Special Weather Statement, NWS Topeka, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
301 PM CDT WED JUL 27 2011

.DISCUSSION...

SHORT TERM (THROUGH THURSDAY)...

THIS AFTERNOON AND TONIGHT....A SURFACE COLD FRONT EXTENDED FROM
SOUTHEAST NE...SOUTHWEST ACROSS WEST CENTRAL KS INTO SOUTHEAST CO.
WEAK SFC CONVERGENCE ALONG WITH CONVECTIVE TEMPS BEING REACHED
SHOULD CAUSE ISOLATED TO SCATTERED THUNDERSTORMS TO DEVELOP EAST OF
THE FRONT...AND ALSO ALONG A WEAK DRY LINE WHICH EXTENDING FROM
WESTERN OK...NORTHEAST TO THE COLD FRONT NORTH OF SLN. A WEAK UPPER
LEVEL DISTURBANCE WAS NOTED ON WATER VAPOR SATELLITE LIFTING
NORTHEAST ACROSS NORTHEAST CO INTO NE. WEAK ASCENT AHEAD OF THIS
WEAK UPPER LEVEL TROUGH WILL MOVE ACROSS NE AND NORTHERN KS THIS
EVENING. THE ASCENT MAY HELP TO EXPAND THE COVERAGE OF THUNDERSTORMS
ALONG THE FRONT. SOME OF THE THUNDERSTORMS MAY PRODUCE VERY HEAVY
RAINFALL AND GUSTY WINDS...MAY EVEN SEE SOME ISOLATED SEVERE WIND
GUSTS ACROSS NORTH CENTRAL KS LATE THIS AFTERNOON INTO THE EARLY
EVENING HOURS. IF A COLD POOL DEVELOPS WITH INITIAL STORMS...WE MAY
SEE AN OUTFLOW BOUNDARY MOVE SOUTHEAST ACROSS THE REMAINDER OF THE
CWA WHICH MAY PROVIDE ENOUGH SURFACE CONVERGENCE FOR ISOLATED TO
SCATTERED THUNDERSTORMS ACROSS EAST CENTRAL KS THROUGH THE EVENING
HOURS. THE WEAK UPPER LEVEL TROUGH WILL MOVE EAST OF THE AREA AFTER
MIDNIGHT. THE THUNDERSTORMS SHOULD WEAKEN AND DECREASE IN COVERAGE
AFTER MIDNIGHT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS THROUGH THE
NIGHT NORTH OF THE SURFACE FRONT ACROSS NORTHEAST AND NORTH CENTRAL
KS. OVERNIGHT LOWS WILL BE IN THE LOWER TO MID 70S ACROSS THE
NORTHERN HALF THE CWA WITH UPPER 70S AND LOWER 80S ACROSS THE
SOUTHERN COUNTIES. THE FRONT SHOULD BECOME STATIONARY TONIGHT ACROSS
THE NORTHERN HALF OF THE CWA.

THURSDAY...A MORE INTENSE H5 TROUGH WILL MOVE EAST FROM THE
PACIFIC NORTHWEST INTO THE NORTHERN AND CENTRAL PLAINS BY THURSDAY
AFTERNOON AND EVENING. THE STATIONARY FRONT ACROSS THE NORTHERN
COUNTIES OF THE CWA WILL BEGIN TO MOVE SOUTHEAST DURING THE
AFTERNOON HOURS. STRONGER ASCENT AHEAD OF THE APPROACHING H5
TROUGH WILL CAUSE SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP
AHEAD AND NORTH OF THE COLD FRONT. THE INCREASED MID-LEVEL FLOW
WILL CAUSE THE VERTICAL WIND SHEAR TO BE STRONGER...AND MAY
INCREASE OUR CHANCES FOR MORE ORGANIZED SEVERE THUNDERSTORMS.
THOUGH THE PRIMARY HAZARDS WILL BE DAMAGING WIND GUSTS AND QUARTER
SIZE HAIL. HIGH TEMPERATURES TO THE NORTH OF THE FRONT WILL ONLY
REACH INTO THE LOWER TO MID 90S...HIGHS ALONG AND SOUTH OF THE
FRONT WILL REACH TO AROUND 100 DEGREES WITH SOME AREAS OF MORRIS
AND LYON COUNTY REACHING 106 DEGREES ONCE AGAIN. HEAT INDICES WILL
BE IN THE 105 TO 110 DEGREE RANGE ALONG AND SOUTH OF I-70...WITH
99 TO 104 NORTH OF THE BOUNDARY DUE TO HIGHER DEWPOINTS WHICH MAY
POOL NORTH OF THE BOUNDARY. THE CURRENT EXCESSIVE HEAT WARNING FOR
THURSDAY LOOKS GOOD AND I WILL NOT MAKE ANY CHANGES. IF THE FRONT
IS A BIT FASTER...THEN SOME AREAS ALONG THE I-70 CORRIDOR MAY BE A
BIT COOLER.

GARGAN

LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)...

THE MAIN FOCUS OF THIS FORECAST PERIOD WILL BE THUNDERSTORM
POTENTIAL THURSDAY NIGHT THROUGH SATURDAY AND THE RETURN OF HOT
TEMPERATURES EARLY NEXT WEEK.

A FRONTAL BOUNDARY WILL PUSH WELL INTO THE AREA BY LATE THURSDAY
WITH A MODERATE TO STRONGLY UNSTABLE ENVIRONMENT NEAR AND NORTH OF
THIS FRONT. EXPECT TO SEE A FEW STORMS IN THIS ZONE DURING THE
EVENING HOURS WITH POTENTIAL FOR DAMAGING WINDS NEAR THE FRONT IN
PARTICULAR...AND HEAVY RAIN AS WELL GIVEN PWAT VALUES IN EXCESS OF
2 INCHES. AS THE EVENING ADVANCES...A STOUT LOW LEVEL JET IS
FORECAST TO DEVELOP AND INTERSECT THE FRONTAL BOUNDARY WITH A
ZONE OF DEEP CONVERGENCE NEAR AND JUST NORTH OF THE FRONT ACROSS
MUCH OF KANSAS. THERE IS A FAIRLY STRONG SIGNAL REGARDING
DEVELOPMENT OF AN MCS THAT WOULD AFFECT MUCH OF THE FORECAST AREA.
WILL BE SOME POTENTIAL FOR THIS SYSTEM TO FORWARD PROPAGATE ALONG
THE EASTERN FLANK NEAR AND JUST NORTH OF THE FRONT IF IT CAN
MAINTAIN A GOOD MOISTURE FEED...WHICH WOULD PRESENT SOME THREAT OF
DAMAGING WINDS. HOWEVER...AS THE LOW LEVEL JET BEGINS TO VEER...
WILL ALSO SEE POTENTIAL FOR THE MCS TO BACKBUILD ALONG THE FRONT
WITH INDIVIDUAL CELLS TRAINING NEAR AND JUST NORTH OF THE FRONT
IN THE ATMOSPHERE CHARACTERIZED BY 2 TO 2.4 INCH PWAT VALUES. AS A
SIDE NOTE...THIS TRAINING SCENARIO WOULD BE MORE LIKELY IF A
FORWARD PROPAGATING MCS FAILS TO DEVELOP. THAT SAID...HEAVY RAIN
WILL BE POSSIBLE THROUGH EARLY FRIDAY ACROSS THE ENTIRE AREA.
MORNING STORMS WILL MOVE EAST AND WEAKEN WITH SOME POTENTIAL FOR
SCATTERED AFTERNOON REDEVELOPMENT. SLIGHT TSTORM CHANCES REMAIN
THROUGH SATURDAY WITH THE SURFACE FRONT REMAINING JUST SOUTH OF
THE AREA AND WEAK SOUTHERLY FLOW OVERRIDING THE BOUNDARY.

WITH PRECIP AND CLOUDS...AS WELL AS THE POST FRONTAL ENVIRONMENT
IN PLACE...TEMPERATURES ARE EXPECTED TO COOL A BIT FOR FRIDAY
BEFORE WARMING BACK INTO THE MID 90S BY THE WEEKEND. DEWPOINTS
NORTH OF THE FRONT WILL LIKELY REMAIN IN THE 70S FOR MUCH OF THE
AREA SO ANTICIPATE ELEVATED HEAT INDICES ONCE AGAIN DESPITE THE
SLIGHTLY COOLER TEMPERATURES.

WHILE GFS GUIDANCE KEEPS OCCASIONAL RAIN CHANCES IN THE AREA NEXT
WEEK...THIS WOULD APPEAR UNLIKELY AS THE UPPER LEVEL RIDGE IS
FORECAST TO BUILD OVER THE CENTRAL PLAINS ONCE AGAIN WITH BROAD
SUBSIDENCE ALOFT AND NO GREAT FOCUS IN THE LOW LEVELS. THUS HAVE A
DRY FORECAST UNTIL WEDNESDAY. HAVE ALSO FORECAST WARMER THAN MOST
GUIDANCE FOR MONDAY AND TUESDAY. ALTHOUGH 850 TEMPS ARE NOT
FORECAST TO BE QUITE AS HIGH AS THE RECENT HEAT WAVE...SHOULD NOT
BE AN ISSUE TO REACH THE 100 DEGREE MARK YET AGAIN. ANOTHER COLD
FRONT IS FORECAST TO SINK ACROSS NEBRASKA AND PERHAPS INTO KANSAS
BY WEDNESDAY...WITH THUNDERSTORM CHANCES NEAR THE FRONT ONCE
AGAIN. CONFIDENCE IN THIS FEATURE IS LOW AT THIS TIME AND HAVE NOT
GONE ABOVE SLIGHT CHANCES FOR PRECIP.

BARJENBRUCH

&&

.AVIATION...

VFR CONDITIONS EXPECTED AT TERMINALS THROUGH FORECAST PERIOD.
SOUTHERLY WINDS MAY GUST UP TO 30 KTS AT TIMES WEDNESDAY AFTERNOON
AS DEEP MIXING TO THE SURFACE CONTINUES. A FRONTAL BOUNDARY THIS
EVENING WILL BE THE MAIN FOCUS FOR THUNDERSTORM DEVELOPMENT AS IT
APPROACHES FROM NEBRASKA. MODEL TRENDS BRING THE FRONT SLOWLY
SOUTHWARD...CLOSEST TO KMHK WHERE A CB WAS MENTIONED. UNCERTAINTY
INCREASES FOR KTOP AND KFOE WHERE THE BOUNDARY MAY NOT REACH THAT
FAR SOUTH. FOR NOW...WILL MONITOR AND UPDATE AS NECESSARY.

BOWEN

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR
KSZ008>012-020>024-034>036.

EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THURSDAY FOR KSZ026-
037>040-054>056-058-059.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
337 PM CDT WED JUL 27 2011

KSZ008>012-020>024-026-034>040-054>056-058-059-282045-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
337 PM CDT WED JUL 27 2011

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

AN EXCESSIVE HEAT WARNING WILL REMAIN IN EFFECT FOR THE AREA
THROUGH 700 PM. HEAT INDICES WILL BE IN THE 105 TO 115 DEGREE RANGE
THROUGH LATE THIS AFTERNOON. OVERNIGHT TEMPERATURES WILL ONLY DROP
INTO THE MID 70S TO LOWER 80S. THE EXCESSIVE HEAT WARNING WILL
CONTINUE THROUGH THE OVERNIGHT HOURS ALONG AND SOUTHEAST OF A
MORRIS COUNTY TO JEFFERSON COUNTY LINE.

THUNDERSTORMS CHANCES EXIST IN PORTIONS OF NORTH CENTRAL KANSAS
LATE THIS AFTERNOON AND FOR MAINLY NORTH CENTRAL AND NORTHEAST
KANSAS TONIGHT. STRONG STRAIGHT LINE WINDS AND LOCALLY HEAVY RAIN
COULD OCCUR WITH THESE STORMS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THE EXCESSIVE HEAT WARNING CONTINUES THROUGH THURSDAY AFTERNOON
FOR THE COUNTIES ALONG AND SOUTHEAST OF A MORRIS COUNTY TO
JEFFERSON COUNTY LINE. HEAT INDICES IN THIS AREA ON THURSDAY WILL
BE IN THE 105 TO 110 RANGE.

THUNDERSTORMS ARE POSSIBLE ACROSS MOST OF THE AREA THURSDAY
THROUGH SATURDAY. THE BEST CHANCE FOR THUNDERSTORMS WILL BE LATE
THURSDAY INTO FRIDAY. THE PRIMARY HAZARDS FROM THESE STORMS WILL
BE DAMAGING WINDS AND HEAVY RAINFALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TOPEKA KS
602 PM CDT WED JUL 27 2011

KSZ035-272330-
DICKINSON-
602 PM CDT WED JUL 27 2011

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL DICKINSON COUNTY...

THROUGH 630 PM CDT...A STRONG THUNDERSTORM WILL MOVE NORTHEAST AT 20
MPH ACROSS PORTIONS OF CENTRAL DICKINSON COUNTY. NATIONAL WEATHER
SERVICE DOPPLER RADAR INDICATED THIS STORM IS CAPABLE OF PRODUCING
STRONG WINDS OF 40 TO 50 MPH...HEAVY RAIN AND FREQUENT LIGHTNING.

SOME LOCATIONS THAT COULD BE AFFECTED INCLUDE ABILENE AND
ENTERPRISE. MOTORISTS ALONG INTERSTATE 70 BETWEEN MILE MARKERS 274
AND 281 COULD ALSO BE AFFECTED.

&&

LAT...LON 3901 9713 3880 9705 3877 9732 3888 9736
TIME...MOT...LOC 2301Z 233DEG 17KT 3884 9729

BLAIR