Flash Flood and Hail in Kansas, July 3, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
352 PM MDT FRI JUL 3 2009

.UPDATE...
348 PM MDT FRI JUL 3 2009

UPDATED FORECAST TO LOCALLY EXPAND THE SEVERE THUNDERSTORM WATCH
AND TO MENTION THE POSSIBILITY OF SEVERE THUNDERSTORMS ACROSS THE
EXPANDED WATCH AREA OVER NEBRASKA.

LOCKHART
&&

.DISCUSSION...
244 PM MDT FRI JUL 3 2009

MAIN FORECAST CHALLENGE IS COVERAGE AND TIMING OF LATE AFTERNOON/EVENING
THUNDERSTORMS THROUGH MONDAY.

FOR THE NEXT SEVERAL DAYS...UPPER WINDS WILL BE FAVORABLE FOR
ADVECTING THUNDERSTORMS WHICH DEVELOP ON THE HIGHER TERRAIN OF
COLORADO EASTWARD ACROSS THE FORECAST AREA. IN ADDITION...NUMEROUS
MINOR SHORT WAVE TROUGHS WILL TRAVERSE THROUGH THE FLOW AND ASSIST
IN THE DEVELOPMENT OF LATE DAY/EVENING THUNDERSTORMS. STARTING
ABOUT TUESDAY OF NEXT WEEK...GUIDANCE INDICATES AN UPPER RIDGE
WILL GAIN A STRONGER FOOTHOLD OVER THE SOUTHERN AND CENTRAL PLAINS WHICH
WILL LIKELY BEGIN TO SUPPRESS STORM DEVELOPMENT TO OUR WEST AS MID
LEVEL TEMPERATURES WARM. TEMPERATURES NEXT WEEK THU-FRI WILL
BEGIN TO CLIMB TO NEAR 100 DEGREES IN RESPONSE TO WARMING MID
LEVEL TEMPERATURES. BOTH THE GFS AND THE ECMWF ADVERTISE
DEVELOPMENT OF THE UPPER RIDGE/HIGH PRESSURE AREA OVER OK/KS BY
WED-THU OF NEXT WEEK...ALTHOUGH AS LATE AS THE 06Z RUN THE GFS WAS
SLOWER IN ITS DEVELOPMENT.  BOTH SEEM TO BE ON A SIMILAR TRACK NOW.

FOR THE IMMEDIATE FUTURE...THE POTENTIAL FOR SEVERE THUNDERSTORMS
TODAY AND TONIGHT IS THE MAIN CONCERN. THE SURFACE MAP SHOWS A LOW
PRESSURE AREA ALONG THE KS/CO BORDER WEST OF TRIBUNE WITH A WARM
FRONT EXTENDING EASTWARD ACROSS SOUTHERN WALLACE...LOGAN AND GOVE
COUNTIES. THIS LOW IS FORECAST TO MOVE NORTHEAST INTO NEBRASKA
OVERNIGHT FOLLOWED BY A TRAILING COLD FRONT. THUNDERSTORMS HAVE
DEVELOPED SOUTH OF THE WARM FRONT FROM SYRACUSE AND TRIBUNE
NORTHEAST TOWARD SCOTT CITY AND OVER TO WAKEENEY AS CONVECTIVE
TEMPERATURES OF 93-95 DEGREES WERE MET WITH DAYTIME HEATING. THE
POTENTIAL EXISTS FOR STRONG DAMAGING WINDS...HAIL WITH THESE
STORMS...AND NEAR AND ADJACENT TO THE WARM FRONT...ISOLATED
TORNADOES. WV SATELLITE AND COMPOSITE RADAR HAVE ALSO SHOWN A
SHORT WAVE TROUGH MOVING EAST ACROSS WYOMING AND COLORADO WHICH
WILL MOVE OUT INTO THE PLAINS THIS EVENING. THAT WILL ALSO BE A
FOCUS FOR THUNDERSTORMS IN ADDITION TO THE WARM FRONT THIS
EVENING. SOME OF THESE STORMS WILL POTENTIALLY PRODUCE STRONG
WINDS AND LARGE HAIL

SAT/SUN/MON...HAVE CONTINUED THE TREND OF LATE DAY AND EVENING
THUNDERSTORMS MOVING IN FROM COLORADO. SURFACE FEATURES SHOULD BE
LACKING IN TERMS OF A THUNDERSTORM FOCUS DURING THIS PERIOD...BUT A
PERSISTENT UPSLOPE LOW LEVEL FLOW ALONG WITH SURFACE DEWPOINTS IN
THE 50S...SHOULD PROVIDE ENOUGH SUPPORT FOR STORM INITIATION ON
THE HIGHER TERRAIN IN COLORADO...WHICH WOULD THEN MOVE EAST.

NO SIGNIFICANT CHANGES MADE TO THE EXTENDED PERIODS OTHER THAN
TWEAKING TEMPS A BIT...AND THE PREVIOUS HOT AND DRY FORECAST WAS
KEPT IN PLACE.

DLF
&&

.AVIATION...
1124 AM MDT FRI JUL 3 2009

FOR THE 18Z TAFS AT KGLD AND KMCK...WILL BE EXPECTING CBS AT KGLD
BY 22Z WITH VCTS AND/OR -TSRA FROM 23Z-04Z AS WEATHER DISTURBANCES
MOVE IN FROM THE SOUTH AND WEST. AFTER 06Z NORTH WINDS WILL USHER
IN THE POSSIBILITY OF MVFR/IFR CIGS BETWEEN 500-1000 FT THROUGH
14Z BEFORE LIFTING/DISSIPATING.

AT KMCK MVFR CIGS OF 1500 FT WILL LIFT TO AROUND 2500 FT WHILE
ALSO BECOMING SCATTERED AS WARM FRONT CONTINUES TO LIFT NORTH.
CBS WITH -TSRA POSSIBLE 00Z-06Z. AS WITH KGLD AM EXPECTING
MVFR/IFR CIGS OF 800 FT WITH SOME POSSIBLE REDUCTIONS IN
VISIBILITY DUE TO STRATUS/FOG. FURTHER DETAILS ON THIS IN FUTURE
TAFS...FOR NOW HAVE GONE WITH SCATTERED TO BROKEN CIGS WITH NO
REDUCTIONS IN VIS.
&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GOODLAND KS
1056 AM MDT FRI JUL 3 2009

COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-041200-
YUMA-KIT CARSON-CHEYENNE CO-CHEYENNE KS-RAWLINS-DECATUR-NORTON-
SHERMAN-THOMAS-SHERIDAN-GRAHAM-WALLACE-LOGAN-GOVE-GREELEY-WICHITA-
DUNDY-HITCHCOCK-RED WILLOW-
1056 AM MDT FRI JUL 3 2009 /1156 AM CDT FRI JUL 3 2009/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EXTREME SOUTHWEST
NEBRASKA...NORTHWEST KANSAS AND EAST CENTRAL COLORADO.

.DAY ONE...THIS AFTERNOON AND TONIGHT

ISOLATED TO SCATTERED STRONG TO SEVERE THUNDERSTORMS PRODUCING
LARGE HAIL...DAMAGING WINDS AND POSSIBLY A TORNADO ARE EXPECTED
IN THE VICINITY OF A WIND SHIFT LINE AFTER 3 PM MDT (4 PM CDT)
FROM CHEYENNE WELLS TO TRIBUNE TO HOXIE AND NORTON.

ADDITIONAL THUNDERSTORMS ARE EXPECTED TO MOVE INTO FAR EASTERN
COLORADO AFTER 3 PM MDT (4 PM CDT) WHICH WILL STEADILY MOVE EAST
INTO NORTHWEST KANSAS AND SOUTHWEST NEBRASKA THROUGH MIDNIGHT.
LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY THREAT. LOCALLY
HEAVY RAIN IS POSSIBLE GENERALLY EAST OF A MCCOOK NEBRASKA TO
COLBY AND TRIBUNE KANSAS LINE TONIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THUNDERSTORMS WILL BE POSSIBLE EACH AFTERNOON AND EVENING THROUGH
MONDAY ACROSS THE TRI-STATE AREA. LIGHTNING IS ALWAYS A HAZARD
WITH ANY THUNDERSTORM.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING.

07/DLF