173
FXUS62 KKEY 271517
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
1017 AM EST TUE JAN 27 2026
..NEW DISCUSSION, MARINE, AVIATION
KEY MESSAGES
-STRONG NORTHERLY BREEZES WILL RELAX QUITE A BIT THIS AFTERNOON AS
HIGH PRESSURE BUILDS ACROSS FLORIDA. A SMALL CRAFT ADVISORY
REMAINS UP FOR ALL KEYS WATERS AND WILL BE RETAINED THROUGH THE
AFTERNOON FOR PORTIONS OF KEYS WATERS FOR RESIDUAL SEAS.
-THE COLD AIR MASS BEHIND THE FRONT ALONG WITH A REINFORCING COLD
FRONT WILL KEEP TEMPERATURES WELL BELOW NORMAL THROUGH MID WEEK.
SOME SLIGHT MODERATION IS EXPECTED THROUGH THE BACK HALF OF THE
WORK WEEK.
-PROBABILITIES ARE INCREASING FOR HIGHER RAIN CHANCES THROUGH THE
LATER PORTION OF THE WORK WEEK DUE TO SURFACE TROUGHING
DEVELOPING ACROSS THE EASTERN FLORIDA STRAITS.
-PROBABILITIES ARE ALSO INCREASING FOR A SIGNIFICANT CHILLY WIND
SURGE THIS WEEKEND AS ANOTHER POWERFUL COLD FRONT IS EXPECTED TO
RACE SOUTHWARD THROUGH THE AREA. PORTIONS OF THE UPPER KEYS MAY
SEE WIND CHILLS IN THE 30'S.
DISCUSSION
ISSUED AT 1015 AM EST TUE JAN 27 2026
THERMOMETERS ACROSS THE FLORIDA KEYS ARE MEASURING TEMPERATURES
IN THE MID TO UPPER 50S WITH DEW POINTS IN THE 40S THIS MORNING IN
THE WAKE OF A VERY POTENT COLD FRONT. LAST NIGHT, GALE FORCE
GUSTS WERE MEASURED ACROSS THE WATERS SURROUNDING THE LOWER AND
MIDDLE KEYS. BREEZES SLACKENED AFTER SUNRISE, AND GALE WARNINGS
ARE NO LONGER IN EFFECT. LOCALS MAY ALSO NOTICE ANOTHER QUIRK IN
THE WEATHER. SKIES CLEARED OUT VERY QUICKLY AFTER SUNRISE WHILE
WINDS VEERED NORTHEASTERLY. THE MORNING 12Z SOUNDING SAMPLED A
CLASSIC POST FRONTAL ENVIRONMENT. A VERY ROBUST TEMPERATURE
INVERSION WAS PRESENT FROM 1800 TO 4000 FEET. MULTIPLE OTHER
TEMPERATURE INVERSIONS WERE PRESENT ABOVE 4000 FT, BEFORE THE
SOUNDING ENTERED A LAYER OF VERY DRY AIR ABOVE 700 MB. RAINFALL IS
NOT EXPECTED GIVEN THIS ENVIRONMENT. WINDY CONDITIONS WILL LAST
THROUGH THE REST OF THE AFTERNOON.
THERE ARE A COUPLE OF OTHER CONCERNS FOR TODAY'S WEATHER. FIRST,
WILL TEMPERATURES RECOVER? THE PATTERN ACROSS THE KEYS FOR THE
PAST WEEK HAS BEEN ONE OR TWO DAYS OF COLD WEATHER BEFORE WINDS
VEER SOUTHERLY AND TEMPS REBOUND. CURRENT GUIDANCE INDICATES THIS
SCENARIO IS VERY UNLIKELY THIS WEEK. THE WINTER STORM SYSTEM THAT
DROPPED 23 INCHES OF SNOW IN NEW BETHLEHEM, PENNSYLVANIA AND OVER
AN INCH OF ICE IN A SWATH FROM MISSISSIPPI TO SOUTH CAROLINA WAS
FOLLOWED BY A VERY LARGE AND VERY COLD ARCTIC AIR MASS. COLDER
THAN NORMAL TEMPERATURES ARE EXPECTED TO SICK AROUND FOR THE WORK
WEEK. MAKE SURE TO TAKE PRECAUTIONS IF YOU ARE NOT USED TO COOLER
TEMPERATURES AND LOWER HUMIDITY. CHECK BACK TOMORROW MORNING FOR
ANY UPDATES ABOUT THE WEEKEND FORECAST.
PREV DISCUSSION
ISSUED AT 400 AM EST TUE JAN 27 2026
THE SURFACE HIGH RESPONSIBLE FOR THE ONGOING WIND SURGE WILL
BUILD EASTWARD ALONG THE GULF COAST, ACROSS FLORIDA AND OUT INTO
THE ADJACENT ATLANTIC TODAY INTO TONIGHT. THIS ALONG WITH DAY TIME
HEATING WILL RELAX THE GRADIENT AND WINDS WILL MODERATE
CONSIDERABLY. CONTINUED COOL CONDITIONS ARE EXPECTED WITH DAY TIME
HIGHS REMAINING IN THE 60S WITH DEW POINTS HOLDING IN THE 40S.
CLOUD COVER WILL CONTINUE TO DIMINISH AND RAIN CHANCES WILL BE
NIL.
AROUND MID WEEK, A SHORTWAVE WILL SWING THROUGH THE MID LATITUDE
TROUGH ANCHORED OVER THE EASTERN UNITED STATES. THIS WILL HELP TO
PUSH A REINFORCING COLD FRONT DOWN ACROSS OUR AREA. IN ADDITION,
WINDS WILL BE HELD ROUGHLY NORTHERLY ALLOWING FOR PERIODIC
NOCTURNAL WIND SURGES EMANATING OFF OF SOUTH FLORIDA. THE
CONTINUING PREVAILING NORTHERLIES WILL RESULT IN VERY SLOW
MODERATION. EXPECT HIGHS TO REMAIN IN THE 60S AND LOWS IN THE 50S
THROUGH MUCH OF THE WEEK.
UNCERTAINTY BEGINS TO RAMP UP AFTER MID WEEK AS GUIDANCE INDICATES
THE PREVIOUSLY MENTIONED SHORTWAVE WILL CONTRIBUTE TO AN
AMPLIFYING SURFACE TROUGH ALONG THE OLD FRONTAL BOUNDARY SPLAYED
THE BAHAMAS. THE SPECIFICS REGARDING THIS TROUGHS DEVELOPMENT
WILL BE A DETERMINING FACTOR FOR ESSENTIALLY ALL FORECAST
VARIABLES IN THE KEYS. WHILE THE TROUGH IS NOT EXPECTED TO BE
STRONG, IT MAY BE ENOUGH TO HOLD WINDS STRONGER AND BACKED
NORTHERLY ACROSS THE KEYS. THE DEGREE OF TEMPERATURE AND MOISTURE
MODERATION WILL BE DEPENDENT ON HOW INCOMING STREAMLINES EVOLVE.
IT IS POSSIBLE THAT HIGHS AND LOWS WILL PUSH UP ABOVE 70 AND 60,
RESPECTIVELY, GIVEN A MORE MARITIME FLOW. RAIN POTENTIAL AND CLOUD
COVER WILL ALSO TICK UPWARDS THROUGH THIS PERIOD DUE TO
INCREASING LOWER LEVEL LIFT. INTERESTINGLY, CONSIDERABLE WARM AND
DRY MID LEVELS, ALONG WITH RELATIVELY LACKING SURFACE DEW POINTS,
APPEAR TO KEEP THUNDER CHANCES VERY LOW. THIS IS DESPITE THE JET
ENTRANCE REGION SWINGING ACROSS SOUTH FLORIDA AND THE KEYS LATE
WEDNESDAY.
ANOTHER SOUTHERN STREAM SHORTWAVE WILL SWING THROUGH A SHARPENING
MID LATITUDE TROUGH LATE IN THE WEEK. IN ADDITION TO SURFACE
TROUGHING DEVELOPING IN THE NORTHEAST GULF AND OFF THE CAROLINA
COAST, THE LINGERING SURFACE TROUGH IN THE STRAITS WILL RESPOND
WITH SOME GFS SOLUTIONS PINCHING OFF A SURFACE LOW. YET AGAIN, ALL
LOCAL FORECAST VARIABLES SUCH AS TEMPERATURE, DEW POINT, SKY
COVER, AND RAIN CHANCES WILL BE HIGHLY DEPENDENT ON THE ADDITIONAL
EVOLUTION OF THIS TROUGH/LOW. DESPITE THE HIGH AMOUNT OF
UNCERTAINTY REGARDING THIS SURFACE TROUGH, CONFIDENCE IS
INCREASING THAT AN ASSOCIATED POWERFUL COLD FRONT WILL RACE
SOUTHWARD ACROSS FLORIDA AND THE KEYS ON SATURDAY AS THE SURFACE
LOW'S/TROUGHS LIFT OUT WITH THE DEPARTING SHORTWAVE. THIS POWERFUL
REINFORCING COLD FRONT MAY DRIVE TEMPERATURES DOWN INTO THE 40S.
PORTIONS OF THE UPPER KEYS MAY SEE WIND CHILLS IN THE 30S DUE TO
THE CHILLY AIR POURING IN ON STRONG NORTHERLIES. STAY TUNED.
MARINE
ISSUED AT 1015 AM EST TUE JAN 27 2026
STRONG NORTHERLY BREEZES WILL RELAX THIS AFTERNOON AS HIGH
PRESSURE BUILDS ACROSS THE FLORIDA PENINSULA. SMALL CRAFT
ADVISORIES WILL BE PARED BACK FOR SEAS. OVER THE FOLLOWING COUPLE
OF DAYS, EXPECT PERIODIC WIND SURGES, FAVORING THE OVERNIGHT AND
EARLY MORNING HOURS DUE TO LAND BREEZE FORMATION AND A WEAK
REINFORCING COLD FRONT. FOR THE LATTER PORTION OF THE WORK WEEK, A
HIGH CELL WILL BUILD EASTWARD OFF THE SOUTHEASTERN UNITED STATES
AND INTO THE ATLANTIC. LOCAL BREEZES USUALLY RESPOND BY TRENDING
DOWN AND SLOWLY VEERING EAST NORTHEASTERLY. HOWEVER, GUIDANCE HAS
BEEN INCREASINGLY CONSISTENT WITH THE AMPLIFICATION OF AN INVERTED
TROUGH ACROSS THE EASTERN FLORIDA STRAITS. SHOULD THIS OCCUR,
WINDS WILL BE BOTH STRONGER AND HELD BACK NORTHERLY THAN NORMAL.
AVIATION
(15Z TAFS)
ISSUED AT 1015 AM EST TUE JAN 27 2026
VFR CONDITIONS WILL PREVAIL AT BOTH EYW AND MTH. CIGS DISSIPATED
EARLY THIS MORNING, AND THUS CLOUD CEILINGS ARE ABSENT FROM THE
TAFS. WINDS WILL REMAIN NORTH TO NORTHEASTERLY. BREEZES WILL
SLACKEN WITH GUSTS GRADUALLY DROPPING OUT OF THE TAFS. CROSSWINDS
WILL BE THE PRIMARY CONCERN AS FREQUENT GUSTS WILL CONTINUE
THROUGH SUNSET.
CLIMATE
ON THIS DAY IN 1905, THE DAILY RECORD LOW TEMPERATURE OF 44F WAS
RECORDED IN KEY WEST. TEMPERATURE RECORDS FOR KEY WEST DATE BACK TO
1873
PRELIMINARY POINT TEMPS/POPS
KEY WEST 68 59 67 56 / 0 0 10 0
MARATHON 68 58 67 55 / 0 0 10 10
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR GMZ031>035-
042>044-052>055-072>075.
PUBLIC/MARINE/FIRE...AJP
AVIATION/NOWCASTS....AJP
DATA ACQUISITION.....AJP
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