000
FXUS63 KPAH 171916
AFDPAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
215 PM CDT SAT MAY 17 2008
.DISCUSSION...
SHORT TERM...THROUGH MON NIGHT
SHORT TERM FOCUS IS ON 500MB SHORT WAVE/WEAK SURFACE COLD FRONT
MOVING S ACROSS THE FA TONIGHT/EARLY SUN AND ON ANOTHER MON-TUE
TIME FRAME. TONIGHT`S RELATIVELY WEAK SYSTEM HAD SLOWED A FEW HOURS
AND WILL THEREFORE EXTEND A CHANCE OF SHOWERS INTO SUN MORNING
ACROSS THE FAR SOUTHEAST PART OF THE FA. HOWEVER REGARDLESS OF
CHANCES ANY RAINFALL IS EXPECTED TO REMAIN LIGHT. WHERE ANY RAIN
FALLS THRU SUN AM...AMOUNTS SHOULD ONLY BE A TRACE TO A FEW
HUNDRETHS OF AN INCH WITH THE BEST CHANCE FOR RAIN FROM SW INDIANA
TO THE PENNYRILE REGION OF W KY.
AT MID AFTERNOON...SATELLITE AND SURFACE OBSERVATIONS INDICATED
SKIES REMAINED MOSTLY CLEAR AHEAD OF THIS SYSTEM. A MID LEVEL CLOUD
BAND EXTENDED FROM CENTRAL MO TO SOUTHERN IN AND WAS
MOVING/DEVELOPING SLOWLY SOUTHWARD. RADAR SHOWED A LINE OF SHOWERS
DEVELOPING FROM W TO E ABOUT 50 MILES N OF EVV. SURFACE WINDS WERE
GUSTING ABOVE 20 KNOTS FROM THE SOUTHWEST WHICH WILL SUPPORT ENOUGH
MOISTURE TRANSPORT TO HELP SUPPORT THE SMALL RAIN CHANCES. SURFACE
DEWPOINTS HAD INCREASED ABOUT 5 DEGREES OVER THE SOUTHERN HALF OF
THE FA IN JUST A FEW HOURS. SCATTERED CU HAD DEVELOPED IN RESPONSE
TO THE LOW LEVEL MOISTURE INCREASE AND HEATING.
THE 500MB NORTHWEST FLOW CONTINUES FOR THE NEXT SHORT WAVE MON-TUE.
THIS SYSTEM MAY BE A BIT MORE SUPPORTIVE OF RAINFALL...WITH THE BEST
CHANCE AGAIN BEING OVER SW IN.
RAISED TONIGHT`S MIN TEMPS ACROSS THE NORTH AND EAST A COUPLE
DEGREES ALTHOUGH VALUES ARE STILL GENERALLY AT OR BELOW GFS MOS
VALUES PER PREVIOUS NIGHTS MATCH OF ACTUAL MINS AVERAGING 1 TO 2
DEGREES COOLER. WILL MAINTAIN SUN MAX TEMPS AOB MOS VALUES GIVEN NW
FLOW AND SOME LINGERING CLOUDS...ESPECIALLY SE.
LONG TERM...
THE EXTENDED CONTINUES TO BE A CHALLENGE. ON TUESDAY...NAM HAS US
DRY...THE ECMWF FOCUSES LIGHT QPF OVER NORTHEAST AREAS...AND GFS
SHOWS LIGHT QPF ACROSS THE ENTIRE PAH FORECAST AREA. WENT THE
COMPROMISE SOLUTION OF THE ECMWF AND INCLUDED JUST SLIGHT CHANCE
POPS FOR OUR NORTHEAST AREAS ON TUESDAY. GFS AND ECMWF ACTUALLY
AGREE ON DRY CONDITIONS TUESDAY NIGHT INTO WEDNESDAY. BY WEDNESDAY
NIGHT...ECMWF IS A LITTLE QUICKER THAN THE GFS BRINGING LIGHT QPF TO
THE AREA. KEPT US DRY WEDNESDAY NIGHT FOR NOW DUE TO TIMING
UNCERTAINTIES AND MODEL INCONSISTENCY. ON THURSDAY...GFS AND ECMWF
LINE UP A LITTLE BETTER...THOUGH GFS INDICATES HIGHER QPF AS A WARM
FRONT APPROACHES THEN STALLS JUST SOUTHWEST OF OUR REGION. WENT
WITH SLIGHT CHANCE POPS FOR THE ENTIRE PAH FA FOR THURSDAY...AND
CONTINUED THE SLIGHT CHANCE POPS ACROSS THE ENTIRE FA FOR THURSDAY
NIGHT.
ON FRIDAY...THE GFS AND ECMWF REALLY DIVERGE AS THE ECMWF
AGGRESSIVELY BUILDS HIGH PRESSURE OVER THE REGION AND KEEPS IT OVER
THE AREA INTO THE WEEKEND...WHILE THE GFS NEVER REALLY SHOWS THE
HIGH TAKING HOLD OF OUR REGION. THOUGH BELIEVE ECMWF BUILDS THE
HIGH IN TOO QUICKLY...PREFER ITS SOLUTION AS WE GET INTO THE
WEEKEND. FOR FRIDAY KEPT SLIGHT CHANCE POPS PER THE GFS...BUT WENT
WITH A DRY FORECAST FRIDAY NIGHT AND SATURDAY. OVERALL...EXTENDED
IS STILL FAIRLY LOW CONFIDENCE...ESPECIALLY BY THURSDAY ONWARD.
FOR TEMPS...MEX IS TRENDING QUITE A BIT COOLER THAN ITS PREVIOUS
RUN. DO LIKE THE COOLING TREND...THOUGH PREFER NOT TO GO QUITE AS
COOL AS THIS LATEST MEX RUN. OVERALL STAYED SEVERAL DEGREES ABOVE
THESE LATEST VALUES AND WILL SEE WHAT LATER RUNS BRING.
AVIATION...
VFR CIGS ARE EXPECT WITH COLD FRONT PASSAGE OVERNIGHT. A MID LEVEL
CLOUD BAND ASSOCIATED WITH THE FRONT MAY GENERATE SOME LIGHT SHOWERS
OR SPRINKLES TONIGHT AT KEVV AND KOWB. SW WINDS OF 10 TO 20 KNOTS
WILL DECREASE TO 5 TO 10 KNOTS OVERNIGHT BEFORE BECOMING NW AND
INCREASING TO 10 TO 15 KNOTS SUN MORNING. THERE IS ANOTHER CHANCE OF
SHOWERS FOR MON-TUE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
MO...NONE.
IL...NONE.
IN...NONE.
&&
$$
.SHORT TERM AND AVIATION...SHANKLIN
.LONG TERM...RST
