Alert archive / Missouri / Mesoscale Discussions in 2010

Mesoscale Discussion 1821

September 13, 20104 states

The Storm Prediction Center issued this mesoscale discussion at Sep 13, 2010, 5:45 PM CDT for 4 states. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Sep 13, 2010, 5:45 PM CDT (22:45 UTC)
Expired
Sep 13, 2010, 6:45 PM CDT
In force
60 min
Issued by
the Storm Prediction Center
All 26 counties

Adams County, IA, Fremont County, IA, Montgomery County, IA, Page County, IA, Ringgold County, IA, Taylor County, IA, Atchison County, KS, Brown County, KS, Doniphan County, KS, Leavenworth County, KS, Wyandotte County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Clay County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Holt County, MO, Nodaway County, MO, Platte County, MO, Worth County, MO, Nemaha County, NE, Otoe County, NE, Richardson County, NE

The radar

The Pleasant Hill radar (KEAX), 153 km from the middle of the area, began a volume at 22:44 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

Topeka, KS (KTOP), launched 12:00Z, 10.8 hours before the alert went out and 130 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, Topeka, KS at 12:00Z on 2010-09-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1168 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, Topeka, KS at 12:00Z on 2010-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 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
1168 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
594 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

435 
ACUS11 KWNS 132245
SWOMCD
SPC MCD 132245 
MOZ000-IAZ000-KSZ000-NEZ000-132345-

MESOSCALE DISCUSSION 1821
NWS STORM PREDICTION CENTER NORMAN OK
0545 PM CDT MON SEP 13 2010

AREAS AFFECTED...NEB...NRN KS...SWRN IA...NWRN MO

CONCERNING...TORNADO WATCH 656...

VALID 132245Z - 132345Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 656 CONTINUES.

IMMEDIATE CONCERNS ARE FOR THE TRANSITIONING HP SUPERCELL SW OF
OMAHA TURNING INTO A HIGH-WIND SITUATION ACROSS SERN NEB...SWRN
IA...NWRN MO AND NERN KS. THE STORM SHOULD CONTINUE SEWD ALONG THE
INSTABILITY GRADIENT AND ALTHOUGH THE SLY LLJ AXIS WILL DEVELOP
ACROSS CNTRL KS/NEB THIS EVENING...WELL-ORGANIZED NATURE TO THE
STORM WILL LIKELY MAINTAIN SOME DEGREE OF SEVERE THREATS INTO NWRN
MO/NERN KS FOR A FEW MORE HOURS.  AS A RESULT...A NEW WW WILL BE
NEEDED DOWNSTREAM.

..RACY.. 09/13/2010

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

ATTN...WFO...DMX...EAX...OAX...TOP...

LAT...LON   39519538 40619642 40949609 41119453 40679408 40029393
            39239425 38939500 39519538

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 13, 2:38 PM CDTTornado WatchSPCFremont, Mills, Montgomery, Page, Pottawattamie7 hr
Sep 13, 6:09 PM CDTSevere Thunderstorm WatchSPCAdams, Clarke, Decatur, Ringgold, Taylor, Union and 1 more4 hr
Sep 13, 1:38 PM CDTMesoscale DiscussionSPCBrown, Clay, Cloud, Dickinson, Ellsworth, Geary and 18 more67 min
Sep 13, 5:07 PM CDTMesoscale DiscussionSPCBarber, Barton, Clark, Comanche, Edwards, Ellis and 15 more53 min
Sep 13, 6:30 PM CDTMesoscale DiscussionSPCCloud, Decatur, Jewell, Marshall, Norton, Phillips and 3 more60 min

Nearby

Mesoscale Discussions in Missouri, 2010Mesoscale Discussions in Iowa, 2010Mesoscale Discussions in Kansas, 2010Every mesoscale discussion in 2010

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.