ACUS01 KWNS 051539
SWODY1
SPC AC 051538

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0938 AM CST Sun Jan 05 2025

Valid 051630Z - 061200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE LOWER MISSISSIPPI VALLEY...

...SUMMARY...
Severe thunderstorms are expected this afternoon and evening from
the Sabine River Valley into the Mid-South and central Gulf Coast
states. Tornadoes and scattered severe/damaging winds should be the
primary threats. A couple of strong tornadoes may also occur.

...Synopsis...
Water-vapor imagery this morning shows a mid- to upper-level trough
over the central U.S.  A powerful mid-level shortwave trough will
move through the base of the larger-scale trough over OK and move
into the lower OH Valley/Mid South with an accompanying 100-kt 500mb
speed max over the central Gulf Coast states by early Monday
morning.  In the low levels, a cyclone over northeast OK will
develop east into the KY/TN border region late.  An accompanying
cold front over the southern Great Plains this morning will sweep
southeastward into the lower MS Valley by late afternoon before
moving into the southern Appalachians and FL Panhandle by daybreak
Monday.

...East Texas into the Mid-South and central Gulf Coast states...
A weak thunderstorm band this morning from western AR into northeast
TX has developed immediately ahead of the front in response to
intensifying large-scale ascent and strong low-level warm/moist
advection.  Despite a pronounced capping inversion noted on the 12z
Shreveport, LA raob, additional moistening/destabilization and
ascent will promote additional storm development late this morning
into the afternoon.  Model guidance shows only weak elevated
instability over northeast AR into western TN, but larger buoyancy
will exist over southern AR/LA/east TX where 500-1000 J/kg MLCAPE is
expected.  Model forecast soundings show enlarged hodographs across
the surface-based warm sector with 0-1 km SRH generally in the
250-500 m2/s2 range.  It appears a mix of pre-frontal and frontal
thunderstorm activity will evolve late this morning through the
early evening.  The stronger and more persistent updrafts ahead of
the front will likely become supercellular and pose a risk for
tornadoes, including the possibility for strong tornadoes.  Damaging
gusts and perhaps some tornado risk will likely evolve with the
frontal convection (QLCS) as it gradually intensifies this afternoon
and likely persists across the coastal plain through tonight.  Have
increased low-severe probabilities farther east into southeast AL
where model guidance shows weak destabilization prior to frontal
passage late tonight.

..Smith/Weinman.. 01/05/2025

$$

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