708
FXUS63 KLMK 042325
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
725 PM EDT THU SEP 4 2025
..UPDATED AVIATION DISCUSSION
KEY MESSAGES
* COLD FRONT IS SLOWLY MOVING THROUGH THE REGION TODAY, BRINGING
SOME SHOWERS TO THE REGION THIS AFTERNOON.
* A SECOND COLD FRONT WILL PUSH THROUGH THE REGION LATE FRIDAY AND
SATURDAY. STRONG TO SEVERE STORMS WILL BE POSSIBLE ACROSS THE
REGION AS THIS FEATURE PUSHES THROUGH.
* COOLER AND DRIER AIR WILL RETURN TO THE REGION LATE SATURDAY AND
INTO SUNDAY. PLEASANT WEATHER EXPECTED NEXT WEEK.
SHORT TERM /THROUGH FRIDAY/
ISSUED AT 237 PM EDT THU SEP 4 2025
A MODEST INSTABILITY AXIS HAS DEVELOPED ACROSS SOUTHERN AND
SOUTHEAST KY THIS AFTERNOON, DESPITE FAIRLY HEAVY SKY COVER AND AN
INITIAL ENVIRONMENT "WASHED OUT" BY T-STORM OUTFLOW EARLIER THIS
MORNING. STILL COULD SEE SOME ISOLATED TO WIDELY SCATTERED STRONGER
STORMS DEVELOPING OVER THE MARGINAL RISK AREA THROUGH EVENING,
HOWEVER THE BULK OF THE ACTIVITY LOOKS TO BE SOUTH AND EAST OF THE
REGION. GUSTY WINDS WILL BE THE MAIN THREAT WITH ANY STRONGER STORM,
PERHAPS BRIEFLY SEVERE.
THINGS SHOULD QUIET DOWN OVERNIGHT, WITH A BRIEF LULL IN ACTIVITY
BEFORE THE NEXT SHORTWAVE ROUNDS THE BASE OF THE PARENT TROUGH INTO
FRIDAY. COULD SEE SOME FOG DEVELOPMENT LATER TONIGHT, ESPECIALLY
ACROSS OUR SE CWA WHERE THE FRONTAL BOUNDARY WILL WASH OUT AND
SURFACE MOISTURE WILL BE NOTABLY HIGHER. HAVE ADDED SOME FOG HERE,
AND WILL LIKELY MESSAGE WATER BODIES AND AREAS THAT SAW GOOD AMOUNTS
OF RAINFALL EARLIER TODAY AS WELL.
WE'LL SEE A MUCH WARMER AND INCREASINGLY MOIST AIRMASS SET UP OVER
OUR CWA THROUGH THE DAY AS A WARM FRONT LIFTS NORTH OF OUR AREA
AHEAD OF AN APPROACHING COLD FRONT. A FEW WIND GUSTS IN THE 20 TO 30
MPH RANGE ARE ALSO LIKELY GIVEN THE DEEPENING SW SURFACE FLOW.
04/00Z HREF SHOWS LIKELY PROBABILITIES OF AT LEAST 1500 TO 2500 J/KG
OF ML CAPE DEVELOPING ALONG AND SOUTH OF THE OHIO RIVER TOMORROW.
DEEP LAYER SHEAR WILL BE SUFFICIENT FOR STORM ORGANIZATION, MOSTLY
NOTABLY WITH STRONG DEEP LAYER SPEED SHEAR. OVERALL THE PROFILE IS
PRETTY UNIDIRECTIONAL WHICH MAY SUPPORT A FEW SPLITTING SUPERCELL
STORM MODES BEFORE QUICKLY GROWING UPSCALE AND BOWING OUT THANKS TO
FAIRLY DRY LOW LEVEL SOUNDINGS (INVERTED V) PROMOTING HIGH DCAPE
VALUES. IT IS WORTH NOTING THAT 0-3 KM SRH VALUES LOOK FAIRLY
IMPRESSIVE INTO THE EVENING HOURS THANKS TO THAT STRONGER SPEED
SHEAR, HOWEVER 0-1 KM SRH VALUES DROP OFF SIGNIFICANTLY GOING INTO
THE EVENING WHICH IS THANKS TO THE MORE UNIDIRECTIONAL LOW LEVEL
PROFILE BY THAT TIME. THIS IS PRETTY GOOD REASONING FOR WHY THE 2%
TOR THREAT HOLDS, BUT ISN'T HIGHER THANKS TO THE LOWEST 1 TO 2 KM
NOT BEING AS FAVORABLE FOR TORNADIC POTENTIAL. THIS FACTOR COMBINED
WITH ANY SUPERCELL STORM MODES LIKELY BEING SHORT-LIVED BEFORE
GUSTING/BOWING OUT SHOULD KEEP THE TORNADO THREAT LOW, BUT NOT
COMPLETELY ZERO.
LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/
ISSUED AT 237 PM EDT THU SEP 4 2025
FRIDAY NIGHT THROUGH SATURDAY MORNING...
BROAD UPPER TROUGHING CONTINUES TO ENVELOP MUCH OF THE EASTERN CONUS
HEADING INTO THE WEEKEND, WITH A PARTICULARLY NOTABLE SHORTWAVE
EMBEDDED WITHIN THAT PARENT TROUGH SWINGING THROUGH FRIDAY NIGHT.
WE'LL CONTINUE TO SEE RIGHT ENTRANCE REGION MID TO UPPER LEVEL
JETTING OVER OUR REGION AS THIS OCCURS, WITH SOME RESPONSE IN THE
LOW LEVEL JET. THIS SETUP WILL PROVIDE ENOUGH DEEP LAYER SHEAR AND
FORCING TO CONTINUE SCATTERED TO NUMEROUS INCREASINGLY ELEVATED
THUNDERSTORMS ACROSS OUR AREA. AT THE SURFACE, A COOL FRONT WILL BE
PUSHING SE THROUGH THE AREA, EFFECTIVELY ENDING THE SURFACE-
BASED/SEVERE WEATHER THREAT, HOWEVER FORECAST SOUNDINGS SUGGEST
THERE SHOULD STILL BE PLENTY OF ELEVATED INSTABILITY TO WORK WITH.
SO, THE SEVERE THREAT SHOULD DIMINISH THE DEEPER INTO FRIDAY NIGHT
WE GET, BUT CAN'T RULE OUT SOME HAILERS, AND PERHAPS SOME LOCALLY
HEAVY RAINFALL. IT IS A BIT CONCERNING THAT STORMS LOOK TO TRAIN W
TO E ACROSS THE AREA BENEATH THAT STRONG UPPER LEVEL JETTING, SO
COULD SEE SOME LOCALIZED HYDRO ISSUES, ESPECIALLY FOR A FEW AREAS
THAT HAVE ALREADY SEEN SOME HEAVIER RAINFALL TOTALS WITH THESE
EARLIER WAVES. SOMETHING TO WATCH FOR POTENTIAL DAY 2 ERO OUTLOOKS.
THE UPPER TROUGH AXIS SHOULD SWING THROUGH BY SATURDAY MORNING, WITH
THE ENHANCED LOW LEVEL JETTING LETTING GO ACROSS THE AREA. THIS
SHOULD GRADUALLY END SHOWER AND STORM COVERAGE THROUGH THE MORNING,
WITH A DRY FORECAST GOING INTO THE REST OF SATURDAY. FROM THERE, THE
FORECAST LOOKS TO DRY OUT, AND THE STORY TRANSITIONS TO THE COOL
TEMPERATURES.
THE REST OF SATURDAY THROUGH THURSDAY...
WE REMAIN UNDER BROAD TROUGHING THROUGH THE WEEKEND, HOWEVER STRONG
CANADIAN HIGH PRESSURE LOOKS TO BUILD IN BEHIND THE DEPARTING COLD
FRONT. THIS WILL KEEP US COOL AND DRY THROUGH THE WEEKEND AND INTO
NEXT WEEK. SATURDAY HIGHS ONLY LOOK TO GET INTO THE UPPER 60S TO
AROUND 70 FOR HIGHS, WITH SUNDAY RECOVERING BACK TO THE LOW AND MID
70S. MORNINGS WILL BE CHILLY WITH 45 TO 50 EXPECTED FOR MOST ON
SUNDAY MORNING, AND LOWS WELL INTO THE 40S FOR MONDAY MORNING. IN
OTHER WORDS, SOME LOW 40S ARE EXPECTED FOR THE COOLEST SPOTS! THESE
VALUES COULD FLIRT WITH SOME RECORD LOW FOR SUNDAY/MONDAY MORNINGS.
TEMPERATURES MODERATE THROUGH THE NEW WORK WEEK WITH HIGHS BACK IN
THE LOW TO MID 80S BY WED/THUR. OVERNIGHT LOWS TREND A LITTLE MILDER
EACH NIGHT, ENDING UP BACK IN THE 50S BY MID WEEK.
AVIATION /00Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 724 PM EDT THU SEP 4 2025
LIGHT NW FLOW AND VFR FLIGHT CATS ARE ACROSS ALL TERMINALS THIS
EVENING. WE EXPECT A QUIET OVERNIGHT WITH LIGHT AND VARIABLE WINDS
AND MOSTLY CLEAR SKYCOVER. BY TOMORROW, A STALLED BOUNDARY WILL LIFT
NORTHWARD THROUGH THE REGION AGAIN, OPENING THE DOOR AGAIN FOR WARM
AIR AND GUSTY SOUTHWESTERLY WINDS PICKING UP BY LATE MORNING. WE
REMAIN DRY FOR MOST OF THE PERIOD, BUT A SECOND COLD FRONT WILL
APPROACH THE REGION LATER IN THE DAY, WHICH WILL BRING SHOWER AND
STORMS TO THE TERMINALS. HIGHLIGHTED PROB30 GROUPS FOR -TSRA, AS
STORMS SHOULD BE MOSTLY SCATTERED IN THE LATE AFTERNOON BEFORE SHRA
INCREASES IN COVERAGE BEYOND THE 24-HOUR PERIOD.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...BJS
LONG TERM...BJS
AVIATION...CJP
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