000
FXUS61 KILN 032204
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
504 PM EST WED DEC 3 2008
.SYNOPSIS...
A LARGE UPPER TROUGH WILL SETTLE ACROSS THE CENTRAL PLAINS. AN
UPPER LEVEL DISTURBANCE WILL ROUND THE BASE OF THE TROUGH AND MOVE
INTO THE GREAT LAKES TONIGHT...SENDING A QUICK-MOVING COLD FRONT
THROUGH THE OHIO VALLEY LATE TONIGHT. THE UPPER TROUGH WILL CONTINUE TO
INFLUENCE MUCH OF THE REGIONS WEATHER THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPPER LEVEL FLOW HAS BACKED AHEAD OF A MID/UPR LEVEL TROF. A QUICK
SHOT OF ISENTROPIC LIFT HAS LEAD TO SCATTERED SHOWERS ACROSS THE
REGION. THIS LIFT QUICKLY SHIFTS EAST BY LATE EVENING. THESE SHOWERS
ARE NOT ASSOCIATED WITH THE DEEPEST MSTR. DEEPER MSTR COMES INTO PLAY
LATE EVENING INTO THE OVERNIGHT HOURS. ALL FACTORS ARE NOT IN
PHASE WITH THE FORCING LIMITED TO THE LOWER LEVELS. STILL EXPECT TO
SEE WIDESPREAD SHOWER ACTIVITY...BUT GENERALLY EXPECT PRECIP TO BE
LESS THAN A QUARTER OF AN INCH. EXPECT THE BEST COVERAGE OF
PRECIP TO OCCUR WITH THE PASSAGE OF A COLD FRONT OVERNIGHT. THIS
FRONT IS EXPECTED TO REACH THE NORTHWEST CWA BY 06Z...THE I-71
CORRIDOR BY 06Z-08Z AND THE SOUTHEAST CWA AROUND 12Z. VERTICAL TEMP
PROFILES SUGGEST ALL RAIN WITH A BRIEF CHANGE TO SNOW PRIOR TO ENDING.
DO NOT EXPECT ANY ACCUM OTHER THAN A LIGHT DUSTING. TEMP WISE...HAVE
TRENDED TONIGHTS LOWS SLIGHTLY ABOVE MAV GUIDANCE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
WITH FRONT EXITING THE FAR SOUTHEAST AROUND 12Z THURSDAY MORNING...
EXPECT RAIN/SNOW MIX TO END EARLY. BROAD MID/UPPER LEVEL TROF TO SETTLE
INTO THE GREAT LAKES WITH SURFACE HIGH PRESSURE NOSING INTO THE OHIO
VALLEY. DEEPER MOISTURE WILL EXIT BUT WILL HOLD ONTO LOW CLOUDS A LITTLE
LONGER WITH PARTIAL CLEARING EXPECTED TO TAKE PLACE DURG THE AFTERNOON.
DEEP CAA WILL KEEP TEMPS FROM RISING VERY MUCH ON THURSDAY. HAVE TRENDED
THURSDAYS HIGHS SLIGHTLY BELOW MAV NUMBERS.
SURFACE HIGH PRESSURE TO SETTLE IN THURSDAY NIGHT AND FRIDAY WITH
MUCH BELOW AVG TEMPS CONTINUING THROUGH THE PERIOD. SHEARED OUT UPPER
TROUGH WHICH WILL DROP THROUGH THE REGION ON FRIDAY...WILL ONLY
RESULT IN SOME CLDS. HAVE TRENDED THURSDAY NIGHT AND FRIDAYS TEMPS
A LTL BELOW MAV READINGS. HAVE ALLOWED FOR AN INCREASE IN CLDS LATER
FRIDAY NIGHT WITH FLOW BACKING AHD OF CLIPPER TYPE SYSTEM DROPPING
INTO THE UPPER MS VLY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
CLIPPER MOVING THROUGH THE GREAT LAKES WILL BRING A GOOD CHANCE FOR
SNOW SHOWERS SATURDAY WITH ACTIVITY DIMINISHING ON SUNDAY. HIGH
PRESSURE TRAVELING ACROSS KENTUCKY WILL PROVIDE A PERIOD OF DRY
WEATHER ON MONDAY. A FRONT MAY SUPPLY RAIN AND SNOW SHOWERS ON
TUESDAY...CHANGING TO ALL SNOW BEFORE ENDING ON WEDNESDAY.
EXPECT TEMPERATURES TO REMAIN BELOW NORMAL THROUGH THE PERIOD. HIGHS
IN THE 30S ARE FORECAST FOR SATURDAY AND SUNDAY...WITH LOW 40S
CREEPING INTO THE SOUTH ON MONDAY. MOST LOCATIONS WILL REACH THE 40S
ON TUESDAY...BEFORE READINGS SLIP BACK INTO THE 30S FOR WEDNESDAY.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
A COLD FRONT WILL SWEEP ACROSS THE TAF SITES BETWEEN 06Z AND 10Z.
WARM...MOIST ASCENT...LOW LEVEL CONVERGENCE...AND SOME UPPER LEVEL
LIFT FROM A JET WILL PRODUCE WIDESPREAD SHOWERS ACROSS THE REGION.
MVFR CIGS AND VSBYS ARE EXPECTED WITH THE SHOWERS. COLD AIR AND
PRECIPITATION WILL END QUICKLY AFTER FRONTAL PASSAGE. THERE MAY BE
A BRIEF PERIOD OF RAIN/SNOW MIX OR JUST SNOW BEHIND THE FRONT.
HOWEVER...THIS SHOULD BE ABOUT AN HOUR OR LESS AND THUS HAVE NOT
ACCOUNTED FOR THIS CHANGEOVER IN THE TAFS AT THIS TIME. NEXT TAF
ISSUANCE OR MESOSCALE AMENDMENTS WILL BE ABLE TO PINPOINT THIS
BETTER. OTHERWISE...SHALLOW LOW LEVEL MOISTURE WILL LINGER ACROSS
THE FORECAST AREA THROUGH 00Z FRIDAY...KEEPING MVFR CIGS IN PLACE.
THERE COULD BE A PERIOD OF IFR CIGS BEHIND THE FRONT...BUT DO NOT
HAVE HIGH CONFIDENCE ATTM TO INCLUDE.
OUTLOOK...MVFR CIGS EXPECTED TO LINGER THROUGH THURSDAY EVENING. MVFR
CIGS AND VSBYS WILL BE POSSIBLE SAT THROUGH SUN.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...HICKMAN