Severe Thunderstorm Warning 52, NWS Cheyenne, WY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
156 PM MDT SUN JULY 4 2004

.SHORT TERM...THUNDERSTORMS WILL BE FAIRLY WIDESPREAD THROUGH THE
EVENING OVER MUCH OF THE CWA AHEAD OF A SHORTWAVE TROUGH CURRENTLY
IN CENTRAL WYOMING.  VERTICAL PROFILES EARLY THIS AFTERNOON WOULD
INDICATE THAT MOST OF THE ACTIVITY IN THE WESTERN TWO THIRDS OF THE
CWA WILL PRODUCE WIND GUSTS TO ABOUT 50 MPH.  MEANWHILE IN PARTS OF
THE PANHANDLE BETTER SHEAR...LOW LEVEL MOISTURE AND BUOYANCY WOULD
INDICATE THE POSSIBILITY OF HAIL ALONG WITH THE WINDS.  MOST OF THE
STORMS WILL ALSO PRODUCE CONSIDERABLE LIGHTNING.  AFTER THE STORMS
DIMINISH AND MOVE EAST THE NEXT CONSIDERATION WILL BE ANY WEATHER
BEHIND A COLD FRONT WHICH WILL MOVE THROUGH THE CWA...EAST OF THE
LARAMIE RANGE...THROUGH 08Z.  MODELS INCREASE THE BOUNDARY LAYER
MOISTURE AND THE WEAK SYNOPTIC LIFT WILL BE PRESENT IN THE CYCLONIC
FLOW ALOFT.  SO WILL CONTINUE THE IDEA OF LOWER CEILINGS AND
SCATTERED POPS BEHIND THE FRONT TONIGHT IN THE NORTH PART OF THE
CWA. MONDAY SHOULD BE ANOTHER ACTIVE DAY WITH THE CWA UNDER THE COOL
CYCLONIC FLOW ALOFT.  THE GFS IS MORE MOIST AND HAS THE TROUGH
DEEPER THAN THE ETA.  WILL GO WITH ANYWHERE FROM 40 TO 60 PERCENT
POPS BY THE AFTERNOON.  SPC HAS RISK OF SEVERE IN THE SOUTHEAST PART
OF THE CWA AND MAY BE OK BEHIND THE FRONT.  HOWEVER...COOLER SURFACE
TEMPERATURES MAY LIMIT BUOYANCY SOME.  700 MB TEMPERATURES COOL TO
BETWEEN 4C AND 8C FOR MONDAY...WITH HIGHS 6 TO 12 DEGREES COOLER
THAN TODAY.

.LONG TERM...RAIN WILL REMAIN POSSIBLE MON NIGHT AS A SHORTWAVE
MOVES FROM NORTHEASTERN WY OVER THE DAKOTAS AND EXERTS ITS INFLUENCE
ON THE CYS FORECAST AREA. NORTHWESTERLY FLOW ALOFT TUE WILL BACK TO
MORE WESTERLY WED AS AN UPPER LEVEL CUTOFF LOW PRESSURE SYSTEM MOVES
SOUTHEASTWARD OVER WESTERN CANADA. MODELS DIFFER ON THE HANDLING OF
THE CUTOFF WITH THE GFS MUCH FASTER THAN THE ETA. FLOW ALOFT WILL
BACK TO SOUTHWESTERLY THU AND SHOULD REMAIN SOUTHWESTERLY FRI AS THE
CUTOFF LOW SHEARS AND WEAKENS AS IT MOVES EAST NORTHEAST OVER
SOUTHERN CANADA. SOUTHWEST FLOW PATTERN SATURDAY WILL BECOME
SOMEWHAT RIDGIER SUNDAY AS AN UPPER LEVEL RIDGE BEGINS TO BUILD OVER
THE ROCKIES. AT THE SURFACE...HIGH PRESSURE OVER THE NORTHERN PLAINS
AND NORTHERN ROCKIES MON NIGHT WILL PRODUCE UPSLOPE FLOW EAST OF THE
MOUNTAINS THUS WILL GO WITH SCATTERED POPS MON EVENING. RAINFALL
WILL END FROM NORTHWEST TO SOUTHEAST LATE MON NIGHT. TUE WILL BE DRY
WITH TEMPERATURES REMAINING BELOW NORMAL. WEAK LEESIDE SURFACE
TROUGHING WILL OCCUR WED WITH DOWNSLOPE FLOW AND SUBSEQUENT
ADIABATIC WARMING BOOSTING TEMPS AND KEEPING THINGS DRY. THU WILL
REMAIN WARM BUT A CHANCE OF LATE DAY THUNDERSTORMS WILL RETURN AS
MID LEVEL MOISTURE INCREASES. LEESIDE CYCLOGENESIS WILL INDUCE LOW
LEVEL UPSLOPE FLOW FRI WHICH WILL SUPPRESS TEMPS SOMEWHAT WITH A
CHANCE OF RAIN. SURFACE HIGH PRESSURE SETTLING OVER THE NORTHERN
HIGH PLAINS SAT WILL CONTINUE LOW LEVEL UPSLOPE WITH A CORRESPONDING
CHANCE OF RAIN. CANNOT RULE OUT LATE DAY STORMS SUN AS MOISTURE AND
UPSLOPE LINGER.

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
1018 AM MDT SUN JUL 4 2004

NEZ001>003-019>021-054-055-051102-
BANNER-BOX BUTTE-CHEYENNE-DAWES-KIMBALL-MORRILL-SCOTTS BLUFF-SIOUX-
INCLUDING THE CITIES OF...ALLIANCE...CHADRON...KIMBALL...
SCOTTSBLUFF AND SIDNEY
1018 AM MDT SUN JUL 4 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEASTERN WYOMING AND THE
WESTERN NEBRASKA PANHANDLE.

.DAY ONE...TODAY AND TONIGHT

A SCATTERED COVERAGE OF THUNDERSTORMS WILL DEVELOP OVER THE
WESTERN NEBRASKA PANHANDLE BY MID AFTERNOON AND THEN MOVE EAST
THROUGH THE EVENING.  THE ACTIVITY WILL BE SIMILAR TO THAT
OF SATURDAY...WITH MOST STORMS PRODUCING CONSIDERABLE LIGHTNING...
A PERIOD OF MODERATE RAINFALL...BRIEF AND LOCAL WIND GUSTS TO 50
MPH AND GENERALLY SMALL HAIL.

THE BETTER INSTABILITY...MOISTURE AND WIND SHEAR WILL BE OVER
THE FAR EAST PARTS OF THE AREA.  IN THAT AREA...SOME OF THE
STORMS MAY PRODUCE HAIL UP TO THREE QUARTERS OF AN INCH IN
DIAMETER.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

SCATTERED THUNDERSTORMS WILL OCCUR ACROSS THE PANHANDLE MONDAY
AFTERNOON AND EVENING...WITH SOME SEVERE STORMS POSSIBLE.
SCATTERED THUNDERSTORMS CAN ALSO BE EXPECTED ON FRIDAY AND
SATURDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING...AND
AGAIN MONDAY AFTERNOON...ESPECIALLY FROM DAWES TO CHEYENNE
COUNTIES.

WYZ059>070-051102-
CHEYENNE FOOTHILLS-CONVERSE-GOSHEN-LARAMIE RANGE-LARAMIE VALLEY-
NIOBRARA-NORTH CARBON-NORTH LARAMIE RANGE-PINE BLUFFS-PLATTE-
SNOWY RANGE-SOUTHWEST CARBON-
INCLUDING THE CITIES OF...CHEYENNE...DOUGLAS...LARAMIE...LUSK...
RAWLINS...TORRINGTON AND WHEATLAND
1018 AM MDT SUN JUL 4 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEASTERN WYOMING AND THE
WESTERN NEBRASKA PANHANDLE.

.DAY ONE...TODAY AND TONIGHT

A SCATTERED COVERAGE OF THUNDERSTORMS WILL OCCUR ACROSS MUCH
OF SOUTHEAST WYOMING THIS AFTERNOON AND EARLY EVENING.  THE
MAIN THREAT FROM THE STORMS WILL BE FREQUENT LIGHTNING AND
BRIEF AND LOCAL WIND GUSTS TO 50 MPH.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

SCATTERED THUNDERSTORMS WILL OCCUR ACROSS THE AREA MONDAY
AFTERNOON AND EVENING.  SCATTERED THUNDERSTORMS CAN ALSO
BE EXPECTED ON FRIDAY AND SATURDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

WEILAND