Alert archive / Nebraska / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 302, NWS Omaha, NE

August 20, 2002Otoe County, Nebraska; Fremont County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Aug 20, 2002, 2:45 AM CDT for Otoe County, Nebraska; Fremont County, Iowa. It was in force for 45 min. 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 20, 2002, 2:45 AM CDT (07:45 UTC)
Expired
Aug 20, 2002, 3:30 AM CDT
In force
45 min
Issued by
NWS Omaha, NE
Area
Counties, with a storm outline in the text

Counties Fremont County, IA, Otoe County, NE

The radar

The Omaha radar (KOAX), 81 km from the middle of the area, began a volume at 07:46 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 nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 7.8 hours before the alert went out and 81 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-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2002-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2002-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 99 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1663 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
99 m²/s²
0-3 km storm-relative helicity
217 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

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 Omaha, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 19, 2:35 PM CDT, 12 hours 10 minutes earlier.

Area forecast discussion, Aug 19, 2:35 PM CDT, 12 hours 10 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
235 PM CDT MON AUG 19 2002

MAIN FORECAST CONCERN IS POTENTIAL FOR SEVERE WEATHER WITH TSTMS
LATE TNGT IN THE SRN ZONES...SPREADING NORTH THROUGH THE AREA ON
TUE.  SFC ANLYS EARLY THIS AFTN SHOWED FNT STALLED OVER KS AND
MO...WITH DEWPOINTS IN THE 70S TO THE S OF BOUNDARY.  HIGH PRES
RIDGE WILL MOVE EWD...AND PRESSURES WILL FALL OVER THE WRN HIGH
PLAINS...HELPING LIFT FNT NWD.  ISENTROPIC LIFT SHOULD BE STRONG
ENOUGH TO GENERATE PCPN AT LEAST IN SERN NE.  HAVE HIGHEST POPS
...40 PERCENT...ALONG KS BORDER.  EXPECT LOWS TNGT TO VERY FROM
MID 50S NRN ZONES TO LOWER AND MID 60S IN THE S.  TEMPS SHOULD
BE RISING LATE TNGT WITH CLOUDS INCREASING.

ON TUE...BUMPED UP POPS TO LIKELY IN SERN HALF OF AREA AND TO
50 PERCENT IN THE N.  SHEAR STRONG ENOUGH TO SUPPORT SUPERCELLS
IF BASES ARE LOW ENOUGH.  STORMS IN THE MORNING LIKELY TO BE
ELEVATED...WITH HAIL THE MAIN THREAT.  WARMER AIR WILL TRY TO
WORK ITS WAY IN...ESPECIALLY SRN ZONES AND HAVE CONTINUED THE
TREND ABOVE NGM MOS FOR HIGHS TUE AFTN.  THIS DEPENDANT ON AT
LEAST SOME BREAKS IN THE CLOUD COVER.  FNT REMAINS IN THE AREA
OR CLOSE TO THE AREA INTO LATE WEEK...AND PATTERN LOOKS RATHER
UNSETTLED.  HEIGHT FALLS OVER THE WRN U.S. WILL KEEP OUR AREA
IN SWLY FLOW AT 500 MB...AND MODELS CONTINUE TO SHOW QUITE A
BIT OF MOISTURE AT TIMES AROUND THE 700 MB LEVEL.  SO...KEPT
AT LEAST SLGT CHANCE IN FOR WED-FRI.  BELIEVE QPF FROM AVN IS
A BIT OVERDONE THU NGT...BUT DID GO WITH 50 PERCENT POPS OVER
NERN NE.  BOUNDARY SHOULD PUSH SEWD AS A CDFNT ON FRI...WITH
HIGH PRES BUILDING INTO MT.  LEFT SAT-MON PERIOD DRY FOR NOW.
FIRST DRAFT OF THE WORK ZFP WAS SENT EARLIER.

.OMA...NONE.
MILLER

In the hours before

Local storm report, Aug 19, 8:49 PM CDT, 5 hours 56 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
849 PM CDT MON AUG 19 2002

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

0840 PM    1 SW DUNBAR               NE   .75 INCH HAIL
08/19/02   OTOE                           REPORTED BY STORM
                                          SPOTTER.
Local storm report, Aug 19, 10:12 PM CDT, 4 hours 33 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1012 PM CDT MON AUG 19 2002

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

0735 PM    SYRACUSE                  NE   1 INCH HAIL
08/19/02   OTOE                           REPORTED BY STORM
                                          SPOTTER.

0814 PM    2 N HAMBURG               IA   1.5 INCH HAIL
08/19/02   FREMONT                        REPORTED BY PUBLIC.
                                          EVENT DURATION 5 MINUTES.

0840 PM    1 SW DUNBAR               NE   .75 INCH HAIL
08/19/02   OTOE                           REPORTED BY STORM
                                          SPOTTER.
Local storm report, Aug 20, 2:12 AM CDT, 33 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
212 AM CDT TUE AUG 20 2002

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

0202 AM    (LNK)LINCOLN ARPT         NE   .75 INCH HAIL
08/20/02   LANCASTER                      ASOS OBSERVATION

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 7:29 PM CDTSevere Thunderstorm WarningOAXOtoe31 min
Aug 19, 8:00 PM CDTSevere Thunderstorm WarningOAXOtoe30 min
Aug 19, 8:06 PM CDTSevere Thunderstorm WarningOAXLancaster54 min
Aug 19, 8:31 PM CDTSevere Thunderstorm WarningOAXOtoe59 min
Aug 19, 8:41 PM CDTSevere Thunderstorm WarningOAXJohnson64 min
Aug 19, 9:32 PM CDTSevere Thunderstorm WarningOAXOtoe43 min
Aug 20, 1:27 AM CDTSevere Thunderstorm WarningOAXCass, Lancaster33 min
Aug 20, 1:58 AM CDTSevere Thunderstorm WarningOAXLancaster32 min
Aug 20, 2:05 AM CDTSevere Thunderstorm WarningOAXOtoe40 min
Aug 20, 2:30 AM CDTSevere Thunderstorm WarningOAXLancaster30 min
Aug 20, 3:05 AM CDTSevere Thunderstorm WarningOAXLancaster25 min
Aug 20, 4:05 AM CDTFlash Flood WarningOAXOtoe6 hr
Aug 20, 5:48 AM CDTSevere Thunderstorm WarningOAXSarpy27 min
Aug 20, 6:14 AM CDTSevere Thunderstorm WarningOAXSarpy31 min
Aug 20, 6:49 AM CDTSevere Thunderstorm WarningOAXCass41 min
Aug 20, 2:17 AM CDTSevere Thunderstorm WarningOAXMills, Montgomery43 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 2002Severe Thunderstorm Warnings in Iowa, 2002Every severe thunderstorm warning in 2002

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.