Alert archive / Nebraska / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 57, NWS North Platte, NE

April 21, 2007Cherry County, Nebraska

NWS North Platte, NE issued this severe thunderstorm warning at Apr 21, 2007, 5:00 PM MDT for Cherry County, Nebraska. It was in force for 60 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: Apr 21, 2007, 5:00 PM MDT (23:00 UTC)
Expired: Apr 21, 2007, 6:00 PM MDT
In force: 60 min
Issued by: NWS North Platte, NE
Area: Counties, with a storm outline in the text

County Cherry County, NE

The radar

The North Platte radar (KLNX), 84 km from the middle of the area, began a volume at 23:02 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 21, 12:57 PM MDT	Tornado Watch	SPC	9 hr

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 11.0 hours before the alert went out and 175 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: 58 J/kg
Mixed-layer CIN: -409 J/kg
Mixed-layer LCL: 1516 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 284 m²/s²
0-3 km storm-relative helicity: 277 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS53 KLBF 212300
SVRLBF
NEC031-220000-
/O.NEW.KLBF.SV.W.0057.070421T2300Z-070422T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NORTH PLATTE NE
600 PM CDT SAT APR 21 2007

THE NATIONAL WEATHER SERVICE IN NORTH PLATTE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN CHERRY COUNTY IN NORTH CENTRAL NEBRASKA...
  THIS INCLUDES THE CITY OF VALENTINE...

* UNTIL 700 PM CDT

* AT 557 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING GOLF BALL SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 11
  MILES EAST OF VALENTINE NATIONAL WILDLIFE REFUGE...OR ABOUT 24
  MILES SOUTH OF VALENTINE...AND MOVING NORTH AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SMITH FALLS STATE PARK BY 630 PM CDT...
  SPARKS BY 635 PM CDT...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. IF A TORNADO
IS SPOTTED... ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM.
WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A
TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A
STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

LAT...LON 4245 10067 4248 10020 4276 10018 4276 10021
      4300 10020 4299 10057

$$

MASEK

2 follow-up statements

000 
WWUS53 KLBF 212316
SVSLBF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
616 PM CDT SAT APR 21 2007

NEC031-220000-
/O.CON.KLBF.SV.W.0057.000000T0000Z-070422T0000Z/
CHERRY NE-
616 PM CDT SAT APR 21 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM CDT
FOR NORTHEASTERN CHERRY COUNTY...

AT 612 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING GOLF BALL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR WOOD LAKE...OR ABOUT 20 MILES SOUTHEAST OF VALENTINE...
MOVING NORTH AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  6 MILES EAST OF SMITH FALLS STATE PARK BY 635 PM CDT...
  SPARKS BY 640 PM CDT...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. IF A TORNADO
IS SPOTTED... ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM.
WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A
TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A
STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

LAT...LON 4245 10067 4248 10020 4276 10018 4276 10021
      4300 10020 4299 10057

$$

MASEK

000 
WWUS53 KLBF 212356
SVSLBF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
654 PM CDT SAT APR 21 2007

NEC031-220004-
/O.EXP.KLBF.SV.W.0057.000000T0000Z-070422T0000Z/
CHERRY NE-
654 PM CDT SAT APR 21 2007

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CHERRY COUNTY
EXPIRES AT 700 PM CDT...

THE THUNDERSTORMS HAVE WEAKEN BELOW SEVERE LIMITS...HOWEVER 
ADDITIONAL SEVERE THUNDERSTORMS ARE POSSIBLE TONIGHT. 
A TORNADO WATCH REMAINS IN EFFECT.

LAT...LON 4245 10067 4248 10020 4276 10018 4276 10021
      4300 10020 4299 10057

$$

MASEK

What forecasters said that day

The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at Apr 21, 1:44 PM MDT, 3 hours 16 minutes earlier.

Area forecast discussion, Apr 21, 1:44 PM MDT, 3 hours 16 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
244 PM CDT SAT APR 21 2007

...FORECAST CONCERNS 3 STORM SYSTEMS DAYS 1 THROUGH 7...

.DISCUSSION...
STORM NUMBER ONE...TONIGHT THROUGH SUNDAY...INCIPIENT STAGES OF
SEVERE WEATHER INCLUDING TORNADOES UNDERWAY HERE. STRONG SHEAR...
BALANCED BY ADEQUATE CAPE AND A STRONG CAP WHICH IS FCST TO WEAKEN
ABRUPTLY THIS AFTERNOON AS A PORTION OF THE UPPER LEVEL LOW EJECTS
ACROSS THE WRN HIGH PLAINS. TORNADO THREAT IS THE MAIN HIGHLIGHT WITH
THE FIRST PERIOD FCST. FLOODING IS ALSO A DEFINITE CONCERN AS IS VERY
LARGE HAIL. MAY BE ABLE TO RETOUCH THE GRIDS AND ADD VERY HEAVY
RAINFALL FOR THE FIRST PERIOD IF WE DONT GET INTO A WARNING SITUATION
TOO QUICKLY. QPF IS A 50 50 BLEND OF THE NAM12 AND GFS.

STORM NUMBER TWO...MONDAY NIGHT THROUGH WEDNESDAY AM....A BRIEF
REPRIEVE SUNDAY EVENING AND MONDAY BUT THEN BOTH THE ECMWF AND GFS
ARE FAIRLY CLOSE SWINGING ANOTHER H5 LOW THROUGH KS TUESDAY AND
WEDNESDAY.  THE H850 FRONT WILL LIFT NORTH TO NEAR THE NEBRASKA
BORDER MONDAY NIGHT AND TUESDAY MORNING WITH WRAP AROUND RAIN
DEVELOPING THEREAFTER. HEAVY RAINFALL APPEARS LIKELY AS THE UPPER
LEVEL LOW MOVES VERY SLOWLY. SEVERE WEATHER IS POSSIBLE LATE MONDAY
NIGHT AS THE H85 FRONT TRIES TO LIFT NORTH. MOISTURE IS ABUNDANT.
THE GFS POPS WERE USED BUT LIMITED TO 60 PERCENT. QPF IS GFS LIMITED
TO 0.25 INCHES PER 6 HOUR PERIOD. LATER FCSTS MAY HAVE TO ENTERTAIN A
FLASH FLOOD WATCH IF FCST RAINFALL CONTINUES TO EXCEED GUIDANCE.

STORM NUMBER THREE...FRIDAY NIGHT AND SATURDAY...SHORT WAVE RIDGING
TAKES HOLD WEDNESDAY NIGHT...THURSDAY AND EARLY FRIDAY BUT ANOTHER
VIGOROUS STORM SYSTEM COULD TRACK THROUGH THE CENTRAL PLAINS LATE
NEXT WEEK. TIMING AND LOCATION VARY SOMEWHAT BETWEEN THE FASTER GFS
AND SLOWER ECMWF BUT BOTH MODELS ADVERTISE YET ANOTHER POWERFUL STORM
SYSTEM. THE SLOWER ECMWF SOLN IS PREFERRED. AN H5 UA LOW IS FCST BY
BOTH MODELS TO MOVE THROUGH THE SWRN U.S. AND THEN THROUGH KS. THE
ECMWF IS ABOUT 24 HOURS SLOWER THAN THE GFS. A 30 TSTM POP HAS BEEN
INTRODUCED FOR FRIDAY NIGHT AND SATURDAY. THIS MATCHES THE TIMING OF
THE SLOWER ECMWF.

TEMPS...USED A BLEND OF NAM12 2M TEMPS AND GUIDANCE DAYS 1 THROUGH
3. THEREAFTER DAYS 4 THROUGH 7...HPC WAS USED.

&&

.AVIATION...
STRONG TO SEVERE CONVECTION WILL BE PRESENT ACROSS MUCH OF THE TWEB
ROUTES FROM THE LATE AFTERNOON INTO THE MID EVENING HOURS. CEILINGS
OUTSIDE OF THE THUNDERSTORMS SHOULD REMAIN AT VFR LEVELS...HOWEVER
IFR TO LIFR CONDITIONS MAY BE POSSIBLE IN THE STRONGEST CELLS AND
VSBYS WILL BE REDUCED TO BELOW A MILE AT TIMES DUE TO HEAVY RAINFALL
AND POSSIBLE HAIL. WINDS IN AND AROUND THESE STORMS WILL BE
DANGEROUS TO NAVIGATE THROUGH AND SHOULD BE AVOIDED. AS THE MAIN
SYSTEM MOVES OVER THE HIGH PLAINS OVERNIGHT...THE STRENGTH OF THE
CONVECTION MAY DECREASE BUT THE COVERAGE OF THE PRECIPITATION AND
ASSOCIATED LOW CEILINGS AND VISIBILITIES WILL INCREASE. MVFR TO LIFR
CONDITIONS CAN BE EXPECTED ACROSS A MAJORITY OF THE ROUTES AS LIGHT
TO MODERATE RAINFALL PERSISTS. WESTERN PORTIONS OF THE 274 TWEB
ROUTE SHOULD INCREASE THROUGH LATE MORNING AS THE SYSTEM MOVE OVER
EASTERN NEBRASKA.

.LBF WATCHES/WARNINGS/ADVISORIES...TORNADO WATCH UNTIL 11 PM CDT...10
PM MDT ALL ZONES EXCEPT SHERIDAN.

&&

CDC

Hazardous weather outlook, Apr 21, 2:59 PM MDT, 2 hours 1 minute before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORTH PLATTE NE
359 PM CDT SAT APR 21 2007

NEZ004>010-022>029-035>038-056>059-069>071-094-221200-
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-
359 PM CDT SAT APR 21 2007 /259 PM MDT SAT APR 21 2007/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WESTERN AND
NORTH CENTRAL NEBRASKA.

.DAY ONE...TONIGHT.

SEVERE THUNDERSTORM DEVELOPMENT WILL BE LIKELY ACROSS AREAS ALONG
AND WEST OF HIGHWAY 83 THROUGH EARLY EVENING...WITH THIS THREAT
SHIFTING EAST OF HIGHWAY 83 THROUGH MIDNIGHT. LARGE
HAIL...DAMAGING WIND GUSTS WILL BE THE PRIMARY WIDESPREAD THREATS
WITH A MAJORITY OF THE STORMS. HOWEVER ISOLATED TORNADOES WILL
ALSO BE POSSIBLE WITH THE GREATEST RISK OCCURRING MAINLY SOUTH OF
HIGHWAY 2...ALONG AND WEST OF HIGHWAY 83...BUT CAN NOT BE
COMPLETELY RULED OUT ELSEWHERE THROUGH THE EVENING. THE SLOWER
MOVEMENT OF THE UPPER SYSTEM DRIVING THE CONVECTION MAY LEAVE SOME
FLOODING PROBLEMS IN PLACE...ESPECIALLY IN TERRAIN FAVORABLE FOR
FLASH FLOODING SUCH AS CANYONS AND NARROW RIVER VALLEYS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

RAINFALL...MODERATE TO HEAVY AT TIMES MAY CONTINUE THROUGH EARLY
SUNDAY AFTERNOON...LEAVING THE MAIN THREAT OF FLOODING IN PLACE. A
SMALL BREAK IN THE PRECIPITATION WILL COME SUNDAY NIGHT THROUGH
MONDAY EVENING BEFORE THE NEXT SYSTEM ARRIVES BY EARLY TUESDAY.
SEVERE THUNDERSTORM DEVELOPMENT MAY BE POSSIBLE TUESDAY...HOWEVER
THE MAIN THREAT LOOKS TO BE FLOODING WITH THE LARGE AMOUNT OF
MOISTURE AVAILABLE TO THIS SYSTEM. FLOOD WATCHES MAY BE POSTED BY
MIDWEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA THROUGH THE LATE EVENING HOURS.

&&

THIS PRODUCT IS NOW AVAILABLE...ALONG WITH OTHER WEATHER...
HYDROLOGICAL AND CLIMATE INFORMATION...AT
HTTP://WWW.CRH.NOAA.GOV/LBF(ALL LOWERCASE)

13

In the hours before

Local storm report, Apr 21, 11:02 AM MDT, 5 hours 58 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1202 PM CDT SAT APR 21 2007

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

1030 PM     TSTM WND GST     2 S COMSTOCK            41.53N 99.24W
04/20/2007  E60 MPH          CUSTER             NE   PUBLIC

&&

BTAYLOR

Local storm report, Apr 21, 11:10 AM MDT, 5 hours 50 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1210 PM CDT SAT APR 21 2007

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

0230 AM     LIGHTNING        ONEILL                 42.46N 98.65W
04/21/2007                   HOLT               NE   BROADCAST MEDIA

            LIGHTNING STRUCK A SATELLITE DISH DIRECTLY BEHIND A RADIO
            STATION BUILDING. DAMAGE WAS REPORTED TO SEVERAL PIECES
            OF ELECTRONIC EQUIPMENT AT THE STATION, AS WELL AS A
            WINDOW BEING BROKE OUT FROM THE THUNDER.

&&

BTAYLOR

Local storm report, Apr 21, 4:08 PM MDT, 52 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
508 PM CDT SAT APR 21 2007

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

0507 PM     HAIL             21 N HYANNIS            42.30N 101.76W
04/21/2007  E0.88 INCH       CHERRY             NE   PUBLIC

            NICKEL SIZED HAIL.

&&

HENDERSON

Local storm report, Apr 21, 4:15 PM MDT, 45 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
515 PM CDT SAT APR 21 2007

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

0510 PM     HAIL             7 SE BROWNLEE           42.22N 100.53W
04/21/2007  E1.75 INCH       CHERRY             NE   PUBLIC

            STARTED MARBLE WITH SOME GOFLBALLS. LASTED AT LEAST 10
            MINUTES, ENDING AT 510PM.

&&

HENDERSON

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 6:36 PM MDT	Severe Thunderstorm Warning	LBF	Hayes, Lincoln	54 min
Apr 20, 7:23 PM MDT	Severe Thunderstorm Warning	LBF	Frontier, Lincoln	67 min
Apr 20, 8:11 PM MDT	Severe Thunderstorm Warning	LBF	Lincoln	64 min
Apr 20, 8:23 PM MDT	Tornado Warning	LBF	Frontier, Lincoln	37 min
Apr 20, 8:50 PM MDT	Severe Thunderstorm Warning	LBF	Custer	40 min
Apr 20, 8:53 PM MDT	Tornado Warning	LBF	Lincoln	37 min
Apr 20, 9:00 PM MDT	Severe Thunderstorm Warning	LBF	Lincoln	30 min
Apr 20, 9:19 PM MDT	Severe Thunderstorm Warning	LBF	Custer	26 min
Apr 20, 9:26 PM MDT	Tornado Warning	LBF	Custer	34 min
Apr 20, 9:30 PM MDT	Severe Thunderstorm Warning	LBF	McPherson	45 min
Apr 20, 9:52 PM MDT	Severe Thunderstorm Warning	LBF	Custer	53 min
Apr 20, 9:57 PM MDT	Tornado Warning	LBF	Custer	48 min
Apr 20, 10:07 PM MDT	Severe Thunderstorm Warning	LBF	Logan, McPherson, Thomas	53 min
Apr 20, 10:12 PM MDT	Severe Thunderstorm Warning	LBF	Hooker	33 min
Apr 20, 10:27 PM MDT	Severe Thunderstorm Warning	LBF	Custer	63 min
Apr 20, 10:35 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	55 min
Apr 20, 11:03 PM MDT	Severe Thunderstorm Warning	LBF	Custer	27 min
Apr 20, 11:27 PM MDT	Tornado Warning	LBF	Cherry	33 min
Apr 20, 11:58 PM MDT	Severe Thunderstorm Warning	LBF	Garfield	47 min
Apr 21, 2:54 AM MDT	Wind Advisory	LBF	Blaine, Boyd, Brown, Chase, Custer, Frontier and 13 more	9 hr
Apr 21, 3:55 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	50 min
Apr 21, 3:59 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	46 min
Apr 21, 4:34 PM MDT	Tornado Warning	LBF	Cherry	26 min
Apr 21, 4:35 PM MDT	Tornado Warning	LBF	Cherry	25 min
Apr 21, 4:39 PM MDT	Severe Thunderstorm Warning	LBF	Brown, Keya Paha	51 min
Apr 21, 4:40 PM MDT	Severe Thunderstorm Warning	LBF	Deuel	50 min
Apr 21, 4:57 PM MDT	Tornado Warning	LBF	Garden, Sheridan	33 min
Apr 21, 4:59 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	31 min
Apr 21, 5:10 PM MDT	Severe Thunderstorm Warning	LBF	Garden	35 min
Apr 21, 5:26 PM MDT	Severe Thunderstorm Warning	LBF	Brown, Keya Paha	64 min
Apr 21, 5:27 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	48 min
Apr 21, 5:27 PM MDT	Tornado Warning	LBF	Garden, Sheridan	33 min
Apr 21, 5:28 PM MDT	Severe Thunderstorm Warning	LBF	Deuel	32 min
Apr 21, 5:35 PM MDT	Severe Thunderstorm Warning	LBF	Arthur	25 min
Apr 21, 5:53 PM MDT	Severe Thunderstorm Warning	LBF	Grant	52 min
Apr 21, 5:57 PM MDT	Severe Thunderstorm Warning	LBF	Deuel, Garden, Keith	63 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 2007 Every severe thunderstorm warning in 2007

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.