928  
FXUS63 KPAH 230719  
AFDPAH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PADUCAH KY  
219 AM CDT SAT JUN 23 2018  
   
.SHORT TERM
 
(TODAY THROUGH MONDAY NIGHT)  
ISSUED AT 219 AM CDT SAT JUN 23 2018  
 
IN THE WAKE OF THE DEPARTED 500MB LOW, WE WILL TRANSITION BRIEFLY  
TO A ZONAL UPPER FLOW, BUT NOT BEFORE THE MCS WORKING INTO  
SOUTHWEST MO AND AR MOVES MORE SOUTHEAST. THE MCS WILL CAUSE  
LITTLE IF ANY IMPACT TO SOUTHEAST MO, THANKS TO THE RESULTANT ESE  
FLOW OF THE DEPARTING UPPER LOW. HOWEVER, SOME RIPPLES IN THE  
500MB FLOW TODAY COULD HELP GENERATE SOME SHOWERS/THUNDERSTORMS  
ACROSS THE SOUTHERN PART OF THE FA, ALTHOUGH MODEL QPF, INCLUDING  
THE HRR, IS KEPT ALMOST ENTIRELY SOUTH INTO AR AND TN. FOR TONIGHT  
AND EARLY SUNDAY, THERE HAS BEEN SOME TREND TOWARD A SOUTHWARD  
SHIFT IN THE SHOWER/THUNDERSTORM ACTIVITY AS WELL. YET THE NGM AND  
ECMWF STILL GENERATE PRECIP ACROSS THE SOUTHERN PART OF THE FA,  
SO WILL KEEP CHANCE POPS THERE CONSIDERING THIS, AND THE CLOSE  
PROXIMITY OF A SURFACE BOUNDARY TO OUR SOUTH ALONG WITH POSSIBLE  
OUTFLOW BOUNDARIES FROM THE GLANCING MCS.  
 
INSTABILITY IS EXPECTED TO BE FAIRLY ROBUST, PEAKING AROUND 1500-  
2000 J/KG MLCAPE ACROSS THE SOUTH LATE THIS AFTERNOON/EARLY THIS  
EVENING AND AVERAGING 1000-1500 J/KG MLCAPE OVERNIGHT WHEN THE  
BETTER THUNDERSTORM CHANCES ARRIVE. THE HIGHER RAIN CHANCES WILL  
AGAIN BE SOUTH. A MARGINAL RISK OF SEVERE STORMS CONTINUES SUNDAY,  
MAINLY ALONG AND EAST OF THE MISSISSIPPI RIVER.  
 
A SURFACE BOUNDARY WILL LIFT NORTHEAST ACROSS THE FA SUNDAY NIGHT  
AND MONDAY KEEPING THE CHANCE OF SHOWERS AND THUNDERSTORMS ALIVE. A  
BRIEF END TO RAIN CHANCES IS FORECAST FOR MONDAY NIGHT, EXCEPT  
ACROSS THE NORTH, AS THE BOUNDARY LIFTS NE OF THE FA AND A 500MB  
HIGH PRESSURE RIDGES TRANSITIONS ACROSS THE FA. A WARMING/INCREASING  
HUMIDITY TREND WILL BEGIN SUNDAY. HEAT INDICES WILL BE IN THE 90S  
SUNDAY AND AROUND 100 MONDAY.  
   
LONG TERM
 
TUESDAY THROUGH FRIDAY  
ISSUED AT 219 AM CDT SAT JUN 23 2018  
 
ON TUESDAY, THE UPPER LEVEL RIDGE THAT WAS IN PLACE AT THE BEGINNING  
OF THE WEEK, WILL SHIFT EASTWARD THROUGHOUT THE DAY, AS AN UPPER  
LEVEL TROUGH PUSHES IN FROM THE WEST. THIS FEATURE WILL PROVIDE  
SUPPORT FOR A GOOD CHANCE FOR CONVECTION WITH THE HIGHEST CHANCES  
ACROSS THE NORTHERN HALF OF THE AREA, CLOSER TO BETTER DYNAMICS.  
 
WHILE THE EVENING HOURS LOOK FAIRLY DRY RIGHT NOW ON TUESDAY, WE  
WILL HAVE TO WATCH HOW THINGS EVOLVE UPSTREAM. MODELS ARE DEVELOPING  
AN MCS TYPE SYSTEM NEAR A SURFACE BOUNDARY IN NORTHERN MISSOURI BY  
00Z AND SLIDE THAT SOUTHEAST DURING THE EVENING AND OVERNIGHT HOURS.  
IT HAS THE BEST CHANCE OF IMPACTING OUR AREA OVERNIGHT TUESDAY INTO  
WEDNESDAY MORNING. WILL KEEP POPS LOW AS CONFIDENCE IN THE  
DEVELOPMENT OF THE MCS AND ITS MOVEMENT/TIMING ARE OBVIOUSLY STILL  
IN QUESTION THIS FAR OUT IN TIME. HOW MUCH CONVECTION WILL BE LEFT  
BY WEDNESDAY AFTERNOON OR ANY POTENTIAL REDEVELOPMENT ON LEFTOVER  
BOUNDARIES IS STILL UNCERTAIN AS WELL. WILL MAINTAIN LOW END POPS TO  
COVER THESE POSSIBILITIES FOR NOW.  
 
UPPER LEVEL HEIGHTS BUILD WEDNESDAY NIGHT INTO THURSDAY AS UPPER  
LEVEL RIDGING TAKES OVER. THIS SHOULD PUT THE LID ON ANY CONVECTION  
ESPECIALLY IN WESTERN PARTS OF THE CWA. HOWEVER, DEPENDING ON HOW  
FAR EAST THE UPPER HIGH MAKES IT, THE EASTERN PERIPHERY OF THE CWA  
COULD SEE CHANCES FOR CONVECTION, ON THE EASTERN SIDE OF THE UPPER  
HIGH. AFTER SEEING HIGHS ON TUESDAY AND WEDNESDAY IN THE LOW 90S,  
READINGS WILL PROBABLY RISE INTO THE MID 90S ACROSS WESTERN PARTS OF  
THE AREA FOR THURSDAY. BY THURSDAY NIGHT INTO FRIDAY, THE UPPER HIGH  
SURE LOOKS LIKE IT BE DOMINATING THE AREA AND ALLOWING FOR ANOTHER  
HOT AND DRY DAY WITH MINIMAL CHANCES FOR PRECIPITATION.  
 
LOOKING AT HEAT INDICES, IT APPEARS AS THOUGH MANY IF NOT MOST AREAS  
WILL BE DEALING WITH HEAT INDICES OF AT LEAST 100 TO 105 DEGREES  
DURING THE EXTENDED FORECAST PERIOD ESPECIALLY AS WE GET TOWARD  
THURSDAY AND FRIDAY.  
 

 
   
AVIATION
 
 
ISSUED AT 219 AM CDT SAT JUN 23 2018  
 
PRIMARILY VFR CONDITIONS ARE ANTICIPATED THROUGH THE FORECAST  
PERIOD. THIS IS SOMEWHAT MORE OPTIMISTIC THAN PREVIOUS FORECAST,  
THOUGH A PERIOD OF MVFR CEILINGS IS STILL POSSIBLE EARLY THIS  
MORNING--PARTICULARLY AT KEVV AND KOWB. PATCHY EARLY MORNING FOG MAY  
ALSO TEMPORARILY REDUCE VISIBILITIES TO MVFR. REMNANTS OF AN MCS  
OVER THE PLAINS MAY BRUSH FAR SOUTHERN PORTIONS OF THE AREA SATURDAY  
MORNING, BUT IS FORECAST TO STAY SOUTH OF THE TAF SITES. WHILE AN  
ISOLATED SHOWER OR THUNDERSTORM CANNOT BE COMPLETELY RULED OUT ON  
SATURDAY, THE PROBABILITY WAS DEEMED TOO LOW TO MENTION IN THE  
FORECAST AT THIS TIME. A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS  
ARRIVES OVERNIGHT TONIGHT/EARLY SUNDAY. SOUTHWEST WINDS WILL REMAIN  
LESS THAN 10 KNOTS THROUGH THE PERIOD.  
 

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

 
 

 
 
SHORT TERM...RLS  
LONG TERM...CW  
AVIATION...RLS  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab KY Page
The Nexlab IL Page
The Nexlab IN Page
The Nexlab MO Page Main Text Page