Hail and Damaging Wind in South Dakota, August 3, 2003

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
230 PM MDT SUN AUG 3 2003

MAIN FCST CONCERN IS THE NEXT 24-36 HRS AS SERIES OF DISTURBANCES
BREAK DOWN STRONG UPR LVL RDG. ALREADY PLENTY OF CONVECTION GOING
ACROSS SWRN MT INTO NRN UT AS WELL AS SRN WY INTO CO. THIS ACTIVITY
WILL GRADUALLY MOVE INTO CWA THROUGH THE EVENING AND OVERNIGHT
HOURS. MDLS SHOWING BEST LIFT AND UPR LVL DIVERGENCE GOING FROM NE
WY INTO NWRN SD TNGT SO WENT WITH 50 POPS THERE AND GRADUALLY
LOWERED THEM AS YOU GO E. LKS LIKE SOME STORMS OVR NE WY MAY START
OUT PRODUCING DRY LIGHTNING THROUGH THE AFTN AND INTO THE EARLY
EVENING...SO WILL ISSUE A RED FLAG WARNING FOR NE WY FIRE WX ZNS.

TMRW SFC TROF/FNT WILL MOVE THROUGH CWA...THIS COMBINED WITH UPR LVL
DISTURBANCES WILL HELP TO KEEP STORMS GOING THROUGH THE DAY. LKS
LIKE BEST CHC WILL BE ERN ZNS WHERE BEST INSTABILITY WILL BE AND THE
BEST LIFT REACHES THERE IN THE EARLY TO MID AFTN. TEMPS TRICKY
BECAUSE OF THE EXPECTED CLD CVR AND CHC FOR RAINFALL THROUGH MUCH OF
THE DAY. DID NOT STRAY TOO FAR FROM GUIDANCE AND WENT WITH HIGHS
GENERALLY IN THE 80S WITH THE WARMEST TEMPS ACROSS SW SD WHERE IT
LKS LIKE MORE SUN WILL OCCUR IN THE AFTN. DECENT INSTABILITY REMAINS
ACROSS ERN HALF OF CWA AROUND 00Z...BUT NOT MUCH LIFT...SO KEPT IN
20 POPS FROM NW SD INTO S CTRL FOR THE EVENING HOURS.

RDG STARTS TO REBUILD THROUGH THE REMAINDER OF THE FCST PD AND
REALLY STRENGTHENS FOR THE SECOND HALF OF THE WEEK AS CUTOFF LOW
STARTS TO MOVE INTO NWRN U.S. SHOULD SEE AT LEAST A COUPLE OF DAYS
WITH HIGHS AOA 100 OVER THE SD PLNS STARTING THU. DRY CONDS WILL
RETURN WITH LTL MOISTURE TO WORK WITH UNDER THE RDG.

.UNR...RED FLAG WARNING THIS AFTERNOON AND TONIGHT FOR DRY
       LIGHTNING ACROSS WYOMING FIRE ZONES 297N...297S...298...299.
       FIRE WX WATCH FOR DRY LIGHTNING THIS EVENING ACROSS SOUTH
       DAKOTA FIRE ZONES 260 AND 262.

JMG

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-041300-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
704 AM MDT SUN AUG 3 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND
NORTHEASTERN WYOMING.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTHEAST WYOMING
AND FAR WESTERN SOUTH DAKOTA THIS AFTERNOON AND EVENING. THE MAIN
THREAT FROM THE SEVERE THUNDERSTORMS WILL BE WIND GUSTS GREATER THAN
60 MPH AND HAIL LARGER THAN 3/4 INCH.

AN UPPER LEVEL DISTURBANCE WILL MOVE INTO NORTHEAST WYOMING LATE
THIS AFTERNOON AND INTO WESTERN SOUTH DAKOTA TONIGHT. THUNDERSTORMS
ARE EXPECTED TO DEVELOP OVER THE BIG HORN MOUNTAINS AND MOVE INTO
NORTHEAST WYOMING LATE THIS AFTERNOON. THE MAIN THREAT WITH THESE
STORMS WILL BE DAMAGING WIND GUSTS. LOW HUMIDITIES WILL RESULT IN THE
POSSIBILITY FOR DRY LIGHTNING WITH SOME STORMS THROUGH THE
EVENING HOURS...ESPECIALLY ACROSS NORTHEAST WYOMING. THESE STORMS
WILL MOVE INTO WESTERN SOUTH DAKOTA DURING THE EVENING HOURS. THE
THREAT FOR SEVERE STORMS SHOULD BEGIN TO DIMINISH BY LATE EVENING.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

THE CHANCE FOR THUNDERSTORMS WILL CONTINUE ON MONDAY AS A SURFACE
BOUNDARY CROSSES THE AREA. THERE IS A SLIGHT RISK FOR SEVERE
THUNDERSTORMS ACROSS ALL OF WESTERN SOUTH DAKOTA WITH THE MAIN
THREATS BEING LARGE HAIL AND WIND GUSTS GREATER THAN 60 MPH. THE
REST OF THE WEEK LOOKS DRY AND HOT AS AN UPPER LEVEL RIDGE BUILDS
NORTHWARD.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY.