Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 472

April 7, 201218 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Apr 7, 2012, 10:17 AM CDT for 18 counties in Oklahoma. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
Apr 7, 2012, 10:17 AM CDT (15:17 UTC)
Expired
Apr 7, 2012, 11:45 AM CDT
In force
88 min
Issued by
the Storm Prediction Center

Counties Blaine County, OK, Caddo County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, Noble County, OK, Oklahoma County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Stephens County, OK

The radar

The Norman radar (KTLX), 55 km from the middle of the area, began a volume at 15:18 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 12:00Z, 3.3 hours before the alert went out and 56 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 12:00Z on 2012-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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, Norman, OK at 12:00Z on 2012-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 375 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
905 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
375 m²/s²
0-3 km storm-relative helicity
466 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

779 
ACUS11 KWNS 071517
SWOMCD
SPC MCD 071517 
OKZ000-071645-

MESOSCALE DISCUSSION 0472
NWS STORM PREDICTION CENTER NORMAN OK
1017 AM CDT SAT APR 07 2012

AREAS AFFECTED...CENTRAL OKLAHOMA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 071517Z - 071645Z

THE NEED FOR A WW IS NOT ANTICIPATED...AT LEAST IN THE NEAR TERM. 
HOWEVER...TRENDS WILL BE MONITORED FOR THE POSSIBILITY OF INCREASING
SEVERE POTENTIAL THAT COULD REQUIRE ONE LATER THIS AFTERNOON.

AS A SIGNIFICANT UPPER TROUGH PROGRESSES EASTWARD ACROSS THE
NORTHERN PLAINS...AN ASSOCIATED SURFACE FRONT APPEARS LIKELY TO
CONTINUE TO ADVANCE ACROSS THE CENTRAL AND SOUTHERN PLAINS.  THIS
PROBABLY WILL OCCUR MORE RAPIDLY SOUTHWARD THROUGH THE HIGH
PLAINS...THAN EASTWARD THROUGH THE LOWER PLAINS.  MODELS ARE
SUGGESTIVE THAT A COMBINATION OF FRONTAL LIFT...AND AN AREA OF
ENHANCED LOWER/MID TROPOSPHERIC WARM ADVECTION AHEAD OF IT...WILL
CONTRIBUTE TO RENEWED CONVECTIVE DEVELOPMENT TO THE SOUTH OF A
CLUSTER OF STORMS NOW TO THE NORTH AND WEST OF THE TULSA AREA.  

BASED ON RUC GUIDANCE...INHIBITION APPEARS WEAKEST NEAR THE I-35
CORRIDOR OF CENTRAL OKLAHOMA.  THIS IS WHERE PROBABILITIES FOR
DEVELOPMENT AND SOUTHWARD PROPAGATION OF ACTIVITY APPEARS HIGHEST
BETWEEN NOW AND 18-20Z.  CONVECTION IS EXPECTED TO REMAIN GENERALLY
ELEVATED IN NATURE...EITHER ABOVE THE SOUTHWARD ADVANCING FRONT...OR
ABOVE STABLE PRE-FRONTAL BOUNDARY LAYER AIR.  BUT...STEEP MID-LEVEL
LAPSE RATES ARE CONTRIBUTING TO MODERATELY LARGE CAPE OF 1000-2000
J/KG...IN THE PRESENCE OF MODEST SHEAR...WHICH IS MAINLY THE RESULT
OF SUBSTANTIAL VEERING OF WIND FIELDS WITH HEIGHT.  

OCCASIONAL STRONGER UPDRAFT PULSES CAPABLE OF PRODUCING MARGINALLY
SEVERE HAIL SEEMS TO BE THE PRIMARY THREAT IN THE NEAR TERM.

..KERR.. 04/07/2012

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

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

LAT...LON   36069847 36589786 36849657 36549612 35909672 34569721
            34209809 34449866 35169864 35559867 36069847

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 7, 2:29 PM CDTMesoscale DiscussionSPCCotton, Jefferson, Stephens61 min

Nearby

Mesoscale Discussions in Oklahoma, 2012Every mesoscale discussion in 2012

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.