Alert archive / Nebraska / Flash Flood Warnings in 1999

Flash Flood Warning 4, NWS North Platte, NE

August 10, 1999Perkins County, Nebraska

NWS North Platte, NE issued this flash flood warning at Aug 10, 1999, 8:01 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 10, 1999, 8:01 PM MDT (02:01 UTC)
Expired: Aug 10, 1999, 11:00 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 02:05 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, 2.0 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: 1568 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 1522 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: 110 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KLBF 110201
FFWLBF
NEC135-110500-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NORTH PLATTE NE
901 PM CDT (801 PM MDT) TUE AUG 10 1999

THE NATIONAL WEATHER SERVICE IN NORTH PLATTE HAS ISSUED A

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

* UNTIL 1100 PM MDT (MIDNIGHT CDT)

* AT 8 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SCATTERED THUNDERSTORMS PRODUCING VERY HEAVY RAINFALL CONTINUE TO
  REDEVELOP AND MOVE ACROSS PERKINS COUNTY.  PORTIONS OF SOUTHERN
  PERKINS COUNTY HAVE RECEIVED OVER 6 INCHES OF RAIN WITH MORE
  STORMS MOVING IN FROM COLORADO.

* THROUGH 10 PM MDT...CLUSTERS OF THUNDERSTORMS WILL CONTINUE TO
  MOVE THROUGH THE AREA WITH AN ADDITIONAL 2 TO 3 INCHES POSSIBLE
  PRODUCING LOCALIZED STORM RAINFALL TOTALS OF 4 TO 8 INCHES.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGER OF FLOODING.  FARM ROADS AND SOME SECONDARY ROADS WILL
LIKELY BECOME IMPASSABLE.

COLE

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 10, 1:55 PM MDT, 6 hours 6 minutes earlier.

Area forecast discussion, Aug 10, 1:55 PM MDT, 6 hours 6 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
255 PM CDT TUE AUG 10 1999

WEAK SHORTWAVE AND DIFFLUENT UPPER LEVEL FLOW PRODUCED CLOUDS AND
SHOWERS FROM NORTHEAST CO INTO SOUTHERN PANHANDLE THIS MORNING AND AREA HAS
INTENSIFIED INTO SCATTERED TSRA INTO FAR SW CWFA EARLY THIS AFTERNOON.
STRONGER SHORTWAVE EVIDENT ON WV IMAGERY AND LIGHTNING DATA FURTHER
UPSTREAM MOVING OUT OF NEW MEXICO INTO COLORADO. THIS FEATURE SHOULD
COMBINE WITH INCREASING LOW LEVEL JET TO PRODUCE WIDESPREAD
THUNDERSTORMS ACROSS SOUTHWEST AND WEST CENTRAL NEBRASKA TONIGHT.

AVN AND NGM HAVE BETTER HANDLE ON THESE SHORTWAVES COMPARED TO ETA
LOOKING AT SATELLITE DATA AT 18Z. ALL MODELS CONTINUE TO HAVE
SHORTWAVES IN SW FLOW ALOFT EJECTING N-NE INTO MOISTURE PLUME THAT
EXTENDS NWD FROM OLD MEXICO INTO NORTHERN CO. MAIN H5 TROUGH OVER CA
GRADUALLY WEAKENS AND MOVES NE THROUGH NEB ON THURSDAY. ETA IS
FASTEST WITH PROGRESSION OF THIS FEATURE...BUT ALSO WEAKEST. AT
SURFACE...ETA ALSO IS FASTER WITH ASSOCIATED LOW ACROSS S DAKOTA
INTO MN BY THURSDAY AM...WHILE NGM/ETA HOLD IT BACK IN EASTERN SOUTH
DAKOTA. WILL GENERALLY FOLLOW BLEND OF AVN/NGM...LEANING TOWARD
HIGHER FAN POPS FOR THUNDERSTORM CHANCES TONIGHT THROUGH WEDNESDAY
NIGHT.

WILL HAVE TO HAVE SCATTERED WORDING FOR ONGOING CONVECTION AT
ISSUANCE IN SW AND FAR W ZONES...OTHERWISE...PLANNED ON LIKELY POPS
FOR S HALF TONIGHT WHEN BEST MID LEVEL Q-VECTOR CONVERGENCE AND 850
MB MOISTURE FLUX CONVERGENCE MOVES OVER REGION. MOS LOW TEMPERATURES
LOOK ACCEPTABLE. ON WEDNESDAY...BEST INSTABILITY SHIFTS MAINLY EAST
AND S OF FORECAST AREA...BUT FORCING AHEAD OF MAIN SHORTWAVE WILL BE
ENOUGH TO WARRANT ISOLATED TO LOW SCATTERED POPS. TEMPERATURES WILL
BE SIMILAR TO TODAY AND WILL STAY CLOSE TO GUIDANCE. WILL INCLUDE
LOW POPS IN NORTH FOR EARLY THURSDAY AS SHORTWAVE MOVES THROUGH
SD...BUT KEEP DRY FORECAST FURTHER SOUTH. SHOULD BE SLIGHTLY COOLER
TEMPS WITH WEAK CAA BEHIND SURFACE TROUGH AND GUIDANCE VALUES ABOUT
5 DEG BELOW WEDNESDAY ACCEPTABLE.

IN EXTENDED...FLAT UPPER LEVEL RIDGE REBOUNDS FOR FRIDAY AND
SATURDAY. FLOW BECOMES FASTER AND MORE ZONAL BY SUNDAY WITH LEE
TROUGHING POSSIBLY PRODUCING SOME PCPN...BUT BULK OF UPPER LEVEL
ENERGY SHOULD STAY TO NORTH AND WILL LEAVE OUT MENTION OF PCPN FOR
NOW.

.LBF...NONE

SHEETS

In the hours before

Local storm report, Aug 10, 3:57 PM MDT, 4 hours 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  NORTH PLATTE NE
457 PM CDT TUE AUG 10 1999

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

0452 PM    GRANT                     NE   1.00 INCH HAIL
08/10/99   PERKINS

DP

Local storm report, Aug 10, 3:57 PM MDT, 4 hours 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  NORTH PLATTE NE
457 PM CDT TUE AUG 10 1999

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

0452 PM    GRANT                     NE   1.00 INCH HAIL
08/10/99   PERKINS

DP

Local storm report, Aug 10, 7:04 PM MDT, 57 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  NORTH PLATTE NE
804 PM CDT TUE AUG 10 1999

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

0700 PM    6 SSE ROSCOE              NE   1.75 INCH HAIL
08/10/99   KEITH

DP

Local storm report, Aug 10, 7:04 PM MDT, 57 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  NORTH PLATTE NE
804 PM CDT TUE AUG 10 1999

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

0700 PM    6 SSE ROSCOE              NE   1.75 INCH HAIL
08/10/99   KEITH

DP

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 7:25 PM MDT	Flash Flood Warning	LBF	Keith	3 hr
Aug 10, 8:50 PM MDT	Severe Thunderstorm Warning	LBF	Lincoln	45 min
Aug 10, 9:24 PM MDT	Severe Thunderstorm Warning	LBF	Hayes, Lincoln	61 min
Aug 10, 10:09 PM MDT	Severe Thunderstorm Warning	LBF	Frontier	61 min
Aug 10, 10:40 PM MDT	Flash Flood Warning	LBF	Keith, Perkins	7 hr

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.