Alert archive / Wyoming / Special Weather Statements in 2021
Special Weather Statement, NWS Cheyenne, WY
NWS Cheyenne, WY issued this special weather statement at Jun 13, 2021, 3:31 PM MDT for Platte County, Wyoming. It was in force for 29 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jun 13, 2021, 3:31 PM MDT (21:31 UTC)
- Expired
- Jun 13, 2021, 4:00 PM MDT
- In force
- 29 min
- Issued by
- NWS Cheyenne, WY
County Platte County, WY
The radar
The Cheyenne radar (KCYS), 71 km from the middle of the area, began a volume at 21:31 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Denver, CO (KDNR), launched 12:00Z, 9.5 hours before the alert went out and 249 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 827 J/kg
- Mixed-layer CIN
- -387 J/kg
- Mixed-layer LCL
- 1858 m above ground
- 0-6 km bulk shear
- 8 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 10 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
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</html>What forecasters said that day
The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Cheyenne, WY wrote its last area forecast discussion before this special weather statement went out at Jun 13, 3:17 PM MDT, 14 minutes earlier.
Area forecast discussion, Jun 13, 3:17 PM MDT, 14 minutes before
Area Forecast Discussion National Weather Service Cheyenne WY 317 PM MDT Sun Jun 13 2021 .UPDATE... Issued at 314 PM MDT Sun Jun 13 2021 Severe Thunderstorm Watch 268 has been issued for southeast Wyoming and Nebraska Panhandle through 04Z tonight. Updates have been sent. && .SHORT TERM...(This evening through Monday) Issued at 240 PM MDT Sun Jun 13 2021 Forecast challenges deal with severe thunderstorms today. Currently...thunderstorms developing along the Laramie Range this afternoon. Surface trough lays from near Cheyenne to Torrington with moist southeasterly upslope flow in the lower layers. Cold front being analyzed across central South Dakota back into northeastern Wyoming. SPC Mesoanalysis showing EMC RAP surface based CAPE around 5000 J/KG out in the Panhandle and around 2500 J/KG where the storms are forming on the Laramie Range. Still some small capping across southeast Wyoming with around 50 J/KG convective inhibition. Main limiting factor right now is lack of shear. Later this afternoon...northern front drops south into the northern Panhandle and Converse County in east central Wyoming. Sfc to 6km shear increases to 35kts across the northern Panhandle to around 50kts down here near Cheyenne. HRRR and NAMNEST short term guidance forecasting showers blossoming along the front as it slowly drops south southwestward into the southern Panhandle and southeast Wyoming plains. Could be a long show tonight as both models continue showers and storms through 09Z. SPC showing a Day 2 Marginal Risk area for the Nebraska Panhandle for Monday afternoon. Latest guidance showing no PoPs over that area for Monday. But with dewpoints in the 60s...surface boundary in the Panhandle and a weak upper southwest dropping shortwave...decided to add low chance PoPs for the Panhandle. and .LONG TERM...(Monday night through Saturday) Issued at 323 AM MDT Sun Jun 13 2021 Monday, the moisture sticks around the Nebraska panhandle with PWATs around 1.00 in through the afternoon. Daytime heating will still be strong with the upper-level ridge holding strong over northwest Wyoming, so the panhandle is still conducive to thunderstorms, but confidence is lower for Monday's convection. Tuesday, the ridge begins to erode, turning our winds back to westerly/southwesterly, advecting warmer, drier air into southeast Wyoming and western Nebraska. Afternoon highs for Tuesday and Wednesday are in the 90s to 100 degrees for some areas with humidities dropping to the teens and lower 20s. Winds should remain between 5 and 15 knots, but with the temperatures being so high and the air being so dry, there is still elevated fire weather conditions. Finally Thursday we begin to see a downward trend in temperatures as winds turn northwesterly. Afternoon highs are still expected to be in the 80s to lower 90s through the weekend though, with overnight lows in the 50s and 60s. Next chance of precipitation after Monday will be Friday afternoon. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) Issued at 1126 AM MDT Sun Jun 13 2021 Wyoming TAFS...VFR. Thunderstorms in the vicinity at Cheyenne from 21Z to 03Z. Wind gusts to 22 knots at Laramie and Cheyenne until 03Z. Nebraska TAFS...VFR. Thunderstorms in the vicinity from 21Z to 07Z. Wind gusts to 28 knots at Alliance, Scottsbluff and Sidney until 02Z. && .FIRE WEATHER... Issued at 240 PM MDT Sun Jun 13 2021 High pressure over the Rockies will keep temperatures above normal and very dry humidity over the next several days. Increasingly warmer temperatures and single digit afternoon humidities from the Laramie Range west. Until fuels are turned over to YES on rapid fire spread...fire weather conditions will remain below critical levels. A windy day expected Wednesday into Thursday across Carbon and Albany Counties....with afternoon humidity in the single digits. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && UPDATE...GCC SHORT TERM...GCC LONG TERM...LK AVIATION...RUBIN FIRE WEATHER...GCC
Hazardous weather outlook, Jun 13, 4:25 AM MDT, 11 hours 6 minutes before
Hazardous Weather Outlook National Weather Service Cheyenne WY 425 AM MDT Sun Jun 13 2021 WYZ104-105-109>115-141030- Ferris/Seminoe/Shirley Mountains-Shirley Basin- Central Carbon County-North Snowy Range Foothills- Southwest Carbon County-Sierra Madre Range- Upper North Platte River Basin-Snowy Range-Laramie Valley- 425 AM MDT Sun Jun 13 2021 This hazardous weather outlook is for portions of south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT Very warm temperatures and dry conditions will maintain elevated fire weather concerns. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY Very warm temperatures and dry conditions will maintain elevated fire weather concerns. .Spotter information statement... Spotter activation will not be needed. NEZ002-003-019>021-054-055-095-096-WYZ101>103-106>108-116>119- 141030- Dawes County-Box Butte County-Scotts Bluff County-Banner County- Morrill County-Kimball County-Cheyenne County- Northern Sioux County-Southern Sioux County- Converse County Lower Elevations-Niobrara County- North Laramie Range- Central Laramie Range and Southwest Platte County- East Platte County-Goshen County-South Laramie Range- South Laramie Range Foothills-Central Laramie County- East Laramie County- 425 AM MDT Sun Jun 13 2021 This hazardous weather outlook is for portions of panhandle Nebraska...east central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT Chances of showers and strong to briefly severe thunderstorm Sunday afternoon through late Sunday night. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY The probability for widespread hazardous weather is low. .Spotter information statement... Spotter activation will not be needed.
In the hours before
Special weather statement, Jun 13, 1:49 PM MDT, 1 hour 42 minutes before
Special Weather Statement National Weather Service Cheyenne WY 149 PM MDT Sun Jun 13 2021 WYZ116-117-132030- South Laramie Range WY-South Laramie Range Foothills WY- 149 PM MDT Sun Jun 13 2021 ...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL LARAMIE COUNTY UNTIL 230 PM MDT... At 148 PM MDT, Doppler radar was tracking a strong thunderstorm over Horse Creek, or 23 miles east of Laramie, moving northeast at 10 mph. Penny size hail and winds in excess of 40 mph will be possible with this storm. This storm will remain over mainly rural areas of west central Laramie County. LAT...LON 4134 10526 4141 10527 4154 10509 4138 10496 TIME...MOT...LOC 1948Z 236DEG 9KT 4141 10516 Rubin
Special weather statement, Jun 13, 2:44 PM MDT, 47 minutes before
Special Weather Statement National Weather Service Cheyenne WY 244 PM MDT Sun Jun 13 2021 WYZ106-116-117-132115- South Laramie Range WY- Central Laramie Range and Southwest Platte County WY- South Laramie Range Foothills WY- 244 PM MDT Sun Jun 13 2021 ...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL ALBANY... NORTHWESTERN LARAMIE AND SOUTHWESTERN PLATTE COUNTIES UNTIL 315 PM MDT... At 244 PM MDT, Doppler radar was tracking a strong thunderstorm near Iron Mountain, or 28 miles northeast of Laramie, moving north at 20 mph. Penny size hail and wind gusts up to 50 mph will be possible with this storm. Locations impacted include... Iron Mountain. PRECAUTIONARY/PREPAREDNESS ACTIONS... 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. && LAT...LON 4151 10507 4152 10530 4184 10534 4182 10498 TIME...MOT...LOC 2044Z 183DEG 17KT 4160 10518 Hammer
Special weather statement, Jun 13, 3:12 PM MDT, 19 minutes before
Special Weather Statement National Weather Service Cheyenne WY 312 PM MDT Sun Jun 13 2021 WYZ106-115>117-132145- South Laramie Range WY- Central Laramie Range and Southwest Platte County WY- South Laramie Range Foothills WY-Laramie Valley WY- 312 PM MDT Sun Jun 13 2021 ...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL ALBANY AND NORTHWESTERN LARAMIE COUNTIES UNTIL 345 PM MDT... At 312 PM MDT, Doppler radar was tracking a strong thunderstorm near Baldy Peak, or 17 miles northeast of Laramie. This storm was nearly stationary. Penny size hail and wind gusts up to 50 mph will be possible with this storm. Locations impacted include... Baldy Peak. PRECAUTIONARY/PREPAREDNESS ACTIONS... 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 1000 PM MDT for southeastern Wyoming. LAT...LON 4145 10551 4161 10552 4165 10522 4144 10522 TIME...MOT...LOC 2112Z 263DEG 2KT 4154 10542 Hammer
Special weather statement, Jun 13, 3:31 PM MDT, 0 minutes before
Special Weather Statement
National Weather Service Cheyenne WY
331 PM MDT Sun Jun 13 2021
WYZ106>108-132200-
East Platte County WY-
Central Laramie Range and Southwest Platte County WY-
Goshen County WY-
331 PM MDT Sun Jun 13 2021
...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL GOSHEN AND
SOUTHEASTERN PLATTE COUNTIES UNTIL 400 PM MDT...
At 331 PM MDT, Doppler radar was tracking a strong thunderstorm over
Chugwater, or 20 miles south of Wheatland, moving northeast at 15
mph.
Half inch hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Chugwater and Slater.
This includes Interstate 25 in Wyoming between mile markers 50 and
65.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 1000 PM MDT for
southeastern Wyoming.
LAT...LON 4174 10496 4201 10479 4184 10448 4173 10464
4166 10476
TIME...MOT...LOC 2131Z 210DEG 13KT 4177 10482
HammerThe office that day
Everything else NWS Cheyenne, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 13, 1:49 PM MDT | Special Weather Statement | CYS | Laramie | 41 min |
| Jun 13, 2:44 PM MDT | Special Weather Statement | CYS | Albany | 31 min |
| Jun 13, 3:12 PM MDT | Special Weather Statement | CYS | Albany | 33 min |
| Jun 13, 3:57 PM MDT | Special Weather Statement | CYS | Goshen | 33 min |
| Jun 13, 4:31 PM MDT | Special Weather Statement | CYS | Goshen | 29 min |
| Jun 13, 4:53 PM MDT | Severe Thunderstorm Warning | CYS | Goshen | 32 min |
| Jun 13, 4:58 PM MDT | Severe Thunderstorm Warning | CYS | Laramie | 47 min |
| Jun 13, 5:13 PM MDT | Severe Thunderstorm Warning | CYS | Goshen | 47 min |
| Jun 13, 5:16 PM MDT | Special Weather Statement | CYS | Laramie | 44 min |
| Jun 13, 5:43 PM MDT | Severe Thunderstorm Warning | CYS | Laramie | 41 min |
| Jun 13, 5:31 PM MDT | Special Weather Statement | CYS | Dawes | 44 min |
| Jun 13, 5:50 PM MDT | Severe Thunderstorm Warning | CYS | Box Butte, Dawes, Sioux | 55 min |
| Jun 13, 5:58 PM MDT | Severe Thunderstorm Warning | CYS | Scotts Bluff, Sioux | 47 min |
Nearby
Special Weather Statements in Wyoming, 2021Every special weather statement in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.