Alert archive / Wyoming / Flash Flood Watches in 2021
Flash Flood Watch 1, NWS Cheyenne, WY
NWS Cheyenne, WY issued this flash flood watch at Jul 29, 2021, 2:01 PM MDT for 6 counties in Wyoming. It took effect at Jul 30, 2021, 11:00 AM MDT. It was in force for 13 hr.
The area
The counties it named.
The facts
- Issued
- Jul 29, 2021, 2:01 PM MDT (20:01 UTC)
- In effect from
- Jul 30, 2021, 11:00 AM MDT
- Expired
- Jul 30, 2021, 11:35 PM MDT
- In force
- 13 hr
- Issued by
- NWS Cheyenne, WY
- Flood severity
- None
Counties Albany County, WY, Carbon County, WY, Converse County, WY, Goshen County, WY, Laramie County, WY, Platte County, WY
The radar
The Cheyenne radar (KCYS), 103 km from the middle of the area, began a volume at 20:02 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
Riverton, WY (KRIW), launched 12:00Z, 8.0 hours before the alert went out and 277 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1746 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- 9 m²/s²
- 0-3 km storm-relative helicity
- 90 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
142 WGUS65 KCYS 292001 FFACYS URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Cheyenne WY 201 PM MDT Thu Jul 29 2021 WYZ105-110-114>116-301200- /O.NEW.KCYS.FF.A.0001.210730T1700Z-210731T0100Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Shirley Basin-North Snowy Range Foothills-Snowy Range-Laramie Valley- South Laramie Range- Including the cities of Albany, Arlington, Buford, Laramie, Elk Mountain, Medicine Bow, Shirley Basin, Centennial, Vedauwoo, Pumpkin Vine, and Bosler 201 PM MDT Thu Jul 29 2021 ...FLASH FLOOD WATCH IN EFFECT FROM FRIDAY MORNING THROUGH FRIDAY EVENING... The National Weather Service in Cheyenne has issued a * Flash Flood Watch for portions of south central Wyoming and southeast Wyoming, including the following areas, in south central Wyoming, North Snowy Range Foothills, Shirley Basin and Snowy Range. In southeast Wyoming, Laramie Valley and South Laramie Range. * From Friday morning through Friday evening. * Monsoon moisture is expected to surge north out of Colorado tonight into Friday. Widespread showers and thunderstorms are expected to develop through the late morning hours and persist through the afternoon and evening hours Friday. These storms are expected to be slow moving and will produce heavy rainfall over some areas. * Hikers and campers in the Snowy and Laramie Ranges can expect rapid water rises on area streams. Drainage and low areas are very susceptible to flash flooding from rapid water rises. If camping or hiking in these areas...have a way to receive future updates to the watch and monitor weather conditions. Mullen Burn Scar may see mudslides and flash flooding with very little rainfall. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Claycomb
4 follow-up statements
414 WGUS65 KCYS 300845 FFACYS URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Cheyenne WY 245 AM MDT Fri Jul 30 2021 WYZ105-110-114>116-310600- /O.EXT.KCYS.FF.A.0001.210730T1700Z-210731T0600Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Shirley Basin-North Snowy Range Foothills-Snowy Range-Laramie Valley- South Laramie Range- Including the cities of Albany, Arlington, Buford, Laramie, Elk Mountain, Medicine Bow, Shirley Basin, Centennial, Vedauwoo, Pumpkin Vine, and Bosler 245 AM MDT Fri Jul 30 2021 ...FLASH FLOOD WATCH NOW IN EFFECT FROM 11 AM MDT THIS MORNING THROUGH THIS EVENING... The Flash Flood Watch is now in effect for * Portions of south central Wyoming and southeast Wyoming, including the following areas, in south central Wyoming, North Snowy Range Foothills, Shirley Basin and Snowy Range. In southeast Wyoming, Laramie Valley and South Laramie Range. * From 11 AM MDT this morning through this evening. * Monsoon moisture is expected to surge north out of Colorado today. Widespread showers and thunderstorms are expected to develop through the late morning hours and persist through the afternoon and evening hours today. These storms are expected to be slow moving and will produce heavy rainfall over some areas. * Hikers and campers in the Snowy and Laramie Ranges can expect rapid water rises on area streams. Drainage and low areas are very susceptible to flash flooding from rapid water rises. If camping or hiking in these areas...have a way to receive future updates to the watch and monitor weather conditions. Mullen Burn Scar may see mudslides and flash flooding with very little rainfall. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Rubin
474 WGUS65 KCYS 301557 FFACYS URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Cheyenne WY 957 AM MDT Fri Jul 30 2021 WYZ103-106-107-117-310600- /O.EXA.KCYS.FF.A.0001.210730T1700Z-210731T0600Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ North Laramie Range-Central Laramie Range and Southwest Platte County-East Platte County-South Laramie Range Foothills- Including the cities of Horse Creek, Esterbrook, Federal, Garrett, Wheatland, Guernsey, Bordeaux, and Whitaker 957 AM MDT Fri Jul 30 2021 ...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING... The National Weather Service in Cheyenne has expanded the * Flash Flood Watch to include a portion of southeast Wyoming, including the following areas, Central Laramie Range and Southwest Platte County, East Platte County, North Laramie Range and South Laramie Range Foothills. * Through this evening. * Monsoon moisture is expected to surge north out of Colorado today. Widespread showers and thunderstorms are expected to develop through the late morning hours and persist through the afternoon and evening hours today. These storms are expected to be slow moving and will produce heavy rainfall over some areas. * Hikers and campers in the Laramie Range can expect rapid water rises on area streams. Drainage and low areas are very susceptible to flash flooding from rapid water rises. If camping or hiking in these areas...have a way to receive future updates to the watch and monitor weather conditions. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ WYZ105-110-114>116-310600- /O.CON.KCYS.FF.A.0001.210730T1700Z-210731T0600Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Shirley Basin-North Snowy Range Foothills-Snowy Range-Laramie Valley- South Laramie Range- Including the cities of Albany, Arlington, Buford, Laramie, Elk Mountain, Medicine Bow, Shirley Basin, Centennial, Vedauwoo, Pumpkin Vine, and Bosler 957 AM MDT Fri Jul 30 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS EVENING... The Flash Flood Watch continues for * Portions of south central Wyoming and southeast Wyoming, including the following areas, in south central Wyoming, North Snowy Range Foothills, Shirley Basin and Snowy Range. In southeast Wyoming, Laramie Valley and South Laramie Range. * Through this evening. * Monsoon moisture is expected to surge north out of Colorado today. Widespread showers and thunderstorms are expected to develop through the late morning hours and persist through the afternoon and evening hours today. These storms are expected to be slow moving and will produce heavy rainfall over some areas. * Hikers and campers in the Snowy and Laramie Ranges can expect rapid water rises on area streams. Drainage and low areas are very susceptible to flash flooding from rapid water rises. If camping or hiking in these areas...have a way to receive future updates to the watch and monitor weather conditions. Mullen Burn Scar may see mudslides and flash flooding with very little rainfall. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Claycomb
048 WGUS65 KCYS 302028 FFACYS URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Cheyenne WY 228 PM MDT Fri Jul 30 2021 WYZ108-118-119-310600- /O.EXA.KCYS.FF.A.0001.000000T0000Z-210731T0600Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Goshen County-Central Laramie County-East Laramie County- Including the cities of Pine Bluffs, Cheyenne, and Torrington 228 PM MDT Fri Jul 30 2021 ...FLASH FLOOD WATCH IN EFFECT UNTIL MIDNIGHT MDT TONIGHT... The National Weather Service in Cheyenne has expanded the * Flash Flood Watch to include a portion of southeast Wyoming, including the following areas, Central Laramie County, East Laramie County and Goshen County. * Until Midnight MDT tonight. * Monsoon moisture continues to surge north out of Colorado this afternoon. Widespread showers and thunderstorms are expected to develop through the late afternoon hours and persist through the evening hours this evening. These storms are expected to be slow moving and will produce heavy rainfall over some areas. * Folks in low lying areas expect rapid water rises in drainage areas. Drainage and low areas are very susceptible to flash flooding from rapid water rises. Have a way to receive future updates to the watch and monitor weather conditions. Mullen Burn Scar may see mudslides and flash flooding with very little rainfall. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ WYZ103-105>107-110-114>117-310600- /O.CON.KCYS.FF.A.0001.000000T0000Z-210731T0600Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ North Laramie Range-Shirley Basin-Central Laramie Range and Southwest Platte County-East Platte County-North Snowy Range Foothills-Snowy Range-Laramie Valley-South Laramie Range-South Laramie Range Foothills- Including the cities of Horse Creek, Albany, Esterbrook, Federal, Arlington, Garrett, Buford, Laramie, Elk Mountain, Medicine Bow, Wheatland, Shirley Basin, Centennial, Guernsey, Vedauwoo, Bordeaux, Whitaker, Pumpkin Vine, and Bosler 228 PM MDT Fri Jul 30 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL MIDNIGHT MDT TONIGHT... The Flash Flood Watch continues for * Portions of south central Wyoming and southeast Wyoming, including the following areas, in south central Wyoming, North Snowy Range Foothills, Shirley Basin and Snowy Range. In southeast Wyoming, Central Laramie Range and Southwest Platte County, East Platte County, Laramie Valley, North Laramie Range, South Laramie Range and South Laramie Range Foothills. * Until Midnight MDT tonight. * Monsoon moisture is expected to surge north out of Colorado today. Widespread showers and thunderstorms are expected to develop through the afternoon hours and persist through the evening hours today. These storms are expected to be slow moving and will produce heavy rainfall over some areas. * Hikers and campers in the Snowy and Laramie Ranges can expect rapid water rises on area streams. Drainage and low areas are very susceptible to flash flooding from rapid water rises. If camping or hiking in these areas...have a way to receive future updates to the watch and monitor weather conditions. Mullen Burn Scar may see mudslides and flash flooding with very little rainfall. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Claycomb
327 WGUS65 KCYS 310535 FFACYS Flood Watch National Weather Service Cheyenne WY 1135 PM MDT Fri Jul 30 2021 WYZ103-105>108-110-114>119-310645- /O.CAN.KCYS.FF.A.0001.000000T0000Z-210731T0600Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ North Laramie Range-Shirley Basin-Central Laramie Range and Southwest Platte County-East Platte County-Goshen County-North Snowy Range Foothills-Snowy Range-Laramie Valley-South Laramie Range-South Laramie Range Foothills-Central Laramie County-East Laramie County- Including the cities of Horse Creek, Albany, Guernsey, Federal, Arlington, Garrett, Laramie, Elk Mountain, Medicine Bow, Cheyenne, Vedauwoo, Whitaker, Esterbrook, Buford, Torrington, Bordeaux, Bosler, Wheatland, Shirley Basin, Centennial, Pine Bluffs, and Pumpkin Vine 1135 PM MDT Fri Jul 30 2021 ...FLASH FLOOD WATCH IS CANCELLED... The Flash Flood Watch for portions of south central Wyoming and southeast Wyoming, including the following areas, in south central Wyoming, North Snowy Range Foothills, Shirley Basin and Snowy Range. In southeast Wyoming, Central Laramie County, Central Laramie Range and Southwest Platte County, East Laramie County, East Platte County, Goshen County, Laramie Valley, North Laramie Range, South Laramie Range and South Laramie Range Foothills has been cancelled. The Flood Watch is cancelled. Flooding is no longer expected to pose a threat. Please continue to heed remaining road closures. $$ Mokry
The office that day
Everything else NWS Cheyenne, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 29, 2:23 PM MDT | Flash Flood Warning | CYS | Albany, Carbon | 101 min |
| Jul 29, 2:27 PM MDT | Severe Thunderstorm Warning | CYS | Albany, Carbon | 48 min |
| Jul 29, 3:12 PM MDT | Severe Thunderstorm Warning | CYS | Albany, Carbon | 48 min |
| Jul 29, 3:19 PM MDT | Flash Flood Warning | CYS | Albany, Carbon | 104 min |
| Jul 29, 3:52 PM MDT | Severe Thunderstorm Warning | CYS | Albany | 38 min |
| Jul 29, 4:41 PM MDT | Areal Flood Advisory | CYS | Albany | 3 hr |
Nearby
Flash Flood Watches in Wyoming, 2021Every flash flood watch 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.