Alert archive / Mississippi / Mesoscale Discussions in 2016
Mesoscale Discussion 474
The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2016, 1:34 PM CDT for 12 counties in Alabama; 38 counties in Mississippi. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 27, 2016, 1:34 PM CDT (18:34 UTC)
- Expired
- Apr 27, 2016, 4:00 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 50 counties
Baldwin County, AL, Choctaw County, AL, Clarke County, AL, Greene County, AL, Hale County, AL, Lamar County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Pickens County, AL, Sumter County, AL, Washington County, AL, Attala County, MS, Calhoun County, MS, Chickasaw County, MS, Choctaw County, MS, Clarke County, MS, Clay County, MS, Covington County, MS, Forrest County, MS, George County, MS, Greene County, MS, Grenada County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jasper County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Leake County, MS, Lee County, MS, Lowndes County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Pearl River County, MS, Perry County, MS, Pontotoc County, MS, Scott County, MS, Smith County, MS, Stone County, MS, Wayne County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS
The radar
The Jackson/Brandon,MS radar (KDGX), 124 km from the middle of the area, began a volume at 18:33 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
Jackson, MS (KJAN), launched 12:00Z, 6.6 hours before the alert went out and 134 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
- 705 J/kg
- Mixed-layer CIN
- -127 J/kg
- Mixed-layer LCL
- 593 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 94 m²/s²
- 0-3 km storm-relative helicity
- 37 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.8
The text
As transmitted.
765
ACUS11 KWNS 271834
SWOMCD
SPC MCD 271834
ALZ000-FLZ000-MSZ000-LAZ000-272100-
MESOSCALE DISCUSSION 0474
NWS STORM PREDICTION CENTER NORMAN OK
0134 PM CDT WED APR 27 2016
AREAS AFFECTED...ERN MS...WRN AL
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 271834Z - 272100Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...AN ISOLATED SEVERE THREAT MAY DEVELOP ACROSS ERN AL AND
WRN AL THIS AFTERNOON. A FEW DAMAGING WIND GUSTS AND HAIL WILL BE
POSSIBLE WITH THE STRONGER THUNDERSTORMS. WW ISSUANCE MAY NEED TO BE
CONSIDERED ACROSS THE REGION.
DISCUSSION...LATEST SFC ANALYSIS SHOWS A CORRIDOR OF LOW-LEVEL
MOISTURE EXTENDING FROM SRN MS NWD ACROSS ERN MS INTO WRN TN...ALONG
WHICH SCATTERED THUNDERSTORMS ARE ONGOING. SFC TEMPS ACROSS ERN MS
AND WRN AL HAVE WARMED TO NEAR 80 F THIS AFTERNOON WHICH IS
CONTRIBUTING TO MODERATE INSTABILITY WITH MLCAPE VALUES ESTIMATED TO
BE IN THE 1000 TO 2000 J/KG RANGE FROM COLUMBUS MS SWD TO THE GULF
COAST. AS INSTABILITY AND LOW-LEVEL LAPSE RATES CONTINUE TO INCREASE
ALONG THIS CORRIDOR WHERE SFC DEWPOINTS ARE IN THE LOWER 70S F AND
DEEP-LAYER SHEAR IS GENERALLY LESS THAN 25 KTS...A FEW DAMAGING WET
DOWNBURSTS ASSOCIATED WITH MULTICELLS WILL BE POSSIBLE.
..BROYLES/CORFIDI.. 04/27/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BMX...MOB...MEG...JAN...LIX...
LAT...LON 30418750 30108842 30028937 30938969 32678968 33708986
34298971 34488863 33758791 31878732 30418750SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 3:28 PM CDT | Mesoscale Discussion | SPC | Colbert, Cullman, Fayette, Franklin, Jefferson, Lauderdale and 6 more | 2 hr |
| Apr 27, 7:30 AM CDT | Mesoscale Discussion | SPC | Adams, Wilkinson | 2 hr |
| Apr 27, 7:54 AM CDT | Severe Thunderstorm Watch | SPC | Adams, Amite, Claiborne, Copiah, Covington, Forrest and 20 more | 7 hr |
Nearby
Mesoscale Discussions in Mississippi, 2016Mesoscale Discussions in Alabama, 2016Every mesoscale discussion in 2016
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.