Severe Thunderstorm Warning 132, NWS Paducah, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
635 PM CDT MON JUL 20 2015

.UPDATE...
ISSUED AT 635 PM CDT MON JUL 20 2015

UPDATED AVIATION DISCUSSION ONLY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 301 PM CDT MON JUL 20 2015

ABOVE AVERAGE CONFIDENCE IN THE SHORT TERM AS MODELS COMING INTO
SOMEWHAT BETTER AGREEMENT.

THIS AFTERNOON SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO FILL IN
ACROSS THE AREA DUE TO THE PRESENCE OF A QUASI-STATIONARY FRONTAL
BOUNDARY BISECTING OUR CWA FROM W-E...A VERY UNSTABLE AIRMASS IN
PLACE...AND WEAK RIPPLES OF UPPER LEVEL ENERGY PASSING OVERHEAD.
WITH SO MUCH INSTABILITY AND INCREASING WIND SHEAR...THERE IS A
SLIGHT CHANCE FOR A FEW STORMS BECOMING SEVERE...WITH DAMAGING
WINDS...LOCALLY HEAVY RAINFALL...AND DEADLY LIGHTNING BEING THE
PRIMARY THREATS.

A COLD FRONT DIVING SOUTHEAST OUT OF THE PLAINS WILL PUSH THE
AFOREMENTIONED BOUNDARY ACROSS THE REMAINDER OF OUR REGION THIS
EVENING. AS RESULT... PRECIPITATION CHANCES INCREASE THIS EVENING
INTO THE EARLY OVERNIGHT HOURS. BEYOND THAT PRECIPITATION SHOULD
DIMINISH FROM NORTH TO SOUTH AND BY FIRST THING TUESDAY MORNING
PRECIPITATION SHOULD BE LIMITED TO THE SOUTHERN HALF OF THE AREA.

THE WESTERN PORTION OF THE SECOND FRONT IF FORECAST TO HANG UP JUST
SOUTH AND WEST OF OUR CWA TUESDAY. ZONAL FLOW ALOFT COMBINED WITH
DEEP MOISTURE POOLED ALONG AND SOUTH OF THE BOUNDARY WILL SET UP AN
OVERRUNNING SCENARIO WHICH WILL SPREAD PRECIPITATION SLOWLY
NORTHEAST ACROSS OUR CWA FROM TUESDAY AFTERNOON THROUGH THE END OF
THE PERIOD.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 301 PM CDT MON JUL 20 2015

MID LEVEL SHRTWV ENERGY IN THE SLIGHTLY CYCLONIC NRN STREAM FLOW
JUST TO THE NORTH OF A DEEP SOUTH RIDGE IS PROGGED TO BE IN THE
VICINITY OF THE PAH FORECAST AREA AT THE BEGINNING OF THE EXTENDED
FORECAST PERIOD. THIS...COMBINED WITH A SFC FRONTAL BOUNDARY IN OR
NEAR SWRN PARTS OF OUR REGION...WILL PROBABLY TAP ENOUGH MOISTURE
AND INSTABILITY FOR SCATTERED SHOWER AND TSTM DEVELOPMENT DURING THE
HEATING OF THE DAY THU...MAINLY IN THE SWRN HALF OF THE REGION. POPS
DIMINISH THROUGH FRI NIGHT AS ANTI-CYCLONIC MID LEVEL FLOW
BEGINS TO TAKE OVER.

A MORE MERIDIONAL TYPE SHRTWV IS SHOWN BY THE MED RANGE MODELS TO
IMPINGE ON THE EXPANDING SRN CONUS RIDGE BY SAT. THIS COULD RESULT
IN ISOLATED SHOWER AND TSTM ACTIVITY IN PARTS OF THE REGION...
DESPITE SUBSIDENCE FROM THE RIDGE. THE LINGERING FRONTAL BOUNDARY
WEST OF THE MS RIVER MAY ENHANCE SOME CONVECTION. DRIER AIR SHOULD
TEND TO MOVE INTO OUR REGION FROM THE NW BY SAT NIGHT AND INTO
SUNDAY. THERE IS UNCERTAINTY AS TO WHETHER ADDITIONAL NRN STREAM
SHRTWV ENERGY SUN NIGHT WILL BE ENOUGH TO GENERATE SCATTERED
CONVECTION AGAIN IN OUR REGION. FOR NOW THERE ARE SOME POPS FOR IT
IN THE FORECAST...SUBJECT TO CHANGE. FOR EXAMPLE...THE 12Z ECMWF HAS
TRENDED DRIER.

EXPECT A WARM-UP BACK INTO THE 90S FROM THE LATTER HALF OF THE
WEEKEND ON...AS HEIGHTS RISE. HUMIDITY WILL CONTINUE TO BE ON THE
RATHER HIGH SIDE.

&&

.AVIATION...
ISSUED AT 635 PM CDT MON JUL 20 2015

SCATTERED SHOWERS AND TSTMS AHEAD OF A COLD FRONT HAVE DEVELOPED...
AND WILL MOVE EWD ACROSS THE PAH FORECAST AREA MOSTLY DURING THE
EVENING HOURS. VSBYS WILL PROBABLY GO IFR IN HEAVIER CONVECTION...
WITH MVFR CIGS LIKELY. SOME STORMS MAY RESULT IN GUSTY WINDS...AND
MAY BE SEVERE. IN THE WAKE OF THE CONVECTIVE SYSTEM...INCREASINGLY
NWRLY WINDS...GENERALLY BELOW 10 KTS...SHOULD PREVAIL BEHIND THE
FRONT LATER TONIGHT AND TUE. SOME MVFR/IFR FOG IS POSSIBLE AT ALL
TAF SITES LATE IN THE NIGHT.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

SHORT TERM/FIRE WX...JP
LONG TERM/AVIATION...DB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PADUCAH KY
309 PM CDT MON JUL 20 2015

ILZ075>078-080>094-INZ081-082-085>088-KYZ001>022-MOZ076-086-087-
100-107>112-114-212015-
JEFFERSON-WAYNE IL-EDWARDS-WABASH-PERRY IL-FRANKLIN-HAMILTON-
WHITE-JACKSON-WILLIAMSON-SALINE-GALLATIN-UNION IL-JOHNSON-POPE-
HARDIN-ALEXANDER-PULASKI-MASSAC-GIBSON-PIKE-POSEY-VANDERBURGH-
WARRICK-SPENCER-FULTON-HICKMAN-CARLISLE-BALLARD-MCCRACKEN-GRAVES-
LIVINGSTON-MARSHALL-CALLOWAY-CRITTENDEN-LYON-TRIGG-CALDWELL-
UNION KY-WEBSTER-HOPKINS-CHRISTIAN-HENDERSON-DAVIESS-MCLEAN-
MUHLENBERG-TODD-PERRY MO-BOLLINGER-CAPE GIRARDEAU-WAYNE MO-CARTER-
RIPLEY-BUTLER-STODDARD-SCOTT-MISSISSIPPI-NEW MADRID-
309 PM CDT MON JUL 20 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHERN
ILLINOIS...SOUTHWEST INDIANA...WESTERN KENTUCKY AND SOUTHEAST
MISSOURI.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS SOUTHEAST
MISSOURI AND SOUTHERN ILLINOIS THIS AFTERNOON....THEN BECOME MORE
NUMEROUS THROUGHOUT THE REGION TONIGHT...AS A COLD FRONT ENTERS
THE AREA. A FEW OF THE STORMS THIS AFTERNOON COULD BECOME SEVERE
WITH LARGE HAIL AND DAMAGING WINDS POSSIBLE. DAMAGING WINDS WILL
BE THE PRIMARY SEVERE WEATHER CONCERN TONIGHT. LOCALLY HEAVY RAIN
AND LIGHTNING WILL ALSO BE CONCERNS THIS AFTERNOON AND TONIGHT.

HEAT INDEX VALUES ARE EXPECTED TO WARM TO AROUND 105 DEGREES THIS
AFTERNOON OVER FAR SOUTHEAST MISSOURI.

FLOODING WILL CONTINUE ALONG THE WABASH...OHIO AND MISSISSIPPI
RIVERS. PLEASE REFER TO THE LATEST RIVER FLOOD WARNINGS AND
STATEMENTS FOR DETAILS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

CHANCES OF THUNDERSTORMS ARE FORECAST FOR ALL OR A PORTION OF THE
AREA FROM TUESDAY THROUGH SUNDAY. THE BEST CHANCES THROUGH THE
PERIOD WILL PERSIST OVER SOUTHEAST MISSOURI...AND THE GREATEST
CHANCE WILL BE ON THURSDAY. LOCALLY HEAVY RAINFALL AND LIGHTNING
WILL BE THE PRIMARY CONCERNS THROUGH THE PERIOD.

FLOODING WILL CONTINUE ALONG THE MISSISSIPPI...OHIO...AND WABASH
RIVERS. PLEASE REFER TO THE LATEST RIVER FLOOD WARNINGS AND
STATEMENTS FOR DETAILS.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS SHOULD BE PREPARED FOR ACTIVATION THIS AFTERNOON AND
EVENING.

JP