000  
FXUS63 KTOP 211721  
AFDTOP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TOPEKA KS  
1221 PM CDT SAT SEP 21 2019  
   
..AVIATION UPDATE
 
 
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 325 AM CDT SAT SEP 21 2019  
 
EARLY THIS MORNING THE UPPER TROUGH WAS LOCATED FROM MONTANA INTO  
ARIZONA WITH A SOUTHWESTERLY UPPER FLOW PRESENT ACROSS THE PLAINS  
AND A RIDGE OVER THE GREAT LAKES. WATER VAPOR SATELLITE SHOWS A  
STREAM OF MOISTURE FROM EASTERN KANSAS SOUTHWEST INTO THE EASTERN  
PACIFIC THIS MORNING. PRECIPITABLE WATER VALUES WERE GENERALLY  
AROUND TWO INCHES ACROSS EASTERN KANSAS THIS MORNING WHICH IS  
ROUGHLY 200 PERCENT OF NORMAL FOR THIS TIME OF THE MONTH. A COLD  
FRONT EXTENDED FROM THE DAKOTAS TO LOW PRESSURE IN EASTERN COLORADO.  
 
FOR TODAY, SEVERE WEATHER CONTINUES TO BE A POSSIBILITY ESPECIALLY  
IF THE CLOUDS ARE ABLE TO BREAKUP IN THE AFTERNOON HOURS ALLOWING  
FOR FURTHER DESTABILIZATION. FOR AREAS SOUTH OF THE FRONTAL BOUNDARY  
AROUND 2500 TO 3500 J/KG OF MLCAPE IS FORECAST BY MID TO LATE  
AFTERNOON. RUC FORECAST SOUNDINGS SHOW AN EML ACROSS EAST CENTRAL  
KANSAS WHICH ERODES BY LATE AFTERNOON. EXPECT ELEVATED SHOWERS  
THROUGH PART OF THE MORNING WITHIN AN AREA OF ISENTROPIC LIFT.  
PROFILERS SUGGEST THE PRESENCE OF WEAK PV ANOMALIES MOVING NORTHEAST  
WITHIN THE SOUTHWEST FLOW AS WELL. MODELS ARE IN AGREEMENT FOR  
CONVECTIVE DEVELOPMENT DURING THE LATE AFTERNOON AND EARLY EVENING  
HOURS ALONG AND AHEAD OF THE COLD FRONTAL BOUNDARY. SOME DISCRETE  
STORMS ARE POSSIBLE AHEAD OF THE FRONT WHERE SHEAR OF 35 TO 45 KTS  
IS FORECAST. HODOGRAPHS SUPPORT THE POSSIBILITY OF A TORNADO WITH  
HELICITY VALUES AROUND 200 M2/S2. STRONG MID LEVEL SHEAR AND  
STEEPENING LAPSE RATES WILL FAVOR LARGE HAIL FORMATION IN THE  
AFTERNOON AND EVENING HOURS. STORMS SHOULD CONSOLIDATE DURING THE  
EVENING HOURS AND PROGRESS SOUTHEAST THROUGH THE OVERNIGHT HOURS  
INTO SUNDAY.  
 
FORCING FOR ASCENT WILL INCREASE OVERNIGHT WITH THE APPROACHING MID  
LEVEL TROUGH. STRONG MOISTURE TRANSPORT IS FORECAST AHEAD OF THE  
TROUGH INTO EASTERN KANSAS. 925 MB TO 850 MB MOISTURE CONVERGENCE  
WILL INCREASE DURING THE EVENING AND OVERNIGHT HOURS WITH THE  
BACKING OF THE LOW LEVEL JET. UPPER LEVEL DIVERGENCE IS FORECAST TO  
INCREASE ACROSS NORTHEAST AND EAST CENTRAL KANSAS WITHIN THE AREA OF  
THE ENTRANCE REGION OF THE UPPER JET. TRAINING OF CELLS WILL LEAD TO  
HEAVY RAINFALL IN THE 2 TO 4 INCH RANGE WITH LOCALLY HIGHER AMOUNTS  
APPROACHING 6 INCHES OR HIGHER THROUGH SUNDAY MORNING. THEREFORE  
WILL MAINTAIN THE FLASH FLOOD WATCH THROUGH EARLY SUNDAY  
AFTERNOON.  
   
LONG TERM
 
(SUNDAY THROUGH FRIDAY)  
ISSUED AT 325 AM CDT SAT SEP 21 2019  
 
THE FRONTAL BOUNDARY MOVES SOUTHEAST OF THE FORECAST AREA SUNDAY  
EVENING WITH THE PASSAGE OF THE UPPER TROUGH BRINGING AN END TO THE  
PRECIPITATION IN EAST CENTRAL KANSAS. A DRY PERIOD IS EXPECTED  
MONDAY AND MONDAY NIGHT WITH THE RETURN OF PRECIPITATION CHANCES  
AGAIN ON TUESDAY AS A MID LEVEL WAVE IS FORECAST TO MOVE ACROSS  
NEBRASKA AND KANSAS. TUESDAY NIGHT INTO WEDNESDAY A TROUGH WILL MOVE  
ACROSS THE PLAINS AND BRING ANOTHER FRONTAL BOUNDARY SOUTHEAST INTO  
KANSAS ON WEDNESDAY. MODELS DIFFER WITH THE TIMING AND HANDLING OF  
THE EJECTION OF THE UPPER LOW OVER THE SOUTHWEST STATES INTO THE  
CENTRAL PLAINS. THEREFORE CONFIDENCE IS NOT HIGH AND HAVE MAINTAINED  
SMALL CHANCES OF PRECIPITATION INTO NEXT FRIDAY. HIGH TEMPERATURES  
WILL BE NEAR NORMAL THROUGH THE PERIOD WITH HIGHS IN THE UPPER 70S  
TO AROUND 80.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)  
ISSUED AT 1221 PM CDT SAT SEP 21 2019  
 
MVFR CIGS ARE LIKELY TO PERSIST THROUGH THE AFTERNOON AT TOP AND  
FOE AS LOW LEVEL MOISTURE CONTINUES TO ADVECT NORTHEAST. MHK IS  
EXPECTED TO SEE SOME IMPROVEMENT IN THE CIGS IN THE NEXT SEVERAL  
HOURS. THE LOW CLOUDS ARE EXPECTED TO EVENTUALLY LIFT BY THIS  
EVENING AS TS DEVELOPMENT FOCUSES ALONG THE FRONTAL BOUNDARY  
ACROSS NORTH CENTRAL KS. TS ARE MOST LIKELY TO IMPACT THE  
TERMINALS OVERNIGHT AND SUNDAY MORNING. TIMING TS WILL BE THE MAIN  
CHALLENGE WITH THE FORECAST.  
 

 
   
TOP WATCHES/WARNINGS/ADVISORIES
 
 
FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH SUNDAY  
AFTERNOON FOR KSZ010>012-022>024-026-035>040-054>056-058-059.  
 

 
 

 
 
SHORT TERM...53  
LONG TERM...53  
AVIATION...WOLTERS  
 
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