Alert archive / Oklahoma / Mesoscale Discussions in 2007

Mesoscale Discussion 1949

September 8, 200720 counties in Oklahoma; Gray County, Hemphill County, Wheeler County, Texas

The Storm Prediction Center issued this mesoscale discussion at Sep 8, 2007, 1:14 AM CDT for 20 counties in Oklahoma; Gray County, Hemphill County, Wheeler County, Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Sep 8, 2007, 1:14 AM CDT (06:14 UTC)
Expired
Sep 8, 2007, 4:15 AM CDT
In force
3 hr
Issued by
the Storm Prediction Center
All 23 counties

Blaine County, OK, Cherokee County, OK, Creek County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, Major County, OK, Muskogee County, OK, Noble County, OK, Okmulgee County, OK, Pawnee County, OK, Payne County, OK, Roger Mills County, OK, Tulsa County, OK, Wagoner County, OK, Woodward County, OK, Gray County, TX, Hemphill County, TX, Wheeler County, TX

The radar

The Norman radar (KTLX), 96 km from the middle of the area, began a volume at 06:15 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, 6.2 hours before the alert went out and 95 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 2007-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1808 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 00:00Z on 2007-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 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
1808 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
819 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
268 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.

000 
ACUS11 KWNS 080615
SWOMCD
SPC MCD 080614 
OKZ000-TXZ000-080915-

MESOSCALE DISCUSSION 1949
NWS STORM PREDICTION CENTER NORMAN OK
0114 AM CDT SAT SEP 08 2007

AREAS AFFECTED...PORTIONS NRN/WRN OK...E-CENTRAL/NERN PANHANDLE OF
TX.

CONCERNING...HEAVY RAINFALL 

VALID 080614Z - 080915Z

BAND OF TSTMS HAS BEEN INCREASING IN COVERAGE FOR A COUPLE
HOURS...FROM CHEROKEE-GARFIELD-ROGER MILLS COUNTIES OK INTO GRAY
COUNTY TX.  THIS ACTIVITY SHOULD PERSIST WITH MINOR FLUCTUATIONS IN
ITS MESOSCALE GEOMETRY...PERHAPS INCLUDING SLGT NET SWD
DRIFT...THROUGH 9Z. RAIN RATES 1-2 INCHES/HOUR WILL BE
COMMON...LOCALLY AROUND 2.5 INCHES/HOUR IN HEAVIEST CORES.  WITH
LITTLE MOVEMENT EXPECTED FOR ASSOCIATED MAIN ZONE OF LOW LEVEL
LIFT...PERSISTENT HEAVY RAIN EVENT WITH TRAINING/MERGING OF CELLS
WILL ENHANCE HEAVY RAIN HAZARD.

SFC MESOANALYSIS SHOWS QUASISTATIONARY FRONTAL/OUTFLOW BOUNDARY FROM
NEAR FSM NWWD ACROSS OKMULGEE COUNTY OK THEN WSWWD ACROSS SRN GRADY
COUNTY TO WEAK CYCLONE NEAR HARMON/JACKSON COUNTY LINE...IN  OK. 
ALTHOUGH COLD POOL GENERATION WITH EXISTING CONVECTION WILL NOT BE
VERY ROBUST...IN PART BECAUSE OF VERY MOIST/NEARLY SATURATED
CHARACTER OF BOUNDARY LAYER...WEAK KINEMATIC FORCING ASSOCIATED WITH
OUTFLOW FROM ONGOING STORMS SHOULD REINFORCE THIS BOUNDARY.  PRIMARY
LOW LEVEL FRONTAL ZONE LIES FARTHER N...NEARLY COINCIDENT WITH
EXISTING ACTIVITY.  ALTHOUGH LOW LEVEL WINDS WILL NOT GET
PARTICULARLY STRONG...EXPECT DEEP LAYER OF WEAK-MDT CONVERGENCE TO
CONTINUE OVER THIS ZONE...EVEN AS 850 MB FLOW VEERS TOWARD WSWLY
THROUGH REMAINDER PRE-DAWN HOURS.  MCV IS INDICATED IN REFLECTIVITY
ANIMATIONS AND IN PROFILER/VWP STREAMLINE ANALYSES OVER NWRN OK
VICINITY ROGER MILLS/ELLIS COUNTY LINE.  THIS FEATURE SHOULD DRIFT
EWD PARALLEL TO AND N OF SFC BOUNDARY...ENHANCING LOW LEVEL ASCENT
OF VERY MOIST AIR ABOVE SFC.  RUC FCST SOUNDINGS AND GPS DATA
INDICATE PW COMMONLY AROUND 2 INCHES ACROSS THIS CORRIDOR...AND AS
MUCH AS 2.3 INCHES INVOF TUL...WITH 500-1500 J/KG MUCAPE IN SUPPORT
OF TSTM POTENTIAL.

..EDWARDS.. 09/08/2007

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

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

35670095 36609906 36569783 36379590 36039475 35749492
35519556 35799758 35459897 35210030 35300097

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 7, 7:03 PM CDTMesoscale DiscussionSPCBriscoe, Childress, Cottle, Crosby, Dickens, Floyd and 6 more87 min

Nearby

Mesoscale Discussions in Oklahoma, 2007Mesoscale Discussions in Texas, 2007Every mesoscale discussion in 2007

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.