Alert archive / Iowa / Tornado Warnings in 1999

Tornado Warning 26, NWS Omaha, NE

May 16, 1999Mills County, Iowa

NWS Omaha, NE issued this tornado warning at May 16, 1999, 2:52 PM CDT for Mills County, Iowa. It was in force for 33 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
May 16, 1999, 2:52 PM CDT (19:52 UTC)
Expired
May 16, 1999, 3:25 PM CDT
In force
33 min
Issued by
NWS Omaha, NE
Area
Whole counties

County Mills County, IA

The radar

The Omaha radar (KOAX), 70 km from the middle of the area, began a volume at 19:55 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.

What was reported inside it

TimeReportWhereRemark
May 16, 2:55 PM CDTHail 0.75Pacific Jct, IA
May 16, 3:05 PM CDTTornado F0Pacific Jct, IAThis tornado first touched down south of Plattsmouth Nebraska then crossed the Missouri River just southwest of Pacific Junction. It downed trees near I-29 and highway 34 and damaged a house before dissipating.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 7.9 hours before the alert went out and 226 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, Topeka, KS at 12:00Z on 1999-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3044 joules per kilogram.LCLLFCEL10008507005003002001001 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, Topeka, KS at 12:00Z on 1999-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 562 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
3044 J/kg
Mixed-layer CIN
-186 J/kg
Mixed-layer LCL
631 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
562 m²/s²
0-3 km storm-relative helicity
521 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.9

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at May 16, 12:01 PM CDT, 2 hours 51 minutes earlier.

Area forecast discussion, May 16, 12:01 PM CDT, 2 hours 51 minutes before
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In the hours before

Local storm report, May 16, 10:35 AM CDT, 4 hours 17 minutes before
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Local storm report, May 16, 10:35 AM CDT, 4 hours 17 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1035 AM CDT SUN MAY 16 1999

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

0715 AM    8 S PILGER                NE   .75 INCH HAIL
05/16/99   STANTON
Special weather statement, May 16, 11:35 AM CDT, 3 hours 17 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093-
IAZ043-055-056-069-079-080-090-091-171200-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1135 AM CDT SUN MAY 16 1999

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

SPOTTER ACTION...
STORM SPOTTER ACTIVATION WILL PROBABLY BE REQUIRED ACROSS PARTS OF
EASTERN NEBRASKA AND SOUTHWEST IOWA THIS AFTERNOON AND EVENING.
THE RISK IS HIGHEST SOUTHEAST OF A LINE FROM AROUND DAVID CITY TO
WEST POINT AND ONAWA IOWA...MAINLY BETWEEN 4 PM AND 10 PM.  HEAVY
RAIN SHOULD BE THE PRIMARY THREAT AFTER 11 PM.

DISCUSSION...
A COLD FRONT EXTENDS FROM SOUTHWEST MINNESOTA INTO EASTERN NEBRASKA
THEN INTO CENTRAL KANSAS.  THE ATMOSPHERE IS MOIST AND VERY UNSTABLE
AHEAD OF THE FRONT.  THUNDERSTORMS MAY DEVELOP NEAR OR AHEAD OF THE
FRONT THIS AFTERNOON AND EVENING.  SOME OF THESE STORMS MAY BECOME
SEVERE...ESPECIALLY IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.

LARGE HAIL IS THE PRIMARY THREAT...BUT SOME SUPERCELL STORMS AND AN
ISOLATED TORNADO OR TWO CAN NOT BE RULED OUT.  DAMAGING WINDS ARE
ALSO POSSIBLE.

MILLER
Local storm report, May 16, 1:21 PM CDT, 1 hour 31 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
121 PM CDT SUN MAY 16 1999

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

0630 AM    3 NW PRIMROSE             NE    1.75 INCH HAIL
05/16/99   BOONE

0715 AM    8 S PILGER                NE    .75 INCH HAIL
05/16/99   STANTON

0715 AM    6 W BANCROFT              NE    .75 INCH HAIL
05/16/99   CUMING

MILLER
Local storm report, May 16, 1:21 PM CDT, 1 hour 31 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
121 PM CDT SUN MAY 16 1999

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

0630 AM    3 NW PRIMROSE             NE    1.75 INCH HAIL
05/16/99   BOONE

0715 AM    8 S PILGER                NE    .75 INCH HAIL
05/16/99   STANTON

0715 AM    6 W BANCROFT              NE    .75 INCH HAIL
05/16/99   CUMING

MILLER

The office that day

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

IssuedProductOfficeCountiesLasted
May 15, 10:56 PM CDTSevere Thunderstorm WarningOAXSaline49 min
May 15, 11:06 PM CDTSevere Thunderstorm WarningOAXButler, Colfax, Platte49 min
May 15, 11:57 PM CDTSevere Thunderstorm WarningOAXCuming, Stanton48 min
May 16, 6:21 AM CDTSevere Thunderstorm WarningOAXBoone49 min
May 16, 6:24 AM CDTSevere Thunderstorm WarningOAXColfax, Platte51 min
May 16, 6:32 AM CDTSevere Thunderstorm WarningOAXStanton63 min
May 16, 6:52 AM CDTSevere Thunderstorm WarningOAXCuming48 min
May 16, 2:57 PM CDTSevere Thunderstorm WarningOAXWashington48 min
May 16, 3:07 PM CDTTornado WarningOAXWashington33 min
May 16, 6:27 PM CDTSevere Thunderstorm WarningOAXNemaha, Pawnee, Richardson33 min
May 16, 1:05 AM CDTSevere Thunderstorm WarningOAXHarrison, Pottawattamie, Shelby30 min
May 16, 7:33 AM CDTSevere Thunderstorm WarningOAXMonona32 min
May 16, 2:42 PM CDTSevere Thunderstorm WarningOAXMills33 min
May 16, 3:19 PM CDTSevere Thunderstorm WarningOAXMonona36 min
May 16, 3:23 PM CDTTornado WarningOAXMills37 min
May 16, 3:32 PM CDTTornado WarningOAXMonona33 min
May 16, 3:37 PM CDTTornado WarningOAXHarrison48 min
May 16, 3:47 PM CDTTornado WarningOAXPottawattamie48 min
May 16, 3:56 PM CDTTornado WarningOAXMills34 min
May 16, 4:22 PM CDTTornado WarningOAXHarrison48 min
May 16, 4:24 PM CDTTornado WarningOAXPottawattamie51 min
May 16, 4:27 PM CDTTornado WarningOAXMills33 min
May 16, 5:01 PM CDTTornado WarningOAXShelby44 min
May 16, 5:11 PM CDTTornado WarningOAXHarrison34 min
May 16, 5:14 PM CDTTornado WarningOAXPottawattamie46 min
May 16, 5:33 PM CDTTornado WarningOAXMills37 min
May 16, 5:45 PM CDTSevere Thunderstorm WarningOAXShelby35 min
May 16, 6:00 PM CDTTornado WarningOAXPottawattamie30 min
May 16, 6:11 PM CDTSevere Thunderstorm WarningOAXMills, Montgomery49 min
May 16, 6:33 PM CDTTornado WarningOAXPottawattamie32 min
May 16, 6:37 PM CDTSevere Thunderstorm WarningOAXMills, Montgomery48 min
May 16, 6:43 PM CDTFlash Flood WarningOAXPottawattamie6 hr
May 16, 6:55 PM CDTTornado WarningOAXMills, Montgomery35 min

Nearby

Tornado Warnings in Iowa, 1999Every tornado warning in 1999Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.