Alert archive / Iowa / Tornado Warnings in 1998
Tornado Warning 14, NWS Omaha, NE
NWS Omaha, NE issued this tornado warning at May 15, 1998, 10:03 AM CDT for Shelby County, Iowa. It was in force for 47 min. 12 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 15, 1998, 10:03 AM CDT (15:03 UTC)
- Expired
- May 15, 1998, 10:50 AM CDT
- In force
- 47 min
- Issued by
- NWS Omaha, NE
- Area
- Whole counties
County Shelby County, IA
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 15, 10:05 AM CDT | Thunderstorm Wind 70 | Portsmouth, IA | Two grain bins destroyed. |
| May 15, 10:05 AM CDT | Thunderstorm Wind 70 | Elk Horn, IA | Cement shed, barn, and machine shed destroyed. Another machine shed was also damaged. |
| May 15, 10:05 AM CDT | Thunderstorm Wind 70 | Portsmouth, IA | Large confinement building destroyed. |
| May 15, 10:05 AM CDT | Thunderstorm Wind 70 | Portsmouth, IA | Two sheds destroyed. |
| May 15, 10:07 AM CDT | Thunderstorm Wind 70 | Harlan, IA | Storage building destroyed. |
| May 15, 10:07 AM CDT | Thunderstorm Wind 70 | Harlan, IA | Two walls at the landfill destroyed. |
| May 15, 10:08 AM CDT | Thunderstorm Wind 70 | Jacksonville, IA | Machine shed destroyed. |
| May 15, 10:08 AM CDT | Thunderstorm Wind 70 | Elk Horn, IA | Machine shed destroyed. |
| May 15, 10:10 AM CDT | Thunderstorm Wind 70 | Kirkman, IA | Shed destroyed. |
| May 15, 10:11 AM CDT | Thunderstorm Wind 70 | Earling, IA | Machine shed destroyed. |
| May 15, 10:12 AM CDT | Thunderstorm Wind 70 | Defiance, IA | Shed and hog house destroyed. |
| May 15, 10:13 AM CDT | Thunderstorm Wind 70 | Kirkman, IA | Chicken house roof and two shop doors destroyed. |
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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 15, 7:45 AM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| May 15, 9:45 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 3.1 hours before the alert went out and 97 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.
- Mixed-layer CAPE
- 1194 J/kg
- Mixed-layer CIN
- -370 J/kg
- Mixed-layer LCL
- 1627 m above ground
- 0-6 km bulk shear
- 64 kt
- 0-1 km storm-relative helicity
- -76 m²/s²
- 0-3 km storm-relative helicity
- 26 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KOMA 151503 RRA TOROMA IAC165-151550- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1003 AM CDT FRI MAY 15 1998 THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * TORNADO WARNING FOR... SHELBY COUNTY IN SOUTHWESTERN IOWA * UNTIL 1050 AM CDT * AT 959 AM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A POSSIBLE TORNADO 37 MILES NORTHEAST OF DOWNTOWN OMAHA OR 3 MILES SOUTH SOUTHWEST OF WESTPHALIA MOVING NORTH AT 50 MPH. DAMAGE FROM A POSSIBLE TORNADO WAS REPORTED IN THE SHELBY AREA. * THE TORNADO IS EXPECTED TO BE NEAR... WESTPHALIA AT 1002 AM CDT PANAMA AT 1000 AM CDT EARLING AT 1005 AM CDT DEFIANCE AT 1010 AM CDT PERSONS IN THE WARNED AREA SHOULD TAKE SHELTER IN A BASEMENT IF AVAILABLE. OTHERWISE GO TO A SMALL INTERIOR ROOM ON THE LOWEST FLOOR. CARS AND MOBILE HOMES SHOULD BE ABANDONED. MILLER
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.
In the hours before
Special weather statement, May 15, 5:00 AM CDT, 5 hours 3 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-161200- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 500 AM CDT FRI MAY 15 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER ACTIVATION MAY BE NEEDED OVER EASTERN NEBRASKA AND SOUTHWEST IOWA TODAY. DISCUSSION... A COLD FRONT EXTENDING ACROSS CENTRAL NEBRASKA WILL MOVE EASTWARD AS A STRONG UPPER LEVEL DISTURBANCE OVER THE TEXAS PANHANDLE LIFTS NORTHEAST INTO SOUTHWEST IOWA BY EVENING. THESE FEATURES COMBINED WITH A MOIST AND VERY UNSTABLE AIRMASS OVER THE REGION WILL BRING PERIODS OF THUNDERSTORMS TO THE REGION TODAY. THE PRIMARY THREAT FROM THESE STORMS WOULD BE LARGE HAIL AND DAMAGING WINDS. LJH
Special weather statement, May 15, 5:00 AM CDT, 5 hours 3 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-161200- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 500 AM CDT FRI MAY 15 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER ACTIVATION MAY BE NEEDED OVER EASTERN NEBRASKA AND SOUTHWEST IOWA TODAY. DISCUSSION... A COLD FRONT EXTENDING ACROSS CENTRAL NEBRASKA WILL MOVE EASTWARD AS A STRONG UPPER LEVEL DISTURBANCE OVER THE TEXAS PANHANDLE LIFTS NORTHEAST INTO SOUTHWEST IOWA BY EVENING. THESE FEATURES COMBINED WITH A MOIST AND VERY UNSTABLE AIRMASS OVER THE REGION WILL BRING PERIODS OF THUNDERSTORMS TO THE REGION TODAY. THE PRIMARY THREAT FROM THESE STORMS WOULD BE LARGE HAIL AND DAMAGING WINDS. LJH
The office that day
Everything else NWS Omaha, NE issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 15, 8:58 AM CDT | Severe Thunderstorm Warning | OAX | Fremont, Mills | 62 min |
| May 15, 8:58 AM CDT | Severe Thunderstorm Warning | OAX | Page | 62 min |
| May 15, 9:10 AM CDT | Severe Thunderstorm Warning | OAX | Pottawattamie | 65 min |
| May 15, 9:16 AM CDT | Severe Thunderstorm Warning | OAX | Montgomery | 64 min |
| May 15, 9:34 AM CDT | Severe Thunderstorm Warning | OAX | Harrison, Shelby | 61 min |
| May 15, 9:47 AM CDT | Severe Thunderstorm Warning | OAX | Monona | 63 min |
| May 15, 10:13 AM CDT | Severe Thunderstorm Warning | OAX | Pottawattamie | 32 min |
| May 15, 10:50 AM CDT | Severe Thunderstorm Warning | OAX | Monona | 30 min |
| May 15, 11:28 AM CDT | Severe Thunderstorm Warning | OAX | Mills, Pottawattamie | 62 min |
| May 15, 12:27 PM CDT | Tornado Warning | OAX | Pottawattamie, Shelby | 33 min |
| May 15, 2:58 PM CDT | Severe Thunderstorm Warning | OAX | Mills, Montgomery, Pottawattamie | 62 min |
| May 15, 3:01 PM CDT | Severe Thunderstorm Warning | OAX | Harrison | 49 min |
| May 15, 3:10 PM CDT | Severe Thunderstorm Warning | OAX | Monona | 50 min |
| May 15, 3:10 PM CDT | Severe Thunderstorm Warning | OAX | Shelby | 50 min |
Nearby
Tornado Warnings in Iowa, 1998Every tornado warning in 1998Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.