Alert archive / Texas / Mesoscale Discussions in 2004
Mesoscale Discussion 2413
The Storm Prediction Center issued this mesoscale discussion at Nov 20, 2004, 1:55 PM CST for 34 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 20, 2004, 1:55 PM CST (19:55 UTC)
- Expired
- Nov 20, 2004, 4:00 PM CST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 34 counties
Bosque County, TX, Brown County, TX, Burnet County, TX, Callahan County, TX, Coleman County, TX, Comanche County, TX, Concho County, TX, Coryell County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Hamilton County, TX, Hill County, TX, Hood County, TX, Irion County, TX, Johnson County, TX, Kimble County, TX, Lampasas County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, McLennan County, TX, Menard County, TX, Mills County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, San Saba County, TX, Schleicher County, TX, Somervell County, TX, Sutton County, TX, Tarrant County, TX, Taylor County, TX, Tom Green County, TX
The nearest sounding before it
Fort Worth, TX (KFWD), launched 12:00Z, 7.9 hours before the alert went out and 228 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
- 36 J/kg
- Mixed-layer CIN
- -119 J/kg
- Mixed-layer LCL
- 895 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 35 m²/s²
- 0-3 km storm-relative helicity
- 91 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
609 ACUS11 KWNS 201955 SWOMCD SPC MCD 201955 TXZ000-202200- MESOSCALE DISCUSSION 2413 NWS STORM PREDICTION CENTER NORMAN OK 0155 PM CST SAT NOV 20 2004 AREAS AFFECTED...CENTRAL TX CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 201955Z - 202200Z ISOLATED SEVERE HAIL STORMS ARE EXPECTED OVER THE NEXT SEVERAL HOURS. ELEVATED STORMS HAVE FORMED N OF SURFACE BOUNDARY WHERE WEAK SLY FLOW ABOVE MORE STABLE SURFACE AIR IS MAINTAINING FEED OF MARGINAL INSTABILITY. ENVIRONMENT WILL REMAIN FAVORABLE FOR CONTINUED DEVELOPMENT AS SRN EDGE OF LEAD VORT MAX OVERSPREADS THE AREA. SURFACE ANALYSIS SHOWS TEMPERATURES HAVE WARMED INTO THE LOWER 70S OVER MUCH OF NERN TX WITH DEWPOINTS NEAR 60. MODIFIED SOUNDINGS YIELD SUFFICIENT INSTABILITY FOR HAIL PRODUCTION. JUXTAPOSITION OF FAVORABLE SELY LOW LEVEL FLOW AND 50 KT SWLY MID LEVEL FLOW IS FAVORABLE FOR LONG-LIVED CONVECTION PRODUCING LARGE HAIL. ..JEWELL.. 11/20/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FWD...EWX...SJT... 30569840 30279974 30350067 30980122 31640092 32469968 32959819 32689680 31789649
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 19, 11:26 PM CST | Mesoscale Discussion | SPC | Brazoria, Calhoun, Chambers, Fort Bend, Galveston, Harris and 4 more | 2 hr |
| Nov 20, 12:23 PM CST | Mesoscale Discussion | SPC | Bee, Calhoun, Goliad, Jackson, Live Oak, Matagorda and 3 more | 3 hr |
| Nov 20, 5:11 PM CST | Mesoscale Discussion | SPC | Brazoria, Calhoun, Colorado, Fort Bend, Jackson, Lavaca and 3 more | 2 hr |
Nearby
Mesoscale Discussions in Texas, 2004Every 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.