Alert archive / Minnesota / Mesoscale Discussions in 2021

Mesoscale Discussion 701

May 22, 2021Cook County, Lake County, Saint Louis County, Minnesota

The Storm Prediction Center issued this mesoscale discussion at May 22, 2021, 1:22 PM CDT for Cook County, Lake County, Saint Louis County, Minnesota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 22, 2021, 1:22 PM CDT (18:22 UTC)
Expired
May 22, 2021, 3:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%

Counties Cook County, MN, Lake County, MN, Saint Louis County, MN

The radar

The Duluth radar (KDLH), 111 km from the middle of the area, began a volume at 18:23 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 12:00Z, 6.4 hours before the alert went out and 164 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 12:00Z on 2021-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 500 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, International Fa, MN at 12:00Z on 2021-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 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
500 J/kg
Mixed-layer CIN
-125 J/kg
Mixed-layer LCL
1008 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted.

316 
ACUS11 KWNS 221823
SWOMCD
SPC MCD 221822 
MNZ000-222045-

Mesoscale Discussion 0701
NWS Storm Prediction Center Norman OK
0122 PM CDT Sat May 22 2021

Areas affected...the Arrowhead of Minnesota

Concerning...Severe potential...Watch unlikely 

Valid 221822Z - 222045Z

Probability of Watch Issuance...5 percent

SUMMARY...Isolated storms producing marginal hail or wind are
possible after 20Z.

DISCUSSION...Visible imagery and surface observations indicate good
heating continues ahead of a cold front into the Arrowhead, with
temperatures around 80 F. CU continued to increase within the moist
air mass, with MLCAPE to around 1000 J/kg. Though unstable, capping
is currently suppressing development as of 18Z.

Temperatures are expected to warm a few degrees more this afternoon
as the cold front continues slowly east. Lift along the front should
prime the moist boundary layer enough to break the cap, with
isolated storms expected. Modest deep-layer shear and midlevel lapse
rates may favor marginal hail in the strongest storms, along with
gusty winds. Overall coverage of storms and marginal nature of the
severe threat suggest a watch is unlikely.

..Jewell/Guyer.. 05/22/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DLH...

LAT...LON   47998949 47768987 47609063 47239121 47029155 46899180
            46769213 46879267 47039314 47459350 47899346 48269315
            48629259 48419197 48189140 48329089 48199008 48068965
            47998949

Nearby

Mesoscale Discussions in Minnesota, 2021Every mesoscale discussion 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.