Mesoscale Discussion 89

Issued

Jan 21, 2017, 9:19 AM CST (15:19 UTC)

Expired

Jan 21, 2017, 10:45 AM CST

In force

86 min

Issued by

the Storm Prediction Center

The Ft Rucker radar (KEOX), 47 km from the middle of the area, began a volume at 15:23 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.

• Tornado Watch 14Jan 21, 1:10 PM CST

867 
ACUS11 KWNS 211519
SWOMCD
SPC MCD 211519 
GAZ000-FLZ000-ALZ000-211645-

Mesoscale Discussion 0089
NWS Storm Prediction Center Norman OK
0919 AM CST Sat Jan 21 2017

Areas affected...Portions of GA...southeastern AL...the FL Panhandle

Concerning...Tornado Watch 11...12...

Valid 211519Z - 211645Z

The severe weather threat for Tornado Watch 11, 12 continues.

SUMMARY...The risk for severe thunderstorms capable of damaging
winds and tornadoes continues across Tornado Watches 11 and 12.

DISCUSSION...A squall line extending from west-central GA through
the western FL Panhandle will continue progressing eastward during
the next several hours. A moist boundary layer characterized by
surface dewpoints in the middle 60s to around 70F continues to
develop northward ahead of this activity, and south of a warm front
analyzed from southeast AL to south-central GA. With pockets of
modest diurnal heating, limited gains in buoyancy will occur, which
should allow the squall line to be maintained eastward given ample
low-level and deep shear. With deep shear vectors oriented obliquely
to the line, rotating convective elements may continue to evolve
within embedded LEWP structures and line breaks, where pockets of
wind-damage and tornado potential will be enhanced. The severe risk
will decrease behind the convective line until later this afternoon
into tonight.

Meanwhile, a warm-advection plume branches from the northern extent
of the squall line through north-central GA and into east-central
GA. Northward fluxes of low-level moisture and related
destabilization along the southern fringes of the
warm-advection-enhanced precipitation shield will maintain a risk
for deeper convective elements/occasional supercell structures
across parts of central GA and vicinity. While inflow parcels may be
only very marginally buoyant, strong low-level shear may offer some
tornado potential with this activity.

..Cohen.. 01/21/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FFC...TAE...BMX...MOB...

LAT...LON   30438705 31768563 33368462 33538351 32728273 31368325
            30098489 30068601 30438705

Mesoscale Discussions in Georgia, 2017Mesoscale Discussions in Florida, 2017Mesoscale Discussions in Alabama, 2017Every mesoscale discussion in 2017

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.