Alert archive / Iowa / Special Weather Statements in 2020
Special Weather Statement, NWS La Crosse, WI
NWS La Crosse, WI issued this special weather statement at Jul 18, 2020, 7:37 AM CDT for Chickasaw County, Howard County, Winneshiek County, Iowa. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jul 18, 2020, 7:37 AM CDT (12:37 UTC)
- Expired
- Jul 18, 2020, 8:15 AM CDT
- In force
- 38 min
- Issued by
- NWS La Crosse, WI
Counties Chickasaw County, IA, Howard County, IA, Winneshiek County, IA
The radar
The La Crosse radar (KARX), 87 km from the middle of the area, began a volume at 12:42 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
Davenport, (KDVN), launched 12:00Z, 0.6 hours before the alert went out and 212 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
- 1268 J/kg
- Mixed-layer CIN
- -157 J/kg
- Mixed-layer LCL
- 1158 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 70 m²/s²
- 0-3 km storm-relative helicity
- 92 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.7
The text
As transmitted.
342
WWUS83 KARX 181237
SPSARX
Special Weather Statement
National Weather Service La Crosse WI
737 AM CDT Sat Jul 18 2020
IAZ009>011-019-029-181315-
Winneshiek-Chickasaw-Howard-Fayette-Allamakee-
737 AM CDT Sat Jul 18 2020
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT HOWARD...NORTHERN
FAYETTE...WESTERN ALLAMAKEE...WINNESHIEK AND CHICKASAW COUNTIES...
At 737 AM CDT, radar indicated strong thunderstorms were located
along a line extending from near Canton to New Hampton. Movement was
east at 45 mph.
Winds in excess of 40 mph and pea size hail are possible with these
storms.
Locations impacted include...
Decorah, Waukon, Cresco, New Hampton, West Union, Postville, Calmar,
Fredericksburg, Ossian, Elgin, Clermont, Lime Springs, Lawler,
Spillville, Fort Atkinson, Ridgeway, Ionia, Protivin, Waucoma and
Jerico.
If outdoors, seek shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
LAT...LON 4350 9230 4350 9133 4308 9158 4308 9161
4294 9161 4299 9254
TIME...MOT...LOC 1237Z 279DEG 39KT 4347 9193 4309 9232
$$
NMBThe office that day
Everything else NWS La Crosse, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 18, 3:10 AM CDT | Special Weather Statement | ARX | Clark, Taylor | 65 min |
| Jul 18, 3:49 AM CDT | Special Weather Statement | ARX | Buffalo, Taylor | 56 min |
| Jul 18, 4:35 AM CDT | Special Weather Statement | ARX | Buffalo, Clark, Taylor, Trempealeau | 55 min |
| Jul 18, 5:03 AM CDT | Special Weather Statement | ARX | Jackson, La Crosse | 42 min |
| Jul 18, 5:46 AM CDT | Special Weather Statement | ARX | La Crosse, Monroe | 29 min |
| Jul 18, 6:14 AM CDT | Special Weather Statement | ARX | Adams, Crawford, Juneau, Vernon | 61 min |
| Jul 18, 8:57 AM CDT | Special Weather Statement | ARX | Crawford, Grant, Richland | 63 min |
| Jul 18, 9:57 AM CDT | Special Weather Statement | ARX | Grant | 33 min |
| Jul 18, 7:03 AM CDT | Special Weather Statement | ARX | Chickasaw, Floyd, Howard, Mitchell | 42 min |
| Jul 18, 8:15 AM CDT | Special Weather Statement | ARX | Allamakee, Fayette, Winneshiek | 60 min |
| Jul 18, 6:01 AM CDT | Special Weather Statement | ARX | Dodge, Mower | 44 min |
| Jul 18, 6:44 AM CDT | Special Weather Statement | ARX | Fillmore, Olmsted | 46 min |
| Jul 18, 7:27 AM CDT | Special Weather Statement | ARX | Fillmore, Houston | 48 min |
Nearby
Special Weather Statements in Iowa, 2020Every special weather statement in 2020
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.