Severe Thunderstorm Warning 41, NWS Rapid City, SD

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
145 PM MDT SAT JUN 3 2000

MODELS ARE SIMILAR THROUGH MONDAY. AFTER TOMORROW...THINGS JUST GET
WARMER AND DRIER. CURRENTLY THE SURFACE LOW IS SITTING OVER THE PINE
RIDGE AREA. WARM FRONT IS STRETCHED OUT ACROSS SOUTHERN NEBRASKA
WITH A TROF EXTENDING NORTHWESTWARD INTO MT BETWEEN KMLS/KBHK.
A COLD FRONT ALSO STRETCHES TO THE WEST THROUGH WYOMING. SATELLITE
IS SHOWING CU STARTING TO POP...AND WE HAVE SEEN SEVERAL TCU SOUTH
OF THE OFFICE...BUT THEY KEEP GETTING BLOWN OVER AND SHEARED OUT.
GOES SOUNDER PRODUCTS ARE SHOWING THAT THINGS ARE VERY UNSTABLE OVER
WESTERN SD...BUT THERE IS STILL A GOOD CAP OVER THE AREA. SPECIAL
SOUNDING THIS AFTERNOON IDICATED 700 J/KG OF CAPE WITH -435 J/KG OF
CIN. THEREFORE...WE'RE STILL WAITING FOR MORE HEATING BEFORE THINGS
TO START FIRING UP IN THIS AREA. BUT...WITH STORMS ALREADY GOING IN
MONTANA IT SHOULD BE A BUSY EVENING FOR OUR CWA ONCE WE LOSE THE CAP.

ON MONDAY NIGHT...A SURFACE LOW INTENSIFIES OFF THE LEE OF THE MT
ROCKIES AND SETS UP A WARM FRONT/TROF OVER THE WY/SD BORDER.  WITH A
SHORTWAVE APPROACHING FROM THE WEST AND SOME UPPER LEVEL
DIVERGENCE...THERE COULD BE A FEW THUNDERSTORMS IN THE MISSING
PERIOD. WILL THEREFORE ADD MONDAY NIGHT TO THE NORTHERN HALF OF THE
ZONES.

IN THE EXTENDED...SUMMER IS COMING. 700 TEMPS ON THE MRF ARE 10 TO
15 DEGREES MONDAY AFTERNOON...12 TO 15 DEGREES TUESDAY AND WEDNESDAY
AFTERNOON. 850 TEMPS GO INTO THE UPPER 20S AND LOWER TO MID 30S BY
TUESDAY AND WEDNESDAY.  THE NOGAPS HAS A SIMILAR PATTERN...BUT NOT
QUITE AS WARM AS THE MRF. THEREFORE I WILL GO WITH WARMER TEMPS BUT
NOT QUITE JUMP AT WHAT THE MRF GUIDANCE NUMBERS ARE SHOWING. WHILE
THERE WILL BE SEVERAL SURFACE FEATURES (FRONTS/TROFS) MOVING THROUGH
THE REGION...1000-500 MB RH IS LESS THAN 40 PERCENT EACH DAY AND
WITH UPPER AIR TEMPERATURES BEING SO WARM...WE SHOULD REMAIN CAPPED.

.UNR...NONE.

FRANSEN