114  
FXUS62 KTBW 111131  
AFDTBW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL  
631 AM EST SUN DEC 11 2016  
   
AVIATION (12Z TAFS)
 
 
MAINLY VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD WITH  
LIGHT EAST TO NORTHEAST WINDS. BROKEN VFR CIGS WILL INVADE FROM  
THE EAST AS LOW LEVEL MOISTURE INCREASES. MVFR TO IFR CIGS MAY  
DEVELOP THIS EVENING AND OVERNIGHT AS WINDS BECOME MORE  
SOUTHEASTERLY.  
 
84/AUSTIN  
 

 
   
PREV DISCUSSION
 
/ISSUED 256 AM EST SUN DEC 11 2016/  
 
SHORT TERM (TODAY - MONDAY)...  
WV IMAGERY AND UPPER AIR PLOTS SHOWING FAST AND DRY WESTERLY  
UPPER FLOW OVER THE AREA THIS MORNING WITH ALL THE ACTIVE WEATHER  
WELL NW AND N OF THE LOCAL AREA. UPPER LONGWAVE ORIGINATING FROM  
CANADIAN TO REMAIN IN THE NORTHERN STREAM FLOW WITH ONLY SLIGHT  
EFFECT ON SOUTHERN TIER PATTERN THROUGH MONDAY. SURFACE HIGH  
PRESSURE MOVES OFF THE EASTERN SEABOARD TODAY AND INTO THE WESTERN  
ATLANTIC SINKING SOUTHWARD MONDAY WHILE COMPLEX WINTER STORM  
SYSTEM MOVES FROM THE ROCKIES THROUGH THE GREAT LAKES. EASTERLY  
LOW LEVEL WINDS TODAY VEER SOUTHEASTERLY MONDAY CONTINUING TO  
ADVECT ABUNDANT ATLANTIC MOISTURE INTO THE AREA WITH INCREASING  
TEMPS AND DEW POINTS WITH A FEW LIGHT SHOWERS OVER INTERIOR  
SECTIONS AREAS WHILE TEMPS CONTINUE TO CLIMB TO ABOVE NORMAL  
LEVELS. PATCHY FOG TO DEVELOP LATE TONIGHT INTO MONDAY MORNING  
WITH AREAS OF DENSE FOG POSSIBLE OVER INTERIOR LOCALS.  
 
MID/LONG TERM (MONDAY NIGHT - SATURDAY)...  
AN UPPER LOW OVER NORTHERN MANITOBA TRACKS AROUND HUDSON BAY AND  
INTO EASTERN CANADA BY LATE IN THE WORK WEEK WHILE A RIDGE RESIDES  
FROM THE GREATER ANTILLES TO SOUTHERN MEXICO...PROVIDING NEARLY  
ZONAL FLOW ACROSS MOST OF THE GULF REGION. FOR THE END OF THE  
WEEK AND GOING INTO THE WEEKEND A LONG WAVE TROUGH PUSHING ONSHORE  
THE WEST COAST FROM THE PACIFIC WILL HELP THE GREATER ANTILLES RIDGE  
BUILD NORTH FROM THE GULF THEN SLIDE ACROSS FL. AT THE SURFACE ATLANTIC  
HIGH PRESSURE RIDGES WEST ACROSS FL TO THE GULF UNTIL MIDWEEK WHEN IT  
SLIPS SOUTH IN RESPONSE TO A COLD FRONT MOVING INTO THE DEEP SOUTH.  
THIS FRONT CONTINUES MOVING SOUTH...CROSSING FL THU THEN EXITING FRI  
AS CANADIAN HIGH PRESSURE SETTLES INTO THE UPPER MID-WEST/OHIO VALLEY  
REGIONS. THE HIGH PRESSURE SHIFTS ACROSS THE EASTERN SEABOARD AND OUT  
OVER THE ATLANTIC BY SAT.  
 
THROUGH ABOUT MIDWEEK WEAK IMPULSES MOVING IN THE ZONAL FLOW ALOFT  
COULD SUPPORT A FEW SHOWERS BUT MOISTURE IS LIMITED...MODEL PWAT RUNS  
IN THE 0.9 TO 1.3 INCH RANGE...SO ANY COVERAGE STAYS IN THE SLIGHT CHANCE  
RANGE AND MAINLY IN THE NORTH. LOW LEVEL SOUTHEAST TO SOUTHWEST FLOW WILL  
KEEP TEMPERATURES ON THE WARM SIDE OF NORMAL. AS THE FRONT MOVES THROUGH  
THU LOW LEVEL FLOW TURNS TO WESTERLY THEN NORTHERLY...DRAGGING IN SOME  
DRIER AIR AND KEEPING THE FRONT RAIN FREE. AS THE HIGH PRESSURE SETTLES  
IN NORTH OF THE STATE THE FLOW BECOME NORTHEASTERLY FAIRLY QUICKLY...  
PRECLUDING ANY COOL DOWN. TEMPERATURES DO DROP BUT REMAIN ABOVE NORMAL.  
THE MAIN CONCERN WILL BE SOUTHERLY FLOW WITH ENOUGH MOISTURE AND GULF  
WATERS COOL ENOUGH TO SUPPORT SOME SEA FOG MON NIGHT INTO TUE NIGHT.  
 
AVIATION...  
GENERALLY VFR CONDITIONS EARLY THIS MORNING MAINLY SCT 3-5K FT  
CLOUD DECK MOVING ACROSS THE S FL PENINSULA. MAY SEE OCCASIONALLY  
BKN CIGS WITH THIS AREA OVER FMY AND RSW, AND POSSIBLY PGD.  
MODELS THEN BRING INCREASING LIKELIHOOD OF LOWER MVFR CIGS  
TOWARDS 00Z AREAWIDE.  
 
MARINE...  
WILL HOLD ONTO SCEC OVER OFFSHORE SOUTHERN WATERS EARLY THIS  
MORNING BASED ON LATEST BUOY OBS. HIGH PRESSURE MOVES OFF THE  
EASTERN SEABOARD TODAY AND INTO THE WESTERN ATLANTIC MONDAY. RIDGE  
AXIS SETTLES OVER THE FL PENINSULA AND E GULF WATERS THROUGH MID  
WEEK. GRADIENT WEAKENING TODAY AND WINDS AND SEAS FINALLY  
SUBSIDING TO BELOW HEADLINE CRITERIA AFTER 10 AM. WINDS VEER  
SOUTHERLY ADVECTING HIGHER DEWPOINTS AIRMASS OVER COOLER SHELF  
WATERS TO INCREASE THE POSSIBILITY OF MARINE FOG ESPECIALLY MID  
WEEK AHEAD OF SAGGING FRONTAL BOUNDARY. MODELS PUSH COLD FRONT  
OVER THE WATERS THURSDAY WITH QUICK NE WIND SHIFT.  
 
FIRE WEATHER...  
ABUNDANT LOW LEVEL MORE TO KEEP HUMIDITIES WELL ABOVE CRITICAL  
LEVELS TODAY THROUGH MID WEEK WHILE PATCHY FOG WILL BE POSSIBLE  
NIGHTLY.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
TPA 78 66 79 66 / 20 10 10 10  
FMY 81 66 83 67 / 20 20 20 10  
GIF 77 63 83 63 / 20 20 10 10  
SRQ 79 65 78 64 / 20 10 10 10  
BKV 77 60 80 58 / 20 10 10 10  
SPG 76 66 78 65 / 20 10 10 10  
 

 
   
TBW WATCHES/WARNINGS/ADVISORIES
 
 
FL...NONE.  
GULF WATERS...NONE.  

 
 

 
 
PRIOR AFD...  
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...25/DAVIS  
MID TERM/LONG TERM/DECISION SUPPORT...09/RUDE  
 
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