE BAHAMAS AND A HIGH
PRESSURE SYSTEM IN THE NORTH ATLANTIC MOVES FURTHER EAST. THE
TROUGH WILL ALSO BRING A PLUME OF SHALLOW TROPICAL MOISTURE TO THE
FLORIDA KEYS COASTAL WATERS, SUPPORTING ISOLATED TO SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS THROUGH MID WEEK. LATE IN THE
WEEK, A WEAK COLD FRONT IS FORECAST TO MOVE SOUTH FROM THE GULF OF
MEXICO AND REGENERATE MODERATE TO FRESH BREEZES FOR THE WEEKEND.
AVIATION
(15Z TAFS)
ISSUED AT 242 PM EST MON DEC 16 2024
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT EYW AND MTH FOR THE
REST OF TODAY, BUT CONTINUED PASSING BOUTS OF SHALLOW SHOWERS MAY
OCCASIONALLY RESULT IN SUB-VFR CIGS, ESPECIALLY IN THE VICINITY OF
MARATHON. IMPACTS ARE EXPECTED TO BE BRIEF AND MINIMAL. ERGO, NO
SPECIFIC MENTION IN THE TAFS IS REQUIRED AT THIS TIME. NEAR
SURFACE WINDS WILL BE OUT OF THE NORTHEAST AT NEAR 10 KNOTS WITH
FREQUENT GUSTS UP TO NEAR 20 KNOTS BEFORE SLACKENING LATER
TONIGHT.
CLIMATE
ON THIS DAY IN 1968, A DAILY RECORD COLD MAXIMUM TEMPERATURE OF
60F WAS LAST RECORDED IN KEY WEST. ON THE SAME DAY, A DAILY COLD
MAXIMUM TEMPERATURE OF 59F WAS MEASURED IN MARATHON. TEMPERATURE
RECORDS FOR KEY WEST AND MARATHON DATE BACK TO 1872 AND 1950,
RESPECTIVELY.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 71 79 71 79 / 30 20 20 20
MARATHON 72 79 72 79 / 30 30 30 30
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR GMZ052>055-
072>075.
PUBLIC/MARINE/FIRE...AJP
AVIATION/NOWCASTS....JAM
DATA ACQUISITION.....JAM
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