Alert archive / Oklahoma / Mesoscale Discussions in 2003
Mesoscale Discussion 474
The Storm Prediction Center issued this mesoscale discussion at Apr 15, 2003, 11:00 PM CDT for 27 counties in Oklahoma; 6 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 15, 2003, 11:00 PM CDT (04:00 UTC)
- Expired
- Apr 16, 2003, 1:00 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 33 counties
Canadian County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Cotton County, OK, Creek County, OK, Garvin County, OK, Grady County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Noble County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Pawnee County, OK, Payne County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Archer County, TX, Clay County, TX, Cooke County, TX, Jack County, TX, Montague County, TX, Wise County, TX
The radar
The Norman radar (KTLX), 82 km from the middle of the area, began a volume at 04:02 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.
The nearest sounding before it
Norman, OK (KOUN), launched 00:00Z, 4.0 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.
- Mixed-layer CAPE
- 15 J/kg
- Mixed-layer CIN
- -337 J/kg
- Mixed-layer LCL
- 1137 m above ground
- 0-6 km bulk shear
- 65 kt
- 0-1 km storm-relative helicity
- 380 m²/s²
- 0-3 km storm-relative helicity
- 627 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
910 ACUS11 KWNS 160401 SWOMCD SPC MCD 160400 OKZ000-TXZ000-160600- MESOSCALE DISCUSSION 0474 NWS STORM PREDICTION CENTER NORMAN OK 1100 PM CDT TUE APR 15 2003 AREAS AFFECTED...CENTRAL/SRN OK...NORTH CENTRAL TX CONCERNING...TORNADO WATCH 124... VALID 160400Z - 160600Z ...SECONDARY LINE OF THUNDERSTORMS IS INCREASING AS IT ENTERS WRN PORTIONS OF TORNADO WATCH... INTENSIFYING LINE OF THUNDERSTORMS HAS DEVELOPED FROM KAY COUNTY...SWWD TO COMMANCHE COUNTY IN RESPONSE TO APPROACHING SPEED MAX AND ASSOCIATED LARGE SCALE UPPER DIVERGENCE. LOCAL PROFILER/VWP DATA CONTINUES TO INDICATE VERY STRONG LOW LEVEL SHEAR WITH 0-3KM HELICITY VALUES RANGING FROM 600-900 M2/S2. DURING THE LAST HALF HOUR...A SUPERCELL HAS DEVELOPED OVER GRADY COUNTY AND APPEARS TO BE INCREASING AS IT LIFTS NEWD TOWARD NRN MCCLAIN COUNTY. ISOLATED TORNADOES REMAIN POSSIBLE...ESPECIALLY WITH THIS STORM. ..DARROW.. 04/16/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...FWD...OUN... 33349894 35569807 36709740 35999572 34469618 33069773
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 15, 7:11 PM CDT | Mesoscale Discussion | SPC | Comanche, Harmon, Jackson, Tillman | 2 hr |
| Apr 15, 8:35 PM CDT | Mesoscale Discussion | SPC | Carter, Cleveland, Creek, Garvin, Grady, Jefferson and 16 more | 115 min |
| Apr 15, 9:00 PM CDT | Tornado Watch | SPC | Carter, Cleveland, Coal, Creek, Garvin, Grady and 15 more | 5 hr |
| Apr 15, 9:04 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Blaine, Caddo, Canadian, Comanche, Cotton and 10 more | 86 min |
| Apr 15, 11:20 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Cherokee, Craig, Creek, Delaware, Haskell and 17 more | 6 hr |
| Apr 16, 2:01 AM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Craig, Delaware, Haskell, Latimer and 12 more | 119 min |
| Apr 16, 1:41 AM CDT | Mesoscale Discussion | SPC | Brown, Comanche, Coryell, Erath, Hamilton, Kimble and 8 more | 2 hr |
Nearby
Mesoscale Discussions in Oklahoma, 2003Mesoscale Discussions in Texas, 2003Every mesoscale discussion in 2003
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.