Expires:No;;861584
FXUS63 KTOP 200931
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
431 AM CDT THU JUN 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT THU JUN 20 2013
COMPLICATED FORECAST IN STORE FOR THE AREA ON THURSDAY...MAINLY DUE 
TO CONFLICTING SIGNALS BETWEEN MODEL GUIDANCE AND OBSERVATIONS. 
CURRENTLY ACROSS THE AREA AN AREA OF SURFACE LOW PRESSURE HAS FORMED 
OUT NEAR THE FRONT RANGE...WHICH HAS CAUSED SOUTHERLY FLOW TO 
COMMENCE ACROSS THE AREA. EXPECT THIS FLOW TO INCREASE THROUGH THE 
DAY AS THE PRESSURE GRADIENT TIGHTENS AND MIXING ALLOWS LOW LEVEL 
FLOW TO TRANSLATE TO THE SURFACE. EXPECT THE MID LEVEL RIDGE TO 
BECOME FIRMLY PLANTED OVER THE SOUTHERN PLAINS...WITH THE AMPLIFIED 
APEX OF THE RIDGE AXIS EXTENDING NORTHWARD THROUGH CENTRAL KANSAS 
AND THROUGH THE NORTHERN PLAINS. THE FIRST COMPLICATION IN THIS 
FORECAST...REGARDING POPS FOR THE EARLY MORNING HOURS IS THE FACT 
THAT MOST SHORT TERM HI-RES CONVECTIVE ALLOWING MODELS SHOW 
ELEVATED CONVECTION OCCURRING ACROSS FAR EASTERN KANSAS OVER THE 
NEXT FEW HOURS...HOWEVER CONSIDERING STORMS WOULD LIKELY FIRE 
SHORTLY ACCORDING TO THE MODELS VIRTUALLY NO IR IMAGERY CLOUD 
COOLING IS TAKING PLACE...WHICH WOULD INDICATE THAT CONVECTION IS 
NOT OCCURRING...AT LEAST AS OF YET. FURTHER ENHANCING DOUBT IN THE 
SHORT RANGE MODELS IS THE FACT THAT THEY CURRENTLY INDICATE A WEAK 
MCS OVER NW OKLAHOMA...WHICH CURRENTLY DOES NOT EXIST. IR IMAGERY 
IN FACT SHOWS CLOUD TOP WARMING INSTEAD OF COOLING INDICATIVE OF 
CONVECTIVE PROCESSES OCCURING. WILL CONTINUE TO MONITOR THE TRENDS 
OVER THE NEXT COUPLE OF HOURS TO DETERMINE IF THE MORNING CONVECTION 
WILL TAKE PLACE OVER THE EASTERN HALF OF THE FORECAST AREA. 
THE FOCUS THEN TURNS TO THE AFTERNOON AND ANY CONVECTIVE CHANCES FOR 
THAT TIME PERIOD. AGAIN...CONFLICTING SIGNALS MAKE THIS FORECAST 
DIFFICULT...NAMELY THE FACT THAT NAM AND GFS BREAK OUT CONVECTION 
LATER THIS AFTERNOON WITHIN THE DEEP WARM SECTOR. HOWEVER...MODEL 
SOUNDINGS TAKEN ACROSS THE AREA FOR THIS WEEKEND ARE NOT SUPPORTIVE 
OF CONVECTION OCCURRING...AS A LAYER OF WARM AIR AT 850 TO 700 MB 
BECOMES IN PLACE OVER THE AREA THIS AFTERNOON. REGARDLESS OF THIS 
SIGNAL NAM/GFS INDICATE SOME AFTERNOON CONVECTION TAKING PLACE OVER 
THE AREA...WHICH IN THE ABSENCE OF STRONG MID LEVEL SUPPORT OR ANY 
REAL LOW LEVEL CONVERGENCE SEEMS UNLIKELY TO OCCUR. THE ONE CAVEAT 
TO THIS IS THAT LOW LEVEL BOUNDARIES...WHICH CURRENTLY DO NOT EXIST 
MAY INFLUENCE AFTERNOON CONVECTION. SHOULD MORNING CONVECTION TAKE 
PLACE IN THE AREA...IT COULD ENHANCE LOW LEVEL LIFT BY CREATING AN 
OUTFLOW...WHICH MAY BRING STORMS LATER THIS AFTERNOON. CONSIDERING 
THE SIGNALS IN PLACE RIGHT NOW...WILL OPT FOR A DRY AFTERNOON 
FORECAST...BUT THE DAY SHIFT WILL NEED TO MONITOR AND ADJUST SHOULD 
IT BECOME CLEARER THAT CONVECTION MAY OCCUR.    
JL
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 423 AM CDT THU JUN 20 2013
A LONGER WAVE LENGTH UPPER LEVEL TROUGH WILL REMAIN ACROSS THE WEST 
CENTRAL CONUS THROUGH SATURDAY NIGHT. A DOWNSTREAM UPPER LEVEL RIDGE 
WILL AMPLIFY ACROSS THE SOUTHERN AND CENTRAL PLAINS FRIDAY...AND 
THEN SLOWLY SHIFT EASTWARD INTO THE MID MS RIVER VALLEY BY SATURDAY 
EVENING. THE LONGER WAVE LENGTH THROUGH WILL THEN RETROGRADE WESTWARD 
ACROSS THE PACIFIC NORTHWEST AND THE UPPER RIDGE AXIS WILL EXPAND 
WESTWARD ACROSS THE PLAINS INTO EARLY NEXT WEEK.
FRIDAY THROUGH WEDNESDAY...EXPECT HOT AND HUMID CONDITIONS. 
AFTERNOON AND EVENING THUNDERSTORMS WILL DEVELOP ACROSS THE CENTRAL 
AND NORTHERN HIGH PLAINS AND MOVE NORTHEAST ACROSS THE NORTHERN AND 
CENTRAL PLAINS...WEST AND NORTH OF THE CWA.
AN UPPER LEVEL SHORT-WAVE TROUGH WILL LIFT NORTHEAST ACROSS THE  
NORTHERN PLAINS INTO THE NORTHERN GREAT LAKES SATURDAY NIGHT THROUGH 
MONDAY NIGHT. THIS MAY CAUSE A SLIGHT WEAKNESS TO THE UPPER RIDGE 
AXIS AND MAY ALLOW ISOLATED THUNDERSTORMS TO DEVELOP SUNDAY 
AFTERNOON AND SUNDAY NIGHT...THOUGH AREAS ALONG AND SOUTH OF I-70 
MAY STAY DRY THROUGH THE PERIOD.
HIGHS WILL BE IN THE MID TO UPPER 90S. THERE MAY BE SLIGHT COOL DOWN 
ON SUNDAY WHEN HIGHS MAY ONLY REACH THE LOWER TO MID 90S. HEAT 
INDICES THROUGH THE PERIOD WILL GENERALLY REACH THE UPPER 90S TO 
AROUND 102 DEGREES DURING THE AFTERNOON HOURS.
GARGAN
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1142 PM CDT WED JUN 19 2013
VFR CONDITIONS STILL EXPECTED THROUGH THE TAF PERIOD. MAIN
UNCERTAINTY REMAINS IN THUNDERSTORM POTENTIAL AND TIMING.
MONITORING POTENTIAL FOR STORMS OVER TAF SITES AS EARLY AS 09Z...
BUT FEEL MOST LIKELY TIME IS AFTER SUNRISE. IF STORMS INDEED
DEVELOP THURSDAY MORNING...WEAK OUTFLOW BOUNDARIES MAY SERVE AS A
FOCUS FOR ISOLATED BUT STRONG AFTERNOON TS...SO KEPT VCTS FOR MUCH
OF THE DAY GIVEN THE PERSISTENT POTENTIAL FOR SCATTERED TS. COULD
ALSO SEE SOUTH WINDS GUST TO 25 KTS OR BETTER DURING DAYLIGHT
HOURS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GARGAN
LONG TERM...JL
AVIATION...BARJENBRUCH