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000
FXUS63 KPAH 170805
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
305 AM CDT FRI MAY 17 2013

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 251 AM CDT FRI MAY 17 2013

SATELLITE SHOWS THE UPPER LOW SWIRLING INTO SOUTHEAST MO. RADAR
DEPICTS OVERRUNNING SHOWERS IN ADVANCE OF THE LOW`S
APPROACH...SPREADING/EXPANDING OVER THE PAH FA. MODELS FAIRLY
NEGOTIATE THE MOVEMENT OF THE LOW SOUTHWEST TO NORTHEAST ACROSS
THE PAH FA TODAY...WITH THE ASSOCIATED SHOWERS/STORM CHANCE
MOVEMENT LIKEWISE ASSOCIATED. HAVE MASSAGED GRIDS TO ACCOUNT FOR
LATEST PLACEMENT/PEAK POPS IN LIKELY CAT.

WHILE THE OPEN WAVED LOW LIFTS NORTHEAST INTO THE MIDDLE OHIO
RIVER VALLEY TONIGHT...SUFFICIENT LINGERING HIGH LAYER
MRH/INSTABILITY WILL LINGER POPS INTO THE WEEKEND. NOT UNTIL SAT
NIGHT-SUNDAY DOES THE TELECONNECTED RIDGE BUILD INTO THE AREA IN
THE WAKE OF THE WAVES DEPARTURE AND THEREBY DISENGAGE THE DAILY
POP. MODELS STILL TRY TO PAINT A LITTLE QPF THEN BUT WE`D PREFER TO
PLAY THAT PERIOD DRY AS WE AWAIT THE NEXT SYSTEM TO COME IN EARLY
NEXT WEEK. WE`LL MONITOR COLLAB PROCESS AND PAINT A SLGT CHC
MENTION IF NECESSARY.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 251 AM CDT FRI MAY 17 2013

TO BEGIN THE PERIOD SUNDAY NIGHT INTO MONDAY...THE 00Z GFS AND ECMWF
AGREE IN THE FORECAST AREA BEING IN A WELL-CAPPED WARM SECTOR OF A
NEARLY OCCLUDED STORM SYSTEM CENTERED OVER THE NORTHERN PLAINS.

THE 00Z ECMWF HAS SHIFT NORTHWARD WITH THE PATH OF THIS SYSTEM
THROUGH THE WEEK. IT NO LONGER DIVES IT OVER OUR REGION...WHICH
SHOULD LEAD TO A WARMER MID-WEEK THAN EXPECTED YESTERDAY. GIVEN THE
LACK OF A SIGNIFICANT LOW-LEVEL BAROCLINIC ZONE...AND THE WEAKENING
NATURE OF THIS SYSTEM...TRYING TO TIME THE BEST CHANCES FOR
CONVECTION OVER OUR REGION IS LESS CERTAIN THAN YESTERDAY.

WOULD STILL EXPECT AN INCREASE AT LEAST OVER THE WESTERN THIRD TO
HALF OF THE AREA AT SOME POINT MONDAY NIGHT INTO TUESDAY...WITH A
SLOW EASTWARD SHIFT THROUGH THE AREA THROUGH WEDNESDAY. WE SHOULD BE
DRYING OUT THURSDAY AS SURFACE HIGH PRESSURE BEGINS TO FILTER OVER
THE AREA. BOTH MODELS ADVERTISE A SURGE OF CANADIAN SURFACE HIGH
PRESSURE SOUTHWARD OVER THE REGION FRIDAY. TEMPERATURES WILL BE
WARMEST ON MONDAY...BUT SHOULD BE AT OR ABOVE NORMAL THROUGH
THURSDAY. OF COURSE WOULD EXPECT READINGS TO FALL BELOW NORMAL FOR
FRIDAY.

THIS SURGE OF HIGH PRESSURE FRIDAY IS THE RESULT OF A MAJOR PATTERN
SHIFT ADVERTISED BY BOTH MODELS. THEY ADVERTISE A DEEP
TROUGH/LOW OVER THE WEST COAST...WITH A FULL-LATITUDE UPPER RIDGE
THROUGH THE PLAINS AND MIDWEST. HOW DEEP THE GREAT LAKES/NORTHEAST
TROUGH/LOW WILL BE IS THE BIGGEST QUESTION BETWEEN THE MODELS. THE
ECMWF CONTINUES TO BE DEEPER...BUT HAS SHIFTED DRAMATICALLY
NORTHWARD COMPARED TO ITS RUN FROM 24 HOURS AGO...SO WOULD TEND TO
BELIEVE THE LESS-AMPLIFIED GFS.

WE SHOULD BE UNDER THE INFLUENCE OF HIGH PRESSURE AT THE SURFACE AND
ALOFT TO BEGIN THE MEMORIAL DAY WEEKEND. GIVEN THE BLOCKY NATURE OF
THE PATTERN WOULD EXPECT MOST OF THE HOLIDAY WEEKEND TO BE QUITE
PLEASANT AND DRY.

&&

.AVIATION...
ISSUED AT 251 AM CDT FRI MAY 17 2013

VFR CIGS ARE THE RULE AT THIS WRITING...BUT A MOVE TO MVFR IS
POSSIBLE AT TIMES AS THE UPPER LOW LIFTS ACROSS SEMO THIS MORNING
AND HELPS SPREAD ONGOING SHOWERS NORTHEASTWARD ACROSS THE FLIGHT
TERMINALS. THIS MAY INCLUDE MVFR VSBYS IN SHOWERS/CHANCE OF
THUNDERSTORM. THE LOW WILL BE SLOW TO MOVE ACROSS THE AREA SO
CONTINUED VFR/OCNL MVFR CONDITIONS TIL ITS PASSAGE ARE EXPECTED.

&&

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

$$