Special Weather Statement, NWS Cheyenne, WY

Area Forecast Discussion
National Weather Service Cheyenne WY
237 PM MDT Wed Jul 21 2021

.SHORT TERM...(This evening through Thursday)
Issued at 153 PM MDT Wed Jul 21 2021

Latest KCYS radar scanning pockets of isolated to scattered
showers and thunderstorms this afternoon as precipitable water
remains from about half an inch to just above an inch for storms.
Some better storm motions on the WY side to keep showers moving
as our region taps into some monsoonal moisture. Main threat out
of the strongest storms this afternoon expected to be heavy
rainfall though small hail and gusty winds may be a possibility.
High res models continue the main brunt of shower activity of the
Mullen burn scar this afternoon to alleviate immediate concerns
on debris flows and flooding.

Overnight lows dropping into the middle 50s to low 60s west of the
Laramie Range and from the upper 50s to middle 60s eastward.

Thursday continues the trend of high pressure ridging as pockets
of vorticity advection moves across the western portion of the
forecast area bringing about another afternoon and evening chances
of showers and thunderstorms. Highs Thursday will again be on the
above-normal side and a few degrees high from today with upper 90s
and low 100s in the NE Panhandle and upper 80s to upper 90s across
southeastern WY.

.LONG TERM...(Thursday night through Wednesday)
Issued at 153 PM MDT Wed Jul 21 2021

Canadian High Plains low pressure system with accompanied cold
front will drape through the region Friday morning but model
trends have lifted the boundary a touch further north as was
mentioned in previous forecast limiting the extent and relief of
some cooler temperatures across the region. Temperatures going
into the weekend will be a few degrees cooler with highs still
into the upper 80s and low 90s. With the frontal influence coupled
with the lingering high pressure, monsoonal moisture tap remains
flowing increase our precipitable water amounts into the region
with better western forcing to keep focus on the Mullen Burn Scar
as overall shear values fairly lacking for decent motion to
alleviate flooding concerns so will have to monitor trends for
flooding possibilities.

High pressure ridge through the weekend stays fairly dominate
across the US Southwest with a few upper level troughs moving
through with moisture for continued near daily chances of
precipitation activity.

Near the end of the period, some movement eastward and breakdown
of the ridge as a Pacific low encroaches on the California
coastline late Tuesday into Wednesday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1116 AM MDT Wed Jul 21 2021

VFR conditions prevail at all TAF sites with SCT to BKN mid- to
high- clouds moving across southeast Wyoming and western Nebraska
along with some brief rain showers. VCTS expected at KCYS, KLAR,
KBFF, KSNY, and KAIA between 21Z and 3Z, and at KCDR between 1Z
and 6Z. If a thunderstorm happens to move over a TAF site, it may
briefly lower the visibility and increase the winds.

&&

.FIRE WEATHER...
Issued at 214 PM MDT Wed Jul 21 2021

Limited fire weather concerns over the next several days as
monsoonal moisture brings near daily chances of isolated to
scattered showers and thunderstorms. Above-normal temperatures
will remain steady as min RHs remain from the upper teens into the
middle 20s and as winds generally remain below criteria albeit
outside of thunderstorm influence. Dry lightning may be a concern
for some locations with thunderstorm chances.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&

SHORT TERM...WM
LONG TERM...WM
AVIATION...LK
FIRE WEATHER...WM

Hazardous Weather Outlook
National Weather Service Cheyenne WY
518 AM MDT Wed Jul 21 2021

WYZ101>119-221130-
Converse County Lower Elevations-Niobrara County-
North Laramie Range-Ferris/Seminoe/Shirley Mountains-
Shirley Basin-Central Laramie Range and Southwest Platte County-
East Platte County-Goshen County-Central Carbon County-
North Snowy Range Foothills-Southwest Carbon County-
Sierra Madre Range-Upper North Platte River Basin-Snowy Range-
Laramie Valley-South Laramie Range-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
518 AM MDT Wed Jul 21 2021

This hazardous weather outlook is for portions of east central
Wyoming...south central Wyoming and southeast Wyoming.

.DAY ONE...TODAY AND TONIGHT

Scattered showers and thunderstorms this afternoon with heavy
rainfall possible, mainly near the Colorado border. Slow moving storms
with heavy rainfall could lead to flash flooding, especially in
recently burn areas.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

The probability for widespread hazardous weather is low.

.Spotter information statement...

Spotter activation will not be needed.

NEZ002-003-019>021-054-055-095-096-221130-
Dawes County-Box Butte County-Scotts Bluff County-Banner County-
Morrill County-Kimball County-Cheyenne County-
Northern Sioux County-Southern Sioux County-
518 AM MDT Wed Jul 21 2021

This hazardous weather outlook is for portions of panhandle
Nebraska.

.DAY ONE...TODAY AND TONIGHT

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

The probability for widespread hazardous weather is low.

.Spotter information statement...

Spotter activation will not be needed.

Special Weather Statement
National Weather Service Cheyenne WY
342 PM MDT Wed Jul 21 2021

NEZ002-212215-
Dawes NE-
342 PM MDT Wed Jul 21 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN DAWES COUNTY UNTIL
415 PM MDT...

At 341 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles northeast of Chadron, moving east at 25 mph.

Penny size hail and wind gusts up to 50 mph will be possible with
this storm.

This storm will remain over mainly rural areas of northeastern Dawes
County.

LAT...LON 4289 10299 4296 10296 4294 10279 4280 10279
      4280 10280
TIME...MOT...LOC 2141Z 290DEG 22KT 4289 10288

Rubin

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <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.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <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.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>