Alert archive / Iowa / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 19, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Apr 12, 1998, 7:47 PM CDT for Crawford County, Iowa. It was in force for 33 min. 1 report 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
- Apr 12, 1998, 7:47 PM CDT (00:47 UTC)
- Expired
- Apr 12, 1998, 8:20 PM CDT
- In force
- 33 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Crawford County, IA
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Apr 12, 8:00 PM CDT | Hail 1 | Denison, IA |
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 |
|---|---|---|---|
| Apr 12, 3:30 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 0.8 hours before the alert went out and 114 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
- 390 J/kg
- Mixed-layer CIN
- -83 J/kg
- Mixed-layer LCL
- 1826 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 210 m²/s²
- 0-3 km storm-relative helicity
- 324 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.3
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KDSM 130047 RRA
SVRDSM
IAC047-130120-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
747 PM CDT SUN APR 12 1998
* SEVERE THUNDERSTORM WARNING FOR
SOUTHERN CRAWFORD COUNTY - WEST CENTRAL IOWA
* UNTIL 820 PM CDT
* SOME AREAS AFFECTED
BUCK GROVE
MANILLA
ASPINWALL
DOW CITY
* AT 745 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM NEAR DUNLAP OR 45
MILES NORTHEAST OF COUNCIL BLUFFS MOVING EAST NORTHEAST AT 30 MPH.
* THE STORM WILL BE NEAR BUCK GROVE AND MANILLA BY 810 PM.
LARGE HAIL AND INTENSE RAINFALL IS LIKELY WITH THIS STORM.
STARKWhat 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.
In the hours before
Special weather statement, Apr 12, 3:33 PM CDT, 4 hours 14 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-130230- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 333 PM CDT SUN APR 12 1998 HAZARD--ISOLATED SEVERE THUNDERSTORMS WITH WIND GUSTS TO 65 MPH AND HAIL UP TO GOLFBALL SIZE. AREA OF CONCERN--WEST OF INTERSTATE 35. TIMING DETAILS--BETWEEN 600 AND 1100 PM. METEOROLOGICAL COMMENTS--A LINE OF THUNDERSTORMS HAS BEGUN TO DEVELOP ALONG A DRY LINE IN EASTERN NEBRASKA...ONE OF WHICH HAS BECOME SEVERE ALREADY. THE ATMOSPHERE OVER IOWA CONTINUES TO DESTABILIZE WITH STRONG WINDS AS HIGH AS 70 MPH AT 5000 FEET. ANY THUNDERSTORMS WILL BE ABLE TO BRING THESE WINDS DOWN TO THE SURFACE AND CAUSE DAMAGE. MOISTURE REMAINS SOMEWHAT LIMITED...SO TORNADOES STILL APPEAR UNLIKELY. HOWEVER...RAPID COOLING ALOFT WILL BE ENOUGH TO SUPPORT ISOLATED LARGE HAIL. BY LATE EVENING AS THE DRY LINE MOVES TO AROUND I-35 AND THE LOW LEVELS COOL OFF...THE STORMS SHOULD BEGIN TO WEAKEN. PRECAUTIONS--A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED WEST OF AN ESTHERVILLE-SHENANDOAH LINE UNTIL 900 PM. SPOTTER ACTIVATION SHOULD BE UNDERWAY IN THIS AREA. SPOTTER GROUPS FURTHER EAST SHOULD BE PREPARED FOR ACTIVATION LATER THIS EVENING. ANY SEVERE STORMS SHOULD BE RATHER ISOLATED. PYTLAK
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 7:06 PM CDT | Severe Thunderstorm Warning | DMX | Emmet | 34 min |
| Apr 12, 8:22 PM CDT | Severe Thunderstorm Warning | DMX | Carroll, Crawford | 48 min |
| Apr 12, 8:53 PM CDT | Severe Thunderstorm Warning | DMX | Carroll | 32 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.