Threat for overnight severe weather downgraded

Threat for overnight severe weather downgraded

BATON ROUGE, LA (WAFB) - We continue to await a possible round of severe weather here in South Louisiana.

The threat will primarily exist early Sunday morning during the predawn hours.  The Storm Prediction Center (SPC) in Norman, Oklahoma has placed the entire WAFB viewing area under a "Slight" risk for severe weather with their Saturday evening forecast package.  This is a downgrade from an earlier "Enhanced" risk.  A slight risk for severe weather means that while widespread severe weather is not anticipated we can't rule out a couple of strong if not severe t-storms.

Severe weather overnight could come in two rounds.  The first round, which doesn't appear all that likely at this time, would be pre-squall-line T-storms.  The storms could form after a warm front moves through South Louisiana overnight pushing warm, moist air into the region.  These storms would hold the greatest potential for tornadic activity as current wind shear would cause rotation.  The good news is that we have a decent cap to the atmosphere over SE Louisiana which should keep these storms from truly forming.  These pre-squall storms would be possible starting at 2 AM and continuing until the squall-line arrives.

Potential round two of severe weather would come in the form of the squall-line (cluster of strong t-storms moving in the form of a line) mentioned earlier.  This squall-line will be moving in an eastward direction overnight.  We should start to see extreme western sections of the WAFB viewing area affected by this squall-line starting at 4-5 AM.  It should then begin to move into metro Baton Rouge around 6 AM before exiting the viewing area a little after 7 AM.  The squall-line poses the best threat for severe weather.  The primary concern would be damaging straight-line winds in excess of 60 mph.  These winds should not be dismissed as they can often cause damage similar to tornadoes.

A major concern with this event continues to be the timing.  Many people will still be sleeping which highlights the fact of having some way of receiving weather alerts to stay alert to changing weather patterns in your immediate area.  Round 1 could start as early as 2 AM and the threat could remain for severe weather around or shortly after sunrise Sunday.

The potential for seeing heavy, flooding rains has diminished greatly.  The speed of the squall-line should keep most neighborhoods from experiencing the previously forecasted high rainfall totals.  Weather models late Saturday continue to indicate totals at or near 1" for most spots across SE Louisiana and SW Mississippi.  These kinds of totals should be easily handled by ground absorption and city drainage systems.