Tornadoes and Hail in Kansas, April 14 to 15, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1243 PM CDT SAT APR 14 2012

...UPDATE TO AVIATION...

.DISCUSSION...

TODAY/TONIGHT...PRIMARY CONCERN IN FORECAST PACKAGE IS THE NEXT 24
HOURS FOR THE POTENTIAL OF SEVERE WEATHER...WITH THIS DISCUSSION
FOCUSING MORE ON THE ANTICIPATED EVOLUTION AND UNCERTAINTY OF THE
EVENT. AS OF THIS MORNING...TWO MAIN COMPLEXES OF SHOWERS AND
THUNDERSTORMS STRETCHED FROM WEST CENTRAL MISSOURI THROUGH NORTH
CENTRAL OKLAHOMA. EXPECT THESE CLUSTERS TO PERSIST THROUGH SUNRISE
AS THEY MOVE EAST NORTHEAST. THE HIGHEST PROBABILITY FOR
PRECIPITATION CHANCES THIS MORNING WILL RESIDE OVER EAST CENTRAL
KANSAS. WHILE DETAILS DIFFER...SHORT TERM HIGH RESOLUTION MODEL
GUIDANCE SUGGESTS ADDITIONAL ACTIVITY MAY DEVELOP FURTHER WEST OF
THE ONGOING CLUSTER TRAJECTORY. IN FACT...THE DEGREE OF ADDITIONAL
WARM SECTOR CONVECTION BETWEEN 12-18Z COMPLICATES THE DEGREE OF THE
SEVERE WEATHER POTENTIAL ACROSS THE CWA. CURRENT THINKING IS THAT AT
LEAST SCATTERED SHOWERS/THUNDERSTORMS WILL DEVELOP AROUND/AFTER
SUNRISE ACROSS CENTRAL/EASTERN KANSAS. WITH THIS ANTICIPATED CLOUD
COVER/PRECIPITATION...MUCH OF THE CWA MAY TEMPORARILY REMAIN
RELATIVELY STABLE THROUGH MIDDAY. DESTABILIZATION WILL OCCUR DURING
THE AFTERNOON HOURS IN THE WAKE OF MORNING CONVECTION IN ADVANCE OF
A DRYLINE AND APPROACHING STRONG UPPER LEVEL SYSTEM. THE DRYLINE IS
EXPECTED TO BE LOCATED FROM HILL CITY KS TO ELK CITY OK BY MIDDAY
AND WILL GRADUALLY MIX EASTWARD DURING THE AFTERNOON HOURS.
OPERATIONAL GUIDANCE CONTINUES A SHEEPISH TREND WITH REGARDS TO
CONVECTIVE DEVELOPMENT/COVERAGE ALONG THE DRYLINE THROUGH THE LATE
AFTERNOON HOURS IN KANSAS. A FEW ISOLATED STORMS SHOULD DEVELOP
PRIOR/NEAR 00Z ALONG THIS BOUNDARY...AND QUICKLY MOVE NORTHEAST.
THIS INITIAL DEVELOPMENT WILL LIKELY BE SUPERCELLULAR IN NATURE DUE
TO THE VERY SUPPORTIVE ENVIRONMENTAL CONDITIONS (SEE SPC DAY 1) AND
WITH LIMITED COMPETITION FROM SURROUNDING CONVECTION. WITH THE
ANTICIPATED DRYLINE LOCATION AT 00Z...NORTH CENTRAL KANSAS WILL HAVE
THE HIGHEST SEVERE WEATHER THREAT. OVERALL COVERAGE REMAINS IN
QUESTION...AND IT IS CERTAINLY POSSIBLE THAT ONLY ONE OR TWO STORMS
MAY INITIALLY IMPACT PORTIONS OF THE CWA BY EARLY EVENING. AS THE
EVENING...AND ESPECIALLY OVERNIGHT PERIOD PROGRESSES...INCREASED
LINEAR FORCING SHOULD HELP YIELD A BROKEN SQUALL LINE OVER PORTIONS
OF THE CWA AS THE PACIFIC COLD FRONT OVERTAKES THE DRYLINE. IF
SUPERCELL STORMS IN FACT DEVELOP AND MOVE INTO NORTH CENTRAL KANSAS
BY EARLY EVENING...SIGNIFICANT SEVERE WEATHER WILL BE
POSSIBLE...INCLUDING STRONG TORNADOES. AS THE CONVECTION
MOVES/EVOLVES EASTWARD...THE SEVERE WEATHER THREAT WILL
CONTINUE...WITH THE POSSIBILITY FOR EMBEDDED NIGHTTIME TORNADOES
WITHIN THE LINE OF STORMS. AGAIN...THERE ARE STILL SEVERAL VARIABLES
NOT YET RESOLVED THAT COULD EITHER ENHANCE OR LIMIT THE OVERALL
SEVERE WEATHER POTENTIAL LATE THIS AFTERNOON INTO THE OVERNIGHT
HOURS. WITH THIS DYNAMIC OF A SYSTEM...THE POTENTIAL IS CERTAINLY
THERE FOR SUBSTANTIAL SEVERE WEATHER. SIDE NOTE...WIND SPEEDS LOOK
TO STAY NEAR/BELOW WIND ADVISORY CRITERIA TODAY...AND WITH MAIN
CONCERN ON SEVERE WEATHER...WILL NOT ISSUE WIND ADV IN THIS PACKAGE.

SUNDAY/BEYOND...THE FRONT AND ASSOCIATED THUNDERSTORM ACTIVITY WILL
BE LOCATED OVER FAR EASTERN KANSAS BY SUNRISE SUNDAY. MOST
PRECIPITATION WILL EXIT THE CWA BY MIDDAY/EARLY AFTERNOON. AFTER THE
PRIMARY TROUGH PASSAGE ON MONDAY...UPPER PATTERN DEAMPLIFIES WITH
WEAK UPPER DISTURBANCES PROJECTED TO MOVE THROUGH THE
CENTRAL/NORTHERN PLAINS. BOTH THE EURO/GFS ARE IN REASONABLE
AGREEMENT WITH THE PATTERN/TIMING OF A STRONG SHORTWAVE TROUGH
MOVING THROUGH THU INTO FRI...AND LIKEWISE HAVE INSERTED NEXT
THUNDERSTORM MENTION FOR THIS PERIOD.

BLAIR

&&

.AVIATION...

PREVAILING VFR STRATUS WITH OCCASIONAL MVFR CONDITIONS FOR THE
NEXT FEW HOURS. ISOLATED STRONG TO SEVERE THUNDERSTORMS ARE
EXPECTED TO BE IN THE VICINITY OF TERMINALS FOR MUCH OF THE
AFTERNOON AND EVENING HOURS. AMENDMENTS WILL BE MADE BASED ON
TIMING AND LOCATION OF THUNDERSTORM DEVELOPMENT. IN
ADDITION...VERY STRONG SOUTH WINDS AHEAD OF A TIGHTENING SURFACE
LOW ARE EXPECTED TO INCREASE SUNDAY MORNING WITH GUSTS NEAR 36 KTS AT
TERMINALS. EXPECT THE THUNDERSTORM ACTIVITY TO END NEAR THE 13Z TO
15Z TIME FRAME.

BOWEN

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
1111 AM CDT SAT APR 14 2012

KSZ008>012-020>024-026-034>040-054>056-058-059-151615-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
1111 AM CDT SAT APR 14 2012

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

.DAY ONE...TODAY AND TONIGHT.

SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF A
DRYLINE IN CENTRAL KANSAS BY THE AFTERNOON PERIOD. THESE STORMS WILL
MOVE NORTHEASTWARD TOWARDS NORTH CENTRAL KANSAS DURING THE EVENING
HOURS. STORMS THAT CAN REMAIN ISOLATED WILL HAVE THE POTENTIAL TO
PRODUCE VERY LARGE HAIL UP TO BASEBALL SIZE...DAMAGING WIND
GUSTS...AND TORNADOES.

ADDITIONAL SEVERE THUNDERSTORMS ARE EXPECTED LATER THIS EVENING
INTO THE OVERNIGHT PERIOD AS THE COVERAGE OF THUNDERSTORMS GRADUALLY
INCREASES AND EVOLVES INTO A LINE OF STORMS DURING THE OVERNIGHT
HOURS. LARGE HAIL...STRONG STRAIGHT LINE WINDS AND TORNADOES WILL
REMAIN POSSIBLE DURING THE NIGHT TIME HOURS OVER MUCH OF THE AREA.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

THUNDERSTORMS ARE EXPECTED TO BE ONGOING IN FAR EASTERN KANSAS
AROUND SUNRISE SUNDAY...AND WILL EXIT THE AREA PRIOR TO MIDDAY.

THE NEXT CHANCE OF THUNDERSTORMS IS THURSDAY THROUGH FRIDAY AS AN
UPPER DISTURBANCE MOVES THROUGH THE AREA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED THIS AFTERNOON INTO THE
LATE EVENING HOURS.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TOPEKA KS
227 PM CDT SAT APR 14 2012

KSZ008-009-020-021-142000-
CLAY-CLOUD-REPUBLIC-WASHINGTON-
227 PM CDT SAT APR 14 2012

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN REPUBLIC...NORTHERN
CLAY...CLOUD AND WASHINGTON COUNTIES...

THROUGH 300 PM CDT...A COUPLE OF STRONG THUNDERSTORMS WILL MOVE
NORTH AT 60 MPH ACROSS PORTIONS OF EASTERN REPUBLIC...NORTHERN
CLAY...NORTHERN CLOUD AND WASHINGTON COUNTIES. NATIONAL WEATHER
SERVICE DOPPLER RADAR INDICATED THESE STORMS ARE CAPABLE OF
PRODUCING NICKEL SIZE HAIL. SOME LOCATIONS THAT COULD BE AFFECTED
INCLUDE
CLYDE...VINING...CLIFTON...AGENDA...PALMER...BELLEVILLE...LINN...
CUBA...GREENLEAF...MUNDEN...HADDAM...MORROWVILLE AND WASHINGTON.

A TORNADO WATCH IS ALSO IN EFFECT.

&&

LAT...LON 3928 9713 3947 9782 3999 9762 3982 9689
TIME...MOT...LOC 1927Z 202DEG 56KT 3942 9718 3955 9766