Alert archive / Missouri / Mesoscale Discussions in 2016

Mesoscale Discussion 475

April 27, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2016, 1:58 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 27, 2016, 1:58 PM CDT (18:58 UTC)
Expired
Apr 27, 2016, 4:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 52 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Cass County, IA, Clarke County, IA, Davis County, IA, Decatur County, IA, Fremont County, IA, Lucas County, IA, Madison County, IA, Mills County, IA, Monroe County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Ringgold County, IA, Taylor County, IA, Union County, IA, Wayne County, IA, Atchison County, KS, Brown County, KS, Doniphan County, KS, Jefferson County, KS, Leavenworth County, KS, Adair County, MO, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Caldwell County, MO, Clay County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Linn County, MO, Livingston County, MO, Mercer County, MO, Nodaway County, MO, Platte County, MO, Putnam County, MO, Schuyler County, MO, Sullivan County, MO, Worth County, MO, Cass County, NE, Douglas County, NE, Nemaha County, NE, Otoe County, NE, Sarpy County, NE, Washington County, NE

The radar

The Omaha radar (KOAX), 138 km from the middle of the area, began a volume at 19:02 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

Omaha, NE (KOAX), launched 12:00Z, 7.0 hours before the alert went out and 138 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, Omaha, NE at 12:00Z on 2016-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Omaha, NE at 12:00Z on 2016-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 268 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
514 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
268 m²/s²
0-3 km storm-relative helicity
345 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

609 
ACUS11 KWNS 271859
SWOMCD
SPC MCD 271858 
MOZ000-IAZ000-KSZ000-NEZ000-272100-

MESOSCALE DISCUSSION 0475
NWS STORM PREDICTION CENTER NORMAN OK
0158 PM CDT WED APR 27 2016

AREAS AFFECTED...NORTHEAST KS/NORTHWEST AND PART OF NORTHERN
MO/SOUTHERN IA AND A SMALL PART OF EASTERN NEB

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 271858Z - 272100Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...ONE OR MORE BROKEN LINES OF STORMS ARE EXPECTED TO DEVELOP
AND INCREASE SOME IN INTENSITY THIS AFTERNOON FROM NORTHEAST KS AND
FAR SOUTHEAST NEB INTO NORTHWEST MO...AND SPREADING INTO MUCH OF THE
REST OF NORTHERN MO...SOUTHERN IA...AND EASTERN NEB.  SEVERE-CALIBER
HAIL AND LOCALLY STRONG WIND GUSTS SHOULD BE THE PRIMARY THREATS. 
THE POTENTIAL FOR A TORNADO THREAT APPEARS TO BE GREATEST ACROSS
SOUTHERN IA AND NORTHEAST MO LATER THIS AFTERNOON INTO THE EARLY
EVENING.

DISCUSSION...EARLY AFTERNOON SURFACE ANALYSIS SHOWED A 994-MB LOW
PRESSURE AREA IN EASTERN NEB WITH A WARM FRONT EXTENDING TO THE
SOUTHEAST THROUGH EXTREME SOUTHWEST IA INTO NORTHEAST MO AND
SOUTHERN IL...WHILE DRY LINE/COLD FRONT EXTENDED SOUTHWARD THROUGH
SOUTHEAST NEB AND EASTERN NEB.  A SECOND COLD FRONT EXTENDED TO THE
SOUTH/SOUTHWEST THROUGH CENTRAL KS AND CENTRAL OK.

MOSAIC RADAR IMAGERY SHOWED TSTMS HAD DEVELOPED ACROSS NORTHEAST KS
AND EAST-CENTRAL NEB ALONG THE DRY LINE/COLD FRONT AND THE
INTERSECTION OF THE WARM FRONT/DRY LINE...RESPECTIVELY.  COLD
MIDLEVEL TEMPERATURES AND FORCING FOR ASCENT ATTENDANT TO THE
CENTRAL PLAINS CLOSED LOW/TROUGH ARE SPREADING NORTHEAST ACROSS THE
MOIST AND MODERATELY UNSTABLE CORRIDOR EXTENDING NORTHWARD THROUGH
THE WARM SECTOR.  EFFECTIVE BULK SHEAR HAS STRENGTHENED TO SUPPORT
ORGANIZED STORMS...WHILE LOW-LEVEL SHEAR IS EXPECTED TO BE GREATEST
IN VICINITY OF THE WARM FRONT...ENHANCING AN ISOLATED TORNADO
THREAT.

..PETERS/CORFIDI.. 04/27/2016

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

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

LAT...LON   41629620 41649539 41259329 40859228 40089243 39429382
            39209447 39139547 39779559 40289575 40879644 41069658
            41439665 41629620

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 27, 2:33 PM CDTTornado WatchSPCAdair, Adams, Appanoose, Cass, Clarke, Decatur and 12 more7 hr
Apr 27, 5:34 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Cass, Clarke, Davis and 12 more116 min
Apr 26, 8:17 PM CDTMesoscale DiscussionSPCAllen, Anderson, Bourbon, Butler, Chase, Chautauqua and 42 more28 min
Apr 26, 8:50 PM CDTSevere Thunderstorm WatchSPCAllen, Anderson, Bourbon, Butler, Chautauqua, Cherokee and 17 more7 hr
Apr 26, 9:36 PM CDTMesoscale DiscussionSPCMcDonald114 min
Apr 27, 12:40 AM CDTMesoscale DiscussionSPCBarry, Benton, Camden, Cedar, Christian, Dade and 26 more95 min

Nearby

Mesoscale Discussions in Missouri, 2016Mesoscale Discussions in Iowa, 2016Mesoscale Discussions in Nebraska, 2016Every mesoscale discussion in 2016

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.