A slow-moving cold front associated with an area of low pressure in the Great Lakes will be the focus for scattered strong to severe thunderstorms across the Lower Mississippi River Valley on Saturday, December 9th.
As the cold front slowly pushes from west to east across the region, a secondary area of low pressure is expected to develop along the front and accelerate its eastward movement from the Southern Plains into the Mid-South from Saturday morning to Saturday evening.
A mostly-messy corridor of shower and thunderstorm activity is expected to result, with at least a low risk for an isolated tornado or two and scattered wind gusts over 60 MPH. Large hail may also occur with early storm development. The risk for severe weather will initially be highest west of the Mississippi River on Saturday morning, shifting east of the river on Saturday afternoon and evening.
Storm Chasing Notes: A lot of questions remain surrounding coverage and intensity of severe storms on Saturday, and given the expected messy and disorganized nature the “photogenic-ness” and chaseability of Saturday’s storms is expected to be quite low for any Southern U.S. storm chasers hoping for a pre-holiday chase.
Here's what the experts are saying ahead of Saturday's storms:
Storm Prediction Center Day 2 Outlook:
STRONG SOUTHWESTERLY DEEP-LAYER SHEAR WILL BE FAVORABLE FOR SUPERCELLS PRODUCING LARGE HAIL, ESPECIALLY WHERE FLOW CAN BE SEMI-ORTHOGONAL TO THE FRONT ACROSS EAST TX AND THE SABINE VALLEY. A CLUSTERED CONVECTIVE MODESHOULD DOMINATE TO THE EAST ACROSS THE MID-SOUTH OWING TO ORIENTATION OF CONVECTIVE DEVELOPMENT NEAR/AHEAD OF THE COLD FRONT MORE CLOSELY PARALLELING THE DEEP-LAYER SHEAR VECTOR. BUT EMBEDDED SUPERCELLS ARE EXPECTED AS WELL, WITH LOW-LEVEL HODOGRAPHSADEQUATELY ENLARGED FOR A FEW TORNADOES. Shreveport, Louisiana NWS Area Forecast Discussion:
THE MAIN FOCUS IN THE EXTENDED
WILL BE THE STRONG STORM SYSTEM MOVING ACROSS THE AREA SATURDAY
THROUGH SATURDAY NIGHT. BY SATURDAY AFTERNOON THE COLD FRONT WILL BE POISED ACROSS THE DELTA, WITH INCREASING DEVELOPMENT OF
SHOWERS/STORMS. THE FRONT WILL MOVE ACROSS THE AREA DURING THE
AFTERNOON THROUGH THE EVENING HOURS, BEFORE MOVING EAST OF THE
AREA AFTER MIDNIGHT. WITH GOOD INSTABILITY, STEEP MID LEVEL LAPSE RATES AND DECENT SHEAR, SEVERE STORMS ARE LIKELY. INITIALLY THERE COULD BE A FEW MORE CELLULAR STORMS, BUT AS THE DAY PROGRESSES,
EXPECT THE STORMS TO BECOME MORE LINEAR AS THE LINE OF STORMS
PROGRESSES ACROSS THE AREA. EXPECT THE PRIMARY RISK TO BE DAMAGING WIND GUSTS AND LARGE HAIL, BUT A FEW TORNADOES WILL BE POSSIBLE.
A SLIGHT RISK IS ALREADY IN EFFECT FOR MOST OF THE AREA, WITH A
MARGINAL RISK FOR THE EAST AND SOUTHEAST.