286
FXUS62 KKEY 180926
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
426 AM EST WED DEC 18 2024
..NEW DISCUSSION, MARINE, AVIATION
DISCUSSION
ISSUED AT 425 AM EST WED DEC 18 2024
IT IS A WARM AND HUMID MID DECEMBER NIGHT ACROSS THE FLORIDA KEYS.
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS THE NORTH ATLANTIC
WITH THE WESTERN PERIPHERY OF THIS RIDGE EXTENDING WEST INTO THE
FLORIDA KEYS. THIS IS PROMOTING NORTHEAST TO EAST BREEZES OF 10 TO
15 KNOTS SOUTH OF THE ISLAND CHAIN WITH 5 TO 10 KNOTS NORTH OF THE
CHAIN. ISLAND COMMUNITIES ARE OBSERVING NORTHEAST TO EAST BREEZES
OF 5 TO 10 MPH. IN ADDITION, MOISTURE CONTINUES TO STREAM INTO THE
KEYS DUE TO THE EASTERLY FLOW ALONG THE SOUTHERN PERIPHERY OF THE
RIDGE. DUE TO THIS, KBYX RADAR HAS BEEN DETECTING ISOLATED LIGHT
SHOWERS/SPRINKLES, MAINLY ACROSS THE STRAITS OF FLORIDA FOR MUCH
OF THE NIGHT. TEMPERATURES ALONG THE ISLAND CHAIN ARE IN THE LOWER
TO MID 70S WITH DEW POINTS IN THE LOWER 70S.
FORECAST
THE AFOREMENTIONED HIGH PRESSURE IS EXPECTED TO CONTINUE TO
SLOWLY MOVE EASTWARD FARTHER OUT INTO THE ATLANTIC TODAY AND
TONIGHT. AS IT DOES SO, IT WILL CONTINUE TO LOOSEN ITS GRIP ON THE
REGION RESULTING IN FURTHER SLACKENING BREEZES. THE HIGH IS
EXPECTED TO HOLD JUST ENOUGH OF A GRIP, HOWEVER, TO ALLOW MOISTURE
TO CONTINUE TO BE FUNNELED INTO THE KEYS KEEPING SLIGHT CHANCES
IN THE FORECAST FOR TODAY. A SLIGHT UPTICK TO THE MOISTURE IS
EXPECTED TONIGHT RESULTING IN CHANCES OF RAIN (30%).
THEN, AN POSITIVELY TILTED UPPER LEVEL TROUGH CURRENTLY DIVING
SOUTHEASTWARD OVER THE SOUTH-CENTRAL PLAINS THIS MORNING WILL
CONTINUE MOVING TOWARDS THE NORTH GULF COAST. THE TROUGH IS
EXPECTED TO REACH THE NORTH GULF COAST BY THIS EVENING. AS THE
TROUGH SWINGS EASTWARD ACROSS THE NORTH GULF COAST AND FLORIDA, IT
IS EXPECTED TO BECOME NEGATIVELY TILTED THURSDAY. AT THE SURFACE,
A WEAK FRONT IS EXPECTED TO PRESS THROUGH THE KEYS AS A RESULT
SOMETIME LATE THURSDAY OR THURSDAY EVENING. THIS WILL RESULT IN
FRESHENING NORTHERLY BREEZES ALONG WITH MUCH DRIER AIR MOVING IN
BEHIND IT. THEREFORE, TIMING WAS INTRODUCED FOR THE RAIN CHANCES
THURSDAY EVENING WITH IT RAPIDLY DRYING OUT AFTER MIDNIGHT.
ANOTHER MORE POTENT UPPER LEVEL TROUGH WILL SWING ACROSS THE
TENNESSEE VALLEY AND THE NORTHEAST FRIDAY WHICH WILL SEND A
SECONDARY FRONT AT THE SURFACE THROUGH THE KEYS FURTHER DROPPING
THE DEW POINTS AND TEMPERATURES. TEMPERATURES ON SATURDAY ARE
EXPECTED TO BE IN THE UPPER 60S WITH OVERNIGHT LOWS IN THE LOWER
60S WITH POTENTIALLY THE UPPER 50S FOR THE UPPER KEYS SATURDAY
NIGHT. DEW POINTS WILL ALSO DROP INTO THE 50S PERHAPS EVEN THE MID
TO UPPER 40S. WINTER WILL MAKE A RETURN! ALSO, PLENTY OF DRY AIR
WILL BE IN PLACE RESULTING IN A DRY FORECAST FRIDAY THROUGH
SUNDAY NIGHT.
IN THE WAKE OF THE SECONDARY FRONT, A LARGE AND STRONG HIGH
PRESSURE BUILDS ACROSS THE EASTERN UNITED STATES OVER THE WEEKEND
INTO EARLY NEXT WEEK WITH MOST ENSEMBLE AND DETERMINISTIC GUIDANCE
ON BOARD WITH THIS SOLUTION. THIS WILL PROMOTE FRESHENING
NORTHEAST TO EAST BREEZES WITH ANOTHER POTENTIALLY LENGTHY BLOW
EXPECTED AS A HEALTHY PRESSURE GRADIENT DEVELOPS. INITIALLY,
MOISTURE IS EXPECTED TO REMAIN SCARCE, BUT THIS IS EXPECTED TO
RAPIDLY CHANGE AS MOISTURE QUICKLY INCREASES AT 850 MB. ANY
SHOWERS WILL YET AGAIN REMAIN SHALLOW AND QUICK MOVING IN THE
EASTERLIES PRODUCING MINOR RAINFALL AMOUNTS GENERALLY UNDER A
TENTH OF AN INCH. THIS MAY BE JUST ENOUGH TO CREATE A WET LEAD-UP
TO CHRISTMAS WITH THE WET REGIME AND WINDY CONDITIONS POTENTIALLY
CONTINUING INTO THE CHRISTMAS HOLIDAY.
MARINE
ISSUED AT 425 AM EST WED DEC 18 2024
THERE ARE CURRENTLY NO WATCHES, WARNINGS, OR ADVISORIES IN EFFECT
ACROSS THE FLORIDA KEYS COASTAL WATERS. FROM SYNOPSIS, HIGH
PRESSURE OVER THE NORTH ATLANTIC WILL CONTINUE SLIDING FARTHER
EAST LOOSENING ITS GRIP ACROSS THE FLORIDA KEYS. AS A RESULT,
GENTLE TO MODERATE NORTHEAST TO EAST BREEZES THIS MORNING WILL
CONTINUE TO FURTHER SLACKEN DURING THE DAY. BREEZES WILL FURTHER
SLACKEN TONIGHT AND THURSDAY BECOMING LIGHT TO GENTLE AHEAD OF AN
APPROACHING WEAK FRONT. THE WEAK FRONT IS ANTICIPATED TO PRESS
THROUGH THE KEYS SOMETIME LATE THURSDAY RESULTING IN FRESHENING
NORTHERLY BREEZES. A SECONDARY FRONT IS EXPECTED TO PRESS THROUGH
THE KEYS LATE FRIDAY REINFORCING THE PREVIOUS FRONT.
AVIATION
(06Z TAFS)
ISSUED AT 425 AM EST WED DEC 18 2024
VFR CONDITIONS WILL PREVAIL AT THE EYW AND MTH TERMINALS THROUGH
WEDNESDAY EVENING. ISOLATED TO WIDELY SCATTERED SHOWERS MAY
BRIEFLY IMPACT EITHER TERMINAL THROUGH THE MID MORNING HOURS, AND
HAVE INCLUDED VCSH, BUT THE PROBABILITY OF SUB-VFR CONDITIONS IS
TOO LOW TO MENTION IN THE TAFS. SURFACE WINDS WILL REMAIN FROM THE
NORTHEAST TO EAST AT 4 TO 8 KNOTS.
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...MJV
AVIATION/NOWCASTS....JACOBSON
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