Alert archive / Nebraska / Flash Flood Warnings in 1999

Flash Flood Warning 6, NWS North Platte, NE

August 17, 1999Perkins County, Nebraska

NWS North Platte, NE issued this flash flood warning at Aug 17, 1999, 5:09 PM MDT for Perkins County, Nebraska. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 17, 1999, 5:09 PM MDT (23:09 UTC)
Expired: Aug 17, 1999, 8:10 PM MDT
In force: 3 hr
Issued by: NWS North Platte, NE
Area: Whole counties

County Perkins County, NE

The radar

The North Platte radar (KLNX), 152 km from the middle of the area, began a volume at 23:11 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 12:00Z, 11.2 hours before the alert went out and 93 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2024 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: -9 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 
TTAA00 KLBF 172311
FFWLBF
NEC135-180210-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NORTH PLATTE NE
609 PM CDT (509 PM MDT) TUE AUG 17 1999

THE NATIONAL WEATHER SERVICE IN NORTH PLATTE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  PERKINS COUNTY IN SOUTHWESTERN NEBRASKA

* UNTIL 810 PM MDT (910 PM CDT)

* AT 5 PM MDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAIN OVER MUCH OF PERKINS COUNTY...
  MOVING SLOWLY EAST.

* THUNDERSTORMS WITH HEAVY RAINFALL WILL CONTINUE TO MOVE ACROSS
  THE SAME AREAS OF ALREADY SATURATED GROUND IN PERKINS THIS
  EVENING.

DON'T DRIVE ACROSS FLOODED ROADS! MOST FLASH FLOOD DEATHS OCCUR IN
AUTOMOBILES.

DLS

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Aug 17, 12:37 PM MDT, 4 hours 32 minutes earlier.

Area forecast discussion, Aug 17, 12:37 PM MDT, 4 hours 32 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
137 PM CDT TUE AUG 17 1999

...FORECAST CHALLENGE WILL BE COVERAGE OF THUNDERSTORMS TONIGHT...

ETA AND NGM CONTINUE TO AGREE ON VORT CHANNEL TOPPING THE RIDGE BY THIS
EVENING AND MOVING ESE ACROSS SRN NE/NRN KS TONIGHT.  OTHER FACTORS
INCLUDE A SFC FRONT ACROSS NC KS PROGGED TO LIFT NORTHEAST INTO CENTRAL
NEBRASKA THIS EVENING.  DWPTS ABOVE 70 ALSO WILL POOL IN VCNTY OF THIS
FRONT TONIGHT. PREFER ETA WITH MOVEMENT OF VORT CHANNEL AND ASSOC 700
UVV OVER NGM...ALTHOUGH GENERAL AGREEMENT BETWEEN THE TWO INCREASES
CONFIDENCE OF AN MCS DEVELOPMENT TONIGHT.

250 MB DIV WILL SET UP NICELY FROM NW KS INTO EC NEBR BY 06Z WED...AS
RR QUAD OF JET SUPPORTS THIS.  850 CONV ALSO WILL SET UP IN ERN CO BY
00Z TONIGHT AND SPREAD EASTWARD ACROSS NRN KS/SRN NE OVERNIGHT.

A THETA E RIDGE DEVELOPS BY 00Z TONIGHT FROM WRN KS INTO WRN NE AND
ORIENTS INTSELF EAST-WEST ALONG THE NE/KS BORDER OVERNIGHT.  SOME HEAVY
RAINFALL POSSIBLE AS PWS TO NEAR 1.5 INCHES SOUTH AND EAST OF LBF. ALSO
EVENING WILL SUPPORT CHC OF SVR...MAINLY SOUTH OF I-80.  RATHER QUICK
MOVEMENT OF SYSTEM WILL LIMIT ANY SIGNIFICANT RAINFALL AMOUNTS HOWEVER.
WILL INCLUDE LIKELY POPS ACROSS THE SRN HALF OF CWA TONIGHT...AND LOWER
POPS TO THE NORTH.

UPPER RIDGE WILL BUILD WESTWARD THROUGH 48HRS.  ON WEDNESDAY GOOD
SUBSIDENCE BEHIND SYSTEM.  WINDS WILL ONCE AGAIN TURN TO THE NORTH AS
SFC HIGH MOVES SOUTHEAST.  APPROACH OF NRN STREAM SHORTWAVE WILL
PRODUCE AS SFC TROUGH FROM MONTANA INTO ERN WY BY THU MORNING. DRY FCST
WED AND THR.

FAN AND FWC TEMPERATURE GUIDANCE CLOSE WITH LOWER AND MID 80S WED...
WARMING SLIGHTLY INTO THE MID/UPPER 80S THR.

IN THE EXTENDED...CHC OF THUNDERSTORMS FRI.  DRY SAT AND SUN AS UPPER
RIDGE KEEPS MOST OF ENERGY WELL TO THE NORTH OF CWA. HIGHS IN THE MID
AND UPPER 80S IN NE COUNTIES WHILE AROUND 90 ELSEWHERE.  LOWS AROUND
60.

.LBF...NONE.

ROBERG

In the hours before

Local storm report, Aug 17, 3:31 PM MDT, 1 hour 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  NORTH PLATTE NE
431 PM CDT TUE AUG 17 1999

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0350 PM    15 SSW OSHKOSH            NE   TORNADO
08/17/99   GARDEN                         2 TORNADOES REPORTED BY
                                          SPOTTERS

0355 PM    5 W LEWELLEN              NE   TORNADO
08/17/99   GARDEN                         2 TORNADOES REPORTED BY
                                          SPOTTERS

0402 PM    5 SE LEWELLEN             NE   TORNADO
08/17/99   GARDEN                         REPORTED BY SPOTTERS

0411 PM    3 N BIG SPRINGS           NE   TORNADO
08/17/99   DEUEL                          TORNADO REPORTED BY
                                          SPOTTERS

FWM

Local storm report, Aug 17, 3:31 PM MDT, 1 hour 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  NORTH PLATTE NE
431 PM CDT TUE AUG 17 1999

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0350 PM    15 SSW OSHKOSH            NE   TORNADO
08/17/99   GARDEN                         2 TORNADOES REPORTED BY
                                          SPOTTERS

0355 PM    5 W LEWELLEN              NE   TORNADO
08/17/99   GARDEN                         2 TORNADOES REPORTED BY
                                          SPOTTERS

0402 PM    5 SE LEWELLEN             NE   TORNADO
08/17/99   GARDEN                         REPORTED BY SPOTTERS

0411 PM    3 N BIG SPRINGS           NE   TORNADO
08/17/99   DEUEL                          TORNADO REPORTED BY
                                          SPOTTERS

FWM

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 2:44 PM MDT	Severe Thunderstorm Warning	LBF	Garden	61 min
Aug 17, 2:51 PM MDT	Tornado Warning	LBF	Garden	64 min
Aug 17, 3:06 PM MDT	Tornado Warning	LBF	Deuel, Keith	59 min
Aug 17, 3:55 PM MDT	Tornado Warning	LBF	Garden	35 min
Aug 17, 4:00 PM MDT	Severe Thunderstorm Warning	LBF	Hooker	60 min
Aug 17, 4:02 PM MDT	Severe Thunderstorm Warning	LBF	Perkins	63 min
Aug 17, 4:05 PM MDT	Severe Thunderstorm Warning	LBF	Keith	65 min
Aug 17, 4:11 PM MDT	Tornado Warning	LBF	Keith	64 min
Aug 17, 5:04 PM MDT	Severe Thunderstorm Warning	LBF	Perkins	61 min
Aug 17, 5:17 PM MDT	Severe Thunderstorm Warning	LBF	Chase	63 min
Aug 17, 5:32 PM MDT	Tornado Warning	LBF	Chase, Perkins	63 min
Aug 17, 5:42 PM MDT	Severe Thunderstorm Warning	LBF	Lincoln	63 min

Nearby

Flash Flood Warnings in Nebraska, 1999 Every flash flood warning in 1999

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.