National Weather Service Raw Text Product

322 
FXUS63 KTOP 071120
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
620 AM CDT SUN JUL 7 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT SUN JUL 7 2013

MAIN FOCUS FOR THE SHORT TERM IS ON THE SCATTERED SHOWER AND 
ISOLATED THUNDERSTORM POTENTIAL TODAY AS WELL AS LATER TONIGHT. 
EARLY THIS MORNING...RADAR WAS PICKING UP ON SCATTERED 
REFLECTIVITIES ACROSS NORTHEAST AND EAST CENTRAL KANSAS AS THIS 
ACTIVITY WAS BEING SUPPORTED BY SOME WEAK ISENTROPIC LIFT NOTED 
ALONG THE WESTERN EDGE OF THE EXITING MID-LEVEL LOW. HOWEVER...MODEL 
SOUNDINGS SHOWED VERY DRY LOW-LEVEL CONDITIONS WITH REGIONAL 
OBSERVATIONS CONFIRMING CLOUD BASES GENERALLY AROUND 10 KFT WITH 
SOME ISOLATED CLOUD BASES OF 5000FT-7000FT. AS A RESULT...MUCH OF 
THIS EARLY MORNING ACTIVITY EITHER HAS BEEN VIRGA OR BRIEF PERIODS 
OF SPRINKLES BUT THERE WERE A FEW LIGHT RAIN SHOWERS THAT WERE ABLE TO 
DEVELOP WITH THIS ACTIVITY. MODEL SOUNDINGS SHOW SOME ELEVATED 
INSTABILITY PRESENT OVER THE REGION SO THERE HAVE BEEN A FEW RUMBLES 
OF THUNDER THIS MORNING. SHORT RANGE MODELS SHOW THIS SCATTERED 
PRECIPITATION PERSISTING THROUGH THE MORNING HOURS BUT DIMINISHING 
BY EARLY THIS AFTERNOON. IF CONDITIONS REMAIN DRY THIS AFTERNOON AND 
WE ARE ABLE TO GET SOME BREAKS IN THE CLOUD COVER...EXPECT THAT 
TEMPERATURES WOULD QUICKLY BE ON THE RISE WITH HIGHS INTO THE LOW/MID 
90S OVER NORTHEAST AND EAST CENTRAL KANSAS AND POSSIBLY INTO THE 
UPPER 90S OVER NORTH CENTRAL KANSAS. HOWEVER...IF THESE 
SHOWERS/ISOLATED THUNDERSTORMS AND ASSOCIATED CLOUD COVER STICK 
AROUND LONGER INTO THE AFTERNOON...TEMPERATURES WILL BE COOLER THAN 
CURRENTLY FORECASTED. WITH SURFACE HIGH PRESSURE REMAINING ANCHORED 
ACROSS THE EASTERN U.S. AND SURFACE LOW PRESSURE ACROSS WESTERN 
KANSAS...A TIGHT PRESSURE GRADIENT WILL REMAIN IN PLACE OVER THE 
AREA TODAY RESULTING IN BREEZY SOUTHWESTERLY WINDS THAT WILL AID IN 
WARM AIR ADVECTION THIS AFTERNOON. 

A SOMEWHAT ZONAL FLOW HAS SET UP ACROSS THE NORTHERN U.S.  THE 
DEPARTING MID-LEVEL LOW WILL TRACK NORTHEASTWARD TOWARD THE GREAT 
LAKES REGION TODAY...AND ESSENTIALLY GET PULLED INTO THE ZONAL FLOW. 
IN THE MEANTIME...THE MID-LEVEL RIDGE OVER THE SOUTHWESTERN U.S. 
WILL BUILD INTO THE CENTRAL AND SOUTHERN PLAINS TODAY...ULTIMATELY 
BECOMING A BROAD RIDGE EXTENDING ACROSS THE ENTIRE SOUTHERN CONUS BY 
MONDAY. AS THIS RIDGE BUILDS OVER THE AREA...MODELS ARE DETECTING AN 
EMBEDDED WAVE AND ASSOCIATED VORT MAX DEVELOPING OVER NORTHWEST 
KANSAS EARLY THIS EVENING AND SKIMMING THE KANSAS/NEBRASKA BORDER AS 
IT TRACKS TO THE NORTHEAST. AS A RESULT...ADDITIONAL SCATTERED 
SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE TONIGHT THROUGH THE 
OVERNIGHT HOURS ACROSS FAR NORTH CENTRAL AND FAR NORTHEAST KANSAS. 
HOWEVER...MODEL SOUNDINGS ONCE AGAIN SHOW VERY DRY CONDITIONS IN THE 
LOW-LEVELS SO THIS ACTIVITY MAY BE MORE PERIODIC SPRINKLES WITH A 
FEW ISOLATED SHOWERS. WITH SOUTHERLY WINDS REMAINING IN PLACE AND 
INCREASED CLOUD COVER EXPECTED...OVERNIGHT TEMPERATURES WILL BE 
WARMER WITH LOWS LIKELY ONLY DROPPING INTO THE MIDDLE 70S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CDT SUN JUL 7 2013

THE MID/LONG RANGE FORECAST IS FOCUSED ON POTENTIAL FOR
DANGEROUSLY HOT CONDITIONS...PARTICULARLY ON TUESDAY AND NEXT
WEEKEND...AS WELL AS THUNDERSTORM CHANCES PARTICULARLY LATE
TUESDAY INTO WEDNESDAY.

THE UPPER LEVEL RIDGE OVER THE SOUTHWESTERN CONUS WILL BUILD INTO
KANSAS AND OKLAHOMA MONDAY INTO TUESDAY WITH A RATHER IMPRESSIVE
THERMAL RIDGE...28C AND GREATER TEMPS AT 850...FORECAST TO BUILD
INTO NORTHERN KANSAS AND SOUTHERN NEBRASKA. MONDAY SHOULD BE HOT
WITH HIGHS IN THE MIDDLE TO UPPER 90S BUT THERE IS SOME
UNCERTAINTY REGARDING THE AMOUNT OF CLOUD COVER WHICH COULD LIMIT
TEMPS. MOST MODEL GUIDANCE SUGGESTS PASSAGE OF A WEAK VORT MAX ON
MONDAY MORNING WHICH WOULD LEAVE SUBSIDENCE ACROSS THE FORECAST
AREA BY MONDAY AFTERNOON...AND THUS AMPLE SUNSHINE AND HOT TEMPS.
AT THE SAME TIME...AREAS WITH THE HIGHEST TEMPERATURES SHOULD SEE
DRIER DEWPOINTS WITH THE INCREASED BOUNDARY LAYER MIXING. AT THIS
TIME WOULD EXPECT HEAT INDICES TO RANGE FROM THE UPPER 90S TO
103...BUT WOULD ADD 2 TO 3 DEGREES OF WIGGLE ROOM FOR POTENTIAL OF
BOTH CLOUD COVER AND CHANGES IN DEWPOINT.

TUESDAY MAY BE THE HOTTEST DAY OF THE WEEK AS A SURFACE FRONT SETS
UP JUST NORTH OF THE FORECAST AREA WITH THE THERMAL RIDGE AXIS
ORIENTED JUST TO THE SOUTH OF THE FRONT. THIS TYPE OF SITUATION
OFTEN SUGGESTS EXTREME HEAT POTENTIAL NEAR THE THERMAL RIDGE AXIS.
THERE IS AGAIN AT LEAST SOME UNCERTAINTY REGARDING CLOUD POTENTIAL
AS WEAK DISTURBANCES PASS NORTH OF THE FORECAST AREA...BUT FEEL
FAIRLY CONFIDENT IN TEMPERATURES GREATER THAN 100 DEGREES FOR A
GOOD PART OF THE AREA. EXPECT DEWPOINTS TO BE A BIT LOWER YET ON
TUESDAY...BUT THE HEAT INDEX SHOULD STILL BE QUITE HIGH...PROBABLY
IN THE 102 TO 108 RANGE BARRING ANY CLOUD COVER ISSUES.

PRECIPITATION POTENTIAL IS LOW FOR MONDAY AND TUESDAY...WITH ONLY
SLIGHT CHANCES IN NORTHERN KANSAS AS THE WEAK DISTURBANCES PASS
THROUGH AND INTERACT WITH WEAK INSTABILITY ROOTED AROUND 10K FEET.
THUNDERSTORM CHANCES INCREASE BY LATE TUESDAY AFTERNOON INTO
WEDNESDAY MORNING. THIS IS IN RESPONSE TO A STRONG TROUGH FORECAST
TO MOVE INTO THE GREAT LAKES REGION WITH ENERGY IMPACTING THE
LOCAL AREA AS WELL. UNSURE HOW WIDESPREAD THE THUNDERSTORMS WILL
BE...BUT IT APPEARS THAT A 40 TO 50 POP IS WARRANTED GIVEN
CONVERGENCE ALONG THE FRONT AND AT LEAST SOME WEAK UPPER LEVEL
SUPPORT. THERE WILL BE A BIT OF A CAP TO DEAL WITH BUT SHOULD BE
ABLE TO OVERCOME THAT. A FEW STRONG TO SEVERE STORMS APPEAR
POSSIBLE GIVEN STRONG INSTABILITY AND SUBSTANTIAL DEWPOINT
DEPRESSIONS BUT WIND SHEAR SHOULD BE QUITE WEAK AND ORGANIZED
SEVERE WEATHER SEEMS UNLIKELY.

THE FRONT MOVES THROUGH THE AREA BY WEDNESDAY BUT WEAKENS AND
HANGS UP JUST TO THE SOUTH. MEANWHILE...THE UPPER RIDGE WILL BUILD
BACK TO THE NORTHEAST THROUGH THE END OF THE WEAK. WARM ADVECTION
THROUGH THIS PERIOD MAY BE SUFFICIENT WHEN PAIRED WITH WEAK
NORTHWEST FLOW DISTURBANCES TO PRODUCE SOME THUNDERSTORMS...BUT
TIMING AND LOCATION OF THESE CHANCES IS VERY UNCERTAIN AND HAVE
KEPT VERY LOW POPS ACCORDINGLY AT THIS TIME. TEMPERATURES WILL BE
ON THE RISE AFTER THURSDAY...WITH FAIR TO STRONG CONFIDENCE IN
HEAT INDEX READINGS AGAIN CLIMBING ABOVE 100 DEGREES BY THE WEEKEND.

BARJENBRUCH

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 619 AM CDT SUN JUL 7 2013

FOR THE 12Z TAFS...VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WITH 
THE EARLY MORNING SHOWERS TRACKING EAST OF THE AREA THIS 
MORNING...SHOULD SEE MORE SCATTERING OF THE MID-LEVEL CLOUDS THROUGH 
THE DAY. BREEZY SOUTHERLY WINDS ARE EXPECTED BY LATE MORNING THROUGH 
THIS AFTERNOON WITH GUSTS UPWARDS OF 20-25KTS. WILL SEE AN INCREASE 
IN CLOUD COVER OVERNIGHT AS A WEAK WAVE APPROACHES THE REGION. COULD 
SEE SOME SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS DEVELOP WITH 
THIS WAVE...HOWEVER CONFIDENCE IN THIS ACTIVITY OCCURRING NEAR THE 
TAF SITES IS LOW AT THIS TIME SO HAVE KEPT THE TAFS DRY. 

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...HENNECKE
LONG TERM...BARJENBRUCH
AVIATION...HENNECKE