000
FXUS63 KPAH 180927
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
427 AM CDT SAT MAY 18 2013

.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 306 AM CDT SAT MAY 18 2013

DENSE FOG HAS DEVELOPED UNDER THE CLEARED SKIES WEST OF THE
MISSISSIPPI...AND SHOULD EXPAND TO INCLUDE NEARBY MS RIVER
COUNTIES IN SW IL/FAR SW KY. DEPENDING UPON THE SKY COVER...IT
COULD FURTHER PROTRUDE EASTWARD...BUT LATEST 11-3.9U IMAGERY
SUGGESTS THE LOW CLOUDS (PATCHY DRIZZLE/MIST) WILL MORE OR LESS
PERSIST FURTHER EAST. COLLABORATED/ISSUED DENSE FOG ADVISORY FOR
WESTERN PTNS AFOREMENTIONED.

WITH THE OPEN WAVED LOW MOVING FURTHER NORTHWARD/EASTWARD UP THE
OHIO VALLEY TODAY...LINGERING HIGH MRH PARTICULARLY IN OUR EAST
WILL ALLOW INSTABILITY SHOWERS/STORMS TO FIRE DAYTIME TODAY. MEAN
500 MB RIDGE WILL WORK INTO THE REGION FROM THE WEST IN THE WAKE
OF THE LOW`S DEPARTURE...AND SHOULD PROCLUDE MOST ACTIVITY IN THE
SAT NIGHT-SUN NIGHT TIME FRAME. HOWEVER THE MODELS HAVE BEEN
FAIRLY CONSISTENTLY PAINTING A RIBBON OF LINGERING HIGHER
MRH WITH LIGHT QPF ON THE LEE OF THE RIDGE...SO WE`VE MAINTAINED
OUR GOING SLGT CHANCE MENTION THERE FOR NOW.

AS THE MEAN UPPER RIDGE MOVES EAST MONDAY...HEIGHT FALLS TO OUR
WEST WILL HELP DEVELOP/EAST A LOW PRESSURE SYSTEM/ASSOCIATED COLD
FRONT TOWARD THE FA LATER MONDAY INTO MONDAY NIGHT. ACCOMPANYING
THIS SYSTEM IS A SLGT RISK OF SVR ALONG/AHEAD OF ITS
APPROACH...WHICH TOUCHES INTO OUR NORTHWESTERN COUNTIES MON-MON
NITE VISA VI SWODY3.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 306 AM CDT SAT MAY 18 2013

A 500MB SOUTHWEST FLOW PREVAILS AT THE BEGINNING OF THE PERIOD WITH
A WEAK SHORT WAVE GENERALLY IDENTIFIED BY THE MODELS MOVING NE
ACROSS THE FA TUESDAY. THIS WILL YIELD THE HIGHEST RAIN CHANCES IN
HIGHER RH AND DYNAMIC FIELDS OVER SOUTHEAST MO VS. FARTHER SE INTO
THE FA. THE SURFACE COLD FRONT`S EASTWARD PROGRESSION ACROSS THE FA
WILL BE SLUGGISH BEFORE IT POSSIBLY BECOMES STATIONARY ACROSS THE FA
IN THE THU/FRI TIME FRAME. THE EXPECTATION IS FOR THE COLD FRONT TO
APPROACH THE WESTERN PART OF THE FA BY WEDNESDAY MORNING AND MOVE
ACROSS MUCH OF THE FA WEDNESDAY/WEDNESDAY NIGHT. THE BOTTOM LINE IS
THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE TUE AND TUE
NIGHT OVER THE WEST/SE MO/SW IL AND TUE NIGHT AND WEDNESDAY NEAR AND
E OF THE MISSISSIPPI RIVER. GIVEN THE SLOW PROGRESSION OF THE
MID/LATE WEEK WEATHER SYSTEM...SOME DECENT...BUT PROBABLY NOT
EXCESSIVE..TOTAL RAINFALL AMOUNTS COULD OCCUR.

REGARDING THE THREAT OF SEVERE THUNDERSTORMS TUESDAY AND
THEREAFTER...THE DYNAMICS AND INSTABILITY WILL POSSIBLY FAVOR
SOME CHANCE OF SEVERE WEATHER IN THE TUESDAY/WEDNESDAY TIME FRAME.
HOWEVER...MORE EXACT TIMING AND MAGNITUDE WILL BE DETERMINED AS
MODEL CONSISTENCY IMPROVES.

A GRADUAL COOLING TREND CAN BE EXPECTED BY THU/FRI WITH COLD AIR
ADVECTION AS SURFACE WINDS BECOME MORE NORTHERLY.

&&

.AVIATION...
ISSUED AT 426 AM CDT SAT MAY 18 2013

IFR VSBYS IN DENSE FOG WILL OCCUR AT KCGI. MVFR CIGS ARE PREVALENT
FURTHER EAST AT KEVV/KOWB AND MAY INCLUDE PERIODS OF LIGHT DRIZZLE
OR MIST REDUCING VSBYS TO MVFR CAT AS WELL. KPAH RESTS BESTWEEN
AND WILL FLUX FROM IFR TO MVFR CIGS. DEPENDING UPON WHERE THE
CLEARING LINE MOVES...VSBYS COULD DETERIORATE IN DEVELOPING FOG AS
WELL. AFTER DAYBREAK CONDITIONS IMPROVE AND VFR RULES SHOULD
DEVELOP BY LATE AM...ALTHOUGH LOW VFR CIGS ARE EXPECTED. SLGT
CHANCE SHOWERS/STORMS IS BEST EAST (KEVV/KOWB) BUT TOO LITTLE TO
MENTION AS A PREVAILING CONDITION AT THE TERMINALS.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR ILZ084-088-
     092-093.

MO...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR MOZ076-086-
     087-100-107>112-114.

IN...NONE.
KY...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KYZ001>004.

&&

$$