FXUS63 KLMK 111718
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1218 PM EST FRI DEC 11 2009
...UPDATED AVIATION DISCUSSION...
.SHORT TERM (TODAY AND TONIGHT)...
SURFACE HIGH PRESSURE WILL MOVE EASTWARD ACROSS THE REGION TODAY.
OTHER THAN A FEW HIGH CLOUDS MOVING THROUGH THIS MORNING...THE DAY
SHOULD BE MOSTLY SUNNY. TEMPERATURES WILL START OUT COLD THIS
MORNING IN THE TEENS BUT SOME WARM AIR ADVECTION WILL ENCROACH INTO
THE AREA AS THE HIGH SCOOTS TO THE NORTHEAST AND GIVEN LOTS OF SUN
TODAY HIGHS WILL REBOUND INTO THE MID AND UPPER 30S NORTH TO THE LOW
40S SOUTH.
LIGHT SOUTHWEST WINDS TODAY WILL BECOME SOUTHEASTERLY AFTER SUNSET.
GIVEN ANOTHER MOSTLY CLEAR NIGHT TONIGHT AND LIGHT
WINDS...TEMPERATURES WILL ONCE AGAIN BE COLD BUT NOT AS COLD AS THE
PREVIOUS COUPLE OF NIGHTS. LOWS WILL FALL INTO THE LOW 20S IN MOST
LOCATIONS ALTHOUGH SOME SHELTERED LOCATIONS COULD SEE UPPER TEENS
ONCE AGAIN.
.LONG TERM (SATURDAY - THURSDAY)...
SATURDAY THROUGH MONDAY NIGHT...
LATEST MODELS ARE IN GOOD AGREEMENT THROUGH THIS TIME FRAME. AS SFC
HIGH PRESSURE DRIFTS OFF TO THE EAST ON SATURDAY...SOUTHWESTERLY
FLOW WILL BEGIN TO BRING WARMER AIR INTO THE REGION. AT THE SAME
TIME APPROACHING MID-LEVEL WAVE WILL PASS THROUGH THE REGION
BRINGING A GOOD SHOT OF PRECIPITATION TO THE REGION. LATEST TRENDS
IN THE MODEL SUGGEST PRECIPITATION HOLDING OFF UNTIL LATE SATURDAY
AFTERNOON AND THEN SPREADING NORTHEASTWARD SATURDAY NIGHT. BOTH THE
11/00Z EURO AND GFS AGREE ON THIS AND WE HAVE INCREASED POPS
SUBSTANTIALLY FOR SAT NIGHT AND INTO SUNDAY. THERMAL PROFILES START
OFF VERY CLOSE TO THE CRITICAL THICKNESSES BETWEEN LIQUID AND FROZEN
PRECIP. THIS ESPECIALLY TRUE ACROSS THE FAR NORTHERN SECTIONS OF
OUR CWA AS PRECIPITATION WILL BE FALLING THROUGH AN ANTECEDENT DRY
AIRMASS AND SOME EVAPORATE COOLING MAY RESULT IN A MIX OF
RA/FZRA/PL/SN INITIALLY. THE SREF ENSEMBLE PTYPES SHOW A SLIGHT
CHANCE OF THIS HAPPENING...BUT THE NAM-WRF PROFILES SHOW ONLY A VERY
THIN LAYER OF COLDER AIR NEAR THE SFC...WHICH MAY NOT BE ENOUGH FOR
EVAP COOLING PROCESSES TO BE REALIZED. GIVEN THE RECENT TRENDS...WE
ARE GOING TO LEAVE PRECIPITATION IN THE FORM OF RAIN FOR NOW...BUT
WILL CONTINUE TO MONITOR. EVEN IF THE PRECIPITATION SHOULD START
OFF AS MIX...IT WOULD NOT LAST VERY LONG AS SUBSTANTIAL WARMING IS
EXPECTED TO COMMENCE SAT NIGHT. HIGHS SAT AFTERNOON WILL WARM INTO
THE UPPER 30S IN THE NORTH AND LOWER 40S ACROSS THE SOUTH.
OVERNIGHT LOWS SAT NIGHT LOOK TO DROP INTO THE MID 30S.
PRECIPITATION WILL QUICKLY MOVE EAST OF THE REGION ON SUNDAY WITH A
DRYING TREND COMMENCING FROM WEST TO EAST DURING THE DAY. HIGHS
SUNDAY WILL WARM BACK INTO THE LOWER-MID 40S IN THE NORTH AND UPPER
40S IN THE SOUTH. DRY CONDITIONS ARE EXPECTED FOR SUNDAY NIGHT AND
THE FIRST PART OF MONDAY AS WEAK HIGH PRESSURE SLIDES THROUGH THE
REGION. LOWS SUNDAY NIGHT WILL DROP INTO THE UPPER 30S TO THE LOWER
40S. SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD FRONT WILL ALLOW
THE REGION TO REALLY WARM UP DURING THE DAY ON MONDAY. A SLIGHT CHC
OF SHOWERS STILL SEEMS REASONABLE GIVEN THE WAA PATTERN THAT WE'LL
BE IN. HIGHS WILL RANGE FROM THE UPPER 40S TO AROUND 50 IN THE
NORTH WITH LOWER-MID 50S ACROSS MUCH OF CENTRAL AND SOUTHERN KY.
STRONG COLD FRONT WILL PUSH THROUGH THE REGION MONDAY NIGHT WITH
SHOWERS ACCOMPANYING IT. TEMPERATURES WILL REMAIN MILD AHEAD OF THE
FRONT MONDAY NIGHT WITH LOWS OCCURING PROBABLY AROUND 12Z TUE.
TEMPS WILL CRASH BEHIND THE FRONT WITH TEMPERATURES FALLING TO
AROUND FREEZING IN THE FAR NW BY 12Z TUE AND UPPER 30S TO LOWER 40S
ACROSS THE CENTRAL AND EASTERN SECTIONS.
TUESDAY THROUGH THURSDAY...
SFC COLD FRONT WILL CONTINUE TO PUSH EASTWARD DURING THE DAY AND
MUCH DRIER AND COLDER AIR WILL RUSH INTO THE REGION DURING THE DAY
ON TUESDAY. THERE IS A BIT OF DISAGREEMENT WITH THE COLD PUSH
BEHIND THE FRONT AS THE GFS IS THE COLDEST MEMBER OF THE ENSEMBLES
HERE AND THE EURO RUNS ARE MUCH WARMER. FOR NOW...HAVE GONE WITH A
50/50 EURO/GFS BLEND HERE FOR TEMPS WITH HIGHS IN THE LOWER-MID 30S
IN THE NW TUE WITH UPPER 30S/LOWER 40S ELSEWHERE. MUCH COLDER AND
DRIER CONDITIONS LOOK TO BE ON TAP FOR TUE NIGHT AND WED WITH TUE
NIGHT TEMPS DROPPING INTO THE MID-UPPER TEENS IN THE NORTH AND UPPER
TEENS TO THE LOWER 20S ACROSS THE SOUTH. HIGHS WEDNESDAY WILL BE
WELL BELOW NORMAL WITH HIGHS IN THE UPPER 20S TO THE LOWER 30S IN
THE NORTH AND LOWER-MID 30S ACROSS THE SOUTH. A SLIGHT MODERATION
IN TEMPS IS POSSIBLE BY THU WITH HIGHS WARMING IN THE LOWER 30S IN
THE NORTH AND MID-UPPER 30S IN THE SOUTH.
&&
.AVIATION (18Z TAF ISSUANCE)...
VFR CONDITIONS WILL CONTINUE THROUGH THIS TAF PERIOD. SFC HIGH
PRESSURE IS CURRENTLY OVERHEAD S-CNTRL KY...AND WILL MOVE SLOWLY TO
THE EAST BY 12Z SATURDAY...VEERING OUR SFC WINDS AROUND TO THE SE BY
THAT TIME. ANY MID-LEVEL CLOUDS OUT THERE NOW ARE WANING...AND SKIES
WILL BE CLEAR SHORTLY. OTHERWISE...AFTER 12Z SAT...MID-LEVEL
CLOUDINESS WILL FILTER IN FROM THE SOUTH AS A DISTURBANCE OVER THE
GULF STATES MOVES UP TOWARD THE MID-ATLANTIC COAST. THIS WILL
EVENTUALLY BRING -RA TO THE TERMINALS...BUT NOT DURING THIS TAF
PERIOD. SSE SFC WINDS WILL INCREASE TOWARD 15-18Z SAT TO 10-15 KTS.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
SHORT TERM........LMS
LONG TERM.........MJ
AVIATION..........AL
