Gales of November? Not so much

Posted at 4:49 PM on November 20, 2009 by Paul Huttner (0 Comments)

Twin Cities NWS wind forecast shows another tranquil November afternoon.

One of the interesting and perhaps overlooked features of our unseasonably mild November is the wind. Or should I say the lack thereof.

November is typically the 4th windiest month of the year in Minnesota, and most of the Midwest. In the Twin Cities, our average monthly wind speed in November is 10.9 mph. Only the springtime months of March, April and May have higher average wind speeds.

This November our average monthly wind speed is a mere 6.7 mph. That's barely a breath and a full 4.2 mph below the month average so far. It's also one reason our days have felt so balmy, wind chill has just not been a factor this month.

We've also seen 54% of possible sunshine this month. The November average is just 39%. That's a huge difference and one reason why we're feeling so sunny these days.

Temperatures continue to run about 9 degrees above average for November in the Twin Cities. Enjoy the blissfully mild weekend weather. As I posted before, there are big changes on the way next week. I will try and nail down the timing and amounts of any possible snow on Monday. It's going to be a complicated forecast, and a potential meteorologist's nightmare.

PH

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Alaska -46: Winter heading for Minnesota

Posted at 4:37 PM on November 19, 2009 by Paul Huttner (0 Comments)

Forecast lows are colder than -40 in northern Alaska tonight.

You knew it wouldn't last forever.

Bitterly cold arctic air is pooling in Alaska. It was a bone chilling -46 in Bettles, Alaska early this morning. The balmy "daytime" high in Bettles was -38. Ouch.

That mind-numbing arctic air mass is gaining strength under 24 hour darkness in northern Alaska, and there are signs it may make a move on Minnesota the first week of December.

Of course it will modify some, and I don't think we'll see anything approaching -40 in Minnesota yet. But it's going to feel like winter around here very soon. Real winter. We could see our first sub-zero readings of the season in Minnesota in the next two weeks.

There's an atmospheric connection between Alaska and Minnesota. Huge dips in the jet stream called "long waves" tend to space out so that Minnesota and Alaska have the inversely related temperatures. When it's cold in Alaska it's usually warm in Minnesota, and visa-versa. We can look to Alaska before a big pattern change in winter to get and idea of what's headed our way.

Round one of our colder temperature pattern appears to be moving in next week. As I posted this morning, that could mean enough cold and moisture to make for a white Thanksgiving. It looks like the real mother lode of cold air may come calling the first week of December.

In the short run, our weather will improve dramatically as we head toward the weekend. Look for plenty of sunshine Friday and Saturday, and temperatures will make a run well into the 50s by Saturday afternoon. Clouds and rain will increase ahead of the overall pattern change on Sunday.

Get out and enjoy one last shot of mild sunny Indian Summer weather the next few days. Winter is on the way. And this time, I really mean it!

PH

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Forecast: White Thanksgiving?

Posted at 8:31 AM on November 19, 2009 by Paul Huttner (1 Comments)

Twin Cities NWS graphical forecast hinting at snow Monday evening.

The weather maps are brewing up changes for Thanksgiving week.

A developing low pressure system is looking more likely Monday in eastern Minnesota and Wisconsin. Forecast models are hinting at the developing the upper low pretty much right overhead Monday. This system could have enough cold air and moisture in place for snow late Monday into Tuesday.

NOAA GFS 500 millibar(18,000 feet) chart develops upper low Monday.

It's way too early to say for sure how much snow or exactly where it might fall. Systems this far out are just too loosely organized to pin down. In fact, forecasting snow timing, locations and amounts is difficult under the best of circumstances even 24 hours before a storm. Suffice to say the chances for (a few inches of?) snow Monday are increasing.

GFS model paints precip over the area at 6pm Monday.

The first system may be followed by another Alberta Clipper type system Wednesday. A reinforcing shot of sub-freezing cold air could arrive just in time for Thanksgiving, making it likely that any snow that does fall could stick around for a white coating on Turkey Day.

The obvious consideration here is that this could affect holiday travel in the region. Right now travel looks like it could be affected anywhere between the eastern half of Minnesota and Madison Monday into early Tuesday. The second system could affect road conditions anywhere between Fargo and Chicago Wednesday.

Stay tuned.

PH

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NWS: 1" severe hail criteria goes nationwide

Posted at 4:34 PM on November 18, 2009 by Paul Huttner (0 Comments)

Last night's Twin Cities AMS Chapter meeting featured Dr. Joe Schaefer, Director of the Storm Prediction Center (SPC). While I was unable to attend last night, my weather spies tell me he broke some news at the meeting.

You may remember last summer the NWS Central Region which includes Minnesota changed the criteria for severe hail to 1" from the previous 3/4" threshold for issuing severe thunderstorm warnings based on hail size. This move was supported by me and many other local meteorologists. It appears the change was a success. Next year, the NWS will adopt the 1" standard nationwide.

It turns out you need hail closer to 2" in diameter (golf ball size) before you really start to do serious structural damage to windows and cars. Since hailstones that size fall at nearly 100 mph, it's probably wise to stick with the 1" criteria when it comes to people outdoors. I wouldn't want to be caught out on the lake in 1" hail. This is a good move by NWS.

I'm told Joe also said SPC is very concerned and will be watchful this winter for tornado outbreaks along the Gulf Coast and in Florida. El Nino winters have a history of producing deadly winter time tornado outbreaks in the Deep South.

SPC is also talking about how to increase the alert level for killer tornadoes that occur during the overnight hours.

Delta moves NWA meteorologists to Atlanta:

Another little bird told me that Delta Airlines is completing the move of the former NWA meteorology staff to Atlanta. When complete, this marks the first time the "hometown airline" has not had a staff of trained meteorologists based in the Twin Cities in decades.

In theory this should not have an effect on the quality of weather forecasts for airline operations at MSP. However, I for one have always been a big believer in the extra "eyes on the ground" data you get from having a locally based staff of weather professionals based at MSP Airport. After all, this is one of the most challenging locations for flight operations in the world, especially in winter.

I am digging deeper into this topic.

Stay tuned.

PH

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Storm pounds Pacific Northwest

Posted at 8:56 AM on November 18, 2009 by Paul Huttner (0 Comments)

GOES IR satellite image shows potent storm heading for the Pacific Northwest coastline.

We get some pretty good storms in Minnesota, but imagine the pounding they are getting in the coastal areas of the Pacific Northwest today.

A powerful storm racing southeast from the Gulf of Alaska is crashing into the Washington and Oregon coastline. Winds gusts of 50 to as high as 80mph will slam ashore, downing trees in the process. Heavy surf is churning up along the coast, making for some excellent viewing but coming with coastal flooding. Winds along the coast will shift from easterly this morning to west and increase dramatically later today.

Numerous storm warnings are in effect including high wind warnings, winter storm warnings and even an avalanche watch in the Cascades.

Imagine trying to forecast these systems in the days before modern weather satellites allowed us to see storms from space before they reach the coast.

There is a connection between powerful Pacific Northwest storms and our weather in the Upper Midwest. Pacific storms act as huge atmospheric vacuums, sucking up milder air in the central states. This usually produces a southerly wind flow and milder than average temperatures here in Minnesota. This pattern will hold true again this time with temperatures running about 5 to 10 degrees above average through this weekend.

A piece of the Pacific storm will break off and gather in the southern states by the weekend. It may then come north, and has the potential to produce snowfall somewhere between the Twin Cities and Chicago by early next week. This could affect travel plans between the Cities and Chicago if it develops.

Stay tuned.

PH

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Mild November: Open water in December?

Posted at 4:07 PM on November 17, 2009 by Paul Huttner (6 Comments)

Ice free shoreline soaking up November sun on St. Louis Bay in Lake Minnetonka. (Photos by Paul Huttner)

Things are beginning to look a little odd in Minnesota these days.

This is the week when we would expect to see snow cover blanketing the ground in the Twin Cities. Our average date for the first inch of snow cover is November 21st. That's Saturday folks. No sign that will happen this year. In fact we could be pushing 50 again this weekend.

While springtime "ice-out" data is abundant in Minnesota, ice "freeze-up" data is sparse and hard to come by for Minnesota lakes. Maybe we're all a bit in denial when our favorite lake freezes over.

Still I can remember many years when I was skating (foolishly perhaps) on smaller bays in Lake Minnetonka by Thanksgiving weekend. I would say it is quite common to start seeing the first ice forming on ponds and small lakes and bays by this week. And I've seen many years with Lake Minnetonka covered with ice by the first week of December.

Late season boater out for a mid-November ride on Lake Minnetonka.

So far this year there is not a hint of ice on any area lakes or ponds. In fact, I believe all lakes in Minnesota are ice free as of today. And if you look at the GOES 1km visible satellite image below you can see it appears that lakes are ice free well north into Ontario.

College of DuPage visible satellite image form today shows lakes in northern Minnesota and southern Ontario largely ice-free on November 17th.

The medium-range forecast maps do show a cooling trend in the next two weeks. This should bring down enough cold air to freeze up some ponds and small bays by around the first of December. Still, there are indications of periodic warm spells. That might keep the big water open for several weeks to come. That would mean open water is possible on large Minnesota lakes well into December. There is evidence that supports a climate shift induced trend toward later ice-in and earlier ice-out sates in Minnesota.

It's said there really is no bad weather, just different kinds of good weather. Most of us are enjoying our balmy November. The ice fishing crowd? Not so much.

PH

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Early November Warmth: A new trend?

Posted at 8:29 AM on November 17, 2009 by Paul Huttner (2 Comments)

Twin Cities NWS forecasts a high of 50 in the Twin Cities Saturday. The average high is 36 degrees.

The ranking are in for our unseasonably mild first half of November in the Twin Cities.

According to the Minnesota State Climatology Office, our average temperature of 45.5 degrees was the 7th mildest start to November on record. The warmth was widespread this month. Several area cities recorded top ten warm first 15 days of November including:

-Fargo: 4th warmest
-St. Cloud, Rochester & Sioux Falls: 5th warmest
-International Falls: 6th warmest
-Duluth: 7th warmest

In addition to one of the warmest such periods on record for early November, it appears a trend may be emerging in the last decade toward warm spells in early November. Four of the top 10 warmest early November periods have occurred in the past 11 years including:

#1) 51.1 degrees in 2001
#4) 45.9 degrees in 1999
#7) 45.5 degrees in 2009
#9) 44.9 degrees in 2005

The average temperature for the first half of November in the Twin Cities is 36.5 degrees.

Thanksgiving Preview: Colder

It appears our blissfully mild weather will linger though the weekend. The upper air pattern shows signs of cahnging as we move onto next week. Right now the GFS model is indicating a fairly cold shot of air by Thanksgiving Day.

NOAA GFS forecast model surface chart for noon Thanksgiving Day indicates cold air pouring southward from Canada.

This could mean highs in the upper 20s or lower 30s by Thanksgiving Day. There are some signs temperatures could moderate a bit by Saturday and Sunday of Thanksgiving weekend.

This pattern change could be a longer term trend for the rest of November as temperatures return to near or colder than average levels by the end of November.

PH

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Sky show: Leonids peak tonight

Posted at 3:56 PM on November 16, 2009 by Paul Huttner (1 Comments)

Sky map shows pre dawn sky near Leonid peak.
(Credit: NASA & Spaceweather.com)

It's a good night for clear skies in Minnesota.

Our clear crisp November sky will provide a perfect viewing opportunity for the annual Leonid meteor shower tonight. The Leonids are usually one of our best meteor showers of the year. Chilly high pressure with temperatures around freezing will make for a chilly but good opportunity to see the "shooting stars" overnight.

Meteor rates are forecast to be between 20 and 30 per hour over most of North America. It looks like the peak rates could come in Asia, where as many as 200 to 300 meteors per hour could dazzle sky watchers.

Leonids occur each year in November when the earth passes through debris from Comet Tempel-Tuttle. Every 33 years the comet visits the inner solar system and leaves a stream of dusty debris in its wake. Whenever we hit one, meteors appear to fly out of the constellation Leo.

The new moon this year will make for excellent dark sky viewing conditions. You may see meteors any time tonight, but the peak hour for viewing in the Midwest should center on 3am.

Enjoy the show!

PH

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Forecast: Frosty start, fine finish

Posted at 8:39 AM on November 16, 2009 by Paul Huttner (0 Comments)

Heavy frost greets commuters on I-94 near Highway 101 Monday morning.

Welcome back to reality.

Our frosty morning low of 26 degrees in the Twin Cities is only two degrees warmer than average. It also ties the coldest temperature recorded this fall at Twin Cities Airport. The outlying suburbs were significantly colder. It was a chilly 19 in Cambridge and Faribault this morning.

Sprawling high pressure is centered over Minnesota today. This will provide another day of bright (and rare) November sunshine and light winds. Our dry air mass heats and cools easily. All day sunshine should help us make a run at 50 today in the metro. The high will hold strong through Tuesday, making for frosty nights and sunny milder days. Temperatures will run about 10 to 12 degrees above average with highs near 50. Our average high this week is 38 degrees.

Twin Cities NWS graphical forecast temps today.

Midwest Snow:

A small but potent snow storm is winding up south of Minnesota today. Heavy snow is falling in north central Kansas and southeast Nebraska. Three to more than 6 inches will fall in the area.

Kansas City NWS weather story highlights heavy snow areas today.

Denver is digging out from 10" to over a foot of snow today from the same storm. High pressure anchored over the Upper Midwest should keep the system south of Minnesota until Wednesday. We could see a few scattered rain or snow showers later Wednesday or Thursday as the system grazes our region.

USA: Warm November

The first half of November is in the books, and we've seen near record warmth in the Twin Cities. So far we are running 9 degrees above average in the Twin Cities for November. Those numbers will drop a bit as colder air moves in the next two weeks.

The warm weather has dominated much of central the U.S. this month. It's been close to average on the West Coast, and just slightly above average on the East Coast. Here are some numbers.

November average temperatures:

-Seattle & Los Angeles: -0.6 degrees
-Tucson, AZ: +8.3 degrees
-Dallas: +6.2 degrees
-Kansas City: +9.9 degrees
-Twin Cities: +9.0 degrees
-Chicago: +5.5 degrees
-Atlanta: +0.8 degrees
-Cleveland: +3.5 degrees
-Washington, D.C. +1.8 degrees
-New York City: +1.7 degrees
-Boston: +1.9 degrees

Venezuela: Latest weather modification attempts:

We've talked about recent weather modification attempts in Beijing and Moscow. Now they're trying to ease drought by seeding the clouds in Venezuela. Reuters has the story.

Enjoy the sun today!

PH

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Sunspot show ahead

Posted at 3:40 PM on November 13, 2009 by Paul Huttner (0 Comments)

NASA Solar and Heliospheric Observatory (SOHO) animation shows sunspot 1029 reemerging toward the earthward side of the sun.

This could be a good weekend for sun watchers.

The strongest sunspot this year is making a cameo. Active sunspot 1029 has traversed the far side of the sun and is ready to face the earth again. 1029 spent the last two weeks rounding the far side of the sun. Solar astronomers will have a great viewing opportunity this weekend for profile views as the large sunspot rotates around the side of the sun.

NASA'a SOHO platform will have great views of 1029 as it makes another pass across the earthward face of the sun in the next week or so. 1029 is believed to be the first significant sunspot of what could be a ramped up solar cycle 24 in the coming years. Increased aurora activity is possible in the next 10 days as 1029 faces earth.

Weather maps in transition:

It's interesting to watch the forecast models these days. The models are having a duzy of a time resolving a cut-off low pressure system early next week in the central plains. The latest GFS cuts the low off and has it spinning over Kansas and Oklahoma Monday and Tuesday. That would allow high pressure to dominate the Upper Midwest and give us another shot of sunny skies Sunday throughTuesday.

NOAA GFS surface prog for Tuesday shows high pressure and sunny skies in control.

The same model then kicks the system north into Minnesota for a chance of rain and or snow late Wednesday and early Thursday before brushing eastern Minnesota and Wisconsin with another system Friday.

In the short run, clouds and spotty mixed precip will hang around Saturday in Minnesota. Sunday looks sunny and cooler with highs in the 40s and low 50s.

PH

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