We’re tracking a new and developing storm, which will bring rain and severe storms to some portions of the Eastern US. A cut-off low, which is an upper-level low broken off from the jet stream, will form a surface low on Saturday over the Southern Plains. It’s this slow-moving low pressure that will be responsible for bring rain to millions in the East. This storm will also bring snow to portions of the Rocky Mountains Friday into Saturday. Over a foot of snow will fall in some of the mountain peaks.
On Friday into Friday night, the marginal risk for severe weather exists for eastern New Mexico into extreme-West Texas. Large hail and damaging winds of up to 60 mph are the main threats associated with the storms that develop, but a couple isolated tornadoes could not be ruled out based on the change in wind direction by height. Showers and storms will develop ahead of a dry line, which will be moving towards the east during the morning hours in eastern New Mexico. Then in the afternoon, those storms will move into portions of West Texas, especially the Panhandle. There may be some discrete supercell thunderstorms that form along this developing line of storms, which may produce a tornado. The threat for severe storms will persist, mainly in the Texas Panhandle, during the first half of the night, then the threat will diminish as the rain becomes widespread and moves east with this developing storm system.
In terms of the rain with this storm, rain showers will develop during the morning hours from western South Dakota through western Oklahoma and the Front Range of Colorado. Then as the day progresses, the rain will become much more widespread. This will be a light rain, so most locations will receive less than one inch. By the evening hours, rain will be affecting much of South Dakota, Nebraska, Kansas, and portions of Oklahoma. Rain showers may also extend into portions of Minnesota and Iowa. This rain will provide much-needed relief not only to the areas experiencing a terrible drought, but for the areas where wildfires continue to occur. Then overnight Friday, rain will persist across portions of the Northern Plains, including South Dakota and Nebraska. Rain showers and isolated thunderstorms will also extend from southern Minnesota through Iowa, western Missouri, portions of Kansas and Oklahoma, and into north-central Texas. Spotty showers and storms may form ahead of this main batch of rain in Arkansas, Louisiana, and eastern Texas.
Now on Saturday, the threat for severe weather will shift to the east. The threat is low for severe storms, but isolated to scattered strong storms are still expected. All threats for severe weather will be present: large hail, damaging winds, and a few tornadoes. Areas at risk include eastern Texas and southern Louisiana. A large batch of heavy thunderstorms will move into eastern Texas during the afternoon hours, then into southern Louisiana during the evening and overnight hours.
For the rest of the region, rain will be the story. Passing rain showers will be around across much of the Midwest while a steadier rain affects parts of Oklahoma, Kansas, Arkansas, and Missouri. Then overnight Saturday, the rain will move into the Mid and Lower Mississippi River Valleys. Rain showers may also move into portions of the Southeast and Gulf coast. Heavier rain can be expected in the ArkLaTex region into the Mississippi Valley, and that leads to the risk for some flooding. Flash flooding as well as river flooding is possible. Some of the river gauges in this region remain in minor to moderate flood stage due to previous heavy rain events.
On Sunday, spotty severe storms remain possible as the low pressure slowly moves east, but rain will be the bigger story with this storm system. Heavy rain is possible in the Tennessee River Valley, which may pose the risk for flooding. Otherwise, rain and thunderstorms are projected to fall at times from the western Ohio River Valley through the Gulf Coast and into Georgia, South Carolina, and Georgia. As we get into Sunday night, the low pressure will begin to stall, and this storm will bring a light to moderate rain to areas that are in a drought, which includes portions of the Southeast. Rain is likely Sunday night across much of the Southeast, Tennessee Valley, and Florida.
By Monday, this storm will remain over the Southeast while weakening. Therefore, more rain, heavy at times, is forecast to fall across similar areas as Sunday night.
Then Tuesday into Wednesday, this storm will move offshore while moving up the East Coast, thus bringing rain to the Mid-Atlantic and Northeast.