FXUS62 KTAE 251916
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
216 PM EST WED NOV 25 2009
...COLDER WEATHER TO ARRIVE FOR LATE IN THE WEEK...
.SYNOPSIS...LOOKING AT THE LONG WAVE PATTERN ACROSS N AMERICA THIS
AFTERNOON...WE SEE RIDGES OFF THE E COAST AND OVER WRN CANADA AND
THE PAC NW. IN BETWEEN A LARGE TROUGH DOMINATES THE CENTRAL PART OF
THE CONTINENT. THERE ARE TWO PRIMARY SHORT WAVES WITHIN THIS TROUGH.
ONE IS DIVING SEWD ACROSS THE CENTRAL PLAINS. THE OTHER IS LIFTING
NEWD ACROSS THE GREAT LAKES WITH A LOBE EXTENDING SWD INTO THE TN
VALLEY. SURFACE ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER THE
CENTRAL GULF OF MEXICO ALONG A STATIONARY FRONT THAT EXTENDS FROM
THE NRN FL PENINSULA SW TO THE YUCATAN PENINSULA. A COLD FRONT IS
PUSHING EWD ACROSS NRN GA...SRN AL AND THE FL PANHANDLE. THIS FRONT
IS PRECEDED BY SOME SC CLOUDS BUT IS RAIN-FREE. WE CONTINUE TO SEE
MULTILAYER CLOUDS ACROSS MUCH OF THE FL PENINSULA. IN OUR FORECAST
AREA...MOST OF THE LOW CLOUDS HAVE FINALLY LIFTED...BUT WE CONTINUE
TO SEE A FEW SPRINKLES FALLING OUT OF A MID LEVEL DECK ACROSS THE
SERN THIRD OF THE FORECAST AREA. A VORT CENTER IS PASSING OVERHEAD
THIS AFTERNOON AND HAS ENHANCED THE VERY LIGHT PRECIPITATION OVER
THE NE GULF. SOME OF THIS WILL BE MEASURABLE ONCE IT REACHES THE ERN
FL BIG BEND.
&&
.SHORT TERM...TONIGHT THROUGH FRI NIGHT.
THE STUBBORN OVERCAST AND LIGHT RAIN WILL FINALLY BE SHUNTED E OF
THE AREA BY THIS EVENING WITH CLEARING SKIES OVERNIGHT. THE LONG
WAVE TROUGH WILL CONTINUE TO AMPLIFY AS IT MOVES EWD OVER THE NEXT
COUPLE OF DAYS. IT SHOULD REACH ITS HIGHEST AMPLITUDE AS IT SWEEPS
OVERHEAD THU NIGHT BEFORE LIFTING OFF TO THE NE. SURFACE HIGH
PRESSURE OVER THE GREAT BASIN WILL DIVE SEWD TO TX OVERNIGHT AND
THEN BUILD GRADUALLY EWD TO A POSITION OVER THE WRN PART OF OUR
FORECAST AREA BY 12Z SAT. THIS PATTERN WILL RESULT IN DRY AND COOL
CONDITIONS ACROSS THE REGION. LOWS TONIGHT WILL BE NEAR NORMAL.
HIGHS ON THANKSGIVING DAY WILL RUN 3-5 DEGREES BELOW NORMAL DESPITE
FULL SUNSHINE. STRONG COLD ADVECTION THU NIGHT WILL BRING TEMPS ALL
THE WAY TO THE MID 30S BY DAYBREAK FRI. AT THIS TIME...IT APPEARS
THAT WINDS WILL STAY UP ENOUGH TO PRECLUDE A FROST THREAT. HIGHS ON
FRI WILL BE HELD IN THE LOWER 60S...REMINISCENT OF MID WINTER. BY
SAT MORNING... WE SHOULD SEE IDEAL RADIATIONAL COOLING CONDITIONS
WITH LOWS GETTING INTO THE MID 30S ONCE AGAIN. CALM WINDS WILL ALLOW
FOR THE FORMATION OF FROST ACROSS MANY INLAND AREAS. IT IS NOT OUT
OF THE QUESTION THAT A FEW OF THE NORMALLY COLDEST LOCATIONS COULD
TOUCH THE FREEZING MARK AROUND SUNRISE SAT.
.LONG TERM...SAT THROUGH WED.
SURFACE HIGH PRESSURE ASSOCIATED WITH A COOL AND DRY AIR MASS WILL
BE CENTERED OVERHEAD SATURDAY. THIS HIGH WILL MOVE EAST ON SUNDAY AS
A VIGOROUS STORM SYSTEM BEGINS TO ORGANIZE ACROSS THE SOUTHERN
PLAINS AND LOWER MISSISSIPPI VALLEY. BY MONDAY MORNING A DEEP TROUGH
IS FORECAST TO CUT THROUGH THE CENTER OF THE CONUS WITH A CLOSED LOW
OVER THE NORTHERN PLAINS. THE LOW WILL DEEPEN AND DROP ALL THE WAY
TO THE ARKLATEX REGION BY 12Z TUESDAY...SLIDE EAST THROUGH LA AND
THEN LIFT NE TO THE GREAT LAKES BY THE END OF THE FORECAST PERIOD.
THE GFS PLACES THE SURFACE LOW OVER CENTRAL MISSISSIPPI 12Z MONDAY
WITH THE ASSOCIATED COLD FRONT SOUTHWEST THROUGH LA. SHOWERS AD
THUNDERSTORMS AHEAD OF THIS SYSTEM WILL OVERSPREAD OUR AREA MONDAY
INTO TUESDAY AS THE LOW SLOWLY TRANSLATES INTO ALABAMA. THE LOW THEN
LIFTS NORTHWARD THROUGH THE OHIO VALLEY INTO THE GREAT LAKES
WEDNESDAY DRAGGING THE FRONT ACROSS THE TRI-STATE REGION. THE 12Z
EURO SOLUTION CONTINUES TO SHOW A MUCH WEAKER SYSTEM. IF THE GFS
VERIFIES...THIS COULD BRING HEAVY RAINS AND POTENTIALLY SEVERE
WEATHER TO OUR REGION DURING THE MONDAY/MONDAY NIGHT TIME FRAME.
WILL TREND POPS UP SLIGHTLY MONDAY AND TUESDAY BUT KEEP THEM IN THE
CHANCE CATEGORY. MINIMUM TEMPERATURES WILL BE BELOW SEASONAL LEVELS
THROUGH THE PERIOD. MAX TEMPS WILL GENERALLY RANGE FROM THE MID 60S
TO THE LOWER 70S.
&&
.MARINE...TONIGHT THROUGH MON.
WINDS CONTINUE BE SUSTAINED AT EXERCISE CAUTION CRITERIA THIS
AFTERNOON AND WE DECIDED TO GO AHEAD WITH THE HEADLINE IN A LATE
UPDATE. WE DO EXPECT THE GRADIENT TO LOOSEN AS THE DRY FRONT
APPROACHES OVERNIGHT. BEHIND THE FRONT...THE GRADIENT WILL TIGHTEN
ONCE AGAIN WITH EXERCISE CAUTION CONDITIONS FORECAST BY THU
AFTERNOON AND ADVISORY CONDITIONS EXPECTED FOR THU NIGHT INTO FRI
MORNING. CONDITIONS WILL THEN IMPROVE QUICKLY AS SURFACE HIGH
PRESSURE BUILDS OVER THE AREA FROM FRI THROUGH THE WEEKEND.
&&
.AVIATION...THROUGH 18Z THU.
CLOUDINESS ASSOCIATED WITH COLD FRONT EXTENDING FROM MIDDLE GA TO
THE FL BIG BEND COAST STILL AFFECTING VLD WITH MVFR CIGS. ANOTHER
BAND OF LOW STRATOCU EXTENDING FROM N GA TO SOUTH CENTRAL ALABAMA IS
PROGRESSING TOWARD DHN AND ABY TERMINALS THIS AFTERNOON AS REFLECTED
IN TAFS. NO OTHER AVIATION WX CONCERNS OVERNIGHT AND SATURDAY.
&&
.FIRE WEATHER...WE WILL BE ISSUING A FIRE WEATHER WATCH FOR ALL BUT
TWO OF OUR FL ZONES FOR THU AFTERNOON. DURATIONS OF RH ARE RIGHT AT
FOUR HOURS...SO DO NOT FEEL CONFIDENT ENOUGH TO GO WITH A WARNING AT
THIS TIME. FOR FRI...DURATIONS LOOK MORE CERTAIN AND A WATCH WILL BE
POSTED FOR THAT AFTERNOON AS WELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 45 66 35 63 34 / 00 00 00 00 00
PANAMA CITY 48 65 43 61 42 / 00 00 00 00 00
DOTHAN 42 63 35 60 35 / 00 00 00 00 00
ALBANY 42 64 35 62 34 / 00 00 00 00 00
VALDOSTA 44 66 36 61 35 / 05 00 00 00 00
CROSS CITY 48 69 36 63 34 / 10 00 00 00 00
APALACHICOLA 46 66 39 62 37 / 00 00 00 00 00
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
GA...NONE.
FL...FIRE WEATHER WATCH FROM 18-22Z THU FOR ALL ZONES EXCEPT
LAFAYETTE AND DIXIE.
FIRE WEATHER WATCH FROM 18-23Z FRI FOR ALL ZONES.
GM...NONE.
&&
$$
AVIATION...GOREE
LONG TERM DISCUSSION...BARRY
REST OF DISCUSSION...WOOL
