Alert archive / Nebraska / Special Weather Statements in 2018

Special Weather Statement, NWS North Platte, NE

July 18, 2018Loup County, Nebraska

NWS North Platte, NE issued this special weather statement at Jul 18, 2018, 8:41 PM CDT for Loup County, Nebraska. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 18, 2018, 8:41 PM CDT (01:41 UTC)
Expired: Jul 18, 2018, 9:30 PM CDT
In force: 49 min
Issued by: NWS North Platte, NE

County Loup County, NE

The radar

The North Platte radar (KLNX), 109 km from the middle of the area, began a volume at 01:41 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 1.7 hours before the alert went out and 126 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1653 J/kg
Mixed-layer CIN: -25 J/kg
Mixed-layer LCL: 1532 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 88 m²/s²
0-3 km storm-relative helicity: 117 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 5.8

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS North Platte, NE wrote its last area forecast discussion before this special weather statement went out at Jul 18, 6:50 PM CDT, 1 hour 51 minutes earlier.

Area forecast discussion, Jul 18, 6:50 PM CDT, 1 hour 51 minutes before

Area Forecast Discussion
National Weather Service North Platte NE
650 PM CDT Wed Jul 18 2018

.SYNOPSIS...
Issued at 249 PM CDT Wed Jul 18 2018

H5 analysis this morning had a tandem of shortwaves
across the central CONUS. The first over southern Nebraska and a
second over central South Dakota. Another shortwave was located over
western Oklahoma. High pressure remained anchored across the desert
southwest and this feature extended east into far western Texas.
Further east, a persistent trough of low pressure extended from
northern Quebec into New England. At the surface, a mid day analysis
had a surface low roughly over Phillip South Dakota. A weak wind
convergent line extended east southeast, then south into central
Nebraska, or roughly along a line from just east of Winner SD to
east of Broken Bow NE. Winds were southeasterly east of the
convergent line with westerly winds noted west of the line. AS of 2
PM CDT under partly cloudy skies, readings ranged from 80 to 85
degrees.

&&

.SHORT TERM...(This evening through Thursday)
Issued at 249 PM CDT Wed Jul 18 2018

The main forecast challenge lies
in the first 6 to 12 hours of the short term forecast. Already as of
1 PM CDT, an area of steepening low level lapse rates has spread
east along the SD/NEBR border. The nose of these higher lapse rates
was located INVOF Winner South Dakota as of 2 PM CDT per the SPC
meso page. Current satellite imagery has an area of "agitated" Cu
along the SD/NEBR border from Valentine east to Boyd County. This
area is colocated near the nose of the higher lapse rates and INVOF
a surface wind convergence boundary which extends from east of
Winner SD into north central and central Nebraska. ATTM,
thunderstorms are expected to initiate along the SD/NEBR border near
forecast issuance. Wouldn't be surprised if some initiation also
occurs further north possibly as far north as I90 in central SD.
Favorable deep layer shear and the presence of favorable elevated
CAPE, and steep mid level lapse rates, will favor large hail as the
main thunderstorm threat initially. Would expect the tornado threat
to be confined to the northeastern forecast area where the surface
winds are either east southeast or southeast-ie. location where low
level helicities are expected to be most favorable. As this activity
tracks southeast into north central, and central Nebraska this
evening, the severe threat is expected to shift from Hail/wind, to
more of a wind/heavy rain threat. ATTM the greatest threat for
thunderstorms/severe storms appears to reside in the 5 PM CDT to 11
PM CDT time frame, although, convection initiation is expected to
be earlier than that, more during the 3 PM CDT to 5 PM CDT time
frame. Thunderstorms are expected to exit shortly after midnight
with mainly clear skies expected behind the exiting tsras. Was
concerned initially about fog potential overnight, however, with no
support from numerical guidance, will forgo mentioning fog. Much
warmer air will begin to push into the western forecast area on
Thursday as ridging begins to build north and northeast into the
central Rockies/Central Plains. H85 temps by Thursday afternoon,
approach 30 to 32 degrees C in the far southwest. That being said,
fcst highs in the upper 90s remain on track.

.LONG TERM...(Thursday night through Wednesday)
Issued at 249 PM CDT Wed Jul 18 2018

Thursday night through Saturday...The upper level
disturbance, responsible for thunderstorms Tonight, will drift east
into Minnesota and Wisconsin Friday, ending up in Indiana by
Saturday. At the same time, ridging will build into the northern
Rockies then northern plains by Saturday. This will lead to a mainly
dry forecast with highs in the upper 80s to lower 90s.

Saturday night through Wednesday...Beginning Saturday night, a
trough of low pressure aloft will track across southern Canada. Mid
level warm air advection will increase Saturday night from
northeastern Colorado into western Nebraska. This will lead to an
increased threat for thunderstorms Saturday night in the west.
Better chances for showers and thunderstorms will arrive Sunday
night in association with a cold fropa. Low end precipitation
chances will continue into midweek next week. Upper level high
pressure will intensify and move west to the swrn CONUS early next
week. This will place the forecast area in northwesterly flow aloft
with weak upper level disturbances riding this flow from the
northern Rockies, se into the central plains.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 639 PM CDT Wed Jul 18 2018

Local radar display shows numerous storms across north central
NEB east of highway 83, some strong to severe. Current thinking is
storms will continue to affect mainly north central NEB through
the evening hours moving east to southeast. Otherwise, current
thinking is storms will not affect the KLBF terminal. Storms not
expected to affect directly the KVTN terminal but will be nearby
thus VCTS present through 03Z. Of which, gusty outflow winds could
affect the terminal but confidence low so tempo group at this
time. Chances for thunderstorms diminish late tonight with skies
clearing. Tomorrow, sunny skies and VFR conditions prevail with
light northwest breezes.

&&

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

SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...ET

Hazardous weather outlook, Jul 18, 3:40 PM CDT, 5 hours 1 minute before

Hazardous Weather Outlook
National Weather Service North Platte NE
340 PM CDT Wed Jul 18 2018

NEZ004>010-022>029-035>038-056>059-069>071-094-192045-
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-
340 PM CDT Wed Jul 18 2018 /240 PM MDT Wed Jul 18 2018/

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

.DAY ONE...TONIGHT.

Severe thunderstorms are likely this afternoon and evening north
of a line from Sparks to Burwell. Primary threats will be large
hail, strong winds, and isolated tornadoes. A tornado watch is in
effect until 11 PM CDT.

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

Additional thunderstorms are possible in the afternoon and evening
Sunday through Wednesday. Severe potential is uncertain at this
time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed this afternoon and
evening for locations northeast of a line from Sparks to Burwell.

&&

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

kulik

In the hours before

Special weather statement, Jul 18, 8:04 PM CDT, 37 minutes before

Special Weather Statement
National Weather Service North Platte NE
804 PM CDT WED JUL 18 2018

NEZ038-190145-
Custer NE-
804 PM CDT WED JUL 18 2018

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL CUSTER COUNTY UNTIL
845 PM CDT...

At 803 PM CDT, Doppler radar was tracking a strong thunderstorm
about 5 miles north of Ansley, or 16 miles east of Broken Bow,
moving southeast at 15 mph.

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

This storm will remain over mainly rural areas of east central Custer
County.

This includes the following highways...
 Highway 183 between mile markers 93 and 97.
 Highway 92 between mile markers 303 and 308.

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.

&&

A Severe Thunderstorm Watch remains in effect until 100 AM CDT for
central Nebraska.

LAT...LON 4134 9942 4143 9936 4138 9920 4120 9920
      4119 9921
TIME...MOT...LOC 0103Z 297DEG 11KT 4136 9932

Snively

Local storm report, Jul 18, 8:07 PM CDT, 34 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
807 PM CDT WED JUL 18 2018

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

0740 PM     TSTM WND GST     3 N TAYLOR              41.81N 99.38W
07/18/2018  M62 MPH          LOUP               NE   TRAINED SPOTTER

            DIME SIZE HAIL ALSO OBSERVED

&&

SNIVELY

Local storm report, Jul 18, 8:13 PM CDT, 28 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
813 PM CDT WED JUL 18 2018

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

0755 PM     HAIL             5 W BURWELL             41.78N 99.23W
07/18/2018  E1.00 INCH       LOUP               NE   PUBLIC

            ONLY A FEW QUARTER SIZE HAIL

&&

THORNE

Special weather statement, Jul 18, 8:19 PM CDT, 22 minutes before

Special Weather Statement
National Weather Service North Platte NE
819 PM CDT WED JUL 18 2018

NEZ009-010-027-028-190200-
Loup NE-Holt NE-Garfield NE-Rock NE-
819 PM CDT WED JUL 18 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN ROCK...NORTHEASTERN
LOUP...SOUTHWESTERN HOLT AND NORTHWESTERN GARFIELD COUNTIES UNTIL 900
PM CDT...

At 818 PM CDT, Doppler radar was tracking a strong thunderstorm 14
miles north of Calamus Reservoir State Recreation Area, or 21 miles
north of Burwell, moving southeast at 20 mph.

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

Locations impacted include...
Deverre, Valley View Flat Campground, Carson Lake and Hannamon Bayou
Campground.

A Severe Thunderstorm Watch remains in effect until 100 AM CDT for
north central Nebraska.

LAT...LON 4210 9942 4217 9917 4187 9887 4188 9932
TIME...MOT...LOC 0118Z 327DEG 18KT 4207 9924

Snively

Local storm report, Jul 18, 8:38 PM CDT, 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
838 PM CDT WED JUL 18 2018

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

0825 PM     HAIL             16 N ONEILL             42.69N 98.65W
07/18/2018  E1.00 INCH       HOLT               NE   PUBLIC

&&

THORNE

Special weather statement, Jul 18, 8:41 PM CDT, 0 minutes before

Special Weather Statement
National Weather Service North Platte NE
841 PM CDT WED JUL 18 2018

NEZ027-028-038-190230-
Loup NE-Custer NE-Garfield NE-
841 PM CDT WED JUL 18 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN LOUP AND
NORTHEASTERN CUSTER COUNTIES UNTIL 930 PM CDT...

At 841 PM CDT, Doppler radar was tracking a strong thunderstorm over
Taylor, moving southeast at 25 mph.

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

Locations impacted include...
Taylor, Sargent, Comstock, Big Oak Canyon, Divide Hill, Wescott and
Kent Diversion Dam State Wildlife Management Area.

This includes Highway 183 between mile markers 107 and 130.

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.

&&

A Severe Thunderstorm Watch remains in effect until 100 AM CDT for
central and north central Nebraska.

LAT...LON 4174 9921 4152 9921 4153 9951 4182 9951
      4188 9931 4174 9920
TIME...MOT...LOC 0141Z 332DEG 20KT 4176 9939

Snively

The office that day

Everything else NWS North Platte, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 18, 7:02 PM CDT	Special Weather Statement	LBF	Garfield	43 min
Jul 18, 7:06 PM CDT	Severe Thunderstorm Warning	LBF	Boyd, Holt	39 min
Jul 18, 7:12 PM CDT	Tornado Warning	LBF	Loup	48 min
Jul 18, 7:42 PM CDT	Severe Thunderstorm Warning	LBF	Custer	33 min
Jul 18, 7:53 PM CDT	Special Weather Statement	LBF	Holt	67 min
Jul 18, 7:54 PM CDT	Severe Thunderstorm Warning	LBF	Custer, Garfield, Loup	21 min
Jul 18, 8:04 PM CDT	Special Weather Statement	LBF	Sherman	41 min
Jul 18, 8:10 PM CDT	Severe Thunderstorm Warning	LBF	Holt	50 min
Jul 18, 8:19 PM CDT	Special Weather Statement	LBF	Garfield	41 min
Jul 18, 9:00 PM CDT	Severe Thunderstorm Warning	LBF	Holt	45 min
Jul 18, 10:15 PM CDT	Special Weather Statement	LBF	Holt	45 min
Jul 18, 10:52 PM CDT	Special Weather Statement	LBF	Holt	38 min
Jul 18, 11:05 PM CDT	Severe Thunderstorm Warning	LBF	Holt, Wheeler	25 min
Jul 18, 11:27 PM CDT	Special Weather Statement	LBF	Wheeler	33 min
Jul 19, 12:00 AM CDT	Special Weather Statement	LBF	Wheeler	30 min

Nearby

Special Weather Statements in Nebraska, 2018 Every special weather statement in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.