Special Weather Statement, NWS Cheyenne, WY

Area Forecast Discussion
National Weather Service Cheyenne WY
1139 AM MDT Sun May 29 2022

.SHORT TERM...(Today and Monday)
Issued at 346 AM MDT Sun May 29 2022

Mostly quiet across the CWA early this morning with some light
shower activity present in the high terrain and dry conditions for
the lower elevations. Current temperatures are in the 40s for areas
west of the Laramie Range and 50s for areas off to the east. Some
southern Nebraska panhandle sites are still in the 60s due to cloud
cover overhead.

Weather quickly turns active today as convection looks to initiate
early this afternoon. CAMs and other Hi-Res models show a broad
swath of thunderstorms moving across the eastern half of the
CWA by mid-afternoon/evening. A left jet exit region overhead favors
the development of some isolated strong to potentially severe
storms. Primary threats include both wind and hail, namely in the
Nebraska panhandle where the environment will be more favorable due
to more instability, shear, and moisture present. RAP13
thermodynamic profiles show inverted "V" soundings during the
afternoon hours with sufficiently steep low- to mid-level lapse
rates which could lead to strong, gusty and erratic winds in
thunderstorms. Profiles also show the potential for large hail as
there will be a good amount of moisture available for growth.
Thunderstorm activity will likely continue through the evening hours
but should diminish by midnight.

Models have come into better agreement on how Memorial Day will play
out. Models paint a pretty wet picture for the northern half of the
CWA. ECMWF is definitely the wettest of them all with the highest 6-
hr QPF amounts on Monday. ECMWF keeps the surface low closer to home
which gives most of the CWA some decent precipitation. Both the NAM
and GFS keep the low further off to the east, which may keep much of
the southern and western portion of the CWA dry during the
afternoon. Either way, Memorial Day looks like it will be damp and
cool as sub-0C 700 mb temperatures move in. Highs will max out in
the 50s for most places, with some low 60s expected for the southern
Nebraska panhandle. Although Memorial Day marks the unofficial start
of summer, it will still be cold enough in the mountains for the
Snowy and Sierra Madre Ranges to pick up a few inches of snow.

.LONG TERM...(Tuesday through Saturday)
Issued at 346 AM MDT Sun May 29 2022

Models and ensembles continue to show cooler than normal
temperatures through the middle of the week with nearly a daily
chance of showers and thunderstorms. However, models continue to
struggle with the secondary upper level disturbance as it ejects
east across the Front Range Tuesday night. During the day, expect
bands of rain showers and embedded thunder through most of the
day and into Tuesday evening with ample instability during the
day. Snowlevels will range between 7000 to 8500 feet so can't rule
out some snow across the high valleys, but confidence is limited
at this time with not a lot of cold air associated with the
main trough axis. Kept POP between 50 to 65 percent Tuesday
afternoon with some low level convergence and low to midlevel
instability present. It seems realistic that temperatures will
struggle to reach 50 degrees due to ample cloud cover and upslope
northeast winds, so started lowering highs on Tuesday with some
locations remaining in the 40s through the day. Considerable
uncertainty Tuesday night and Wednesday with the ECMWF, and to a
lesser degree the Canadian, showing the secondary upper level
disturbance ejecting eastward slowly producing another larger area
of moderate to heavy rainfall with snowfall down to 7000 feet. The
ECMWF in particular shows another inch of QPF as this disturbance
slowly moves across Wyoming and Colorado. In contrast, the GFS
shows a much weaker disturbance that dissipates as it moves into
the High Plains with much drier conditions on Wednesday.
Ensembles show a wide spread in POP and QPF during this time
period also, so decided to lower forecast POP below NBM blends at
this time. Wednesday will be a little milder, but highs will
likely not reach 60 degrees for most locations.

As we head towards late next week, models all show a broad upper
level ridge axis amplifying over the western United States and
drifting east into the Front Range by Thursday. However, models
are not indicating a stalled cold front remaining near the Laramie
Range with it's position fluctuating between the mountains and
portions of the High Plains each day. Expect Thursday to be the
driest day of the week with highs climbing into the 60s to low
70s. Started increasing POP for Friday and next Saturday with
models showing a good potential at some strong to possibly severe
thunderstorms. Lowered high temperatures a few degrees as we head
into next weekend with a more unsettled pattern compared to 24 to
48 hours ago.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1130 AM MDT Sun May 29 2022

Currently VFR conditions as mid- to high-clouds and
showers/thunderstorms begin to move into southeast Wyoming. The
showers and thunderstorms will continue to become more widespread
through the afternoon causing brief reductions in cigs and
visibilities. There is a chance for IFR to LIFR conditions at KCDR
and KAIA where the winds should reduce by mid-morning and low cigs
and fog could hang around until the winds pick up mid-morning.

&&

.FIRE WEATHER...
Issued at 346 AM MDT Sun May 29 2022

Minimal fire weather concerns expected through mid-week. Widespread
precipitation and cooler temperatures over the next several days
should keep minimum RHs well above 20 percent for most areas.
Thunderstorms are likely Sunday afternoon. Expect gusty and erratic
winds in these storms. Widespread rainfall and mountain snow are
possible Monday through Tuesday.

&&

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

SHORT TERM...SF
LONG TERM...TJT
AVIATION...LK
FIRE WEATHER...SF

Hazardous Weather Outlook
National Weather Service Cheyenne WY
1030 AM MDT Sun May 29 2022

WYZ101>119-301630-
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-
1030 AM MDT Sun May 29 2022

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

.DAY ONE...TODAY AND TONIGHT

Scattered thunderstorms will develop around midday and move to
the northeast across the area through this evening. Some of the
thunderstorms may produce wind gusts 60 mph or higher and pea to
penny size hail.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

Showers and widely scattered thunderstorms are forecast Memorial
Day through Wednesday. Light snow accumulations are expected for
elevations above 8000 feet.

.Spotter information statement...

Spotter activation will not be required through tonight.

NEZ002-003-019>021-054-055-095-096-301630-
Dawes County-Box Butte County-Scotts Bluff County-Banner County-
Morrill County-Kimball County-Cheyenne County-
Northern Sioux County-Southern Sioux County-
1030 AM MDT Sun May 29 2022

This hazardous weather outlook is for the western Nebraska
Panhandle.

.DAY ONE...TODAY AND TONIGHT

Scattered thunderstorms will develop this afternoon and move to
the northeast across the area through this evening. Some of
the thunderstorms may produce wind gusts 60 mph or higher and
penny to quarter size hail.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

Showers and widely scattered thunderstorms are forecast Memorial
Day through Wednesday.

.Spotter information statement...

Spotter activation will not be required through tonight.

<!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>

<!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>

Special Weather Statement
National Weather Service Cheyenne WY
212 PM MDT Sun May 29 2022

NEZ019-020-WYZ107-108-118-292045-
Scotts Bluff NE-Banner NE-East Platte County WY-Goshen County WY-
Central Laramie County WY-
212 PM MDT Sun May 29 2022

...A strong thunderstorm will impact portions of southwestern Scotts
Bluff, northwestern Banner, southern Goshen, northeastern Laramie and
southeastern Platte Counties through 245 PM MDT...

At 211 PM MDT, Doppler radar was tracking a strong thunderstorm 8
miles southwest of Hawk Springs, or 26 miles southwest of Torrington,
moving northeast at 50 mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Lingle, La Grange, Yoder, Huntley, Hawk Springs Campground, Hawk
Springs Recreation Area, Veteran and Hawk Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4156 10447 4176 10466 4215 10436 4171 10389
      4166 10404
TIME...MOT...LOC 2011Z 223DEG 45KT 4173 10441

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH

Dewey