Alert archive / Iowa / Special Weather Statements in 2021

Special Weather Statement, NWS Des Moines, IA

August 8, 2021Greene County, Iowa

NWS Des Moines, IA issued this special weather statement at Aug 8, 2021, 12:45 AM CDT for Greene County, Iowa. It was in force for 30 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
Aug 8, 2021, 12:45 AM CDT (05:45 UTC)
Expired
Aug 8, 2021, 1:15 AM CDT
In force
30 min
Issued by
NWS Des Moines, IA
Hail
0.00 in
Wind
40

County Greene County, IA

The radar

The Des Moines radar (KDMX), 58 km from the middle of the area, began a volume at 05:48 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

Omaha, NE (KOAX), launched 00:00Z, 5.8 hours before the alert went out and 188 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, Omaha, NE at 00:00Z on 2021-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2933 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2021-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 149 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
2933 J/kg
Mixed-layer CIN
-124 J/kg
Mixed-layer LCL
1327 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
149 m²/s²
0-3 km storm-relative helicity
195 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.3

Open this sounding in Storm Lab

The text

As transmitted.

087 
WWUS83 KDMX 080545
SPSDMX

Special Weather Statement
National Weather Service Des Moines IA
1245 AM CDT Sun Aug 8 2021
 
IAZ046-047-080615-
Boone IA-Greene IA-
1245 AM CDT Sun Aug 8 2021

...A strong thunderstorm will impact portions of east central Greene
and west central Boone Counties through 115 AM CDT...

At 1244 AM CDT, Doppler radar was tracking a strong thunderstorm near
Jefferson, moving northeast at 25 mph.

HAZARD...Winds in excess of 40 mph. Recently, the Jefferson Airport 
         had a wind gust to 36 mph with a personal weather station 
         south of Jefferson gusting to 43 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects.

This storm will remain over mainly rural areas of west central Boone
and east central Greene Counties, including the following
locations... Dana, Beaver, Grand Junction and Jefferson Municipal
Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

&&

LAT...LON 4195 9440 4204 9445 4217 9416 4198 9410
TIME...MOT...LOC 0544Z 242DEG 22KT 4200 9431 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

$$

Ansorge

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 8, 12:03 AM CDTSpecial Weather StatementDMXAdams, Taylor57 min
Aug 8, 12:26 AM CDTSpecial Weather StatementDMXGreene49 min
Aug 8, 12:51 AM CDTSpecial Weather StatementDMXDecatur, Ringgold, Union54 min
Aug 8, 1:20 AM CDTSpecial Weather StatementDMXTama55 min
Aug 8, 1:29 AM CDTSpecial Weather StatementDMXClarke, Decatur, Lucas, Wayne46 min
Aug 8, 1:41 AM CDTSpecial Weather StatementDMXStory49 min
Aug 8, 2:03 AM CDTSpecial Weather StatementDMXGrundy, Hardin42 min
Aug 8, 2:24 AM CDTSpecial Weather StatementDMXBlack Hawk51 min
Aug 8, 3:11 AM CDTSpecial Weather StatementDMXBlack Hawk64 min
Aug 8, 3:39 PM CDTHeat AdvisoryDMXAdair, Adams, Appanoose, Black Hawk, Boone, Bremer and 26 more51 hr

Nearby

Special Weather Statements in Iowa, 2021Every special weather statement in 2021

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.