High Wind Warnings continue today across parts of the Upper Mississippi Valley & Upper Midwest. Blizzard warnings in place across parts of the Midwest and Upper Mississippi Valley region today for blowing and drifting snow due to those strong winds across the Upper Mississippi Valley. Snowfall to continue across the region as this system slow progresses to the east into the Northeast.
A slow-moving vertically stacked low-pressure system will gradually eject to the east through tonight as a shortwave trough helps push this system off bringing an end to the snowfall across the Midwest. As the upper low begins to fill and pivot eastward, the primary surface low will weaken as it dives south towards Missouri, while secondary low pressure develops across MI near the triple point. Each of these surface waves will bring moderate snowfall to the region.
With the primary low, periodic vorticity lobes spinning around the the closed feature will provide ascent for showery snow conditions across the region. As these features dive southward, they will enhance snowfall in a narrow band, likely from southern MN through central IA and into central MO. While the heaviest snowfall is was expected earlier this morning over the overnight hours. Periods of moderate to at times heavy snow where this axis lasts the longest could produce additional several inches of snowfall with rates potentially reaching 1"/hr for brief periods today. WPC probabilities for 4 inches are as high as 30%.
Further to the northeast associated with the secondary wave of low pressure moving across MI, an additional band of moderate to heavy snow will develop aided by additional vorticity lobes wrapping around the low, near moist adiabatic lapse rates through the column, and ascent in the region. Where this band pivots the longest, WPC probabilities indicate a 30-40% chance for 4 inches of snow across the northern L.P. of MI.
As this system ejects out of the Midwest, it will advect slowly eastward towards the NW. Vorticity lobes will continue to rotate around the low, with the primary vort lobe beneath the left front quadrant of a 130kt shared energy area of the Subtropical Jet and the Polar Front Jet interacting with the low-level baroclinic zone and a triple point extending from the Midwest surface low to drive secondary cyclogenesis near the Mid-Atlantic coast which will then lift northeast into Maine. This surface low will be accompanied by robust WAA ahead of it, increasing precipitable water which will spread and expand precipitation northward from the Central Appalachians into Canada. As the low develops and ascent becomes more robust through intense upper diffluence aloft and the more pronounced warm/moist advection.
In the higher terrain of upstate NY, VT, NH, and ME, intense ascent with some upslope enhancement will continue, and heavy snow is likely to persist much of the day with snow rates of 1-2"/hr possible at times. Also periods of Lake Effect Snow off Lake Erie and Ontario is possible behind this system as winds switch to a westward flow behind the low increasing fetch across the lakes. There are high probabilities for more than 4" in the favored snow zones in WV, as well as downwind of these two lakes.
Additionally, the closed low moving across the Ohio Valley and into the northeast will create an environment supportive of widespread snow showers across a large portion of the east. While accumulations are likely to be light, any location across the OH
Valley, Mid-Atlantic, and much of the Appalachians could see briefly heavy snow as increased instability interacts with periods of low-level frontogenesis band and moist low-level lapse rates.
A mid-level to upper-level ridge will retreat inland early Sunday as it gets
replaced by a shortwave trough and accompanying height falls into the
Pacific Northwest. This feature will be driven eastward by a modest but expanding Pacific jet streak which will spread moisture inland while also placing the diffluent RRQ atop the region. Moist advection from the Pacific jet in the presence of deep-layer ascent will drive snowfall in the terrain from the WA Cascades and possibly reaching the Front Range by the end of Sunday. The highest snowfall is likely in the WA Cascades and into the Northern Rockies. WPC probabilities for 6 inches are high in these areas, with generally less than 6 inches expected elsewhere.
High Wind Warnings remain in effect as a steep pressure gradient at the surface and a strong contour gradient aloft created by an intense low pressure over the Midwest and a strong area of high pressure over the Pacific Northwest. The low to mid-level winds are mixing down the surface creating some intense non-convective wind gusts across the region today.
The National Weather Service in Pueblo has issued a
* Dust Storm Warning for...
Prowers County in southeastern Colorado...
Baca County in southeastern Colorado...
Kiowa County in southeastern Colorado...
Bent County in southeastern Colorado...
* Until 1115 AM MST.
* At 950 AM MST, Several bands of blowing dust were located over
Bent, Kiowa, Prowers and Bent counties. This dust was being caused
by strong northwest winds of 40 to 60 mph.
HAZARD...Less than a quarter mile visibility.
IMPACT...Dangerous life-threatening travel.
* highway 287 and US 50 will be impacted by this blowing dust.
Locations impacted include...
Lamar, Springfield, Las Animas, Holly, Eads, Walsh, Granada, Wiley,
Pritchett, Vilas, Campo, Sheridan Lake, Hartman, Haswell, Two Buttes,
Neeoshe Reservoir, Chivington, Blue Lake, Bristol and Sweetwater
Dust storms lead to dangerous driving conditions with visibility
reduced to near zero. If driving, avoid dust storms if possible. If
caught in one, pull off the road, turn off your lights and keep your
foot off the brake.