Hail and Damaging Winds in Kansas, June 27, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1255 PM CDT THU JUN 27 2013

...UPDATED SHORT TERM AND AVIATION DISCUSSION...

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 1232 PM CDT THU JUN 27 2013

AT 18Z...AN OUTFLOW BOUNDARY EXTENDED FROM NEAR OTTAWA TO JUNCTION
CITY TO WASHINGTON...AND HAD ALREADY MIXED OUT A BIT NEAR THE
NEBRASKA BORDER AS EVIDENCED BY BEATRICE WINDS TURNING OUT OF THE
SSE. THE COLD SIDE OF THE OUTFLOW HAD STABALIZED A BIT AT THE
SURFACE BUT ELEVATED PARCELS REMAINED VERY UNSTABLE. MEANWHILE...
THE WARM SIDE OF THE OUFLOW WAS EXTREMELY UNSTABLE WITH DEWPOINTS
IN THE MID 70S AND TEMPERATURES CLIMBING WELL INTO THE 90S. DEEP
LAYER SHEAR IS SUFFICIENT FOR SUPERCELL STRUCTURES PARTICULARLY
WHEN COMBINED WITH THE EXTREME INSTABILITY IN PLACE. A SOMEWHAT
ORGANIZED AREA OF CONVECTION HAS BEEN STEADILY MOVING SSE ACROSS
SOUTHEAST NEBRASKA AND HAS SHOWN SIGNS OF INCREASING ORGANIZATION
AND DEVELOPMENT ON THE WESTERN FLANK WHERE THE INSTABILITY FEED IS
MORE SUBSTANTIAL.

FEEL THAT THE MOST LIKELY SCENARIO FOR THIS AFTERNOON AND EVENING
IS FOR THE ACTIVITY IN SOUTHERN NEBRASKA TO FURTHER ORGANIZE...
LIKELY DEVELOPING A FORWARD PROPAGATING COLD POOL WHILE ALSO
MAINTAINING EMBEDDED SUPERCELL STRUCTURES. THIS SEEMS TO BE A
RATHER FAVORABLE SETUP FOR A DAMAGING WIND EVENT...ESPECIALLY
ANYWHERE ON THE WARM SIDE OF THE OUTFLOW BOUNDARY BUT PERHAPS
EXTENDING INTO THE COOL SIDE OF THE OUTFLOW BY 100 MILES OR SO AS
WELL. THE MAGNITUDE OF INSTABILITY ALONG WITH THE SHEAR PROFILE
SUGGEST THE POTENTIAL FOR VERY LARGE HAIL...PERHAPS ACCOMPANIED BY
VERY STRONG WINDS AT TIMES. TORNADO POTENTIAL IS NON-ZERO...BUT
WOULD SEEM TO BE LIMITED TO AREAS WHERE THE STORMS INTERSECT THE
REMNANT OUTFLOW BOUNDARY AND TO ANY ORGANIZED CELLS ON THE WEST
END OF ANY BOW ECHO. WOULD ALSO NEED TO KEEP AN EYE ON ANY BOOKEND
VORTEX THAT COULD DEVELOP IN A WELL ORGANIZED BOW ECHO. THE BOTTOM
LINE IS THAT AN ORGANIZED SEVERE WEATHER THREAT IS EXPECTED THIS
AFTERNOON WITH THE PRIMARY THREATS BEING A COMBINATION OF WINDS UP
TO 80 MPH AND HAIL UP TO TENNIS BALL SIZE. DO EXPECT STORMS TO
COME TO AN END BY LATE EVENING WITH MORE PLEASANT CONDITIONS
EVENTUALLY SETTLING INTO THE AREA BEHIND AN INCOMING COLD FRONT.

BARJENBRUCH

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 313 AM CDT THU JUN 27 2013

QUITE A PATTERN CHANGE ON THE WAY FRIDAY INTO THE WEEKEND. COOL
CANADIAN HIGH PRESSURE SURGES SOUTHWARD UNDER NORTHERLY FLOW
ALOFT...DROPPING TEMPERATURES TO AROUND 90 FRIDAY WITH A FALL IN
TO THE 80S TO LOWER 80S BY THE END OF THE WEEKEND. HIGHLY
AMPLIFIED MERIDIONAL UPPER PATTERN CONTINUES THROUGH
TUESDAY...WITH ANOTHER PIECE OF ENERGY ROTATING THROUGH THE FLOW
INTO THE BACKSIDE OF THE UPPER EASTERN TROF...POSSIBLY RETROGRADING
IT BACK WESTWARD OVER THE CENTRAL PLAINS BY MID WEEK. THIS WOULD
BRING INCREASED CHANCE FOR PRECIP TOWARD WEDNESDAY AND WILL
REFLECT IN FORECAST. ALSO STILL A SIGNAL FOR AN IMPULSE TO MOVE
ACROSS THE EAST ON SUNDAY AND WILL CARRY SLIGHT CHANCE THEN AS
WELL. OTHERWISE A DRY AND BELOW NORMAL FORECAST FOR THE WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1232 PM CDT THU JUN 27 2013

A LINE OF STRONG TO SEVERE TSRA WILL IMPACT MHK...AND LIKELY
TOP/FOE THIS AFTERNOON WITH VERY LARGE HAIL AND DAMAGING WINDS
POSSIBLE. MHK SEEMS TO BE DIRECTLY IN LINE WITH THIS POTENTIAL
WHILE TOP/FOE MAY BE ON THE EASTERN FRINGE OF THE STRONGEST WINDS.
HAVE TRIED TO IDENTIFY A 2 HOUR WINDOW FOR WORST CONDITIONS IN
TEMPO GROUP WITH FAIR CONFIDENCE IN TIMING. MAGNITUDE OF WIND
SPEEDS MAY NEED TO BE INCREASED AS CONFIDENCE IN SPEEDS INCREASES.
OTHER THAN TSRA POTENTIAL...VFR CONDITIONS ARE EXPECTED FOR THE
MAJORITY OF THE TAF.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ020>022-034>038-
054>056-058-059.

&&

SHORT TERM...BARJENBRUCH
LONG TERM...67
AVIATION...BARJENBRUCH

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
1230 PM CDT THU JUN 27 2013

KSZ008>012-020>024-026-034>040-054>056-058-059-281730-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
1230 PM CDT THU JUN 27 2013

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

A ROUND OF STRONG TO SEVERE THUNDERSTORMS IS EXPECTED THIS
AFTERNOON AND EVENING ACROSS THE ENTIRE AREA ALONG AN ADVANCING
COLD FRONT. HAIL TO TENNIS BALL SIZE OR LARGER AND DAMAGING WINDS
UP TO 80 MPH ARE EXPECTED WITH THE STRONGEST STORMS LATE TODAY.
THERE IS ALSO A SMALL POTENTIAL FOR ONE OR TWO TORNADOES. THE
GREATEST POTENTIAL FOR SEVERE STORMS IS NEAR AND SOUTHWEST OF A
LINE FROM MARYSVILLE TO TOPEKA TO OTTAWA.

A HEAT INDEX OF 104 TO 109 DEGREES IS EXPECTED ACROSS PARTS OF
NORTH CENTRAL AND EAST CENTRAL KANSAS TODAY.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

THUNDERSTORMS ARE POSSIBLE SUNDAY IN PORTIONS OF NORTHEAST AND
EAST CENTRAL KANSAS...AND FOR THE ENTIRE AREA TUESDAY NIGHT AND
WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED THIS AFTERNOON AND
EVENING...PARTICULARLY NEAR AND WEST OF A LINE FROM MARYSVILLE TO
TOPEKA TO OTTAWA.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TOPEKA KS
1013 AM CDT THU JUN 27 2013

KSZ011-012-271545-
BROWN-NEMAHA-
1013 AM CDT THU JUN 27 2013

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN NEMAHA AND
NORTHWESTERN BROWN COUNTIES...

THROUGH 1045 AM CDT...A STRONG THUNDERSTORM WILL MOVE SOUTHEAST AT 25
MPH ACROSS PORTIONS OF NORTHEASTERN NEMAHA AND NORTHWESTERN BROWN
COUNTIES. NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THIS STORM
IS CAPABLE OF PRODUCING NICKEL SIZE HAIL AND STRONG WINDS OF 40 TO 50
MPH. SOME LOCATIONS THAT COULD BE AFFECTED INCLUDE SABETHA...
MORRILL...FAIRVIEW...HAMLIN AND RESERVE.

A SEVERE THUNDERSTORM WATCH IS ALSO IN EFFECT.

&&

LAT...LON 3980 9559 3985 9584 4000 9598 4001 9592
      4000 9540
TIME...MOT...LOC 1514Z 294DEG 20KT 4003 9583

BARJENBRUCH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TOPEKA KS
1107 AM CDT THU JUN 27 2013

KSZ012-271645-
BROWN-
1107 AM CDT THU JUN 27 2013

...SIGNIFICANT WEATHER ADVISORY FOR BROWN COUNTY...

THROUGH 1145 AM CDT...A STRONG THUNDERSTORM WILL MOVE SOUTHEAST AT 35
MPH ACROSS PORTIONS OF BROWN COUNTY. NATIONAL WEATHER SERVICE DOPPLER
RADAR INDICATED THIS STORM IS CAPABLE OF PRODUCING NICKEL SIZE HAIL
AND STRONG WINDS OF 40 TO 50 MPH. SOME LOCATIONS THAT COULD BE
AFFECTED INCLUDE POWHATTAN...HIAWATHA...WILLIS...ROBINSON AND
EVEREST.

A SEVERE THUNDERSTORM WATCH IS ALSO IN EFFECT.

&&

LAT...LON 3985 9533 3965 9534 3965 9539 3982 9578
      3994 9576
TIME...MOT...LOC 1607Z 295DEG 29KT 3986 9565

BARJENBRUCH