Flash Flooding and Hail in Kansas, September 13, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
330 PM CDT THU SEP 13 2001

FORECAST CHALLENGE WILL BE TEMPERATURES AND THE CHANCE FOR
THUNDERSTORMS.  UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY LOOP
INDICATING A WEAK SHORTWAVES OVER THE INTERMOUNTAIN REGION THIS
MORNING.  STRONGER WAVE IN THE UPPER LEVEL WESTERLIES WAS MOVING
THROUGH THE GREAT LAKES REGION ATTM.  IN THE LOWER LEVELS, THE
850 MB LEVEL SHOWED A GOOD BAROCLINIC ZONE ACROSS WYOMING,
NEBRASKA AND IOWA. HIGHER 850 MB DEWPOINTS WERE POOLING ALONG THE
BAROCLINIC ZONE AND A NARROW RIBBON OF 12-14 DEG DEWPOINT AIR
CONTINUED OVER WESTERN KANSAS INTO THE TEXAS PANHANDLE.  AT THE
SURFACE A NEARLY STATIONARY COLD FRONT WAS LOCATED ALONG THE
KANSAS/NEBRASKA BORDER THEN BACK INTO SOUTHEAST WYOMING.  A SURFACE
LOW PRESSURE TROUGH WAS LOCATED OVER EASTERN COLORADO.

MODELS OFFERING SIMILAR SOLUTIONS WITH SOME MINOR VARIATIONS THROUGH
36 HOURS.  FRONT MAY MAKE SOME SOUTHWARD PROGRESSION BUT SHOULD STAY
TO THE NORTH OF MY ZONES TONIGHT.  WEAK UPPER WAVE MOVING ACROSS
SOUTHERN COLORADO THIS AFTERNOON SHOULD BRING A CHANCE FOR
THUNDERSTORMS TO THE AREA TONIGHT WITH THE BEST CHANCES IN THE WEST.
DONT THINK THE SOUTHEAST PART OF THE CWA WILL SEE ANY STORMS TONIGHT
AND WILL TAPER OFF CHANCES FARTHER EAST. ON FRIDAY, THE SHORTWAVE
WILL BE MOVING ACROSS WESTERN KANSAS. SHOULD SEE AT LEAST PARTLY
SUNNY SKIES ALONG WITH SCATTERED TO WIDELY SCATTERED THUNDERSTORMS
DURING THE DAY.  TEMPERATURES WILL BE A BIT TRICKY DUE TO VARYING
AMOUNTS OF CLOUD COVER BUT BELIEVE THAT HIGHS WILL BE TOPPING OUT
IN THE LOW TO MID 80S, AND POSSIBLY IN THE UPPER 80S IN A FEW
LOCATIONS, DUE TO THE FACT THAT WE WILL BE REMAINING IN THE WARM
SECTOR.  MODELS DIVERGE IN THE 48-60 HOUR TIME PERIOD WITH
THE TIMING OF THE FRONT AS IT MOVES SOUTH ACROSS THE HIGH PLAINS.
WILL GO WITH THE ETA SOLUTION OF MOVING THE FRONT SOUTH ACROSS THE
CWA DURING THE DAY.  WILL CONTINUE WITH CHANCE POPS AND TREND
TEMPERATURES FROM WARMEST IN THE SOUTHEAST WITH COOLER TEMPERATURES
IN THE NORTHERN AND WESTERN SECTIONS OF THE CWA.

EXTENDED DISCUSSION...

ONE BIG QUESTION IN THIS PACKAGE IS HOW FAR SOUTH THE FRONT WILL
MAKE IT SATURDAY NIGHT. THE AVIATION IS MUCH FURTHER SOUTH AND KEEPS
THE THUNDERSTORMS IN THE TEXAS PANHANDLE...WHILE THE 84 HR ETA
STALLS THE FRONT ALONG THE OKLAHOMA BORDER AND BREAKS OUT A LARGE
AREA OF THUNDERSTORMS OVER SW KS. MOST OF THE THUNDERSTORM ACTIVITY
SHOULD GET SHUNTED TO THE SOUTH AND WEST ON SUNDAY...BUT GIVEN THE
UNCERTAINTY WE WILL INTRODUCE A SLIGHT CHANCE OF THUNDERSTORMS.
ANOTHER POTENT UPPER LEVEL SYSTEM IS ADVERTISED BY THE UKMET/AVN TO
ADVANCE ACROSS THE ROCKIES BY TUESDAY AND ACROSS THE PLAINS BY
WEDNESDAY. AHEAD OF THIS SYSTEM AMPLE MOISTURE SHOULD BE IN PLACE.
THE EUROPEAN IS THE ODD MODEL OUT AND SHOWS NO UPPER LOW AT ALL.
MODELS DIFFER SOMEWHAT ON STRENGTH OF THE NORTHERN STREAM SYSTEM. IF
THIS SYSTEM DIGS MORE...THEN THE WESTERN SYSTEM WOULD GET SHUNTED TO
THE SOUTH ACROSS THE SOUTHERN PLAINS...AND A STRONGER COLD FRONT
WOULD MOVE DOWN THE PLAINS. IF THE UKMET SOLUTION IS CORRECT WITH A
WEAKER NORTHERN STREAM SYSTEM...THEN ANY COLD FRONT WOULD BE WEAKER
AND SLOWER TO ARRIVE. WE WILL GO WELL ABOVE AVNMOS TEMPERATURES FOR
MOST OF THE EXTENDED PACKAGE AS THIS OUTPUT HAS BEEN BIASED ON THE
COOL SIDE FOR SEVERAL MONTHS. WE SHOULD SEE A NICE WARMUP TUESDAY
AHEAD OF THE WESTERN SYSTEM.

PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECASTS ARE
CONTAINED WITHIN THE DODGE CITY ZONE FORECAST.

DDC 066/085 062/080 054 232
GCK 064/084 060/079 052 232
EHA 061/087 059/078 051 312
LBL 063/085 060/081 053 232
HYS 064/083 061/077 050 235
P28 063/085 064/086 056 032

.DDC...NONE.

GERARD/FINCH