Alert archive / Texas / Mesoscale Discussions in 2003
Mesoscale Discussion 2513
The Storm Prediction Center issued this mesoscale discussion at Nov 17, 2003, 10:53 PM CST for Beauregard Parish, Calcasieu Parish, Louisiana; 14 counties in Texas. It was in force for 97 min.
The area
The outline as issued.
The facts
- Issued
- Nov 17, 2003, 10:53 PM CST (04:53 UTC)
- Expired
- Nov 18, 2003, 12:30 AM CST
- In force
- 97 min
- Issued by
- the Storm Prediction Center
Counties Beauregard Parish, LA, Calcasieu Parish, LA, Brazoria County, TX, Chambers County, TX, Fort Bend County, TX, Galveston County, TX, Hardin County, TX, Harris County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Matagorda County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Tyler County, TX
The radar
The Houston radar (KHGX), 8 km from the middle of the area, began a volume at 04:59 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
Lake Charles Mun, LA (KLCH), launched 00:00Z, 4.9 hours before the alert went out and 188 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
- 877 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 631 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km storm-relative helicity
- 200 m²/s²
- 0-3 km storm-relative helicity
- 222 m²/s²
- Significant tornado parameter
- 1.2
- Supercell composite
- 7.0
The text
As transmitted, in the capitals the NWS used until 2016.
882 ACUS11 KWNS 180453 SWOMCD SPC MCD 180453 LAZ000-TXZ000-180630- MESOSCALE DISCUSSION 2513 NWS STORM PREDICTION CENTER NORMAN OK 1053 PM CST MON NOV 17 2003 AREAS AFFECTED...SERN TX INTO EXTREME SWRN LA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 180453Z - 180630Z TORNADO WATCH 952 REMNANTS OF OUTFLOW/COASTAL BOUNDARIES HAVE BEEN ADVECTED NWD ON INCREASING SLY LOW LEVEL FLOW...AND CURRENTLY EXTEND FROM NATCHITOCHES-SABINE PARISHES WSW TO A CONFLUENT AXIS VCNTY KGLS. GENESIS FOR CONVECTION CONTINUES IN THE KGLS REGION...WITH STORMS MOVING NWD ALONG THE CONFLUENT AXIS...THEN NEWD ALONG/SOUTH OF THE OUTFLOW. MOISTURE RICH AIR MASS ALONG/SE OF THESE STORMS ALONG WITH FAVORABLE STORM RELATIVE HELICITY WILL CONTINUE THE TORNADO THREAT ACROSS THE SABINE RIVER COUNTIES/PARISHES INTO SWRN LA THE NEXT SEVERAL HOURS. MOREOVER...NE-SW ORIENTED BAND OF TSTMS HAS MADE PROGRESS TOWARD THE HOUSTON METRO AREA AND WILL OVERTAKE THE CONFLUENT AXIS BY 0530-0630 UTC AND WILL NOT ONLY BOOST RAINFALL RATES...BUT COULD GIVE LOCAL WIND DAMAGE/MARGINALLY SEVERE HAIL. TORNADO WATCH 952 WILL LIKELY BE REISSUED FOR NEARLY THE SAME AREA BY ABOUT 0515 UTC. SEVERE THUNDERSTORM WATCH 953 LINE OF TSTMS CONTINUES TO MOVE EWD INTO EXTREME SERN TX AT 25 KTS AND SHOULD BE ALONG THE ERN EDGE OF THE WATCH...MOVING INTO WT 952 BY 06 UTC. HOWEVER...ADDITIONAL TSTMS DEVELOPING UPSTREAM CLOSER TO THE TROUGH AXIS WILL MOVE INTO THE ENTIRE WATCH LATER TONIGHT. IT APPEARS THE MAIN SEVERE THREATS HAVE MOVED FARTHER EAST... THOUGH ISOLD MARGINALLY SEVERE HAIL/DAMAGING WINDS MAY OCCUR. PRIND THAT WS 953 WILL BE ALLOWED TO EXPIRE AT 06 UTC. ..RACY.. 11/18/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LCH...HGX...CRP... 28689648 31019473 31069279 28839392 28639561
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 17, 7:48 PM CST | Mesoscale Discussion | SPC | Bossier, Caddo, Claiborne, Webster | 87 min |
| Nov 17, 8:10 PM CST | Mesoscale Discussion | SPC | Beauregard, Calcasieu, Natchitoches, Sabine, Vernon | 95 min |
| Nov 17, 9:25 PM CST | Tornado Watch | SPC | Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 12 more | 7 hr |
| Nov 17, 11:44 PM CST | Mesoscale Discussion | SPC | Bienville, Bossier, Caldwell, Claiborne, De Soto, Grant and 11 more | 91 min |
| Nov 17, 11:50 PM CST | Tornado Watch | SPC | Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 2 more | 5 hr |
| Nov 18, 2:08 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Avoyelles, Catahoula, Concordia, East Baton Rouge and 25 more | 97 min |
| Nov 18, 2:25 AM CST | Tornado Watch | SPC | Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more | 6 hr |
| Nov 18, 4:48 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Concordia, East Baton Rouge, East Feliciana, Iberville and 17 more | 117 min |
| Nov 18, 6:08 AM CST | Mesoscale Discussion | SPC | Ascension, Jefferson, Lafourche, Livingston, Orleans, Plaquemines and 8 more | 2 hr |
| Nov 18, 6:55 AM CST | Tornado Watch | SPC | Ascension, Assumption, East Baton Rouge, Jefferson, Lafourche, Livingston and 11 more | 5 hr |
| Nov 18, 10:30 AM CST | Mesoscale Discussion | SPC | Saint Bernard | 90 min |
| Nov 17, 6:55 PM CST | Severe Thunderstorm Watch | SPC | Austin, Brazoria, Colorado, Fort Bend, Grimes, Harris and 12 more | 5 hr |
Nearby
Mesoscale Discussions in Texas, 2003Mesoscale Discussions in Louisiana, 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.