Hail in Kansas, September 8, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
443 AM CDT MON SEP 8 2008

.DISCUSSION...

SHORT TERM THUNDERSTORM AND HEAVY PRECIPITATION CONCERNS ARE THE
FOCUS OF THE FORECAST PACKAGE.

00Z UPPER AIR ANALYSIS INDICATED A SHORTWAVE TROUGH MOVING
NORTHEAST INTO THE CENTRAL PLAINS FROM NM AND ANOTHER STRONGER
SHORTWAVE TROUGH MOVING SOUTHEAST INTO THE NORTHERN PLAINS FROM
THE NORTHERN CONUS ROCKIES. H850 ANALYSIS INDICATED WARM FRONT
DRAPED FROM ROUGHLY NORTHWESTERN KS SOUTHEAST INTO SOUTHEASTERN
KS. CONVECTION WAS ALREADY WIDESPREAD THROUGH THE CWA...WITH THE
MOST INTENSE CONVECTION ALIGNED NEAR INTERSTATE 70 AT FORECAST
TIME.

MODELS INDICATE THAT WARM FRONT/LOW LVL BAROCLINIC ZONE WILL SWING
NORTHWEST THIS MORNING IN RESPONSE TO CYCLOGENESIS OVER SOUTHWESTERN
KS BISECTING THE TOPEKA CWA ALONG A SOUTHWEST TO NORTHEAST LINE.
MODELS INDICATE THAT AREAS ROUGHLY ALONG AND SOUTHEAST OF
INTERSTATE 35 WILL REMAIN IN THE WARM SECTOR WHILE AREAS TO THE
NORTH WILL REMAIN BEHIND THE BOUNDARY. LOW LEVEL JET OF AROUND 40
KTS WAS IMPINGING UPON THIS BOUNDARY PER SOUTH CENTRAL KS WIND
PROFILERS. AS STRONG SHORTWAVE TROUGH TRANSLATES EAST THROUGH THE
NORTHERN PLAINS...AND THE SOUTHWESTERN CONUS TROUGH MOVES
NORTHEAST TOWARDS KS...WOULD EXPECT CONTINUED DEVELOPMENT OF
CONVECTION WITH FAVORABLE LARGE SCALE ASCENT...GOOD LOW LEVEL
FRONTOGENETIC FORCING ALONG AND NORTHWEST OF THE BAROCLINIC ZONE
AND STRONG LOW LVL MOISTURE CONVERGENCE. INSTABILITY LOOKS
SOMEWHAT UNDERESTIMATED BY SPC RUC ANALYSIS WITH A FEW TSTMS THAT
LOOK MORE ORGANIZED THAN ANTICIPATED GIVEN MUCAPE ESTIMATE OF 500
J/KG OR LESS. CANNOT RULE OUT A MARGINALLY SEVERE THUNDERSTORM
DURING THE MORNING HOURS BUT THINK THAT THE PRIMARY HAZARD IN
GENERAL ASSOCIATED WITH CONVECTION TODAY WILL BE HEAVY RAINFALL
WHICH COULD LEAD TO SOME LOCALIZED FLOODING. PRECIPITABLE WATER
VALUES OF 1.5 TO 1.75 INCHES WILL REMAIN OVER THE CWA
TODAY...ALLOWING FOR THE POTENTIAL FOR RAINFALL RATES IN EXCESS OF
ONE INCH PER HOUR. OTHER SEVERE WEATHER HAZARDS WOULD BE ISOLATED
INSTANCES OF QUARTER SIZE HAIL AND 60 MPH OUTFLOW WINDS.

AS SHORTWAVE TROUGH MOVES EAST THROUGH THE NORTHERN
PLAINS...BAROCLINIC ZONE WILL SLIDE SOUTHEAST DROPPING
TEMPERATURES QUICKLY. INCLUDED NON DIURNAL TEMPERATURE TREND FOR
FALLING TEMPERATURES ACROSS THE CWA THIS AFTERNOON. SUBSIDENCE
BEHIND THE SHORTWAVE TROUGH...AND ISENTROPIC DOWNGLIDE BEHIND THE
COLD FRONT SHOULD EFFECTIVELY END PRECIPITATION CHANCES AFTER
SUNSET IN THE TOPEKA CWA.

EXTENDED...NO SIGNIFICANT CHANGES MADE WITH FOCUS ON SHORT TERM FORECAST.

CAVANAUGH

&&

.AVIATION...

LATEST PROFILER NETWORK ACRS KS INDCG LO LVL JET INCREASING AS
EXPECTED. IN RESPONSE TO THIS INCREASED FORCING...ISO WEAK TSRA
HAVE BEGAN TO DVLP OVR CNTRL KS. EFFECTIVE INFLOW BASE IS LOWER
THAN THE ACTIVITY EARLIER TONIGHT AND APPEAR TO BE ROOTED AROUND
H8. THUS A LITTLE BETTER INSTABILITY IS AVAILABLE FOR THIS NEW
ACTIVITY AND WOULD EXPECTED TSRA TO EXPAND IN COVERAGE AND
INTENSITY THRU A GOOD PART OF THE NIGHT. GIVEN UPSTRM SOUNDINGS FM
KDDC/KOUN...FEEL THE SVR WX THREAT IS PRETTY LIMITED OVERNIGHT
GIVEN THE DEPTH OF THE LO LVL MOISTURE ARND H85 AND THE LAPSE
RATES ABOVE. NEVERTHELESS A STRONG STORM IN THE NW CANNOT BE RULED
OUT. ONLY OTHER CHANGES THIS EVNG WERE TO CONT TO LOWER POPS IN
THE SE AND ADD SOME ADDITIONAL TIMING TO THE POPS IN THE NW. WE
SHLD SEE THE BULK OF THE PRECIP IN THE AREA AFTER 09Z. ONLY OTHER
CHANGE WAS TO LOWER GOING HIGHS FOR MON OVR THE NW WHERE STG
CAA/RA AND CLDS WILL MAKE FOR A VERY CHILLY DAY FOR EARLY SEP.

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
849 PM CDT SUN SEP 7 2008

KSZ008>012-020>024-026-034>040-054>056-058-059-081500-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
849 PM CDT SUN SEP 7 2008

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

.DAY ONE...TONIGHT

THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS TONIGHT. THE MAIN
THREAT AREA IS NORTH AND WEST OF A LINE FROM COUNCIL GROVE TO
HIAWATHA. THE MOST LIKELY TIME FOR ISOLATED SEVERE WEATHER WILL BE
AFTER MIDNIGHT THROUGH 5 AM. THE MAIN THREAT FROM THUNDERSTORMS
WOULD BE LARGE HAIL.

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP TONIGHT ACROSS
NORTH CENTRAL KANSAS AND SPREAD NORTH AND EAST ACROSS THE OUTLOOK
AREA. DUE TO FAVORABLE SHEAR AND INSTABILITY ACROSS NORTH CENTRAL
KANSAS...AND ISOLATED SEVERE STORM IS POSSIBLE. LARGE HAIL UP TO
THE SIZE OF QUARTERS WOULD BE THE MAIN THREAT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A COLD FRONT WILL PUSH ACROSS THE REGION DURING THE DAY MONDAY.
THUNDERSTORMS ARE POSSIBLE ACROSS THE ENTIRE OUTLOOK AREA. SOME OF
THE STORMS MAY BE SEVERE DURING THE AFTERNOON HOURS ACROSS EAST
CENTRAL KANSAS WHERE BETTER INSTABILITY WILL BE AVAILABLE.

ANOTHER COLD FRONT WILL APPROACH THE AREA BEGINNING LATE TUESDAY
NIGHT. THERE IS A CHANCE FOR THUNDERSTORMS WEDNESDAY AND THURSDAY
ACROSS THE ENTIRE OUTLOOK AREA AS THE FRONT PUSHES THROUGH. THE
FRONT WILL THEN LIFT BACK NORTHWARD TOWARD THE END OF THE WORK
WEEK...AND BRING ANOTHER CHANCE FOR THUNDERSTORMS FRIDAY NIGHT AND
SATURDAY MAINLY ACROSS PORTIONS OF EAST CENTRAL KANSAS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TONIGHT...BUT SPOTTERS ARE
ENCOURAGED TO REPORT HAIL A HALF INCH OR GREATER IN SIZE.

BOUSTEAD

SIGNIFICANT WEATHER ALERT
NATIONAL WEATHER SERVICE TOPEKA KS
305 AM CDT MON SEP 8 2008

KSZ035-036-080830-
DICKINSON-GEARY-
305 AM CDT MON SEP 8 2008

THROUGH 330 AM CDT...A CLUSTER OF THUNDERSTORMS WILL MOVE NORTHEAST
AT 30 MPH ACROSS NORTHERN DICKINSON AND EASTERN GEARY COUNTIES.  AS
THESE STORMS PASS...EXPECT PENNY SIZE HAIL...STRONG WINDS OF 40 TO
50 MPH AND TORRENTIAL RAINFALL. SOME LOCATIONS THAT COULD BE
AFFECTED INCLUDE MILFORD STATE PARK...JUNCTION CITY...CHAPMAN AND
GRANDVIEW PLAZA. MOTORISTS ALONG INTERSTATE 70 BETWEEN MILE MARKERS
290 AND 301 COULD ALSO BE AFFECTED.

SIGNIFICANT WEATHER ALERT
NATIONAL WEATHER SERVICE TOPEKA KS
331 AM CDT MON SEP 8 2008

KSZ038-039-055-080900-
OSAGE-SHAWNEE-WABAUNSEE-
331 AM CDT MON SEP 8 2008

THROUGH 400 AM CDT...A CLUSTER OF THUNDERSTORMS WILL MOVE NORTHEAST
AT 30 MPH ACROSS SOUTHERN WABAUNSEE...NORTHWEST OSAGE AND SOUTHWEST
SHAWNEE COUNTIES. NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THIS CLUSTER OF STORMS IS CAPABLE OF PRODUCING PENNY SIZE
HAIL...STRONG WINDS OF 40 TO 50 MPH AND TORRENTIAL RAINFALL. SOME
LOCATIONS THAT COULD BE AFFECTED INCLUDE ESKRIDGE...HARVEYVILLE AND
DOVER. MOTORISTS ALONG THE KANSAS TURNPIKE BETWEEN MILE MARKERS 159
AND 167 COULD ALSO BE AFFECTED.

SIGNIFICANT WEATHER ALERT
NATIONAL WEATHER SERVICE TOPEKA KS
346 AM CDT MON SEP 8 2008

KSZ022-035-036-080915-
DICKINSON-GEARY-RILEY-
346 AM CDT MON SEP 8 2008

THROUGH 415 AM CDT...A CLUSTER OF THUNDERSTORMS WILL MOVE NORTHEAST
AT 30 MPH ACROSS NORTHEAST DICKINSON...GEARY...AND RILEY COUNTIES.
NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THIS CLUSTER OF
STORMS IS CAPABLE OF PRODUCING PENNY SIZE HAIL...STRONG WINDS OF 40
TO 50 MPH AND TORRENTIAL RAINFALL. SOME LOCATIONS THAT COULD BE
AFFECTED INCLUDE GRANDVIEW PLAZA...OGDEN...JUNCTION CITY...KEATS AND
WESTERN MANHATTAN. MOTORISTS ALONG INTERSTATE 70 BETWEEN MILE
MARKERS 290 AND 315 COULD ALSO BE AFFECTED.

SIGNIFICANT WEATHER ALERT
NATIONAL WEATHER SERVICE TOPEKA KS
412 AM CDT MON SEP 8 2008

KSZ022-038-080945-
RILEY-WABAUNSEE-
412 AM CDT MON SEP 8 2008

THROUGH 445 AM CDT...A LINE OF THUNDERSTORMS WILL MOVE EASTWARD
THROUGH NORTHERN WABAUNSEE COUNTY. THIS LINE OF STORMS WILL BRING
WIND GUSTS NEAR 50 MPH AS WELL AS HEAVY DOWNPOURS. NATIONAL WEATHER
SERVICE DOPPLER RADAR INDICATED THIS CLUSTER OF STORMS IS ALSO
CAPABLE OF PRODUCING PENNY SIZE HAIL. SOME LOCATIONS THAT COULD BE
AFFECTED INCLUDE ALMA...MCFARLAND AND PAXICO. MOTORISTS ALONG
INTERSTATE 70 BETWEEN MILE MARKERS 317 AND 340 SHOULD BE PREPARED
FOR SUDDEN HEAVY DOWNPOURS AS WELL AS STRONG WINDS.