137
FXUS63 KLMK 130447
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1247 AM EDT MON JUL 13 2020
FORECAST UPDATE
ISSUED AT 815 PM EDT SUN JUL 12 2020
MOST OF THE STORM ACTIVITY HAS PASSED SOUTH AND EAST OF THE REGION
THIS HOUR...THOUGH HAVE A FEW MORE POP UP STORMS OUT THERE, MAINLY
SOUTH AND EAST OF A HARTFORD TO SHELBYVILLE LINE IN KY. A NORTHERLY
FLOW SHOULD CONTINUE TO BRING IN DRIER AIR. CANNOT RULE OUT SOME
PATCHY FOG AS IN PREVIOUS FORECAST DISCUSSION. MAIN REASON FOR THIS
UPDATE IS TO REMOVE THE AFTERNOON WORDING. REST OF THE FORECAST
PRETTY MUCH ON TRACK.
SHORT TERM
(THIS EVENING THROUGH MONDAY)
ISSUED AT 253 PM EDT SUN JUL 12 2020
..STRONG TO SEVERE STORMS POSSIBLE THIS AFTERNOON
ISOLATED TO SCATTERED SHOWERS AND STORMS HAVE DEVELOPED THIS
AFTERNOON AHEAD OF A WEAK FRONTAL BOUNDARY. UNLIKE THE LONE
ANTICYCLONIC SUPERCELL THAT FORMED EARLIER THIS MORNING, STORMS
WITHIN THE PAST 30-60 MINUTES HAVE REMAINED RELATIVELY TAME AND
UNDER SEVERE THRESHOLDS. WE'RE STARTING TO SEE SOME HIGHER
THETA-E/TD AIR ADVECT IN FROM THE SOUTHWEST, WHERE DEWPOINTS IN
SOUTHWESTERN KY ARE CURRENTLY IN THE MID 70S. SKIES ARE ALSO
RELATIVELY CLEAR ACROSS THE SOUTHERN HALF OF KENTUCKY, SO LAPSE
RATES SHOULD STEEPEN AS WE GET INTO THE LATE AFTERNOON. THE
COMBINATION OF STEEPENING LAPSE RATES AND INCREASING LOW LEVEL
MOISTURE SHOULD SET UP FAVORABLE INSTABILITY PROFILES ACROSS THE
SOUTHERN HALF OF KENTUCKY. EFFECTIVE BULK SHEAR WILL GENERALLY
RANGE FROM 30-40KTS IN THIS UNSTABLE AIR MASS AND LIKELY RESULT IN
ORGANIZED CONVECTION. THUS, WHILE STORMS MAY NOT BE DOING MUCH AT
THIS PRESENT TIME, EXPECT ACTIVITY TO STRENGTHEN AS IT PUSHES
SOUTHWARD OVER THE NEXT COUPLE OF HOURS. THINK THE MAIN SEVERE
THREAT WINDOW WILL RUN FROM 20Z - 01Z. DAMAGING WIND GUSTS AND
HAIL WILL BE THE MAIN SEVERE THREATS.
ACTIVITY SHOULD GRADUALLY WANE IN COVERAGE AND INTENSITY TOWARD
SUNSET, WITH MOST ACTIVITY PUSHING SOUTH OF OUR BORDER BY 02Z-04Z.
SKIES SHOULD CLEAR OUT OVERNIGHT AND WINDS REMAIN LIGHT OUT OF THE
NORTH. THERE IS A POTENTIAL FOG SIGNAL FOR PARTS OF CENTRAL/EASTERN
KY OVERNIGHT IF WINDS CAN TURN CALM, PARTICULARLY IN AREAS THAT SEE
RAINFALL TODAY.
OTHERWISE, TOMORROW SHOULD BE MOSTLY SUNNY AND DRY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTH. WHILE AIR TEMPERATURES WILL
STILL BE WARM BEHIND THIS FRONT (MID TO UPPER 80S), DEWPOINTS WILL
BE A TOUCH LOWER COMPARED TO PREVIOUS DAYS, SO IT WON'T FEEL QUITE
AS MUGGY AS WHAT IT HAS BEEN.
LONG TERM
(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 255 PM EDT SUN JUL 12 2020
SURFACE HIGH PRESSURE WILL GIVE US A COUPLE OF DRY YET VERY WARM
DAYS ACROSS THE REGION TUESDAY AND WEDNESDAY. DEW POINTS TUESDAY
WILL BE THE LOWEST OF THE LONG TERM IN THE MID 60S WITH HIGHS NEAR
90 AND THE UPPER 80S. WEDNESDAY WILL SEE AN INCREASE IN MOISTURE AND
TEMPERATURES AS THE UPPER-LEVEL RIDGE TO OUR SOUTH AND WEST BEGINS
TO BUILD. DEW POINTS CLIMB INTO THE UPPER 60S TO NEAR 70 AND HIGHS
90 TO 95 WITH HEAT INDICES NEAR 100.
WEAK BOUNDARY SLIDE IN ACROSS THE OHIO VALLEY WEDNESDAY NIGHT INTO
THURSDAY THEN LOOKS TO STALL NEAR THE OHIO RIVER THURSDAY INTO
SATURDAY. CONFIDENCE IS LOW ON PLACEMENT OF THIS BOUNDARY BUT IT'S
PROXIMITY ACROSS THE REGION, PLENTY OF LOW LEVEL MOISTURE AND
TEMPERATURES INTO THE LOW TO MID 90S, CONVECTIVE CHANCES REMAIN
THROUGH THE END OF THE WEEK AND INTO THE WEEKEND. WITH POTENTIAL
AFTERNOON HIGH TEMPERATURES IN THE LOW TO MID 90S EACH DAY AND DEW
POINTS IN THE 70, HEAT INDEX VALUES COULD REACH NEAR OR JUST ABOVE
100 DEGREES.
AVIATION
(06Z TAF ISSUANCE)
ISSUED AT 1245 AM EDT MON JUL 13 2020
MAIN CHALLENGE IN THIS TAF SET WILL BE OVERNIGHT FOG POTENTIAL,
ESPECIALLY AT BWG WHERE DEWPOINTS REMAIN HIGH AND THERE WAS SOME
RAIN DURING THE DAY. SKIES ARE MAINLY CLEAR AND WINDS HAVE
GONE NEARLY CALM, BUT WEIGHING AGAINST FOG IS SOME MODEST DRY AIR
ADVECTION THAT HAS ALREADY OCCURRED ON LIGHT NORTHERLY WINDS.
CAN'T RULE OUT LOWER VIS AT ANY OF THE TERMINALS, BUT WILL GO FOR A
COUPLE HRS OF MVFR VIS EITHER SIDE OF DAYBREAK AT BWG, LEX, AND HNB.
HEAT ISLAND INFLUENCES SHOULD KEEP SDF FROM DROPPING AT ALL.
OTHER THAN THE BRIEFLY LOWER VIS, EXPECT VFR CONDITIONS AND LIGHT
NORTH WINDS THROUGH THE PERIOD.
LMK WATCHES/WARNINGS/ADVISORIES
IN...NONE.
KY...NONE.
UPDATE...RJS
SHORT TERM...DM
LONG TERM...BTN
AVIATION...RAS
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