Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 021926
AFDLMK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
326 PM EDT SUN AUG 2 2015

.SHORT TERM (NOW THROUGH MONDAY NIGHT)...
ISSUED AT 300 PM EDT SUN AUG 2 2015

NW FLOW ALOFT WILL PERSIST THROUGH THE SHORT TERM...MEANWHILE
SURFACE HIGH PRESSURE WILL LOSE INFLUENCE OVER THE AREA TONIGHT. A
FRONTAL BOUNDARY WILL THEN APPROACH AND STALL OVER THE REGION MONDAY
AFTERNOON THROUGH MONDAY NIGHT...BRINGING ISOLATED TO WIDELY
SCATTERED CHANCES FOR SHOWERS STORMS.

BEFORE WE DEAL WITH PRECIPITATION CHANCES...WE`LL ENJOY ONE MORE
PLEASANT AND DRY AFTERNOON/EVENING WITH TEMPS IN THE UPPER 80S AND
LOW 90S. DEW POINTS HAVE ONCE AGAIN MIXED INTO THE 50S AND 60S
MAKING FOR PLEASANT CONDITIONS. WE`LL SEE AN INCREASE IN UPPER
CLOUDS FROM THE NW THROUGH THE OVERNIGHT WITH LOWS MOSTLY IN THE MID
60S. A FEW SE COOL SPOTS MAY DROP NEAR 60 ONCE AGAIN...MEANWHILE THE
WARMEST SPOTS MAY END UP IN THE UPPER 60S TO NEAR 70. CAN`T RULE OUT
A FEW DIMINISHING SHOWERS SINKING ACROSS OUR SOUTHERN IN AND
NORTHERN KY COUNTIES TOWARD DAWN...HOWEVER CONFIDENCE IN CONVECTIVE
DEVELOPMENT/EVOLUTION UPSTREAM IS LOW AND WILL LEAVE ANY MENTION OUT
FOR NOW...ESPECIALLY GIVEN OUR DRIER AIRMASS IN PLACE.

A SHORTWAVE PASSES THROUGH THE GREAT LAKES EMBEDDED IN THE NW FLOW
ALOFT TONIGHT THROUGH MONDAY. THIS WILL DRAG A TRAILING COLD FRONT
INTO OUR REGION ON MONDAY WITH MOISTURE POOLING AHEAD OF THIS
FEATURE. CONVERGENCE ALONG THIS FRONT COMBINED WITH MODERATE
INSTABILTY SHOULD ALLOW FOR ISOLATED TO WIDELY SCATTERED CONVECTIVE
DEVELOPMENT BY AFTERNOON. GIVEN 0-6 KM BULK SHEAR VALUES IN THE 20-
30 KNOT RANGE...NOT EXPECTING MUCH IN THE WAY OF
ORGANIZATION...HOWEVER A FEW OF THE STRONGER STORMS WILL BE CAPABLE
OF STRONG GUSTY WINDS AND BRIEF HEAVY RAINFALL. BEST OVERLAP OF
INSTABILITY/MARGINAL SHEAR WILL BE ACROSS SE INDIANA AND NORTH
CENTRAL KY WHERE THE STRONGEST/MOST ORGANIZED STORMS WILL BE
POSSIBLE. MONDAY SHOULD BE ABLE TO WARM NICELY AHEAD OF AFTERNOON
DEVELOPMENT SO WILL CALL FOR UPPER 80S/LOW 90S FOR HIGHS.

WILL LEAVE ISOLATED MENTION OF SHOWERS/STORMS IN THE FORECAST MONDAY
NIGHT AS THE FRONTAL BOUNDARY STALLS OVER THE REGION...NEARLY
PARALLEL TO THE UPPER FLOW. LOOK FOR MILDER LOWS WITH TEMPS ONLY
BOTTOMING OUT IN THE 65-70 RANGE.

.LONG TERM (TUESDAY THROUGH SUNDAY)...
ISSUED AT 320 PM EDT SUN AUG 2 2015

LONG TERM MODELS CONTINUE TO SHOW FAIRLY GOOD CONSISTENCY IN THEIR
FORECAST THROUGHOUT THE UPCOMING EXTENDED FORECAST PERIOD.  A LOW
AMPLITUDE RIDGE WEST/TROUGH EAST PATTERN IS VERY LIKELY IN THE
BEGINNING OF THE PERIOD WITH A THE FIRST IN A SERIES OF MID-LEVEL
WAVES SWINGING THROUGH THE REGION LATE TUESDAY INTO WEDNESDAY.
SEVERAL ADDITIONAL WAVES WILL SWING THROUGH THE REGION DURING THE
LATTER HALF OF THE WEEK WITH A RETURN TO DRIER WEATHER EXPECTED BY
THE WEEKEND.

IN TERMS OF SENSIBLE WEATHER, A COLD FRONT WILL DROP INTO THE REGION
EARLY IN THE PERIOD AND THEN STALL OUT.  AS IT STALLS OUT, THE
AFOREMENTIONED UPPER LEVEL WAVES WILL MOVE FROM WEST TO EAST ALONG
THE FRONT BRINGING MULTIPLE ROUNDS OF CONVECTION.  THE LATEST DATA
CONTINUE TO SUGGEST THAT THE HIGHEST RAIN CHANCES WILL BE WEDNESDAY
AND THURSDAY AS THE UPPER LEVEL SYSTEM PULLS THROUGH THE REGION.
PERCEPTIBLE WATER VALUES WILL CREEP BACK UP TOWARD 2 INCHES, SO
CONVECTION THAT DEVELOPS WED/THU WILL HAVE THE POTENTIAL TO PRODUCE
HEAVY RAINFALL.  OVERALL THREAT OF SEVERE WEATHER AT THIS POINT
STILL LOOKS MARGINAL GIVEN THE UNCERTAIN EVOLUTION OF THE MESOSCALE
PATTERN.  IT DOES LOOK FAIRLY LIKELY THAT STORMS MAY TRAIN ACROSS
THE REGION YIELDING SOME HEAVY RAINFALL TOTALS.  QPF AMOUNTS FROM
THE MODELS CONTINUE TO BE A BIT DIVERGENT IN PLACEMENT AND IN
QUANTITY.  CURRENT THINKING IS THAT 2 TO 3 INCHES OF RAINFALL FROM
MID-LATE WEEK STILL LOOKS LIKELY.

TEMPERATURES WILL BE THE WARMEST ON TUESDAY WITH HIGHS IN THE MID-
UPPER 80S IN THE NORTH WITH UPPER 80S TO LOWER 90S ACROSS THE SOUTH.
COOLER TEMPERATURES ARE EXPECTED WEDNESDAY AND THURSDAY DUE TO
CLOUDINESS AND EXPECTED SHOWERS/STORMS.  HIGHS IN THE LOW-MID 80S
LOOK GOOD FROM THE BLENDED GUIDANCE.  MUCH COOLER WEATHER LOOKS TO
BE IN STORE AS WE HEAD INTO THE WEEKEND.  FRIDAY/SATURDAY HIGHS LOOK
TO TOP OUT IN THE UPPER 70S TO LOWER 80S WITH A SLIGHT WARM UP
EXPECTED TO COMMENCE BY SUNDAY.  OVERNIGHT LOWS WILL START OFF IN
THE UPPER 60S TO THE LOWER 70S AND THEN COOL DOWN TOWARD THE LOWER
60S BY THE END OF THE PERIOD.

&&

.AVIATION (18Z TAF UPDATE)...
ISSUED AT 113 PM EDT SUN AUG 2 2015

VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THIS FORECAST PERIOD,
ALTHOUGH SURFACE HIGH PRESSURE WILL BEGIN TO LOSE HOLD ON THE
REGION. WE`LL SEE LIGHT SSW WINDS THIS AFTERNOON ALONG WITH A FEW
UPPER LEVEL CLOUDS STREAMING OVERHEAD. T-STORMS WILL GET GOING
UPSTREAM OF SDF/LEX THROUGH THE OVERNIGHT HOWEVER ARE EXPECTED TO
DIMINISH BEFORE REACHING SO WILL LEAVE DRY FOR NOW. WILL INCLUDE A
SCATTERED LAYER OF LOW/MID CLOUDS NEAR SUNRISE. WSW WINDS WILL THEN
INCREASE INTO THE DAY ON MONDAY WITH CONTINUED SCATTERED CLOUDS. A
FEW THUNDERSTORMS MAY IMPACT THE AREA BY LATER MONDAY AFTERNOON.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&

$$

SHORT TERM........BJS
LONG TERM.........MJ
AVIATION..........BJS


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