Area Forecast Discussion
Issued by NWS Jackson, KY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KJKL 051217
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
817 AM EDT WED AUG 5 2015

.UPDATE...
ISSUED AT 816 AM EDT WED AUG 5 2015

CURRENT CONDITIONS ACROSS THE AREA THIS MORNING FEATURE SOME AREAS
OF FOG ACROSS THE AREA. THIS WILL LIKELY CONTINUE A COUPLE MORE
HOURS BEFORE DISSIPATING. SOME SLIGHT TO CHANCE POPS REMAIN IN THE
FORECAST THIS MORNING BUT WITH A FEW RETURNS BEGINNING TO DEVELOP
IN CENTRAL KY SO WILL KEEP THE CURRENT FORECAST AS IS. SO WILL
ANTICIPATE INCREASED SHOWERS AND THUNDERSTORMS AS THE AFTERNOON
APPROACHES WITH THE HEAVY RAINFALL THREAT ARRIVING LATE THIS
AFTERNOON INTO THE EVENING. HAVE UPDATED THE GRIDS WITH THE LATEST
OBS AND SENT THEM TO NDFD.

&&

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 421 AM EDT WED AUG 5 2015

CURRENT CONDITIONS ACROSS THE AREA FEATURE A QUASI-STATIONARY
BOUNDARY ACROSS THE OH VALLEY AND INTO THE MID MS VALLEY. ALONG
THIS BOUNDARY CURRENTLY...PLENTY OF CLOUD COVER CONTINUES TO MOVE
THROUGH KY ASSOCIATED WITH DECAYING UPSTREAM CONVECTION. ACROSS
THE AREA...PLENTY OF MOISTURE REMAINS IN PLACE WITH DEW POINTS
ACROSS THE AREA IN THE MID 60S. SUCH A MOIST AND UNSTABLE
ATMOSPHERE WILL BE CONDUCIVE FOR EARLY CONVECTION THIS MORNING AND
ESPECIALLY HEADING INTO THE DAY. WILL DEAL WITH SOME FOG IN THE
DEEPER RIVER VALLEYS THIS MORNING BEFORE THIS BURNS OFF JUST AFTER
14Z.

ALOFT...THE PATTERN REMAINS WITH A TROUGH OVER THE EASTERN CONUS
WITH THE BASE OF THE TROUGH ROUNDING OUT JUST ALONG THE TN VALLEY.
HEADING INTO THE DAY A STRONG WAVE HAS TRAVERSED THE RIDGE OVER
THE FRONT RANGE AND NOW STREAKS EAST INTO THE CENTRAL PLAINS AND
THEN WESTERN KY. SOME UPPER LEVEL ENERGY AHEAD OF THIS FEATURE
ALREADY NOW INTO WESTERN KY WILL BE ENOUGH FOR SOME CONVECTION TO
DEVELOP INTO EASTERN KY BY 15Z. THE BETTER FORCING AND UPPER LEVEL
SUPPORT ARRIVES LATER TODAY AND INTO THE AFTERNOON. MODELS HAVE
BEEN OFF ON THE TIMING OF THIS FEATURE BUT CURRENT CONDITIONS
UPSTREAM IN MO AND KS WOULD SUGGEST AN EARLY START TO THE ACTIVITY
TODAY. MODEL SOUNDINGS HEADING INTO THE AFTERNOON...WHILE A TAD
OVER DONE...SUGGEST PLENTY OF INSTABILITY IN PLACE WITH PWATS IN
THE 1.6 TO 2.0 RANGE. ONCE AGAIN THIS WILL POSE A THREAT OF HEAVY
RAINFALL AND TRAINING STORMS. A RATHER HIGH FREEZING LEVEL AND
LACK OF WINDS ALOFT WILL MAKE FOR MOSTLY SUB SEVERE STORMS THIS
AFTERNOON AND EVENING...THOUGH A FEW STORMS MAY BE STRONG. THE
BULK OF THESE INGREDIENTS ARRIVE THIS EVENING INTO TONIGHT AS THE
AFOREMENTIONED STRONG WAVE ARRIVES IN EAST KY.

CONCERNING TONIGHT AND INTO THURSDAY...MODEL PROFILES FOR THIS
TIME PERIOD INDICATE QUITE A STEEP WARM LAYER...NEAR 2 INCH
PWATS...AND CAPE PROFILES EQUALLY DISTRIBUTED ALONG THE COLUMN
ALLOWING FOR EFFICIENT RAINFALL PRODUCTION. WHILE STORM MOTION
WILL BE A BIT QUICKER AT 10 KNOTS OR MORE ALLOWING LESS RESIDENCE
TIME...THE PREVIOUSLY MENTIONED INGREDIENTS WILL BE ENOUGH TO SET
THE STAGE FOR HEAVY RAINFALL WITH FLASH FLOODING POSSIBLE.
THEREFORE...HAVE EXTENDED THE FLASH FLOOD WATCH TO INCLUDE THE
SOUTHERN COUNTIES AND THUS...ALL OF EASTERN KENTUCKY. HAVE ALSO
INCLUDED SOME HEAVY RAINFALL MENTION IN THE WEATHER GRIDS TO
ACCOUNT FOR THIS. FOR THURSDAY...AS THE UPPER TROUGH DEEPENS AND
THE TROUGH AXIS MOVES THROUGH KENTUCKY WITH THE BETTER SUPPORT
ALOFT AND INSTABILITY FROM THE DAYS HEATING...THOUGH LESS...WILL
ALLOW HEAVY RAINFALL PRODUCING STORMS TO CONTINUE INTO THURSDAY
AFTERNOON.

ONE FORECAST ISSUE CONCERNING CONVECTION LATER TONIGHT AND INTO
THURSDAY...MOST LIKELY THERE WILL BE SOME ORGANIZATION WITH STORMS
DEVELOPING ALONG THE BOUNDARY AND UPPER LEVEL SUPPORT IN PLACE...SO
THIS WOULD MAKE PRECIP RATHER INTERMITTENT AT TIMES THROUGH THE
PERIOD. IF ANY OF THIS DEVELOPS DURING THIS TIME OR A COLD POOL
DEVELOPS...THERE MAY BECOME A WIND THREAT BUT THIS IS UNLIKELY AT
THIS TIME.

.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 527 AM EDT WED AUG 5 2015

THE MODELS REMAIN IN DECENT AGREEMENT WITH A MODESTLY AMPLIFIED
LONG WAVE PATTERN THROUGH THE WEEKEND...BEFORE THE PATTERN
SHARPENS UP MORE BY EARLY NEXT WEEK. THE MAIN FEATURES OF INTEREST
WILL BE A PERSISTENT UPPER LEVEL RIDGE THAT WILL MOVE FROM THE
DESERT SOUTHWEST TO THE ARKLATEX REGION...BEFORE GRADUALLY
RETREATING BACK TO THE WEST ONCE AGAIN AND AMPLIFYING ACROSS THE
PLAINS. MEANWHILE...TROUGHING IN THE EASTERN CONUS WILL GRADUALLY
MOVE OFF THE COAST...BEFORE EVENTUALLY BEING REPLACED WITH A
DEEPER TROUGH AS A SHORT WAVE INTENSIFIES AS IT HEADS ACROSS THE
GREAT LAKES/OHIO VALLEY REGIONS BY EARLY NEXT WEEK. DETAILS ON HOW
ALL OF THIS PLAYS OUT STILL REMAIN UNCERTAIN...SO HAVE CONTINUED
TO STICK CLOSE TO THE BLENDED GUIDANCE APPROACH.

A TROUGH AXIS WILL BE SHIFTING THROUGH OUR AREA THURSDAY NIGHT
INTO FRIDAY...WITH SHOWERS AND THUNDERSTORMS ON THE
DECREASE...ESPECIALLY AFTER MIDNIGHT. GENERALLY DRY WEATHER WILL
RESUME ACROSS THE AREA FOR THE WEEKEND...AS THE UPPER LEVEL RIDGE
BUILDS IN FROM THE SOUTHWEST. UNSETTLED WEATHER WILL THEN RETURN
FOR EARLY NEXT WEEK...AS THE DEEPER TROUGHING SWINGS THROUGH THE
OHIO VALLEY. TEMPERATURES WILL GENERALLY AVERAGE NEAR NORMAL
THROUGH THE PERIOD...WITH LOWER HUMIDITY ON THE HORIZON BY THE
MIDDLE OF NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 816 AM EDT WED AUG 5 2015

WITH RECENT RAINFALL AND LIGHT WINDS...PATCHY FOG HAS DEVELOPED
ACROSS THE AREA. EXPECT FOG TO DISSIPATE BY 14Z THIS MORNING AS
THE INVERSION BEGINS TO BREAK. HEADING INTO THIS
AFTERNOON...SHOWERS AND THUNDERSTORMS WILL BECOME MORE NUMEROUS
AND HAVE ADDED VCTS TO THE TAF SITES AFTER 18Z. INCREASED COVERAGE
WILL BEGIN ACROSS THE AREA AFTER 00Z TONIGHT WITH THE BETTER LIFT
MOVING IN. HAVE ADDED A TEMPO GROUP TO THE TAF SITES BY THE 06Z
PERIOD FOR BELOW FILED MINS DUE TO THUNDERSTORMS. COVERAGE DURING
THIS TIME WILL BE QUITE EXTENSIVE. EXPECT MAINLY LIGHT WINDS
THROUGH THE TAF PERIOD OUTSIDE OF THUNDERSTORMS.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 5 PM EDT THIS AFTERNOON THROUGH LATE
THURSDAY NIGHT FOR KYZ044-050>052-058>060-068-069-079-080-
083>088-104-106>120.

&&

$$

UPDATE...SHALLENBERGER
SHORT TERM...SHALLENBERGER
LONG TERM...GEOGERIAN
AVIATION...SHALLENBERGER


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.