Alert archive / Idaho / Special Weather Statements in 2020

Special Weather Statement, NWS Pocatello, ID

June 30, 2020Jefferson County, Idaho

NWS Pocatello, ID issued this special weather statement at Jun 30, 2020, 5:21 PM MDT for Jefferson County, Idaho. It was in force for 39 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 30, 2020, 5:21 PM MDT (23:21 UTC)
Expired
Jun 30, 2020, 6:00 PM MDT
In force
39 min
Issued by
NWS Pocatello, ID

County Jefferson County, ID

The radar

The Pocatello radar (KSFX), 71 km from the middle of the area, began a volume at 23:23 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

Salt Lake City I, UT (KSLC), launched 12:00Z, 11.4 hours before the alert went out and 328 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, Salt Lake City I, UT at 12:00Z on 2020-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 54 joules per kilogram.LCLLFCEL10008507005003002001001 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, Salt Lake City I, UT at 12:00Z on 2020-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 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
54 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
971 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
200 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

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 Jun 30, 2:08 PM MDT, 3 hours 13 minutes earlier.

Area forecast discussion, Jun 30, 2:08 PM MDT, 3 hours 13 minutes before
Area Forecast Discussion
National Weather Service Pocatello ID
208 PM MDT Tue Jun 30 2020

.SHORT TERM...Tonight through Thursday.

Low pressure over Wyoming will continue to move eastward tonight.
We'll see showers and isolated thunderstorms gradually end from west
to east late this afternoon and tonight. Small hail remains possible
in stronger thunderstorms because of cold temperatures across the
region. Frost/freeze around the main agricultural areas remains
unlikely as models suggest lows tonight will hold in the 40s. On
Wednesday, a secondary low pressure system will sweep through
western Montana. This system is close enough to trigger a few
afternoon thunderstorms, mainly affecting the mountains and
highlands. A marginal risk of thunderstorms exists Wednesday
afternoon with hail and strong winds the main threats. Gusty non-
thunderstorm winds are likely Wednesday afternoon with a lake wind
advisory possibly necessary for the American Falls Reservoir. The
flow turns southwesterly Thursday with temps recovering to near
normal. The southwest flow will bring some moisture into the region
as well and isolated thunderstorms across the area remain possible.

13

.LONG TERM...Fri through next Tue night. High pressure attempts to
dominate the pattern for southern Idaho, but the northern half will
continue to see an afternoon and evening thunderstorm threat as
shortwaves flatten out the north end of the upper level ridge and
provide the trigger when the atmosphere is unstable. Occasionally,
there may be some southern highland thunderstorms and showers, but
rarely during this period. Fortunately spectators at any fireworks
displays on the holiday, the driest weather appears to be Sat night.
The amount of thunderstorm coverage is of a great debate among the
model suites, but it still tends to be the ID-MT border and the
northern half of the ID-WY border. Expect breezy afternoons and
evenings as well for ridges and the Snake River plain/eastern Magic
Valley. Temperatures should return to near and above normal, topping
out Sun with highs in the lower elevations approaching 90 deg F.
Messick

&&

.AVIATION...TSRA expected to make a return, especially to the
northern half of eastern Idaho, so KIDA and KDIJ most at risk. But
even here it barely gets to chance category. The surprising thing is
how much the boundary layer of the atmosphere is expected to dry
out, and this should preclude fog or stratus development.  Must say
though that if fog does develop, that it should be a surprise, and
it would be over quickly with the strong sunshine. Expecting gusty
wind again Wed afternoon as well as TSRA/SHRA same time. Messick

&&

.FIRE WEATHER...Here's hoping that the snow is done as temperatures
moderate and the low that brought all the moisture and cold re-
curves from heading southeast and shift motion to the northeast.
After midnight tonight should be a relatively quiet period, but
another trough moving through western Montana on Wed should bring
back showers and thunderstorms, mainly to the northern 2/3 of the
fire weather forecast area. Breezy afternoons continue, but
temperatures stay well below normal and so humidity remains high
even in the afternoon. Near normal temperatures are finally reached
Fri, with humidity lowering into the teens in the lower elevations.
Messick

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&

In the hours before

Special weather statement, Jun 30, 5:21 PM MDT, 0 minutes before
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  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 5:33 PM MDTSpecial Weather StatementPIHBingham42 min

Nearby

Special Weather Statements in Idaho, 2020Every special weather statement in 2020

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.