Alert archive / Idaho / Special Weather Statements in 2021

Special Weather Statement, NWS Missoula, MT

August 6, 2021Lemhi County, Idaho

NWS Missoula, MT issued this special weather statement at Aug 6, 2021, 5:32 PM MDT for Lemhi County, Idaho. It was in force for 43 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
Aug 6, 2021, 5:32 PM MDT (23:32 UTC)
Expired
Aug 6, 2021, 6:15 PM MDT
In force
43 min
Issued by
NWS Missoula, MT
Hail
0.00 in
Wind
40

County Lemhi County, ID

The radar

The Missoula radar (KMSX), 198 km from the middle of the area, began a volume at 23:35 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

Boise Airport, ID (KBOI), launched 12:00Z, 11.5 hours before the alert went out and 270 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.

Skew-T log-pSkew-T log-p diagram, Boise Airport, ID at 12:00Z on 2021-08-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 40 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Boise Airport, ID at 12:00Z on 2021-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -166 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
40 J/kg
Mixed-layer CIN
-373 J/kg
Mixed-layer LCL
2085 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-166 m²/s²
0-3 km storm-relative helicity
-19 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted.

702 
WWUS85 KMSO 062332
SPSMSO

Special Weather Statement
National Weather Service Missoula MT
532 PM MDT Fri Aug 6 2021
 
IDZ010-070015-
Eastern Lemhi County ID-
532 PM MDT Fri Aug 6 2021

...Strong thunderstorms will impact portions of central Lemhi County
through 615 PM MDT...

At 531 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 8 miles southeast of Gibbonsville to Salmon.
Movement was south at 10 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects.

Locations impacted include...
Salmon, Carmen, Williams Lake and Baker. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

These storms 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 4479 11398 4516 11397 4552 11380 4552 11377
      4548 11376 4545 11378 4543 11376 4541 11377
      4539 11373 4533 11374 4529 11368 4525 11369
      4519 11360 4516 11359 4512 11356
TIME...MOT...LOC 2331Z 356DEG 8KT 4547 11380 4518 11394 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

$$

The office that day

Everything else NWS Missoula, MT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 5, 6:21 PM MDTSpecial Weather StatementMSOPowell39 min
Aug 5, 8:08 PM MDTSpecial Weather StatementMSO52 min
Aug 5, 9:12 PM MDTSpecial Weather StatementMSO48 min
Aug 6, 1:13 AM MDTSpecial Weather StatementMSORavalli47 min
Aug 6, 2:46 PM MDTFire Weather WatchMSOBeaverhead, Deer Lodge, Granite, Jefferson, Madison, Powell and 1 more22 hr
Aug 5, 9:20 PM MDTSpecial Weather StatementMSOIdaho40 min
Aug 5, 9:24 PM MDTSpecial Weather StatementMSOClearwater36 min
Aug 5, 9:38 PM MDTSpecial Weather StatementMSOIdaho52 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.