FXUS62 KJAX 090925
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
425 AM EST WED DEC 9 2009
...ISOLATED STRONG THUNDERSTORMS POSSIBLE TODAY WITH BREEZY TO
LOCALLY WINDY CONDITIONS ALONG WITH NEAR RECORD HIGH TEMPERATURES...
.SHORT TERM...
TODAY...STORM SYSTEM WILL NEAR THE GREAT LAKES REGION WITH TRAILING
FRONTAL BOUNDARY ADVANCING INTO THE JACKSONVILLE COUNTY WARNING
AREA. STRONG LOW LEVEL JET HAS ALIGNED ACROSS THE AREA...WITH BREEZY
SOUTHERLY WINDS ALREADY REPORTED AT SEVERAL LOCALES. WITH SOME
DAYTIME HEATING...ANTICIPATE WIND GUSTS TO AROUND 30 MPH TO
ESTABLISH ACROSS THE EASTERN ZONES BY MID-MORNING. THUS...WILL
ISSUE LAKE WIND ADVISORY FOR THIS AREA. WARM SOUTHWEST FLOW TODAY WILL
PUSH TEMPERATURES INTO THE UPPER 70S AND LOWER 80S WHICH WILL BE
NEAR RECORD HIGH TEMPS FOR THE DATE.
RECORD HIGH/YEAR OF OCCURRENCE FOR TODAY...
JAX 84/2004...
GNV 87/1951...
AMG 81/1978...
SSI 83/1978
IN ADDITION TO WARM CONDITIONS...SOUTHWESTERLY WINDS WILL MAINTAIN MUGGY
CONDITIONS WITH DEW-POINTS CLIMBING INTO THE UPPER 60S AND LOWER
70S. THE COMBINATION OF WARM/MUGGY CONDITIONS WILL LIKELY PROMOTE
THUNDERSTORM DEVELOPMENT ALONG FRONTAL BOUNDARY. ALTHOUGH DYNAMICS
ALOFT WILL BE LIMITED...THE PRESENCE OF A LOW LEVEL JET WILL
CREATE FAVORABLE CONDITIONS FOR PULSE STRONG TO SEVERE THUNDERSTORMS...
WITH THE MAIN CONCERN OF DAMAGING WINDS.
TONIGHT...NUMERICAL MODELS CONTINUE TO INDICATE FRONTAL BOUNDARY
WILL STALL ACROSS NORTHEAST FLORIDA. THE INTERACTION OF THIS FEATURE
WITH STRONG ISENTROPIC LIFT ABOVE THE SURFACE AND ARRIVAL OF NEXT
IMPULSE FROM THE GULF OF MEXICO WILL RESULT IN SCATTERED TO
NUMEROUS SHOWERS...WITH THE HIGHEST RAIN CHANCES ACROSS NORTHEAST
FLORIDA. ADDITIONALLY..ISOLATED THUNDERSTORMS WILL BE POSSIBLE IN
VICINITY OF FRONTAL BOUNDARY. THERE WILL LIKELY BE A LARGE
TEMPERATURE GRADIENT ACROSS THE AREA...WITH FORECAST LOWS RANGING
FROM LOWER 40S ACROSS INTERIOR SOUTHEAST GEORGIA TO AROUND 60 FOR
OUR SOUTHERN-MOST LOCALES IN NORTHEAST FLORIDA.
THURSDAY...LITTLE CHANGE IN SYNOPTIC/MESOSCALE FEATURES ARE
FORECAST DURING THE MORNING...WITH DRYING CONDITIONS EXPECTED IN
THE AFTERNOON AS AFOREMENTIONED FRONT BEGINS TO PULL AWAY AND HIGH
PRESSURE BUILDS INTO THE SOUTHEAST UNITED STATES. NORTHERLY WINDS WILL
CONTINUE TO ADVECT COOLER CONDITIONS WITH AFTERNOON HIGHS LIKELY
HOLDING IN THE 50S FOR AREAS NORTH OF A GAINESVILLE TO ST.
AUGUSTINE LINE.
THURSDAY NIGHT...COLD HIGH PRESSURE IS FORECAST TO SETTLE INTO THE
MID-ATLANTIC REGION. LOCALLY...LIGHT NORTHERLY WINDS AND LIMITED
CLOUDS WILL ALLOW TEMPERATURES TO PLUMMET. TEMPERATURES ARE
FORECAST TO DIP INTO THE 30S ACROSS INLAND SOUTHEAST GEORGIA AS
WELL AS INLAND AREAS ALONG AND NORTH OF THE I-10 CORRIDOR ACROSS
NORTHEAST FLORIDA. ADDITIONALLY...A LIGHT FREEZE WILL BE POSSIBLE
FOR THE DOUGLAS...HAZLEHURST AND BAXLEY AREAS.
FRIDAY...SURFACE HIGH IS FORECAST TO HOLD OVER THE MID-ATLANTIC
STATES WITH NEXT WEATHER SYSTEM EVOLVING OVER THE NORTHWEST GULF
OF MEXICO. A STRONG IMPULSE OF ENERGY IN ZONAL FLOW ALOFT IS
FORECAST TO TRAVERSE THE AREA...WITH CLOUDS THICKENING ACROSS THE
AREA ALONG WITH POSSIBLE SHOWERS ACROSS NORTHEAST FLORIDA.
NORTHEASTERLY WINDS IN CONCERT WITH INCREASING CLOUDS WILL KEEP
TEMPERATURES ON THE COOL SIDE...ESPECIALLY ACROSS SOUTHEAST GEORGIA
WHERE TEMPERATURES WILL STRUGGLE INTO THE 50S.
FRIDAY NIGHT...ADDITIONAL IMPULSES ARE FORECAST TO TRAVERSE THE
REGION AND THESE FEATURES WILL LIKELY PULL OLD FRONTAL BOUNDARY
NORTHWARD INTO THE JACKSONVILLE COUNTY WARNING AREA. DEEP LAYER
ASCENT WILL ENHANCE PRECIPITATION...WITH POTENTIAL FOR LOCALLY HEAVY
RAINFALL AND EMBEDDED THUNDERSTORM ACTIVITY.
.LONG TERM...SATURDAY THROUGH TUESDAY...
SATURDAY AND SUNDAY...SEVERAL LOW PRESSURE AREAS WILL ADVANCE FROM
THE GULF COAST REGION ACROSS THE JACKSONVILLE COUNTY WARNING AREA.
THESE FEATURES WILL MAINTAIN HIGH RAIN CHANCES THROUGH SUNDAY
MORNING. LAST SURFACE LOW IS FORECAST TO DEPART BY SUNDAY MORNING
WITH TRAILING COLD FRONT PUSHING THROUGH SUNDAY AFTERNOON. RAIN
WILL GENERALLY END WITH FRONTAL PASSAGE.
MONDAY AND TUESDAY...PROGRESSIVE PATTERN WILL CONTINUE WITH NEXT
IMPULSE OF ENERGY PUSHING INTO SOUTHEASTERN U.S. AND PRODUCING ANOTHER
WARM FRONTAL RAIN EVENT ON MONDAY AND TRAILING COLD FRONTAL RAIN
EVENT ON TUESDAY. TIMING AND STRENGTH OF EVENT STILL UNCERTAIN...BUT
TRAILING COLD FRONT MAY BE STRONG ENOUGH TO PRODUCE ISOLATED
SEVERE WEATHER.
&&
.AVIATION...
THE ONGOING WEATHER PATTERN WILL CONTINUE TO MAKE FOR A
CHALLENGING FORECAST. MODEL GUIDANCE HAS ONCE AGAIN BEEN TOO
PESSIMISTIC WITH CONDITIONS OVERNIGHT. ALL TERMINALS ARE
AT VFR LEVELS EARLY THIS MORNING. THIS IS EXPECTED TO CHANGE AS WE
HEAD TOWARD SUNRISE. STRATUS CLOUDS JUST UPSTREAM SHOULD CONTINUE TO
TRANSLATE EAST...RESULTING IN MVFR CEILINGS AT THE LOCAL
TERMINALS.
THE BIG CONCERN THIS MORNING WILL BE THE LOW LEVEL WINDSHEAR. A
STRONG LOW LEVEL JET IS RESULTING IN WIND SPEEDS NEAR 45 KNOTS
AROUND 1500 FEET. STRONGER MIXING AFTER SUNRISE WILL LOOSEN THIS
GRADIENT AS HIGHER GUSTS MIX DOWN TO THE SURFACE. FREQUENT GUSTS
TO 25 KNOTS ARE EXPECTED TODAY. CEILINGS SHOULD LIFT BACK INTO
THE VFR CATEGORY BY NOON. NUMEROUS RAIN SHOWERS AND ISOLATED
THUNDERSTORMS ARE EXPECTED DURING THE AFTERNOON. THIS ACTIVITY
WILL BE CAPABLE OF MIXING DOWN EVEN STRONGER WIND GUSTS. RAIN
SHOWERS WILL LIKELY LINGER THROUGH THE EVENING HOURS WITH PERHAPS
WIDESPREAD IFR CONDITIONS IN ADVANCE OF A COLD FRONT.
&&
.MARINE...
SOUTHWEST FLOW HAS INCREASED WITH CURRENT WIND SPEEDS IN THE 20 TO
25 KNOT RANGE OVER THE OFFSHORE ZONES. THESE WINDS WILL CONTINUE
THROUGH THE DAY THEN DROP BELOW SCA CRITERIA BY THIS EVENING. SEAS
TODAY WILL TOP OUT AROUND 7 FEET WELL OFFSHORE WITH UP TO 5 FOOTERS
POSSIBLE OVER OUTER PORTIONS OF THE NEARSHORE ZONES. SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED OVER THE WATERS THIS AFTERNOON
AND THIS EVENING AHEAD OF AN APPROACHING COLD FRONT.
NORTHWEST WINDS WILL INCREASE BRIEFLY IN THE WAKE OF THE COLD
FRONT ON THURSDAY. THESE WINDS SHOULD REMAIN JUST BELOW SCA
CRITERIA BUT SCEC CONDITIONS CAN BE EXPECTED. THE NEXT SURGE OF
WINDS WILL COME FRIDAY NIGHT AHEAD OF A STRONG LOW PRESSURE
SYSTEM. SCA CONDITIONS ARE ANTICIPATED ACROSS ALL OFFSHORE ZONES
AND THESE CONDITIONS MAY CONTINUE THROUGH SATURDAY ACROSS THE
NORTHERN ZONES.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 75 45 52 32 / 50 30 40 10
SSI 78 51 56 40 / 30 50 70 10
JAX 81 52 55 39 / 60 70 70 20
SGJ 83 58 60 46 / 50 70 70 20
GNV 79 54 58 40 / 70 70 70 20
OCF 81 56 64 42 / 70 70 70 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 3 PM EST THIS
AFTERNOON FOR ALACHUA-BAKER-BRADFORD-CLAY-DUVAL-FLAGLER-
MARION-NASSAU-PUTNAM-ST JOHNS-UNION.
GA...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 3 PM EST THIS
AFTERNOON FOR BRANTLEY-CHARLTON-COASTAL CAMDEN-COASTAL
GLYNN-INLAND CAMDEN-INLAND GLYNN-WAYNE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ALTAMAHA
SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-
FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-
ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
&&
$$
ZAPPE/SHULER/
