During the day on Wednesday, a wave of low pressure over the Central Gulf Coast will travel into the southern Mid-Atlantic, followed by a second wave of low pressure over the Central Gulf Coast during the day on Thursday.
Showers and thunderstorms will be triggered along the Central Gulf Coast by the accompanying front, with some thunderstorms having the potential to be severe.
So the SPC has issued a Slight Risk of severe thunderstorms for portions of the Central Gulf Coast until Wednesday AM.
The dangers linked with these thunderstorms include frequent lightning, intense thunderstorm wind gusts, hail, and a few tornadoes, among other things. Furthermore, heavy rain associated with these thunderstorms can cause localized flash floods in places that see quick runoff as a result of the heavy rain.
Thunderstorms in the Southeast
Due to the accompanying front producing showers and thunderstorms, the danger of severe thunderstorms is moving eastward and towards the Southeast. Consequently, the SPC has issued a Slight Risk of severe thunderstorms for areas of the Southeast from Wednesday morning through Thursday morning.
The dangers linked with these thunderstorms include frequent lightning, intense thunderstorm wind gusts, hail, and a few tornadoes, among other things. In addition, the potential of excessive rainfall is moving eastward with the front as the accompanying heavy rain causes isolated regions of flash flooding, which will impact areas that suffer quick runoff in the presence of heavy rain.
Snow in the Northeast
As for the rest of the week, an area of low pressure stretching from the Upper Great Lakes to the Central Rockies will travel eastward to the Northeast/Mid-Atlantic Coast by Friday evening.
Light snow may fall over portions of the Upper Great Lakes until Thursday morning as a result of the front.
As a result of the front's interaction with an area of low pressure over the southern Mid-Atlantic, two to four inches of snow will fall throughout areas of the interior Northeast on Wednesday.
Showers in the Northwest
Aside from that, upper-level energy moving through the Pacific Northwest will push the western edge of the front southward across the Great Basin and into southern Colorado by Thursday, causing it to proceed into the Southwest and Southern Rockies by Friday.
In the early morning hours of Tuesday, the energy will create coastal rain and light snow across sections of the Pacific Northwest and Northern Rockies, which will spread to areas of the Great Basin and Central Rockies on Wednesday.
The rain will finish in the Northwest by the late afternoon of Wednesday, according to forecasts. Higher altitudes of the Great Basin and Central Rockies will see a lot of snow, especially in the afternoon.
Additionally, light to moderate snow may fall across sections of the Central Plains on Wednesday, according to the National Weather Service.
The Northern Rockies/Northern/Central High Plains will have freezing temperatures in addition to snow, with some sites experiencing record or tied for record low temperatures on Wednesday and Thursday mornings. As a wave of low pressure moves out of the Central Rockies and into the Middle Mississippi Valley on Thursday, heavy snow will fall throughout the Central Plains and into the Mississippi Valley.
As the storm passes out of the Rockies, gusty winds, low humidity, and dry fuels have all contributed to the formation of an area of Critical Fire Weather across the Southern Rockies and into the Southern High Plains on Wednesday.