Hail and Damaging Winds in Kansas, June 1 to 2, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
647 AM CDT TUE JUN 1 2010

.UPDATE...

UPDATE FOR 12Z AVIATION.

&&

.DISCUSSION...

SEE PREVIOUS DISCUSSION.

&&

.AVIATION...

WARM/MOIST AIR ADVECTION GIVING RISE TO ELEVATED CONVECTION IN
WESTERN KANSAS...AND MORE RECENTLY IN EASTERN KANSAS. LOW/MID
LEVEL WIND FIELDS SUGGEST ANY NEARBY ACTIVITY WILL INITIALLY MOVE
SOUTHEAST AND SHOULD REMAIN SOUTH OF THE TERMINALS...WITH UPPER
WINDS VEERING FOR A MORE NORTHEAST TRAJECTORY LATER THIS MORNING
AND AFTERNOON. WILL INCLUDE CB GROUP FROM MID MORNING THROUGH
EARLY AFTERNOON AT THIS TIME. REMAINDER OF THE FORECAST WILL BE
DRY WITH CONFIDENCE ON ANY ADDITIONAL CONVECTION QUITE LOW
THROUGH WEDNESDAY MORNING.

65

&&

.PREV DISCUSSION... /ISSUED 318 AM CDT TUE JUN 1 2010/

DISCUSSION...

CONCERNS RESIDE WITH PRECIP CHANCES AND LOCATIONS FOR DEVELOPMENT
IN FIRST 48 HOURS OF THE FORECAST.

FOR TODAY...FORECAST CONFIDENCE FOR PLACEMENT OF TODAYS CONVECTION
IS LOW TO MODERATE. WEAK ECHOES DEVELOPING ACROSS SOUTHERN CWA
ATTM...AS LLJ INCREASES FROM THE SW AND MID LEVEL FRONT CURRENTLY
LIES NW TO SE ACROSS THE CWA. SHORTWAVE IN THE FLOW ALSO LIKELY
AIDING IN LIFT ALONG THE BDRY. CONVECTIVE OUTFLOW LIFTING
NORTHWARD OUT OF OK LIKELY TO AID IN REINFORCING CONVECTION OUT
IN WESTERN KS. QUESTION WOULD BE HOW MUCH EASTWARD PROGRESS THOSE
STORMS CAN MAKE BEFORE WARM 700MB TEMPS ADVECT IN FROM THE SW AND
CAP OFF CONVECTION. GFS BLOWS UP CONVECTION RIGHT OVER OUR AREA
MID DAY...WHICH ALSO HAS RESIDUAL EFFECTS ON THE REMAINDER OF THE
FORECAST FOR THIS PERIOD. NOSE OF LLJ WOULD FAVOR TRACK OF STORMS
OUT WEST INTO SOUTHERN NEBRASKA MORESO THAN EASTERN TOWARD OUR
CWA. WILL CARRY SOME SLT CHANCE POPS WITH SLIGHTLY HIGHER NUMBERS
IN NC COUNTIES FOR THIS MORNING AS A RESULT OF THIS THINKING.
WILL CONTINUE POPS ALONG NORTHERN COUNTIES INTO THE AFTERNOON BUT
DIMINISH POPS IN SW COUNTIES AS LIFT AND CAP BECOME LESS
FAVORABLE FOR DEVELOPMENT THERE THROUGH THE AFTERNOON HOURS.
MIXING SHOULD BRING VERY WARM TEMPERATURES INTO THE UPPER 80S EAST
AND LOWER 90S IN WESTERN COUNTIES.

TONIGHT...SFC BOUNDARY GETS A PUSH SOUTHWARD AS UPPER LOW TRACKS
ALONG THE CANADIAN BORDER THIS AFTERNOON INTO TONIGHT. ADDITIONAL
WAVE LIFTING OVER THE ROCKIES BRINGS SFC LOW INTO THE HIGH PLAINS
OF WRN KS THIS EVENING. CONVERGENCE FAVORS CONVECTIVE DEVELOPMENT
IN NEBRASKA WHERE LLJ INTERSECTS THE FRONT AND SOME SOUTHWARD
DEVELOPMENT INTO NC KS INVOF INVERTED SFC TROF. WSW FLOW ALOFT
WOULD ALSO FAVOR STORMS TO PROPAGATE EASTWARD AND SHOULD KEEP
CONVECTION MAINLY NORTH OF INTERSTATE 70 IN THE OVERNIGHT HOURS.
VERY STRONG INSTABILITY ACROSS EASTERN KS POOLS ALONG THE BOUNDARY
THROUGH THE DAY...AND WITH SHEAR INCREASING TO 30-40KTS...THERE
IS THE THREAT FOR STRONG TO SEVERE STORMS ACROSS THE NORTH. PW
VALUES OF 1-2 INCHES WILL MAKE HEAVY RAINFALL FROM ANY TRAINING
STORMS A CONCERN AS WELL. IT IS WORTH NOTING THAT MODEL GUIDANCE
FOR INSTABILITY ALONG AND AHEAD OF THIS FRONT RANGES FROM
2000-4000J/KG...AND WHILE LIKELY SOMEWHAT OVERDONE...THESE
NUMBERS WOULD MAKE LARGE HAIL A CONSIDERABLE THREAT IF INSTABILITY
IS REALIZED.

WEDNESDAY...FORECAST FOR WEDNESDAY WILL BE AFFECTED CONSIDERABLY BY
OUTFLOW AND CLOUD COVER FROM OVERNIGHT CONVECTION...WITH STORM
STRENGTH DRIVEN IN MORE MESOSCALE TIMEFRAME. OVERALL PATTERN
DEPICTS FRONT MAKING A STRONG PUSH SOUTHWARD THROUGH THE CWA
THROUGH THE DAY ON WEDNESDAY. STRONG INSTABILITY STILL
ADVERTISED AHEAD OF THIS FRONT...WITH VALUES INCREASING TOWARD
THE EAST CENTRAL COUNTIES. OVERALL PATTERN SUGGESTS FRONT PASSING
ACROSS EASTERN KS DURING PEAK HEATING WITH STRONG INSTABILITY AND
WIND SHEAR AVAILABLE FOR SEVERE POTENTIAL TO CONTINUE THROUGH
WEDNESDAY...DECREASING NW TO SE AS THE DAY AND FRONT PROGRESSES.
MUCH WILL DEPEND ON WEATHER OVER NEXT 24 HOURS.

THURS/FRI...FRONT PUSHES SOUTHWARD OF OUR AREA AND TAPERED POPS
OVERNIGHT AND TOOK OUT PRECIP CHANCES ON THURSDAY DAY. COOLER
HIGHS IN THE LOWER 80S ANTICIPATED. ANOTHER POTENTIAL MCS ACROSS
NEBRASKA THURSDAY NIGHT INTO FRIDAY COULD COOL OFF THE NORTHERN
COUNTIES FOR FRIDAY...OTHERWISE MID TO UPPER 80S EXPECTED. NO
CHANGES BEYOND FRIDAY. 67

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
500 AM CDT TUE JUN 1 2010

KSZ008>012-020>024-026-034>040-054>056-058-059-021000-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
500 AM CDT TUE JUN 1 2010

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

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS THE AREA
TODAY...WITH THUNDERSTORM CHANCES ACROSS THE NORTH AND EAST
CENTRAL COUNTIES CONTINUING INTO THE AFTERNOON AND EVENING HOURS.

STRONG STORMS ARE EXPECTED TO DEVELOP ALONG A FRONT ACROSS
SOUTHERN NEBRASKA LATER TODAY. THESE STORMS MAY MOVE INTO
NORTHERN KANSAS AND BRING THE POTENTIAL FOR LARGE HAIL AND
DAMAGING WINDS IN THE EVENING AND OVERNIGHT HOURS TO AREAS NORTH
OF INTERSTATE 70. STORMS THAT DEVELOP ARE ALSO LIKELY TO CONTAIN
HEAVY RAINFALL...AND LOCALIZED FLOODING WILL ALSO BE A CONCERN FOR
THIS AREA.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE POTENTIAL FOR STRONG TO SEVERE STORMS CONTINUES INTO WEDNESDAY
AS THE FRONT PUSHES SOUTHWARD ACROSS THE AREA.

NIGHTTIME THUNDERSTORM CHANCES CONTINUE THROUGH THE WEEK AS A
FRONTAL BOUNDARY STALLS ACROSS THE PLAINS.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS GENERALLY NORTH OF INTERSTATE 70 MAY BE NEEDED THIS
EVENING AND OVERNIGHT...PRIMARILY FOR HAIL AND RAINFALL REPORTS.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TOPEKA KS
723 AM CDT TUE JUN 1 2010

KSZ054>056-058-059-011300-
ANDERSON-COFFEY-FRANKLIN-LYON-OSAGE-
723 AM CDT TUE JUN 1 2010

...SIGNIFICANT WEATHER ALERT FOR OSAGE...LYON...FRANKLIN...COFFEY AND
ANDERSON COUNTIES...

THROUGH 800 AM CDT...A LINE OF THUNDERSTORMS WILL MOVE NORTHEAST AT
20 MPH ACROSS PORTIONS OF OSAGE...LYON...FRANKLIN...COFFEY AND
ANDERSON COUNTIES. NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THESE A FEW OF THE STORMS IN THIS LINE ARE CAPABLE OF PRODUCING DIME
SIZE HAIL. SOME LOCATIONS THAT COULD BE AFFECTED INCLUDE
GARNETT...WILLIAMSBURG...QUENEMO...RICHMOND...POMONA...PRINCETON AND
GREELEY. MOTORISTS ALONG INTERSTATE 35 BETWEEN MILE MARKERS 141 AND
184 COULD ALSO BE AFFECTED.

STAY ALERT TO THE WEATHER IN CASE A WARNING IS ISSUED.