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000
FXUS63 KTOP 180025
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
725 PM CDT FRI MAY 17 2013

.UPDATE...
ISSUED AT 725 PM CDT FRI MAY 17 2013

WITH THE LATEST RAP AND NAM MODELS SHOWING THE STRATUS REMAINING
MAINLY TO THE SOUTHWEST OF THE FORECAST AREA LATE TONIGHT...AM A
LITTLE CONCERNED FOR SOME GROUND FOG FORMATION BETWEEN 08 AND 10Z
THINKING WINDS WILL BE LESS THAN 5 KTS AND SKIES MOSTLY CLEAR.
DEWPOINT TEMPS ACROSS SOUTHERN MO IN THE LOWER 60S AND A
PERSISTENT SOUTHEAST WIND SUGGEST DEWPOINTS ARE MOT LIKELY TO DROP
OFF MUCH TONIGHT. BECAUSE OF THIS HAVE INSERTED A MENTION OF
PATCHY FOG FOR LATE TONIGHT AND EARLY SATURDAY MORNING.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 342 PM CDT FRI MAY 17 2013

SCATTERED TO BROKEN STRATOCU DECK ACROSS THE EASTERN 2/3 OF THE
COUNTY WARNING AREA WILL GRADUALLY DECREASE AFT PEAK
HEATING...BEFORE REDEVELOPING/THICKENING AGAIN LATER TONIGHT AS
MOIST AXIS LIFTS NORTHWARD TOWARDS THE CWA. WILL KEEP THE FCST DRY
THROUGH TONIGHT...BUT INCREASE CLOUDS LATER AGAIN SOUTHWEST TO
NORTHEAST. ALTHOUGH NOT AS DENSE AS LAST NIGHT...STILL THINK SOME
FOG MAY FORM WITH THE STRATUS LATE...BUT NOT DENSE ENOUGH TO INSERT
INTO GRIDS AT THIS POINT. LOWS SHOULD BE IN THE LOW TO MIDDLE 60S.
EXPECT THIS STRATUS DECK SHOULD THIN AGAIN BY MIDDAY/AFTERNOON
SATURDAY ALLOWING FOR HIGH TEMPS TO WARM INTO THE MIDDLE 80S. MODELS
DIFFER ON WHETHER CAPPING INVERSION BY MIDDAY/AFTERNOON CAN BE
OVERCOME ENOUGH FOR SOME SCT CONVECTION TO DEVELOP AS A WEAK WAVE
APPROACHES FROM THE SOUTHWEST. HOWEVER...WITH A STRENGTHENING
ELEVATED MIXED LAYER WITH LITTLE IN THE WAY OF FORCING IN THAT
LAYER...FEEL THE MODELS MAY BE UNDER DOING CINH AND HAVE DECIDED TO
CONTINUE WITH A DRY FCST...OR MORE IN LINE WITH THE EC MODEL.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 342 PM CDT FRI MAY 17 2013

MODELS CONTINUE TO SIGNAL FOR SOME CONVECTION TO DEVELOP ABOVE THE
CAPPING INVERSION SATURDAY NIGHT AS THE LOW LEVEL JET INCREASES AS
WELL AS ISENTROPIC LIFT. WITH NOT HIGH CONFIDENCE WILL CONTINUE TO
KEEP POPS AROUND 20 PERCENT.

BY 12Z SUNDAY THE UPPER TROUGH AXIS WILL MOVE TO NEAR THE WESTERN
KANSAS BORDER. THE SURFACE LOW WILL CONTINUE TO DEEPEN IN WESTERN
KANSAS. SOME ELEVATED STORMS ARE POSSIBLE SUNDAY MORNING FROM ANY
OVERNIGHT DEVELOPMENT. THE UPPER TROUGH WILL MOVE OUT INTO THE
PLAINS SUNDAY TAKING ON A NEGATIVE TILT. THE TROUGH AXIS LOOKS TO
PASS TO THE EAST OF THE CWA SUNDAY NIGHT. ZERO TO 6 KM SHEAR OF 30
TO 40 KTS...1500-2500 J/KG OF ML CAPE ALONG WITH ABUNDANT MOISTURE
IN THE WARM SECTOR. LAPSE RATES STEEPEN AS THE UPPER TROUGH PIVOTS
NORTHEAST AND ERODES THE CAPPING INVERSION. WILL CONTINUE WITH
LIKELY CHANCES OF THUNDERSTORMS IN THE EASTERN 2/3RDS OF THE CWA ON
SUNDAY AFTERNOON WITH THE HIGHER POPS OVER EAST CENTRAL KANSAS
SUNDAY EVENING. GIVEN SHEAR AND INSTABILITY WITH ABUNDANT MOISTURE
STRONG TO SEVERE STORMS ARE POSSIBLE WITH LARGE HAIL AND DAMAGING
WINDS THE MAIN THREAT. THE TORNADO THREAT REMAINS SUNDAY AND SUNDAY
EVENING...ALTHOUGH NOT MUCH CURVATURE TO THE HODOGRAPHS AND TURNING
IN THE FORECAST HODOGRAPHS CANNOT RULE OUT ANY WITH SUPERCELLS.

MONDAY IS STILL A LITTLE BIT OF A QUESTION MARK AS TO HOW FAR
SOUTHEAST THE BOUNDARY WILL SET UP ACROSS EAST CENTRAL KANSAS SO
WILL CONTINUE TO KEEP THE HIGHER THUNDERSTORM CHANCES IN THE
SOUTHEAST CWA. STRONG TO SEVERE STORMS WILL AGAIN BE POSSIBLE MONDAY
AFTERNOON AND EVENING. THE UPPER LOW CONTINUE TO SPIN OVER THE
CENTRAL PLAINS THROUGH WEDNESDAY. THIS WILL KEEP SMALL CHANCES OF
SHOWERS AND THUNDERSTORMS TUESDAY THROUGH EARLY THURSDAY. A RIDGE
BUILDS OVER THE PLAINS LATE THURSDAY AND FRIDAY BRINGING AN END TO
THE PRECIPITATION CHANCES. FROM MONDAY THROUGH FRIDAY TEMPERATURES
WILL BE IN THE 70S FOR HIGHS AND 50S FOR LOWS.


&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 623 PM CDT FRI MAY 17 2013

MODELS SHOW THE BOUNDARY LAYER REMAINING CAPPED WITH RAISING MID
LEVEL HEIGHTS OVERNIGHT. SO THERE SHOULD BE NO CHANCE FOR PRECIP.
THINK FOG FORMATION IS PROBABLE DURING THE PREDAWN HOURS.
CLEARING SKIES AND LIGHT WINDS SHOULD ALLOW THE BOUNDARY LAYER TO
COOL NEAR THE DEWPOINT TEMP BEFORE THE STRATUS HAS A CHANCE TO
MOVE INTO THE TERMINALS. AND WITH DEWPOINTS UPSTREAM IN THE LOWER
60S...DO NOT EXPECT MUCH DRYING IN THE BOUNDARY LAYER. THEREFORE
HAVE INCLUDED SOME IFR VSBY RESTRICTIONS BETWEEN 10Z AND 14Z. THE
BOUNDARY LAYER IS EXPECTED TO BECOME MORE MIXED BY 14Z ALLOWING
CONDITIONS TO GRADUALLY IMPROVE THROUGH THE AFTERNOON SATURDAY.


&&

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

$$

UPDATE...WOLTERS
SHORT TERM...63
LONG TERM...53
AVIATION...WOLTERS