Alert archive / Idaho / Special Weather Statements in 2021

Special Weather Statement, NWS Pocatello, ID

July 13, 2021Fremont County, Idaho

NWS Pocatello, ID issued this special weather statement at Jul 13, 2021, 5:48 PM MDT for Fremont County, Idaho. It was in force for 42 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 13, 2021, 5:48 PM MDT (23:48 UTC)
Expired
Jul 13, 2021, 6:30 PM MDT
In force
42 min
Issued by
NWS Pocatello, ID

County Fremont County, ID

The radar

The Pocatello radar (KSFX), 160 km from the middle of the area, began a volume at 23:51 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

Great_falls, MT (KTFX), launched 12:00Z, 11.8 hours before the alert went out and 377 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, Great_falls, MT at 12:00Z on 2021-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 12:00Z on 2021-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2571 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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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 13, 1:34 PM MDT, 4 hours 14 minutes earlier.

Area forecast discussion, Jul 13, 1:34 PM MDT, 4 hours 14 minutes before
Area Forecast Discussion
National Weather Service Pocatello ID
134 PM MDT Tue Jul 13 2021

.SHORT TERM...Tonight through Thursday night. Water vapor imagery
this afternoon shows a dry upper trough extending from NW MT into
central Idaho. Winds this afternoon are a bit gusty, and should
continue to be so through this evening. Winds are strong enough to
warrant a Lake Wind Advisory for American Falls Reservoir. This
could be enough to trigger some modest thunderstorms over the Island
Park area this evening. Those storms should subside after sunset and
the passage of the upper trough, while surface winds begin to turn
down-valley overnight tonight. Lighter winds are in the forecast
tomorrow along with some cooler temperatures. As we head into
Thursday, models start picking up a weak shortwave coming in with
just enough moisture to trigger some isolated thunderstorms--mainly
across the Central Mountains and the Southeastern Highlands.
Hinsberger

.LONG TERM...Friday through next Tuesday. The models continue to
show a low pressure system anchoring in off the Canadian coast
Friday with the downstream ridge axis briefly shifting into WRN
Wyoming as an ejecting short-wave disturbance lifts NE through
Washington resulting in a slightly enhanced wind flow across the
CNTRL mountains and Snake Plain Friday afternoon. The low gradually
retrogrades westward and merges with a second incoming Pacific
disturbance further off the NW coast Saturday into Sunday with
amplification occurring Monday. This will allow and encourage the
ridge to expand westward across SE Idaho and intensify once again
resulting in hotter temperatures and possible Heat
Warnings/Advisories for portions of the Eastern Magic Valley, Snake
Plain, and southern mountains Sunday through Tuesday. The models are
also advertising monsoon moisture rotating north around the
periphery of the high into CNTRL Idaho Monday and/or Tuesday. Huston
&&

.AVIATION...A short-wave trough was shifting east through WRN
Montana early this afternoon. Convective allowing models suggest
that we could see an extension of thunderstorm activity southward
into DIJ through early this evening. Otherwise breezy WSW winds will
transport smoke from upstream fires into the region with partial VIS
restrictions possible in some areas (BYI and SUN). Winds decouple
after sunset with mostly VFR conditions outside of areas with smoke.
Huston
&&

.FIRE WEATHER...A weak, dry upper trough is working its way through
the Central Mountains this afternoon. This is the basis of our Red
Flag Warning this afternoon/evening for zones 410, 413, 425, and
427. The southern half of zone 422 will see some marginal
windspeeds, but also a persistent Haines of 6--so that zone is also
included in our current Red Flag Warning. The trough will move off
to the east tonight. Coverage of Haines 6 decreases overnight and
expands again tomorrow. Lighter winds are expected across the region
tomorrow as the weather regime remains hot and dry. Thursday gets a
little more interesting with the addition of some isolated
thunderstorms over the Central Mountains and Southeastern Highlands.
Coupled with a Haines of 6, we could see another round of critical
fire weather conditions on Thursday. Hot and dry weather remains in
the forecast through the weekend, but there are some signs we'll see
some moisture from the Southwest Monsoon make its way into the
region by next Tuesday. Hinsberger
&&

.AIR STAGNATION...
The accumulation of smoke from distant fires in NE California, SRN
Oregon, and SE Washington as well as fires in the CNTRL Idaho
mountains may produce moderate to unhealthy air quality conditions
across portions of SE Idaho as the flow aloft continues to advect
smoke from these fires east into our area. Huston
&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning continues until 10 PM MDT this evening for IDZ410-
413-422-425-427.

Lake Wind Advisory continues until 9 PM MDT this evening for IDZ054.
&&

In the hours before

Special weather statement, Jul 13, 5:48 PM MDT, 0 minutes before
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      <h1 id="headline">This service is currently unavailable.</h1>
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        Please try again in a few minutes.
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The office that day

Everything else NWS Pocatello, ID issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 13, 1:05 AM MDTRed Flag WarningPIHBannock, Bear Lake, Bingham, Blaine, Boise, Bonneville and 16 more21 hr
Jul 13, 2:15 AM MDTLake Wind AdvisoryPIHBannock, Bingham, Power19 hr
Jul 13, 5:56 PM MDTSevere Thunderstorm WarningPIHFremont, Teton28 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.