Alert archive / Kansas / Mesoscale Discussions in 2017

Mesoscale Discussion 784

May 19, 201710 counties in Kansas; Grant County, Kay County, Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 19, 2017, 3:28 PM CDT for 10 counties in Kansas; Grant County, Kay County, Oklahoma. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
May 19, 2017, 3:28 PM CDT (20:28 UTC)
Expired
May 19, 2017, 5:00 PM CDT
In force
92 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Butler County, KS, Chase County, KS, Chautauqua County, KS, Cowley County, KS, Elk County, KS, Greenwood County, KS, Harper County, KS, Harvey County, KS, Sedgwick County, KS, Sumner County, KS, Grant County, OK, Kay County, OK

The radar

The Wichita radar (KICT), 31 km from the middle of the area, began a volume at 20:31 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 (KFOE), launched 12:00Z, 8.5 hours before the alert went out and 221 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 2017-05-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 36 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 2017-05-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 229 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
36 J/kg
Mixed-layer CIN
-135 J/kg
Mixed-layer LCL
538 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
229 m²/s²
0-3 km storm-relative helicity
256 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

199 
ACUS11 KWNS 192029
SWOMCD
SPC MCD 192028 
KSZ000-OKZ000-192200-

Mesoscale Discussion 0784
NWS Storm Prediction Center Norman OK
0328 PM CDT Fri May 19 2017

Areas affected...South-central KS...Northern OK

Concerning...Severe potential...Watch possible 

Valid 192028Z - 192200Z

Probability of Watch Issuance...40 percent

SUMMARY...Severe threat is increasing across south-central KS and
extreme northern OK.  Hail is the primary threat, though an isolated
tornado can not be ruled out.

DISCUSSION...A narrow corridor of modest boundary-layer heating has
developed from western OK into extreme south-central KS, per
surface-3km lapse rates on the order of 7 C/km.  With minimal CINH
observed across this portion of KS/OK convection is expected to
gradually increase with continued heating, albeit modest due to
extensive cloud cover.  Over the last hour or so thunderstorms have
gradually increased across southwest KS along the cold front.  This
activity is expected to shift east into an air mass characterized by
dew points in the mid 60s with mid 70s temperatures.  While
low-level shear is currently weak, deep-layer shear is more than
adequate for sustained rotating updrafts and a few supercells could
evolve across this region.  Backed low-level flow may contribute to
the tornado potential, though hail is the primary risk.

..Darrow/Kerr.. 05/19/2017

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

ATTN...WFO...TSA...TOP...ICT...OUN...

LAT...LON   36969828 37939804 38479671 38009586 37189582 36609751
            36969828

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 18, 7:06 PM CDTMesoscale DiscussionSPCAtchison, Brown, Chase, Clay, Coffey, Dickinson and 23 more84 min
May 18, 9:41 PM CDTMesoscale DiscussionSPCBourbon, Cherokee, Crawford, Johnson, Linn, Miami94 min
May 18, 9:41 PM CDTSevere Thunderstorm WatchSPCAtchison, Doniphan, Johnson, Leavenworth, Linn, Miami and 1 more4 hr
May 19, 4:47 PM CDTTornado WatchSPCButler, Chase, Chautauqua, Cowley, Elk, Greenwood and 9 more4 hr
May 19, 6:45 PM CDTMesoscale DiscussionSPCButler, Chase, Chautauqua, Cowley, Elk, Greenwood and 10 more60 min
May 18, 7:19 PM CDTMesoscale DiscussionSPCAlfalfa, Garfield, Grant, Major, Woods26 min
May 18, 7:43 PM CDTMesoscale DiscussionSPCCarter, Jefferson, Johnston, Love, Murray, Pontotoc62 min
May 18, 7:47 PM CDTSevere Thunderstorm WatchSPCAlfalfa, Atoka, Bryan, Canadian, Carter, Cleveland and 26 more6 hr
May 19, 10:41 AM CDTMesoscale DiscussionSPCCarter, Jefferson, Love, Marshall94 min
May 19, 2:13 PM CDTMesoscale DiscussionSPCAdair, Ottawa, Sequoyah92 min
May 19, 3:26 PM CDTTornado WatchSPCAdair, Atoka, Bryan, Carter, Cherokee, Choctaw and 19 more11 hr
May 19, 6:56 PM CDTMesoscale DiscussionSPCAdair, Atoka, Bryan, Carter, Cherokee, Choctaw and 24 more2 hr

Nearby

Mesoscale Discussions in Kansas, 2017Mesoscale Discussions in Oklahoma, 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.