Severe Thunderstorm Warning 170, NWS Topeka, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KANSAS
415 PM CDT TUE AUG 19 2003

...THUNDERSTORM CHANCES AND HEAT ARE THE MAIN FORECAST CHALLENGES
THROUGH THURSDAY....

THIS MORNINGS UPPER AIR ANALYSIS SHOWED A CLOSED LOW OVER EASTERN
WY/WESTERN NE. A BROAD RIDGE WAS LOCATED ACROSS THE GREAT LAKE
STATES AND LOWER MS RIVER VALLEY. THE STRONGEST UPPER LEVEL JET WAS
LOCATED ACROSS CENTRAL CANADA. THE 18Z SURFACE MAP SHOWED AN OUTFLOW
BOUNDARY ACROSS EASTERN NEBRASKA WHILE A LEE SURFACE TROUGH
EXTENDED FROM WESTERN NEBRASKA SOUTHWARD THROUGH EASTERN CO.
HIGH-BASED THUNDERSTORMS WERE DEVELOPING ACROSS SOUTHWEST KANSAS.

CONVECTIVE TEMPERATURES WILL BE REACHED LATE THIS AFTERNOON ACROSS
THE FORECAST AREA. THUNDERSTORMS WILL DEVELOP ACROSS THE NORTHERN
AND WESTERN COUNTIES LATE THIS AFTERNOON AND EVENING. THE NUMEROUS
COVERAGE OF THUNDERSTORMS SHOULD REMAIN NORTH OF THE FORECAST AREA
ALONG THE SURFACE OUTFLOW BOUNDARY OVER EASTERN NEBRASKA. AT THIS
TIME I WILL KEEP SCATTERED POPS ACROSS THE WESTERN AND NORTHERN
COUNTIES WITH ISOLATED POPS ACROSS THE EAST-CENTRAL AND SOUTHERN
COUNTIES. VEERING AND INCREASING WIND PROFILES WITH HEIGHT COMBINE
WITH  CAPES AT OR ABOVE 1800 J/KG MAY ALLOW A FEW THUNDERSTORMS TO
REACH SEVERE LIMITS. THE PRIMARY THREAT WILL BE LARGE HAIL AND
DAMAGING OUTFLOW WINDS.

THE UPPER LOW OVER WESTERN NEBRASKA WILL BECOME AN OPEN WAVE AS IT
LIFTS NORTHEAST INTO MINNESOTA BY WEDNESDAY AFTERNOON. THE SOUTHERN
EXTENT OF THE UPPER LEVEL TROUGH AXIS WILL MOVE ACROSS EASTERN
KANSAS WEDNESDAY AFTERNOON. SYNOPTIC SCALE LIFT AHEAD OF THE UPPER
LEVEL TROUGH AXIS WILL IMPROVE THE ENVIRONMENT FOR THUNDERSTORM
DEVELOPMENT ACROSS EASTERN KANSAS WEDNESDAY AFTERNOON. A SURFACE
TROUGH WILL ALSO MOVE EAST ACROSS THE FORECAST AREA TOMORROW
AFTERNOON. SURFACE CONVERGENCE AHEAD OF THE SURFACE TROUGH AXIS
SHOULD BE SUFFICIENT FOR SCATTERED THUNDERSTORMS TO DEVELOP DURING
THE AFTERNOON HOURS ACROSS THE WESTERN COUNTIES. THE THUNDERSTORMS
WILL MOVE EAST ACROSS THE REMAINDER OF THE AREA DURING THE LATE
AFTERNOON AND EVENING HOURS. HIGH TEMPERATURES ON WEDNESDAY WILL
REACH INTO THE UPPER 90S TO AROUND 100 DEGREES. DEW POINTS AHEAD OF
THE TROUGH AXIS WILL BE IN THE UPPER 60S TO AROUND 70 DEGREES...THUS
HEAT INDEX VALUES WILL ONCE AGAIN BE IN THE 102 TO 108 DEGREE RANGE.
LOW-LEVEL COLD AIR ADVECTION ON THE WEST SIDE OF THE UPPER LEVEL
TROUGH OVER MINNESOTA WILL CAUSE A COLD FRONT TO MOVE SOUTH ACROSS
EASTERN KANSAS ON THURSDAY. THERE MAY BE ANOTHER SLIGHT CHANCE FOR
THUNDERSTORMS ALONG AND AHEAD OF THE SURFACE COLD FRONT THURSDAY
AFTERNOON. SLIGHTLY COOLER AIR WILL MOVE SOUTH ACROSS EASTERN KANSAS
ON FRIDAY. HIGH TEMPERATURES ON FRIDAY WILL BE IN THE LOWER TO MID
90S.

THE EXTENDED RANGE MODELS SHOW THE UPPER LEVEL RIDGE INTENSIFYING
ACROSS THE CENTRAL PLAINS EARLY NEXT WEEK. EXPECT DRY CONDITIONS
THROUGH THE WEEKEND INTO EARLY NEXT WEEK. HIGH TEMPERATURES WILL
WARM INTO THE MID AND UPPER 90S SUNDAY THROUGH NEXT TUESDAY. THE
UKMET AND ECMWF MODEL SOLUTION AMPLIFIES THE UPPER LEVEL RIDGE MORE
SO THAN THE GFS. IF THE UKMET AND ECMWF SOLUTIONS VERIFY HIGH
TEMPERATURES WILL BE A CATEGORY HIGHER.

.TOP...KSZ08-12>20-24>26>34-39. SEVERE THUNDERSTORM WATCH IN EFFECT
UNTIL 900 PM CDT.

KSZ008>012-020>024-026-034>040-054>056-058-059-201000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
458 PM CDT TUE AUG 19 2003

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

.DAY ONE...THIS EVENING AND TONIGHT

SCATTERED THUNDERSTORMS WILL CONTINUE NORTH AND WEST OF A SABETHA TO
MANHATTAN TO ABILENE LINE DURING THE EVENING HOURS. A FEW OF THESE
THUNDERSTORMS MAY REACH SEVERE LIMITS PRODUCING LARGE
HAIL...DAMAGING WIND GUSTS...DANGEROUS LIGHTNING AND BRIEF HEAVY
RAINFALL. ISOLATED THUNDERSTORMS MAY DEVELOP ACROSS THE REMAINDER OF
THE REGION THIS EVENING. THE SEVERE THUNDERSTORM THREAT WILL
DECREASE AFTER SUNSET.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A CHANCE FOR THUNDERSTORMS WILL CONTINUE ACROSS THE REGION WEDNESDAY
AND THURSDAY.

HOT TEMPERATURES WILL ALSO CONTINUE WEDNESDAY WITH AFTERNOON HEAT
INDICES OF 102 TO 107 EXPECTED.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS MAY BE NEEDED THIS EVENING NORTH AND WEST OF A COUNCIL
GROVE TO HARVEYVILLE TO OSKALOOSA LINE.

&&

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB PAGE:
   HTTP://WWW.CRH.NOAA.GOV/TOP  (ALL LOWER CASE)

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TOPEKA KS
554 PM CDT TUE AUG 19 2003

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0538 PM    HANOVER                   KS    60 MPH TSTM GUST
08/19/03   WASHINGTON