000
FXUS63 KPAH 120919
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
419 AM CDT SUN MAY 12 2013

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 359 AM CDT SUN MAY 12 2013

MAIN FORECAST ISSUE IN THE NEAR TERM LIES WITH THE FROST POTENTIAL
TONIGHT. MODELS ARE IN DECENT AGREEMENT WITH THE OVERALL SYNOPTIC
PATTERN THROUGH EARLY NEXT WEEK. CHILLY CANADIAN HIGH PRESSURE
WILL BUILD SOUTHEAST OVER THE REGION LATER TODAY AND TONIGHT.
THIS WILL SET UP IDEAL RADIATIONAL COOLING CONDITIONS OVER MOST OF
THE REGION DURING THE OVERNIGHT HOURS. THE EXCEPTION LOOKS LIKE IT
MAY BE OUR FAR SWRN COUNTIES WEST OF THE MS RIVER...WHERE WARM
ADVECTION MID/HIGH CLOUDS MAY DISRUPT THESE CONDITIONS.
ELSEWHERE...NEAR RECORD COLD WILL LIKELY BE EXPERIENCED...WITH
OVERNIGHT LOWS IN THE MID/UPPER 30S. THIS COULD LEAD TO PATCHY
FROST...ESPECIALLY IN THOSE COLDER OUTLYING AND SHELTERED AREAS
THAT NORMALLY RUN A BIT COLDER THAN OUR MAIN AIRPORTS. FOR
NOW...WILL OPT TO ISSUE AN SPS TO ADDRESS THE PATCHY FROST
POTENTIAL...AND LET THE DAY SHIFT TAKE ANOTHER LOOK AS TO WHERE
CLOUDS/DEW POINTS ARE GOING TO END UP.

AFOREMENTIONED WARM ADVECTION WILL GET UNDERWAY AREA WIDE
MONDAY/TUESDAY AS THE SFC HIGH DRIFTS OFF TO THE EAST. LOOK FOR
RAINFREE CONDITIONS AND A RAPID WARM UP TO ABOVE NORMAL TEMPS
/LOWER TO MID 80S/ BY TUESDAY AFTERNOON.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 359 AM CDT SUN MAY 12 2013

PERSISTENT SOUTHWEST LOW LEVEL FLOW WILL BRING WARM AND
INCREASINGLY HUMID AIR THROUGH THE WEEK. THE 500 MB MEAN RIDGE
POSITION WILL BE IN THE VICINITY OF THE MISSISSIPPI VALLEY.
HOWEVER...THERE WILL BE LOW CHANCES OF SHOWERS AND STORMS FOR MUCH
OF THE PERIOD DUE TO WEAK SHORTWAVES PENETRATING THE RIDGE.

AS FAR AS THE DAILY DETAILS...TUESDAY NIGHT AND WEDNESDAY WILL BE
WARM AND DRY AS THE UPPER LEVEL RIDGE MOVES ACROSS THE AREA.
FORECAST 850 MB TEMPS IN THE MID TEENS SUPPORT HIGHS IN THE MID
80S...WHICH IS IN GOOD AGREEMENT WITH MOS GUIDANCE.

PRECIP CHANCES WILL GRADUALLY INCREASE FROM THE WEST WEDNESDAY NIGHT
AS A 500 MB SHORTWAVE ATTEMPTS TO LIFT NORTHEAST FROM THE SOUTHERN
PLAINS. THE 00Z GUIDANCE SUITE BASICALLY DISINTEGRATES THE SHORTWAVE
AS IT PASSES ACROSS THE LOWER/MID MISSISSIPPI VALLEY ON THURSDAY.
HOWEVER...THERE WILL BE PLENTIFUL MOISTURE AND INSTABILITY...WHICH
WILL LIKELY RESULT IN SCATTERED SHOWERS/STORMS. GFS SURFACE BASED
CAPES APPROACH 2000 J/KG THURSDAY AFTERNOON. GFS PW VALUES AVERAGE
NEAR 1.5 INCHES. DUE TO CLOUDS/POTENTIAL PRECIP...HIGH TEMPS SHOULD
BE A LITTLE COOLER. WILL FORECAST HIGHS IN THE UPPER 70S...WHICH IS
A LITTLE BELOW GFS MOS.

FRIDAY THROUGH SATURDAY...THE RIDGE WILL RESTRENGTHEN OVER THE
MISSISSIPPI VALLEY AS THE REMNANTS OF THE SHORTWAVE DISSIPATE TO OUR
EAST. MODELS DEPICT AN INCREASINGLY MOIST AND UNSTABLE AIR MASS
UNDER THE RIDGE...WITH GFS/ECMWF 2 METER DEW POINTS CLIMBING TO
AROUND 70 ON SATURDAY AFTERNOON. GIVEN THE SOUPY NATURE OF THE AIR
MASS AND MODEL INDICATIONS OF WEAK IMPULSES WITHIN THE RIDGE...POPS
WILL BE IN THE LOW CHANCE CATEGORY FRIDAY AND SATURDAY. WILL
FORECAST HIGHS IN THE LOWER 80S BOTH DAYS...A FEW DEGREES LOWER THAN
GFS MOS DUE TO POTENTIAL CLOUDS/PRECIP.

&&

.AVIATION...
ISSUED AT 350 AM CDT SUN MAY 12 2013

VFR CONDITIONS EXPECTED AT ALL SITES THROUGH THE PERIOD. NORTHERLY
WINDS AOB 10 KTS EARLY WILL GUST UP TO 15-18 KTS BETWEEN 15-23Z.

&&

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

$$

SHORT TERM...GM
LONG TERM...MY
AVIATION...JP