Severe Thunderstorm Warning 67, NWS Cheyenne, WY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
211 PM MDT THU JUL 20 2000

MOR WDSPRD AND INTS CNVTN HAS DVLPD JUST TO THE S OF THE CWA ERY THIS
AFTN AND SHUD MAINLY STAY OVR ERN CO THRU THE EVE.  STILL THE BEST
THREAT FOR TSTMS IN OUR CWA THIS EVE WILL BE ON THE NRN FRINGE OF THE
CO ACTVTY.  NEAR THE CO BORDER...CAPE VALUES WILL REMAIN HI AND CIN HAS
ALMOST BEEN OVERCOME...SO SOME STG TSTMS ARE PSBL.  TSTMS WILL BE LESS
WDSPRD THAN IN CO DUE TO THE LCTN OF THE H250 JET AND LACK AND A
LACK OF DYNAMICS ALFT.  WITH THE THETA E RDG AXIS OVR THE CWA TNGT
XPCT SOME OF THE SHWRS AND TSTMS NOW TO OUR W AND NW TO LINGER THRU
MUCH OF THE NGT.  MDLS CLOSE FOR THE CWA THRU SAT AND PREFER THE BTR
DEPICTION OF THE SHRTWV TROF ROUNDING THE RDG AND MOVG OVR THE CWA
ON THE AVN.  PWS DCRS SOME ON FRI AND AGN ON SAT FOR AN ASOCTD DCRS
IN POPS EACH DAY.  THE BTR LLM WILL REMAIN IN XTRM SE WY AND THE SRN
NEB PNHNDL DRG THAT TIME...FOR THE BEST CHCS OF TSTMS FRI AND SAT IN
THE CWA.  RDG ALFT BLDS TO OUR W THRU SAT...INCRSNG TEMPS ALFT AND
SLWLY STBLZG THE AMS.  THE SHRTWV TROF MENTIONED ABV WILL AID IN
TSTM DVLPMNT OVR THE CWA FRI AFTN AND EVE.  TEMPS WILL WARM BY SAT
TO AT OR ABV NORMAL READINGS AND MOS GUIDANCE LOOKS CLOSE.

.EXTENDED DISCUSSION...
5H RIDGE AMPLIFIES OVR THE CENT ROCKYS DURG WEEKEND WHICH WILL
DIVERT ANY WK DISTS WELL N OF AREA AND PRETTY WELL CAP OFF ANY
CONVECTION FOR SUN AND MON.  NRN STREAM ENERGY THEN DIVES SE OUT
OF WRN CANADA AND SUPPRESSES RIDGE INTO THE SRN U.S.  THIS WILL
ALLOW FOR MORE WK SHTWV ENERGY TO PASS OVER WY WITH A SLIGHTLY
BETTER CHANCE FOR RAIN AS WELL AS A BIT COOLER TEMPS.

.CYS...
WY...NONE.
NE...NONE.

WEILAND/EMANUEL

NEZ001>003-019>021-054-055-WYZ059>070-211900-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
1046 AM MDT THU JUL 20 2000

SPOTTER ACTIVATION WILL LIKELY BE NEEDED LATE THIS AFTERNOON AND THIS
EVENING IN AREAS EAST OF THE LARAMIE RANGE.

DISCUSSION...THE WEATHER PATTERN FOR THIS AFTERNOON AND EVENING OVER
SOUTHEAST WYOMING AND THE WESTERN NEBRASKA PANHANDLE WILL BE SIMILAR
TO THAT OF THURSDAY.  A MOIST SURFACE UPSLOPE WIND FLOW WILL BE IN
PLACE OVER THE AREA...WITH A WEAK UPPER LEVEL DISTURBANCE MOVING
OVER THE ROCKIES THIS AFTERNOON.  THE RESULT WILL BE A STILL MOIST
AND UNSTABLE AIR MASS WITH A GOOD POSSIBILITY OF A SCATTERED COVERAGE
OF SEVERE THUNDERSTORMS DEVELOPING.  THE STORMS WILL FORM IN THE
EARLY AFTERNOON NEAR THE LARAMIE RANGE...EARLIER THAN ON THURSDAY...
AND MOVE TO THE SOUTHEAST AT 30 MPH.  THE MAIN THREAT FROM THE
STORMS WILL BE HAIL OF BETWEEN 1 AND 2 INCHES IN DIAMETER...WIND
GUSTS TO 60 MPH...BRIEF HEAVY RAIN AND DANGEROUS LIGHTNING.

WEILAND
WCJIN-WYSE-WYNE

NEZ001>003-019>021-054-055-WYZ059>070-201900-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
1102 AM MDT THU JUL 20 2000

SPOTTER ACTIVATION MAY BE NEEDED LATE THIS AFTERNOON AND THIS
EVENING OVER EXTREME SOUTHEAST WYOMING AND THE SOUTHERN NEBRASKA
PANHANDLE.

DISCUSSION...A MOIST AND UNSTABLE AIR MASS WILL BE IN PLACE IN EXTREME
SOUTHEAST WYOMING AND THE SOUTHERN NEBRASKA PANHANDLE.  THAT AREA IS
FROM CHEYENNE AND WHEATLAND EASTWARD TO BRIDGEPORT AND SIDNEY.  A
STATIONARY FRONT WILL BE ALONG THE LARAMIE RANGE THIS AFTERNOON AND
EVENING AND WILL PROVIDE THE FOCUS FOR THUNDERSTORM DEVELOPMENT
AFTER 3 PM.  STORMS WILL THEN MOVE TO THE EAST OR SOUTHEAST INTO THE
SOUTHERN NEBRASKA PANHANDLE.  IN ADDITION TO THE MOIST AND UNSTABLE
AIR OVER THAT AREA THIS AFTERNOON AND EVENING...STRONG WINDS IN THE
UPPER ATMOSPHERE WILL AID IN INTENSIFYING ANY THUNDERSTORMS THAT
FORM.  THE PRIMARY THREAT FROM THEq STORMS WILL BE LARGE HAIL AND WIND
GUSTS TO 60 MPH.  BRIEF HEAVY RAIN WILL ALSO ACCOMPANY THE STORMS.

WEILAND
WCJIN-WYSE-WYNE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE, WY
258 PM MDT THU JUL 20 2000

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....
#
0445 PM    5 NW KIMBALL              NE   .75 INCH HAIL
07/12/00   KIMBALL

0800 PM    10 N LODGEPOLE            NE   .75 INCH HAIL
07/15/00   CHEYENNE

GRIFFITH