1/13 – Rob Knight’s “Sunny & Cool” Thursday Afternoon Forecast
Today will be a quiet weather day locally while high-pressure to the west shapes the forecast. Any significant moisture return isn’t likely to occur until sometime Friday night, so dry weather will be the rule today and tomorrow with temperatures moderating.
Saturday into early Sunday, a strengthening storm system is expected to across the area, which will bring the likelihood of rain to the area. Southerly surface winds ahead of the front Saturday will continue warm air and moisture advection into the area, which will produce some instability. Numerous showers will be possible Saturday into early Sunday as this front moves through. Some low- topped thunderstorms and gusty sub-severe (30-60 mph) winds can’t be ruled out totally with this system, but given the lack of instability, It won’t be the main concern.
Winds behind the low-pressure will be northwesterly at the surface, which will pull in much drier and colder air into the region. As the upper level trough tracks deeper south and east, northern portions of our area will be caught briefly on the backside of the low with strong cold air advection Sunday morning. Clouds will be lingering over the area on Sunday morning, which will allow for some moisture at the low levels to linger as well. Temperatures on Sunday morning will struggle to warm up and may struggle to get out of the 30s prior to noon. This, combined with strong cold air advection on the backside of the low and low level moisture availability means that it may (emphasis on may) be possible to see a few snow flurries on Sunday morning in the SW MS counties through Hattiesburg.
The rest of the day Sunday, the low moves off the eastern coast of the US and cold air advection will continue to push southward into the region. If clouds linger all day Sunday, current forecast high temperatures may be rather optimistic, with 40s more likely. Lows on Monday morning as a result will be quite chilly with temperatures in the lower 30s. Upper level ridging will be the primary upper level pattern Monday. Northerly surface winds will help to enhance cold air advection and dry air advection into the area.