Alert archive / Arkansas / Mesoscale Discussions in 2015

Mesoscale Discussion 821

May 28, 201510 counties in Arkansas; LeFlore County, McCurtain County, Sequoyah County, Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 28, 2015, 10:37 AM CDT for 10 counties in Arkansas; LeFlore County, McCurtain County, Sequoyah County, Oklahoma. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
May 28, 2015, 10:37 AM CDT (15:37 UTC)
Expired
May 28, 2015, 11:30 AM CDT
In force
53 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Crawford County, AR, Franklin County, AR, Howard County, AR, Logan County, AR, Montgomery County, AR, Pike County, AR, Polk County, AR, Scott County, AR, Sebastian County, AR, Sevier County, AR, LeFlore County, OK, McCurtain County, OK, Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 51 km from the middle of the area, began a volume at 15:38 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

Springfield, MO (KSGF), launched 12:00Z, 3.6 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, Springfield, MO at 12:00Z on 2015-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1203 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 12:00Z on 2015-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 square meters per square second.1939Sfc1 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
1203 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
811 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

822 
ACUS11 KWNS 281538
SWOMCD
SPC MCD 281537 
ARZ000-OKZ000-281630-

MESOSCALE DISCUSSION 0821
NWS STORM PREDICTION CENTER NORMAN OK
1037 AM CDT THU MAY 28 2015

AREAS AFFECTED...WRN AR...FAR ERN OK

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 281537Z - 281630Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A THREAT FOR STRONG TO LOCALLY SVR WINDS MAY ACCOMPANY A
MCS MOVING INTO WRN AR OVER THE NEXT COUPLE HRS. A WW IS NOT
CURRENTLY ANTICIPATED.

DISCUSSION...RECENT RADAR TRENDS INDICATE LEADING EDGE OF CONVECTION
ASSOCIATED WITH A LONG-LIVED MCS HAS INTENSIFIED ACROSS SERN/E-CNTRL
OK...WITH STRONG TO LOCALLY SVR WIND GUSTS LIKELY ACCOMPANYING PARTS
OF THE LINE. A MOIST/UNSTABLE AIR MASS IS IN PLACE DOWNSHEAR FROM
THE MCS...BUT VWP DATA FROM LIT SUGGESTS DEEP-LAYER SHEAR WEAKENS
WITH EWD EXTENT INTO CNTRL AR. THE THREAT FOR SVR WINDS IS NOT
EXPECTED TO EXTEND TOO FAR EAST INTO AR...ALTHOUGH CONVECTION MAY
PERSIST INTO THE EARLY AFTERNOON.

..ROGERS/GOSS.. 05/28/2015

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

ATTN...WFO...LZK...SHV...TSA...

LAT...LON   35609365 34549347 33769384 33679447 33899502 34449502
            35249505 35729484 35899392 35609365

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 2:50 AM CDTMesoscale DiscussionSPCCaddo, Carter, Comanche, Cotton, Garvin, Grady and 11 more2 hr
May 28, 2:18 PM CDTSevere Thunderstorm WatchSPCBeaver, Cimarron, Texas7 hr
May 28, 2:56 PM CDTMesoscale DiscussionSPCBryan, Carter, Coal, Comanche, Cotton, Garvin and 9 more94 min
May 28, 3:26 PM CDTSevere Thunderstorm WatchSPCCaddo, Canadian, Carter, Cleveland, Comanche, Cotton and 13 more8 hr
May 28, 5:33 PM CDTMesoscale DiscussionSPCBeaver, Cimarron, Harper, Texas87 min

Nearby

Mesoscale Discussions in Arkansas, 2015Mesoscale Discussions in Oklahoma, 2015Every mesoscale discussion in 2015

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.