FXUS62 KJAX 251951
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
249 PM EST WED NOV 25 2009
...RAIN ENDING TONIGHT WITH DRIER CONDITIONS ON THE WAY FOR
THANKSGIVING...
.SHORT TERM...TONIGHT THROUGH SATURDAY...
REST OF THIS AFTERNOON...500MB SHORTWAVE STILL SLOWLY TRACKING EAST
ACRS THE FLORIDA PANHANDLE AND WILL PUSH INTO THE FORECAST AREA LATE
THIS AFTERNOON. NUMEROUS LIGHT TO MODERATE SHOWER ACTIVITY WILL
CONTINUE ACRS THE FORECAST AREA. EMBEDDED TSTM ACTIVITY WILL BE
LIMITED TO THE COASTAL WATERS.
TONIGHT...VERY SLOW TRANSLATION OF SHORTWAVE ACRS THE FORECAST AND
INTO THE ATLC WILL END PCPN SLOWLY FROM THE NORTHWEST TO SOUTHEAST.
NOT MUCH WRAPAROUND CLOUDINESS SHOULD ALLOW FOR PARTIAL CLEARING
ACRS SERN GA THIS EVENING WITH SOME PATCHY FOG DEVELOPING AFTER
SUNSET THERE WHILE BREAKS IN THE CLOUDS ACRS NERN FL LATER ON
TONIGHT WILL ALLOW FOR AREAS OF FOG TO FORM IN SOME LOCATIONS. JUST
ENOUGH NWLY FLOW EXPECTED TO KEEP FROM GETTING ANY DENSE FOG. MIN
TEMPS FALLING ABOUT 10-15 DEG FROM CURRENT READINGS AND SHOULD END
UP IN THE 40S TO LOWER 50S.
THANKSGIVING DAY...HIGH TO BUILD IN AS SECONDARY WEAK FRONT CROSSES
THE FORECAST AREA DURING THE AFTERNOON AND CLEARS OUT ANY LINGERING
MORNING CLOUDS/FOG WITH SUNNY SKIES BY SUNSET IN ALL AREAS. MAX
TEMPS A BIT TRICKY BUT ENOUGH INSOLATION AND MIXING AHEAD OF
SECONDARY FRONT/TROF SHOULD ALLOW FOR MAX TEMPS INTO THE 65 TO 70
DEG RANGE.
THU NIGHT...STRONG COLD AIR ADVECTION IN NWLY FLOW WILL USHER IN
COLDER AIR OVERNIGHT WITH MIN TEMPS BOTTOMING OUT IN THE 30S UNDER
CLEAR SKIES WITH THE USUAL INLAND COLDER LOCATIONS NEAR FREEZING.
ENOUGH WIND AND DRIER AIR FILTERING IN TO PREVENT MUCH IN THE WAY OF
FROST FORMATION.
FRIDAY...COLD AIR ADVECTION SLOWLY WEAKENS UNDER SUNNY SKIES BUT NOT
BEFORE HOLDING MAX TEMPS DOWN INTO THE UPPER 50S AND LOWER 60S.
NORTHWEST WINDS CLOSE TO BREEZY CONDS AROUND 15 MPH WITH GUSTS TO
20-25MPH AT TIMES.
FRIDAY NIGHT...HIGH WILL SETTLE JUST WEST OF THE FORECAST AREA WITH
IDEAL RADIATIONAL COOLING CONDS AND EXPECT MIN TEMPS IN THE LOWER TO
MID 30S ACRS INLAND AREAS AND CLOSER TO 40 ALONG THE COAST. NEAR
CALM WINDS WILL PROMOTE PATCHY TO AREAS OF FROST AROUND SUNRISE SAT
MORNING AND HAVE PLACED INTO GRIDS/ZFP. COLDER LOCATIONS MAY SEE MIN
TEMPS AROUND 30 WITH A LIGHT FREEZE POSSIBLE BUT WITH DEWPOINTS IN
THE 30S AND RECENT RAINFALL IT IS GOING TO BE TOUGH TO HAVE A
WIDESPREAD FREEZE EVENT.
SATURDAY...HIGH DIRECTLY OVERHEAD AND EXPECT LIGHT WINDS AND LITTLE
MIXING AND MAX TEMPS ONLY REBOUND INTO THE MID/UPPER 60S. MODELS
ALSO SUGGESTING A GOOD BIT OF HIGH LEVEL CIRRUS STREAMING ACRS THE
FORECAST AREA AS WELL.
.LONG TERM...SUNDAY THROUGH WEDNESDAY...
SUNDAY...ANOTHER COLD START EXPECTED WITH MIN TEMPS IN THE 30S
INLAND AND PATCHY FROST IN THE EARLY MORNING BUT A RETURN TO LIGHT
SOUTHWEST FLOW IN THE LOWER LEVELS WILL PUSH MAX TEMPS INTO THE LOW
TO MID 70S WITH LESS CIRRUS CLOUDS EXPECTED.
MONDAY...MODELS HAVE BACKED OFF WITH STRONG FRONT APPROACHING THE
REGION AND A WEAKER FRONT WILL SLIDE CLOSE TO THE REGION WITH A
SLIGHT CHANCE OF SHOWERS POSSIBLE LATER IN THE DAY IF AT ALL. HAVE
BACKED OFF POPS SLOWLY WITH THIS PACKAGE. SOUTHWEST FLOW WILL KEEP
MAX TEMPS INTO THE 70S.
TUESDAY/WEDNESDAY...12Z GFS ENSEMBLE RUN SUPPORTS FRONT SAGGING INTO
THE FLORIDA PENINSULA WITH ANOTHER EL-NINO LIKE LOW PRESSURE
DEVELOPING IN THE GOMEX AND TRACKING ACRS THE REGION ON WEDNESDAY.
LOW CONFIDENCE IN THIS TIME FRAME AND HAVE TRIED TO COMPROMISE ON
TEMP/POP FORECAST AND GO CLOSE TO CONSENSUS NUMBERS. HAVE GONE WITH
RAIN CHANCES AT 40% WITH ENSEMBLE RUNS SUPPORTING AT LEAST A TENTH
TO QUARTER OF AN INCH OF RAIN ACRS THE FORECAST AREA IN EACH 12 HOUR
PERIOD FROM MONDAY NIGHT THROUGH WEDNESDAY. HAVE KEPT MENTION OF
TSTMS BUT ACTIVITY EXPECTED TO BE LIMITED THROUGH THE PERIOD.
&&
.AVIATION...CIGS GRADUALLY INCREASING THIS AFTERNOON TO MVFR AND VFR
THIS AFTERNOON. THIS TREND SHOULD CONTINUE OVERNIGHT AS RAIN TAPERS
OFF. MOSTLY VFR EXPECTED TONIGHT WITH TEMPO IFR LATE TONIGHT MAINLY
08Z-12Z AS FOG FORMS DUE TO DECREASING CLOUDS...LIGHT WINDS...AND
WET GROUND. VFR WILL DOMINATE AGAIN AFTER 12Z THURSDAY AS DRIER AIR
MOVES IN.
&&
.MARINE...OFFSHORE BUOYS STILL SHOW NORTH WINDS 20-25 KNOTS SO WILL
EXTEND SCA FOR OFFSHORE ZONES THROUGH THIS EVENING(03Z). CONDITIONS
WILL IMPROVE AROUND MIDNIGHT AS SURFACE LOW MOVES OFF THE EAST
CENTRAL FLORIDA COAST. AFTER A LULL THURSDAY MORNING...WINDS WILL
INCREASE AGAIN THURSDAY AFTERNOON AS COLD AIR ADVECTION INCREASES
WITH TIGHTENING PRESSURE GRADIENT. SCA HEADLINE WILL BE NEEDED AGAIN
FOR AT LEAST OFFSHORE ZONES THURSDAY NIGHT THROUGH FRIDAY.
&&
.FIRE WEATHER...DRIER AIR WILL MOVE INTO THE REGION ON THURSDAY AS
HIGH PRESSURE BUILDS IN. MIN RH'S AND WIND SPEEDS WILL PRODUCE NEAR
RED FLAG CONDITIONS FRIDAY AFTERNOON BUT WILL NOT ISSUE WATCH AT
THIS TIME DUE TO VERY MARGINAL CONDITIONS. NEAR MARGINAL RH'S WILL
OCCUR AGAIN SATURDAY AFTERNOON WITH LIGHTER WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 42 67 35 62 / 0 0 0 0
SSI 50 67 42 59 / 20 0 0 0
JAX 47 69 39 63 / 20 0 0 0
SGJ 53 70 44 63 / 30 10 0 0
GNV 49 70 38 63 / 20 0 0 0
OCF 51 71 40 63 / 30 10 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ALTAMAHA
SOUND GA TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
&&
$$
HESS/ZIBURA/PRESNALL
