680  
FXUS62 KKEY 111847  
AFDKEY  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE KEY WEST FL  
247 PM EDT THU SEP 11 2025  
   
..NEW AVIATION
 
 
   
AVIATION
 
 
(18Z TAFS)  
ISSUED AT 247 PM EDT THU SEP 11 2025  
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT EYW AND MTH FOR THE REST  
OF TODAY AND INTO TONIGHT. WHILE CONDITIONS HAVE BEEN DRIER THAN  
EXPECTED, PRECIPITATION ON MAINLAND AND IN THE DEEP GULF IS  
TRUDGING SOUTH TOWARDS OUR WATERS. HAVE REMOVED VCSH FOR THE TIME  
BEING, BUT SHORT TERM AMENDMENTS WILL BE USED AS SHORT TERM  
IMPACTS BECOME APPARENT. NEAR SURFACE WINDS WILL BE LIGHT AND  
VARIABLE, BECOMING WEST TO NORTHWEST.  
 

 
   
PREVIOUS DISCUSSION
 
 
ISSUED AT 1135 AM EDT THU SEP 11 2025  
SKIES OVER THE FLORIDA KEYS ARE CLEARER THAN THEY WERE YESTERDAY  
AROUND THIS TIME. GOES-19 VISIBLE IMAGERY NOTES MAINLY FAIR  
WEATHER CUMULUS DOTTED AROUND OUR AREA OUTLINING RESIDUAL OUTFLOW  
BOUNDARIES FROM NOW DIMINISHED NOCTURNAL CONVECTION. A GLANCE AT  
KBYX RADAR CONFIRMS THAT ONLY A COUPLE SMALL SHOWERS BETWEEN THE  
DEEP GULF AND STRAITS OF FLORIDA REMAIN AFTER WIDELY SCATTERED  
SHOWERS AND SOME EMBEDDED THUNDERSTORMS POPPED UP EARLIER THIS  
MORNING. THE PREVIOUSLY MENTIONED OUTFLOW BOUNDARIES GENERALLY  
HAVE FREE REIGN TO MOVE AS THEY PLEASE SINCE LIGHT WESTERLY  
BREEZES, THAT ARE OCCASIONALLY VARIABLE, ARE CLOCKING IN ALONG  
OUR REEF OBSERVATION STATIONS. SURFACE TEMPERATURES ON LAND ARE  
UNSURPRISINGLY ALREADY IN THE UPPER 80S WITH DEWPOINTS PERSISTING  
IN THE UPPER 70S.  
 
THE SHORT TERM FORECAST IS A TOUCH CLOSER TO A NORMAL WET SEASON  
DAY THAN THE LAST FEW. LIGHT AND ALMOST VARIABLE WINDS COMBINED  
WITH ANOTHER PW OVER THE 90TH PERCENTILE MEASURED IN THIS  
MORNING'S KKEY SOUNDING WILL KEEP POSSIBLE CLOUD LINE FORMATION ON  
THE TABLE FOR THIS AFTERNOON. MEANWHILE, SHOWERS AND THUNDERSTORMS  
ARE EXPECTED TO DEVELOP ALONG THE FRONT STILL PARKED ACROSS  
MAINALND SOUTH FLORIDA THIS AFTERNOON. AS A SURFACE TROUGH IN THE  
GULF EDGES SOUTH, NORTHWESTERLY BREEZES WILL REESTABLISH  
THEMSELVES ACROSS OUR WATERS PERHAPS CREATING AN EASIER PATH INTO  
OUR AREA FOR SOME OF MAINLAND'S CONVECTION OR OUTFLOW BOUNDARIES.  
RECENT CAM RUNS CANNOT SEEM TO AGREE ON WHETHER OR NOT SHOWERS  
WILL FORM AHEAD OF MAINLAND'S INFLUENCE, BUT GENERALLY AGREE THAT  
SOMETHING WILL BE CROSSING THE KEYS FROM THE NORTH LATER TODAY.  
THUS OPTED TO HOLD 50 POPS FOR TODAY AND CONTINUING WITH A 40%  
INTO TONIGHT. RAIN CHANCES PEAK FOR THE FORECAST PERIOD STARTING  
TOMORROW AS THE FRONT FINALLY LOOKS TO SHIFT FURTHER SOUTH. HOW  
THAT IS GOING TO EFFECT THE REST OF THE FORECAST IS STILL IN FLUX  
OF COURSE, SO STAY TUNED.  
 

 
   
FORECAST
 
 
ISSUED AT 248 AM EDT THU SEP 11 2025  
UNCERTAINTY REMAINS QUITE HIGH THROUGH THE DURATION OF THE  
FORECAST. OVER THE NEXT COUPLE OF DAYS THE TROUGHING OVER THE  
EASTERN UNITED STATES WILL AMPLIFY, REACHING DOWN INTO THE YUCATAN  
BY THIS WEEKEND. THIS ALONG WITH PRECIPITABLE WATER REMAINING  
WELL ABOVE 2 INCHES WILL RESULT IN RAIN CHANCES REMAINING ABOVE  
NORMAL. THE HIGHEST RAIN CHANCES ARE EXPECTED IN THE FRIDAY  
THROUGH SATURDAY TIME FRAME AS THIS IS WHERE THE LOWER LEVEL  
TROUGHING AND CONFLUENT FLOW WILL BEST FOCUSED NEAR THE KEYS. IN  
ADDITION, THERE IS THE POTENTIAL FOR SOME UPPER LEVEL SUPPORT DUE  
TO THE UNUSUALLY AMPLIFIED UPPER TROUGH JUST TO OUR WEST. ALL  
GUIDANCE INDICATES A SURFACE HIGH OVER THE EASTERN UNITED STATES  
WILL SHOVE A FRONT SOUTHWARD THROUGH SOUTH FLORIDA TOMORROW AND  
FURTHER INTO THE STRAITS OR CUBA THIS WEEKEND. WITH THAT SAID, THE  
STRONGER WINDS ASSOCIATED WITH THE HIGH IS NOT EXPECTED TO MAKE  
MUCH HEADWAY INTO THE KEYS. AS A RESULT, WINDS ARE EXPECTED TO  
REMAIN LIGHT WHILST SHIFTING FROM NORTHWEST TO NORTH TO NORTHEAST  
SOMETIME THIS WEEKEND.  
 
THE TAIL OF THE UPPER LEVEL TROUGH IS EXPECTED TO CUT OFF LATE  
THIS WEEKEND AND BALL UP OVER THE EASTERN UNITED STATES EARLY  
NEXT WEEK WITH ASSOCIATED TROUGHING REMAINING ACROSS THE GULF.  
THIS IS EXPECTED TO HELP DEEPEN A COASTAL TROUGH OFF THE ATLANTIC  
COAST AND KEEP WEAK LOWER TROUGHING AND A MOISTURE RICH  
ATMOSPHERE ACROSS SOUTH FLORIDA AND THE KEYS. RAIN CHANCES WILL  
PROBABLY REMAIN ABOVE NORMAL IN THIS ENVIRONMENT. WINDS WILL BE  
HIGHLY DEPENDENT ON THE EVOLUTION OF ANY ATLANTIC TROUGHING. WITH  
THAT SAID, WINDS SHOULD TRANSITION TO GENTLE TO MODERATE NORTHEAST  
TO EASTERLIES EARLY NEXT WEEK.  
 

 
   
MARINE
 
 
ISSUED AT 1135 AM EDT THU SEP 11 2025  
NO WATCHES, WARNINGS, OR ADVISORIES ARE CURRENTLY IN EFFECT FOR  
THE COASTAL WATERS OF THE FLORIDA KEYS. FROM SYNOPSIS, A WEAK  
SURFACE TROUGH DRAPED ACROSS SOUTH FLORIDA. THIS WILL KEEP A VERY  
MOIST AND UNSETTLED ENVIRONMENT ACROSS OUR AREA. A STALLED FRONT  
ACROSS FLORIDA IS EXPECTED TO SLIDE SOUTHWARD INTO THE STRAITS  
THIS WEEKEND. AS A RESULT, RAIN CHANCES WILL REMAIN ELEVATED WHILE  
WINDS FIRM UP SLIGHTLY AND CLOCK FROM NORTHWEST TO NORTHEAST.  
WITH THAT SAID, THERE IS CONSIDERABLE UNCERTAINTY AS STRONGER  
BREEZES WILL NOT BE FAR OFF TO THE NORTH AND LIGHT AND VARIABLE  
BREEZES ARE EXPECTED JUST TO OUR EAST.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
KEY WEST 80 90 78 89 / 40 60 70 60  
MARATHON 79 89 78 87 / 40 60 70 60  
 

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

 
 

 
 
PUBLIC/MARINE/FIRE...JAM  
AVIATION/NOWCASTS....JAM  
DATA ACQUISITION.....JAM  
 
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