Alert archive / Missouri / Mesoscale Discussions in 2021
Mesoscale Discussion 449
The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2021, 10:56 AM CDT for Fulton County, Arkansas; 7 counties in Missouri. It was in force for 64 min.
The area
The outline as issued.
The facts
- Issued
- Apr 28, 2021, 10:56 AM CDT (15:56 UTC)
- Expired
- Apr 28, 2021, 12:00 PM CDT
- In force
- 64 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 117
Counties Fulton County, AR, Douglas County, MO, Howell County, MO, Oregon County, MO, Ozark County, MO, Shannon County, MO, Texas County, MO, Wright County, MO
The radar
The Springfield radar (KSGF), 131 km from the middle of the area, began a volume at 15:59 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 nearest sounding before it
Springfield, MO (KSGF), launched 12:00Z, 3.9 hours before the alert went out and 160 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
- 34 J/kg
- Mixed-layer CIN
- -105 J/kg
- Mixed-layer LCL
- 1441 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 84 m²/s²
- 0-3 km storm-relative helicity
- 127 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
102
ACUS11 KWNS 281557
SWOMCD
SPC MCD 281556
MOZ000-ARZ000-281700-
Mesoscale Discussion 0449
NWS Storm Prediction Center Norman OK
1056 AM CDT Wed Apr 28 2021
Areas affected...Portions of southern MO and extreme northern AR
Concerning...Tornado Watch 117...
Valid 281556Z - 281700Z
The severe weather threat for Tornado Watch 117 continues.
SUMMARY...An isolated damaging wind and tornado threat may continue
in the short term across Tornado Watch 117.
DISCUSSION...A bowing complex with a history of producing multiple
damaging wind reports across southern MO earlier this morning
appears to be struggling to maintain its intensity based on recent
radar imagery. A downstream surface observation at KUNO in
south-central MO shows an air temperature only in the upper 60s.
Although sufficient low-level moisture is in place ahead of the
ongoing convection, weak instability with MLCAPE around 250-500 J/kg
may continue to hamper updraft intensity and longevity this morning.
Still, the low-level flow from the KLZK VWP remains favorable for
some rotation with any segment of the bowing complex that can remain
surface based. Accordingly, an isolated severe/damaging wind and
tornado threat may continue in the short term across remaining valid
portions of Tornado Watch 117. It remains unclear whether this
convection in southern MO and far northern AR will remain
sufficiently organized into the afternoon to warrant additional
downstream watch issuance.
..Gleason.. 04/28/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...LSX...LZK...SGF...
LAT...LON 36589102 36409112 36309266 36569263 36809272 37089283
37309280 37419253 37429157 37319106 36589102SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 3:01 AM CDT | Tornado Watch | SPC | Benton, Carroll, Crawford, Madison, Washington | 7 hr |
| Apr 28, 6:35 AM CDT | Mesoscale Discussion | SPC | Washington | 3 hr |
| Apr 28, 8:52 AM CDT | Mesoscale Discussion | SPC | Baxter, Boone, Clay, Cleburne, Conway, Craighead and 17 more | 113 min |
| Apr 28, 9:25 AM CDT | Mesoscale Discussion | SPC | Carroll, Crawford, Madison, Washington | 65 min |
| Apr 28, 6:01 PM CDT | Mesoscale Discussion | SPC | Crawford, Franklin, Howard, Logan, Montgomery, Polk and 3 more | 119 min |
| Apr 28, 9:33 AM CDT | Tornado Watch | SPC | Christian, Douglas, Howell, Oregon, Ozark, Shannon and 4 more | 4 hr |
| Apr 28, 12:33 PM CDT | Mesoscale Discussion | SPC | Bollinger, Butler, Cape Girardeau, Carter, Madison, Mississippi and 7 more | 57 min |
| Apr 28, 12:40 PM CDT | Severe Thunderstorm Watch | SPC | Bollinger, Butler, Cape Girardeau, Carter, Mississippi, New Madrid and 4 more | 7 hr |
| Apr 28, 3:29 PM CDT | Mesoscale Discussion | SPC | Bollinger, Butler, Cape Girardeau, Mississippi, New Madrid, Scott and 1 more | 91 min |
| Apr 28, 5:25 PM CDT | Mesoscale Discussion | SPC | Mississippi | 2 hr |
Nearby
Mesoscale Discussions in Missouri, 2021Mesoscale Discussions in Arkansas, 2021Every mesoscale discussion in 2021
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.