Alert archive / Minnesota / Red Flag Warnings in 2021

Red Flag Warning 1, NWS Duluth, MN

March 20, 2021Carlton County, Pine County, Saint Louis County, Minnesota

NWS Duluth, MN issued this red flag warning at Mar 20, 2021, 5:37 AM CDT for Carlton County, Pine County, Saint Louis County, Minnesota. It took effect at Mar 20, 2021, 12:00 PM CDT. It was in force for 7 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
Mar 20, 2021, 5:37 AM CDT (10:37 UTC)
In effect from
Mar 20, 2021, 12:00 PM CDT
Expired
Mar 20, 2021, 7:00 PM CDT
In force
7 hr
Issued by
NWS Duluth, MN

Counties Carlton County, MN, Pine County, MN, Saint Louis County, MN

The radar

The Duluth radar (KDLH), 33 km from the middle of the area, began a volume at 10:41 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

International Fa, MN (KINL), launched 00:00Z, 10.6 hours before the alert went out and 207 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, International Fa, MN at 00:00Z on 2021-03-20Temperature 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, International Fa, MN at 00:00Z on 2021-03-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2779 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

938 
WWUS83 KDLH 201037
RFWDLH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Duluth MN
537 AM CDT Sat Mar 20 2021

...LOW RH AND GUSTY WINDS TO LEAD TO CRITICAL FIRE WEATHER 
CONDITIONS SATURDAY...

.An area of very dry air accompanied by gusty winds may lead to
critical fire weather conditions Saturday. Dew points aloft are
near -50C which is very abnormal for an air mass. An inversion
will keep most of this dry air from mixing down, but if a fire
does develop and break the inversion it could rapidly grow.

MNZ011-019-035-036-201145-
/O.CAN.KDLH.FW.A.0001.210320T1700Z-210320T2300Z/
North St. Louis-Central St. Louis-Northern Aitkin-South Aitkin-
537 AM CDT Sat Mar 20 2021

...FIRE WEATHER WATCH IS CANCELLED FOR WIND AND LOW RELATIVE
HUMIDITY FOR PORTIONS OF NORTHERN MINNESOTA...

The National Weather Service in Duluth has cancelled the Fire
Weather Watch.

Fire weather conditions will be near-critical today, with minimum
RH values between 20 and 30 percent along with wind gusts from 30
to 40 mph. The lowest minimum RH values are expected to be in
east-central Minnsota. Areas without snow pack will see the
greatest risk for hazardous fire weather conditions.  

$$

MNZ037-038-201845-
/O.UPG.KDLH.FW.A.0001.210320T1700Z-210320T2300Z/
/O.NEW.KDLH.FW.W.0001.210320T1700Z-210321T0000Z/
Carlton and South St. Louis-Pine-
537 AM CDT Sat Mar 20 2021

...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 7 PM CDT THIS
EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR EAST CENTRAL
MINNESOTA...

The National Weather Service in Duluth has issued a Red Flag
Warning for wind and low relative humidity, which is in effect
from noon today to 7 PM CDT this evening. The Fire Weather Watch
is no longer in effect.

* AFFECTED AREA...In Minnesota, Carlton and South St. Louis and 
  Pine.

* WINDS...South 15 to 20 mph with gusts up to 30 mph.

* RELATIVE HUMIDITY...As low as 24 percent.

* IMPACTS...Rapid fire growth is possible especially with the 
  strong winds and low relative humidities not too far above the 
  surface. If a fire were to break through this inversion, it 
  could exacerbate the spread potential and fire intensities.

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.

&&

$$
2 follow-up statements
439 
WWUS83 KDLH 202139
RFWDLH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Duluth MN
439 PM CDT Sat Mar 20 2021

...NEAR CRITICAL FIRE WEATHER CONDITIONS CONTINUE THIS AFTERNOON...

.Near critical fire weather conditions will continue this
afternoon due to very dry air with relative humidity values around
20 to 25% and winds gusting as high as 30 mph. Conditions will 
improve after sunset this evening.

MNZ037-038-210000-
/O.CON.KDLH.FW.W.0001.000000T0000Z-210321T0000Z/
Carlton and South St. Louis-Pine-
439 PM CDT Sat Mar 20 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR ...

* AFFECTED AREA...In Minnesota, Carlton and South St. Louis and 
  Pine.

* WINDS...South from 15 to 20 mph with gusts up to 30 mph.

* RELATIVE HUMIDITY...As low as 20 percent.

* IMPACTS...Rapid fire growth is possible especially with the 
  strong winds and low relative humidities not too far above the 
  surface. If a fire were to break through this inversion, it 
  could exacerbate the spread potential and fire intensities.

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.

&&

$$
410 
WWUS83 KDLH 210001
RFWDLH

URGENT - FIRE WEATHER MESSAGE
National Weather Service Duluth MN
701 PM CDT Sat Mar 20 2021

MNZ037-038-210115-
/O.EXP.KDLH.FW.W.0001.000000T0000Z-210321T0000Z/
Carlton and South St. Louis-Pine-
701 PM CDT Sat Mar 20 2021

...RED FLAG WARNING HAS EXPIRED..

The humidity will slowly rise this evening and the wind will
remain gusty but be weaker than this afternoon for most areas.

$$

Melde

The office that day

Everything else NWS Duluth, MN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 20, 4:22 AM CDTSmall Craft AdvisoryDLH41 hr

Nearby

Red Flag Warnings in Minnesota, 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.