Issued at 4:10 PM CST, Sunday, February 22nd, 2009
Surface Analysis at 21z:
High pressure ridge averaging 1036-1040 mb was centered from Manitoba Province down through the Eastern Dakotas. Low pressure averaging 1012 mb was centered over Southwest Quebec.
Upper Air Analysis at 21z:
500 mb low had moved into Southeastern Ontario attm per water vapor satellite imagery. Northwest flow aloft continued around the Upper Midwest Today on the backside of this low. A large storm system was spinning across the Pacific Northwest/Western Canada/and adjacent areas of the Pacific Ocean Today with an upper level trough heading into the Pacific Northwest. In between the northwest flow aloft around here and the upper trough heading toward the Northwest U.S. is an H5 ridge which was building across the Central-Western Plains per 24 hour 500 mb height rises which have been pretty strong in those areas. 850 mb temperatures at 4 PM Today ranged from -18 degrees C in far Northeast Minnesota to -10 to -12 degrees C across the Southwest half of the state. -20 to -22 degree C H8 temperatures were found across Western-Central Ontario Today, but these temperatures will remain northeast of Minnesota.
Pretty quiet day around the state as arctic high pressure controls our weather. Skies were partly to mostly cloudy with highs mainly in the teens and low 20s. Winds were out of the northwest around 5 to 20 mph.
Here’s some of the higher barometer readings I could find from 3 PM Today…
Hallock Minnesota: 30.56″
Crookston Minnesota: 30.57″
Moorhead Minnesota: 30.55″
Wheaton Minnesota: 30.56″
Fergus Falls Minnesota: 30.54″
Thompson Manitoba: 30.61″
Churchill Manitoba: 30.61″
Gillam Manitoba: 30.60″
Temperatures around Minnesota at 4 PM Today ranged from 16 degrees at Lakeville to 12 degrees at Crookston to 10 degrees at Hallock to 16 degrees at Grand Rapids to 12 degrees at Ely to 13 degrees at Elbow Lake to 16 degrees at Staples to 18 degrees at Cambridge to 15 degrees at Tracy to 16 degrees at New Ulm to 21 degrees at Winona.
Arctic high pressure ridge will settle over Minnesota resulting in clear to partly cloudy skies and very cold temperatures. Lows will bottom out in the single digits, teens, and 20s below zero for most areas with northwest or variable winds under 15 mph.
Monday and Monday Night:
Arctic high pressure ridge will slide to the east of Minnesota during this period. Warm advection and a wind shift to the south-southeast will occur as this high moves away. Look for partly to mostly cloudy skies during this period with some flurries or snow showers possible across the North by Monday Night. Highs Monday will be in the teens and 20s with some 30s Southwest. Lows Monday Night will be in the single digits, teens, and 20s. Wind speeds will generally range from 10 to 20 mph Tomorrow and Tomorrow Night.
This part of the forecast is one filled with uncertainity. Basically what will see happen is a tightening baroclinic zone become established across the Northern Plains into Northern Minnesota by mid-week…This tight thermal gradient is expected to drop south/east through all of Minnesota later in the week. Low pressure systems are expected to track along and south of this temperature contrast, beginning on Tuesday and continuing into later this week. How far south this arctic air gets will determine the tracks of these low pressure systems. The models are really going back and fourth from one run to the next in regards to the track and intensity of these systems by mid to late week. Alot of the uncertainity seems to be stemming from how the polar vortex evolves this week once it reaches Saskatchewan-Manitoba. If it builds more from the Northern Plains west to the Northern Rockies, then the Upper Midwest could see a larger storm system emerge from the Plains which could cause heavier precipitation around parts of Minnesota later in the week…If the arctic air comes more directly into Minnesota after Wednesday, then any threat for a more organized storm system will pretty much be gone as the arctic air will have invaded the state keeping any storm systems on a track from the Southern Plains up toward the Ohio Valley. The forecast models will continue to struggle with how the pattern evolves in the coming days, so changes in the forecast will likely occur from day to day.
Backing up to Tuesday and Wednesday for a moment, there appears to be some threat for snow affecting the North half of Minnesota during this period, with the better chance coming sometime Tuesday Night into midday Wednesday the way it looks now. It’s certainly within the realm of possibility that a couple inches of snow could accumulate over portions of Northern Minnesota as an area of low pressure heads out of the Northern Rockies, toward Lake Superior. A potential also exists for a bit of snow, sleet, or freezing rain with this same system over parts of Western, Central, and Eastern Minnesota.
High temperatures around Minnesota will be in the 20s, 30s, and 40s Tuesday and Wednesday with single digits and teens possible in Northwest parts of the state by Wednesday. Lows Tuesday Night will be in the teens, 20s, and 30s with lows Wednesday Night in the 20s and 30s South to the single digits below to above zero Northwest.
5 Day Forecast for Duluth/Superior:
.Tonight… Mostly clear. Low 5 below to 11 below. Wind northwest around 12 mph.
.Monday… Partly cloudy. High 16 to 23. Wind variable under 10 mph, becoming southeast at 5 to 15 mph.
.Monday Night… Becoming mostly cloudy. Snow flurries possible late. Low 5 to 10. Wind southeast at 5 to 15 mph.
.Tuesday… Mostly cloudy. Light snow or flurries possible. High 25 to 30. Chance of snow 20%.
.Tuesday Night… Mostly cloudy. Light snow or flurries possible. Low 20 to 25. Chance of snow 30%.
.Wednesday… Mostly cloudy. Light snow or flurries possible. High 28 to 33. Chance of snow 30%.
.Wednesday Night… Mostly cloudy. Low 10 to 15.
.Thursday… Mostly cloudy. Snow possible. High 20 to 25. Chance of snow 20%.
4 PM Thompson Hill Observation:
Current Temperature: 18.9 degrees
Dewpoint: zero degrees
Wind: NNW at 6 mph G 13 mph
Max Temperature Today: 21 degrees
Max Humidity Today: 87%
Min Temperature Today: 1.6 degrees
Min Humidity Today: 43%
Normal High Temperature Tomorrow 27 degrees
Normal Low Temperature Tomorrow 8 degrees