Hail in Nebraska, August 8, 2018

Area Forecast Discussion
National Weather Service Cheyenne WY
1100 PM MDT Tue Aug 7 2018

.UPDATE...
Issued at 1020 PM MDT Tue Aug 7 2018

The last of today's thunderstorms are quickly collapsing after
causing quite a raucous as the storms moved from southeast
Wyoming into the western Panhandle. After these storms dissipate,
the rest of the evening and overnight period should be quiet with
areas of dense fog expected where heavy rain occurred. The office
itself here in Cheyenne received 0.92 inches within a two hour
period! Light overnight winds and clearing skies will accompany
the overnight period.

&&

.SHORT TERM...(This evening through Thursday night)
Issued at 215 PM MDT Tue Aug 7 2018

Northwest flow aloft prevails between a Great Basin upper ridge
and upper trough over the mid/lower Missouri River Valley. A weak
shortwave was moving across southern WY. A dew point boundary
extended east-west between Cheyenne and Kimball. A few t-storms
formed along this boundary early this afternoon. Although SBCAPEs
are progged between 1000-1500 j/kg over far southeast WY and
southern NE Panhandle this afternoon, 0-6km shear profiles are
weaker compared to recent days. Hail to the size of nickels, brief
heavy rain and gusty winds will accompany the stronger convection
along the I-80 corridor from Cheyenne east to Sidney through
early this evening.

The upper ridge will remain nearly stationary over the Intermountain
West through the short term. This will favor a drier northwesterly
flow aloft. Another weak shortwave tracks southeast across southeast
WY Wednesday afternoon, which may trigger isolated t-storms from
the southern Laramie Range east to Kimball. Dry and warm weather
is forecast Thursday. Winds will generally be light, except variable
and gusty near convection. Temperatures will average around 5 degrees
above seasonal normals.

.LONG TERM...(Friday through Tuesday)
Issued at 200 PM MDT Tue Aug 7 2018

Friday/Saturday...Healthy ridging aloft will limit any thunderstorm
development, so kept these days dry. Slow warming trend into
Saturday.

Sunday...Perhaps some isolated late day thunderstorms associated
with a cold front progged to drift southward into our counties.

Monday/Tuesday...With the ridge breaking down a bit, and some
additional low and mid level moisture, we may see isolated afternoon
and evening thunderstorms develop. Continued seasonably mild.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1056 PM MDT Tue Aug 7 2018

HRRR hinting at some low stratus around Cheyenne in the morning.
Recent rain from this afternoon/evening has moistened lower
atmosphere, so there could be a good chance. Could see some fog at
KBFF also with southeast up-valley winds. VFR elsewhere.

&&

.FIRE WEATHER...
Issued at 200 PM MDT Tue Aug 7 2018

A few weak disturbances will produce widely scattered afternoon and
evening showers and thunderstorms over extreme southeast Wyoming and
the southern Nebraska Panhandle through Wednesday. Elsewhere, dry
conditions will prevail, with the lowest relative humidities between
7 and 15 percent over the lower elevations of Carbon County. Fire
weather concerns will be minimal due to non-critical wind speeds.
Seasonably warm and dry weather with light winds will dominate the
districts late this week into the weekend.

&&

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

UPDATE...AB
SHORT TERM...MAJ
LONG TERM...RUBIN
AVIATION...GCC
FIRE WEATHER...MAJ

Hazardous Weather Outlook
National Weather Service Cheyenne WY
643 AM MDT Tue Aug 7 2018

NEZ002-003-019>021-054-055-095-096-WYZ101>119-081245-
Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Kimball-Cheyenne-
North Sioux-South Sioux-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-
643 AM MDT Tue Aug 7 2018

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

.DAY ONE...TODAY AND TONIGHT

Patchy fog can be expected over the high plains of southeast
Wyoming and the western Nebraska Panhandle through 9 AM MDT this
morning. Visibilities may be reduced to one half mile at times.
Motorists are advised to use caution.

A few showers and thunderstorms are possible this afternoon and
evening, mainly along the Interstate 80 corridor between Laramie
and Sidney. Severe weather is not expected. However, a few storms
could produce small hail and gusty winds.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

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
339 AM MDT WED AUG 8 2018

NEZ020-054-055-081030-
Kimball NE-Cheyenne NE-Banner NE-
339 AM MDT WED AUG 8 2018

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN CHEYENNE...NORTHEASTERN
KIMBALL AND SOUTHEASTERN BANNER COUNTIES UNTIL 430 AM MDT...

At 339 AM MDT, Doppler radar was tracking a strong thunderstorm over
Dix, or near Kimball, moving east at 10 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Kimball, Potter and Dix.

This includes Interstate 80 in Nebraska between mile markers 22 and
42.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm 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 4116 10363 4144 10368 4143 10321 4106 10327
TIME...MOT...LOC 0939Z 271DEG 7KT 4125 10354

Hammer

Special Weather Statement
National Weather Service Cheyenne WY
427 AM MDT WED AUG 8 2018

NEZ020-054-081115-
Kimball NE-Banner NE-
427 AM MDT WED AUG 8 2018

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN KIMBALL AND SOUTHEASTERN
BANNER COUNTIES UNTIL 515 AM MDT...

At 427 AM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 7 miles southeast of Harrisburg to near Dix to
near Kimball Airport. Movement was southeast at 10 mph.

Nickel size hail will be possible with these storms, along with very
heavy rain.

Locations impacted include...
Kimball, Dix and Kimball Airport.

This includes Interstate 80 in Nebraska between mile markers 20 and
35.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4161 10339 4105 10338 4106 10368 4155 10368
TIME...MOT...LOC 1027Z 308DEG 8KT 4149 10361 4132 10350 4113 10360

Hammer