Alert archive / Texas / Mesoscale Discussions in 2008
Mesoscale Discussion 521
The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2008, 12:20 PM CDT for 10 counties in Oklahoma; 42 counties in Texas. It was in force for 55 min.
The area
The outline as issued.
The facts
- Issued
- Mar 31, 2008, 12:20 PM CDT (17:20 UTC)
- Expired
- Mar 31, 2008, 1:15 PM CDT
- In force
- 55 min
- Issued by
- the Storm Prediction Center
All 52 counties
Atoka County, OK, Bryan County, OK, Carter County, OK, Choctaw County, OK, Cotton County, OK, Jefferson County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, Pushmataha County, OK, Archer County, TX, Bosque County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Concho County, TX, Cooke County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Fannin County, TX, Grayson County, TX, Hamilton County, TX, Hill County, TX, Hood County, TX, Hunt County, TX, Jack County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Lampasas County, TX, McCulloch County, TX, Mills County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Rockwall County, TX, San Saba County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Wichita County, TX, Wise County, TX, Young County, TX
The radar
The Dallas/Ft Worth radar (KFWS), 79 km from the middle of the area, began a volume at 17:22 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
Fort Worth, TX (KFWD), launched 12:00Z, 5.3 hours before the alert went out and 53 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
- 1777 J/kg
- Mixed-layer CIN
- -36 J/kg
- Mixed-layer LCL
- 564 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 169 m²/s²
- 0-3 km storm-relative helicity
- 241 m²/s²
- Significant tornado parameter
- 1.3
- Supercell composite
- 7.2
The text
As transmitted, in the capitals the NWS used until 2016.
000 ACUS11 KWNS 311720 SWOMCD SPC MCD 311720 OKZ000-TXZ000-311815- MESOSCALE DISCUSSION 0521 NWS STORM PREDICTION CENTER NORMAN OK 1220 PM CDT MON MAR 31 2008 AREAS AFFECTED...FAR SRN/SERN OK INTO NRN/CENTRAL TX CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 311720Z - 311815Z WW WILL LIKELY BE REQUIRED DURING THE EARLY AFTERNOON ACROSS FAR SRN/SERN OK INTO NRN AND PARTS OF CENTRAL TX. LATE MORNING SURFACE ANALYSIS SHOWED DRY LINE MIXING EWD WITH INCREASING CONVERGENCE NOTED THROUGH A DEEP LAYER PER OBJECTIVE ANALYSES FROM SWRN OK SWD THROUGH WRN N TX /W OF SPS/ TO ABI TO TX BIG BEND REGION. SUBSIDENCE IN THE WAKE OF A GRAVITY WAVE...WHICH WAS CURRENTLY MOVING ESEWD THROUGH ERN AND SOUTH CENTRAL TX...HAD RESULTED IN MAINLY CLEAR SKIES WWD ACROSS MUCH OF CENTRAL/WRN TX. THIS HAS RESULTED IN STRONG SURFACE HEATING WITHIN A MOIST AIR MASS. THUS...FURTHER DESTABILIZATION IS EXPECTED AS MLCAPE VALUES INCREASE TO GREATER THAN 1500 J/KG. WATER VAPOR IMAGERY INDICATED A MID/UPPER LEVEL SHORT WAVE TROUGH CURRENTLY MOVING INTO FAR ERN NM/W TX...WITH MID TO UPPER LEVEL WSWLY FLOW ACROSS THE SRN PLAINS STRENGTHENING WITH APPROACH OF THIS TROUGH. ASCENT WITH THIS FEATURE IS EXPECTED TO AID IN TSTM DEVELOPMENT...WITH VISIBLE IMAGERY ALREADY SHOWING CU FORMATION IN THE VICINITY OF BWD AND NWD ALONG DRY LINE. MODERATE INSTABILITY AND INCREASING DEEP LAYER SHEAR VALUES WILL SUPPORT DISCRETE SUPERCELLS. ..PETERS.. 03/31/2008 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...FWD...OUN...EWX...SJT... 34699506 33149559 32369657 31419759 30869893 31260015 32879932 34219872 34219872 34849867 34319817 34319705
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 30, 8:50 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Blaine, Canadian, Custer, Garfield, Grant and 4 more | 55 min |
| Mar 30, 10:52 PM CDT | Tornado Watch | SPC | Alfalfa, Blaine, Caddo, Canadian, Cleveland, Creek and 16 more | 6 hr |
| Mar 31, 1:17 AM CDT | Mesoscale Discussion | SPC | Alfalfa, Blaine, Caddo, Canadian, Cleveland, Creek and 16 more | 88 min |
| Mar 31, 2:52 AM CDT | Mesoscale Discussion | SPC | Garfield, Grant, Kay, Logan, Noble, Osage and 2 more | 53 min |
| Mar 31, 4:00 AM CDT | Mesoscale Discussion | SPC | Pawnee | 90 min |
| Mar 31, 4:29 AM CDT | Mesoscale Discussion | SPC | Craig, Creek, Kay, Mayes, Nowata, Osage and 5 more | 91 min |
| Mar 31, 5:05 AM CDT | Severe Thunderstorm Watch | SPC | Craig, Mayes, Nowata, Osage, Pawnee, Rogers and 2 more | 7 hr |
| Mar 31, 6:17 AM CDT | Mesoscale Discussion | SPC | Craig, Delaware, Kay, Mayes, Nowata, Osage and 6 more | 88 min |
| Mar 31, 7:50 AM CDT | Mesoscale Discussion | SPC | Blaine, Craig, Garfield, Kay, Kingfisher, Logan and 9 more | 85 min |
| Mar 31, 8:44 AM CDT | Tornado Watch | SPC | Adair, Caddo, Canadian, Cherokee, Cleveland, Coal and 37 more | 7 hr |
| Mar 31, 10:30 AM CDT | Mesoscale Discussion | SPC | Adair, Caddo, Canadian, Cherokee, Cleveland, Coal and 37 more | 60 min |
| Mar 31, 2:00 PM CDT | Tornado Watch | SPC | Atoka, Bryan, Carter, Choctaw, Jefferson, Johnston and 3 more | 7 hr |
| Mar 31, 3:04 PM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Coal, Haskell, Hughes, Latimer and 6 more | 26 min |
| Mar 31, 3:45 PM CDT | Tornado Watch | SPC | Adair, Cherokee, Choctaw, Coal, Haskell, Hughes and 8 more | 7 hr |
| Mar 31, 3:49 PM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Carter, Choctaw, Jefferson, Johnston and 3 more | 56 min |
| Mar 31, 6:12 PM CDT | Tornado Watch | SPC | McCurtain | 7 hr |
| Mar 31, 5:28 PM CDT | Mesoscale Discussion | SPC | Bowie, Red River | 62 min |
Nearby
Mesoscale Discussions in Texas, 2008Mesoscale Discussions in Oklahoma, 2008Every mesoscale discussion in 2008
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.