Special Weather Statement, NWS North Platte, NE

Area Forecast Discussion
National Weather Service North Platte NE
626 PM CDT Tue Jun 19 2018

.SHORT TERM...(This evening through Wednesday)
Issued at 230 PM CDT Tue Jun 19 2018

Latest water vapor loop shows an broad mid-level low over the
Northern Rockies and Northern High Plains with a strong shortwave
trough tracking from north central CO into western NEB. Latest
satellite imagery shows largely stratocu, broken-overcast, across
much of the forecast area with coverage more so scattered across
parts of southwest NEB. Meanwhile, numerous strong to severe
thunderstorms have developed over the last two and half hours
across southeast WY-northeast CO per regional radar display.
Elsewhere, weak thunderstorms with infrequent lightning are noted
in the far northeast Panhandle that are tapering off. Mesoanalysis
shows a surface low over southeast CO with a stationary front
extending from southwest KS to northeast NEB.

Storms that have developed upstream in the higher terrain, wherein
moist upslope flow is present and there is supportive broad
forcing for ascent in an area of moderate instability, are
expected to continue to evolve and track into the eastern
Panhandle and far southwest late afternoon but more likely in the
early evening time frame. Some uncertainty regarding severity in
western and north central NEB, however, isolated strong-severe
thunderstorms are possible given parameter space featuring modest
mid-level lapse rates and deep layer vertical shear of about 40
kts in southwest NEB/southeast Panhandle. The primary threats are
damaging winds, large hail, and heavy rainfall. Current thinking
is will see convective evolution to cluster(s)/MCS that will
affect parts of western NEB early tonight. Thereafter storms will
evolve and track into/across north central NEB late tonight/small
hours. Threat for severe storms should be low late evening on.
Concerns will shift more so to heavy rain/minor flooding
potential. That said, any convection will need to be monitored
with heavy downpours with efficient rain production. Overall,
little change from the previous forecast with respect to heavy
rainfall. There will be ample moisture with precipitable water
values near to exceeding 150% of normal and warm cloud layer about
3000-3600 m AGL. Further, storm motion will be more favorable for
heavier rain amounts across north central NEB with slower storm
motion of 10-20 kts forecast there. Nonetheless the risk for
flash flooding in general appears low based on location of forcing
that is more south, forecast flash flood guidance, so-so storm
motion, and latest hi-res guidance. Nonetheless some localized
heavy rain/minor flooding cannot be ruled out tonight.

Tomorrow, cloudy and cool conditions will prevail with highs 8-18
degrees below seasonable normals. Upper-level low will shift move
to the Dakotas/NEB with chances for showers and embedded/isolated
thunder Wednesday. Best chances for precipitation will be across
northern and north central NEB.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 230 PM CDT Tue Jun 19 2018

Large scale pattern will feature an upper-level ridge that will be
building over the northern and central Rockies through Thursday.
Decreasing rain chances Wednesday night-Thursday with the best
chances across north central NEB in the time frame. Largely dry
conditions expected elsewhere across western NEB. Thereafter a
short break in precip chances as the aforementioned ridge moves
across NEB early Friday and breaks down. Unsettled conditions then
expected Friday night and this weekend. Wherein another shortwave
trough is expected to track from the northern High Plains into
eastern SD and northern NEB by Friday night. Thereafter pattern
remains largely unsettled with multiple disturbances noted in the
large scale pattern. Highs are expected to remain slightly below-
normal through Monday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 625 PM CDT Tue Jun 19 2018

Main aviation concerns overnight will be the development of
thunderstorms to move east across western Nebraska, potentially
impacting the KLBF and KVTN terminals between 02z and 08z. Models
differ on the track and coverage of the thunderstorms, so impacts
remain low at this time. MVFR ceilings at KVTN are expected to
lower to IFR from 09z-15z, then near or above 1000 ft agl into
Wednesday afternoon, along with scattered showers. At KLBF, VFR
ceilings should prevail until 09z, then mainly MVFR 09z-15z, then
improving to VFR.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&

SHORT TERM...ET
LONG TERM...ET
AVIATION...Roberg

Hazardous Weather Outlook
National Weather Service North Platte NE
306 PM CDT Tue Jun 19 2018

NEZ004>010-022>029-035>038-056>059-069>071-094-202015-
Sheridan-Eastern Cherry-Keya Paha-Boyd-Brown-Rock-Holt-Garden-
Grant-Hooker-Thomas-Blaine-Loup-Garfield-Wheeler-Arthur-McPherson-
Logan-Custer-Deuel-Keith-Perkins-Lincoln-Chase-Hayes-Frontier-
Western Cherry-
306 PM CDT Tue Jun 19 2018 /206 PM MDT Tue Jun 19 2018/

This Hazardous Weather Outlook is for portions of western and
north central Nebraska.

.DAY ONE...TONIGHT.

Showers and thunderstorms are expected late this afternoon and
tonight. The area of concern is western Nebraska late afternoon,
but then a convective complex will develop and build east. Areas
of locally heavy rainfall are possible across the entire forecast
area. There is the possibility of a severe storm or two late this
afternoon and tonight. The severe threat should remain confined
to southwest into southern Nebraska for the most part where large
hail and damaging wind will be possible.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

Thunderstorms with locally heavy rainfall will remain possible
Wednesday into Wednesday night.

Additional thunderstorms will again be possible this weekend, as
another storm system moves into the area.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will probably not be needed today or tonight.

&&

Get your weather, hydrological, and climate information at
http://www.weather.gov/northplatte

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
305 PM CDT TUE JUN 19 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0350 PM     TORNADO          6 NNW BRULE             41.18N 101.93W
06/17/2018                   KEITH              NE   TRAINED SPOTTER

            DELAYED REPORT...BRIEF TOUCHDOWN. NO DAMAGE.

&&

JWS

Special Weather Statement
National Weather Service North Platte NE
428 PM CDT TUE JUN 19 2018

NEZ071-192215-
Frontier NE-
428 PM CDT TUE JUN 19 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN FRONTIER COUNTY
UNTIL 515 PM CDT...

At 428 PM CDT, Doppler radar was tracking a strong thunderstorm near
Bartley, or 17 miles northeast of McCook, moving northeast at 20 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Medicine Creek Reservoir State Recreation Area, Orafino and Freedom.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4040 10054 4059 10017 4044 10002 4043 10009
      4036 10009 4035 10014 4035 10049
TIME...MOT...LOC 2128Z 240DEG 17KT 4033 10034

Jacobs

Special Weather Statement
National Weather Service North Platte NE
647 PM CDT TUE JUN 19 2018

NEZ069-070-200030-
Chase NE-Hayes NE-
647 PM CDT TUE JUN 19 2018

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN CHASE AND SOUTHWESTERN
HAYES COUNTIES UNTIL 730 PM CDT/630 PM MDT/...

At 647 PM CDT/547 PM MDT/, Doppler radar was tracking a strong
thunderstorm near Wauneta, or 15 miles southwest of Hayes Center,
moving northeast at 10 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Wauneta, Enders, Enders Reservoir State Recreation Area, Hamlet, Area
A Campground and Center Dam Campground.

This includes Highway 61 between mile markers 25 and 30.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 4035 10152 4037 10160 4069 10146 4044 10091
      4034 10115
TIME...MOT...LOC 2347Z 230DEG 10KT 4041 10129

Jacobs

Special Weather Statement
National Weather Service North Platte NE
745 PM CDT TUE JUN 19 2018

NEZ070-071-200130-
Frontier NE-Hayes NE-
745 PM CDT TUE JUN 19 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN FRONTIER AND
SOUTHEASTERN HAYES COUNTIES UNTIL 830 PM CDT...

At 744 PM CDT, Doppler radar was tracking a strong thunderstorm 11
miles southeast of Hayes Center, moving east at 35 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Quick, Bluegill Haven Campground, Willow View Campground and Red
Willow Reservoir State Recreation Area.

This includes Highway 83 between mile markers 27 and 37.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm. Do not drive
your vehicle through flooded roadways.

&&

LAT...LON 4048 10100 4054 10043 4035 10043 4035 10102
TIME...MOT...LOC 0044Z 260DEG 32KT 4041 10084

Snively