A discrete thunderstorm moved northeast over Grassy Key, accompanied by strong wind gusts.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS KEY wrote it up.
A discrete thunderstorm moved northeast over Grassy Key, accompanied by strong wind gusts.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Key West, FL wrote its last area forecast discussion before the first event at Dec 18, 9:57 AM EST, 2 hours 23 minutes earlier.
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS NATIONAL WEATHER SERVICE KEY WEST FL 957 AM EST SAT DEC 18 2010 .UPDATE... PREVIOUS SHIFT TOOK COGNIZANCE OF HIGH WINDS IN OUR ATLANTIC WATERS. BASED ON CURRENTLY AVAILABLE DATA WE WILL CONTINUE THE CAUTIONARY STATEMENT IN OUR UPCOMING ROUTINE ISSUANCE OF THE COASTAL ZONES. RADAR PRESENTATION AT THIS TIME IS VERY JUICY OUT BY DRY TORTUGAS. WE EXPECT THESE LINE-ECHO WAVE-PATTERNS TO MOVE NORTHEAST AND MISS THE ISLANDS...BUT WILL IMPACT OUR OFFSHORE GULF ZONES. WE HAVE REFINED SOME WORDING ACCORDINGLY...AND MAY ISSUE AN UPDATE TO THE GRIDS AND TEXT AROUND 12 NOON. && .MARINE... SMALL CRAFT SHOULD EXERCISE CAUTION ON THE ATLANTIC SIDE TODAY. THOSE IN THE WATERS KEY WEST TO DRY TORTUGAS SHOULD KEEP A WEATHER EYE TO THE WEST AS A LINE OF SHOWERS IS MOVING IN FROM THAT DIRECTION. RAIN COVERAGE AND INTENSITY WILL BE GREATEST IN OUR GULF WATERS OFFSHORE MAINLAND MONROE -- LOCALLY TORRENTIAL -- NOT FUN FOR RECREATIONAL BOATING. && .AVIATION... SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE KEY WEST AND MARATHON TERMINALS THIS AFTERNOON. A BRIEF PERIOD OF MVFR/IFR CIGS AND VSBYS IS LIKELY. CHECK THE LATEST SIGMETS AND AIRMETS. && ................................................................ .PREV DISCUSSION... /ISSUED 425 AM EST SAT DEC 18 2010/ A SURFACE ANALYSIS EARLY THIS MORNING REVEALS AN ELONGATED AREA OF LOW PRESSURE OVER THE GULF OF MEXICO AND FLORIDA PENINSULA WITH SEVERAL SMALLER SCALE CIRCULATIONS. AN UPPER-LEVEL CYCLONIC FLOW HAS DEVELOPED OVER THE GULF BASIN...WITH SEVERAL EMBEDDED SHORT-WAVE TROUGHS OF VARYING SCALES ALOFT. THE MOST INTENSE TROUGH CURRENTLY IS LOCATED NEAR THE TEXAS COASTAL PLAIN. THIS TROUGH IS LIKELY TO MIGRATE EASTWARD...INDUCING SURFACE CYCLOGENESIS OVER THE ATLANTIC EAST OF THE FLORIDA PENINSULA TONIGHT. THEREAFTER...CONTINENTAL AIR TRAJECTORIES WILL MAINTAIN FAIR AND DRY CONDITIONS FOR SEVERAL DAYS...AND WINDS WILL RETAIN A NORTHERLY COMPONENT. SUSTAINED WEAK THERMAL ADVECTION AT LOW LEVELS AND INCREASING CYCLONIC VORTICITY ADVECTION HIGHER UP HAS SIGNIFICANTLY DESTABILIZED TROPOSPHERIC COLUMNS LOCALLY DURING THE LAST 36 HOURS AS EVIDENCED BY A REVIEW OF KEY WEST RAWINSONDE DATA TRENDS. RECENT OBJECTIVE MESO SCALE ANALYSIS FROM THE STORM PREDICTION CENTER REVEAL SIGNIFICANT INCREASES IN SURFACE-BASED CONVECTIVE AVAILABLE POTENTIAL ENERGY ALONG AND SOUTH OF THE KEYS. FINALLY...THUNDERSTORMS ARE PRESENT WITHIN A HUNDRED MILES WEST OF THE SERVICE AREA. SO...ISOLATED THUNDERSTORMS ARE FORECAST FOR THE MARINE ZONES ALONG AND SOUTH OF THE KEYS FOR TODAY...WITH THE BEST CHANCE IN THE EARLY AFTERNOON WHEN STRONGER BOUNDARY LAYER MOISTURE CONVERGENCE WILL OVERSPREAD THE AREA. TEMPERATURES LIKELY WILL REACH 76-78F IN MANY ISLAND COMMUNITIES THIS AFTERNOON WHEN WINDS ARE SOUTH. AS WINDS TURN AROUND TO WEST AND THEN NORTHWEST...THE AIR WILL COOL SOME. HOWEVER...SIGNIFICANT LOW-LEVEL COLD THERMAL ADVECTION WILL NOT COMMENCE UNTIL SUNDAY. A COOLER AND DRIER AIR MASS WILL RUSH IN SUNDAY AND SUNDAY NIGHT...AND BY EARLY MONDAY TEMPERATURES LIKELY WILL RANGE FROM MID 50S UPPER KEYS TO NEAR 60F AROUND KEY WEST. AS WINDS VEER TO DUE NORTH MONDAY...AIR TRAJECTORIES WILL BE DIRECTLY OFF THE COOLER THAN NORMAL WATERS OF FLORIDA BAY AND THE WEST FLORIDA SHELF. SUBSEQUENTLY...WE HAVE PREDICTED HIGHS ONLY IN THE MID 60S...SEVERAL DEGREES BELOW MACHINE MODEL OUTPUT. && ................................................................ .KEY WATCHES/WARNINGS/ADVISORIES... FL...NONE. GM...NONE. && PUBLIC/MARINE.........DFM AVIATION/NOWCASTS.....FUTTERMAN DATA COLLECTION.......FUENTES VISIT US ON THE WEB AT WWW.WEATHER.GOV/KEYWEST
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE KEY WEST FL 600 AM EST SAT DEC 18 2010 FLZ076>078-GMZ031>033-052>054-072>075-191100- MONROE UPPER KEYS-MONROE MIDDLE KEYS-MONROE LOWER KEYS- FLORIDA BAY-GULF SIDE OF THE LOWER KEYS OUT 20 NM- GULF WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE 20 TO 60 NM OUT- OCEAN REEF TO CRAIG KEY OUT 20 NM- CRAIG KEY TO THE WEST END OF THE 7 MILE BRIDGE OUT 20 NM- WEST END OF THE 7 MILE BRIDGE TO KEY WEST OUT 20 NM- OCEAN REEF TO CRAIG KEY 20 TO 60 NM OUT- CRAIG KEY TO THE WEST END OF THE 7 MILE BRIDGE 20 TO 60 NM OUT- WEST END OF THE 7 MILE BRIDGE TO KEY WEST 20 TO 60 NM OUT- KEY WEST TO 20 NM WEST OF DRY TORTUGAS OUT 60 NM- 600 AM EST SAT DEC 18 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE FLORIDA KEYS AND ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT ANALYSIS OF SURFACE AND SATELLITE DATA SUGGESTS THAT AREAS OF FOG MAY ALREADY EXIST OVER FLORIDA BAY THIS MORNING. IF FOG IS PRESENT... THEN REDUCED VISIBILITY COULD POSE A HAZARD TO BOATERS OVER FLORIDA BAY TODAY. A MOIST AND UNSTABLE ATMOSPHERE WILL SUPPORT A FEW THUNDERSTORMS LATER THIS MORNING AND THIS AFTERNOON...MAINLY OVER THE WARMER WATERS OF THE GULF STREAM. THE PRIMARY THUNDERSTORM HAZARD WILL BE LIGHTNING STRIKES. A SECONDARY HAZARD WILL BE LOCALLY GUSTY WINDS OF 35 TO 40 KNOTS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... MARINE WEATHER SPOTTERS OPERATING OVER FLORIDA BAY ARE ENCOURAGED TO PROVIDE ANY REPORTS THAT CONFIRM OR DENY THE PRESENCE OF FOG. PLEASE CALL 305-295-1316 EXTENSION 3. THANK YOU. KASPER
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE KEY WEST FL
1014 AM EST SAT DEC 18 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0921 AM MARINE TSTM WIND 8 ENE FORT JEFFERSON AT 24.69N 82.77W
12/18/2010 M48 MPH GMZ075 XX C-MAN STATION
A WIND GUST OF 42 KNOTS...OR 48 MPH...FROM THE SOUTH WAS
REPORTED AT THE PULASKI SHOAL LIGHT CMAN STATION IN
ASSOCIATION WITH A PASSING LINE OF SHOWERS AND
THUNDERSTORMS.
&&
TFSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE KEY WEST FL 1200 PM EST SAT DEC 18 2010 FLZ077-181800- MONROE MIDDLE KEYS- INCLUDING THE COMMUNITIES OF...MARATHON 1200 PM EST SAT DEC 18 2010 ...SHOWERS AND THUNDERSTORMS WITH GUSTY WINDS IMPACTING MIDDLE KEYS... AT 1155 AM EST...NATIONAL WEATHER SERVICE METEOROLOGISTS IN KEY WEST DETECTED A CLUSTER OF VERY HEAVY SHOWERS AND THUNDERSTORMS IMPACTING THE MIDDLE KEYS BETWEEN LONG KEY AND GRASSY KEY...AND THE WATERS INSIDE THE REEF BETWEEN EAST TURTLE SHOAL LIGHT AND SOMBRERO KEY LIGHT. THROUGH 100 PM EST...AS MOST OF THIS CLUSTER MOVES NORTHWARD ACROSS THE MIDDLE KEYS...LOCATIONS BETWEEN LONG KEY AND MARATHON WILL RECEIVE BRIEF HEAVY DOWNPOURS ACCOMPANIED BY VISIBILITY LESS THAN 1 MILE...ISOLATED WIND GUSTS BETWEEN 30 AND 40 MPH...AND OCCASIONAL YET DANGEROUS CLOUD TO GROUND LIGHTNING STRIKES. TELEPHONE LINES AND METAL PIPES CONDUCT ELECTRICITY. YOU CAN BE INJURED OR KILLED IF LIGHTNING STRIKES NEARBY. UNPLUG APPLIANCES NOT NECESSARY FOR OBTAINING WEATHER INFORMATION. DO NOT TAKE A BATH OR SHOWER. GET OUT OF INDOOR POOLS. AVOID USING THE TELEPHONE OR ANY ELECTRICAL APPLIANCE DURING A THUNDERSTORM UNLESS IN AN EMERGENCY. FUTTERMAN
The Key West radar (KBYX), 77 km away, was scanning. The volume nearest the first event began at 17:19 UTC.
1 thunderstorm wind. Local standard time, as filed.
Power line down and resultant outage to 61 customers along the bayside of Grassy Key.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2010Every state in 2010This day in weather historyWarnings in Florida, December 2010
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 274066.