275
FXUS63 KLMK 211535
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1035 AM EST SAT DEC 21 2024
KEY MESSAGES
* FEW LINGERING SNOW FLURRIES EARLY THIS MORNING. SLICK SPOTS WILL
BE POSSIBLE THIS MORNING.
* COLDER THAN NORMAL TEMPERATURES THROUGH THE WEEKEND.
* ABOVE NORMAL TEMPERATURES TUESDAY THROUGH FRIDAY. RAIN CHANCES
THROUGH THE WEEK, BUT LOW CONFIDENCE REGARDING TIMING.
UPDATE
ISSUED AT 1035 AM EST SAT DEC 21 2024
HIGH PRESSURE BUILDING IN FROM THE NORTH, OUT OF THE UPPER MIDWEST.
STRONG COLD AIR ADVECTION ALONG WITH DRIER AIR HAS ALLOWED FOR LOW
STRATUS TO CLEAR OUT A LITTLE FASTER THAN FIRST THOUGHT. EVEN WITH
MORE SUNSHINE, GIVEN THE LOW SUN ANGLE AND STRONG CAA DECIDED TO
KEEP FORECAST HIGHS THE SAME. THE ONLY CHANGES TO THE FORECAST GRIDS
WERE TO UPDATE THE CLOUD COVER TO BETTER REPRESENT THE CLEARING.
OTHER THAN THAT NO OTHER CHANGES TO THE FORECAST EXPECTED.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 259 AM EST SAT DEC 21 2024
CURRENTLY, RADAR SHOWS VERY FAINT ECHOES ALONG I-65 FROM A FETCH
ORIGINATING OFF LAKE MICHIGAN. THESE LIGHT FLURRIES WILL DISSIPATE
WITHIN THE NEXT FEW HOURS. A FEW SLICK SPOTS WILL BE POSSIBLE ON
ROADS THIS MORNING. ADDITIONALLY, LOW-LEVEL MOISTURE TRAPPED BENEATH
A PRONOUNCED SUBSIDENCE AND UPPER NORTHWESTERLY FLOW HAS RESULTED IN
SHALLOW LOW STRATUS STREAMING OVER THE REGION. THROUGH THE MORNING,
THESE CLOUDS WILL SLOWLY THIN AS UPPER TROUGHING CONTINUES TO PUSH
OFF TO THE NORTHEAST AND SURFACE HIGH PRESSURE BUILDS INTO THE
REGION.
CAA WILL CONTINUE TO FILTER INTO THE REGION KEEPING 850MB TEMPS IN
THE -8 TO -12C RANGE. SURFACE TEMPERATURES WILL BE IN THE UPPER 30S
OVER THE SOUTHWEST AND MID 30S OVER THE BLUEGRASS.
IN THE EVENING, THE HIGH PRESSURE CENTER WILL DRIFT OVER THE
SOUTHERN GREAT LAKES REGION ALLOWING OHIO VALLEY SURFACE WINDS TO
RELAX AND VEER TO THE EAST BY SUNDAY MORNING. WITH LIGHT, EASTERLY
WINDS AND MOSTLY CLEAR SKIES, WE ARE EXPECTED TO DECOUPLE IN THE
OVERNIGHT HOURS, ALLOWING TEMPERATURES TO FALL INTO THE UPPER TEENS
AND LOW 20S OVER THE BLUEGRASS AND LOW-MID 20S ELSEWHERE.
LONG TERM /SUNDAY THROUGH FRIDAY/
ISSUED AT 259 AM EST SAT DEC 21 2024
COLD AND DRY HIGH PRESSURE ON SUNDAY WILL RETREAT EASTWARD, MAKING
ITS WAY TO THE NEW ENGLAND AND MID-ATLANTIC COAST BY MONDAY MORNING.
TEMPS ON SUNDAY WILL BE SOLIDLY BELOW NORMAL UNDER THE LOW-LEVEL
THERMAL TROF, BUT SUNSHINE AND LIGHT WINDS WILL EASE THE WINTER
FEEL.
AFTER ONE LAST COLD NIGHT ON SUNDAY NIGHT, THE WARMING TREND BEGINS
MONDAY AS RETURN FLOW BEGINS TO SET UP. TEMPS RECOVER TO JUST ABOVE
CLIMO MONDAY AFTERNOON, AND ANY PRECIP CHANCES HOLD OFF UNTIL AT
LEAST THE EVENING.
PROGRESSIVE UPPER PATTERN SETS UP FOR THE REST OF THE WEEK, BUT
PRECIP CHANCES AND QPF REMAIN FAIRLY LACKLUSTER AS LOW-AMPLITUDE
RIDGING OVER THE SE CONUS WILL GUIDE MOST OF THE DISTURBANCES TO OUR
NORTH AND WEST. HIGH CONFIDENCE THAT TEMPS WILL RUN SOLIDLY ABOVE
NORMAL THROUGH THE PERIOD, WITH HIGHS GENERALLY IN THE 50S AND LOWS
IN THE 40S. THERE WILL BE MULTIPLE OPPORTUNITIES FOR PRECIP, BUT
TIMING IS DIFFICULT AND QPF IS QUITE MODEST GIVEN WEAK FORCING. WILL
KEEP POPS IN THE CHANCE (30-50%) CATEGORY FOR INTERVALS OF LIGHT TO
PERHAPS MODERATE RAIN, BUT ALSO SUBSTANTIAL DRY PERIODS IN BETWEEN.
AVIATION /12Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 543 AM EST SAT DEC 21 2024
AS LARGE UPPER TROUGHING MOVES OFF TO THE NORTHEAST, THE OHIO VALLEY
REMAINS WITHIN NORTHWEST FLOW. MOISTURE TRAPPED UNDER A PRONOUNCED
SUBSIDENCE INVERSION HAS ALLOWED TO SHALLOW LOW LEVEL CLOUDS TO
PERSIST OVER THE REGION. THESE CLOUDS WAVER FROM VFR TO HIGH-END
MVFR AND ARE BEGINNING TO THIN AND PUSH SOUTH OF THE REGION.
WINDS WILL SLOWLY BEGIN TO RELAX AS HIGH PRESSURE PUSHES TIGHT
PRESSURE GRADIENTS OUT OF THE REGION. TONIGHT, WINDS WILL BEGIN TO
VEER TO THE EAST AS HIGH PRESSURE MOVES OVER THE GREAT LAKES REGION.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
UPDATE...BTN
SHORT TERM...SRM
LONG TERM...RAS
AVIATION...SRM
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