Alert archive / Arkansas / Mesoscale Discussions in 2017

Mesoscale Discussion 856

May 27, 201716 counties in Arkansas; 10 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 27, 2017, 2:04 AM CDT for 16 counties in Arkansas; 10 counties in Missouri. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
May 27, 2017, 2:04 AM CDT (07:04 UTC)
Expired
May 27, 2017, 4:00 AM CDT
In force
116 min
Issued by
the Storm Prediction Center
All 26 counties

Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Fulton County, AR, Independence County, AR, Izard County, AR, Lawrence County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Washington County, AR, Barry County, MO, Christian County, MO, Douglas County, MO, Howell County, MO, McDonald County, MO, Oregon County, MO, Ozark County, MO, Shannon County, MO, Stone County, MO, Taney County, MO

The radar

The Springfield radar (KSGF), 102 km from the middle of the area, began a volume at 07:04 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

Springfield, MO (KSGF), launched 00:00Z, 7.1 hours before the alert went out and 87 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, Springfield, MO at 00:00Z on 2017-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2596 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, Springfield, MO at 00:00Z on 2017-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 square meters per square second.1939587897Sfc1 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
2596 J/kg
Mixed-layer CIN
-56 J/kg
Mixed-layer LCL
942 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
1.4
Supercell composite
6.5

Open this sounding in Storm Lab

The text

As transmitted.

011 
ACUS11 KWNS 270704
SWOMCD
SPC MCD 270704 
ARZ000-MOZ000-OKZ000-270900-

Mesoscale Discussion 0856
NWS Storm Prediction Center Norman OK
0204 AM CDT Sat May 27 2017

Areas affected...Portions of northern Arkansas and southern Missouri

Concerning...Severe Thunderstorm Watch 272...

Valid 270704Z - 270900Z

The severe weather threat for Severe Thunderstorm Watch 272
continues.

SUMMARY...A small cluster of strong/locally severe storms continues
across the Ozarks vicinity, where large hail and locally damaging
winds remain possible.

DISCUSSION...Latest radar loop shows a small cluster of strong
storms crossing parts of southwest MO and adjacent northern AR, with
the strongest cell -- a severe storm which has recently produced 2"
hail -- now crossing Boone County AR just south of the MO/AR border.

The storms are ongoing within a favorable thermodynamic environment,
near the nose of a subtle 30 to 35 kt low-level jet per recent VWP
data from area radars.  Surface analysis reveals a weak mesolow over
northeast OK, with a mesoscale warm front extending east-northeast
into northwest AR/southwest MO -- i.e. across the region where
storms are ongoing.  With this boundary -- and the aforementioned
low-level jet -- providing a source of low-level ascent, and with
the kinematic and thermodynamic environment supportive of
organized/rotating updrafts, local severe risk will likely continue
across this area over the next several hours.

..Goss.. 05/27/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...PAH...MEG...LZK...SGF...TSA...

LAT...LON   35779453 36049468 36619446 36929404 37119243 37259117
            36049058 35639154 35779453

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 10:36 PM CDTMesoscale DiscussionSPCBenton, Crawford, Madison, Washington54 min
May 27, 12:06 AM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Fulton, Izard and 7 more5 hr
May 27, 3:54 AM CDTMesoscale DiscussionSPCBaxter, Boone, Clay, Craighead, Fulton, Greene and 7 more2 hr
May 27, 4:19 AM CDTSevere Thunderstorm WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lawrence and 3 more6 hr
May 27, 6:12 AM CDTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Mississippi and 1 more2 hr
May 27, 4:01 PM CDTTornado WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more10 hr
May 27, 6:17 PM CDTMesoscale DiscussionSPCBaxter, Boone, Cleburne, Craighead, Fulton, Greene and 12 more58 min
May 27, 9:59 AM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Boone, Callaway, Camden and 47 more2 hr
May 27, 12:13 PM CDTTornado WatchSPCBarry, Barton, Bates, Benton, Bollinger, Boone and 61 more7 hr
May 27, 1:12 PM CDTMesoscale DiscussionSPCBarry, Barton, Bates, Benton, Bollinger, Camden and 50 more93 min
May 27, 1:16 PM CDTMesoscale DiscussionSPCCape Girardeau, Mississippi, New Madrid, Pemiscot, Perry, Scott and 1 more59 min
May 27, 1:36 PM CDTSevere Thunderstorm WatchSPCCape Girardeau, Dunklin, Mississippi, New Madrid, Pemiscot, Saint Charles and 4 more7 hr
May 27, 3:29 PM CDTMesoscale DiscussionSPCBollinger, Butler, Carter, Crawford, Dent, Howell and 14 more91 min
May 27, 3:50 PM CDTMesoscale DiscussionSPCMississippi, New Madrid, Pemiscot, Scott85 min
May 27, 4:24 PM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Carter, Dent, Iron and 8 more66 min
May 27, 5:13 PM CDTSevere Thunderstorm Watch PDSSPCCape Girardeau, Dunklin, Mississippi, New Madrid, Pemiscot, Scott and 1 more7 hr
May 27, 5:56 PM CDTMesoscale DiscussionSPCBenton, Boone, Callaway, Camden, Cole, Cooper and 18 more64 min
May 27, 6:26 PM CDTSevere Thunderstorm WatchSPCBarton, Benton, Boone, Callaway, Camden, Cedar and 28 more3 hr

Nearby

Mesoscale Discussions in Arkansas, 2017Mesoscale Discussions in Missouri, 2017Every mesoscale discussion in 2017

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.