Updraft: March 8, 2011 Archive

Snow moves in: Spring pattern & 50s next week?

Posted at 11:22 PM on March 8, 2011 by Paul Huttner
Filed under: Winter storms, Winter/spring 2011

Update 11:30pm:

Snowfall has reached the southern metro as of 11pm Tuesday night. Many sites in southern Minnesota are reporting snow as the system moves closer.

LAKEVILLE LGT SNOW 30 27 86 E9 30.12F WCI 22

Southwest Minnesota

CITY SKY/WX TMP DP RH WIND PRES REMARKS
PIPESTONE MIX PCPN 28 28 100 E6 30.06S WCI 22
WINDOM LGT SNOW 30 30 100 NE8 30.07S WCI 23
JACKSON LGT SNOW 32 30 93 NE13 30.07S VSB 1 WCI 22
TRACY LGT SNOW 22 20 92 NW7 30.10S WCI 14
SLAYTON LGT SNOW 28 27 95 NE5 30.08F VSB 3/4 WCI 23

South Central Minnesota

CITY SKY/WX TMP DP RH WIND PRES REMARKS
NEW ULM LGT SNOW 32 28 86 E3 30.11S
ST JAMES LGT SNOW 32 28 86 NE8 30.09S WCI 25
FARIBAULT LGT SNOW 30 28 93 NE8 30.11S WCI 23
OWATONNA LGT SNOW 30 28 93 E12 30.08F WCI 21
ALBERT LEA LGT SNOW 32 32 100 NE9 30.02F WCI 24

Southeast Minnesota

CITY SKY/WX TMP DP RH WIND PRES REMARKS
ROCHESTER LGT SNOW 32 30 92 NE14 30.08F FOG WCI 22
RED WING LGT SNOW 34 28 80 E9 30.13F WCI 26
STANTON LGT SNOW 33 29 86 NE9 30.10F WCI 25
DODGE CENTER LGT SNOW 32 30 93 E13 30.07F WCI 22
WINONA LGT SNOW 34 32 93 CALM 30.13F
AUSTIN LGT SNOW 32 30 93 NE13G18 30.04F WCI 22
PRESTON LGT SNOW 33 32 95 E9 30.07F WCI 26

Radar continues to show the northern edge of the snow working slowly north. The big question is how far north will the snow reach? It looks like the northern edge will be in or near the metro area early Wednesday morning, with snow at least a factor for the morning commute.

-Latest Twin Cities radar loop

The evening model runs support my thinking that there will be a big "snowfall gradient" across the metro from NW to SE. The GFS (700 millibar low center track) seems to support keeping snowfall going in most of the metro through midday Wednesday.

Snowfall potential:

It also looks like snow will last much longer in the SE metro communities of Lakeville and Hastings than in the northwest metro. (Elk River, Anoka)

At this point I still see a forecast of 1" (NW) to 4" (SE) for the metro as a good overall range. Not a blockbuster storm by any means, but it should be enough to create some slick spots and gum up AM rush Wednesday.

Heavy snow band: 4" to 6"+ (with isolated 8" totals)

This includes Mason City, Austin, Albert Lea, Rochester, Winona, Red Wing, Decorah, La Crosse, Tomah, and Eau Claire.

Plan on heavier snowfall rates and slick travel along I-35 south, Highways 52 & 61 southeast, and I-94 into Wisconsin.

Next update on Morning Edition with Cathy Wurzer at about 7:45am.

Nighty night!

PH

Update 8:15pm:

Snow is busting out in southern Minnesota and moving north toward the metro.

Here are some Minnesota locations reporting snow & mixed precip at 8pm:

Southwest Minnesota

CANBY LGT SNOW 20 19 93 NW6 30.15S WCI 13
PIPESTONE MIX PCPN 28 27 93 E8 30.07F WCI 20
WINDOM LGT SNOW 30 30 100 NE8 30.09S WCI 23
JACKSON LGT SNOW 32 30 93 NE10 30.08F VSB 1 WCI 24
SLAYTON LGT SNOW 30 28 93 NE8 30.10F WCI 22

South Central Minnesota

CITY SKY/WX TMP DP RH WIND PRES REMARKS

ST JAMES LGT SNOW 32 28 86 NE3 30.11F
OWATONNA FLURRIES 32 28 86 NE10 30.10F WCI 24
WASECA CLOUDY 32 28 86 NE12 30.12F WCI 23
ALBERT LEA LGT SNOW 32 32 100 E9 30.05S WCI 24

Southeast Minnesota

CITY SKY/WX TMP DP RH WIND PRES REMARKS

ROCHESTER LGT SNOW 34 28 80 NE12 30.10F FOG WCI 25
DODGE CENTER LGT SNOW 34 30 86 E13 30.10S WCI 25
AUSTIN LGT SNOW 32 30 93 E12 30.07S WCI 23
PRESTON LGT SNOW 33 32 94 E9 30.09S WCI 26

Radar is lighting up with snow in southern Minnesota.

Leading edge of snow moving north Tuesday evening.

Expect snowfall to move north along I-35 and reach the south metro by around 10pm.

PH

****Original post 3:48pm*****

Our (too?) long advertised Wednesday snowmaker is hanging by a thread.

The low pressure system is dropping rain and snow on much of the Midwest will steer northeast overnight. The system's southerly track will mean a glancing blow for most of Minnesota, and there are some late indications that the metro will be right on the edge of accumulating snow.

There is also still a low but growing chance that the system will veer further south, and miss parts of the (especially northwest) metro.

Here is the latest thinking on the system from the world headquarters of the MPR Huttner Weather Lab:

Track:

The bevy of forecast models is still maintaining a more southerly route with the surface low. The cluster of tracks position the surface low near Quincy, IL by 6am Wednesday, then move it through Chicago's south side into lower Lake Michigan by Wednesday evening at 6pm.

*This track is usually too far south for heavy snow in the metro, and I still expect the "heavy" snow band (such as it is) to lay across northeast Iowa, southeast Minnesota and central Wisconsin.

*There are some hints that the track could shift even further south. With the Twin Cities already forecast to be on the northern edge of accumulating snowfall, any further southward shift could mean that snowfall misses parts of the (N & W?) Twin Cities to the south!

Timing & duration:

A solid batch of moisture is surging north through Iowa. It's warm enough for rain in Des Moines (41 degrees). As the moisture hits the colder air and darkness falls I expect the rain to change to snow as it surges north into in southern Minnesota tonight.

Rain surges north in Iowa.

Expect snow to pick up in southern Minnesota (could mix at times with rain early) tonight and spread north toward the metro after midnight.

Snow should peak Wednesday morning, but could end quickly form west to east in the metro Tuesday afternoon. The duration of the snowfall could be under 12 hours in the Twin Cities, with longer duration snowfall lingering into Wednesday evening in southeast Minnesota and Wisconsin.

Snowfall totals:

If the storm stays on track, (an increasingly bigger if at this point) I still expect the following snowfall totals:

Heavy snow band: 4" to 6"+ (with isolated 8" totals)

This includes Mason City, Austin, Albert Lea, Rochester, Winona, Red Wing, Decorah, La Crosse, Tomah, and Eau Claire.

Mankato-Twin Cities-Rice Lake & Duluth: 1" to 4"

Right now I am leaning toward the lower end of that range for much of the metro pending tonight's late model run.

Willmar-St. Cloud-Brainerd: Little or no accumulation.
Expect relatively good travel along I-94 between the Twin Cities and Fargo.

System "weakening?"

The relative lack of cold air behind the system may cause some overall weakening. Also thunderstorms on the system's southern ends are sopping up moisture that would be potentially available for snow on the system's northern edge.

Bottom line: Expect snow to increase late tonight and Wednesday morning in southern Minnesota. This does not look like a major storm for the metro, and if the track shifts further south snowfall could miss some areas of the (NW?) Twin Cities.

Stay tuned...

Spring-like pattern change ahead?

Briefly, I'm starting to see a major pattern change in the jet stream over the next two weeks. The big "boss man" Hudson Bay Polar Vortex that has controlled our weather this winter shows definite signs of weakening and shifting north.

This should open the door to milder Pacific air masses in the next two weeks. More details to come, but I expect more frequent days in the 40s (starting Friday?) and it looks like we may see a major warm up (possibly 50s!) the weekend of March 19-20th.

50s the weekend of March 10th & 20th?

It also looks like we may see some rain systems zipping through, and we may not add copious amounts of snow over the next two weeks.

More on this later...stay tuned.

PH