Good morning everyone! The only main threat to discuss for today is the fog that has developed across portions of the Dakotas. Dense Fog Advisories are in effect for central and northwestern ND for these issues with fog, which are in effect until 11am CDT. However, areas of fog can be noted in additional portions of the Dakotas. Shown below are model simulated areas that should be experiencing fog at this time. Temperatures across the region are well below freezing, so any fog that has developed across the Dakotas will lead to slick spots. The fog will gradually erode with time today, but definitely note any slick spots if traveling. Our main discussion will cover the upcoming significant winter storm that will impact the region. Winter Storm Watches have now been issued for southwestern SD, but anticipate more of these to be issued through the day across additional portions of the Dakotas and northern MN. Also, we wouldn’t be surprised to see some Flood Watches issued for southeastern areas given the impending dose of heavier rain over the deep snowpack.
While the fog threat will be minimal by mid-afternoon, additional moisture return from the south and temperatures warming into the 20s overnight for some locations over a still very cold snowpack and then 30s Tuesday morning will allow for the redevelopment of fog, first in the eastern Dakotas and southwestern MN that spreads northward to encompass central ND and portions of northern MN as well. As is the case with this morning, temperatures will be below freezing for many so slick spots will be a concern. Even if temperatures rise above freezing in areas experiencing fog tomorrow, slick spots will remain due to the cold ground temperatures. A freezing mist/drizzle accompanying areas of fog will be possible, but more likely in eastern SD into MN.
The system that will bring significant impacts to the Northern Plains mid-late work week will get its beginnings as early as early Tuesday afternoon mainly in southern MN where areas of light shower activity in drizzle will be most pronounced. This will lift northeastward through the afternoon and bring the threat to the rest of MN. We can’t rule out some freezing drizzle as well where temperatures remain at freezing, but also given the colder surfaces. Areas of mist/drizzle will remain a possibility overnight in MN that also works into southern SD as the night progresses. By Wednesday morning, increased precipitation coverage will be expected across the southern tier of SD (freezing rain and snow in southwest and rain in southeast).
The storm system that is expected to bring a dangerous event to the Northern Plains will be strengthening significantly across the Central Plains during the day Wednesday. Shown below are climatological percentiles for the barometric pressure of the storm. Near record low pressure is expected to engulf the state of KS (below the 5th percentile in pressure – very low pressure). This wave will lift northeastward into Thursday and pack a punch with heavy snow and blizzard conditions in the Dakotas and initially a heavy rain threat that could lead to areal flooding for southeastern SD into central/southern MN as well.
The main course of this system will lift northeastward into the region during the day Wednesday. Watch for areas of moderate to perhaps heavy rain at times work into southeastern SD and southern MN Wednesday morning that lifts northward through the day. Colder air to the west will allow for heavy snow to develop across the western two-thirds of SD during this time, then into southern/eastern (especially southeast) ND and northwestern MN Wednesday night. Precipitation coverage will be widespread across the forecast area with blizzard conditions across the Dakotas given a very tight pressure gradient and the snow falling. Precipitation will start to pull east during the day Thursday, so areas that started off with rain can transition to backside snow showers during this time into Thursday night. Watch for the bulk of the backside snows to lift to the east out of the Dakotas by midnight Thursday night and then MN by Friday morning.
Wind forecast over the next four days: Expect a calmer day in the wind department today with an uptick in winds Tuesday but especially into Wednesday as our next potent storm system lifts towards the region. Winds will be particularly strong with this mid-week disturbance (very deep low pressure system in the Central Plains which could near barometric pressure records), so gusts approaching 55mph will be common. As the low lifts towards the Great Lakes Thursday, winds will remain strong and gusting to 55mph. Areas that pick up heavy snow with this disturbance (western two-thirds of SD and southeastern ND) will likely observe blizzard conditions with whiteout conditions and blowing/drifting snow.
Shown below is a risk map for the upcoming snowstorm: Models are in very good agreement that the areas in the high risk area are in for a heavy thump of snow (6-12″+ looking more likely) while those in the medium risk area will still be at risk for a decent thump of snow. Snowfall amounts of 18″ will be possible, but likely will be more confined to localized pockets in southwestern SD. This system will be very powerful as its low pressure center lifts through the Central Plains (also strengthening), resulting in very intense wind gusts of 55mph for many locations. The event is still a couple days away from occurring so subtle changes will be possible. Given the dynamics at hand, this is not a storm to take lightly as a full-blown blizzard is expected where it snows a decent amount, but regardless of the snow it will be windy area-wide.
Total precipitation through the next 7 days: The bulk of what comes through the upcoming week is with this one powerful system mid-work week. Precipitation will be in abundance with this wave as a majority of SD, southeastern ND into MN will receive 1″ of liquid or more. The heaviest of the precipitation will be located in southern/eastern SD where 1.5-3″ of liquid will be likely. The rains will be heavy at times in eastern SD into central/southern MN, so areal flooding will be a threat due to ground temperatures below freezing not allowing the ground to take in the moisture as well as the deep snowpack partially melting.
There is light at the end of the tunnel as our weather pattern turns quite inactive with the passage of this storm system. Shown below is the 5-day precipitation anomaly following the end of precipitation Friday morning. An upper-level trough will dig into the Eastern US and shunt the enhanced precipitation risks well south and east of the region. Dry, northwest flow will develop with very limited moisture. A few very weak waves of precipitation will be possible, with one far northeast this weekend. However, it will definitely be a huge turnaround to what we’ve experienced over the last couple of months with some drying likely occurring, but colder temperatures remaining that will be more pronounced with the remaining snowpack.
Temperatures over the next four days: Cooler daytime highs will remain today with temperatures below freezing. However, watch for the warmest air in quite some time lift northward into the region Tuesday into Wednesday, especially eastern areas, with the incoming storm system. High temperatures in MN will warm above freezing and could even rise into the 40s during the day Wednesday. It will remain cold enough (<32ºF) for snow in most of the Dakotas and far northern MN Wednesday into Thursday.
High/low temperatures over the next 10 days for Fargo, Bismarck, Minneapolis and Sioux Falls:
If you have any questions do not hesitate to reach out! Have a great day!