Alert archive / Iowa / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 2, NWS Omaha, NE

February 25, 1998Pottawattamie County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Feb 25, 1998, 4:33 PM CST for Pottawattamie County, Iowa. It was in force for 32 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
Feb 25, 1998, 4:33 PM CST (22:33 UTC)
Expired
Feb 25, 1998, 5:05 PM CST
In force
32 min
Issued by
NWS Omaha, NE
Area
Whole counties

County Pottawattamie County, IA

The radar

The Omaha radar (KOAX), 69 km from the middle of the area, began a volume at 22:32 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

Omaha, NE (KOAX), launched 12:00Z, 10.6 hours before the alert went out and 69 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 12:00Z on 1998-02-25Temperature 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 12:00Z on 1998-02-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 81 square meters per square second.1939587897117Sfc1 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
647 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
81 m²/s²
0-3 km storm-relative helicity
12 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 KOMA 252233 RRA
SVROMA
IAC155-252305-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
433 PM CST WED FEB 25 1998

* SEVERE THUNDERSTORM WARNING FOR
  POTTAWATTAMIE COUNTY IN SOUTHWESTERN IOWA

* UNTIL 505 PM CST
 
* SOME LOCATIONS AFFECTED
  WESTON                       BY AROUND 430 PM CST
  MC CLELLAND                  BY AROUND 435 PM CST
  CRESCENT                     BY AROUND 435 PM CST
  UNDERWOOD                    BY AROUND 435 PM CST
  HONEY CREEK                  BY AROUND 440 PM CST

* AT 429 PM CST...A SEVERE THUNDERSTORM WAS INDICATED BY DOPPLER
  RADAR IN THE VICINITY OF MINNEOLA IOWA...10 MILES SOUTHEAST
  OF DOWNTOWN OMAHA MOVING NORTH AT 50 MPH.
    THIS STORM MAY PRODUCE DAMAGING WINDS AND LARGE HAIL.  IF YOU
    ARE IN THE PATH OF THE STORM...TAKE SHELTER IN A REINFORCED
    BUILDING.

    POLLACK

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 Feb 25, 2:08 PM CST, 2 hours 25 minutes earlier.

Area forecast discussion, Feb 25, 2:08 PM CST, 2 hours 25 minutes before
CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
245 PM CST WED FEB 25 1998

MAIN FCST CHALLENGE THS PKG IS CHC FOR MSRBL PCPN IN WRAP ARND
ON S SIDE OF DEEP VERTICALLY STACKED UPR SYS.

SATL SHOWS DRY SLOT EVEN MORE PRONOUNCED THAN YDAS MDL PREDICTIONS.
SFC LO CNTRD NW OF LBF APRS NEARLY VERTICALLY STACKED BNTH UPR
LO IN SAME LOCN.  SLO NEWD PROGRESS OF SYS PREDICTED BY ALL MDLS
SHLD PULL LO LVL MSTR IN WRAP ARND INTO SC NEB BY DAWN WTH NC KS
APRNTLY ESCAPING THE BULK OF IT.  LTL LIFT INDICATED BUT HI RH AND
CD ADVN ENUF FOR SOME PCPN...BUT WL OPT FOR NON MSRBL FLRYS
THU THRU FRI.  KS SECTION FURTHER FROM WRAP ARND SO NO MNTN OF
PCPN PAST THU.

MDLS IN NR TOTAL AGREEMENT PARKING SYSTEM OVR NC NEB AND CNTL SD
THRU FRI.  THAT LOCN LVS GID CWA IN WRAP ARND MSTR & CD ADVN
12-48 HRS AND BEYOND.  STATIONARY VERTICALLY STACKED FCST DEPICTED
BY ALL MDLS LOOKS RSNBL WTH SRN JET SEPARATING FROM SYS.  SEE NO
REAL CHG IN CONDS THU THRU FRI AND EVEN INTO WKEND.

GRI MM 036/039/028/035 1111
HEB MM 038/040/030/035 1111
ODX MM 032/035/026/032 1111
LXN MM 032/035/026/034 1111
BEL ME 040/045/030/038 0---

SCHURR

In the hours before

Special weather statement, Feb 25, 10:57 AM CST, 5 hours 36 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093-
IAZ043-055-056-069-079-080-090-091-261200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1100 AM CST WED FEB 25 1997

...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA...

SPOTTER ACTION...
STORM SPOTTER GROUPS IN EASTERN NEBRASKA AND SOUTHWEST IOWA MAY REQUIRE
ACTIVATION THIS AFTERNOON AND EVENING.

DISCUSSION...
THERE REMAINS A GOOD CHANCE OF THUNDERSTORMS OVER EASTERN NEBRASKA INTO
SOUTHWEST IOWA THIS AFTERNOON OR EARLY THIS EVENING AS A COLD FRONT AND
A STRONG DISTURBANCE IN THE UPPER ATMOSPHERE INTERACT WITH AN
UNSEASONABLY WARM..MOIST AND UNSTABLE AIR MASS. ALTHOUGH UNCOMMON FOR
LATE FEBRUARY...DUE TO THE STRENGTH OF ATMOSPHERIC DYNAMICS AND DEGREE
OF EXPECTED INSTABILITY...A FEW OF THESE STORMS MAY TURN SEVERE WITH
DAMAGING WINDS AND LARGE HAIL.

POWERS
Special weather statement, Feb 25, 3:09 PM CST, 1 hour 24 minutes before
IAZ043-055-056-069-079-080-090-091-NEZ012-015-018-033-034-044-
045-051>053-066>068-089>093-260315-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
309 PM CST WED FEB 25 1998

...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND WESTERN IOWA...

SPOTTER ACTION...
STORM SPOTTER GROUPS IN EXTREME EASTERN NEBRASKA AND SOUTHWEST IOWA
SHOULD REMAIN ALERT THIS EVENING FOR POSSIBLE ACTIVATION.  A CLOSE
EYE SHOULD BE KEPT ON ANY THUNDERSTORMS THAT DEVELOP.  THE AREA TO
WTACH EXTENDS FROM HARTINGTON NEBRASKA SOUTH THROUGH THE
OMAHA/LINCOLN/BEATRICE AREAS AND EASTWARD.

DISCUSSION...
LATE AFTERNOON MOISTURE CONVERGENCE WAS INCREASING IN EXTREME
EASTERN NEBRASKA AND SOUTHWEST IOWA AS WIDELY SCATTERED
THUNDERSTORMS BEGAN TO DEVELOP.  THE STORMS ARE EXCPECTED TO BE FAST
MOVERS...TO THE NORTH AT 30 TO 40 MPH.  SPEED SHEAR IS STRONG IN THE
LOW LAYERS AND THERE IS A POSSIBLITY OF A FEW SPLITTING SUPERCELLS.
THE MAIN THREAT FROM ANY OF THESE STORMS WOULD BE HAIL AND VERY
STRONG WINDS...HOWEVER THE POSSIBLITY OF AN ISOLATED TORNADO CANNOT
BE RULED OUT IN THIS TYPE OF ENVIRONMENT.
BYRD

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 25, 3:53 PM CSTSevere Thunderstorm WarningOAXPottawattamie32 min
Feb 25, 5:22 PM CSTSevere Thunderstorm WarningOAXHarrison, Shelby33 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1998Every severe thunderstorm warning in 1998

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.