FXUS62 KJAX 230731
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
231 AM EST WED DEC 23 2009
...MODERATING TEMPERATURES WITH INCREASING RAIN CHANCES FROM
CHRISTMAS EVE INTO CHRISTMAS MORNING...
.SHORT TERM...TODAY THROUGH SATURDAY...
TODAY...COOL START WITH HIGH PRESSURE OVER THE REGION SLOWLY
DRIFTING OFF TO THE EAST. PATCHY TO AREAS OF FROST OVER INLAND AREAS
EARLY THIS MORNING WITH MIN TEMPS IN THE 30S. WIDESPREAD CIRRUS
SHIELD WEST OF THE REGION WILL SLOWLY PUSH EAST INTO THE FORECAST
AREA AS IT THINS OUT AND SHOULD MAKE FOR PARTLY CLOUDY SKIES.
INCREASING EASTERLY FLOW WILL PUSH MAX TEMPS WELL INTO THE 60S THIS
AFTERNOON.
TONIGHT...CIRRUS SHIELD WILL CONTINUE TO THICKEN OVERNIGHT WITH
SKIES BECOMING MOSTLY CLOUDY AND EXPECT MIN TEMPS TO BE ABOUT 10
DEGREES WARMER IN THE 40S INLAND AND 50S NEAR THE COAST. MODELS
DISAGREE ON POSSIBLE FOG FORMATION AND WILL LEAN AGAINST ANY
SIGNIFICANT FOG DUE TO INCREASING HIGH CLOUDS.
CHRISTMAS EVE...CONTINUED MOSTLY CLOUDY SKIES THAT WILL SLOWLY LOWER
AND THICKEN INTO THE AFTERNOON WITH A 20-30% CHANCE OF SHOWERS LATER
IN THE DAY. E/SE SURFACE WINDS WILL INCREASE TO BREEZY 15-20 MPH
WITH GUSTS UP TO 30 MPH ALONG THE COASTAL AREAS. WARMER SELY FLOW
WILL CONTINUE TO PUSH MAX TEMPS UPWARDS INTO THE UPPER 60S ACRS SERN
GA AND INTO THE LOWER/MID 70S ACRS NERN FL.
CHRISTMAS EVE NIGHT...PRE-FRONTAL SQUALL LINE AND SHOWER ACTIVITY
WILL PUSH INTO THE FORECAST AREA WITH EMBEDDED STRONG TO POSSIBLY
SEVERE TSTMS OVERNIGHT. RAIN CHANCES WILL INCREASE THROUGH THE NIGHT
INTO THE 80-90% RANGE ACRS SERN GA AND INTO THE 60-80% RANGE ACRS
NERN FL. RAINFALL AMOUNTS AND INTENSITY APPEAR TO BE HIGHER THAN IN
PREVIOUS MODEL RUNS WITH AROUND AN INCH POSSIBLE ACRS SERN GA AND
MORE ALONG THE LINES OF A QUARTER TO HALF AN INCH ACRS NERN FL. HAVE
HELD OFF ON MENTION OF HEAVY RAIN/SEVERE TSTMS IN ZFP/GRIDS FOR NOW
BUT WILL CONTINUE TO HIGHLIGHT IN THE HWO.
CHRISTMAS DAY...SQUALL LINE THAT PUSHES INTO FORECAST AREA OVERNIGHT
WILL BE WEAKENING BUT ONGOING CHRISTMAS MORNING WITH TRAILING
LINGERING FRONTAL SHOWER ACTIVITY TO PUSH THROUGH DURING THE
AFTERNOON HOURS. LINGERING STRONG TO SVR STORMS COULD STILL VERY
WELL BE POSSIBLE EARLY ON BUT SEVERE THREAT WILL DIMINISH RAPIDLY AS
DYNAMICS PULLS QUICKLY NORTHEAST. TIMING OF FRONTAL PASSAGE IS STILL
IN QUESTION AND WILL SLOW DOWN AS IT REACHES ATLC COAST DURING THE
AFTERNOON HOURS. THIS WILL STILL ALLOW MAX TEMPS TO REACH INTO THE
UPPER 60S TO LOWER TO MID 70S ONCE AGAIN.
FRI NIGHT...AS TRAILING COLD FRONT PUSHES OFF THE ATLC COAST A FEW
LINGERING SHOWERS WILL BE POSSIBLE IN THE EVENING BUT RAIN CHANCES
FALL TO 20 PERCENT OR LESS AFTER SUNSET. COOLER AIR FILTERS INTO THE
REGION WITH MIN TEMPS IN THE 40S.
SATURDAY...NEXT WAVE ALONG THE FRONT WILL MOVE ACRS THE FLORIDA
PENINSULA MAINLY SOUTH OF THE FORECAST AREA AND HAVE KEPT POPS AT
THE SILENT 10% OR LESS RANGE FOR NOW. MAX TEMPS MUCH COOLER IN THE
UPPER 50S TO LOWER 60S.
.LONG TERM...SUNDAY THROUGH TUESDAY...
COLD HIGH PRESSURE SYSTEM PUSHES INTO THE SERN U.S. AND SETTLES JUST
NORTHWEST OF THE FORECAST AREA. TEMPERATURES WILL REMAIN BELOW
NORMAL THROUGH THE PERIOD WITH INLD FREEZES POSSIBLE EACH NIGHT WITH
THE COLDEST NIGHT EXPECTED TO BE MONDAY NIGHT WITH WIDESPREAD UPPER
20S POSSIBLE OVER INLD AREAS. MAX TEMPS WILL BE HELD DOWN INTO THE
MID/UPPER 50S ACRS THE FORECAST AREA.
A FEW GFS ENSEMBLE MEMBERS ARE SHOWING THE POSSIBILITY OF SOME
OVERRUNNING MOISTURE OVER THE ESTABLISHED COLD AIR ON MONDAY AND
WILL NEED TO MONITOR FOR POSSIBLE SPRINKLES OR IF COLD AIR IS DEEPER
THAN FORECAST MAYBE SOME SLEET.
&&
.AVIATION...A FEW PATCHES OF FOG TIL 12Z...OTHERWISE VFR.
&&
.MARINE...NO HEADLINES THROUGH TONIGHT. SCA CONDITIONS LIKELY
BY LATE THURSDAY OR THURSDAY NIGHT AS GRADIENT TIGHTENS WITH
APPROACH OF FRONTAL SYSTEM.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 63 43 67 54 / 0 10 30 80
SSI 63 55 68 61 / 0 0 20 90
JAX 66 49 71 59 / 0 0 20 80
SGJ 67 56 72 62 / 0 0 20 70
GNV 69 47 74 58 / 0 0 20 70
OCF 70 49 75 60 / 0 0 20 60
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
HESS/PETERSON
