Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 020800 CCA
AFDJKL

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE JACKSON KY
400 AM EDT THU APR 2 2015

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EDT THU APR 2 2015

DESPITE VERY DRY AIR LINGERING ALOFT OVER THE REGION...A WET AND
STORMY PERIOD IS IN STORE. AT 3 AM RIDGETOPS STILL HAD DEW POINTS
IN THE TEENS AND RELATIVE HUMIDITY IN THE 20S. HOWEVER...GULF OF
MEXICO MOISTURE WAS ON THE WAY IN. SURFACE DEW POINTS WERE NEAR 60
FROM NORTHERN ALABAMA TO WESTERN KENTUCKY...WITH THUNDERSTORMS
ONGOING OVER WESTERN KENTUCKY. THIS MOISTURE WILL QUICKLY ADVECTED
INTO OUR AREA TODAY. AS THE SHORTWAVE TROUGH CAUSING CONVECTION IN
WESTERN KENTUCKY MOVES EAST TODAY...PRECIP WILL DEVELOP. IT WILL
INITIALLY BATTLE LOW LEVEL DOWNSLOPE FLOW AND DRY AIR OVER OUR
AREA...AND ONLY CHANCE CATEGORY POPS HAVE BEEN USED TODAY FOR MOST
LOCATIONS. OUR FAR NW COUNTIES WILL HAVE THE BEST UPPER LEVEL
SUPPORT AND WILL BE OUTSIDE OF THE DOWNSLOPE INFLUENCE...AND
LIKELY POPS HAVE BEEN PLACED THERE.

LOW LEVEL FLOW WILL BECOME MORE SOUTHWESTERLY TONIGHT AND
DOWNSLOPE INFLUENCE WILL BE LOST. A COLD FRONT WILL APPROACH FROM
THE NORTHWEST AND PROVIDE A FOCUS FOR MORE PRECIP. THE HIGHEST
POPS WILL BE IN OUR NORTHWEST COUNTIES...BUT ALL AREAS WILL HAVE A
HIGHER POP. HOWEVER...THE BEST SUPPORT FOR PRECIP WILL BE IN OUR
NORTHERN COUNTIES AS A COLD FRONT APPROACHES FROM THE NORTHWEST.

THE FRONT WILL STALL NEAR THE OHIO RIVER ON FRIDAY...AND THEN GET
A PUSH SOUTHEAST THROUGH THE JKL FORECAST AREA ON FRIDAY NIGHT AS
AN UPPER TROUGH PROMPTS A LOW PRESSURE WAVE TO TRAVEL ALONG THE
FRONT.

AT THIS POINT...THE AXIS OF HEAVIEST PRECIP LOOKS LIKE IT WILL BE
JUST TO OUR NORTH DUE TO THE POSITION OF THE STALLED FRONT. THIS
WILL NEED TO BE WATCHED...SINCE A SLIGHT SOUTHWARD SHIFT WOULD
MEAN HEAVIER PRECIP FOR OUR NORTHERN COUNTIES AND A GREATER THREAT
OF FLOODING. FOR THE TIME BEING...HAVE HELD OFF ON A FLOOD WATCH.

PLENTY OF SHEAR WILL BE AVAILABLE TO SUPPORT ORGANIZED CONVECTION
DURING THIS EVENT...AND SEVERE STORMS CAN NOT BE RULED OUT.
HOWEVER...THE GREATEST INSTABILITY IS EXPECTED TO BE TO OUR WEST
AND SOUTHWEST IN THE AREA OF HIGHER LOW-LEVEL THETA E...AND THE
GREATEST RISK OF SEVERE WEATHER SHOULD BE THERE.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 AM EDT THU APR 2 2015

THE LONG TERM PERIOD STARTS AS ANY REMAINING CONVECTION...RAIN...AND
COLD FRONT PUSH THROUGH OUR AREA. THE MODELS ARE IN GOOD AGREEMENT
WITH THE TIMING OF THE FRONTAL PASSAGE WHICH IS BETWEEN 00Z AND 06Z
SATURDAY FOR THE EASTERN MOST PORTION OF KENTUCKY. COOLER...DRIER
AIR WILL THEN QUICKLY MOVE IN DURING THE DAY ON SATURDAY...WITH THE
EXCEPTION OF SOME UPSLOPE SHOWERS POSSIBLY LASTING INTO THE EARLY
AFTERNOON HOURS. ALL IN ALL...SATURDAY AND SUNDAY WILL BE QUITE
PLEASANT WITH SUNNY SKIES AND TEMPS REACHING THE MID 50S AND MID 60S
RESPECTIVELY.

ON MONDAY...THE UPPER LEVELS TURN MORE WESTERLY TO SOUTHWESTERLY
AHEAD OF A DIGGING TROUGH ACROSS THE WESTERN U.S.. AT THE
SURFACE...SOUTHERLY FLOW WILL PULL IN WARM...MOIST AIR FROM THE
GULF. ADDITIONALLY...BOTH THE GFS AND ECMWF INDICATE A SERIES OF
DISTURBANCES THAT WILL TRACK ACROSS THE REGION...INCREASING THE
CHANCES FOR RAIN AND THUNDERSTORMS AT TIMES FROM MONDAY MORNING
THROUGH THE END OF THE PERIOD. BEST INSTABILITY LOOKS TO BE LATE
MONDAY THROUGH EARLY WEDNESDAY PER LATEST MODEL SOUNDINGS. IN
FACT... CAPE AND LI/S LOOK JUST AS IMPRESSIVE AS IT DOES IN THE
SHORT TERM. HOWEVER...IT IS TOO FAR OUT TO WORK OUT THE DETAILS
GIVEN MODEL DIFFERENCES. SO HAVE WENT WITH THE SUPERBLEND FOR POPS
AND HAVE ALSO INCLUDED THUNDER IN THE WX GRIDS DURING THIS TIME
FRAME.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 127 AM EDT THU APR 2 2015

VFR CONDITIONS PREVAILED AT TAF ISSUANCE...AND WILL PERSIST FOR
THE MOST PART DURING THE PERIOD. CLOUDS IN THE 4-6K FT AGL RANGE
WILL DEVELOP ON THURSDAY MORNING AND PRODUCE CEILINGS AT TIMES
INTO THURSDAY NIGHT. SCATTERED SHOWERS AND POSSIBLY THUNDERSTORMS
WILL ALSO DEVELOP... AND MAY DROP CONDITIONS TO MVFR FOR A TIME.
HOWEVER...LOW CONFIDENCE IN TIMING/LOCATION PRECLUDES USING
ANYTHING MORE THAN VCSH IN TAFS. WINDS WILL PICK UP OUT OF THE S
AND SW DURING THE MORNING...WITH SOME GUSTS AROUND 20KTS IN THE
AFTERNOON.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...HAL
LONG TERM...JVM
AVIATION...HAL



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