Alert archive / Missouri / Mesoscale Discussions in 2019

Mesoscale Discussion 729

May 21, 2019Saint Charles County, Saint Louis County, City of Saint Louis, Missouri

The Storm Prediction Center issued this mesoscale discussion at May 21, 2019, 6:12 PM CDT for Saint Charles County, Saint Louis County, City of Saint Louis, Missouri. It was in force for 33 min.

The area

The outline as issued.

The facts

Issued
May 21, 2019, 6:12 PM CDT (23:12 UTC)
Expired
May 21, 2019, 6:45 PM CDT
In force
33 min
Issued by
the Storm Prediction Center

Counties City of Saint Louis, MO, Saint Charles County, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 9 km from the middle of the area, began a volume at 23:11 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

Lincoln, IL (KILX), launched 12:00Z, 11.2 hours before the alert went out and 234 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, Lincoln, IL at 12:00Z on 2019-05-21Temperature 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, Lincoln, IL at 12:00Z on 2019-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 331 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
1157 m above ground
0-6 km bulk shear
76 kt
0-1 km storm-relative helicity
331 m²/s²
0-3 km storm-relative helicity
917 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 8:20 PM CDTSevere Thunderstorm WatchSPCBenton, Camden, Dent, Hickory, Howell, Laclede and 10 more8 hr
May 20, 10:30 PM CDTMesoscale DiscussionSPCBarry, Christian, Dade, Dallas, Douglas, Greene and 11 more60 min
May 20, 11:06 PM CDTMesoscale DiscussionSPCMcDonald24 min
May 21, 12:18 AM CDTTornado WatchSPCBarry, Christian, Douglas, Howell, McDonald, Ozark and 4 more5 hr
May 21, 12:55 AM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Carter, Crawford, Dent and 26 more95 min
May 21, 9:57 AM CDTMesoscale DiscussionSPCCamden, Christian, Dallas, Douglas, Greene, Hickory and 10 more93 min
May 21, 11:32 AM CDTTornado WatchSPCBarry, Camden, Christian, Dallas, Dent, Douglas and 16 more7 hr
May 21, 1:51 PM CDTMesoscale DiscussionSPCCamden, Dent, Douglas, Laclede, Maries, Ozark and 6 more84 min
May 21, 3:10 PM CDTTornado WatchSPCAudrain, Bollinger, Boone, Butler, Callaway, Cape Girardeau and 32 more8 hr
May 21, 4:43 PM CDTMesoscale DiscussionSPCDunklin, Pemiscot62 min
May 21, 5:43 PM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Carter, Crawford, Franklin and 20 more62 min
May 21, 6:53 PM CDTSevere Thunderstorm WatchSPCAtchison, Holt3 hr

Nearby

Mesoscale Discussions in Missouri, 2019Every mesoscale discussion in 2019

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.