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 300840
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
440 AM EDT TUE JUN 30 2015

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 440 AM EDT TUE JUN 30 2015

AMPLIFIED PATTERN REMAINS IN PLACE WITH RIDGING ACROSS THE
WESTERN CONUS AND TROUGHING ACROSS THE EASTERN CONUS. SHORT WAVES
CONTINUE TO ROTATE THROUGH THE BASE OF THE EASTERN TROUGH...BEING
THE MAIN DRIVER OF OUR WEATHER THROUGH THE SHORT TERM. MODELS
CONTINUE TO SHOW GOOD AGREEMENT WITH OVERALL PATTERN...WITH ONLY
DIFFERENCES SHOWING UP WITH RESPECT TO TIMING AND STRENGTH OF
PASSING SHORT WAVES.

AREA OF CONVECTION HAS STALLED OUT ACROSS CENTRAL AND EASTERN TN.
THERE HAS ALSO BEEN SOME PERSISTENT LIGHT RAIN NORTH OF THE TN
STATE LINE JUST INSIDE OUR CWA AS WELL. RECENT RUN OF THE HRRR
HAS THIS AREA OF CONVECTION LIFTING BACK UP TO THE NE THIS
MORNING...CATCHING A PORTION OF OUR CWA. RADAR TRENDS APPEAR TO BE
TRENDING IN THAT DIRECTION THOUGH NOT AS STRONGLY AS THE HRRR
WOULD SUGGEST. ADDED SOME HIGHER POPS AND REINTRODUCED SOME ISOLD
THUNDER FOR THE FAR SOUTHEAST TO ACCOUNT FOR THIS POSSIBILITY.

ANOTHER IN THE CURRENT SERIES OF DISTURBANCES WILL DROP INTO THE
REGION LATER TODAY...PRODUCING ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS. BASED ON CURRENT FORECAST SOUNDINGS...MARGINAL TO
AT BEST MODEST SHEAR AND SFC BASED INSTABILITY SUGGESTS THE
POTENTIAL FOR A FEW SEVERE STORMS THIS AFTERNOON AND EARLY THIS
EVENING...SIMILAR TO MONDAY. IN ADDITION...SPC CONTINUES TO CARRY
OUR AREA IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS TODAY. AS SUCH
WILL MENTION THE POTENTIAL THREAT IN OUR HWO.

.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 344 AM EDT TUE JUN 30 2015

LONG RANGE MODELS ARE STILL IN VERY GOOD AGREEMENT STARTING OUT
THURSDAY WITH A DEEP LONGWAVE TROUGHING PATTERN SETTING UP ACROSS
MUCH OF THE EASTERN CONUS AND REMAINING IN PLACE THROUGH MUCH OF THE
WEEKEND...WHILE SLOWLY DAMPENING. THIS PULL OF NORTHERLY AIR WILL
KEEP TEMPERATURES BELOW NORMAL THROUGH THE WEEKEND AS WELL.
MULTIPLE SHORTWAVES WILL TRAVERSE THE LONGWAVE TROUGH...WHICH WILL
LIKELY AFFECT MUCH OF THE OHIO RIVER VALLEY...BRINGING ENHANCED
AREAS OF LIFT FOR SHOWERS AND THUNDERSTORMS...AND EVEN SOME MCS
POTENTIAL. A STRONG UPPER LEVEL LOW WILL GAIN STRENGTH AS IT MOVES
SOUTH INTO SOUTHERN CANADA SUNDAY INTO MONDAY. THIS WILL DAMPEN THE
TROUGH ACROSS THE EASTERN CONUS...BUT WILL KEEP A WEAK NW FLOW
REGIME ACROSS THE OHIO RIVER VALLEY. THE UPPER LEVEL LOW WILL THEN
SHIFT EASTWARD MONDAY NIGHT INTO TUESDAY...DIRECTLY IMPACTING THE
UPPER GREAT LAKES. EXPECT ENERGY FROM THIS SYSTEM TO IMPACT AS FAR
SOUTH AS KENTUCKY TO END OUT THE FORECAST PERIOD. CONFIDENCE REMAINS
LOW...HOWEVER...FOR THIS LATE WEEKEND/EARLY WORK WEEK SYSTEM...AS
THE GFS AND ECMWF ARE STILL SHOWING SOME DISAGREEMENT ON TIMING AND
PLACEMENT.

AS FOR SENSIBLE CONDITIONS...THE NW FLOW AND SHORTWAVES WILL PRODUCE
A SERIES OF FRONTAL BOUNDARIES AND SPARKS FOR SHOWERS AND
THUNDERSTORMS. THE FIRST OF THESE BOUNDARIES WILL HAVE MOVED INTO
THE OHIO VALLEY REGION TO START OFF THE EXTENDED PERIOD...AND WILL
OSCILLATE NORTH AND SOUTH BUT REMAIN OVERALL RATHER STATIONARY
THROUGH THE FIRST PART OF THE WEEKEND. MEANWHILE...NUMEROUS
LOCALIZED SURFACE LOW PRESSURE SYSTEMS WILL BE DRIVEN BY UPPER LEVEL
SHORTWAVES AND GENERALLY PUSH ACROSS SOUTHERN KY AND TN. THIS IS
WHERE THE BULK OF THE MOISTURE AND MCS POTENTIAL WILL LIE. BY
FRIDAY...THE SHORTWAVE MOVING THROUGH WILL PASS ACROSS THE NORTHERN
PORTION OF THE STATE...AND THE LOCAL SURFACE BOUNDARY WILL ALIGN
ITSELF ALONG THE OHIO RIVER. THIS TIME AROUND...EXPECT BEST MOISTURE
/RAIN AND THUNDER POTENTIAL/ TO MOVE ACROSS THE ENTIRE
STATE...CONTINUING THROUGH MUCH OF THE WEEKEND BUT PEAKING DURING
THE AFTERNOON AND EARLY EVENING HOURS.

IF THE ECMWF MODEL HOLDS TRUE...THE STRENGTHENING UPPER LEVEL LOW
MOVING SE ACROSS CANADA WILL BRING A MUCH STRONGER COLD FRONT ACROSS
THE NORTHERN MISSISSIPPI RIVER VALLEY MONDAY AND INTO THE OHIO RIVER
VALLEY AND POINTS NORTHWARD MONDAY NIGHT INTO TUESDAY. CONFIDENCE ON
TIMING AND THE EXACT FRONTAL LOCATION IS STILL QUITE LOW
HOWEVER...GIVEN THE DISCREPANCIES IN THE GFS AND ECMWF THIS FAR OUT
IN THE FORECAST /AS MENTIONED ABOVE/. STUCK WITH A BLEND OF THESE
MODELS...WHICH LED TO JUST A MENTION OF CHANCE POPS DURING THIS TIME
PERIOD. HOWEVER...THIS SYSTEM COULD BRING ANOTHER STRONG DOSE OF
STRONG SHOWERS AND THUNDERSTORMS /PWATS 2 INCHES AN ABOVE/...AND
POTENTIALLY SOME STRONG WINDS WITH 25 TO 30 KNOTS EXPECTED JUST
ABOVE THE SURFACE AND THROUGH THE MID LEVELS ACCORDING TO THE LATEST
GFS40.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 150 AM EDT TUE JUN 30 2015

CONVECTION HAS ALL BUT ENDED ACROSS SOUTHEASTERN KENTUCKY.
HOWEVER...MODEL GUIDANCE SUGGESTS AN ISOLD POP UP RAIN SHOWER WILL
STILL BE POSSIBLE JUST ABOUT ANYWHERE THROUGH DAWN. MAIN CHALLENGE
IS FOG. MOST RECENT GUIDANCE SUGGEST MVFR CONDITIONS OR BETTER AT
ALL OF OUR TERMINALS...ONLY EXCEPTION BEING SME LIFR CONDITIONS
WILL BE POSSIBLE DURING THE PREDAWN HOURS. GUIDANCE SEEMS
REASONABLE AND THEREFORE STAYED CLOSE TO GUIDANCE FOR GENERAL
FLIGHT CONDITIONS. SCATTERED CONVECTION THREATENS ONCE AGAIN
TUESDAY AFTERNOON. WINDS WILL REMAIN LIGHT THROUGH EARLY MORNING
TUESDAY BEFORE PICKING UP OUT OF THE WEST...SOUTHWEST AT 5 TO 10
KTS DURING THE REMAINDER OF THE DAY ON TUESDAY.


&&

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

&&

$$

SHORT TERM...RAY
LONG TERM...JMW
AVIATION...GEOGERIAN/RAY


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