699  
FXUS62 KJAX 252346  
AFDJAX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE JACKSONVILLE FL  
746 PM EDT MON OCT 25 2021  
   
UPDATE
 
 
A COLD FRONT WILL MOVE SOUTHEAST ACROSS AREA OVERNIGHT. A FEW  
SHOWERS MAY DEVELOP ON THE FRONT ITSELF AS IT PASSES THROUGH.  
NOTICEABLY DRIER AIR WILL FOLLOW THE FRONT, WITH DEWPOINTS  
FALLING OVERNIGHT.  
 

 
   
AVIATION
 
 
[THROUGH 00Z WEDNESDAY]  
 
A FEW SHOWERS ARE POSSIBLE OVERNIGHT, WHICH COULD CAUSE A BRIEF  
RESTRICTION. OTHERWISE, PREVAILING VFR CONDITIONS EXPECTED THIS  
00Z TAF PERIOD.  
 

 
   
PREV DISCUSSION [314 PM EDT]
 
 
   
NEAR TERM [THROUGH TONIGHT]
 
 
SCATTERED SHOWERS (WITH A LONE THUNDERSTORM POSSIBLE MAINLY SOUTH  
OF I-10) WILL CONTINUE THROUGH EARLY THIS EVENING AHEAD OF AN  
APPROACHING COLD FRONT. MOST OF THE SHOWER ACTIVITY WILL FADE  
AFTER SUNSET, BUT THERE IS A LOW CHANCE (< 20 %) OF SPOTTY  
SHOWERS THROUGH THE NIGHT ALONG THE ACTUAL COLD FRONT ITSELF AS IT  
SETTLES SOUTHWARD ACROSS THE AREA THROUGH DAYBREAK TUESDAY. LOW  
STRATUS AND PATCHY, INTERMITTENT GROUND FOG WILL ADVECT INLAND  
FROM THE GOMEX UNDER WSW FLOW AHEAD OF THE FRONT SOUTH OF THE I-10  
CORRIDOR, EXPANDING EASTWARD ALONG AND SOUTH OF A GAINESVILLE TO  
ST. AUGUSTINE LINE THROUGH 12Z. CLOUDS WILL DECREASE IN COVERAGE  
ACROSS SE GA UNDER DRIER, COOLER POST-FRONTAL FLOW WHERE LOW  
TEMPERATURES WILL FALL INTO THE MID/UPPER 50S. LINGERING CLOUDS  
ACROSS NE FL WILL KEEP TEMPS MORE MILD WITH LOWS RANGING IN THE  
60S TO NEAR 70 ALONG THE EXITING FRONT.  
 
   
SHORT TERM [TUESDAY THROUGH WEDNESDAY NIGHT]
 
 
COOLER AND DRY UNDER DEEP LAYER NW FLOW TUESDAY AS SURFACE HIGH  
PRESSURE BUILDS NW OF THE REGION AND AN UPPER RIDGE BUILDS  
EASTWARD ACROSS THE GULF COAST STATES. MOSTLY SUNNY SKIES WILL  
PREVAIL UNDER BREEZY NW WINDS 10-15 MPH AND GUSTS 1-25 MPH AT  
TIMES. WINDS RELAX INTO TUE NIGHT AS THE SURFACE RIDGE SETTLES  
ACROSS THE SE ATLANTIC COAST INTO WEDNESDAY UNDER A WEAKENING  
UPPER RIDGE. MID AND HIGH CLOUDS INCREASE FROM THE WEST WEDNESDAY  
AS A POTENT FRONTAL SYSTEM DEVELOPS ACROSS THE LOWER MS RIVER  
VALLEY, WITH A CHANCE OF LATE NIGHT SHOWERS AND ISOLATED T'STORMS AFTER  
MIDNIGHT WED NIGHT THROUGH SUNRISE THU MORNING AS A WARM FRONT LIFTS  
UP THE FL PENINSULA AND ACROSS SE GA.  
 
HIGH TEMPERATURES WILL RANGE NEAR CLIMO TUESDAY FROM THE MID 70S  
ACROSS SE GA TO THE LOWER 80S ACROSS INLAND NE FL. DRIER AIR AND  
LIGHTER WINDS TUE NIGHT WILL ENABLE LOWS TO FALL BELOW CLIMO  
VALUES FROM NEAR 50 INLAND TO NEAR 60 TOWARD THE COAST UNDER LIGHT  
NORTHERLY DRAINAGE WINDS. HIGH TEMPERATURES WILL REMAIN MILD  
WEDNESDAY AND GENERALLY NEAR CLIMO VALUES IN THE MID/UPPER 70S TO  
LOW 80S. A WARMING TREND ENSUES WED NIGHT AS WARM AIR ADVECTION  
PATTERN DEVELOPS AHEAD OF APPROACHING FRONTAL SYSTEM, WITH LOW  
TEMPS LIKELY REACHED AROUND MIDNIGHT IN THE UPPER 50S TO LOW 60S,  
THEN WARMING THROUGH SUNRISE THU AS DEEP LAYER SOUTHERLY FLOW  
INCREASES.  
 
   
LONG TERM [THURSDAY THROUGH MONDAY]
 
 
THU...POTENTIAL STRONG TO SEVERE THUNDERSTORMS AS A PRE-FRONTAL  
SQUALL LINE MOVES ACROSS THE LOCAL AREA. OUTSIDE OF STORMS, NON-  
CONVECTIVE WIND GUSTS NEAR 35 MPH AT TIMES COULD ALSO CAUSE MINOR  
WIND DAMAGE. VERY STRONG DYNAMICAL FORCING WILL BE IN PLACE WITH  
HIGH MOISTURE CONTENT, BUT LOW LEVEL INSTABILITY WILL BE LIMITED  
GIVEN DRIER LOW LEVEL AIR IN PLACE FROM TONIGHT'S COLD FRONT  
PASSAGE AND ABUNDANT CLOUD COVER. LATEST SREF PROBABILITY GUIDANCE  
FOR CAPE INDICATED ONLY 10-30% OF MUCAPE OF 500 J/KG ACROSS THE  
FORECAST AREA, WITH THE 50% POTENTIAL SOUTH OF GAINESVILLE TO ST.  
AUGUSTINE. THE LACK OF INSTABILITY WILL LIMIT THE ABILITY FOR  
DEEPER CONVECTIVE GROWTH AND MIXING DOWN OF STRONGER WINDS, BUT  
GIVEN THE STRENGTH OF IMPRESSIVE DYNAMICS INCLUDING A  
STRENGTHENING 850 MB JET OF 45-50 KTS ACROSS NE FL WILL CONTINUE  
STRONG/SEVERE STORM POTENTIAL. THE MORE FAVORED AREAS FOR SEVERE  
STORMS WILL FOCUS ACROSS THE SUWANNEE RIVER VALLEY OF NE FL  
EXTENDING TOWARD THE ATLANTIC WHERE JUICIER NEAR 70 DEG DEW PTS  
WILL PIVOT NORTHWARD JUST AHEAD OF THE APPROACHING SURFACE FRONT  
THROUGH THE DAY THU, ROUGHLY FROM TRENTON TO GAINESVILLE TO ST.  
AUGUSTINE SOUTHWARD. THE GREATEST SEVERE STORM CONCERN WILL BE  
DAMAGING WIND GUSTS, WITH ISOLATED TORNADO POTENTIAL WHERE LOW  
LEVEL SSE WINDS WILL ELEVATE HELICITY.  
 
MODEL DISCREPANCIES CONTINUE WITH TIMING WITH THE ECMWF MORE  
PROGRESSIVE BRINGING THE BULK OF PRECIP/STORMS ACROSS THE AREA  
EARLY THU MORNING EXITING THE COAST EARLY THU AFTERNOON, WHILE  
BOTH THE GFS AND NAM SHOW SLOWER SOLUTIONS WITH PRECIP OVERSPREADING  
WEST-EAST THROUGH THE DAY THURSDAY, EXITING THE LOCAL COAST THU  
EVENING. STORM TOTAL PRECIPITATION WITH THIS SYSTEM IS EXPECTED TO  
RANGE FROM 0.5 INCHES TO 2 INCHES UP TOWARD THE ALTAMAHA RIVER  
BASIN, OVERALL A MUCH WELCOMED WIDESPREAD WETTING RAINFALL FOR THE  
LOCAL AREA.  
 
FRI & SAT...LINGERING CLOUDS, BREEZY WITH SCATTERED LIGHT  
SHOWER POTENTIAL FRIDAY THEN DRY SATURDAY AS WAVES OF UPPER LEVEL  
ENERGY ROTATE OVER THE AREA ON THE SOUTH SIDE OF THE CUT-OFF UPPER  
LEVEL LOW ACROSS THE MID-ATLANTIC REGION. OPTED TO LEAVE OUT T'STORM  
POTENTIAL FOR NOW GIVEN HIGH LOW LEVEL STABILITY BUT THERE COULD  
BE ELEVATED T'STORM POTENTIAL FRIDAY. MUCH COLDER TEMPERATURES  
WILL FUNNEL SOUTHWARD ACROSS THE AREA UNDER EXTENSIVE WRAP-AROUND  
LOW LEVEL CLOUDS AND COOL, BREEZY WNW WINDS. HIGH TEMPERATURES  
WILL GENERALLY RANGE IN THE MID/UPPER 60S TO LOW 70S WITH LOWS IN  
THE 40S WELL INLAND TO 50S COAST AND OUR SOUTHERN FL ZONES.  
 
SUN & MON...COLDER AND DRY WITH DECREASING CLOUD COVER SUNDAY  
BECOMING MOSTLY CLEAR INTO MONDAY AS SURFACE HIGH PRESSURE BUILDS  
WEST THEN NORTHWEST OF THE REGION AND UPPER LEVEL FLOW BECOMES  
ZONAL. BELOW NORMAL TEMPERATURES CONTINUE WITH SOME WARMING INTO  
MONDAY WITH HIGHS IN THE LOW/MID 70S AND LOWS IN THE MID 40S TO  
MID 50S INLAND TO NEAR 60 COAST.  
 
   
MARINE
 
 
A COLD FRONT WILL MOVE ACROSS THE LOCAL WATERS TONIGHT WITH AN  
INCREASE IN WNW WINDS AFTER MIDNIGHT THROUGH SUNRISE TUESDAY WITH  
WINDS INCREASING TO 15-20 KTS. ADVISORY SMALL CRAFT EXERCISE  
CAUTION CONDITIONS FOR ALL LOCAL WATERS. NW WINDS RELAX TUE  
AFTERNOON AS HIGH PRESSURE BUILDS TO THE NORTHWEST THEN ACROSS  
THE LOCAL WATERS THROUGH WEDNESDAY. A WARM FRONT WILL LIFT NORTH  
ACROSS THE WATERS LATE WEDNESDAY NIGHT. A COLD FRONT WILL APPROACH  
THURSDAY PRECEDED BY STRENGTHENING SOUTHERLY WINDS TO ADVISORY  
LEVELS AND THUNDERSTORMS. ADVISORY CONDITIONS ARE EXPECTED THROUGH  
FRIDAY, THEN WINDS DECREASE INTO THE WEEKEND AS HIGH PRESSURE  
BUILDS EAST ACROSS THE GULF COAST STATES.  
 
RIP CURRENTS: LOW RISK TODAY AND TUESDAY.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
AMG 59 74 48 73 56 / 20 0 0 0 40  
SSI 64 77 56 74 62 / 20 0 0 0 30  
JAX 66 79 55 77 62 / 20 0 0 0 30  
SGJ 68 82 58 78 65 / 20 0 0 0 30  
GNV 66 82 52 79 61 / 20 0 0 0 40  
OCF 69 84 54 80 61 / 20 0 0 0 40  
 

 
   
JAX WATCHES/WARNINGS/ADVISORIES
 
 
FL...NONE.  
GA...NONE.  
AM...NONE.  

 
 
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