Alert archive / North Dakota / Mesoscale Discussions in 2014

Mesoscale Discussion 1421

July 21, 201411 counties in Minnesota; 35 counties in North Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 21, 2014, 4:01 PM CDT for 11 counties in Minnesota; 35 counties in North Dakota. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Jul 21, 2014, 4:01 PM CDT (21:01 UTC)
Expired
Jul 21, 2014, 5:30 PM CDT
In force
89 min
Issued by
the Storm Prediction Center
All 46 counties

Becker County, MN, Clay County, MN, Clearwater County, MN, Kittson County, MN, Mahnomen County, MN, Marshall County, MN, Norman County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Roseau County, MN, Barnes County, ND, Benson County, ND, Burleigh County, ND, Cass County, ND, Cavalier County, ND, Dickey County, ND, Eddy County, ND, Emmons County, ND, Foster County, ND, Grand Forks County, ND, Grant County, ND, Griggs County, ND, Kidder County, ND, LaMoure County, ND, Logan County, ND, McHenry County, ND, McIntosh County, ND, McLean County, ND, Mercer County, ND, Morton County, ND, Nelson County, ND, Oliver County, ND, Pembina County, ND, Pierce County, ND, Ramsey County, ND, Ransom County, ND, Sheridan County, ND, Sioux County, ND, Steele County, ND, Stutsman County, ND, Towner County, ND, Traill County, ND, Walsh County, ND, Ward County, ND, Wells County, ND

The radar

The Bismarck radar (KBIS), 132 km from the middle of the area, began a volume at 21:04 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

Bismarck Municip, ND (KBIS), launched 12:00Z, 9.0 hours before the alert went out and 128 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, Bismarck Municip, ND at 12:00Z on 2014-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3163 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, Bismarck Municip, ND at 12:00Z on 2014-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 98 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
3163 J/kg
Mixed-layer CIN
-177 J/kg
Mixed-layer LCL
1523 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
98 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

310 
ACUS11 KWNS 212102
SWOMCD
SPC MCD 212101 
MNZ000-NDZ000-212230-

MESOSCALE DISCUSSION 1421
NWS STORM PREDICTION CENTER NORMAN OK
0401 PM CDT MON JUL 21 2014

AREAS AFFECTED...ND AND NORTHERN MN

CONCERNING...TORNADO WATCH 426...

VALID 212101Z - 212230Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 426 CONTINUES.

SUMMARY...LARGE HAIL/SOME TORNADO RISK WILL CONTINUE THIS
AFTERNOON ACROSS SOUTHWEST/CENTRAL ND...HOWEVER THE POTENTIAL FOR
WIDESPREAD/INTENSE DAMAGING WINDS /POSSIBLE DERECHO/ IS OTHERWISE
EXPECTED TO STEADILY INCREASE THROUGH LATE AFTERNOON/EARLY EVENING
ACROSS ND INTO NORTHERN MN. TORNADO WATCH 426 CONTINUES ACROSS ND
UNTIL 00Z. CURRENT THINKING IS THAT AN ADDITIONAL WATCH IS HIGHLY
LIKELY ACROSS EASTERN ND/NORTHERN MN BY EARLY EVENING...WITH
ISSUANCE POTENTIALLY AS EARLY AS 22-23Z.

DISCUSSION...A SURFACE BOUNDARY CONTINUES TO ANGLE GENERALLY
SOUTHWEST-NORTHEASTWARD ACROSS ND AT MID-AFTERNOON...WITH A VERY
MOIST/UNSTABLE AIR MASS LOCATED NEAR/SOUTH OF THE SURFACE FRONT.
NEAR THIS BOUNDARY...AN INCREASINGLY WELL-ORGANIZED QUASI-LINEAR
COMPLEX CONTINUES TO EVOLVE AS OF 2045Z...WITH A STRONG SOUTH-END
SUPERCELL NEAR I-94 EAST OF THE DICKINSON AREA. A LARGE HAIL/TORNADO
RISK IS POSSIBLE WITH THIS STORM...AND ANY OTHER SEMI-DISCRETE
SUPERCELLULAR DEVELOPMENT NEAR THE SURFACE BOUNDARY ACROSS
CENTRAL/NORTHEAST ND.

THAT SAID...CURRENT TRENDS SUGGEST THAT THE DEVELOPMENT/MATURATION
OF A SPATIALLY EXPANDING QUASI-LINEAR MESOSCALE CONVECTIVE SYSTEM
WILL LIKELY BE THE PREVALENT SCENARIO INTO THIS EVENING...ESPECIALLY
IN VICINITY OF THE AFOREMENTIONED SURFACE BOUNDARY ACROSS ND. AS
THIS MCS CONTINUES TO GROW UPSCALE AND GRADUALLY ACCELERATE
EAST-NORTHEASTWARD /POTENTIALLY REACHING 50 KT FORWARD
MOTION/...WIDESPREAD/POTENTIALLY INTENSE DAMAGING WINDS SHOULD
BECOME AN INCREASING CONCERN THROUGH LATE AFTERNOON ACROSS
CENTRAL/EASTERN ND. THIS MCS WILL THRIVE WITHIN AN ENVIRONMENT THAT
IS CHARACTERIZED BY STRONG TO EXTREME INSTABILITY...WITH 18Z
OBSERVED REGIONAL SOUNDINGS/20Z SPC OBJECTIVE ANALYSIS SUPPORTIVE OF
2500-5000 J/KG MLCAPE ACROSS CENTRAL/EASTERN ND.

..GUYER.. 07/21/2014

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

ATTN...WFO...FGF...BIS...

LAT...LON   46910227 48360152 49009816 48789500 47059508 46109803
            46110200 46910227

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 5:07 PM CDTSevere Thunderstorm WatchSPCBig Stone, Clay, Kittson, Mahnomen, Marshall, Norman and 6 more6 hr
Jul 21, 12:52 PM CDTMesoscale DiscussionSPCAdams, Benson, Billings, Burleigh, Dunn, Grant and 16 more83 min
Jul 21, 1:09 PM CDTTornado WatchSPCAdams, Benson, Billings, Bottineau, Bowman, Burke and 33 more6 hr
Jul 21, 3:20 PM CDTMesoscale DiscussionSPCAdams, Benson, Burleigh, Dunn, Eddy, Emmons and 20 more55 min
Jul 21, 6:42 PM CDTMesoscale DiscussionSPCBarnes, Benson, Cass, Cavalier, Dickey, Eddy and 18 more93 min

Nearby

Mesoscale Discussions in North Dakota, 2014Mesoscale Discussions in Minnesota, 2014Every mesoscale discussion in 2014

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.