Tornado Warning 10, NWS Rapid City, SD

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
315 PM MDT TUE JUN 10 2003

TYPICAL JUNE WX PATTERN WILL CONTINUE FOR THE NEXT SEVERAL DAYS AS
SERIES OF UPPER LEVEL DISTURBANCES CROSS THE NORTHERN PLAINS THRU
FRI. NOT MUCH IN THE WAY OF DIFFERENCES BETWEEN THE DIFFERENT 12Z
MODEL RUNS. TIMING OF THESE WAVES WILL CONTINUE TO BE SOMEWHAT
DIFFICULT...ESPECIALLY BEYOND THURSDAY...BUT WILL GENERALLY FOLLOW
CLOSE TO GFS THRU THE END OF THE WEEK.

RIGHT NOW...STORMS ARE FIRING IN EASTERN WY AHEAD OF SHRTWV MOVING
ACROSS SOUTHERN MT. STRONG SHEAR AND CAPES OF AROUND 1000 J/KG WILL
BE CONDUCIVE TO THE FORMATION OF SUPERCELLS ACROSS NORTHEASTERN WY
LATE THIS AFT AND INTO THIS EVE. MAIN THREATS LOOK TO BE FOR LARGE
HAIL AND DAMAGING WINDS. THESE STORMS WILL SLOWLY TRACK EASTWARD
THRU THE EVENING. ATMOS IN WESTERN SD MORE STABLE RIGHT NOW...BUT
THAT WILL CHANGE OVERNIGHT AS WAVE APPROACHES AND THETA-E ADV
INCREASES. STORMS SHOULD WEAKEN SOME AS THEY MOVE INTO WESTERN SD
AND DAYTIME HEATING SUBSIDES...BUT COULD STILL BE STRONG INTO THIS
EVENING.

ON WED...SETUP LOOKING VERY SIMILAR TO YESTERDAY AS STRONGER
SHRTWV...OVER NORTHWEST MT NOW...WILL MOVE INTO THE NORTHERN PLAINS.
WEAK COLD FRONT WILL MOVE ACROSS THE CWA LATE IN THE MORN AND AFT.
IN WARM SECTOR ACROSS SOUTHERN SD...SB CAPES ARE PROGGED TO INCREASE
TO NEAR 2000 J/KG WITH DECENT DIRECTIONAL AND SPEED SHEAR DURING THE
AFT. SURF LOW NOW DEVELOPING ALONG THE FRONTAL BOUNDARY IN WY IS
PROGGED TO MOVE SLOWLY ACROSS NORTHERN NEB. SLIGHT RISK OVER MUCH OF
WESTERN SD LOOKS WARRANTED WITH BETTER CHANCES EXPECTED OVER
SOUTHERN SD FROM MID TO LATE AFT AS THE FRONT APPROACHES DURING MAX
HEATING AND INSTABILITY. SYSTEM WILL EXIT EASTERN CWA EARLY IN THE
EVENING.

IN THE EXTENDED...AS UPPER TROF OVER WESTERN CONUS DEEPENS LATE THIS
WEEK AND WEAK RIDGING BUILDS ACROSS THE UPPER MIDWEST...SOUTHWEST
FLOW WILL DEVELOP ACROSS WESTERN PARTS OF THE REGION. MAIN CHANCES
FOR STORMS WILL BE ACROSS NORTHEAST WY AND FAR WESTERN SD THIS
WEEKEND AND INTO EARLY NEXT WEEK...WITH MAINLY DRY AND WARM
CONDITIONS EXPECTED ACROSS EASTERN CWA.

.UNR...NONE.

ST

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-111400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
600 AM MDT TUE JUN 10 2003

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

.DAY ONE...TODAY AND TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE
THIS AFTERNOON ACROSS NORTHEASTERN WYOMING AND THE BLACK HILLS...
THEN SPREAD EASTWARD DURING THE EVENING AND OVERNIGHT HOURS. SOME OF
THESE STORMS MAY BECOME SEVERE LATE THIS AFTERNOON AND EARLY
EVENING ACROSS NORTHEASTERN WYOMING AND THE BLACK HILLS...WITH THE
PRIMARY THREAT BEING HAIL LARGER THAN 3/4 INCH AND WIND GUSTS GREATER
THAN 60 MPH. ANY STORMS THAT DEVELOP WILL THEN MOVE EASTWARD ACROSS
WESTERN AND CENTRAL SOUTH DAKOTA DURING THE EVENING AND OVERNIGHT
HOURS. EVEN THOUGH THE SEVERE WEATHER THREAT WILL NOT BE AS GREAT
OVER THESE AREAS...A FEW STORMS MAY PRODUCE HAIL LARGER THAN 3/4 OF
AN INCH.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A STRONGER UPPER LEVEL DISTURBANCE WILL MOVE INTO THE NORTHERN
PLAINS ON WEDNESDAY. THIS DISTURBANCE MAY TRIGGER SOME SEVERE
THUNDERSTORMS...PRIMARILY OVER WESTERN AND CENTRAL SOUTH DAKOTA. AN
ISOLATED TORNADO OR TWO WILL BE POSSIBLE ACROSS CENTRAL SOUTH
DAKOTA.

A DAILY CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS WILL THEN BE
POSSIBLE THROUGH THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ASSISTANCE MAY BE NEEDED LATE THIS AFTERNOON AND EVENING...
ESPECIALLY OVER NORTHEASTERN WYOMING AND FAR WESTERN SOUTH
DAKOTA.

JOHNSON