939
FXUS63 KLMK 111938
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
338 PM EDT THU SEP 11 2025
KEY MESSAGES
* DRY AND ABNORMALLY WARM WEATHER CONTINUES FOR THE FORESEEABLE
FUTURE.
* POTENTIAL FOR RAPID ONSET DROUGHT AND ENHANCED FIRE WEATHER
CONDITIONS CONTINUES TO INCREASE FOR MID-TO-LATE SEPTEMBER.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 337 PM EDT THU SEP 11 2025
THIS AFTERNOON, THE OHIO VALLEY SITS ON THE SOUTHERN EDGE OF AN
EXPANSIVE AREA OF SFC HIGH PRESSURE CENTERED NEAR THE ONTARIO/QUEBEC
BORDER. DIVERGENT FLOW OUT OF THE HIGH HAS LED TO LIGHT N/NE WINDS
THIS AFTERNOON, WHICH IS HELPING TO PUSH THE AXIS OF GREATER LOW-TO-
MID LEVEL MOISTURE OFF TO THE SOUTHWEST. WE ARE STARTING TO SEE SOME
OF THIS TRANSLATE TO THE SURFACE AS LOW-TO-MID 50S DEWPOINTS ARE
BEGINNING TO CREEP INTO SOUTHERN IN AND NORTHERN KY, WITH UPPER 50S
AND LOWER 60S ACROSS SOUTHERN KY. BOUNDARY LAYER MOISTURE HAS
REMAINED HIGH ENOUGH TO GET A SCATTERED CUMULUS FIELD TO DEVELOP,
WITH A MIX OF SUNSHINE AND THESE SCT CU EXPECTED TO CONTINUE UNTIL
AROUND SUNSET. TEMPERATURES ARE MAINLY IN THE LOW-TO-MID 80S AT THIS
HOUR; WE SHOULD WARM ANOTHER FEW DEGREES BEFORE TOPPING OUT IN THE
MID-TO-UPPER 80S.
TONIGHT, LIGHT AND VARIABLE WINDS AND MOSTLY CLEAR SKIES ARE
EXPECTED. THESE CLEAR AND CALM CONDITIONS, COMBINED WITH LESS NEAR-
SFC MOISTURE, SHOULD ALLOW FOR MORE COOLING TONIGHT COMPARED TO LAST
NIGHT, SO LOWS SHOULD BE A FEW DEGREES COOLER ACROSS THE AREA.
MORNING LOWS ON FRIDAY SHOULD RANGE FROM THE LOW 50S IN RURAL AREAS
AND VALLEYS TO THE LOW 60S IN URBAN AREAS. GIVEN FALLING DEWPOINTS,
FOG FRIDAY MORNING SHOULD BE FAIRLY CONFINED TO AREAS ADJACENT TO
BODIES OF WATER AND SHELTERED VALLEYS, WITH FOG DISSIPATING QUICKLY
AFTER SUNRISE.
TOMORROW, THE SYNOPTIC PATTERN WILL GRADUALLY SHIFT EASTWARD AS
UPPER-LEVEL RIDGING OVER THE PLAINS ENCROACHES ON THE MISSISSIPPI
VALLEY. SFC HIGH PRESSURE WILL BEGIN TO WEAKEN AND SHIFT EAST,
CAUSING LOW-LEVEL WINDS TO VEER TO THE EAST, WITH WIND SPEEDS
REMAINING LESS THAN 10 MPH. THIS FLOW OFF OF THE APPALACHIANS SHOULD
CONTINUE TO KEEP DRY AIR IN PLACE TOMORROW, AND SOUNDINGS WOULD
SUPPORT SOME DRY AIR MIXDOWN. SLIGHTLY INCREASING H85 TEMPS WILL
SUPPORT HIGHS A FEW DEGREES ABOVE PERSISTENCE, WITH HIGHS AGAIN
RANGING FROM THE MID-80S TO AROUND 90. AFTERNOON DEWPOINTS IN THE
LOW-TO-MID 50S SHOULD KEEP THINGS FEELING RELATIVELY COMFORTABLE IN
SPITE OF THE ABOVE-NORMAL TEMPS. LESS DIURNAL CU ARE EXPECTED,
LEADING TO MOSTLY SUNNY SKIES THROUGHOUT THE DAY.
LONG TERM /FRIDAY THROUGH THURSDAY/
ISSUED AT 337 PM EDT THU SEP 11 2025
OVER THE WEEKEND, THE UPPER LEVEL RIDGE WILL CONTINUE TO SPREAD OVER
THE MISSISSIPPI VALLEY AS SHORTWAVE DISTURBANCES BREAK DOWN ITS
WESTERN EDGE OVER THE CENTRAL HIGH PLAINS. AT THE SAME TIME, ANOTHER
TROUGH IS EXPECTED TO DESCEND OVER THE CANADIAN MARITIMES AND
NORTHEAST US. THIS DISTURBANCE WILL HAVE A SFC COLD FRONT ASSOCIATED
WITH IT, BUT THIS FRONT IS NOW EXPECTED TO WASH OUT OVER THE LOWER
GREAT LAKES REGION SATURDAY NIGHT INTO SUNDAY. AS A RESULT, IT IS
NOW VERY LIKELY THAT PRECIPITATION ASSOCIATED WITH THIS SYSTEM WILL
REMAIN TO THE NORTH OF THE REGION, KEEPING DRY WEATHER GOING INTO
EARLY NEXT WEEK. ANY MOISTURE RETURN ASSOCIATED WITH THIS SYSTEM
OVER OUR AREA WILL BE VERY SLIGHT, POSSIBLY RAISING DEWPOINTS BY A
FEW DEGREES. WHILE THIS SHOULD KEEP NIGHTTIME TEMPERATURES MILDER BY
THE SECOND HALF OF THE WEEKEND, TEMPERATURES SHOULD STILL BE ABLE TO
FALL INTO THE UPPER 50S AND LOW-TO-MID 60S. DAYTIME TEMPERATURES
WILL CONTINUE THEIR UPWARD TREND AS THE HEAT DOME IS "SQUEEZED"
EASTWARD: ON SATURDAY, HIGHS SHOULD REACH THE MID-TO-UPPER 80S AND
LOW 90S, WHILE ON SUNDAY, HIGHS SHOULD RANGE FROM THE UPPER 80S TO
THE MID 90S.
EARLY NEXT WEEK, HOT AND DRY CONDITIONS ARE LIKELY TO CONTINUE, AT
LEAST THRU TUESDAY BEFORE FORECAST CONFIDENCE BEGINS TO DECREASE.
WIDESPREAD HIGH TEMPERATURES IN THE LOW-TO-MID 90S ARE EXPECTED AT
THIS TIME, BRINGING THE LONGEST STRETCH OF TEMPERATURES THIS WARM IN
OVER A MONTH. FORTUNATELY, LIMITED MOISTURE RETURN SHOULD KEEP HEAT
INDEX VALUES SUPPRESSED, AND OVERALL, IT SHOULD BE A RELATIVELY
"DRY" HEAT. ON THE OTHER HAND, THIS WILL EXACERBATE DROUGHT
CONDITIONS IN THE AREA, AND WPC DAY 1-7 QPF FORECAST SHOWS LITTLE TO
NO MEASURABLE PRECIP ACROSS THE OHIO AND TN VALLEYS.
BY THE SECOND HALF OF NEXT WEEK, THE UPPER LEVEL PATTERN WILL BECOME
MORE COMPLICATED AS MODEL GUIDANCE DIVERGES ON THE EVOLUTION OF A
CUTOFF LOW JUST OFF THE COAST OF THE CAROLINAS. ONE SOLUTION HAS
THIS LOW RETROGRADING WESTWARD BY THE END OF NEXT WEEK, POTENTIALLY
BRINGING A CHANCE FOR RAIN AS IT APPROACHES THE OHIO VALLEY.
HOWEVER, ANOTHER SOLUTION KEEPS THIS FEATURE OVER THE MID-ATLANTIC
INTO LATE NEXT WEEK, SUPPRESSING RAIN CHANCES.
AVIATION /18Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 132 PM EDT THU SEP 11 2025
SCATTERED CU FIELD WITH CLOUD BASES AROUND 5-6 KFT HAS DEVELOPED
OVER THE AREA AND SHOULD CONTINUE THROUGH THE AFTERNOON AND EARLY
EVENING HOURS, DISSIPATING AROUND SUNSET. WINDS THIS AFTERNOON
SHOULD BE LIGHT, 10 KT OR LESS, OUT OF THE N/NE. TONIGHT, LIGHT AND
VARIABLE WINDS ARE EXPECTED, WITH VFR CONDITIONS EXPECTED TO
CONTINUE AT ALL SITES UNTIL THE IMMEDIATE PRE-DAWN HOURS FRIDAY.
DEPENDING ON HOW MUCH DRY AIR MIXDOWN OCCURS THIS AFTERNOON, NEAR-
SFC MOISTURE MAY BE GREAT ENOUGH FOR MVFR/IFR VSBYS IN FOG,
ESPECIALLY AT BWG. ANY FOG SHOULD QUICKLY DISSIPATE AFTER SUNRISE,
WITH VFR CONDITIONS AND LIGHT E/NE WINDS EXPECTED ON FRIDAY.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...CSG
LONG TERM...CSG
AVIATION...CSG
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