Alert archive / Oklahoma / Mesoscale Discussions in 2004

Mesoscale Discussion 974

May 29, 200415 counties in Oklahoma; 5 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 29, 2004, 2:33 PM CDT for 15 counties in Oklahoma; 5 counties in Texas. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued: May 29, 2004, 2:33 PM CDT (19:33 UTC)
Expired: May 29, 2004, 4:30 PM CDT
In force: 117 min
Issued by: the Storm Prediction Center

Counties Beckham County, OK, Blaine County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kiowa County, OK, Major County, OK, Roger Mills County, OK, Tillman County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Childress County, TX, Collingsworth County, TX, Hall County, TX, Hardeman County, TX, Wheeler County, TX

The radar

The Altus AFB radar (KFDR), 130 km from the middle of the area, began a volume at 19:34 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.

Tornado Watch 322May 29, 2:55 PM CDT

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 12:00Z, 7.6 hours before the alert went out and 165 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 315 J/kg
Mixed-layer CIN: -252 J/kg
Mixed-layer LCL: 1979 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 322 m²/s²
0-3 km storm-relative helicity: 336 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.

343 
ACUS11 KWNS 291933
SWOMCD
SPC MCD 291933 
OKZ000-TXZ000-292130-

MESOSCALE DISCUSSION 0974
NWS STORM PREDICTION CENTER NORMAN OK
0233 PM CDT SAT MAY 29 2004

AREAS AFFECTED...EXTREME ERN TX PANHANDLE...WRN OK

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 291933Z - 292130Z

MASS FIELDS ARE BECOMING INCREASINGLY FAVORABLE FOR STORM INITIATION
ALONG THE DRYLINE.  A TORNADO WATCH WILL BE ISSUED SHORTLY.

LATEST VISIBLE IMAGERY SHOWS TCU BUILDING ALONG DRYLINE IN THE ERN
TX PANHANDLE INTO WRN OK.  CONVERGENCE HAS NOT BEEN VERY FOCUSED
OVER THE PAST FEW HOURS DUE TO LEAD SHORTWAVE...BUT AREA PROFILERS
IN NM AND W TX INDICATE EFFECTS OF SUBTLE VORTICITY MAXIMA ARE BEING
FELT WITH WINDS AT MID LEVELS BEGINNING TO BACK A BIT.

ALTHOUGH THERE IS NO UNIFORM VEERING OF WINDS BEHIND TCU LINE AT THE
MOMENT...INDICATING SLIGHT DISORGANIZATION OF DRYLINE FORCING
MECHANISM...GIVEN EXTREME INSTABILITY IN PLACE...SEVERE STORM
DEVELOPMENT WILL LIKELY BE VERY QUICK ONCE DEEP CONVERGENCE BECOMES
SUFFICIENT. SUPERCELLS WITH VERY LARGE HAIL DAMAGING WINDS AND
TORNADOES WILL BE LIKELY.

COMBINATION OF TEMPERATURE / DEWPOINT SPREADS 25-30 F AND STRONG SLY
SURFACE FLOW ALONG THE TX/ WRN OK BORDER MAY HOLD MOST SIGNIFICANT
TORNADO THREAT AT BAY INITIALLY...UNTIL STORMS GET INTO DEEPER MOIST
BOUNDARY LAYER INTO WRN OK LATE AFTERNOON / EARLY EVENING.

..JEWELL.. 05/29/2004

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

ATTN...WFO...OUN...LUB...AMA...

34300079 34930041 35700020 36520006 36789885 36569811
34159885 34070093

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 29, 2:55 PM CDT	Tornado Watch	SPC	Alfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 31 more	7 hr
May 29, 4:57 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Blaine, Custer, Dewey, Garfield, Grant and 7 more	63 min

Nearby

Mesoscale Discussions in Oklahoma, 2004 Mesoscale Discussions in Texas, 2004 Every mesoscale discussion in 2004

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.