FXUS63 KPAH 052334
AFDPAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
533 PM CST SAT DEC 5 2009
.UPDATE...
UPDATED AVIATION SECTION FOR 00Z TAF PACKAGE.
&&
.DISCUSSION...
SEVERAL CHALLENGES WITH THIS PACKAGE...NAMELY POPS AND PRECIP TYPE
ASSOCIATED WITH THREE WEATHER SYSTEMS THAT WILL AFFECT THE REGION
OVER THE NEXT SEVEN DAYS.
THE BACK SIDE OF AN AREA OF HIGH PRESSURE WEDGED ACROSS THE AREA
SHOULD KEEP US DRY WITH BELOW NORMAL TEMPERATURES THROUGH SUNDAY.
IN THE NEAR ZONAL FLOW ALOFT...A FAST MOVING SYSTEM (#1) WILL
CROSS THE HEARTLAND SUNDAY NIGHT INTO MIDDAY MONDAY. LATEST MODEL
RUNS NOW INDICATING SLIGHTLY BETTER UPPER SUPPORT WITH THIS
SYSTEM. SUNDAY EVENING (00-06Z) THE LATEST MODEL RUNS ONLY SATURATE
THE LOWER LEVELS OF THE ATMOSPHERE OVER OUR FAR NORTHWESTERN
COUNTIES. IN THESE AREAS...FORECAST SOUNDINGS ARE INDICATING
TEMPERATURES SO CLOSE AND PARALLEL TO THE ZERO DEGREE
ISOTHERM...PRECIP COULD BE SLEET OR SNOW. ELSEWHERE SUNDAY EVENING
PRECIP SHOULD BE ALL LIQUID.
SUNDAY NIGHT AFTER MIDNIGHT (06-12Z MONDAY) THE LOWER LEVELS OF
THE ATMOSPHERE COOL ENOUGH TO PRODUCE SNOW...BUT BY THEN MOISTURE
IS VERY LIMITED IN THE -10 TO -20C LAYER...SO ANY ICE NUCLEATION
WILL BE LIMITED...SO WENT WITH A RAIN/SNOW MIX OVER THE NORTHWEST
HALF OF THE CWA WITH RAIN ELSEWHERE.
MONDAY MORNING ON THE BACK SIDE OF THIS SYSTEM...MEASURABLE
LIQUID PRECIP COULD LINGER INTO THE EASTERN PORTIONS OF THE CWA.
RAIN MAY MIX WITH SNOW ALONG AND NORTH OF THE OHIO RIVER. FOR THE
REST OF THE CWA FLURRIES ARE POSSIBLE EXCEPT FOR FAR WESTERN SEMO.
BY MONDAY AFTERNOON ALL PRECIP SHOULD BE ENDED.
AFTER A BRIEF RESPITE...PRECIP CHANCES RETURN TO THE FORECAST ON
TUESDAY AS THE NEXT STORM SYSTEM (#2) BEGINS TO AFFECT THE REGION.
TODAYS MODEL RUNS ARE IN MUCH BETTER AGREEMENT WITH THE TIMING AND
TRACK OF THIS SYSTEM. MODELS NOW GENERALLY TAKE THE SURFACE LOW
NORTHEAST FROM THE PANHANDLE OF OKLAHOMA (00Z WED) TO WEST CENTRAL
INDIANA (12Z WED) TO EAST CENTRAL MICHIGAN (00Z THUR). THIS TRACK
KEEPS TEMPERATURES IN THE LOWER LEVELS OF THE ATMOSPHERE AOA 0C
OVER OUR CWA THUS YIELDING LIQUID PRECIP THROUGH MIDDAY WEDNESDAY.
AS THE COLDER (<0C) AIR OVERSPREADS THE REGION WEDNESDAY
AFTERNOON... MOISTURE IN THE ICE NUCLEATION LAYER IS GONE SO ONLY
EXPECT FLURRIES.
HIGH PRESSURE TO KEEP THE REGION DRY THROUGH THURSDAY NIGHT. ON
FRIDAY THE NEXT SYSTEM (#3) WILL BEGIN TO AFFECT THE REGION. AT
THIS TIME MODEL SOUNDINGS NOT IN SUCH GOOD AGREEMENT WITH REGARD
TO PRECIP TYPE...SO WILL JUST GO WITH A RAIN/SNOW MIX EVERYWHERE BOTH
FRIDAY AND FRIDAY NIGHT.
FOR TEMPERATURES IN THE SHORT TERM..CONTINUED TO SHADE TOWARD THE
COOLER SIDE OF GUIDANCE. WHEW!
&&
.AVIATION...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD. CALM TO LIGHT
SOUTHEAST WINDS OVERNIGHT WILL INCREASE TO AROUND 6 KTS AFTER 13Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
MO...NONE.
IL...NONE.
IN...NONE.
&&
$$
