FXUS63 KPAH 142054
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
245 PM CST MON DEC 14 2009

.DISCUSSION...
COLD FRONT THIS AFTERNOON SITUATED JUST WEST OF THE FORECAST AREA 
WILL SWEEP THROUGH MOST OF THE REGION EARLY THIS EVENING. AS 
ANTICIPATED...NOT MUCH GOING ON PRECIP WISE ALONG THE FRONT. WILL 
LIKELY EITHER COME THROUGH DRY OR WITH SOME PATCHY VERY LIGHT RAIN 
OR DRIZZLE. MUCH COLDER AIR UP OVER THE PLAINS WILL DIVE SOUTH INTO 
THE REGION TUE/WED TIME FRAME. 

ALTHOUGH MODELS ARE KEEPING THE FRIGID COLD TO OUR NORTH WHERE THE 
SNOWPACK IS...WE WILL STILL BE MUCH COLDER FOR THE MID WEEK TIME 
FRAME. LOOKING UP STREAM....TEMPS ARE CURRENTLY STILL BELOW ZERO 
OVER THE NRN PLAINS. WILL SIDE WITH THE COLDER MET MOS NUMBERS...AND 
WILL PROBABLY UNDERCUT THESE NUMBERS A BIT AS WELL. MOS NUMBERS HAVE 
EXHIBITED A WARM BIAS WITH RECENT SHALLOW COLD AIR SHOTS...AND 
EXPECT THIS SITUATION TO BE NO DIFFERENT...ESPECIALLY WITH THE 
SURFACE HIGH COMING DOWN DIRECTLY OVER THE REGION WED. DIFFICULT TO 
SAY WHETHER TUE NIGHT OR WED NIGHT WILL BE THE COLDEST NIGHT. BEST 
COLD AIR ADVECTION WILL BE TUE NIGHT...BUT BEST RADIATIONAL NIGHT 
MAY BE WED NIGHT. COULD SEE TEENS BOTH NIGHTS.  

YET ANOTHER COLD FRONT WILL BRING ANOTHER SURGE OF COLD AIR LATE
IN THE WEEK AND ESPECIALLY INTO THE WEEKEND. BEHIND THIS SFC 
FRONT...THE LATEST ECMWF CONTINUES TO SHOW SOME LIGHT POST FRONTAL 
SNOWS...ESP SAT...AS A DISTURBANCE IN THE NORTHWEST FLOW MOVES 
THROUGH. HOWEVER...THE 00Z ECMWF IS MUCH MORE PRONOUNCED WITH THIS 
MID LEVEL FEATURE THAN ALL OTHER MODELS...AND MOST MODELS KEEP IT 
COMPLETELY DRY SAT. OUT OF RESPECT FOR THE ECMWF AND GIVEN THE FACT 
WE ALREADY HAVE SMALL CHCS FOR LIGHT SNOW CURRENTLY IN THE 
FORECAST...WILL NOT YANK THEM QUITE YET. EITHER WAY...NOT EXPECTING 
A MAJOR IMPACT...AT LEAST NOT FROM SNOW. 

CONFIDENCE IS GROWING THAT WE WILL SEE A SIGNIFICANT NEGATIVE HEIGHT 
ANOMALY DEVELOP ALOFT THIS WEEKEND...AS EXTREME BLOCKING PATTERN 
/POSITIVE HIGH ANOMALY/ OVER GREENLAND FORCES A MID LVL POLAR VORTEX 
TO RETROGRADE WEST AND SOUTH INTO THE SOUTHERN GREAT LAKES. THIS MAY 
END UP BRINGING THE COLDEST AIR OF THE SEASON STRAIGHT SOUTH OUT OF 
CENTRAL CANADA LATE BY SUN/MON TIME FRAME. WILL ALSO GO WELL BELOW 
MEX MOS TEMPS IN THIS TIME FRAME...WHICH HAVE TOO MUCH CLIMATOLOGY 
WEIGHTED IN THAT FAR OUT. 

&&

.AVIATION...
THE TENDENCY OF LOW CLOUDS TO BREAK UP WAS ALREADY REVERSING THIS 
AFTERNOON. EXPECT MVFR CIGS TO BECOME EVEN MORE WIDESPREAD THROUGH 
EARLY EVENING AS A COLD FRONT APPROACHES FROM THE NORTHWEST. WINDS 
WILL SHIFT INTO THE NORTHWEST AS THE FRONT PASSES IN THE 00Z TO 03Z 
TIME FRAME. WINDS WILL BE RATHER GUSTY IMMEDIATELY BEHIND THE FRONT. 
WIDESPREAD MVFR CIGS WILL PERSIST THROUGH THE NIGHT...THEN CLEARING 
IS LIKELY EARLY TUESDAY. 
  
&&

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

$$

DISCUSSION...MEFFERT
AVIATION...MY