Special Weather Statement, NWS North Platte, NE

Area Forecast Discussion
National Weather Service North Platte NE
1228 AM CDT Thu Aug 26 2021

.SHORT TERM...(This evening through Thursday night)
Issued at 338 PM CDT Wed Aug 25 2021

20z Vsby satellite this afternoon suggests a weak upper level
disturbance is operating across nern Colorado. This disturbance has
set off thunderstorms across swrn Nebraska. Satellite and KGLD VWP
suggest the storms are forming just above the stratus layer
associated with a sfc inversion a few thousand feet deep. Another
disturbance is shown on satellite across swrn UT which could affect
wrn and ncntl Nebraska late tonight. Timing tools suggest this
disturbance will affect wrn Nebraska by 08z tonight.

The basic thunderstorm forecast tonight revolves around the
development of a low level jet across KS which will lift a warm
front into swrn or wcntl Nebraska by morning. The POP forecast
follows the trusty SREF which has been performing better than the
HRRR. The HRRR was the best model earlier this week but fell behind
last night and this afternoon.

The very strong shear associated with the 25-35 kt low level jet and
a belt of 25-40kt westerlies at h500-300mb, PWAT 1.25-1.5 inches and
fairly steep lapse rates could support severe storms. A strong cap
at 800mb shown by the NAM and RAP models appears to holding back
storm development. Presumably, the cap will limit storm coverage to
isolated. Only the NAMnest suggests more than isolated severe storm
coverage but this model is a sfc based CAM and the convection
tonight will be mostly elevated forming north of a warm front.

This storm activity will probably be across SD or nrn Nebraska
Thursday morning. The sfc warm front should be near the SD border
with a large warm sector open across wrn and ncntl Nebraska. The NAM
will then sink a cold front into or toward swrn Nebraska during the
afternoon. The front, robust moisture, steep lapse rates and a model
predicted UA disturbance moving off the Colorado Rockies are the
basis for chance to likely POPs across wrn and ncntl Nebraska
beginning late Thursday afternoon and continuing overnight.

The best focus for severe weather Thursday might be across nrn
Nebraska where winds aloft increase to 40-50 kts at h500-300mb.
Weaker winds aloft across srn Nebraska will support more of a
locally heavy rain threat. The NAM suggests conditions would be
prime in both areas by 22z. Later in the evening and overnight,
temperatures aloft may warm due to diabatic heating from heavy rain.
The time of storm initiation will probably be dictated by upper
level support which is difficult to predict beyond 12hrs, especially
if it is associated a subtropical disturbance which tend to amplify
crossing the Rockies.

.LONG TERM...(Friday through Wednesday)
Issued at 338 PM CDT Wed Aug 25 2021

A dry forecast is in place Friday. A plume of deep moisture should
be south and east of wrn and ncntl Nebraska. The models continue
to draw this moisture back north and west Saturday. A fairly
strong upper level disturbance will move through the nrn Plains
and reach south into Nebraska. The best rain chance for this
system is currently advertised across ncntl Nebraska but moisture-
PWAT greater than 1.25 inches, will be available across swrn
Nebraska if the dynamics can reach farther south.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1228 AM CDT Thu Aug 26 2021

Thunderstorms off to the south and east of the KLBF terminal
should remain east of the area overnight, so thunderstorms are not
expected through sunrise. Low clouds have developed in the wake of
thunderstorms tonight off to the west of the KLBF terminal and
this cloudiness should move into the remainder of SW Nebraska
overnight. Ceilings at the KLBF terminal will eventually end up
below 1000 FT AGL toward daybreak with some visibility reductions
to around 3 SM. After mid morning skies will gradually clear with
some scattered high clouds possible Thursday afternoon/evening.
For the KVTN terminal, expect scattered high clouds overnight.
ATTM, low cloudiness should remain off to the south of the
terminal and not be an impact.

&&

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

SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Buttler

Hazardous Weather Outlook
National Weather Service North Platte NE
259 PM CDT Wed Aug 25 2021

NEZ004>010-022>029-035>038-056>059-069>071-094-262000-
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-
259 PM CDT Wed Aug 25 2021 /159 PM MDT Wed Aug 25 2021/

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

Isolated thunderstorms are expected to continue this afternoon
and into tonight across areas of western and north central
Nebraska. A few storms could be strong to severe, capable of
producing large hail, strong winds, and locally heavy rainfall.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

Scattered thunderstorms are possible Thursday afternoon and
evening. There is a slight risk for severe storms, mainly across
the northern Sandhills and north central Nebraska.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected today or tonight.

&&

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

Special Weather Statement
National Weather Service North Platte NE
1257 AM CDT Thu Aug 26 2021

NEZ027-038-260645-
Loup NE-Custer NE-
1257 AM CDT Thu Aug 26 2021

...A strong thunderstorm will impact portions of south central Loup
and northeastern Custer Counties through 145 AM CDT...

At 1256 AM CDT, Doppler radar was tracking a strong thunderstorm 7
miles southwest of Merna, or 9 miles west of Broken Bow, moving
northeast at 40 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

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

This includes the following highways...
 Highway 183 between mile markers 102 and 123.
 Highway 2 between mile markers 266 and 283.
 Highway 92 between mile markers 269 and 273.

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 4125 9983 4141 9998 4178 9936 4161 9921
      4154 9921
TIME...MOT...LOC 0556Z 235DEG 33KT 4139 9982

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Buttler

Special Weather Statement
National Weather Service North Platte NE
129 AM CDT Thu Aug 26 2021

NEZ038-260715-
Custer NE-
129 AM CDT Thu Aug 26 2021

...Strong thunderstorms will impact portions of eastern Custer County
through 215 AM CDT...

At 129 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Weissert to 8 miles south of Broken Bow to
6 miles southeast of Callaway. Movement was northeast at 35 mph.

HAZARD...Wind gusts up to 50 mph and nickel size 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...
Broken Bow, Sargent, Ansley, Mason City, Oconto, Comstock, Berwyn,
Weissert, Westerville, Round Valley, Arcadia Diversion Dam State
Wildlife Management Area, Burr Oak, Gavin Siding, Wescott,
Intersection of Highway 183 and Cumro Road, Buckeye, Block Hill
Basin, Pressey State Wildlife Management Area, Big Oak Canyon and
Cumro.

This includes the following highways...
 Highway 183 between mile markers 77 and 116.
 Highway 2 between mile markers 274 and 306.
 Highway 92 between mile markers 300 and 308.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

These storms 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 4111 9996 4130 9976 4156 9967 4172 9922
      4110 9921
TIME...MOT...LOC 0629Z 236DEG 32KT 4151 9954 4128 9965 4120 9986

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Buttler

Special Weather Statement
National Weather Service North Platte NE
209 AM CDT Thu Aug 26 2021

NEZ010-027>029-038-260800-
Wheeler NE-Loup NE-Holt NE-Custer NE-Garfield NE-
209 AM CDT Thu Aug 26 2021

...A strong thunderstorm will impact portions of southeastern Loup,
Garfield, southwestern Holt, northeastern Custer and southwestern
Wheeler Counties through 300 AM CDT...

At 208 AM CDT, Doppler radar was tracking a strong thunderstorm 5
miles southwest of Burwell, moving northeast at 35 mph.

HAZARD...Wind gusts up to 50 mph and nickel size 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...
Burwell, Deverre, Homestead Knolls Campground, Virginia Smith Dam,
Kent Diversion Dam State Wildlife Management Area and Gables.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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 4174 9884 4174 9921 4160 9921 4172 9937
      4210 9901 4184 9858
TIME...MOT...LOC 0708Z 225DEG 30KT 4171 9921

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Buttler