Alert archive / Iowa / Red Flag Warnings in 2021

Red Flag Warning 4, NWS Des Moines, IA

April 2, 202135 counties in Iowa

NWS Des Moines, IA issued this red flag warning at Apr 2, 2021, 10:50 AM CDT for 35 counties in Iowa. It took effect at Apr 2, 2021, 11:00 AM CDT. It was in force for 9 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 2, 2021, 10:50 AM CDT (15:50 UTC)
In effect from
Apr 2, 2021, 11:00 AM CDT
Expired
Apr 2, 2021, 8:00 PM CDT
In force
9 hr
Issued by
NWS Des Moines, IA
All 35 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Boone County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Clarke County, IA, Crawford County, IA, Dallas County, IA, Decatur County, IA, Emmet County, IA, Franklin County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Humboldt County, IA, Kossuth County, IA, Madison County, IA, Palo Alto County, IA, Pocahontas County, IA, Polk County, IA, Ringgold County, IA, Sac County, IA, Story County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Webster County, IA, Winnebago County, IA, Worth County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 54 km from the middle of the area, began a volume at 15:54 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 12:00Z, 3.8 hours before the alert went out and 202 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 12:00Z on 2021-04-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2021-04-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 840 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2259 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
840 m²/s²
0-3 km storm-relative helicity
1056 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

490 
WWUS83 KDMX 021550
RFWDMX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Des Moines IA
1050 AM CDT Fri Apr 2 2021

...Elevated Fire Danger Today...

.Strong south winds of 25 to 35 mph with higher gusts over 40 mph
possible along with very low humidity values and dry or dead
vegetation has led to the potential for elevated fire danger
today. Burning is not recommended.

IAZ004>007-015>017-023>026-033>037-044>048-057>060-070>073-
081>083-092>094-030000-
/O.NEW.KDMX.FW.W.0004.210402T1600Z-210403T0100Z/
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Pocahontas-Humboldt-Wright-Franklin-Sac-Calhoun-Webster-Hamilton-
Hardin-Crawford-Carroll-Greene-Boone-Story-Audubon-Guthrie-Dallas-
Polk-Cass-Adair-Madison-Warren-Adams-Union-Clarke-Taylor-Ringgold-
Decatur-
1050 AM CDT Fri Apr 2 2021

...RED FLAG WARNING IN EFFECT UNTIL 8 PM CDT THIS EVENING FOR
EXTREME FIRE CONDITIONS....

The National Weather Service in Des Moines has issued a Red Flag
Warning FOR EXTREME FIRE CONDITIONS, which is in effect until
8 PM CDT this evening.

* Relative Humidity...As low as 21 percent.

* Impacts...Any fires that develop today may spread rapidly and 
  become uncontrollable. 

* WIND...Strong south winds with sustained speeds of 25 to 35 mph,
  with gusts as high as 45 mph possible. The strongest wind gusts
  are likely to occur in western portions of Iowa. 

* FUEL...Prairie grasses and other vegetation remains dry or dead
  and will easily ignite. Plus, any lingering crop debris could
  quickly burn in these conditions. The combination of all the
  aforementioned aspects will lead to extremely fast fire growth.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

&&

$$

Podrazik/Martin
2 follow-up statements
971 
WWUS83 KDMX 022023
RFWDMX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Des Moines IA
323 PM CDT Fri Apr 2 2021

...Elevated Fire Danger Through This Evening...

.The very strong south winds of 25 to 35 mph with higher gusts 
over 40 mph look to persist through the evening hours. In addition
to the intense winds, humidity values remain low and the
vegetation continues to be susceptible to burning leading to the 
potential for elevated fire danger today. Burning is not 
recommended.

IAZ004>007-015>017-023>026-033>037-044>048-057>060-070>073-
081>083-092>094-030100-
/O.CON.KDMX.FW.W.0004.000000T0000Z-210403T0100Z/
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Pocahontas-Humboldt-Wright-Franklin-Sac-Calhoun-Webster-Hamilton-
Hardin-Crawford-Carroll-Greene-Boone-Story-Audubon-Guthrie-Dallas-
Polk-Cass-Adair-Madison-Warren-Adams-Union-Clarke-Taylor-Ringgold-
Decatur-
323 PM CDT Fri Apr 2 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM CDT THIS EVENING
FOR EXTREME FIRE CONDITIONS....

* Relative Humidity...As low as 21 percent.

* Impacts...Any fires that develop today may spread rapidly and 
  become uncontrollable.

* WIND...Strong south winds with sustained speeds of 25 to 35 
  mph, with gusts as high as 45 mph possible. The strongest wind 
  gusts are likely to occur in western portions of Iowa.

* FUEL...Prairie grasses and other vegetation remains dry or 
  dead and will easily ignite. Plus, any lingering crop debris 
  could quickly burn in these conditions. The combination of all 
  the aforementioned aspects will lead to extremely fast fire 
  growth.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity, and warm temperatures can
contribute to extreme fire behavior.

&&

$$

KLP
413 
WWUS83 KDMX 030056
RFWDMX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Des Moines IA
756 PM CDT Fri Apr 2 2021

IAZ004>007-015>017-023>026-033>037-044>048-057>060-070>073-
081>083-092>094-030200-
/O.EXP.KDMX.FW.W.0004.000000T0000Z-210403T0100Z/
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Pocahontas-Humboldt-Wright-Franklin-Sac-Calhoun-Webster-Hamilton-
Hardin-Crawford-Carroll-Greene-Boone-Story-Audubon-Guthrie-Dallas-
Polk-Cass-Adair-Madison-Warren-Adams-Union-Clarke-Taylor-Ringgold-
Decatur-
756 PM CDT Fri Apr 2 2021

...RED FLAG WARNING WILL EXPIRE AT 8 PM CDT THIS EVENING FOR
EXTREME FIRE CONDITIONS....

Strong winds, warm temperatures, and dry conditions that combined
to produce Red Flag Warning criteria have eased. Therefore the 
red flag warning will be allowed to expire at 8 PM.

$$

Zogg

Nearby

Red Flag Warnings in Iowa, 2021Every red flag warning 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.