Tornado and Flash Flooding in Kansas, May 26, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
400 PM CDT SAT MAY 26 2007

.DISCUSSION...
MAIN CONCERNS ARE CHANCES FOR PRECIPITATION NEXT FEW DAYS.

WEAK SFC BNDRY MOVING INTO THE AREA TONIGHT WITH DECENT PRECIPITABLE
WATER VALUES...AROUND 150-175% OF NORMAL...BEG FOR AT LEAST HIGH
CHANCE POPS. AS MENTIONED BY EARLIER SPC NARRATIVES, CHANCES FOR
SEVERE CONVECTION ARE RATHER SMALL...BUT NOT ZERO. SHEAR NOT TOO
STRONG AND CONVERGENCE ALONG FRONT WEAK. UPPER SUPPORT NIL.
AFTERNOON HEATING MAIN DRIVING FORCE FOR ANY SGFNT CONVECTION
INCLUDING POCKETS OF INTENSE RAIN. THIS SHOULD BECOME LESS
WIDESPREAD OVERNIGHT...BUT NOT LIKELY DMSH ALTOGETHER AS PESKY FRONT
MEANDERS OVER THE AREA. THIS SFC BNDRY WILL LIKELY DISSIPATE FURTHER
ON SUNDAY WITH H850 FLOW RETURNING TO SOUTHERLY BY TMRW EVENING.
THIS SHOULD EFFECTIVELY LOWER POPS TO SLIGHT CHC CATEGORY UNTIL
FRONTAL BNDRY ENTERS AREA IN THE TUESDAY-TUESDAY NIGHT TIME PD. THIS
FRONTAL TIMING OF MAJOR CONCERN TOO AS EARLIER FORECASTS HAD
PRECIPITATION LINGERING INTO WEDNESDAY NIGHT. GFS A BIT FASTER WITH
FRONTAL MOVEMENT WHILE NAM HAS IT INTO THE AREA BY TUESDAY
AFTERNOON. THIS LATTER MOVEMENT SEEMS A BIT TOO FAST...GIVEN SLOW
PROGRESSION OF EURO AND UK MODELS. WILL MAINTAIN POPS INTO WEDNESDAY
AND CONTINUE TO WATCH TREND OF MODELS.

TEMPERATURES SHOULD BE FAIRLY PERSISTENT UNTIL CLOUDS DECREASE/WINDS
INCREASE. THAT COULD COME BY MONDAY WITH MOSTLY 80S EXPECTED BY
THEN. DIDNT ADD ANY GUSTY GRIDS BUT GRADIENT DEFINITELY ON THE
INCREASE BY MONDAY. LATER SHIFTS MAY WANT TO CONSIDER THEM.

BIG MESSAGE IN THE LATER PERIODS IS A MAJOR CHANGE IN THE UPPER AIR
PATTERN. GFS ADVERTISING RETURN TO A SUMMER TIME NORTHWEST FLOW
REGIME BY WEEKS END. EURO AND UK ALSO CHANGING PATTERN BUT TO A
SOMEWHAT COOLISH NORTHERLY FLOW REGIME. IN ANY CASE, APPEARS THERE
IS A CHANGE FROM A RELATIVELY WET PATTERN TO A DRYER PATTERN. GOOD
NEWS FOR FLOOD WEARY FOLKS.

&&

.AVIATION...

MOST CEILINGS HAVE LIFTED TO VFR BY EARLY AFTERNOON OUTSIDE OF AREAS
OF CONVECTION...WHERE CEILINGS DOWN TO 1500-2500 FEET AT TIMES. WILL
CONTINUE THIS TREND INTO EARLY EVENING HOURS WILL MAIN AREA OF
SHOWERS AND THUNDERSTORMS THEN AROUND 4000 FT BY SUNSET. COLD FRONT
NEAR THE NEBRASKA BORDER WILL CONTINUE TO SINK SOUTH AND BE THE
FOCUS FOR MORE CONVECTION THIS AFTERNOON/EARLY EVENING...BUT NO
CONFIDENT ENOUGH THAT THE CONVECTION WILL MOVE INTO TAF SITES TO
CARRY ANYTHING MORE THAN SHOWERS VICINITY THROUGH THE EVENING. COLD
FRONT WILL BRING A GRADUAL WINDSHIFT INTO ALL TAF SITES BY LATE
EVENING. AREA OF MVFR CEILINGS NOW BEHIND THE FRONT EXPECTED TO
SPREAD INTO THE AREA OVERNIGHT AS WINDS BECOME LIGHT NORTHEAST. SOME
LIGHT FOG ALSO POSSIBLE WITH RESIDUAL MOISTURE AND LIGHT WINDS
09-13Z..OTHERWISE KEPT CEILINGS GENERALLY 2500-3000 FEET OVERNIGHT
THROUGH 18Z SUNDAY.

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
1157 AM CDT SAT MAY 26 2007

KSZ008>012-020>024-026-034>040-054>056-058-059-271700-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
1157 AM CDT SAT MAY 26 2007

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

.DAY ONE...TODAY AND TONIGHT

RIVER FLOODING WILL CONTINUE TODAY ON PORTIONS OF THE SMOKY HILL
RIVER AND THE BIG BLUE RIVER.

SCATTERED TO THUNDERSTORMS ARE EXPECTED ACROSS THE ENTIRE AREA
THIS AFTERNOON INTO EARLY TONIGHT. A FEW OF THE STORMS MAY BE
CAPABLE OF SMALL HAIL AND GUSTY WINDS. LOCALLY HEAVY RAINFALL
IS ALSO EXPECTED WHICH COULD PRODUCE ISOLATED FLASH FLOODING AND
AGGRAVATE ONGOING RIVER FLOODING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THUNDERSTORMS ARE LIKELY TO REDEVELOP ACROSS NORTHEAST...NORTH
CENTRAL AND EAST CENTRAL KANSAS SUNDAY AND CONTINUE INTO SUNDAY
EVENING AS A FRONT MEANDERS ACROSS THE REGION. AN ISOLATED STORM
MAY BE CAPABLE OF PRODUCING SEVERE WEATHER.

THERE IS A CHANCE FOR THUNDERSTORMS MONDAY THROUGH WEDNESDAY ACROSS
THE ENTIRE AREA.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT RAINFALL AMOUNTS OVER ONE INCH
TO THE NATIONAL WEATHER SERVICE IN TOPEKA.

SIGNIFICANT WEATHER ALERT
NATIONAL WEATHER SERVICE TOPEKA KS
349 PM CDT SAT MAY 26 2007

KSZ022-023-038-262115-
POTTAWATOMIE-RILEY-WABAUNSEE-
349 PM CDT SAT MAY 26 2007

THROUGH 415 PM CDT...A SMALL CLUSTER OF STRONG THUNDERSTORMS WILL
MOVE NORTHEAST AT 15 MPH ACROSS SOUTHEASTERN RILEY...SOUTHERN
POTTAWATOMIE...AND FAR NORTHWESTERN WABAUNSEE 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. THUNDERSTORMS HAVE BEEN MOVING OVER THE
SAME LOCATIONS OVER THE PAST 45 MINUTES...WITH RAINFALL OF 1 TO 2
INCHES LIKELY ALREADY FALLING IN SOME LOCATIONS. ADDITIONAL HEAVY
RAINS MAY RESULT IN LOCALIZED FLOODING. SOME COMMUNITIES THAT COULD
BE AFFECTED INCLUDE BELVUE...WAMEGO...SAINT GEORGE...AND LOUISVILLE.

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