Alert archive / Iowa / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 175, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Aug 26, 1990, 7:43 AM CDT for Allamakee County, Iowa. It was in force for 37 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
- Aug 26, 1990, 7:43 AM CDT (12:43 UTC)
- Expired
- Aug 26, 1990, 8:20 AM CDT
- In force
- 37 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Allamakee County, IA
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 26, 7:50 AM CDT | Thunderstorm Wind 50 | Allamakee, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.
The nearest sounding before it
Minneapolis, MN (KSTC), launched 12:00Z, 0.7 hours before the alert went out and 249 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
- 21 J/kg
- Mixed-layer CIN
- -644 J/kg
- Mixed-layer LCL
- 1569 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- -132 m²/s²
- 0-3 km storm-relative helicity
- 1 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KALO 261243
SVRALO
IAC005-261345-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE WATERLOO IA
743 AM CDT SUN AUG 26 1990
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 845 AM CDT FOR PEOPLE IN THE FOLLOWING
COUNTY
IN THE NORTHEAST PART OF IOWA
ALLAMAKEE
AT TIME 735 AM CDT WEATHER RADAR INDICATED A SEVERE THUNDERSTORM
IN THE NORTHERN PORTION OF ALLAMAKEE COUNTY. THE SEVERE
THUNDERSTORM WAS MOVING SOUTHEAST AT 20 MILES AN HOUR AND WILL
BE EFFECTING THE TOWNS OF WAUKON...LANSING AND HARPERS FERRY.
YOU SHOULD MOVE INSIDE A REINFORCED BUILDING. STAY AWAY FROM
WINDOWS. DO NOT USE TELEPHONES OR ELECTRICAL APPLIANCES UNTIL
AFTER THE STORM PASSES.
SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES
WITH LITTLE OR NO ADVANCE WARNING.
JOHNSONWhat 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, Aug 26, 4:48 AM CDT, 2 hours 55 minutes before
IAZALL-261030- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 445 AM CDT SUN AUG 26 1990 AN ISOLATED STRONG THUNDERSTORM WAS OVER NORTHWEST IOWA. AT 428 AM... THE THUNDERSTORM WAS 45 MILES SOUTHWEST OF FORT DODGE...OR JUST SOUTH- WEST OF LAKE VIEW. THIS STORM IS LIKELY PRODUCING EXTREMELY HEAVY RAINS...PEA TO MARBLE SIZE HAIL AND WIND GUSTS OF 30 TO 40 MILES AN HOUR. THE STORM WAS MOVING NORTHEAST AT 20 MILES AN HOUR. THE STORM WILL BE MOVING THROUGH THE LAKE VIEW AREA TO AROUND ROCKWELL CITY BY 530 AM. THIS STORM WAS PART OF A CLUSTER OF THUNDERSTORMS THAT WAS LOCATED BETWEEN IDA GROVE AND JEFFERSON. OTHER ISOLATED SHOWERS AND THUNDER- STORMS WERE OVER WEST CENTRAL IOWA NEAR DENISON AND IN THE NORTHWEST JUST SOUTHEAST OF SIOUX FALLS SOUTH DAKOTA. THESE SHOWERS AND STORMS WERE ALSO MOVING NORTHEAST AT 20 MILES AN HOUR. THUNDERSTORMS WERE ALSO OCCURRING OVER SOUTHERN MINNISOTA...JUST NORTH THE BORDER...NORTH OF MASON CITY. DLF
Special weather statement, Aug 26, 5:48 AM CDT, 1 hour 55 minutes before
IAZALL-261130- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 545 AM CDT SUN AUG 26 1990 A CLUSTER OF STRONG THUNDERSTORMS WAS OVER NORTH CENTRAL AND NORTHWEST IOWA. AT 530 AM...THE THUNDERSTORMS WERE LOCATED FROM 10 MILES SOUTH OF FORT DODGE TO ROCKWELL CITY...25 MILES SOUTHWEST OF FORT DODGE. THE CALHOUN COUNTY SHERIFFS OFFICE REPORTED THAT BRIEF HEAVY RAINS AND WINDS UP TO 40 MILES AN HOUR OCCURRED WITH THE STORMS AS THE PASSED OVER ROCKWELL CITY. THE STORMS WERE MOVING NORTHEAST AT 20 MILES AN HOUR. THE STORMS WILL BE PASSING THROUGH MANSON AND FORT DODGE TO JUST SOUTH OF HUMBOLT AND EAGLE GROVE BY 630 AM. IN ADDITION TO THE HEAVY RAINS AND GUSTY WINDS ...SOME SMALL HAIL IS POSSIBLE FROM THESE STORMS. ISOLATED THUNDERSTORMS WERE ALSO OVER SOUTHWEST IOWA...EAST OF COUNCIL BLUFFS NEAR AVOCA AND IN NORTHWEST IOWA...SOUTHEAST OF SIOUX FALLS SOUTH DAKOTA...NEAR SIBLEY. THESE STORMS WERE AL+SO MOVING NORTHEAST AT 20 MILES AN HOUR. DLF
Special weather statement, Aug 26, 6:01 AM CDT, 1 hour 42 minutes before
IAZALL-262300- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 600 AM CDT SUN AUG 26 1990 ...HOT TEMPERATURES AND UNPLEASANT HUMIDITY WILL OCCUR ACROSS IOWA... TYPICAL AUGUST WEATHER IS EXPECTED OVER THE STATE FROM MIDDAY INTO THE EVENING HOURS AS TEMPERATURES CLIMB INTO THE UPPER 80S TO MIDDLE 90S. THE COMBINATION OF HEAT AND HUMIDITY WILL PRODUCE HEAT INDICES IN THE UPPER 90S IN EXTREME NORTHEAST IOWA TO AROUND 107 DEGREES IN THE SOUTHWEST QUARTER. PEOPLE WORKING OUT-OF-DOORS...THOSE LIVING IN UN-AIRCONDITIONED SPACES ...THE ELDERLY...AND PEOPLE IN POOR HEALTH SHOULD TAKE PRECAUTIONS. PROLONGED EXPOSURE TO THESE CONDITIONS OR STRENUOUS PHYSICAL ACTIVITY CAN LEAD TO HEAT EXHAUSTION OR POSSIBLE HEAT STROKE. PEOPLE ATTENDING OUTDOOR EVENTS SUCH AS THE IOWA STATE FAIR SHOULD WEAR LIGHT-COLORED...LOOSE-FITTING CLOTHING...HAVE PROTECTION FROM THE SUN AND DRINK PLENTY OF NON-ALCOHOLIC LIQUIDS. SLIGHTLY HIGHER HEA;T INDICES ARE EXPECTED MONDAY. MYERS
Special weather statement, Aug 26, 6:50 AM CDT, 53 minutes before
IAZALL-261230- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 645 AM CDT SUN AUG 26 1990 AN ISOLATED INTENSE THUNDERSTOM WAS OVER NORTH CENTRAL IOWA. AT 535 AM ...THE STORM WAS LOCATED NORTH OF FORT DODGE...JUST SOUTH OF HUMBOLT. HAIL...WINDS UPTO 40 MILES AN HOUR AND EXTREMELY HEAVY RAINS WILL OCCUR WITH THIS STORM AS IT MOVES NORTHEAST AT 30 MILES AN HOUR. BY 730 AM THE STORM WILL BE LOCATED SOUTH OF MASON CITY NEAR BELMOND. OTHER ISOLATED THUNDERSTORMS WITH VERY HEAVY RAINS WERE LOCATED IN NORTH CENTRAL IOWA...SOUTHWEST OF MASON CITY NEAR BRITT AND JUST SOUTH- WEST OF FORT DODGE. IN WEST CENTRAL IOWA...AN ISOLATED THUNDERSTORM WITH VERY HEAVY RAIdNS WAS LOCATED 70 MILES WEST OF DES MOINES NEAR AUDUBON. THESE STORMS WERE ALSO MOVING NORTHEAST AT 30 MILES AN HOUR. DLF
Special weather statement, Aug 26, 7:35 AM CDT, 8 minutes before
IAZ002-003-007-261330- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WATERLOO IA 730 AM CDT SUN AUG 26 1990 AT 725 AM CDT A STRONG THUNDERSTORM WAS LOCATED IN THE NORTHERN HALF OF ALLAMAKEE COUNTY IN EXTREME NORTHEAST IOWA. THIS THUNDERSTORM CAN PRODUCE EXTREMELY HEAVY RAINS...HAIL AND WIND GUSTS TO 40 TO 50 MILES AN HOUR. THE STORM WAS MOVING SOUTHEAST AT 20 MILES AN HOUR AND WILL EFFECT THE TOWNS OF LANSING...NEW ALBIN AND HARPERS FERRY ALONG THE MISSISSIPPI RIVER BETWEEN 730 AND 800 AM CDT. ANOTHER STRONG THUNDERSTORM WAS BETWEEN BELMOND AND DOWS...50 MILES NORTHWEST OF WATERLOO. THIS STORM IS MOVING EAST AT 20 MILES AN HOUR AND CAN PRODUCE HAIL...EXTREMELY HEAVY RAINS AND GUSTY SURFACE WIND AS IT ENTERS WESTERN FRANKLIN COUNTY AROUND 745 AM. JOHNSON
Special weather statement, Aug 26, 7:35 AM CDT, 8 minutes before
IAZALL-261330- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 735 AM CDT SUN AUG 26 1990 AT 725 AM CDT...AN INTENSE THUNDERSTORM WAS LOCATED OVER NORTH CENTRAL IOWA...BETWEEN CLARION AND BELMOND...OR ABOUT 35 MILES SOUTHWEST OF MASON CITY. THIS THUNDERSTORM ALONG WITH BRIEF VERY HEAVY RAINFALL COULD ALSO PRODUCE SOME HAIL AND BRIEF STRONG GUSTY WIND AS IT MOVES NORTHEAST AT 25 MILES AN HOUR. OVER THE REMAINDER OF NORTH CENTRAL AND CENTRAL IOWA...SCATTERED SHOWERS AND THUNDERSTORMS WERE LOCATED OVER ABOUT A 40 MILE WIDE AREA FROM 15 MILES NORTHEAST OF MASON CITY...TO NEAR EXIRA...OR 60 MILES WEST OF DES MOINES. THESE SHOWERS AND THUNDERSTORMS WERE MOVING NORTHEAST AT 25 MILES AN HOUR. SCATTERED SHOWERS AND THUNDERSTORMS WERE ALSO MOVING RAPIDLY ACROSS THE EXTREME NORTHEAST CORNER OF IOWA. THESE SHOWERS AND STORMS WERE MOVING EAST AT 40 MILES AN HOUR. WPM
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 6:35 AM CDT | Severe Thunderstorm Warning | DMX | Humboldt | 18 min |
| Aug 26, 6:35 AM CDT | Severe Thunderstorm Warning | DMX | Wright | 30 min |
| Aug 26, 7:04 AM CDT | Severe Thunderstorm Warning | DMX | Wright | 31 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 1990Every severe thunderstorm warning in 1990
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.