Storms along east, west coasts today; our turn tomorrow

The most recent pesky nor'easter, the fourth one this month, is continuing from Long Island to Boston and up to Maine early this morning. Heavy, wet snow has been piling up. Travel has been very difficult and hazardous. Boston schools are closed for the second day.

The good news for those folks is that the snow will taper from west to east today.

West Coast

While nor'easters are tightly-wound extratropical cyclones, often with powerful winds, West Coast storms are a different beast. They usually occur when strong surges of moisture off the Pacific Ocean flow upslope to the Sierra Nevada Mountains of California or the Cascades farther north in Oregon and Washington.

The upslope flow causes condensation and the release of repeated copious precipitation.

A series of these storms has begun and will cause heavy rain, flash flooding, mudslides and heavy mountain snows in California well into the weekend. Some of the highway passes across the Sierras are expecting 3 to 4 feet of snow by the end of today and then another 1 to 2 feet from Friday through Sunday.

Severe thunderstorms are possible around the Fresno, Calif., area today.

Quiet Thursday

Not much weather will be occurring around here today. Expect thinning clouds in areas that start the day with an overcast. High temperatures should range from the upper 30s to the upper 40s in sunny southwestern Minnesota. The Twin Cities will have a high around 44 with a light east wind.

Equinoctial storm Friday

Early spring storms around the vernal equinox, sometimes referred to as equinoctial storms, can bring quite a variety of weather to Minnesota. Precipitation can be in the form of rain, freezing rain, sleet, snow or mixed precipitation.

The storm that will come our way tomorrow likely will move into the state from the west with rain in the morning. Cooling should change the rain to all snow within a few hours at any location.

Wet snow will be falling in a swath from northwest to southeast by later on Friday.

Precipitation could begin in the Twin Cities as rain later Friday afternoon or early evening and then change to all snow during the evening and continue overnight into Saturday.

Winter storm watches have been issued for a large area from North Dakota to Ohio. Winter storm warnings and winter weather advisories will be issued as the storm takes shape and forecast snowfall amounts become more predictable.

The track of the snowfall will be unusual. Instead of having an area of snow sweep across the Upper Midwest, this storm will advance eastward across Minnesota on Friday, gradually come up against some drier air Friday night and then slide slowly off to the southeast Saturday morning.

The greatest snowfalls are likely to be along and south of the Interstate 94 corridor. Snowfalls of 5 to 8 inches or more are likely across much of west central and southern Minnesota.

This pattern will create a very sharp snowfall gradient along the northern edge of the snowfall.

While the northeastern portions of the Twin Cities metro area around Circle Pines and Lino Lakes might get just an inch or two of snow, southwestern suburbs around Chaska and Jordan might end up shoveling half a foot of messy white stuff.

Farther north, from Hinckley to Duluth and the Arrowhead should remain snowfall-free.

Active weather next week

Next week might be busy for local meteorologists. A series of weather disturbances will bring periods of rain and snow to our state, beginning in northwestern Minnesota on Sunday and expanding statewide on Monday.