Alert archive / Idaho / Special Weather Statements in 2021
Special Weather Statement, NWS Pocatello, ID
NWS Pocatello, ID issued this special weather statement at Jul 30, 2021, 3:09 PM MDT for Cassia County, Idaho. It was in force for 51 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
- Jul 30, 2021, 3:09 PM MDT (21:09 UTC)
- Expired
- Jul 30, 2021, 4:00 PM MDT
- In force
- 51 min
- Issued by
- NWS Pocatello, ID
County Cassia County, ID
The radar
The Pocatello radar (KSFX), 98 km from the middle of the area, began a volume at 21:09 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
Elko, NV (KLKN), launched 12:00Z, 9.2 hours before the alert went out and 180 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
- 10 J/kg
- Mixed-layer CIN
- -189 J/kg
- Mixed-layer LCL
- 1966 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 15 m²/s²
- 0-3 km storm-relative helicity
- -39 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 Pocatello, ID wrote its last area forecast discussion before this special weather statement went out at Jul 30, 2:03 PM MDT, 1 hour 6 minutes earlier.
Area forecast discussion, Jul 30, 2:03 PM MDT, 1 hour 6 minutes before
Area Forecast Discussion National Weather Service Pocatello ID 203 PM MDT Fri Jul 30 2021 .SHORT TERM...Through Sunday. A low pressure system is advancing northward through Nevada this afternoon. An initial band of showers and thunderstorms associated with that low will affect the southeast highlands this afternoon and then spread southwestward into the south hills. This band of storms is separate from the disorganized isolated to scattered storms that we've seen over the past few days. Given the monsoon moisture entrenched across the region, locally heavy rain is possible with storms throughout the weekend as the low advances northward. Will issue flash flood watches targeting the high country across southeast Idaho into the south hills along with the central mountains. Although highly isolated flooding is possible elsewhere as well. The flash flood watch for the south hills and southeast Idaho will begin this afternoon to account for the initial wave of organized convection. This watch accounts for the Badger Fire burn scar near Oakley which is particularly vulnerable in this regime. As mentioned, the low advances north on Saturday to roughly southwest Oregon. Thunderstorms become more widespread across central and east Idaho. Although the flash flood watch for the central mountains begins this afternoon, the better threat begins Saturday. On Sunday, the low moves into Washington State and gains some upper level support as well. This will help to increase chances areawide. Heavy rain will continue to be possible. Although could be limited if there is residual cloud cover in place from decaying convection from the night before. 13 .LONG TERM...The storm system will begin lifting out on Monday. Continuing the flood watches as models still show thunderstorms around. Tuesday looks drier but another system arrives for mid to late week resulting in renewed chances for thunderstorms. && .AVIATION...Multiple rounds of showers and thunderstorms could impact our TAF sites in the next 24 hours. For now, we are carrying VCTS or VCSH and will amend as needed for direct impacts. IF a heavier shower or storm passes over a particular airport, MVFR to IFR conditions due to heavy rain could occur, along with wind gusts over 30kts and maybe small hail. Keyes && .FIRE WEATHER...A very moist sub-tropical flow will continue across the region through Monday. Multiple disturbances will produce several rounds of showers and thunderstorms into early next week. With this being a strong push of monsoon moisture, heavy rain and the potential for flooding/debris flows is there on recent burn scars or existing fires. Gusty winds over 35 mph and small are also possible with the stronger storms. Screaming message in all this, organized disturbances translating through moist sub-topical environments can produce very heavy rainfall events. Land managers operating in and around fires or burn scars should be extra attentive to developments this weekend. It looks like we cycle back into a drier SW flow/ridge pattern briefly Tuesday followed by a Pacific trough lifting through the region Thursday. Lots of moving parts here folks...stay tuned! Keyes/Huston && .PIH WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through Monday evening for IDZ056>064-069- 071>074. &&
In the hours before
Local storm report, Jul 30, 2:59 PM MDT, 10 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
259 PM MDT FRI JUL 30 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0230 PM HEAVY RAIN 2 NE POCATELLO 42.90N 112.44W
07/30/2021 M0.58 INCH BANNOCK ID TRAINED SPOTTER
&&
CMACKAYSpecial weather statement, Jul 30, 3:09 PM MDT, 0 minutes before
Special Weather Statement National Weather Service Pocatello ID 309 PM MDT Fri Jul 30 2021 IDZ057-302200- Raft River Region ID- 309 PM MDT Fri Jul 30 2021 ...SPECIAL WEATHER STATEMENT... At 308 PM MDT, Doppler radar was tracking a strong thunderstorm 7 miles northeast of Malta, moving north at 5 mph. Winds in excess of 30 mph will be possible with this storm. This storm will affect Interstate 84 near Yale Road in east central Cassia County. PRECAUTIONARY/PREPAREDNESS ACTIONS... Torrential rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 4224 11316 4231 11334 4247 11336 4236 11317 TIME...MOT...LOC 2108Z 184DEG 6KT 4237 11326 Valle
The office that day
Everything else NWS Pocatello, ID issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 30, 5:25 AM MDT | Special Weather Statement | PIH | Bear Lake | 50 min |
| Jul 30, 12:50 PM MDT | Areal Flood Advisory | PIH | Bannock | 22 min |
| Jul 30, 12:55 PM MDT | Flash Flood Watch | PIH | Bannock, Bear Lake, Bingham, Blaine, Bonneville, Butte and 10 more | 3 days |
| Jul 30, 1:12 PM MDT | Flash Flood Warning | PIH | Bannock | 108 min |
| Jul 30, 1:50 PM MDT | Flash Flood Warning | PIH | Bannock, Power | 115 min |
| Jul 30, 1:55 PM MDT | Areal Flood Advisory | PIH | Power | 2 hr |
| Jul 30, 1:57 PM MDT | Flash Flood Warning | PIH | Oneida | 2 hr |
| Jul 30, 2:19 PM MDT | Areal Flood Advisory | PIH | Power | 26 min |
| Jul 30, 2:24 PM MDT | Areal Flood Advisory | PIH | Bannock | 81 min |
| Jul 30, 2:38 PM MDT | Flash Flood Warning | PIH | Cassia | 3 hr |
| Jul 30, 2:45 PM MDT | Flash Flood Warning | PIH | Power | 90 min |
| Jul 30, 3:02 PM MDT | Flash Flood Warning | PIH | Cassia | 3 hr |
| Jul 30, 3:48 PM MDT | Areal Flood Advisory | PIH | Bonneville | 117 min |
| Jul 30, 5:17 PM MDT | Areal Flood Advisory | PIH | Blaine | 118 min |
Nearby
Special Weather Statements in Idaho, 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.