Alert archive / Alabama / Mesoscale Discussions in 2016

Mesoscale Discussion 85

February 3, 20167 counties in Alabama

The Storm Prediction Center issued this mesoscale discussion at Feb 3, 2016, 1:30 AM CST for 7 counties in Alabama. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Feb 3, 2016, 1:30 AM CST (07:30 UTC)
Expired
Feb 3, 2016, 2:30 AM CST
In force
60 min
Issued by
the Storm Prediction Center

Counties Calhoun County, AL, Clay County, AL, Coosa County, AL, Elmore County, AL, Macon County, AL, Talladega County, AL, Tallapoosa County, AL

The radar

The Maxwell AFB radar (KMXX), 63 km from the middle of the area, began a volume at 07:32 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

Birmingham, AL (KBMX), launched 00:00Z, 7.5 hours before the alert went out and 74 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.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 00:00Z on 2016-02-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 313 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 00:00Z on 2016-02-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 371 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
313 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
765 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
371 m²/s²
0-3 km storm-relative helicity
518 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.2

Open this sounding in Storm Lab

The text

As transmitted.

554 
ACUS11 KWNS 030731
SWOMCD
SPC MCD 030730 
ALZ000-030830-

MESOSCALE DISCUSSION 0085
NWS STORM PREDICTION CENTER NORMAN OK
0130 AM CST WED FEB 03 2016

AREAS AFFECTED...ERN AL THROUGH EXTREME

CONCERNING...TORNADO WATCH 13...

VALID 030730Z - 030830Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 13 CONTINUES.

SUMMARY...LINE OF STORMS WILL REMAIN CAPABLE OF PRODUCING SPORADIC
STRONG TO DAMAGING GUSTS AND A COUPLE OF TORNADOES THROUGH THE EARLY
MORNING AS IT CONTINUES THROUGH ERN AL NEXT COUPLE HOURS. STORMS
WILL BEGIN MOVING EAST OF WW 13 BY 08Z...AND THIS WW CAN BE LOCALLY
EXTENDED FARTHER EAST ANOTHER COUPLE HOURS AS NEEDED.

DISCUSSION...LINE OF STORMS FROM NERN AL SWWD THROUGH CNTRL AL IS
MOVING EAST AT AROUND 35 KT. THE STORMS WILL APPROACH THE ERN END OF
WW 13 BY 08Z. THE DOWNSTREAM ATMOSPHERE IS ONLY MARGINALLY UNSTABLE
WITH WEAK LOW-MID LEVEL LAPSE RATES...AND THE WEAK THERMODYNAMIC
ENVIRONMENT SHOULD CONTINUE TO SERVE AS A LIMITING FACTOR FOR A MORE
WIDESPREAD AND ROBUST SEVERE THREAT. NEVERTHELESS...A STRONG LLJ
REMAINS IN PLACE ALONG WITH 60 KT 0-6 KM SHEAR. THUS OCCASIONAL
EMBEDDED MESO-VORTICES AND BOWING SEGMENTS WILL CONTINUE TO
OCCUR...POSING AT LEAST A MODEST THREAT FOR A FEW STRONG TO DAMAGING
WIND GUSTS AND A COUPLE OF TORNADOES THROUGH THE EARLY MORNING.

..DIAL.. 02/03/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...BMX...

LAT...LON   32308623 32868649 33538641 33948613 33968571 33568561
            32868548 32388567 32308623

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 2, 6:52 PM CSTTornado WatchSPCBaldwin, Choctaw, Clarke, Mobile, Monroe, Washington and 1 more8 hr
Feb 2, 8:50 PM CSTMesoscale DiscussionSPCBibb, Blount, Chilton, Colbert, Cullman, Fayette and 22 more55 min
Feb 2, 9:59 PM CSTTornado WatchSPCAutauga, Bibb, Chilton, Clay, Coosa, Dallas and 14 more6 hr
Feb 2, 10:23 PM CSTMesoscale DiscussionSPCBaldwin, Choctaw, Clarke, Mobile, Monroe, Washington and 1 more2 hr

Nearby

Mesoscale 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.