Alert archive / North Dakota / Mesoscale Discussions in 2008

Mesoscale Discussion 1821

July 20, 200822 counties in North Dakota; Marshall County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2008, 1:52 AM CDT for 22 counties in North Dakota; Marshall County, South Dakota. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Jul 20, 2008, 1:52 AM CDT (06:52 UTC)
Expired
Jul 20, 2008, 3:15 AM CDT
In force
83 min
Issued by
the Storm Prediction Center
All 23 counties

Barnes County, ND, Benson County, ND, Cass County, ND, Dickey County, ND, Eddy County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, LaMoure County, ND, Logan County, ND, Nelson County, ND, Pierce County, ND, Ramsey County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Steele County, ND, Stutsman County, ND, Towner County, ND, Traill County, ND, Walsh County, ND, Wells County, ND, Marshall County, SD

The radar

The Fargo/Grand Forks radar (KMVX), 76 km from the middle of the area, began a volume at 06:56 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

Bismarck Municip, ND (KBIS), launched 00:00Z, 6.9 hours before the alert went out and 193 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 00:00Z on 2008-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 825 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, Bismarck Municip, ND at 00:00Z on 2008-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 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
825 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
1979 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 200652
SWOMCD
SPC MCD 200652 
NDZ000-SDZ000-200815-

MESOSCALE DISCUSSION 1821
NWS STORM PREDICTION CENTER NORMAN OK
0152 AM CDT SUN JUL 20 2008

AREAS AFFECTED...ERN ND

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 200652Z - 200815Z

AN ISOLATED THREAT FOR HAIL WILL LIKELY CONTINUE THROUGH LATE
TONIGHT ACROSS ERN ND. HOWEVER...THE ACTIVITY SHOULD REMAIN TOO
MARGINAL TO WARRANT THE ISSUANCE OF A WW.

LATEST SFC ANALYSIS SHOWS A 1010 MB LOW OVER NRN SD WITH A
STATIONARY FRONT EXTENDING EAST OF THE LOW ACROSS SCNTRL MN. A MOIST
AXIS IS LOCATED JUST EAST OF THE LOW AND THIS IS CONTRIBUTING TO
LOCALIZED MODERATE INSTABILITY WHERE RUC ANALYSIS SUGGESTS MLCAPE
VALUES RANGE FROM 500 TO 1500 J/KG. THIS ALONG WITH STRONG
LARGE-SCALE ASCENT AHEAD OF A SHORTWAVE TROUGH OVER SRN MANITOBA
SHOULD HELP SUSTAIN THE CONVECTION LATE TONIGHT ALTHOUGH A CAPPING
INVERSION SHOULD KEEP THE STORMS ELEVATED IN NATURE. FORECAST
SOUNDINGS THIS EVENING ACROSS THE REGION STRONG VERTICAL SHEAR
PROFILES...500 MB TEMPS IN THE -12 TO -14 C RANGE ALONG WITH STEEP
MID-LEVEL LAPSE RATES SUGGESTING A THREAT FOR ISOLATED HAIL WILL
CONTINUE FOR SEVERAL MORE HOURS.

..BROYLES.. 07/20/2008

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

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

45709749 45729880 46329950 47529980 48360004 48689961
48779878 48659784 48369737 47719706 46959692 46269685

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 19, 8:17 PM CDTMesoscale DiscussionSPCEmmons58 min
Jul 20, 4:45 PM CDTMesoscale DiscussionSPCBennett, Butte, Custer, Fall River, Lawrence, Oglala Lakota and 1 more3 hr
Jul 20, 5:22 PM CDTSevere Thunderstorm WatchSPCBennett, Custer, Fall River, Jackson, Lawrence, Meade and 4 more7 hr

Nearby

Mesoscale Discussions in North Dakota, 2008Mesoscale Discussions in South Dakota, 2008Every mesoscale discussion in 2008

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.