583
FXUS62 KTAE 240801
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
300 AM EDT TUE NOV 24 2009
SYNOPSIS
08Z WATER VAPOR AND H4 RUC ANALYSIS SHOWING AN AMPLIFYING UPPER
LEVEL PATTERN ACROSS THE CENTRAL PORTION OF THE CONUS THIS MORNING
AS SHARP TROUGHING CONTINUES TO EXIT EAST FROM THE INTER-MOUNTAIN
WEST. THIS TROUGHING IS BORDERED BY WEAK RIDGING ALOFT ALONG BOTH
THE ATLANTIC AND PACIFIC COASTS. FLOW AHEAD OF THIS TROUGH IS
BEGINNING TO PULL ABUNDANT MID/UPPER LEVEL SOUTHERN STREAM MOISTURE
NORTH OVER THE FORECAST AREA. WEAK IMPULSE RIDING ALONG WITH THE
SOUTHERN STREAM OVER THE WESTERN/CENTRAL GULF IS BEGINNING TO FIRE
CONVECTION.
AT THE SURFACE...HIGH PRESSURE CONTINUES TO RIDGE DOWN INTO THE
REGION FROM THE NORTH. AREAS/WIDESPREAD LOW CLOUDS ARE AGAIN THE
RULE ACROSS THE AREA EARLY THIS MORNING WITH MOST STATIONS REPORTING
CEILINGS BETWEEN 1000 AND 2000KFT.
SHORT TERM (TODAY THROUGH THURSDAY)
TODAY...UPPER LEVEL TROUGH ACROSS THE CENTRAL PORTION OF THE NATION
WILL CONTINUE EAST TO THE MIDDLE MS VALLEY WHILE WEAK SOUTHERN
STREAM DISTURBANCE MOVES NE ACROSS THE CENTRAL GULF. SURFACE TROUGH
WILL BE EVOLVING BENEATH THIS GULF ENERGY...BUT OUR FORECAST AREA
WILL REMAIN UNDER CONTROL OF HIGH PRESSURE THROUGH THE AFTERNOON
HOURS. NOT ANTICIPATING MUCH IN THE WAY OF SUN TODAY. EVEN AS LOWER
CLOUDS THIS MORNING BURN OFF...ABUNDANT MID/HIGH LEVEL MOISTURE WILL
CONTINUE TO STREAM NORTH FROM THE GULF IN THE FORM OF CIRRUS.
TONIGHT AND WEDNESDAY...
INGREDIENTS APPEAR TO BE COMING TOGETHER FOR A PERIOD OF SHOWERS
ACROSS OUR EASTERN BIG BEND ZONES STARTING THIS EVENING AND LASTING
INTO WEDNESDAY MORNING. WELL DEFINED SURFACE TROUGH WILL MOVE INTO
THE EASTERN GULF OF MEXICO TONIGHT UNDERNEATH THE PARENT SOUTHERN
STREAM SHORTWAVE. GFS/ECMWF HAVE SLIGHTLY DIFFERENT EVOLUTIONS TO
THIS SURFACE FEATURE INTO TONIGHT (CLOSED LOW VS OPEN TROUGH).
HOWEVER...BOTH MODELS SHOWS SIMILAR DYNAMICS OVER SIMILAR LOCATIONS.
SHOULD BE NOTED...THAT ANY DEVIATION OF THESE DYNAMICS TO THE
EAST/SOUTH COULD KEEP THE MAJORITY OF THE RAINFALL OUT OF OUR ZONES.
AT LEAST FOR NOW...MODELS CONSENSUS DOES NOT SUPPORT THIS.
ZONE OF IMPRESSIVE ISENTROPIC UPGLIDE ALONG THE (295-305K)
SURFACES AHEAD AND NORTH OF THE LOW TRACK WILL CROSS THE
CENTRAL/NORTHERN FLORIDA PENINSULA TONIGHT INTO WEDNESDAY MORNING.
THE WESTERN PERIPHERY OF THIS BAND OF LIFT/MOISTURE IS EXPECTED TO
REACH OUR EASTERN BIG BEND ZONES. THIS LOWER LEVEL LIFT WILL BE
ENHANCED BY ANOTHER WELL DEFINED AREA OF DIVERGENCE (400-200MB)
PROGGED TO CROSS THE NORTH-CENTRAL PENINSULA...ASSOCIATED WITH THE
RRQ OF A DEPARTING JET STRUCTURE. CHANCES FOR SHOWERS OR PERIODS OF
RAIN FROM LATE THIS EVENING THROUGH WEDNESDAY MORNING LOOK TO
INCREASE AS ONE TRAVELS SOUTH AND EAST OF TALLAHASSEE AND VALDOSTA.
TO THE NORTH AND WEST OF THIS ZONE...RAIN CHANCES WILL DECREASE
RAPIDLY AWAY FROM THE BETTER DYNAMICS...AND WITHIN A MUCH DRIER
ATMOSPHERIC COLUMN. IN FACT...MOST OF OUR WESTERN AND NORTHERN ZONES
CAN EXPECT FAIR AND SEASONABLE WEATHER THROUGH THIS PERIOD. LOW
PRESSURE LOOKS TO TRANSLATE QUICKLY ACROSS THE FL PENINSULA AND OFF
THE SOUTHEAST COAST BY WEDNESDAY AFTERNOON WITH ANY SHWRS ENDING.
WEDNESDAY NIGHT AND THURSDAY...
IN THE WAKE OF WEDNESDAY'S LOW...GOOD AGREEMENT IN A MUCH DRIER AND
COOLER AIRMASS SURGING ACROSS THE FORECAST AREA AS THE MID/UPPER
LEVEL TROUGH AMPLIFIES INTO THE SOUTHEASTERN STATES. 850MB TEMPS ARE
PROGGED TO DROP THROUGH THE SINGLE DIGITS DURING THE DAYLIGHT HOURS
OF THURSDAY WITH THE 0C ISOTHERM APPROACHING THE NORTHWEST ZONES.
THE CONTINUOUS CAA THROUGH THE DAY WILL ALMOST CERTAINLY NOT ALLOW
TEMPS TO REACH THEIR FULL POTENTIAL AND WILL BE UNDERCUTTING THE MAV
NUMBERS BY AT LEAST A COUPLE OF DEGREES FOR DAYTIME HIGHS.
LONG TERM (FRIDAY THROUGH NEXT TUESDAY)
A HIGHLY AMPLIFIED MID/UPPER LEVEL PATTERN WILL BEGIN THE PERIOD
WITH A DEEP TROUGH DOWN THE EASTERN U.S. THE TROUGH MOVES EAST ON
FRIDAY WITH RIDGING BUILDING IN ACROSS THE LOCAL REGION OVER THE
WEEKEND. THEN THE GFS SHOWS A VERY SHARP TROUGH DEVELOPING THROUGH
THE NATION'S MIDSECTION MONDAY WITH THE NEXT STORM SYSTEM LIFTING
FROM THE LOWER MISSISSIPPI VALLEY NORTH NORTHEASTWARD TO THE OHIO
VALLEY DRAGGING A COLD INTO OUR CWA MONDAY NIGHT THROUGH TUESDAY.
THE 12Z EURO SOLUTION SHOWS THIS SYSTEM WEAKER AND SLOWER. FRIDAY
THROUGH SUNDAY WILL BE DRY WITH CHANCE POPS BEGINNING MONDAY AND
POSSIBLY CONTINUING THROUGH TUESDAY. UNTIL THEN...WE WILL SEE THE
COLDEST AIRMASS THIS FALL SEASON FILTER INTO THE AREA. A FEW OF THE
NORMALLY COLDER LOCATIONS MAY DROP TO THE FREEZING MARK SATURDAY
MORNING. OTHERWISE...LOWS IN THE MID TO UPPER 30S CAN BE EXPECTED
AWAY THE COASTAL AREAS EACH MORNING THROUGH THE WEEKEND. MIN TEMPS
WILL GRADUALLY MODERATE TO THE UPPER 40S TO LOWER 50S BY TUESDAY
MORNING. MAX TEMPS WILL ONLY REACH THE LOWER TO MID 60S FRIDAY AND
SATURDAY AND UPPER 60S BOTH SUNDAY AND MONDAY. MAX TEMPS ON TUESDAY
WILL ALL HINGE ON THE TIMING OF THE COLD FRONTAL PASSAGE.
.MARINE.
HIGH PRESSURE WILL CONTINUE TO RIDGE DOWN INTO THE NORTHEAST GULF
THROUGH THIS AFTERNOON. THE GRADIENT WILL BEGIN TO INCREASE THIS
EVENING AS TROUGHING...OR A WEAK AREA OF LOW PRESSURE...PASSES JUST
SOUTH OF THE WATERS. OFFSHORE WINDS AND SEAS MAY REACH CAUTIONARY
LEVELS FOR A TIME INTO WEDNESDAY MORNING BEFORE THE LOW PASSES EAST
OF THE REGION. MODERATE NORTH TO NORTHWEST FLOW WILL CONTINUE
THROUGH THE REMAINDER OF THE WORK WEEK...WITH ANOTHER PERIOD OF
CAUTIONARY...OR EVEN LOW END ADVISORY LEVEL WINDS LATER THURSDAY
THROUGH EARLY FRIDAY. WINDS AND SEAS SHOULD THEN DIMINISH FOR THE
UPCOMING WEEKEND AS HIGH PRESSURE AGAIN BUILDS OVER THE FORECAST
WATERS.
AVIATION
THE BLANKET OF STRATUS CONTINUES ACROSS THE REGION AND WILL KEEP
CIGS IN THE IFR RANGE OVERNIGHT. ALSO...WE EXPECT VSBYS TO LOWER TO
IFR LEVELS IN THE PRE-DAWN HOURS AT ALL BUT THE PFN TAF SITE.
CONDITIONS WILL GRADUALLY IMPROVE AFTER DAYBREAK TO VFR LEVELS.
HOWEVER...MVFR CIGS MAY LINGER INTO THE LATE MORNING/EARLY AFTERNOON
AT MOST SITES. WINDS WILL BE LIGHT FROM THE NORTHEAST.
FIRE WEATHER
NO CONCERNS IN THE SHORT TERM. CONDITIONS WILL NEED TO BE MONITORED
CLOSELY TOWARDS THE END OF THE WEEK INTO THE WEEKEND WHEN HIGH
PRESSURE BUILDS ACROSS THE SOUTHEAST U.S. SPREADING COOLER AND DRIER
AIR ACROSS THE TRI-STATE AREA.
PRELIMINARY POINT TEMPS/POPS
TALLAHASSEE 67 53 69 44 66 / 05 20 10 05 05
PANAMA CITY 69 53 69 48 65 / 05 10 10 05 05
DOTHAN 64 48 68 42 62 / 05 10 10 00 05
ALBANY 63 49 68 41 64 / 05 10 10 05 05
VALDOSTA 66 54 67 45 67 / 10 40 30 10 05
CROSS CITY 72 61 70 46 69 / 10 60 60 10 05
APALACHICOLA 68 57 70 47 66 / 10 20 20 05 05
TAE WATCHES/WARNINGS/ADVISORIES
AL...NONE.
GA...NONE.
FL...NONE.
GM...NONE.
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
LONG TERM/AVIATION/FIRE WX...BARRY
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