Area Forecast Discussion
Issued by NWS Paducah, 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 KPAH 250842
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
342 AM CDT SAT JUL 25 2015

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 341 AM CDT SAT JUL 25 2015

MAIN NEAR TERM CONCERNS INCLUDE: (1.) THE POTENTIAL FOR SHOWERS
AND THUNDERSTORMS; AND (2.) THE BUILDING HEAT AND HUMIDITY THROUGH
MONDAY. GIVEN THE UNCERTAINTY OVER CONVECTIVE POTENTIAL AND ITS
IMPACT ON TEMPERATURES...CONFIDENCE IS AVERAGE TO BELOW AVERAGE IN
THE NEAR TERM.

THE UPPER LEVEL HIGH WILL REMAIN IN PLACE ACROSS THE SOUTHERN
STATES THROUGH EARLY IN THE NEW WEEK. IMPULSES OF ENERGY STREAMING
SOUTHEASTWARD ALONG THE NORTHERN PERIPHERY OF THIS HIGH WILL YIELD
THE POTENTIAL FOR CONVECTIVE COMPLEXES AS OBSERVED IN MISSOURI
OVERNIGHT. THE 00Z NAM AND HI-RES ARW-WRF APPEAR TO HAVE THE BEST
HANDLE ON THIS CONVECTION. BOTH MODELS BRING THE THUNDERSTORM
COMPLEX INTO SOUTHEAST MISSOURI EARLY THIS MORNING BEFORE ITS
EVENTUAL DEMISE. ADDITIONAL BOUNDARY-DRIVEN DIURNAL DEVELOPMENT
ALSO CANNOT BE RULED OUT THIS AFTERNOON...ESPECIALLY OVER
SOUTHEAST MISSOURI WHERE HUMIDITY WILL BE SUBSTANTIALLY HIGHER.

THE CONVECTIVE DEBRIS CLOUDS MAY IMPACT TEMPERATURES...ESPECIALLY
WEST OF THE MISSISSIPPI RIVER THIS MORNING. HOWEVER...A TREND
TOWARDS MORE CLEARING IS EXPECTED BY AFTERNOON. THIS SHOULD ALLOW
TEMPERATURES TO REACH THE LOWER 90S ACROSS MOST OF THE AREA. GIVEN
THE PERSISTENCE OF A SHARP WEST-EAST DEW POINT GRADIENT...HEAT
INDEX VALUES SHOULD REMAIN BELOW 105 OVER ALL BUT A HANDFUL OF OUR
MISSOURI COUNTIES THIS AFTERNOON. WILL ISSUE A HEAT ADVISORY FOR
LOCATIONS GENERALLY ALONG AND WEST OF A GREENVILLE TO NEW MADRID
MISSOURI LINE.

ANOTHER THUNDERSTORM COMPLEX IS FORECAST TO DEVELOP UPSTREAM OVER
THE MISSOURI VALLEY TONIGHT...THEN HEAD SOUTHEAST INTO NORTHERN
PORTIONS OF THE QUAD STATE REGION LATE TONIGHT AND SUNDAY MORNING.
THE ACTIVITY WILL LIKELY DISSIPATE THROUGH THE MORNING AS IT LOSES
SUPPORT. IT IS LIKELY THAT DEBRIS CLOUDS WILL HAVE AN IMPACT ON
TEMPERATURES ON SUNDAY AS WELL. SO BELIEVE THE BEST APPROACH IS TO
TAKE THE HEAT HEADLINES ONE DAY AT A TIME FOR NOW.

BY MONDAY...THE INFLUENCE OF THE UPPER LEVEL HIGH WILL BECOME MORE
NOTICEABLE AS PRECIPITATION CHANCES BEGIN TO SHIFT NORTHEAST AND
DWINDLE. HEAT AND HUMIDITY WILL TAKE HOLD WITH HIGHS IN THE LOWER
90S AND HEAT INDEX READINGS OF AT LEAST 100 TO 105 ACROSS MOST OF
THE AREA.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 341 AM CDT SAT JUL 25 2015

AVERAGE TO BELOW CONFIDENCE IN THE LONG TERM AS MODELS NOT IN GOOD
AGREEMENT ON PLACEMENT AND STRENGTH OF SYNOPTIC FEATURES.

THE LONG TERM PERIOD STARTS OFF WITH AN H5 RIDGE STRETCHING
NORTHEAST ACROSS OUR CWA. ALTHOUGH MODELS NOT IN GOOD AGREEMENT ON
THE STRENGTH OF THE RIDGE AND THE PLACEMENT OF ITS AXIS...THE
PRESENCE OF THE RIDGE AND WARM MID LEVEL AIR (AOA 10C) COINCIDENT
WITH IT SHOULD PRECLUDE THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS
OVER ALL EXCEPT THE FAR NORTHEAST SECTIONS OF OUR CWA MONDAY NIGHT
AND TUESDAY.

MODELS SHOW THE RIDGE BUILDING A BIT TUESDAY NIGHT SO NO ACTIVITY
EXPECTED IN THAT PERIOD. PRECIPITATION CHANCES MAKE THEIR WAY BACK
INTO THE FORECAST ON WEDNESDAY AS UPPER LEVEL ENERGY ATTEMPTS TO
PUSH A FRONTAL BOUNDARY OUT OF THE PLAINS TOWARD OUR AREA. THIS
SHOULD SUPPRESS THE RIDGE AND WARM AIR ALOFT ENOUGH TO ALLOW THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS AREA WIDE. AGAIN MODELS NOT
IN AGREEMENT ON TIMING AND PLACEMENT OF QPF...SO JUST WENT WITH SCHC
POPS FOR NOW.

THE AFOREMENTIONED BOUNDARY IS FORECAST TO CROSS OUR CWA WEDNESDAY
NIGHT. THEORETICALLY SPEAKING THIS SHOULD WARRANT POPS ACROSS OUR
ENTIRE CWA LIKE THE GFS INDICATES BUT FOR SOME REASON THE ECMWF JUST
SHOWS PRECIPITATION CHANCES OVER THE NORTHEAST HALF OF OUR CWA.
DECIDED TO GO WITH HIGHER POPS (CHC) OVER THE NORTHEAST HALF AND THE
LOWEST POSSIBLE POPS (15) TO GENERATE PRECIPITATION WORDING OVER THE
SOUTHWEST HALF JUST IN CASE THE GFS VERIFIES.

MODELS NOT IN GOOD AGREEMENT AT ALL ON THURSDAY. IN THE WAKE OF THE
FRONTAL PASSAGE THE ECMWF HAS ALL PRECIPITATION SOUTHEAST AND EAST
OF OUR CWA WHILE THE GFS HANGS UP LIGHT PRECIPITATION OVER OUR CWA
ALL DAY. THIS MAKES NO SENSE SYNOPTICALLY BECAUSE EVEN WITH WEAK
WEST NORTHWEST FLOW ALOFT IT SHOULD BE ENOUGH TO PUSH THE DEEPER
MOISTURE TO OUR SOUTH AND EAST. FOR POPS DECIDED TO SPLIT THE
DIFFERENCE (HIGHER POPS SOUTHEAST...LOWER POPS NORTHEAST) TO IMPLY
AT LEAST LOWERING POPS AND FOR BETTER COLLABORATION.

MODELS IN BETTER AGREEMENT THURSDAY NIGHT AND FRIDAY IN THAT DRIER
HIGH PRESSURE OVERSPREADING THE REGION IN THE WAKE OF THE FRONT
SHOULD BRING PRECIPITATION CHANCES TO END AS WELL AS LOWERING
TEMPERATURES AND DEWPOINTS TO MORE TOLERABLE LEVELS.&&

.AVIATION...
ISSUED AT 1142 PM CDT FRI JUL 24 2015

MVFR FOG POSSIBLE MAINLY AT KPAH/KEVV/KOWB BETWEEN 07Z-13Z. MID-
HIGH CLOUDS EXTENDING FROM THUNDERSTORM COMPLEX OVER MISSOURI WILL
MAINLY AFFECT KCGI/KPAH OVERNIGHT. KCGI CIGS COULD BRIEFLY DIP TO
MVFR THROUGH 12Z. CALM TO LIGHT AND VARIABLE WINDS OVERNIGHT WILL
BECOME SOUTHWEST AROUND 5 KTS AFTER 13Z.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
     MOZ100-107>110-114.

IN...NONE.
KY...NONE.
&&

$$

SHORT TERM...RJP
LONG TERM...JP
AVIATION...RST



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