Alert archive / Minnesota / Mesoscale Discussions in 2004

Mesoscale Discussion 486

April 28, 200419 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2004, 2:35 PM CDT for 19 counties in Minnesota. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Apr 28, 2004, 2:35 PM CDT (19:35 UTC)
Expired
Apr 28, 2004, 4:00 PM CDT
In force
85 min
Issued by
the Storm Prediction Center

Counties Aitkin County, MN, Benton County, MN, Carlton County, MN, Cass County, MN, Crow Wing County, MN, Douglas County, MN, Grant County, MN, Hubbard County, MN, Itasca County, MN, Kanabec County, MN, Mille Lacs County, MN, Morrison County, MN, Otter Tail County, MN, Pine County, MN, Pope County, MN, Stearns County, MN, Stevens County, MN, Todd County, MN, Wadena County, MN

The radar

The Duluth radar (KDLH), 177 km from the middle of the area, began a volume at 19:35 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 7.6 hours before the alert went out and 197 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, Minneapolis, MN at 12:00Z on 2004-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Minneapolis, MN at 12:00Z on 2004-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 442 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
2 J/kg
Mixed-layer CIN
-770 J/kg
Mixed-layer LCL
1710 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
442 m²/s²
0-3 km storm-relative helicity
431 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

090 
ACUS11 KWNS 281935
SWOMCD
SPC MCD 281935 
MNZ000-282100-

MESOSCALE DISCUSSION 0486
NWS STORM PREDICTION CENTER NORMAN OK
0235 PM CDT WED APR 28 2004

AREAS AFFECTED...W-CNTRL INTO NERN MN

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 281935Z - 282100Z

TSTM POTENTIAL APPEARS TO BE INCREASING AND REGION WILL BE UPGRADED
TO A SLIGHT RISK AT 20Z.

AS OF 1930Z...VISIBLE SATELLITE IMAGERY INDICATED A TOWERING CUMULUS
FIELD DEVELOPING OVER GRANT...STEVENS AND POPE COUNTIES IN W-CNTRL
MN. LATEST MESOANALYSIS SUGGESTS THAT THIS DEVELOPMENT IS OCCURRING
IN A ZONE OF SUSTAINED LOW-LEVEL CONVERGENCE E OF A SURFACE LOW AND
ATTENDANT PRE-FRONTAL TROUGH THAT WAS LOCATED W OF AXN AS OF 19Z.
HERE TEMPERATURES HAVE WARMED THROUGH THE 80S...CONTRIBUTING TO A
DEEPLY MIXED BOUNDARY LAYER WHICH IS OVERCOMING CONSIDERABLE CAP
OBSERVED ON 12Z SOUNDINGS. MODIFICATION OF PROXIMITY RUC SOUNDINGS
FOR CURRENT SURFACE CONDITIONS YIELDS MLCAPES OF 1000-1500 J/KG
WITHIN MODERATELY SHEARED ENVIRONMENT.

IF TSTMS CAN DEVELOP AND BECOME SUSTAINED....DEEPLY MIXED CHARACTER
OF BOUNDARY-LAYER SUGGESTS THAT DAMAGING DOWNBURSTS WILL BE PRIMARY
SEVERE WEATHER THREAT. MARGINALLY SEVERE HAIL MAY ACCOMPANY
STRONGEST STORMS AS WELL.

AREA WILL BE UPGRADED TO SLIGHT RISK AT 20Z AND CONVECTIVE TRENDS
WILL BE MONITORED FOR POSSIBLE WW.

..MEAD.. 04/28/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...DLH...MPX...FGF...

46029625 47099529 48049405 47819271 46869247 46099268
45319463 45329601

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 28, 3:25 PM CDTSevere Thunderstorm WatchSPCAitkin, Carlton, Cass, Crow Wing, Hubbard, Itasca and 5 more6 hr
Apr 28, 6:01 PM CDTMesoscale DiscussionSPCAitkin, Benton, Carlton, Crow Wing, Kanabec, Lake and 5 more89 min

Nearby

Mesoscale Discussions in Minnesota, 2004Every mesoscale discussion in 2004

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.