Alert archive / Oklahoma / Mesoscale Discussions in 2013

Mesoscale Discussion 607

May 9, 201318 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 9, 2013, 12:53 AM CDT for 18 counties in Oklahoma. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 9, 2013, 12:53 AM CDT (05:53 UTC)
Expired
May 9, 2013, 3:00 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Blaine County, OK, Caddo County, OK, Canadian County, OK, Cleveland County, OK, Creek County, OK, Custer County, OK, Garfield County, OK, Grady County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, Noble County, OK, Oklahoma County, OK, Pawnee County, OK, Payne County, OK, Pottawatomie County, OK, Washita County, OK

The radar

The Norman radar (KTLX), 65 km from the middle of the area, began a volume at 05:54 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

Norman, OK (KOUN), launched 00:00Z, 5.9 hours before the alert went out and 67 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, Norman, OK at 00:00Z on 2013-05-09Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Norman, OK at 00:00Z on 2013-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.193958Sfc1 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
3283 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
113 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.

477 
ACUS11 KWNS 090554
SWOMCD
SPC MCD 090553 
OKZ000-090800-

MESOSCALE DISCUSSION 0607
NWS STORM PREDICTION CENTER NORMAN OK
1253 AM CDT THU MAY 09 2013

AREAS AFFECTED...N CNTRL OK

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 090553Z - 090800Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...THUNDERSTORMS ARE EXPECTED TO MOVE FROM NWRN INTO N CNTRL
OK TONIGHT...WITH MARGINAL HAIL OR WIND EXPECTED. THE THREAT DOES
NOT CURRENTLY NECESSITATE A WATCH.

DISCUSSION...STORMS HAVE RECENTLY INCREASED ALONG THE COLD FRONT
OVER NWRN OK. MEANWHILE...MUCH OF THE SURFACE AIR MASS HAS BEEN
STABILIZED ACROSS CNTRL OK IN THE WAKE OF EARLIER CONVECTION...NOW A
DYING MCS ACROSS NERN OK. 

A STRONG SLY LOW LEVEL JET PERSISTS...WHICH IS HELPING TO MAINTAIN
AN ELEVATED FEED OF MOISTURE AND INSTABILITY ATOP OF OUTFLOW
BOUNDARY WHICH EXTENDED FROM W CNTRL INTO S CNTRL OK. THE COOL AIR
ALOFT WOULD TEND TO FAVOR A FEW HAIL CORES...BUT MARGINAL DEEP LAYER
SHEAR AND DECREASING ELEVATED INSTABILITY WITH TIME SHOULD MITIGATE
ANY SEVERE WIND THREAT.

..JEWELL/KERR.. 05/09/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   35599926 35799921 36499823 36579740 36409660 36039629
            35579626 35189657 34969747 35079833 35289903 35599926

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 8, 8:56 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Carter, Cleveland and 27 more94 min
May 9, 5:38 PM CDTMesoscale DiscussionSPCBeckham, Caddo, Comanche, Greer, Harmon, Jackson and 2 more67 min

Nearby

Mesoscale Discussions in Oklahoma, 2013Every mesoscale discussion in 2013

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.