FXUS63 KPAH 042103
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
303 PM CST FRI DEC 4 2009

.DISCUSSION...
BIGGEST CHALLENGES CONTINUE TO BE TEMPERATURES IN THE SHORT TERM
AND THEN TRACK...TIMING..AND PRECIP TYPE ASSOCIATED WITH THE STORM
SYSTEM AFFECTING THE REGION TUESDAY...TUESDAY NIGHT...AND WEDNESDAY.

COLD CANADIAN HIGH PRESSURE YIELDING SOME OF THE COLDEST
TEMPERATURES OF THE SEASON THUS FAR WILL KEEP THE REGION DRY AND
COOL THROUGH SUNDAY.

SUNDAY NIGHT A SURFACE FRONT/TROF WITH WEAK UPPER SUPPORT IS STILL
EXPECTED TO CROSS THE REGION. WITH THIS SYSTEM A RAIN/SNOW MIX IS
POSSIBLE OVER ALL EXCEPT THE SOUTHEAST QUARTER OF OUR CWA WITH
RAIN ELSEWHERE.

THE BEST CHANCES FOR PRECIP WILL BEGIN ON TUESDAY AS A STORM
SYSTEM MOVES INTO THE REGION. MODELS IN GOOD AGREEMENT IN THAT
THEY KEEP THE COLDEST AIR/THICKNESSES WELL TO OUR NORTH AND WEST
TUESDAY THROUGH TUESDAY EVENING...SO KEPT PRECIP ALL LIQUID IN
THESE PERIODS. AFTER MIDNIGHT TUESDAY NIGHT IS WHERE THINGS BEGIN
TO GET REALLY INTERESTING. LATEST GFS AND ECMWF MODEL RUNS HAVE
FLIP FLOPPED. YESTERDAY THE ECMWF TOOK THE SURFACE TO OUR NORTH
AND WEST KEEPING US IN THE WARMER AIR (RELATIVELY SPEAKING) AND
THE GFS TOOK THE LOW OVER OUR CWA. TODAYS RUNS ARE EXACTLY THE
OPPOSITE.

REGARDLESS OF THE TRACK OF THE LOW...LATE TUESDAY NIGHT COLDER AIR
BEGINS POURING INTO THE REGION ON THE BACK SIDE OF THE
SYSTEM...THE KEY IS HOW COLD. THEREFORE...DUE TO MODEL
UNCERTAINITY...KINDA PLAYED THE MIDDLE OF THE ROAD WHICH YIELDS
SNOW OVER THE NORTHWEST HALF OF THE CWA AND A RAIN/SNOW MIX
ELSEWHERE LATE TUESDAY NIGHT...THEN A RAIN/SNOW MIX OVER THE
NORTHWEST HALF AND RAIN ELSEWHERE ON WEDNESDAY. THIS EVENT IS
STILL A LONG WAY OUT...SO HOPEFULLY FUTURE MODEL RUNS WILL COME
INTO BETTER AGREEMENT...HOWEVER THE MIDDLE OF THE ROAD SOLUTION IS OFTEN
HOW THINGS PLAY OUT ANYWAY.

HIGH PRESSURE IN THE WAKE OF THIS SYSTEM SHOULD KEEP THE REGION
DRY AND COOLER THROUGH THURSDAY NIGHT...AND MAYBE BEYOND. LATEST RUNS NOW
SHOWING ANOTHER SYSTEM PUSHING ACROSS THE REGION ON FRIDAY...BUT
GIVEN THE PROPENSITY FOR MODELS TO BE TOO FAST THAT FAR OUT AND
THE FACT THAT THE MAJORITY OF MY NEIGHBORS ARE HOLDING OFF AS
WELL...WILL KEEP IT DRY FOR NOW.

FOR TEMPERATURES...CONTINUED TO LEAN TOWARD THE COLDER SIDE OF
GUIDANCE MINUS A DEGREE OR TWO.

&&

.AVIATION...
VFR VSBY AND CIGS THROUGH THE VALID TIME OF TAFS AT ALL SITES. WILL 
BRING SOME LOW CLOUDS AND POSSIBLY A CEILING AT KEVV AND KOWB 
THROUGH THE AFTERNOON HOURS. OTHER CONCERN WILL BE MID DECK 
APPROACHING FROM THE SOUTHWEST. THIS DECK IS MOVING IN AT 45 KNOTS 
BUT SHOULD ENCOUNTER SOME DIFFICULTY OVERTAKING THE DRY 
AIR...ESPECIALLY AS THE HIGH TRIES TO SHUNT IT OFF TO THE EAST.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
MO...NONE.
IL...NONE.
IN...NONE.
&&

$$

KH/JAP