FXUS62 KTAE 080841
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
341 AM EST TUE DEC 8 2009
.SHORT TERM (TODAY-THURSDAY)...
MODELS SHOW A STRONG SHORT WAVE TROUGH THAT IS CURRENTLY OVER THE
FOUR CORNERS REGION TRANSLATING EAST OVER THE PLAINS THROUGH THE
DAY TODAY...THEN NORTHEAST TOWARD THE GREAT LAKES TUESDAY NIGHT
INTO WEDNESDAY. THIS WILL KEEP THE SOUTHWEST UPPER FLOW IN PLACE
ACROSS THE SOUTHEASTERN SECTION OF THE COUNTRY. AT THE
SURFACE...LOW PRESSURE ASSOCIATED WITH THIS SHORT WAVE TROUGH OUT
WEST WILL TRACK EAST OVER THE SOUTHERN PLAINS TODAY...THEN QUICKLY
LIFT NORTHEAST TOWARD THE GREAT LAKES AND DEEPEN TONIGHT INTO
WEDNESDAY. THE WARM FRONT THAT IS CURRENTLY SETUP OVER THE GULF
COAST STATES WILL LIFT NORTH AND NORTHEAST ACROSS THE REGION
TODAY AND WILL LEAD TO INCREASING MOISTURE AND RAIN CHANCES
ACROSS OUR AREA. LOW TO MID 60 DEW POINTS ARE FORECAST TO SPREAD
NORTH ACROSS THE SOUTHERN HALF OF THE LOCAL AREA TODAY...THEN INTO
THE UPPER 60S LATER TONIGHT CLOSER TO THE COAST.
WITH PLENTY OF STABLE AIR IN PLACE ACROSS OUR AREA...EXPECT MOST OF
THE THUNDERSTORM ACTIVITY TO REMAIN TO THE WEST TODAY. THE BEST
CHANCE FOR STORMS ACROSS OUR AREA WILL COME LATER THIS EVENING AND
THROUGH THE OVERNIGHT HOURS TONIGHT AS THE INSTABILITY AND LIFT
INCREASE WITH THE APPROACHING COLD FRONT FROM THE WEST. ALTHOUGH THE
INSTABILITY ACROSS OUR AREA WILL BE RELATIVELY WEAK...PLENTY OF
LOW/DEEP LAYER WIND SHEAR WILL MAINTAIN THE THREAT FOR AN ISOLATED
STRONG TO SEVERE STORM OR TWO TONIGHT INTO WEDNESDAY. THE SPC HAS
PLACED THE WESTERN HALF OF THE AREA (SE ALABAMA/ERN PANHANDLE) IN
THE DAY 1 SLIGHT RISK AREA...WHICH DOESN'T EXPIRE UNTIL 12Z
WEDNESDAY. TOTAL RAINFALL ACCUMULATIONS ARE FORECAST TO REMAIN IN
THE QUARTER TO HALF INCH RANGE WITH SOME LOCALLY HIGHER AMOUNTS
POSSIBLE.
THE COLD FRONT WILL MOVE ACROSS OUR AREA FROM NW TO SE WEDNESDAY
EVENING INTO THURSDAY WITH A MUCH DRIER AND COOLER AIRMASS FOLLOWING
ITS PASSAGE. TEMPERATURES ARE ONLY EXPECTED TO REACH THE MID 50S
ACROSS MUCH OF THE LOCAL AREA THROUGH THE DAY THURSDAY.
.LONG TERM (THURSDAY NIGHT THROUGH MONDAY)...
THE MEDIUM RANGE GUIDANCE AGREES THAT THE RATHER AMPLIFIED H5/H2
TROUGH FROM NRN CANADA SEEN DURING THE MID WEEK PERIOD WILL MOVE
EWD AND TREND TOWARDS A BROADER/FLATTER PATTERN BY THE UPCOMING
WEEKEND...WITH LARGELY ZONAL FLOW ACROSS SRN HALF OF CONUS. AT
SAME TIME WE SEE EVIDENCE OF UPSTREAM RIDGING OVER WRN CONUS.
STILL...EL NINO PATTERN PERSISTS AND SRN STREAM REMAINS
SUFFICIENTLY ACTIVE THRU EXTENDED TO CONTINUE SENDING A SERIES OF
SRN STREAM SHORTWAVES DOWNSTREAM TO STIMULATE SURFACE WAVES/FRONTS
AND GENERATE PERIODS OF ABOVE NORMAL RAIN. NEXT MAJOR IMPULSE
EXPECTED TO TRACK ACROSS THE SERN U.S. LATE INTO SAT.
AT LOWER LEVELS...PERIOD BEGINS WITH STALLED FRONT ACROSS S/CNTRL
GULF AND HIGH PRESSURE BUILDING OVER SE CONUS WITH A RETURN TO LOW
LEVEL E FLOW YIELDING A MODESTLY DRIER AND COOLER AIRMASS. BUT...AS
HIGH MOVES E OF CWA OVERNIGHT THURS...AHEAD OF NEXT UPSTREAM LOW...
FLOW QUICKLY BECOMES ONSHORE BY EARLY FRI. THIS LOW DEVELOPS IN THE
LWR MS VALLEY TO MOVE RAPIDLY ACROSS THE SOUTHEAST U.S. FRIDAY NIGHT
REACHING THE SRN MID-ATLC COAST LATER ON SAT. ANOTHER MESO LOW
DEVELOPS ALONG STALLED GULF FRONT AND RIDES NEWD HELPING LIFT FRONT
BACK NWD BY FRI FOR INCREASING CLOUDS AND MAINLY LIGHT RAIN
BEGINNING LATE THURS NIGHT (ESPECIALLY SRN THIRD OF CWA). LOW
REACHES GA COAST SAT MORN B4 LIFTING OFF TO CAROLINAS BY LATE SAT.
THIS MOVEMENT AIDED BY PASSING SHORTWAVE...DRAGS PARENT COLD FRONT
SEWD ACROSS REGION ON SAT WITH BY GOOD CHANCE OF SHWRS/ISOLD TSTMS
OVERSPREADING CWA. THIS FRONT WILL MOVE RAPIDLY SEWD TO N/CNTRL FL
BY SAT EVE AND SRN FL ON SUNDAY. IN WAKE OF EXITING IMPULSE/FRONT
...EXPECT DRIER AND COOLER AIR ADVECTING SEWD INTO THE LOCAL AREA
LATE SAT NIGHT THRU SUN NIGHT. MODELS HINT AT YET ANOTHER GULF LOW
MOVING NEWD IMPACTING MAINLY MARINE AREA ON MONDAY.
IN WAKE OF INITIAL FRONT....NIL POPS INTO EARLY FRI MORN...THEN
AHEAD AND ALONG NEXT COLD FRONT...LO-MID SCT POPS FRI AFTN THEN A
GOOD CHANCE OF PRECIP FRI NIGHT INTO SAT LATE EVE DECREASING TO
AOB WDLY SCT THRU SUN. THEN...LO SCT POPS MAINLY ON MONDAY. AS FAR
AS TEMPS...IN WAKE OF INITIAL COLD FRONT...THURS NIGHT INTO FRI SHOW
MINS/MAX WELL BELOW CLIMO (CLIMO IS LOW 40S MIN AND MID 60S MAX
TEMPS). THEN AS SECOND FRONTAL SYSTEMS APPROACH LOCAL REGION...MINS
RISE TO SLIGHTLY ABOVE CLIMO FRI NIGHT AND 5-10 DEGREES ABOVE CLIMO
ON SAT NIGHT B4 DROPPING TO 3-7 DEGREES ABOVE CLIMO SUN NIGHT.
MAX TEMPS SAT-MON HOVER AROUND CLIMO.
&&
.MARINE...SOUTHEAST WINDS AND SEAS WILL SHIFT TOWARD THE SOUTH TODAY
AND STRENGTHEN...THEN SOUTHWEST LATE TONIGHT INTO WEDNESDAY AS A
COLD FRONT APPROACHES FROM THE WEST. ADVISORY LEVEL WINDS AND SEAS
WILL BE POSSIBLE TONIGHT AND WEDNESDAY. IN ADDITION TO THE
INCREASING WINDS AND SEAS...INCREASING RAIN CHANCES ARE EXPECTED
THROUGH WEDNESDAY. A COLD FRONT WILL MOVE EAST OVER THE MARINE AREA
WEDNESDAY NIGHT WITH GUSTY NORTHWEST WINDS FOLLOWING ITS PASSAGE
THROUGH THE DAY THURSDAY. ANOTHER LOW DEVELOPS COME FRIDAY AND
FRIDAY NIGHT OVER THE NORTHWEST GULF...THEN TRANSLATES EAST ALONG
THE GULF COAST. THIS WILL KEEP THE GRADIENT ACROSS THE WATERS FAIRLY
TIGHT INTO THE WEEKEND.
&&
.AVIATION...
CIGS AND VIS WILL CONTINUE TO LOWER THROUGH REST OF PREDAWN HOURS
AS FOG IS ANTICIPATED AT ALL TERMINALS. PFN...DHN...AND ABY EXPECTED
TO STAY AROUND ALT AIRPORT THRESHOLDS...WHILE TLH AND VLD DIP DOWN
TO LANDING MINIMUMS THROUGH THE EARLY MORNING HOURS. AFTER
SUNRISE...LOW CLOUDS SHOULD STICK AROUND THROUGH THE DAY AND
ALL TERMINALS ARE EXPECTED TO REMAIN SOCKED IN THROUGH AT LEAST THE
AFTERNOON HOURS. LIGHT WINDS AT THE SFC ARE EXPECTED TO VEER TO MORE
EASTERLY THROUGH THE OVERNIGHT HOURS...THEN VEER MORE TO THE SE BY
AFTERNOON THIS SHOULD BRING AN INCREASE IN MOISTURE TO THE REGION.
RAIN CHANCES INCREASE BEGINNING THIS AFTERNOON FROM WEST TO EAST.
DHN AND ABY HAVE THE HIGHEST CHANCE FOR SHOWERS IN THE EARLY
AFTERNOON WITH RAIN OVERSPREADING REST OF TERMINALS BY LATE
AFTERNOON. AFTER 00Z WED...VSBYS/CIGS WILL AGAIN LWR TO MVFR AS WARM
FRONT LIFTS NWD ONTO COAST WITH INCREASING CHANCES FOR TSTMS AND
WITH LCL IFR ESPECIALLY IN ANY STRONG STORMS OR HEAVY RAIN. .
&&
.FIRE WEATHER...HIGH LEVEL MOISTURE IN THE LOW LEVELS THROUGH
TUESDAY AND INTO WEDNESDAY BEFORE COLD FRONT EXPECTED TO PASS
THROUGH. NO RED FLAG CONDITIONS ARE ANTICIPATED AT LEAST THROUGH
WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 68 64 77 50 59 / 50 40 60 20 10
PANAMA CITY 68 65 73 51 59 / 60 50 60 10 10
DOTHAN 63 61 76 43 56 / 80 70 40 10 10
ALBANY 62 61 77 42 58 / 70 50 60 10 10
VALDOSTA 68 63 77 49 58 / 60 30 60 20 10
CROSS CITY 72 63 76 57 63 / 30 20 50 40 20
APALACHICOLA 68 65 73 53 61 / 40 30 60 20 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
GA...NONE.
FL...NONE.
GM...NONE.
&&
$$
FOURNIER/FOURNIER
