As a record-breaking late season blizzard departs after dumping one to two feet of snow in the north-central United States, a new storm system threatens to deliver the next weather assault.
The southern storm this weekend and the central U.S. cyclone that came before have both been fueled by a very active jet stream pattern that may spur additional storminess next week.
This weekend’s severe weather threat
Unlike the blizzard that just passed — which relied on a feed of frigid air from the Arctic, the weekend storm will draw from very warm, humid air from the Gulf of Mexico. Severe weather is possible Saturday from East Texas across the Mid-South, and then Sunday from the northern Gulf Coast into the Ohio Valley and the Southern Appalachians.
Strong and turning winds aloft appear to be ready to mingle with unstable air near the ground to spin up a regional tornado outbreak across parts of northern Louisiana, Arkansas, Texas and Mississippi on Saturday. Although these are the likely hot spots, some shift in the zone of highest risk is still possible.
DANGEROUS DAY ahead on Saturday across most of the state of Louisiana, far eastern TX into southern AR, marching across the MS River into western MS late in the day. Shows here are the HRRR forecast significant #tornado parameter, forecast radar for mid afternoon @accuweather pic.twitter.com/ZwucSYPdpS
— Reed Timmer (@ReedTimmerAccu) April 12, 2019
The National Weather Service Storm Prediction Center has declared a moderate risk of severe storms for only the second time this year. At level 4 out of 5, it is the second highest risk level on the center’s 0 to 5 scale. The issuance of a moderate risk threat this early in the spring is historically unusual and points to the confidence in severity of storms expected.
“Along with locally damaging winds and hail, strong tornadoes may also occur, within a few of the most intense storms,” the center wrote in its outlook for Saturday issued early Friday morning.
Some population centers in the moderate risk area include Shreveport, La., as well as Greenville and Vicksburg, Miss.
While the risk for strong tornadoes is likely to be concentrated in and near the area at moderate risk, places within the enhanced (level 3 out of 5) or slight (level 2 out of 5) zones, including Dallas and New Orleans, are also advised to stay tuned and have a plan if severe weather threatens. Storms are likely to move speedily, so time to act upon warning may be short.
Today's trough lifts, which means no crashing front into the Gulf, since the surface high generally follows the trough. Also, trailing upper trough renews lee surface troughing in the lee of the southern Rockies tomorrow (1/2) pic.twitter.com/6DNgTNXyaw
— Jeff Frame (@VORTEXJeff) April 12, 2019
The large wave in the jet stream that is responsible for the storms heads farther east on Sunday, when additional severe storms will probably occur in parts of the Ohio Valley into the Appalachians and down to Florida. Although wind damage may be the primary threat, more tornadoes are possible as well.
Believe it or not, the blizzard that just hit the Plains and Midwest is paving the way for this severe weather event. Because this first storm is lifting north into Canada rather than dragging a cold front toward the Gulf Coast, moisture over the South is able to remain in place rather than being swept away.
A historic blizzard winds down
Widespread deep powder has been left in the wake of the blizzard. In some places, drifts are as high as five or more feet!
Much of South Dakota picked up one to two feet of snow. Numerous totals approaching two feet were reported in south-central parts of the state to the south of Interstate 90. The highest totals include White River, with 26 inches, and Ideal, with 24.
In east-central South Dakota, Huron picked up 18 inches over Wednesday and Thursday, and will add to the total somewhat when Friday’s amounts are added.
The 18 inches was the most over two days in April or later in Huron. It was also a top-10 snowstorm there for any month, and the snowiest two days since March 2002. Similar numbers, up to about two feet, came in from northeast parts of the state and into western Minnesota.
A long duration satellite loop of the major spring storm today as seen on #GOESEast #ndwx @NOAASatellites pic.twitter.com/a5X4FFkkU6
— NWS Bismarck (@NWSBismarck) April 12, 2019
In addition to threatening all-time snowstorm records in areas where totals neared and surpassed two feet, a bunch of daily snowfall records were surpassed during the event.
A small sample includes Mitchell, S.D., where 15 inches demolished the old record of four inches. Other places that saw daily records include Fargo and Grand Forks in North Dakota. Records were spread across multiple states, including sites such as International Falls in Minn.; Alpena, Mich; and Cheyenne, Wyo.
Below are the top totals in states that saw at least a foot of snow.
- Terry Peak, S.D.: 30 inches
- Lander, Wyo.: 27 inches
- Madison, Minn.: 20 inches
- Havana, N.D.: 17.5 inches
- Eli, Neb.: 16 inches
- Winter Park, Colo.: 15 inches
- Albion, Mont.: 13 inches
- Townsend, Wis.: 12 inches
More next week?
While it’s a bit too far off to say much with certainty, it does appear that another storm system will swing through the central United States next week.
Indications are that it may take a somewhat similar track to the weekend event. If that’s the case, it would again seem that wintry weather will take a back seat to other spring weather, such as severe weather and flooding.
With parts of the Mississippi River Valley and surrounding forecast to pick up as much as half a foot of rain through the middle of next week, and snowmelt coming from the recent blizzard, it would seem that flooding issues will increase again over the next week or two.