Longwave troughs stretched from Southeast Canada southwest to Eastern Texas, while widespread ridging blanketed most of the Desert Southwest.
At the time of this writing, a surface low was centered on Coastal Mississippi, and a cold front was moving through our southeast counties and into the state.
Another cold front was identified that moved northeastward across eastern Tennessee from Jackson, Mississippi.
This secondary cold front served as a boundary between cooler temperatures across our central counties and colder temperatures that reached the low 30s and 40s in the northwest of the state.
As the deep longwave trough moves eastward, it will pass over the Arklatex region during the early afternoon and then travel through the Mid-South region by the evening, passing across our area by midnight. As the system moves northeastward through the Carolinas in the early morning hours of Monday, a closed low aloft seems to be developing inside the trough's interior.
As a wave of low pressure travels northeast from the Central Gulf Coast area into the Southeast Alabama Wiregrass region this afternoon, the present cold front across our southeast counties will begin to weaken.
This evening in South-Central Georgia, the surface low will be positioned advantageously to the southeast of the powerful trough and developing closed low, providing a favorable opportunity for development.
Because of the rapidly deepening cyclogenesis that will occur, strengthening northwest winds will result, which will effectively pull the secondary cold front across our northwest through the forecast area overnight, resulting in strong low-level cold advection and temperatures that will plummet to below freezing across much of our northwest and north-central counties by 4 a.m.
The strong climb will be supported by steep lapse rates beneath the cold core low, which will result in increased precipitation rates as a consequence.
Rainfall values will stay at or above an inch over the region into the early evening, with values dropping to around a half of an inch across the west after 6 pm and about a quarter of an inch across the east after 10 pm.
The shallow moisture content at the lower level will remain for a longer period despite the general decrease in moisture throughout the column.
This shallow moisture content will sustain precipitation from this evening into the early morning hours on Monday.