Bill Schintler
EF4
A winter storm will bring a mix of winter precipitation to the upper-Midwest from Saturday through early Sunday. In northern MN snowfall in excess of one foot is forecast, with lesser amounts falling in central and southern MN. In IA, most of the precipitation will fall as drizzle, light rain, and freezing rain with 0.10 inches or less of ice in most locations before a change to light snow or flurries early Sunday morning. In central and eastern IA, snowfall totals will be less then 0.5 inches.
Twin Cities, MN:
Snow will start at 1:40 PM Saturday, and accumulate to 4.8 inches.
St. Cloud, MN:
Snow will start at noon Saturday, and accumulate to 5.8 inches.
Duluth, MN:
Snow will start at 7:40 AM Saturday, and accumulate to 10.1 inches.
Cedar Rapids (Eastern IA Airport), IA:
Light freezing rain or drizzle will start at noon Saturday. Freezing rain will change to snow at 5 AM Sunday with less then 0.1 inches of ice accumulation. Snow accumulation: a dusting.
North Linn Co. (Paris and Coggon), IA:
Light freezing rain or drizzle will start at 12:30 PM Saturday. Freezing rain will change to snow at 5 AM Sunday with less then 0.1 inches of ice accumulation. Snow accumulation: 0.5 inches.
Iowa City, IA:
Light rain, drizzle, and freezing rain will start at 11:30 AM Saturday. Freezing rain will change to snow at 6 AM Sunday with little or no ice accumulation. Snow accumulation: a dusting.
Marengo, IA:
Light rain, drizzle, and freezing rain will start at 11:20 AM Saturday. Freezing rain will change to snow at 5 AM Sunday with little or no ice accumulation. Snow accumulation: a dusting.
Union, IA:
Light freezing rain will start at 10:30 AM Saturday. Freezing rain will change to snow at 3 AM Sunday with 0.10 inches of ice accumulation. Snow accumulation: 0.5 inches.
Discussion:
On Saturday, an H85 low will track through IA and then into WI with an inverted trough extending N into CAN. Isentropic upglide develops after 06Z Saturday over NRN MN. STG WAA over the entire area follows, with ZR soundings FCST over IA and SRN MN for much of the event duration. A modified arctic AMS will follow in the storm’s wake, with H85 temperatures AOB -15C surging into NRN MN. Strongest forcing will exist over NRN MN beneath the left-exit region of a 100kt H3 streak.
The GFS is more progressive with the timing of the storm. The model-to-model trend has been to weaken the Manitoba low at the top of the trough while strengthening the IA low, which pushes the axis of maximum QPF and colder temperatures aloft further S while increasing snowfall potential for St. Cloud and the Twin Cities. Further S in SCNTRL MN, saturation does not reach the dendritic growth zone until Saturday evening, with temperatures of -8C to -10C noted in the H7-H55 layer so snow to liquid ratios will be relatively low there. Snow to liquid ratios will be close to 15:1 in the Duluth area, and will be range from 8:1 to 14:1 in CNTRL MN during the period of maximum QPF. In the Duluth area, any lake effect enhancement should stay just N of the area.
- bill
1:00 PM CST, 010209
Twin Cities, MN:
Snow will start at 1:40 PM Saturday, and accumulate to 4.8 inches.
St. Cloud, MN:
Snow will start at noon Saturday, and accumulate to 5.8 inches.
Duluth, MN:
Snow will start at 7:40 AM Saturday, and accumulate to 10.1 inches.
Cedar Rapids (Eastern IA Airport), IA:
Light freezing rain or drizzle will start at noon Saturday. Freezing rain will change to snow at 5 AM Sunday with less then 0.1 inches of ice accumulation. Snow accumulation: a dusting.
North Linn Co. (Paris and Coggon), IA:
Light freezing rain or drizzle will start at 12:30 PM Saturday. Freezing rain will change to snow at 5 AM Sunday with less then 0.1 inches of ice accumulation. Snow accumulation: 0.5 inches.
Iowa City, IA:
Light rain, drizzle, and freezing rain will start at 11:30 AM Saturday. Freezing rain will change to snow at 6 AM Sunday with little or no ice accumulation. Snow accumulation: a dusting.
Marengo, IA:
Light rain, drizzle, and freezing rain will start at 11:20 AM Saturday. Freezing rain will change to snow at 5 AM Sunday with little or no ice accumulation. Snow accumulation: a dusting.
Union, IA:
Light freezing rain will start at 10:30 AM Saturday. Freezing rain will change to snow at 3 AM Sunday with 0.10 inches of ice accumulation. Snow accumulation: 0.5 inches.
Discussion:
On Saturday, an H85 low will track through IA and then into WI with an inverted trough extending N into CAN. Isentropic upglide develops after 06Z Saturday over NRN MN. STG WAA over the entire area follows, with ZR soundings FCST over IA and SRN MN for much of the event duration. A modified arctic AMS will follow in the storm’s wake, with H85 temperatures AOB -15C surging into NRN MN. Strongest forcing will exist over NRN MN beneath the left-exit region of a 100kt H3 streak.
The GFS is more progressive with the timing of the storm. The model-to-model trend has been to weaken the Manitoba low at the top of the trough while strengthening the IA low, which pushes the axis of maximum QPF and colder temperatures aloft further S while increasing snowfall potential for St. Cloud and the Twin Cities. Further S in SCNTRL MN, saturation does not reach the dendritic growth zone until Saturday evening, with temperatures of -8C to -10C noted in the H7-H55 layer so snow to liquid ratios will be relatively low there. Snow to liquid ratios will be close to 15:1 in the Duluth area, and will be range from 8:1 to 14:1 in CNTRL MN during the period of maximum QPF. In the Duluth area, any lake effect enhancement should stay just N of the area.
- bill
1:00 PM CST, 010209
