Severe Thunderstorm Warning 29, NWS Cheyenne, WY

057 
WWUS55 KCYS 282057
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
257 PM MDT TUE MAY 28 2013

NEC165-282130-
/O.CON.KCYS.SV.W.0029.000000T0000Z-130528T2130Z/
SIOUX NE-
257 PM MDT TUE MAY 28 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL
SIOUX COUNTY UNTIL 330 PM MDT...

AT 255 PM MDT...A SEVERE THUNDERSTORM WAS LOCATED 11 MILES NORTH OF
MORRILL...AND MOVING NORTH AT 25 MPH.

HAZARD...QUARTER SIZE HAIL AND 60 MPH WIND GUSTS.

SOURCE...RADAR INDICATED.

IMPACT...HAIL DAMAGE TO VEHICLES AND CROPS IS EXPECTED. EXPECT WIND
         DAMAGE TO ROOFS...SIDING AND TREES.

THE SEVERE THUNDERSTORM WILL AFFECT MAINLY RURAL AREAS OF SOUTH
CENTRAL SIOUX COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPORT SEVERE WEATHER CONTACT YOUR NEAREST LAW ENFORCEMENT AGENCY.
THEY WILL SEND YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN
CHEYENNE.

&&

LAT...LON 4208 10399 4233 10397 4223 10365 4202 10387
TIME...MOT...LOC 2057Z 200DEG 20KT 4212 10387

HAIL...1.00IN
WIND...60MPH

$$

RUBIN

369 
WWUS55 KCYS 282108
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
308 PM MDT TUE MAY 28 2013

NEC165-282118-
/O.CAN.KCYS.SV.W.0029.000000T0000Z-130528T2130Z/
SIOUX NE-
308 PM MDT TUE MAY 28 2013

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL SIOUX COUNTY IS
CANCELLED...

THE SEVERE THUNDERSTORM WARNING THAT PROMPTED THE WARNING HAS BEEN
UPGRADED TO A TORNADO WARNING.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM MDT.

LAT...LON 4208 10399 4233 10397 4223 10365 4202 10387
TIME...MOT...LOC 2108Z 200DEG 20KT 4218 10384

$$

RUBIN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1121 AM MDT TUE MAY 28 2013

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 227 AM MDT TUE MAY 28 2013

GOES WATER VAPOR IMAGERY/RUC UPPER AIR ANALYSIS A MORE PROGRESSIVE
PATTERN. THE TROUGH THAT HAD BEEN STATIONARY ALONG THE WEST COAST
WAS NUDGED EAST INTO THE GREAT BASIN IN RESPONSE TO AN APPROACHING
EASTERN PACIFIC RIDGE. THE RIDGE OVER THE GREAT PLAINS WAS SITUATED
OVER THE MISSISSIPPI VALLEY. LATE DAY CONVECTION DEVELOPED YESTERDAY
AS A SHORTWAVE INTERACTED WITH THE HIGH PLAINS DRYLINE. SIMILAR TO
THE PAST FEW DAYS...CONVECTION EVOLVED INTO AN MCS OVER THE CENTRAL
PLAINS AND MOVED EAST THROUGH THE MISSOURI VALLEY. THE REGIONAL
SURFACE ANALYSIS DEPICTED A WAVY STATIONARY FRONT FROM IOWA THROUGH
KANSAS THEN NORTH ALONG THE FRONT RANGE INTO SOUTHERN WYOMING.
SOMEWHAT DRIER AIR INFILTRATED THE WESTERN PANHANDLE WITH THE PASSAGE
OF THE SHORTWAVE. DEW POINTS THERE WERE 10 DEGREES COOLER COMPARED
TO 24 HOURS AGO. AMBIENT TEMPERATURES WERE ALSO ABOUT 10 DEGREES
COOLER WITH 40S PREVALENT.

THERE IS A GOOD CONSENSUS WITH THE 00Z SHORT RANGE MODELS AMPLIFYING
THE LONG WAVE UPPER LEVEL PATTERN DURING THE NEXT 24 TO 36 HOURS. THE
GREAT BASIN TROUGH DEEPENS AS IT TRANSITS THE CONTINENTAL DIVIDE
TONIGHT AND WEDNESDAY. SHORTWAVE ENERGY WILL LIFT NORTHEAST ACROSS
THE REGION AS THE TROUGH AXIS NEARS THE FRONT RANGE WEDNESDAY. A
CLOSED LOW DEVELOPS OVER WESTERN WYOMING EARLY WEDNESDAY AND BROADENS
WEDNESDAY NIGHT OVER NORTHERN WYOMING AND SOUTHEAST MONTANA. THE
FLOW ALOFT VEERS FROM SOUTHWESTERLY TO WESTERLY BY THE END OF THE
SHORT TERM.

SURFACE LOW OVER EASTERN COLORADO WILL DEEPEN TODAY IN RESPONSE TO
THE APPROACHING UPPER LEVEL TROUGH. THIS WILL INCREASE THE UPSLOPE
LOW LEVEL SOUTHEASTERLY FLOW EAST OF THE FRONT RANGE WITH ADVECTION
OF 50+ DEGREE DEW POINT AIRMASS. THE NAM AND SREF DEPICT A CORRIDOR
OF MODERATE INSTABILITY /MLCAPES 1500-2000 J/KG AND LI/S TO -6C/
WITH 30-40 KT OF DEEP LAYER SHEAR EAST OF THE LARAMIE RANGE INTO THE
NEBRASKA PANHANDLE. THE STORM PREDICTION CENTER HAS THIS AREA
HIGHLIGHTED BY A SLIGHT RISK OF SEVERE TSTORMS WITH DAMAGING WINDS
AND LARGE HAIL THE PRIMARY THREATS. A FEW WEAK TORNADOES WILL BE
POSSIBLE AS WELL. CONVECTION SHOULD DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE EARLY THIS AFTERNOON AND INTENSIFY AS THEY MOVE EAST
ONTO THE HIGH PLAINS LATER THIS AFTERNOON. THE SEVERE WEATHER THREAT
WILL END AFTER MID EVENING IN THE EAST WITH LOSS OF DAYTIME HEATING.

SHOWERS AND ISOLATED TSTORMS WILL LINGER TONIGHT AND WEDNESDAY AS
THE UPPER LEVEL TROUGH AXIS SWINGS NORTHEAST ACROSS THE FRONT RANGE
AND HIGH PLAINS. THE MODELS INDICATE THAT THE AXIS OF INSTABILITY
WILL SHIFT EAST INTO THE CENTRAL PLAINS...WITH THE SEVERE WEATHER
THREAT EAST OF OUR PANHANDLE COUNTIES. SHOWER CHANCES TAPER OFF
FROM SOUTHWEST TO NORTHEAST WITH THE PASSAGE OF THE UPPER TROUGH
WEDNESDAY NIGHT.

700MB TEMPERATURES THIS AFTERNOON PEAK BETWEEN 7 AND 9C...YIELDING
HIGHS IN THE 70S TO AROUND 80 LOWER ELEVATIONS...WITH 50S AND 60S
FOR THE HIGH COUNTRY. EXPECT ANOTHER MILD NIGHT WITH LOWS IN THE
40S AND 50S OUTSIDE THE MOUNTAINS. A PACIFIC FRONT WILL MOVE EAST
ACROSS THE CWFA EARLY WEDNESDAY. 700MB TEMPERATURES WILL BE 3 TO
5C COOLER WEDNESDAY AFTERNOON. HIGHS WILL RANGE FROM THE 60S TO
LOWER 70S LOWER ELEVATIONS...TO THE 40S AND 50S HIGH COUNTRY.
LOWS WEDNESDAY NIGHT WILL BE IN THE 40S WITH 30S FOR THE MOUNTAINS.
THE SNOW LEVEL WILL DROP TO AROUND 9000 FT WEDNESDAY NIGHT...WITH
LIGHT ACCUMULATIONS FROM SNOW SHOWERS.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 227 AM MDT TUE MAY 28 2013

UPPER LEVEL TROUGH WILL BE THE MAIN WEATHER MAKER THROUGH SATURDAY
WITH TEMPERATURES A BIT BELOW NORMAL WITH CHANCES FOR SHOWERS AND
A FEW THUNDERSTORMS. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
LARGELY HINGE ON PLACEMENT OF SHORTWAVE ENERGY ROTATING THROUGH
WEST TO NORTHWEST FLOW. TIMING AND PLACEMENT OF THESE FEATURES
WILL BE TOUGH TO NAIL DOWN OVER THE NEXT SEVERAL DAYS...BUT AT
THIS TIME IT LOOKS LIKE NORTHERN PORTIONS OF THE FORECAST AREA
WILL SEE THE HIGHEST CHANCES FOR MEASURABLE PRECIPITATION.
GENERALLY EXPECTING SHOWERS WITH ISOLATED GARDEN VARIETY
THUNDERSTORMS WITH WEAK INSTABILITY AND LITTLE CAPE TO WORK WITH.
HIGHS WILL MAINLY BE IN THE 60S THURSDAY THROUGH SATURDAY.

UPPER LEVEL TROUGH SHOULD PUSH EAST OF THE AREA BY SUNDAY WITH
RIDGING ACROSS THE WESTERN CONUS. THIS MEANS A RETURN OF WARMER
TEMPERATURES...ALONG WITH DRY CONDITIONS AND MINIMAL CLOUDS COVER.
HIGHS SHOULD PUSH INTO THE 70S ACROSS MOST OF THE AREA SUNDAY.
HOWEVER BY MONDAY...MAY BE BACK INTO THE 80S OVER THE NEBRASKA
PANHANDLE AND PORTIONS OF SOUTHEAST WYOMING.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1121 AM MDT TUE MAY 28 2013

MAINLY VFR OVER THE TERMINALS TODAY AND TONIGHT OUTSIDE OF WIDELY
SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING...INITIALLY OVER
THE MOUNTAINS AND THEN THE LOWER ELEVATIONS AND PLAINS BY LATE IN
THE AFTERNOON. BRIEF MVFR/IFR CIGS AND VSBYS POSSIBLE IN THE STORMS
ALONG WITH GUSTY WINDS.  SOME LOW CLOUDS POSSIBLE AGAIN LATER
TONIGHT OVER THE PANHANDLE.

&&

.FIRE WEATHER...
ISSUED AT 227 AM MDT TUE MAY 28 2013

CHANCES FOR MORE WIDESPREAD RAINFALL WILL INCREASE DURING THE NEXT
24 TO 48 HOURS AS A UPPER LEVEL TROUGH OF LOW PRESSURE MOVES ACROSS
THE CENTRAL ROCKIES AND ADJACENT PLAINS. FUELS IN GREEN UP STAGE...
COOLER TEMPERATURES AND HIGHER RELATIVE HUMIDITIES WILL RESULT IN
LOW FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. WARMER AND
DRIER CONDITIONS WILL RETURN EARLY NEXT WEEK.

&&

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

SHORT TERM...JAMSKI
LONG TERM...LIEBL
AVIATION...LIEBL
FIRE WEATHER...JAMSKI

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
1121 AM MDT TUE MAY 28 2013

WYZ101>119-291730-
CONVERSE COUNTY LOWER ELEVATIONS-NIOBRARA COUNTY-
NORTH LARAMIE RANGE-FERRIS/SEMINOE/SHIRLEY MOUNTAINS-
SHIRLEY BASIN-CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY-
EAST PLATTE COUNTY-GOSHEN COUNTY-CENTRAL CARBON COUNTY-
NORTH SNOWY RANGE FOOTHILLS-SOUTHWEST CARBON COUNTY-
SIERRA MADRE RANGE-UPPER NORTH PLATTE RIVER BASIN-SNOWY RANGE-
LARAMIE VALLEY-SOUTH LARAMIE RANGE-SOUTH LARAMIE RANGE FOOTHILLS-
CENTRAL LARAMIE COUNTY-EAST LARAMIE COUNTY-
1121 AM MDT TUE MAY 28 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST WYOMING.

.DAY ONE...THIS AFTERNOON AND TONIGHT

ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP IN THE AFTERNOON
TODAY. A FEW STRONG THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND
THIS EVENING ACROSS THE EASTERN PLAINS OF WYOMING. LARGE
HAIL...FREQUENT LIGHTNING...AND STRONG GUSTY WINDS ARE THE MAIN
THREATS FROM THESE THUNDERSTORMS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

WIDELY SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS ARE
FORECAST WEDNESDAY AND THURSDAY. THE PROBABILITY OF SEVERE
WEATHER WILL BE LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED FROM MID AFTERNOON THROUGH
MID EVENING EAST OF THE LARAMIE RANGE DUE TO THE POSSIBILITY OF
SEVERE THUNDERSTORMS.

&&

THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND
CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT...
HTTP://WEATHER.GOV/CHEYENNE

NEZ002-003-019>021-054-055-095-096-291730-
DAWES-BOX BUTTE-SCOTTS BLUFF-BANNER-MORRILL-KIMBALL-CHEYENNE-
NORTH SIOUX-SOUTH SIOUX-
1121 AM MDT TUE MAY 28 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN NEBRASKA
PANHANDLE.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS WILL MOVE EAST OF THE LARAMIE RANGE
DURING THE MID TO LATE AFTERNOON. SOME OF THE THUNDERSTORMS MAY
PRODUCE LARGE HAIL AND DAMAGING WIND GUSTS. ISOLATED TORNADOES
WILL ALSO BE POSSIBLE. THE THUNDERSTORMS WILL DIMINISH AND MOVE
EAST OF THE REGION LATE TONIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

WIDELY SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS ARE
FORECAST WEDNESDAY AND THURSDAY. THE PROBABILITY OF SEVERE
WEATHER WILL BE LOW...ALTHOUGH A FEW STRONGER STORMS ARE POSSIBLE
WEDNESDAY EVENING ACROSS WESTERN NEBRASKA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED FROM MID AFTERNOON THROUGH
MID EVENING DUE TO THE POSSIBILITY OF SEVERE THUNDERSTORMS.

&&

THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND
CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT...
HTTP://WEATHER.GOV/CHEYENNE

TT

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
215 PM MDT TUE MAY 28 2013

NEZ019-096-282115-
SCOTTS BLUFF NE-SOUTH SIOUX NE-
215 PM MDT TUE MAY 28 2013

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN SIOUX AND NORTHWESTERN
SCOTTS BLUFF COUNTIES UNTIL 315 PM MDT...

AT 213 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR MORRILL...OR 15 MILES EAST OF TORRINGTON...
MOVING NORTH AT 25 MPH.

HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM.

THIS STORM WILL BE NEAR...
RURAL SOUTHERN SIOUX COUNTY THROUGH 315 PM MDT
RURAL CENTRAL SIOUX COUNTY THROUGH 315 PM MDT

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

&&

LAT...LON 4242 10401 4234 10346 4196 10386 4200 10400
TIME...MOT...LOC 2015Z 197DEG 22KT 4202 10390

RUBIN