Severe Thunderstorm Warning 81, NWS Cheyenne, WY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1247 PM MDT TUE JUL 1 2003

SHORT TERM...SOUTHWEST FLOW ALOFT TONIGHT WILL VEER SOMEWHAT TO WEST
SOUTHWEST WED AS A STRONG SHORTWAVE MOVING ACROSS SOUTHERN CANADA
FLATTENS OUT THE TOP PORTION OF THE BROAD RIDGE CURRENTLY SPRAWLED
OVER THE CENTRAL AND WESTERN PORTION OF THE U.S. A WEAKER SHORTWAVE
WILL PUSH ACROSS THE CYS FORECAST AREA THIS EVENING...AND BASED ON A
SIMILAR SCENARIO YESTERDAY THAT PRODUCED A FEW STORMS...CANNOT RULE
OUT A FEW EVENING THUNDERSTORMS THIS EVENING FROM THE LARAMIE RANGE
EASTWARD. TEMPERATURES TONIGHT WILL COOL ONLY INTO THE 50S TO LOWER
60S IN LOWER ELEVATIONS...WITH UPPER 40S POSSIBLE IN THE NORMALLY
COLDER LARAMIE VALLEY. WEST WINDS WILL OCCUR WED BEHIND TONIGHT/S
SHORTWAVE...WITH ADIABATIC WARMING AND DRYING PRODUCING TEMPS
RANGING FROM THE MID 80S TO MID 90S WED OUTSIDE THE MOUNTAINS. WED
SHOULD REMAIN DRY WITH VERY LOW DEWPOINTS AND LACK OF LIFTING
DYNAMICS.

LONG TERM...VERY WARM AND GENERALLY DRY WEATHER WILL BE OVER THE CWA
FOR THE WED NIGHT THROUGH NEXT TUE TIME PERIOD. A RIDGE OF HIGH
PRESSURE ALOFT OVER THE ROCKIES WILL BE FLATTENED SLIGHTLY THU
THROUGH SUNDAY AS SEVERAL SIGNIFICANT SHORTWAVE TROUGHS MOVE FROM
WEST TO EAST FROM NORTHERN ALBERTA TO NORTHERN MANITOBA. MOST OF THE
ENERGY MOVES TO THE NORTH OF THE CWA DURING THAT TIME. AT LEAST
EARLY IN THIS PERIOD THE VERY DRY AIR UPSTREAM OF THE CWA WILL MOVE
OVER THE CENTRAL ROCKIES. HOWEVER...THE SHORTWAVE TROUGHS HELP PUSH
COLD FRONTS AND A PERIOD OF COLD AIR ADVECTION THROUGH THE CWA THU
NIGHT AND AGAIN SUN NIGHT. THE BOUNDARIES THEN LIFT EASTWARD THE
FOLLOWING DAY WITH TEMPERATURES RETURING TO THE CURRENT VERY WARM
LEVELS BY SATURDAY AND TUE. THE COLD FRONTS WILL ALSO PROVIDE SOME
SURFACE FORCING FOR AREAS TO THE EAST OF THE LARAMIE RANGE. THE
BOUNDARY WILL KEEP LATE DAY LOW POPS GOING FOR FRI AFTERNOON AND
EVENING THROUGH TUE AFTERNOON AND EVENING IN THE GRIDS BUT MAY LEAVE
OUT OF THE WORDED FORECAST. THE LATEST GFS NOW DEVELOPS SOUTHWEST
FLOW ALOFT OVER THE CWA WITH EVEN LESS ENERGY INTO THE CENTRAL
ROCKIES THAN ITS PREVIOUS RUNS. THE SYNOPTIC PATTERN ON THE GFS IS
SIMILAR TO THAT OF THE UKMET AND ECMWF FOR THE WEEKEND AND EARLY
NEXT WEEK. THE GFS ALSO CONTINUES TO BE MORE MOIST THAN THE ETA WITH
PRECIPITABLE WATER VALUES IN THE EAST PART OF THE CWA ABOUT A
QUARTER OF AN INCH HIGHER. THE GFS HAS MORE LIGHT QPF OVER THE EAST
PART OF THE CWA FOR THU THROUGH THE WEEKEND. LOOKING AT THE 12Z
PRECIPITABLE WATER VALUES...BELIEVE SOMEWHERE IN BETWEEN WILL BE
CLOSE. OTHER THAN THE DAYS AFTER THE FRONTAL PASSAGE...700 MB
TEMPERATURES CLIMB TO ABOVE 14C AND SO SURFACE READINGS WILL LIKELY
GO ABOVE GUIDANCE NUMBERS.

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

WEILAND

NEZ001>003-019>021-054-055-WYZ059>070-021130-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
1032 AM MDT TUE JUL 1 2003

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

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

ISOLATED LATE DAY STORMS WILL BE POSSIBLE TODAY...BUT THEY ARE
EXPECTED TO BE RATHER WEAK.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

GENERALLY DRY WEATHER AND SUMMERLIKE TEMPERATURES WILL PREVAIL
THROUGH THE HOLIDAY WEEKEND.  A FEW LATE DAY THUNDERSTORMS CANNOT BE
RULED OUT HOWEVER...ESPECIALLY FRIDAY AND SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.