Severe Thunderstorm Warning 308, NWS Dodge City, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
321 PM CDT FRI AUG 20 1999

FORECAST CHALLENGE IS PCPN TIMING.

AT 18Z...LEFTOVERS FROM NIGHTTIME MCS WERE EXITING THE FAR EASTERN
SECTIONS OF THE CWA WITH SIGNIFICANT CLOUD COVER STILL OVER THE
EASTERN HALF OF THE CWA. WESTERN HALF WAS MOSTLY SUNNY. SFC
ANALYSIS SHOWED A 1015 MB LOW OVER EASTERN COLORADO WITH LOW
PRESSURE TROUGH EXTENDING NORTH INTO NORTH DAKOTA. 60+ DEW POINTS
WERE BEING WRAPPED WESTWARD ALONG THE NE/KS BORDER TOWARD THE APEX
OF THE TROUGH. INVERTED SFC RIDGE EXTENDED SOUTHWEST FROM WISCONSIN
INTO EASTERN KANSAS. 65 TO 68 DEW PTS WERE POOLED JUST WEST OF THIS
RIDGE IN THE AREA OF SOUTHEAST NEBRASKA/SOUTHWEST IOWA. A STALLED
FRONTAL BOUNDARY EXTENDED FROM THE TEXAS GULF COAST NORTHEAST INTO
CENTRAL GEORGIA WITH A WEAK SFC LOW IN CENTRAL ALABAMA.

OVER THE NEXT 48 HRS...NOT EXPECTING A DRASTIC CHANGE IN OUR WEATHER
PATTERN. WITH THE SFC FRONT ALONG THE GULF COAST...LOOKS AS IF
MOISTURE FROM THE GULF WILL REMAIN CUTOFF FROM OUR REGION. 500 MB
HIGH PRESSURE CONTINUES TO BE PROGGED TO SLOWLY BUT SURELY MOVE
WEST. THE 20/12Z 5H UPPER AIR PRESSURE FALLS INDICATE THIS SOLUTION
LOOKS PROMISING WITH HEIGHT RISES OVER ARIZONA AND HEIGHT FALLS OVER
THE TEXAS PANHANDLE. THIS DEVELOPMENT SHOULD GENERATE MORE OF A
NORTHWEST FLOW COMPONENT IN THE STEERING WINDS ACROSS WESTERN
KANSAS...AND THUS INCREASE THE CHANCES FOR MCS/S TO PROGRESS ACROSS
MORE OF MY CWA AFTER SHORTWAVES CREST THE TOP OF THE RIDGE. SFC HIGH
PRESSURE PROGGED TO EXPAND OVER MORE OF THE EASTERN U.S. WITH ITS
RIDGE NOSE STILL IN THE VICINITY OF EASTERN KANSAS. THIS WILL MEAN A
CONTINUATION OF THE SOUTHEAST TO EAST FLOW ACROSS THE AREA AND THUS
TRAP THE 60+ DEW PT AIR AS IT POOLS AGAINST THE HIGHER TERRAIN.

THE FIRST S/W OF WHICH TO BE CONCERNED IS SHOWING UP ON THE W/V LOOP
FROM NORTHERN COLORADO INTO SOUTHERN WYOMING. THIS FEATURE CURRENTLY
IS HELPING TO TOUCH OF MOUNTAIN CONVECTION. BELIEVE THIS S/W WILL
RESULT IN A NEAR REPEAT OF LAST NIGHT WITH AN MCS FORMING AND
PROGRESSING ACROSS PRIMARILY THE NORTHERN HALF OF MY CWA FOLLOWING
THE BEST MOISTURE AXIS. THE NEXT S/W TO INFLUENCE OUR WEATHER
CURRENTLY EXTENDS FROM EASTERN IDAHO INTO NORTHWEST WYOMING. THIS
FEATURE COULD EITHER RESULT IN AN EXTENSION OF LEFTOVER PCPN SATURDAY
MORNING OR HELP TO TRIGGER AFTERNOON CONVECTION SATURDAY. EITHER
WAY...I WILL KEEP CHANCES OF PCPN GOING FOR SATURDAY AS WELL. AND
WITHOUT ANY BIG CHANGES EXPECTED THROUGH SUNDAY...I WILL MENTION
EITHER A CHANCE OF PCPN BOTH SATURDAY NIGHT AND SUNDAY. WITH MORE OF
A NORTHWEST FLOW IN THE STEERING WINDS EXPECTED...DUE TO THE WESTWARD
MOVEMENT OF THE 5H HIGH AS MENTIONED ABOVE...WILL SLOWLY INCREASE
POPS AS THE PERIODS PROGRESS IN SOUTHWESTERN SECTIONS OF THE CWA.
ALSO DURING SUNDAY...THE STRONGEST S/W OF THE BUNCH IS FORECAST TO
MOVE OVER WESTERN KANSAS.

FOR TEMPERATURES...FWC/FAN/FMR SHOW LITTLE DIFFERENCE FROM EACH
OTHER AND WILL GO CLOSE TO THESE FIGURES EXCEPT FOR NORTHEAST
SECTIONS WHERE LEFT OVER MCS CLOUD DEBRIS SHOULD INHIBIT INSOLATION
HEATING THE LONGEST.

EXTENDED FORECAST...

ADVERTISEMENT OF FROPA CONTINUES BY ALL MODELS LATE SUNDAY/EARLY
MONDAY. TIMING OF FROPA REMAINS TO BE IN QUESTION HOWEVER SO WILL
NOT ATTEMPT TO NAIL DOWN POPS OR TEMPS. AFTER TUESDAY...5H HIGH
POSITION IS GENERALLY PROGGED TO SLIDE WEST AND WEAKEN AS LOW LEVEL
WINDS VEER TO A MOIST SOUTHERLY DIRECTION BY THURSDAY. WILL NOT MAKE
ANY MAJOR CHANGES TO GOING FORECAST WITH SLIGHT POPS HARD TO RULE
OUT EACH DAY. MRF BRINGS VIGOROUS WAVE ACROSS NORTHERN TIER ON
FRIDAY WITH LEE TROF SETTING UP SO WILL MENTION SLIGHT POPS THEN AS
WELL.

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

DDC 065/090 068/089 068 324
GCK 063/090 066/089 066 243
EHA 062/093 065/093 065 223
LBL 062/092 065/091 065 223
HYS 066/083 069/083 069 535
P28 063/090 066/089 066 243

.DDC...NONE.

SLEIGHTER/POAGE