Severe Thunderstorm Warning 172, NWS Cheyenne, WY

473 
WWUS55 KCYS 262235
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
435 PM MDT THU JUL 26 2018

WYC001-262300-
/O.CON.KCYS.SV.W.0172.000000T0000Z-180726T2300Z/
Albany WY-
435 PM MDT THU JUL 26 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM MDT
FOR EAST CENTRAL ALBANY COUNTY...

At 435 PM MDT, a severe thunderstorm was located 9 miles north of
Wheatland Reservoir 3, or 42 miles west of Wheatland, moving
southeast at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

This severe thunderstorm will remain over mainly rural areas of east
central Albany County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4182 10575 4195 10552 4179 10528 4158 10556
TIME...MOT...LOC 2235Z 312DEG 20KT 4202 10578 

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

Lyons

Area Forecast Discussion
National Weather Service Cheyenne WY
237 PM MDT Thu Jul 26 2018

.SHORT TERM...(This evening through Friday)
Issued at 300 PM MDT Thu Jul 26 2018

Severe weather ongoing across southeast Wyoming as we get an early
start today. Forecast challenges deal with severe convection and
possibility of heavy rain both today and Friday.

Currently...Water vapor imagery showing an upper level shortwave
tracking into the CWFA that has kicked off convection. SPC
Mesoanalysis page showing an uncapped environment with surface
based CAPE around 2000-2500J/KG already this afternoon at 2PM.
Bulk shear around 40-45kts as well. Both CAPE and shear are
expected to continue increasing through the rest of the afternoon.
CAPE expected to peak out around 3000-3500 J/KG at 6PM and bulk
shear increases to 50-55kts. Large hail, damaging winds and a few
tornadoes can not be ruled out. PWATs in excess of 1 inch continue
across our eastern counties through the afternoon, so existing
Flash Flood Watch will remain in effect. HRRR continues to show
pretty strong cells across the area through roughly 03Z before
beginning to ease.

Forecast still on track for severe weather Friday as another
shortwave tracks into the Nebraska Panhandle. ECMWF continues to
show the best area for severe storms Friday to be over the
Panhandle where SPC has an Enhanced Risk for severe storms. Heavy
rainfall expected out there Friday, so later shifts will need to
consider another Flash Flood Watch once again.

.LONG TERM...(Friday night through Thursday)
Issued at 307 AM MDT Thu Jul 26 2018

The wet and unsettled conditions will remain over the area
Saturday through Sunday with a pretty good push of cool air for
late July arriving Sunday. Scattered to numerous showers and
storms will continue both days. Drying should then ensue late
Sunday in the wake of a stronger shortwave that will move south
from the northern plains and cut off the monsoonal moisture for a
time. Monday through Weds should see warming temperatures back to
near seasonal averages along with mainly dry conditions under a
persistent northwesterly flow aloft.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 540 AM MDT Thu Jul 26 2018

The main concerns today will be the thunderstorm chances. Latest
water vapor loop was showing a shortwave moving through southeast
Montana. This feature may trigger a few thunderstorms late this
morning in northeast Wyoming. However, the main activity is
expected to develop mainly after 21z this afternoon as stronger
jet energy crosses over the Laramie Range. This will create
scattered strong to severe thunderstorms. These storms will
generally move southeast around 25kts, but a few of these storms
could deviate and split. These storms may contain strong wind
gusts and hail up to quarter size. The thunderstorms should move
out of the Nebraska panhandle by 03-04z with clearing skies
expected overnight. Not confident about seeing low clouds or fog
at this juncture.
&&

.FIRE WEATHER...
Issued at 300 PM MDT Thu Jul 26 2018

Minimal fire weather concerns over the next few days as monsoon
moisture remains in place. Widespread wetting rains expected with
well above critical humidity in the afternoon. Expect showers and
thunderstorms to continue through Sunday, before drying commences
next week. Until then, fire weather threats will remain low.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Flash Flood Watch until 10 PM MDT this evening for WYZ108-118-
     119.

NE...Flash Flood Watch until 10 PM MDT this evening for NEZ003-
     019>021-054-055-096.

&&

SHORT TERM...GCC
LONG TERM...RE
AVIATION...JG
FIRE WEATHER...GCC

Hazardous Weather Outlook
National Weather Service Cheyenne WY
1014 AM MDT Thu Jul 26 2018

NEZ002-003-019>021-054-055-095-096-WYZ101-102-107-108-117>119-
271615-
Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Kimball-Cheyenne-
North Sioux-South Sioux-Converse County Lower Elevations-
Niobrara County-East Platte County-Goshen County-
South Laramie Range Foothills-Central Laramie County-
East Laramie County-
1014 AM MDT Thu Jul 26 2018

This hazardous weather outlook is for portions of western
Nebraska...east central Wyoming and southeast Wyoming.

.DAY ONE...TODAY AND TONIGHT

Scattered to numerous showers and thunderstorms are expected to
initially develop around the mountains early this afternoon then
move out over the plains through this evening. Strong to severe
storms are possible with large hail and very strong downburst
winds the main threat. Heavy rainfall can be expected with some of
these storms and a Flash Flood Watch has been issued for areas
along and south of a line from Alliance to Torrington to Cheyenne
from 4 PM to 10 PM this evening.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

Scattered showers and storms will continue to be likely through
Sunday. Some strong storms remain possible Friday and Saturday.

.Spotter information statement...

Spotter activation will be needed along and south of an Alliance
to Torrington to Cheyenne line after 3 PM today.

WYZ103>106-109>116-271615-
North Laramie Range-Ferris/Seminoe/Shirley Mountains-
Shirley Basin-Central Laramie Range and Southwest Platte 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-
1014 AM MDT Thu Jul 26 2018

This hazardous weather outlook is for portions of south central
Wyoming and southeast Wyoming.

.DAY ONE...TODAY AND TONIGHT

Widely scattered showers and storms should move across the area
this afternoon into early this evening. Severe storms are not
expected.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

Widely scattered showers and storms will continue to be likely
through Sunday.

.Spotter information statement...

Spotter activation will not be needed.

Special Weather Statement
National Weather Service Cheyenne WY
245 PM MDT THU JUL 26 2018

WYZ104-109-262130-
Central Carbon County WY-Ferris/Seminoe/Shirley Mountains WY-
245 PM MDT THU JUL 26 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL CARBON COUNTY UNTIL
330 PM MDT...

At 245 PM MDT, Doppler radar was tracking a strong thunderstorm 9
miles south of Devil's Gate, or 34 miles east of Jeffrey City, moving
east at 25 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.

This storm will remain over mainly rural areas of north central
Carbon County.

LAT...LON 4244 10705 4243 10674 4218 10669 4220 10730
      4238 10732
TIME...MOT...LOC 2045Z 266DEG 23KT 4230 10721

Lyons

Special Weather Statement
National Weather Service Cheyenne WY
258 PM MDT THU JUL 26 2018

WYZ101-262145-
Converse County Lower Elevations WY-
258 PM MDT THU JUL 26 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN CONVERSE COUNTY
UNTIL 345 PM MDT...

At 258 PM MDT, Doppler radar was tracking a strong thunderstorm 17
miles southeast of Pine Tree Junction, or 19 miles south of Wright,
moving southeast at 15 mph.

Half inch hail and wind gusts up to 50 mph will be possible with this
storm.

This storm will remain over mainly rural areas of northeastern
Converse County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
east central Wyoming.

LAT...LON 4330 10507 4315 10564 4350 10569 4350 10536
TIME...MOT...LOC 2058Z 322DEG 14KT 4346 10551

Lyons

Special Weather Statement
National Weather Service Cheyenne WY
331 PM MDT THU JUL 26 2018

WYZ104-105-262215-
Shirley Basin WY-Ferris/Seminoe/Shirley Mountains WY-
331 PM MDT THU JUL 26 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN CARBON COUNTY UNTIL
415 PM MDT...

At 331 PM MDT, Doppler radar was tracking a strong thunderstorm 8
miles northwest of Seminoe Dam, or 33 miles north of Rawlins, moving
east at 30 mph.

Dime size hail and wind gusts up to 50 mph will be possible with this
storm.

This storm will remain over mainly rural areas of northeastern Carbon
County.

LAT...LON 4243 10680 4244 10663 4243 10628 4219 10623
      4217 10682
TIME...MOT...LOC 2131Z 261DEG 25KT 4224 10700

Lyons

Special Weather Statement
National Weather Service Cheyenne WY
338 PM MDT THU JUL 26 2018

WYZ101-102-262230-
Converse County Lower Elevations WY-Niobrara County WY-
338 PM MDT THU JUL 26 2018

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL NIOBRARA AND
NORTHEASTERN CONVERSE COUNTIES UNTIL 430 PM MDT...

At 338 PM MDT, Doppler radar was tracking a strong thunderstorm near
Bill, or 32 miles north of Douglas, moving southeast at 35 mph.

Half inch hail and wind gusts up to 50 mph will be possible with this
storm.

Locations impacted include...
Bill and Manning Ranch.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
east central Wyoming.

LAT...LON 4325 10549 4334 10523 4290 10477 4276 10525
TIME...MOT...LOC 2138Z 332DEG 30KT 4323 10534

Lyons

Special Weather Statement
National Weather Service Cheyenne WY
345 PM MDT THU JUL 26 2018

WYZ103-106-262230-
Central Laramie Range and Southwest Platte County WY-
North Laramie Range WY-
345 PM MDT THU JUL 26 2018

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL ALBANY AND
SOUTHWESTERN PLATTE COUNTIES UNTIL 430 PM MDT...

At 344 PM MDT, Doppler radar was tracking a strong thunderstorm 11
miles southeast of Laramie Peak, or 20 miles west of Wheatland,
moving southeast at 20 mph.

Dime size hail and wind gusts up to 50 mph will be possible with this
storm.

Locations impacted include...
Westview Circle.

This includes Interstate 25 in Wyoming near mile marker 71.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
southeastern Wyoming.

LAT...LON 4212 10549 4223 10530 4193 10493 4177 10523
TIME...MOT...LOC 2144Z 324DEG 18KT 4212 10534

Lyons

Special Weather Statement
National Weather Service Cheyenne WY
359 PM MDT THU JUL 26 2018

WYZ103-105-106-115>117-262300-
Shirley Basin WY-South Laramie Range WY-
Central Laramie Range and Southwest Platte County WY-
North Laramie Range WY-South Laramie Range Foothills WY-
Laramie Valley WY-
359 PM MDT THU JUL 26 2018

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL ALBANY...
NORTHWESTERN LARAMIE AND SOUTHWESTERN PLATTE COUNTIES UNTIL 500 PM
MDT...

At 358 PM MDT, Doppler radar was tracking a strong thunderstorm near
Wheatland Reservoir 3, or 41 miles west of Wheatland, moving
southeast at 35 mph.

A second strong thunderstorm was located 35 miles west northwest of
Chugwater moving southeast at 35 mph.

Half inch hail and wind gusts up to 50 mph will be possible with
these storm.

Locations impacted include...
Iron Mountain, Wheatland Reservoir 3 and Baldy Peak.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
southeastern Wyoming.

LAT...LON 4197 10591 4207 10589 4208 10572 4193 10536
      4178 10524 4165 10503 4136 10542
TIME...MOT...LOC 2158Z 321DEG 30KT 4197 10575

Lyons