FXUS61 KILN 272153
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
453 PM EST FRI NOV 27 2009
.SYNOPSIS...
HIGH PRESSURE WILL THEN BUILD INTO THE REGION LATE THIS AFTERNOON
AND WILL CONTROL THE REGIONS WEATHER INTO EARLY SUNDAY. A COLD
FRONT WILL MOVE INTO THE OHIO VALLEY BRINGING THE NIGHT CHANCE OF
RAIN ON SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
HIGHLY AMPLIFIED UPPER LEVEL FLOW PATTERN WITH LOW PRESSURE OVER
THE EASTERN GREAT LAKES SHIFTING EAST AS LARGE RIDGE BEGINS TO
BUILD EAST FROM THE NATIONS MID SECTION. SFC RIDGE TO BEGIN BUILDING
IN THIS EVENING. WITH LOW LEVEL FLOW TRANSITIONING FROM CYCLONIC TO
ANTI-CYCLONIC EXPECT CLDS TO CLEAR FROM THE SOUTHWEST. WITH CLEARING
SKIES AND LIGHT WINDS HAVE TRENDED OVERNIGHT LOWS ON THE COOL SIDE
OF GUIDANCE ENVELOPE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
IN AMPLIFIED SPLIT LEVEL FLOW PATTERN UPPER LEVEL RIDGING WL BUILD
OVER THE REGION ON SATURDAY. EXPECT TO SEE A GOOD AMOUNT OF SUNSHINE
WITH MODERATING TEMPERATURES. HAVE TRENDED SATURDAYS HIGHS CLOSER
TO COOLER MAV NUMBERS.
THE FLOW BACKS WITH AN INCREASE IN CLOUDS LATE SATURDAY NIGHT INTO
SUNDAY. HAVE TRENDED SAT NIGHTS LOWS A LTL COOLER THAN GUID BASED
ON EXPECTED SLOWER ONSET OF CLDS.
WEAK ISENTROPIC LIFT DEVELOPS AHEAD OF AN APPROACHING COLD FRONT
ON SUNDAY. NUMERICAL MODEL SOLN/S A LTL SLOWER AND THEREFORE HAVE
SPREAD CHC POPS FOR SHOWERS INTO THE NW SUNDAY AFTN AND THEN INCREASE
POPS TO LIKELY OVERNIGHT SUNDAY. HAVE ENDED POPS FROM THE NW
MONDAY IN THE WAKE OF THE FRONT. SFC HIGH PRESSURE TO RESULT IN
DRY WEATHER MONDAY NIGHT.
HAVE TRENDED SUNDAYS HIGHS A LTL BELOW GUID DUE TO CLDS AND PRECIP
AND SLIGHT ABOVE SUNDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
IN SPLIT UPPER LEVEL FLOW PATTERN CONFLUENCE OVER THE REGION RESULTING
IN SFC RIDGING. THIS WILL PROVIDE GENERALLY DRY WEATHER TUESDAY INTO
EARLY WEDNESDAY.
SRN STREAM SYSTEM TO EJECT FROM THE GULF STATES NE INTO THE OHIO
VLY AND MERGE WITH THE NORTHERN STREAM AS A BROAD TROF DEVELOPS ACROSS
THE GREAT LAKES. LATEST GFS SOLN KEEPS THIS SYSTEM FAR TO OUR EAST
WHILE THE MORE CONSISTENT ECMWF AND ENSEMBLES BRING IT INTO THE OHIO
VALLEY. WL FOLLOW THESE SOLN/S SPREADING CHC POPS FOR RAIN SHOWERS
FROM THE SOUTH WEDNESDAY AFTN. WL CONT CHC POPS INTO THURSDAY MORNING
WHEN A COLD FRONT IS EXPECTED TO PASS THRU.
WITH BROAD TROF UPR LEVEL ACRS THE GREAT LAKES...SFC HIGH PRESSURE
EXPECTED TO NOSE INTO THE TN VLY LATER THURSDAY INTO FRIDAY. HAVE
MAINTAINED A DRY FCST THRU THE END OF THE WEEK WITH TEMPS BELOW
NORMAL.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
CLOUDS LINGERING IN CAA BEHIND TROUGH. SOME MVFR CEILINGS BUT
SLOWLY RISING HEIGHTS. DRYING SHOULD BEGIN CLEARING THIS EVENING
WITH HIGH PRESSURE BUILDING IN THROUGH TAF PERIOD. WINDS LESSEN AS
GRADIENT RELAXES THIS EVENING. SOME BRIEF FOG NEAR SUNRISE AT LUK
BUT NOT INCLUDED SINCE IT SHOULD NOT BE WORSE THAN BRIEF MVFR VSBY.
HIGH SHIFTS EAST SATURDAY WITH ONLY HIGH CLOUDS EXPECTED. CONTINUED
OUTLOOK...MVFR CIGS AND VSBYS POSSIBLE SUNDAY NIGHT/MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...AR
AVIATION...JDR