927
FXUS63 KLMK 231043
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
643 AM EDT SAT OCT 23 2021
..UPDATED AVIATION DISCUSSION
SHORT TERM
(TODAY AND TONIGHT)
ISSUED AT 259 AM EDT SAT OCT 23 2021
PATCHY FOG HAS DEVELOPED EARLY THIS MORNING FROM THE LOWER WABASH
VALLEY INTO WESTERN KENTUCKY. THIS FOG IS EXPECTED TO DEVELOP
EASTWARD INTO PORTIONS OF CENTRAL KENTUCKY, ESPECIALLY THE BOWLING
GREEN/MAMMOTH CAVE REGION WHERE THERE WILL BE THE MOST FOG-FRIENDLY
COMBINATION OF CLEAR SKIES AND LIGHT WINDS. ANY PATCHY FOG WILL
DISSIPATE BY MID-MORNING.
OVER THE REMAINDER OF THE DAY A WARM FRONT WILL BECOME INCREASINGLY
MORE WELL-DEFINED AS IT DRIFTS NORTHWARD ACROSS KENTUCKY. BY THIS
EVENING IT SHOULD BE IN AN EAST-WEST ORIENTATION JUST NORTH OF THE I-
64 CORRIDOR. SFC-700MB MOISTURE WILL GRADUALLY INCREASE TODAY AND
SOME WEAK ISENTROPIC UPGLIDE WILL KICK IN THIS AFTERNOON, LEADING TO
THE DEVELOPMENT OF SCATTERED LIGHT RAIN SHOWERS BY MID-LATE
AFTERNOON. RAINFALL AMOUNTS SHOULD BE LESS THAN A TENTH OF AN INCH,
WITH THE MOST LIKELY AREA TO EXPERIENCE RAIN BEING WEST OF I-65 AND
NORTH OF I-165.
WITH THE SURFACE BOUNDARY IN THE AREA THERE WILL BE A NORTH-SOUTH
GRADIENT IN HIGH TEMPERATURES THIS AFTERNOON. MOST LOCATIONS WILL
HAVE A HIGH IN THE 60S, BUT SOME PLACES IN SOUTHERN INDIANA MAY NOT
MAKE IT OUT OF THE 50S WHILE A FEW FOLKS ALONG THE TENNESSEE BORDER
MAY SEE THE MERCURY TOUCH 70.
TONIGHT A BAND OF CONVECTION IS EXPECTED TO DEVELOP AFTER MIDNIGHT
FROM THE MIDWEST TO THE MIDDLE OHIO VALLEY. THIS ACTIVITY WILL BE IN
CONJUNCTION WITH THE AFOREMENTIONED SURFACE FRONT AND ON THE LEADING
EDGE OF A BROAD LOW LEVEL JET. THERE MAY BE ENOUGH INSTABILITY FOR A
FEW RUMBLES OF THUNDER DURING THE PRE-DAWN HOURS SUNDAY MORNING.
LOWS WILL BE IN THE 50S, 5 TO 10 DEGREES WARMER THAN NORMAL GIVEN
OUR POSITION IN THE WARM AIR SOUTH OF THE SURFACE BOUNDARY AND WITH
WIDESPREAD CLOUD COVER.
LONG TERM
(SUNDAY THROUGH FRIDAY)
ISSUED AT 305 AM EDT SAT OCT 23 2021
SUNDAY - MONDAY...
A STORM SYSTEM OVER THE EAST CENTRAL PLAINS WILL MOVE INTO THE MID
MISSISSIPPI RIVER VALLEY BY LATER SUNDAY, AND THEN THROUGH THE
WABASH RIVER VALLEY BY LATE MONDAY. THE ASSOCIATED WARM FRONT WITH
THIS SYSTEM WILL BE LIFTING ACROSS OUR NORTHERN CWA AT DAYBREAK
SUNDAY BRINGING NUMEROUS SHOWERS AND ELEVATED THUNDERSTORMS, MAINLY
CONFINED TO THE NORTHERN HALF OF OUR AREA. BY LATER IN THE AFTERNOON
AND EVENING, WE'LL LIKELY SEE MOSTLY DRY CONDITIONS AS THE WARM
SECTOR WILL BE WELL ESTABLISHED OVER SOUTHERN IN AND CENTRAL KY.
TEMPS WILL EXCEL UNDER THIS REGIME GIVEN A GUSTY/MIXY SW SURFACE
FLOW AIDING THE ALREADY NOTABLE WARM ADVECTION COMPONENT. LOOK FOR
HIGHS IN THE MID TO UPPER 70S. A FEW SPOTS ACROSS OUR FAR SW COULD
FLIRT WITH THE 80 DEGREE MARK. LOOKS LIKE WE'LL SEE PRETTY GUSTY
GRADIENT WINDS WITH SOME 25-35 MPH VALUES CERTAINLY POSSIBLE.
THE RELATIVE LULL IN ACTIVITY WON'T LAST LONG AS THINGS WILL PICK UP
AROUND OR SHORTLY AFTER MIDNIGHT. THE EXIT REGION OF A 55 TO 65 KNOT
MID LEVEL IMPULSE WILL OVERSPREAD THE WARM SECTOR AHEAD OF AN
APPROACHING COLD FRONT. MEANWHILE, A HEALTHY 50 TO 55 KNOT LOW LEVEL
JET WILL BE IN PLACE. THIS WILL YIELD A STRONG AND VEERED VERTICAL
WIND PROFILE THAT WOULD BE MORE THAN SUFFICIENT FOR ORGANIZED SEVERE
WEATHER. HOWEVER, INSTABILITY IS EXPECTED TO BE MEAGER TO NON-
EXISTENT BY THE TIME CONVECTION ARRIVES/DEVELOPS IN OUR AREA THANKS
TO THE NOCTURNAL TIMING. AS A RESULT, EXPECT A WEAKENING TREND WITH
ANYTHING APPROACHING OUR AREA FROM THE WEST. AT THIS POINT, BELIEVE
GUSTY WINDS WOULD BE THE MAIN THREAT WITH ANY DECAYING STORMS, AND
SOME LOW LEVEL STABILITY WOULD KEEP A BIGGER THREAT MITIGATED. THE
COLD FRONT WON'T ACTUALLY MOVE THROUGH OUR AREA UNTIL LATER MONDAY,
SO YOU WOULD WANT TO KEEP AN EYE ON SOME INSTABILITY DEVELOPING
ACROSS OUR EAST MONDAY AFTERNOON. HOWEVER, GIVEN THE CLOUD
COVER/PRECIPITATION THINK THESE VALUES WOULD ALSO BE QUITE MEAGER.
ALSO OF NOTE, THE BEST SHEAR WILL BE DISPLACED FARTHER TO THE EAST
BY THIS TIME AS WELL. CAN'T COMPLETELY RULE OUT SOME SEVERE THREAT
EITHER SUNDAY NIGHT OR MONDAY, BUT AT THIS POINT IT SEEMS LESS
LIKELY GIVEN THE INABILITY TO DESTABILIZE BETTER. WILL CONTINUE TO
MONITOR. THE MARGINAL RISK ACROSS OUR WESTERN THIRD OF THE CWA SEEMS
REASONABLE.
MONDAY NIGHT - WEDNESDAY...
THE COLD FRONT AND SHORTWAVE WILL BE EXITING OUR EAST BY MONDAY
NIGHT WITH DRY CONDITIONS TAKING BACK AHOLD OF THE REGION.
INITIALLY, IT WILL BE DRY NW FLOW ALOFT AND BUILDING SURFACE HIGH
PRESSURE, HOWEVER THE PROGRESSIVE UPPER PATTERN WILL THEN SHIFT AN
AMPLIFIED UPPER RIDGE AXIS OVER OUR AREA LATER TUESDAY NIGHT THROUGH
WEDNESDAY. EITHER WAY, WE STAY DRY THROUGH THIS STRETCH. TEMPS WILL
BE A BIT COOLER BEHIND THE FRONT, BUT WE'LL STILL SEE LOW TO MID 60S
ON TUESDAY, AND 65 TO 70 DEGREES BY WEDNESDAY. OVERNIGHT LOWS WILL
BE IN THE MID TO UPPER 40S TO AROUND 50 EACH NIGHT.
WEDNESDAY NIGHT - FRIDAY...
A DEEP CLOSED LOW IS THEN EXPECTED TO SLIDE INTO OUR AREA AND SLOWLY
MEANDER EASTWARD OVER THE OHIO OR TENNESSEE RIVER VALLEY TO END THE
WORK WEEK. THIS IS EXPECTED TO BRING PERIODS OF SHOWERS AND STORMS
THROUGH THIS STRETCH. TEMPERATURES ARE LIKELY TO STRUGGLE A BIT
UNDER THE HEAVY CLOUD COVER AND PRECIPITATION WITH HIGHS IN THE
UPPER 50S AND LOW 60S.
AVIATION
(12Z TAF ISSUANCE)
ISSUED AT 643 AM EDT SAT OCT 23 2021
IMPACTS: FOG POTENTIAL EARLY THIS MORNING, SHOWERS LATE THIS
AFTERNOON INTO THIS EVENING, THUNDER LATE TONIGHT INTO SUNDAY
MORNING.
DISCUSSION: FOG, DENSE IN SPOTS, HAS FORMED EARLY THIS MORNING AT
BWG AND HNB. AC STREAMING ABOVE HNB HAS HELPED TO KEEP IT IN CHECK
THERE, BUT CLEARER SKIES IN SOUTHERN KENTUCKY HAVE ALLOWED BWG TO GO
DOWN TO THE DECK. HOWEVER, ONCE THIS FOG BURNS OFF, THE BULK OF THE
DAYLIGHT HOURS SHOULD THEN BE VFR IN SOUTHERN INDIANA AND CENTRAL
KENTUCKY.
THIS AFTERNOON AND EVENING A WARM FRONT LIFTING NORTHWARD ACROSS
KENTUCKY WILL BRING SCATTERED SHOWERS TO THE REGION. THUNDER WILL
THEN BE POSSIBLE DURING THE PRE-DAWN HOURS THROUGH MID-MORNING
SUNDAY AT HNB/SDF.LEX AS WE SIT ON THE EDGE OF A STRENGTHENING LLJ
INTERACTING WITH THE NEARBY WARM FRONT.
CONFIDENCE: AVERAGE CONFIDENCE ON TIMING OF FOG DISSIPATION THIS
MORNING. HIGH CONFIDENCE ON FLIGHT RULE CATEGORIES FROM MID-MORNING
TO MID-EVENING, DECREASING LATE TONIGHT.
LMK WATCHES/WARNINGS/ADVISORIES
IN...NONE.
KY...NONE.
SHORT TERM...13
LONG TERM...BJS
AVIATION...13
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page