Flash Flood and Flood in Kansas, September 24 to 25, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
212 PM MDT WED SEP 24 2008

.SYNOPSIS...
122 PM MDT WED SEP 24 2008

ANALYSIS OF WATER VAPOR IMAGERY SHOWS A WEAK SHORTWAVE TROUGH
DEPARTING THE AREA AFTER KICKING OFF A FEW WEAK THUNDERSTORMS OVER
SOUTHEAST COLORADO EARLIER TODAY. FAIRLY ZONAL MID/UPPER FLOW IN
PLACE ACROSS THE CENTRAL HIGH PLAINS WITH A NEGATIVELY TILTED
SHORTWAVE TROUGH SLIDING EASTWARD ACROSS THE NORTHERN PLAINS AND
PRAIRIE PROVINCES OF CANADA. ANOTHER SHORTWAVE TROUGH WAS
BEGINNING TO IMPACT THE PACIFIC NORTHWEST. AT THE SURFACE...A WEAK
AREA OF LOW PRESSURE WAS DEVELOPING OVER SOUTHEAST COLORADO. THE
COLD FRONT WHICH PUSHED THROUGH THE AREA ON TUESDAY HAS STARTED A
SLOW PROGRESSION BACK NORTHWARD AS A DIFFUSE WARM FRONT.

FOLTZ
&&

.DISCUSSION...
122 PM MDT WED SEP 24 2008

PRIMARY FORECAST CONCERNS REVOLVE AROUND PRECIP CHANCES THIS
EVENING AND THEN AGAIN SUNDAY INTO MONDAY.

AS MENTIONED ABOVE...DIFFUSE WARM FRONT PUSHING NORTH OVER THE CWA
WITH A WEAK AREA OF SURFACE LOW PRESSURE DEVELOPING OVER SOUTHEAST
COLORADO. SOUTHERLY TO SOUTHEASTERLY FLOW HAS ALLOWED FOR AN
INCREASE IN BOUNDARY LAYER MOISTURE. 315K GFS ISENTROPIC SURFACE
SHOWS AN INCREASE IN MOISTURE TRANSPORT THIS AFTERNOON WITH BEST
LIFT FOCUSED OVER THE EASTERN PORTIONS OF THE GLD CWA BY 00Z. BY 06Z
THURSDAY...GREATEST FORCING FOR ASCENT SHIFTS EAST OF THE AREA SO
HAVE POPS ENDING AT THIS TIME. WITH 800-1000 J/KG ML CAPE IN
PLACE...CANT RULE OUT ISOLATED SEVERE BUT THREAT SHOULD BE
LIMITED AS FLOW ALOFT IS WEAK.

WILL SEE TEMPS WARM A DEGREE OR TWO ON THURSDAY AS H85 TEMPS JUMP
A DEGREE OR TWO C ACROSS THE AREA. WITH SUBSIDENCE IN PLACE...WILL
SEE GENERALLY CLEAR SKIES. WARM UP WILL CONTINUE ON FRIDAY WITH
MOST LOCATIONS APPROACHING IF NOT EXCEEDING THE 90 DEGREE MARK AS
H85 TEMPS WARM TO 25 C.

WEAK COLD FRONT MOVES THROUGH THE REGION FRIDAY NIGHT INTO SATURDAY
MORNING PROVIDING LITTLE MORE THAN A SHIFT TO NORTHERLY WINDS.
WEAK UPGLIDE IS NOTED ON THE 310K NAM ISENTROPIC SURFACE BUT
MOISTURE IS LACKING LEADING TO CONDENSATION PRESSURE DEFICITS OF
AROUND 200MB. HAVE THROWN IN SILENT POPS TIED TO THE PASSAGE OF
THE COLD FRONT IN THE EVENT MODELS ARE UNDER ESTIMATING MOISTURE
RETURN BUT CONFIDENCE IN PRECIPITATION IS LOW AT THIS TIME.

MID/UPPER LEVEL PATTERN STARTS TO SHIFT BY SUNDAY MORNING WITH A
STRONG CLOSED LOW DROPPING SOUTH OUT OF SASKATCHEWAN AND MANITOBA INTO
THE NORTHERN PLAINS. LEAD SHORTWAVE TROUGH AND A SURFACE COLD
FRONT WILL IMPACT THE GLD CWA SUNDAY INTO THE DAY ON MONDAY. HAVE
MAINTAINED LOW SLIGHT CHANCE POPS STARTING SUNDAY MORNING. BEST
FORCING FOR ASCENT WILL BE OUT OF THE AREA BY AROUND 12Z MONDAY
BASED ON LATEST NUMERICAL GUIDANCE BUT STRONG CAA WILL CONTINUE.
H85 TEMPS DROP TO THE LOW TEENS RESULTING IN SURFACE TEMPS IN THE
MID 70S.

THE MID/UPPER LEVEL CLOSED LOW GETS HUNG UP OVER THE MIDDLE
MISSISSIPPI RIVER VALLEY ON TUESDAY BEFORE BEGINNING A SLOW
EASTWARD TREK INTO THE OHIO VALLEY AND LOWER GREAT LAKES ON
WEDNESDAY. AREA WILL CONTINUE TO BE UNDER THE INFLUENCE OF CAA
THROUGH THE END OF THE FORECAST PERIOD. MODELS GENERALLY TEND TO
BE TOO FAR EAST WITH DEEP CLOSED LOWS THIS FAR OUT SO WONT BE
SURPRISED IF MODELS TREND THIS FEATURE FURTHER WEST IN FUTURE
RUNS. BOTTOM LINE...WILL CARRY LOW 70S TEMPS OVER THE EASTERN
PORTION OF THE CWA BUT THIS WILL LIKELY NEED TO BE TRIMMED EVEN
FURTHER IF A FURTHER WESTWARD SOLUTION VERIFIES.

FOLTZ
&&

.AVIATION...
1145 AM MDT WED SEP 24 2008

FOR THE 18Z TAFS...VFR WILL PREVAIL THROUGH MUCH OF THE 24 HOUR
PERIOD. WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED AFTER 21-22Z
THEREAFTER WITH POSSIBLE MVFR BEFORE ACTIVITY MOVES NORTHEAST OF THE
AREA AFTER 05-07Z. EASTERLY WINDS AT 10 TO 20 MPH WILL VEER AND
BECOME SOUTHERLY BY SUNRISE ON THURSDAY.

MCGUIRE
&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GOODLAND KS
1050 AM MDT WED SEP 24 2008

COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-251200-
YUMA-KIT CARSON-CHEYENNE CO-CHEYENNE KS-RAWLINS-DECATUR-NORTON-
SHERMAN-THOMAS-SHERIDAN-GRAHAM-WALLACE-LOGAN-GOVE-GREELEY-WICHITA-
DUNDY-HITCHCOCK-RED WILLOW-
1050 AM MDT WED SEP 24 2008 /1150 AM CDT WED SEP 24 2008/

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON AS
LOW LEVEL MOISTURE RETURNS NORTH ALONG A DIFFUSE WARM FRONT.
ALTHOUGH WIDESPREAD SEVERE WEATHER IS NOT EXPECTED, THE STRONGEST
STORMS WILL BE CAPABLE OF PRODUCING LARGE HAIL AND STRONG WINDS. A
FEW THUNDERSTORMS MAY LINGER INTO THE OVERNIGHT HOURS...HOWEVER
WIDESPREAD SEVERE WEATHER IS NOT EXPECTED.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

A COLD FRONT WILL ARRIVE LATE SUNDAY WITH WIDELY SCATTERED
THUNDERSTORMS POSSIBLE ACROSS THE TRI-STATE AREA THROUGH MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GOODLAND KS
345 PM MDT WED SEP 24 2008

KSZ014-242215-
THOMAS-
445 PM CDT WED SEP 24 2008

...THE NATIONAL WEATHER SERVICE IN GOODLAND HAS ISSUED A SIGNIFICANT
WEATHER ALERT FOR THOMAS COUNTY IN NORTHWEST KANSAS...

AT 441 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR HALFORD...AND MOVING NORTHEAST AT 8 MPH.

PENNY TO NICKEL SIZE HAIL...AND WINDS TO 50 MPH ARE EXPECTED WITH
THIS STORM.

LOCKHART