Hail and Damaging Winds in Kansas, April 10, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1236 PM CDT THU APR 10 2008

.DISCUSSION...

...MESOSCALE UPDATE...

17Z SFC ANALYSIS INDCS 990 MB SFC LO NR KSLN. 3-6 MB PRES FALLS
WERE NOTED TO THE NE OF THE LO OVR SE NEB/SRN IA...INDICATING THE
LOW SHLD CONT TO LIFT NEWD INTO THAT GENERAL DIRECTION. SFC WRMFNT
EXTNS EWD FM THE LO THRU EMPORIA TO GARNETT...AND WAS ALSO LIFTING
NWD. CLDS HAVE BEEN SLOW TO CLEAR IN THE WARM SECTOR AS OF
17Z...BUT LATEST VISIBLE IMAGES INDCS SOME BREAKING OF THE CLDS
STARTING TO TAKE PLACE OVR TEH SRN CWA. THIS IS LIKELY TO ALLOW
FOR SOME SURFACE HEATING OVR THE ERN CWA THIS AFTN/EVNG.

SEVERE WEATHER CONCERNS LOOK TO BE BECOMING CLEARER EARLY THIS
AFTN. LO LVL WIND FLOW SOUTH OF THE WARM FNT IS INCREASINGLY SW FM
THE SFC TO H85...AND ALTHOUGH THIS CREATES SIG SPEED
SHEAR...PARTICULARLY IN THE 0 TO 1 KM LAYER...IT WILL ALSO ACTS TO
TAKE MOST OF THE SIG LO LVL MOISTURE TO THE EAST OF THE CWA.
ATTM...WE SEE TWO VERY SMALL CHANCES FOR SEVERE WEATHER.
FIRST...IS WITH THE ADVANCING WARMFNT THROUGH EARLY AFTN...BUT
THIS SEEMS LIMITED BY WEAK MID-LVL LAPSE RATES AND LIMITED
INSTABILITY. THUS ALTHOUGH SOME THUNDER SEEMS LIKELY WITH THE
WRMFNT...SEVERE WEATHER THREAT LOOKS SMALL. SECOND WILL BE WITH
THE ACTUAL COLD FNT LATE THIS AFTN AND INTO THE EVNG HOURS.
NEGATIVE WITH THIS SITUATION IS THAT MOST OF THE LO LVL MOISTURE
WILL HAVE BEEN PUSHED TO THE EAST. NEVERTHELESS...MUCAPE OF
500-750 J/KG WILL EXIST ALNG THE CDFNT LATE THIS AFTN WHICH MAY
ALLOW FOR A SCT LINE OF TSRA TO DVLP. BEST JET LVL WINDS WL HAVE
PUSHED EWD OF THE FA AT THIS TIME...WHICH ACTUALLY LOWERS THE DEEP
LAYER SHEAR AND THUS ORGANIZED TSRA THREAT SEEMS TO BE LIMITED. IF
CONVECTION DOES FORM IN EITHER CASE...SEVERE WEATHER MAY BE LMITED
TO A WIND AND ISOLATED HAIL THREAT GIVEN WEAK LAPSE RATES ALOFT.
UNIDIRECTIONAL LOW LEVEL FLOW PRETTY MUCH TAKES ANY TOR THREAT OUT
OF THE AREA.

BOUSTEAD

&&

.PREV DISCUSSION... /ISSUED 354 AM CDT THU APR 10 2008/

DISCUSSION...
08Z WATER VAPOR SHOWS ANOTHER SHORTWAVE ROTATING THROUGH THE BASE OF
THE UPPER TROUGH AND LIFTING THROUGH THE TX PANHANDLE. THIS IS ALSO
WHERE THE STRONGEST PRESSURE FALLS ARE OCCURRING. A WARM FRONT COULD
BE FOUND FROM NORTH TX STRETCHING NORTHEAST THROUGH SOUTHEAST OK AND
INTO NORTHERN AR.

SHOWERS AND THUNDERSTORMS WILL CONTINUE TO SPREAD NORTH DURING THE
PRE DAWN HOURS AS THE SHORTWAVE LIFTS NORTHEAST. THIS SHOULD MAINLY
BE SHOWERS WITH EMBEDDED THUNDERSTORMS. THE SMALL WINDOW FOR SEVERE
WEATHER IS STILL EXPECTED TO BE FROM ABOUT 17Z TO 23Z AS SFC LOW
TRACKS ACROSS THE FORECAST AREA /RUFFLY ACROSS MHK/. WITH THE DRY
SLOT WORKING IN...SOME CLEARING AND DESTABILIZATION IS ANTICIPATED
TO OCCUR AHEAD OF THE COLD FRONT...JUST AS MID LEVEL LAPSE RATES
STEEPEN AND THE LEFT EXIT REGION OF THE UPPER JET MOVES OVER EAST
CENTRAL KS. THINK THUNDERSTORM DEVELOPMENT IS LIKELY TO OCCUR JUST
TO THE WEST OF THE TURNPIKE...WITH THE GREATEST THREAT FOR SEVERE
WEATHER ALONG AND EAST OF THE TURNPIKE. WITH THE CLOSE LOW
OVERHEAD...WILL NEED TO WATCH OUT FOR LOW TOP SUPERCELLS WITH LARGE
HAIL AND AN ISOLATED TORNADO POSSIBLE. ADDITIONALLY WITH THE
CLEARING AND SFC LOW DEEPENING...THINK STRONGER WINDS WILL BE ABLE
TO MIX DOWN TO THE SFC ACROSS THE FAR SOUTHEASTERN SECTION OF THE
FORECAST AREA. THEREFORE WILL ISSUE A WIND ADVISORY FOR COFFEY AND
ANDERSON COUNTIES. ALSO WITH THE REDEVELOPMENT OF THUNDERSTORMS
LIKELY THIS AFTERNOON...DID NOT FEEL COMFORTABLE LETTING THE FLOOD
WATCH EXPIRE AT 18Z...SO WILL EXTEND THE WATCH UNTIL 6 PM AS WELL.

FOR TONIGHT TWEAKED POPS UP TO BETTER MATCH SURROUNDING OFFICES.
LOOKS LIKE THERE COULD BE A DEFORMATION BAND STILL LINGERING OVER
NORTH CENTRAL KS EARLY THIS EVENING. THEN OF COURSE ANY CONVECTION
EXITING TO THE EAST OVER FAR EASTERN KS. POPS FOR FRIDAY THOUGH
SATURDAY ARE MAINLY FOR INSTABILITY DRIVEN SHOWER ACTIVITY. MODELS
CONTINUE TO SHOW THE POSSIBILITY FOR SOME SNOW TO MIX IN ACROSS THE
NORTH TONIGHT. THEN AS LOW LEVEL LAPSE RATES BECOME NEARLY DRY
ADIABATIC FRIDAY AND SATURDAY...THERE COULD BE SOME LIGHT FLURRIES
OR SPRINKLES WITH THE MOISTURE ON THE BACK SIDE OF THE STORM SYSTEM.
ADJUSTED TEMPS DOW A COUPLE DEGREES FOR FRIDAY. LATEST MODEL PROGS
SHOW MIXING 800 TEMPS TO THE SFC WOULD YIELD MID 40S...AND FORECAST
SOUNDINGS KEEP SFC TEMPS IN THE LOWER TO MID 40S FOR FRIDAY. WITH
CLOUDY SKIES AND STRONG MIXING OF THE BOUNDARY LAYER DUE TO GRADIENT
WINDS...WOULD EXPECT MIN TEMPS TO HOLD IN THE MID 30S TONIGHT AND
SATURDAY MORNING. THERE IS SOME CONCERN FOR A HARD FREEZE SUNDAY
MORNING AS SKIES FINALLY CLEAR OUT AND WINDS DIMINISH. HOWEVER
BOUNDARY LAYER WINDS DO NOT COMPLETELY FALL OFF. FORECAST HAS MINS
AT FREEZING. IF WINDS DECOUPLE...TEMPS COULD BE A FEW DEGREES COLDER
SUNDAY MORNING.

AFTER SATURDAY...MODELS SHOW RIDGING DEVELOPING OVER THE PLAINS.
THIS WOULD INDICATE A MODERATION IN TEMPS WITH A DRY
FORECAST...WHICH IS REFLECTED WELL IN THE PREVIOUS FORECAST.
THEREFORE NO CHANGES WERE MADE.

WOLTERS

AVIATION...
BRIEF LULL IN PRECIPITATION EARLY THIS MORNING...ALTHOUGH CIGS
REMAIN IFR AT TOP/FOE...AND BORDERLINE LIFR AT MHK. NEXT BATCH OF
PRECIP TO LIFT NORTHWARD THROUGH THE MORNING. CIGS TO REMAIN
IFR/LIFR THROUGH APPROXIMATELY 18Z...WHEN DRY SLOT AND SUBSIDENCE
BEHIND INITIAL CONVECTION OVERRUN NE KS...SOUTH OF SFC WARM FRONT.
CIGS WILL SCATTER OUT DURING THE EARLY AFTERNOON...AND SOUTHERLY SFC
WINDS WILL PICK UP WITH GOOD MIXING.  CONVECTION MAY REFIRE ALONG
SFC COLD FRONT AS IT SLIDES EASTWARD LATE THIS AFTERNOON...PROMPTING
INCLUSION OF VCTS AT TOP/FOE...WITH BETTER CHANCE FOR CONVECTION
OVER EASTERN PORTIONS OF THE REGION. MVFR CIGS AND NORTHWESTERLY
WINDS PREVAIL ON THE BACKSIDE OF THE SYSTEM AFTER 03Z...AND WILL
PERSIST THROUGH THE END OF THE 12Z TAF CYCLE.

LUNDE

&&

.TOP WATCHES/WARNINGS/ADVISORIES...

WIND ADVISORY UNTIL 6 PM THURSDAY FOR KSZ058-KSZ059.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
243 PM CDT THU APR 10 2008

KSZ008>012-020>024-026-034>040-054>056-058-059-111945-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
243 PM CDT THU APR 10 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL...NORTH
CENTRAL AND NORTHEAST KANSAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL DEVELOP ALONG AND EAST OF A SENECA TO
BURLINGTON LINE THIS AFTERNOON. SOME OF THESE STORMS MAY BE SEVERE
WITH ONE INCH HAIL AND 60 MPH WINDS PRESENTING THE PRIMARY
THUNDERSTORM HAZARDS. THUNDERSTORM ACTIVITY IS EXPECTED TO MOVE
EAST INTO MISSOURI LATE THIS AFTERNOON OR EVENING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS WILL BE NEEDED FOR THE REMAINDER OF THE AFTERNOON
GENERALLY ALONG AND EAST OF A SENECA TO BURLINGTON LINE.

CAVANAUGH