Area Forecast Discussion
Issued by NWS Jackson, KY

Home | Current Version | Previous Version | Graphics & Text | 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 041446
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
1046 AM EDT TUE AUG 4 2015

.UPDATE...
ISSUED AT 1046 AM EDT TUE AUG 4 2015

BOUNDARY FROM LAST NIGHTS CONVECTION LIES ACROSS THE SOUTHWEST
PART OF THE FORECAST AREA AND WILL SERVE TO FOCUS CONVECTION THIS
AFTERNOON. NDFD AND ASSOCIATED PRODUCTS HAVE BEEN UPDATED TO
ACCOUNT FOR LATEST OBSERVATIONAL TRENDS. DELAYED ANY PRECIPITATION
CHANCES UNTIL THIS AFTERNOON.

UPDATE ISSUED AT 755 AM EDT TUE AUG 4 2015

CURRENT CONDITIONS ACROSS THE AREA THIS MORNING FEATURE SOME
VALLEY FOG ACROSS EASTERN KENTUCKY. DID KEEP IN SOME FOG IN THE
ZONES FOR THIS. ALSO REMOVED SOME THUNDER FROM THE MORNING
WORDING AS ANY CONVECTION SHOULD HOLD OFF TILL AFTER 16Z. THIS IS
CONFIRMED BY THE HIGH RES MODELS INCLUDING THE HRRR. MODEL
SOUNDINGS SHOWING INCREASED INSTABILITY AND WEAKENING CAP SHORTLY
AFTER 15Z AND THE BOUNDARY IN PLACE OVER THE SOUTH WILL ALLOW
SHOWER AND THUNDERSTORM ACTIVITY TO BEGIN TO DEVELOP BY THE
AFTERNOON.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 430 AM EDT TUE AUG 4 2015

CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURES SOME WANING
CONVECTION AHEAD OF A COLD FRONT. WILL KEEP SOME SLIGHT CHANCE
POPS THROUGH DAWN TO COVER THIS ACTIVITY BUT OVERALL...THE
WEAKENED FORCING AND LACK OF INSTABILITY WILL BRING THIS ACTIVITY
TO AN END. LOCATIONS ACROSS THE AREA RECEIVED SOME HEAVY RAINFALL
OVERNIGHT AND A SATURATED SURFACE COUPLED WITH LIGHT WINDS...WILL
SEE SOME FOG DEVELOPMENT THROUGH DAWN.

HEADING INTO THE DAY...THE FRONT THAT PASSED THROUGH OVERNIGHT
WILL STALL OUT OVER THE KY AND TN BORDER AREA. THE UPPER LEVEL
FLOW SETS UP IN A RIDGE OVER THE WEST AND TROUGH OVER THE EAST
WITH NUMEROUS WAVES TRAVELING OVER THE RIDGE AND INTO THE CENTRAL
PLAINS...EVENTUALLY TRACKING INTO KY. THE NEXT UPPER LEVEL WAVE
WILL TRACK INTO THE SOUTHERN KY BY LATE TUESDAY. PLENTY OF SURFACE
INSTABILITY ALONG WITH THE WAVE AND A BOUNDARY IN PLACE WILL ALLOW
AFTERNOON AND EVENING CONVECTION OVER SOUTHERN KENTUCKY WITH A
SLIGHT CHANCE TO THE NORTH. THIS ACTIVITY WILL TAKE MORE OF A
DIURNAL TREND TO IT WITH CONVECTION WANING SHORTLY AFTER SUNSET.

SURFACE HIGH PRESSURE PASSING BY TO THE NORTH TUESDAY NIGHT WILL
PROVIDE SOME SUBSIDENCE AND LIGHT WINDS ONCE AGAIN COMBINED WITH
SOME DEW POINTS STILL IN THE MID 60S WILL LEAD TO MORE FOG
DEVELOPMENT TOWARDS WEDNESDAY MORNING. TIMING OF THE NEXT UPPER
WAVE SEEMS TO BE MORE LATER WEDNESDAY INTO THE EVENING AND
OVERNIGHT. THOUGH THE TRACK...WITH THE SURFACE BOUNDARY SLIDING A
BIT FURTHER SOUTH WILL MAKE FOR A FURTHER TRACK TO THE SOUTH FOR
THE SURFACE LOW. THIS STILL IS A BIT OF QUESTION AS THE TAM AND
THE GFS HAVE BEEN A BIT INCONSISTENT. NEVERTHELESS...WITH THE
BOUNDARY STILL OVER THE SOUTH AND PLENTY OF INSTABILITY DEVELOPING
THROUGH THE DAY...WILL KEEP PRECIP CHANCES IN THE FORECAST
THROUGH WEDNESDAY AFTERNOON AND INTO THE EVENING. IF THE MODELS
ARE CORRECT IN THE BOUNDARY LIFTING NORTH ANY SOONER...POPS WILL
NEED TO BE INCREASED. FOR NOW...WILL ANTICIPATE UNORGANIZED
CONVECTION AND DIURNALLY DRIVEN CONVECTION...AT LEAST THROUGH
WEDNESDAY AFTERNOON.

.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 529 AM EDT TUE AUG 4 2015

THE MODELS ARE IN GENERAL AGREEMENT WITH A MODESTLY AMPLIFIED LONG
WAVE PATTERN TO START OUT IN THE EXTENDED...FEATURING AN UPPER
LEVEL RIDGE NEAR THE DESERT SOUTHWEST...WITH TROUGHING IN THE
MISSISSIPPI VALLEY AND NEAR THE CONTINENTAL DIVIDE. THROUGH THE
WEEKEND...TROUGHING WILL BE MORE CONFINED TO THE EASTERN
SEABOARD...WITH THE RIDGE SHIFTING EAST TOWARDS THE ARKLATEX
REGION. BY EARLY NEXT WEEK...THE PATTERN WILL AMPLIFY...WITH
TROUGHING IN THE FAR WEST...AND OVER THE GREAT LAKES/OHIO VALLEY
REGIONS...WHILE THE RIDGE HOLDS FAST ACROSS THE MIDDLE OF THE
CONUS. DETAILS ASSOCIATED WITH THE EVOLUTION OF THE PATTERN
REMAIN LOWER CONFIDENCE...ESPECIALLY FOR THE SECOND HALF OF THE
PERIOD. AS SUCH...STAYED PRETTY CLOSE TO THE OFFERED BLENDED
GUIDANCE.

POPS WILL BE RAMPING UP TO LIKELY ACROSS EASTERN KENTUCKY THROUGH
THURSDAY AND THURSDAY NIGHT...AS A MORE DEFINED MID-LEVEL WAVE
ALONG WITH A SURFACE FRONT TAKE AIM AT THE AREA. THE BOUNDARY WILL
LINGER CLOSE BY THROUGH FRIDAY...BEFORE SAGGING SOUTHEAST AND
DISSIPATING BY NEXT WEEKEND TO ALLOW FOR MAINLY DRY WEATHER. AS
THE TROUGH AMPLIFIES ACROSS THE OHIO VALLEY NEXT WEEKEND...THE
BOUNDARY WILL SHARPEN UP IN THE VICINITY...HOWEVER GIVEN THE
LOWER CONFIDENCE ON HOW ALL OF THIS TAKES PLACE...WILL STICK WITH
THE RETURN OF ONLY SLIGHT CHANCE POPS BY MONDAY. TEMPERATURES
WILL AVERAGE NEAR NORMAL THROUGH THE PERIOD.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 755 AM EDT TUE AUG 4 2015

RAINFALL OVER THE PAST 12 HOURS AND LIGHT WINDS HAS ALLOWED FOR
FOG DEVELOPMENT THIS MORNING. THIS SHOULD DISSIPATE SHORTLY AFTER
13Z. HEADING INTO THIS AFTERNOON...CONVECTION WILL AGAIN ERUPT
ALONG THE STALLED BOUNDARY. HAVE PUT IN VCTS OVER THE
JKL...LOZ...AND SME SITES AS THESE AREAS AND SOUTH WILL HAVE
ENOUGH GRADIENT AND INSTABILITY FOR THUNDERSTORM DEVELOPMENT THIS
AFTERNOON. OTHERWISE...VFR CONDITIONS WILL BE EXPECTED THROUGH
THE DAY. SUBSIDENCE DEVELOPING IN THE FORM OF HIGH PRESSURE
PASSING BY TO THE NORTH AND LIGHT WINDS TONIGHT AFTER THUNDERSTORM
ACTIVITY DIES OFF AFTER 00Z TONIGHT. HAVE PUT SOME IFR AND BELOW
CIGS AND VIS AT THE TAF SITES.


&&

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

$$

UPDATE...SBH
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.