FXUS63 KLMK 061702
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1202 PM EST SUN DEC 6 2009
...UPDATED AVIATION DISCUSSION...
...FORECAST UPDATE...
ONLY A MINOR UPDATE THIS MORNING TO ADJUST TEMPS UP IN THE WESTERN
FORECAST AREA (FA) AND TWEAK SKY GRIDS. WITH HIGH PRESSURE CENTERED
TO OUR EAST OVER SOUTHERN OHIO AND WEST VIRGINIA...TODAY WILL BE A
QUIET WEATHER DAY. UPPER LEVEL CLOUDS WILL GRADUALLY INCREASE FROM
SW TO NE TODAY AND HAVE TWEAK SKY GRIDS TO SHOW THIS TREND FOR THIS
AFTERNOON. HOWEVER...CLOUD DECK SHOULD STAY TRANSPARENT ENOUGH TO
ALLOW PLENTY OF SUNSHINE THROUGH. SINCE MORNING TEMPS HAVE RISEN A
BIT MORE IN THE WESTERN FA THAN PREVIOUSLY FORECAST...HAVE UPPED
HIGHS A DEGREE OR TWO IN THIS AREA. GENERALLY WE SHOULD SEE HIGHS IN
THE LOW TO MID 40S THIS AFTERNOON.
.SHORT TERM (TODAY THROUGH MONDAY)...
UPPER AIR FLOW CURRENTLY SHOWS A BLOCKING RIDGE OVER SOUTHERN ALASKA
WITH DEEP COLD TROUGHS BRACKETING THIS RIDGE LOCATED ACROSS THE
PACIFIC NORTHWEST AND SOUTH OF THE WESTERN ALEUTIANS. AS ARCTIC AIR
POURS INTO THE PACIFIC NORTHWEST...THIS TROUGH WILL SAG SOUTHWARD
TOWARDS NORTHERN CALIFORNIA BY MONDAY AFTERNOON. A SHORTWAVE TROUGH
NOW OVER THE CENTRAL ROCKIES WILL DE-AMPLIFY AND WEAKEN AS IT
CROSSES MISSOURI LATE SUNDAY.
THE SURFACE REFLECTION OF THIS SYSTEM WILL BE WEAK...BUT WILL SHOW
UP AS AN INVERTED SURFACE TROUGH OVER MISSOURI EARLY MONDAY.
EXPECT A MOSTLY SUNNY DAY WITH SOME INCREASING HIGH CLOUDINESS THIS
AFTERNOON AS A SEASONABLY COLD AIR MASS REMAINS OVER THE LOWER OHIO
VALLEY. HIGH PRESSURE RIGHT OVERHEAD ATTM WILL MOVE EAST TOWARDS THE
MID ATLANTIC COAST BY THIS EVENING. SURFACE WINDS WILL BECOME LIGHT
SOUTHERLY THIS AFTERNOON. AFTER A COLD START...TEMPS SHOULD MODERATE
A BIT INTO THE LOWER 40S THIS AFTERNOON.
EXPECT INCREASING CLOUDINESS THIS EVENING AS WARM AIR ADVECTION
STRENGTHENS AHEAD OF THE PREVIOUSLY MENTIONED INVERTED TROUGH OVER
MISSOURI. MOISTURE ASSOCIATED WITH THIS SYSTEM WILL BE SCANT.
HOWEVER...SOME SPRINKLES OR VERY LIGHT SNOW SHOWERS ARE POSSIBLE
TOWARDS DAWN ON MONDAY WEST OF INTERSTATE 65...AND LATER IN THE
MORNING ACROSS THE BLUEGRASS AND THE LAKE CUMBERLAND AREAS. FORECAST
SOUNDINGS SHOW MUCH OF THE ATMOSPHERE BELOW FREEZING...ALTHOUGH
SURFACE TEMPS MAY WARM TO A COUPLE OF DEGREES ABOVE FREEZING MONDAY
MORNING. VERY LIMITED MOISTURE WILL BE AVAILABLE IN THE PREFERRED
SNOW FORMATION REGIONS BETWEEN -10C AND -20C...AND SO DO NOT EXPECT
MUCH IN THE WAY OF ACCUMULATIONS. CLOUDS WILL LIKELY LIMIT HIGHS
MONDAY TO AROUND 40 OR SO. WINDS WILL STAY LIGHT MONDAY FROM THE
SOUTHWEST.
.LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...
TUESDAY AND WEDNESDAY...
A STRONG UPPER LEVEL JET ROTATING THROUGH THE BASE OF A WEST COAST
TROUGH AT THE BEGINNING OF THIS FORECAST PERIOD WILL QUICKLY
TRANSVERSE THE UNITED STATES... ARRIVING IN THE LOWER OHIO VALLEY BY
WEDNESDAY AFTERNOON. THIS WILL SERVE TO PUSH THE UPPER LEVEL TROUGH
QUICKLY INTO THE REGION. IN THE LOWER ATMOSPHERE A DEEPENING LOW
WILL TRACK FROM OKLAHOMA TUESDAY NIGHT INTO MICHIGAN BY WEDNESDAY
AFTERNOON. WITH A TIGHTENING SOUTHERLY GRADIENT AHEAD OF THE LOW
WARM MOIST AIR WILL STREAM INTO THE LOWER OHIO VALLEY WITH SHOWERS
OVERSPREADING THE FORECAST AREA TUESDAY AFTERNOON AND CONTINUING
TUESDAY NIGHT. STRONG LOW LEVEL WINDS SHOULD REMAIN ELEVATED MOST OF
TUESDAY NIGHT BUT SOME STRONG GUSTS MAY MAKE IT TO THE SURFACE
AROUND 12Z WEDNESDAY. A STRONG COLD FRONT WILL SWEEP THROUGH THE
REGION WEDNESDAY MORNING WITH GUSTY WESTERLY WINDS NOTED WEDNESDAY
AFTERNOON. LINGERING SHOWERS WILL GRADUALLY CHANGE TO LIGHT SNOW
SHOWERS BY AFTERNOON AS WELL.
TEMPERATURES WILL BE ON SOMEWHAT OF A ROLLER COASTER RIDE WITH THE
WARMEST READINGS NOTED JUST BEFORE THE FRONTAL PASSAGE WEDNESDAY
MORNING.
THURSDAY - SATURDAY...
YET ANOTHER SOUTHERN STREAM SYSTEM WILL AFFECT THE AREA ON FRIDAY
NIGHT/SAT. AT THIS POINT...IT DOES LOOK LIKE SOME FROZEN PRECIP
WOULD BE POSSIBLE. TEMPS LOOK TO REMAIN BELOW NORMAL IN THE LAST
PART OF THE LONG TERM.
&&
.AVIATION (18Z TAF ISSUANCE)...
VFR CONDITIONS EXPECTED THROUGH AROUND 12Z MONDAY. SFC HIGH PRESSURE
CENTERED OVER SOUTHERN OHIO AND WEST VIRGINIA EARLY THIS AFTERNOON
WILL CONTINUE TO MOVE EAST TODAY. A LOW PRESSURE SYSTEM WILL MOVE
NE OUT OF THE PLAINS TONIGHT PASSING TO OUR NW INTO THE GREAT LAKES.
THIS AFTERNOON EXPECT INCREASING HIGH CLOUDS OUT AHEAD OF THIS
SYSTEM. OVERNIGHT THE SYSTEM WILL WEAKEN AND LOSE MOISTURE...HOWEVER
AN ISLD CHANCE OF LIGHT RAIN OR SNOW SHOWERS DOES EXIST FROM ROUGHLY
9Z TO 18Z. WILL NOT MENTION IN THE TAFS HOWEVER GIVEN SUCH A SMALL
CHANCE. AS THE WEAK FRONTAL BOUNDARY WITH THIS SYSTEM PASSES THROUGH
OUR AREA TOMORROW AFTERNOON...WE/LL SEE AN INCREASE IN LL CLOUDS.
CIGS SHOULD DROP INTO THE MVFR CATEGORY FOR BWG AND SDF AT THE END
OF THIS TAF PERIOD...WITH LEX MVFR CIGS JUST BEYOND THIS TAF PERIOD.
AS FOR WINDS...THEY WILL REMAIN OUT OF THE SE THIS AFTERNOON AROUND
5-6 KTS. TOWARD MORNING...WINDS WILL TURN TO THE SOUTH AND THEN
TOMORROW AFTERNOON BEHIND THE BOUNDARY...SOUTHWEST. WINDS WILL
REMAIN BELOW 10KTS THROUGH TOMORROW AFTERNOON.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
UPDATE.........AML
SHORT TERM.....JSD
LONG TERM......JA
AVIATION.......AML
