Special Weather Statement, NWS Topeka, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1140 PM CDT WED AUG 1 2012

...UPDATE TO AVIATION...

.DISCUSSION...

SHORT TERM FORECAST (TONIGHT AND THURSDAY)...

SHORT TERM FORECAST FOR THE REST OF WEDNESDAY HINGES ON THE REMNANTS
FROM WEAK OVERNIGHT SHOWERS PUSHING THROUGH FAR EASTERN KANSAS.
RADAR TRENDS THROUGH 19Z HAVE INDICATED THAT PRECIPITATION FROM
THESE OVERNIGHT SHOWERS HAS SUBSIDED AND ONLY A STRATUS SHIELD
REMAINS. EARLY SURFACE ANALYSIS INDICATED THAT A STRONG OUTFLOW
BOUNDARY PUSHED SOUTHWARD SOUTH OF THE KS/OK BORDER...BUT THROUGHOUT
THE DAY WINDS HAVE SHIFTED BACK TO THE E-SE IN THE WAKE OF THE
DEPARTING CLOUDS. WEST OF THE PRECIPITATION SHIELD TEMPERATURES HAVE
ALREADY RISEN BACK INTO THE LOWER 100S...BUT DUE TO STRONG MIXING
AND A VERY DRY LOW AND MID LEVEL ATMOSPHERIC COLUMN SURFACE TDS HAVE
DROPPED TO THE UPPER 50S TO LOWER 60S IT MAY BE TOUGH FOR HEAT
INDICES TO CLIMB BACK INTO THE 100 TO 105 RANGE...ALTHOUGH IT IS
CONCEIVABLE THAT TEMPERATURES WILL STILL APPROACH THE 100 DEGREE
THRESHOLD BEFORE THE DAY IS COMPLETELY DONE SO WILL LET THE
ADVISORY CONTINUE THROUGH THE HOTTEST HOURS OF THE DAY THIS PM. FOR
THE OVERNIGHT HOURS MODELS HAVE STRUGGLED SOMEWHAT WITH THE
RESOLUTION OF EMBEDDED SHORTWAVE TROUGHS WITHIN THE BETTER FLOW
NORTH OF THE MID/UPPER RIDGE. SINCE THE RIDGE REMAINS WELL
ESTABLISHED TO THE SOUTHWEST OF THE FORECAST AREA...GOOD MID TO
UPPER LEVEL FLOW OF 20 TO 30 KTS MEANS WE COULD SEE A CHANCE FOR
SHOWERS AND THUNDERSTORMS OVERNIGHT AS AN EMBEDDED WAVE COMES OFF
THE E. COLORADO PLAINS. CERTAINTY SURROUNDING OVERNIGHT RAIN IS
RATHER LOW...BUT A CHANCE FOR PRECIPITATION CERTAINLY DOES EXIST
FOR PORTIONS OF NORTH CENTRAL...NORTHEAST AND EAST CENTRAL KANSAS
FOR THE EARLY MORNING HOURS ON THURSDAY. SHOULD OVERNIGHT SHOWERS
FORM ACROSS CENTRAL KANSAS THE MID LEVEL STRATUS SHIELD MAY
PERSIST IN THE AREA THROUGH NOON...SIMILARLY TO WEDNESDAY...WHICH
MAY HINDER A RAPID INCREASE IN TEMPERATURES THROUGHOUT THE DAY.
WILL GO WITH A BIT OF A PERSISTENCE FORECAST THAT LEANS TOWARD THE
MET GUIDANCE...BUT THESE HIGHS MAY BE SLIGHTLY LOWER SHOULD CLOUDS
HOLD INTO THE AREA LONGER IN THE DAY.

JL

THURSDAY NIGHT-NEXT WEDS...

PATTERN OF WEAK SHORTWAVE TROUGHS OVER THE CENTRAL PLAINS WITHIN
THE MODEST FLOW ALOFT WILL PERSIST THROUGH FRI. TRICKY LOWER
CONFIDENCE FORECAST FOR PRECIP CHANCES THURSDAY EVENING AS ANOTHER
WEAK VORT MAX TRACKS ACROSS NORTHEAST KANSAS INTO MISSOURI. DECENT
WARM AIR ADVECTION ALOFT COUPLED WITH ISENTROPIC ASCENT ON THE
310K AND 315K SURFACES ESPECIALLY OVER THE EAST CENTRAL COUNTIES
MAY BE ABLE TO SUPPORT OR ENHANCE ANY SHOWERY ACTIVITY THROUGH THE
OVERNIGHT PERIOD. WITH THE POTENT RIDGE CENTERED TO THE SOUTH
HIGHS ON FRIDAY APPROACH THE UPPER 90S TO LOWER 100S. WITH THE
EASTERLY FLOW INCREASING THE DEWPOINT VALUES AREA WIDE IN THE
MIDDLE TO UPPER 60S...HEAT INDICES COULD AGAIN REACH ADVISORY
CRITERIA AROUND 105 DEGREES.

TEMPORARY RELIEF FROM THE HEAT AND HIGHER RAIN CHANCES STILL LOOK TO OCCUR
FRI NIGHT-SAT AS A COLD FRONT DROPS SOUTHEASTWARD FROM NEBRASKA.
SLIGHTLY INCREASED FRONTAL POSITION FURTHER SOUTH DURING THE
AFTERNOON PERIOD AS THE LATEST GUIDANCE ACCELERATES THE FRONT
TOWARDS THE FAR EAST CENTRAL AND SOUTHEAST COUNTIES OF THE CWA BY
EARLY EVENING. HIGHS WILL ALSO BE DEPENDENT ON THE FRONTAL
POSITION DURING THE PEAK HEATING HOURS. AT THIS TIME LOWER 90S ARE
EXPECTED FOR THE COUNTIES NEAR THE NEBRASKA BORDER...SPANNING TO
NEAR 100 DEGREES OVER LYON...COFFEY AND ANDERSON COUNTIES.

ANY RELIEF FROM HOT TEMPS WILL BE SHORT-LIVED AS HTS RISE AND THE
RIDGE BEGINS TO BUILD BACK INTO THE PLAINS NEXT WEEK. HOT AND
MAINLY DRY WEATHER SHOULD PERSIST INTO WEDS WHEN ANOTHER WEAK COLD
FRONT IS FCST TO DROP INTO THE AREA.

BOWEN

&&

.AVIATION...

MAIN CONCERN FOR THE TAFS WILL BE THE TIMING AND AREAL COVERAGE OF
CONVECTION AS IT MOVES ACROSS NORTHEAST KANSAS. CIGS EXPECTED TO
BE VFR THROUGH THE PERIOD BUT MVFR VSBYS ARE POSSIBLE WITH TSRA.
CONVECTION SHOULD MOVE EAST OF THE TERMINALS BY 16Z. HAVE
MAINTAINED A MENTION OF VCTS ATTM.

53

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
1259 PM CDT WED AUG 1 2012

KSZ008>012-020>024-026-034>040-054>056-058-059-021800-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
1259 PM CDT WED AUG 1 2012

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

HEAT INDEX VALUES WILL RANGE FROM 100 TO 105 DEGREES THIS
AFTERNOON ACROSS MUCH OF THE AREA.

THERE IS A CHANCE FOR THUNDERSTORMS ACROSS NORTH CENTRAL AND
NORTHEAST KANSAS TONIGHT...WITH A SLIGHT CHANCE OF THUNDERSTORMS
ACROSS EAST CENTRAL KANSAS.

THE RANGELAND FIRE DANGER WILL BE VERY HIGH ACROSS PARTS OF EAST
CENTRAL AND NORTH CENTRAL KANSAS THIS AFTERNOON.

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

THUNDERSTORMS ARE POSSIBLE THURSDAY THROUGH SATURDAY NIGHT. THE
BETTER CHANCES OF STORMS APPEARS TO BE SATURDAY AFTERNOON AS A
COLD FRONT MOVES THROUGH.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TOPEKA KS
108 AM CDT THU AUG 2 2012

KSZ008-020-020700-
CLOUD-REPUBLIC-
108 AM CDT THU AUG 2 2012

...SIGNIFICANT WEATHER ADVISORY FOR REPUBLIC AND NORTHWESTERN CLOUD
COUNTIES...

THROUGH 200 AM CDT...STRONG OUTFLOW WINDS OF 40 TO 50 MPH FROM
THUNDERSTORMS TO THE NORTH AND WEST OF REPUBLIC COUNTY WILL MOVE
SOUTHEAST ACROSS  REPUBLIC AND NORTHWESTERN CLOUD COUNTIES. NATIONAL
WEATHER SERVICE DOPPLER RADAR INDICATED THUNDERSTORMS JUST BEHIND
THE STRONGER WINDS WILL THEN MOVE ACROSS NORTHERN CLOUD AND WESTERN
REPUBLIC COUNTIES PRODUCING LOCALLY HEAVY RAINFALL AND MORE GUSTY
WINDS. SOME LOCATIONS THAT COULD BE AFFECTED INCLUDE
BELLEVILLE...MUNDEN...CUBA...AGENDA...NARKA...JAMESTOWN AND
CONCORDIA.

&&

LAT...LON 4000 9737 3967 9738 3954 9793 4000 9794
TIME...MOT...LOC 0604Z 270DEG 22KT 3995 9774

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TOPEKA KS
151 AM CDT THU AUG 2 2012

KSZ008-009-020-020745-
CLOUD-REPUBLIC-WASHINGTON-
151 AM CDT THU AUG 2 2012

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN REPUBLIC...NORTHEASTERN
CLOUD AND WASHINGTON COUNTIES...

THROUGH 245 AM CDT...A LINE OF STRONG THUNDERSTORMS WILL MOVE EAST AT
40 MPH ACROSS PORTIONS OF EASTERN REPUBLIC...NORTHEASTERN CLOUD AND
WASHINGTON COUNTIES. NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THESE STORMS ARE CAPABLE OF PRODUCING STRONG WINDS IN EXCESS OF 50
MPH...TORRENTIAL RAINFALL AND FREQUENT LIGHTNING. SOME LOCATIONS THAT
COULD BE AFFECTED INCLUDE CLYDE...CUBA...AGENDA...NARKA...MAHASKA...
HADDAM...PALMER...MORROWVILLE...LINN...WASHINGTON...GREENLEAF...
HOLLENBURG...BARNES...BELLEVILLE AND HANOVER.

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

&&

LAT...LON 4000 9680 3966 9681 3952 9757 4000 9774
TIME...MOT...LOC 0650Z 258DEG 34KT 4012 9764 3985 9754
          3963 9749

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TOPEKA KS
155 AM CDT THU AUG 2 2012

KSZ020-021-034-020745-
CLAY-CLOUD-OTTAWA-
155 AM CDT THU AUG 2 2012

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN OTTAWA...WESTERN CLAY
AND CLOUD COUNTIES...

THROUGH 245 AM CDT...A LINE OF STRONG THUNDERSTORMS WILL MOVE EAST AT
30 MPH ACROSS PORTIONS OF NORTHERN OTTAWA...WESTERN CLAY AND CLOUD
COUNTIES. NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THESE
STORMS ARE CAPABLE OF PRODUCING STRONG WINDS IN EXCESS OF 50 MPH...
TORRENTIAL RAINFALL AND FREQUENT LIGHTNING. SOME LOCATIONS THAT COULD
BE AFFECTED INCLUDE GLASCO...DELPHOS...MINNEAPOLIS...CONCORDIA...
CONCORDIA AIRPORT...WELLS...AURORA...MILTONVALE AND CLYDE.

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

&&

LAT...LON 3963 9792 3963 9737 3957 9737 3955 9735
      3913 9734 3913 9737 3909 9737 3910 9793
TIME...MOT...LOC 0655Z 277DEG 24KT 3960 9790 3919 9792