Severe Thunderstorm Warning 309, NWS Dodge City, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
338 PM CDT MON AUG 10 1998

THE MAIN QUESTION OF THE DAY IS WHEN MORE CONVECTION WILL FIRE.

CONVECTION ORGANIZED IN A SCATTERED LINE ALONG THE ROCKY MTN
RANGE...AND SOME OF THESE STORMS SHOULD HOLD TOGETHER AS THEY
DRIFT SOUTHEAST INTO W KANSAS THIS EVENING.  ATTM...AN ISOLATED
STORM FORMED AROUND 1950Z IN NW SCOTT COUNTY.  THINK THIS LONE STORM
IS ALONG A SMALL OUTFLOW BOUNDARY FROM MORNING CONVECTION IN
GOVE/SHERIDAN COUNTY AREA.

CHOOSING A BEST MODEL TRICKY AS AVN INITIALIZED BEST OVERALL.
BUT...LOOKING AT WELL ORGANIZED SHORT WAVE IN CENTRAL MONTANA IN WV
SATL LOOP...ETA BEST MODEL WITH THAT FEATURE.  UPPER LEVEL FLOW IS
SO WEAK THAT MODEL WHICH IDENTIFIES THESE OBVIOUS FEATURES WIN
OUT...ESPECIALLY WITH TIMING ISSUES.  SO MUCH LOW AND MID LEVEL
MOISTURE RESIDUAL THAT ANY MINOR DISTURBANCE WILL EASILY TRIGGER
RW/TRWS.  DO NOT SEE MUCH POTENTIAL FOR SEVERE...AS LAST NIGHT/S
CONVECTION DESTABILIZED THE AIR COLUMN AND ADVECTED COOLER AIR INTO
MID LEVELS.  HOWEVER...HEAVY RAIN A POSSIBILITY DUE TO SLOW STEERING
FLOW AND GOBBS OF LOWER LEVEL H20.  WILL NOT MENTION PSBL HVY RAIN
THOUGH...AS THINK IT WILL BE VERY LOCALIZED.  WILL ONLY MENTION SLGT
CHC TRW FOR TUESDAY MORNING...THEN REINTRODUCE LOW POPS WED AS SHORT
WAVE IN MONTANA MENTIONED ABOVE COMES INTO PLAY BY SLIDING SEWD
THROUGH CENTRAL/EASTERN KANSAS.

FAVORED FAN/ETA COMPROMISE FOR TEMPS.  WEDNESDAY SHOULD BE LITTLE
WARMER THAN TUES WITH MORE SUN AROUND.

EXTENDED...LITTLE SIGNIFICANT CHANGE IN THE FLOW REGIME OVER THE
CENTRAL PLAINS SEEMS LIKELY FOR THE NEXT FEW DAYS.  NUMEROUS MINOR
WAVES EMBEDDED IN THE FLOW OVER THE GULF OF ALASKA WILL MOVE OVER
THE WESTERN UNITED STATES RIDGE AND WALLOW SLOWLY SOUTHEASTWARD INTO
THE PERSISTENT LONG WAVE TROUGH OVER THE MISSISSIPPI VALLEY.  COOL
HIGH PRESSURE SHOULD CONTINUE OVER THE MIDWEST WITH WEAK UPSLOPE
FLOW ACROSS THE HIGH PLAINS.  TIMING OF THE MINOR WAVES EVEN IN THE
SHORT TERM IS DIFFICULT...AND ATTEMPTS TO BE HIGHLY SPECIFIC IN THE
EXTENDED PERIOD IS AN EXERCISE IN FUTILITY.  UPPER LEVEL FLOW SHOULD
BE HIGHLY MERIDIONAL AT LEAST THROUGH FRIDAY...AND MUCH OF THE
CONVECTION WHICH BLOSSOMS ALONG THE LEE SLOPES OF THE ROCKIES MAY
HAVE A DIFFICULT TIME PROPAGATING VERY FAR EASTWARD INTO THE PLAINS
STATES.  NEVERTHELESS...DESTABILIZATION WITH THE MINOR WAVES MAY BE
SUFFICIENT TO SUPPORT SCATTERED THUNDERSTORMS THROUGH THE PERIOD.

THE LIMITED MRF DATA AVAILABLE FOR THIS FORECAST CYCLE APPEARS TO BE
MORE IN AGREEMENT WITH THE ECMWF SOLUTION THAN THE UKMET...AND THE
WEAKER LOW LEVEL FLOW REGIME SUGGESTED BY THE ECMWF/UKMET SEEMS
REASONABLE GIVEN THE MERIDIONAL FLOW ALOFT.  SUFFICIENT FLOW
PERPENDICULAR TO THE NORTHERN ROCKIES TO SUPPORT A REASONABLE
PRESSURE GRADIENT IN THE LEE OF THE ROCKIES MAY DEVELOP OVER THE
WEEKEND. GUIDANCE TEMPERATURES HAVE COME DOWN TO REASONABLE
LEVELS AND WILL BE ADJUSTED ONLY A FEW DEGREES FOR THE EXTENDED
PERIOD.

PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECASTS ARE
CONTAINED WITHIN THE TOPZFPDDC.

DDC 067/086 065/088 062 321
GCK 066/087 064/088 061 321
EHA 065/088 063/089 060 421
LBL 068/087 066/089 063 321
HYS 065/085 062/088 060 321
P28 070/090 068/092 065 221

.DDC...NONE.

BURKE/01