Vince_Condella's Blog

Choo-choo, this guy is coming through whether we want him here or not.  It is the coldest air of the season and it has been trapped up in Alaska and the Yukon Territory for the past week.  Unfortunately it has it's eyes set on us for next week beginning Monday night.

Temperatures of -50 to -65 have been occurring in eastern Alaska and the Yukon.  All of the long range computer forecast models have been indicating a fundamental shift in the upper air pattern, allowing that cold arctic air to plunge southward into the lower 48 United States.  Fifty below zero for us?  No, not nearly that bad.  Those cold temperatures will modify by the time they get here.  But it could still be a nasty stretch of weather with sub-zero wind chills and daytime temperatures.

The forecasters at the National Weather Service in Milwaukee-Sullivan point out that the atmospheric parameters for next week are similar to the set-up we had around here 15 years ago.  Some of you may remember mid-January 1994.  From Jan. 18 - 20, Milwaukee had a high/low of -12/-21, 1/-21, and 10/-8.  The -12/-21 combo on the 18th was a record cold low and record cold daytime high.  Wind chills were at 70 below zero and colder.  (Note: that was using the older wind chill scale, but that would still translate to 30 and 40 below zero wind chill with our current, more accurate wind chill formula.)

You'll be hearing more about this cold wave in later blogs as the days approach.  But just for a frame of reference, the coldest temperature on record for Milwaukee is -26 measured on January 17, 1982 as well as February 3, 1996.  Let's hope that record remains standing for a while longer!

We may look like this next week.  Brrrrr....

It was one of those surreal weather situations one year ago Wednesday (January 7).  I was sitting in the weather office over a month past knee surgery with instructions to remain on crutches for another two weeks.  That sort of limits the mobility.  So there I sat in front of our computers watching a tornado warning for Walworth and Kenosha counties.  On January 7?  Are you kidding?

For the next three hours I sat on a stool in front of the computer screen and issued warnings during wall-to-wall severe weather coverage on FOX 6.  The reports were incredible and so were the radar images.  Such power and dynamics in the atmosphere in winter.  Had we lost our calendars somewhere?

Most of you remember the Wheatland tornado and a second one that struck the north side of the city of Kenosha that afternoon.  These were the first reported tornadoes in Kenosha County since 2001.

What a year it was for severe weather.  2008 ranked as the 3rd most active for tornadoes with 38 statewide twisters.  We average 21 in a year.  The most active year was 2005 with 62 tornadoes.  Second place was 1980 with 43 twisters.

The day before the Kenosha tornadoes, January 6, 2008, we tied a record high of 52 and set a record warm low of 39.  There was dense fog and a 100+ car pile-up on I-90 east of Madison.

The day of the Kenosha tornadoes featured a record high in Milwaukee of 63 degrees, the warmest temperature on record for January.

For a terrific write-up of the 2008 tornado season, including photos and cool radar graphics of some of the tornadoes, check out the following link from the local National Weather Service office in Sullivan HERE.

Okay, maybe not Titanic-destroying icebergs.  But big chunks of ice have formed off-shore east of Wind Point as seen in a very cool satellite image from Monday, January 5, 2009 (see below).  On a clear day like we had on Monday, the polar-orbiting MODIS satellite can get a great glimpse of southeast Wisconsin.  (Thanks to our friends at the National Weather Service Milwaukee-Sullivan for featuring the photo on their web site.)

What is interesting in this photo is the lack of snowcover in Racine, Kenosha, and Walworth counties.  Even southern Milwaukee County and southeast Waukesha County don't have much white on the ground.  The melting from last week has deeply eroded the snowpack.

Another interesting feature: ice free Lake Geneva and Green Lake.  They show up very clearly in this visible satellite image.  (A visible image means the satellite uses sunlight to illuminate the Earth's surface.  An infrared image can be used to image nighttime features using heat emitted by objects such as clouds.)

Nothing makes for treacherous travel like a new layer of ice.  And as was proven this morning (Sunday, Jan. 4), it doesn't take a lot of precipitation to make a mess.  Roads, sidewalks, driveways, mailboxes, and everything else had a thin coat of ice beginning last night as light rain and drizzle fell on surfaces that were at freezing or colder.

Freezing rain is one of those red flag events of winter.  When you see it in the forecast, you know things will get slick.  It is common this time of year, especially when there is a snowcover.  That snow on the ground refrigerates the air, keeping surface temperatures from rising much above freezing.  Meanwhile, if warm air moves in above us, we can see temperatures above freezing at cloud level.  Liquid water falls from the sky and then freezes on contact with the sub-freezing surfaces at ground level.

Freezing rain can produce some interesting and often beautiful effects.  The ice-coated car mirror above and the ice-coated tree limbs below are testament to nature's beauty.

But when rainfall is moderate to heavy, and the cold air is firmly entrenched at the Earth's surface. ice can coat everything to a thickness of one inch or more.  That weight brings down trees and power lines (below).

The vertical temperature profile of the lowest 5,000 feet of the atmosphere for freezing rain is shown below.  The key is the shallow freezing layer, which may be only a few hundred feet deep.  Fortunately for us, Saturday night's freezing rain/drizzle was very light and the coating of ice very thin.  But it doesn't take much to get us slip-sliding away.

Did you make the best of that "leap-second" we got New Years Eve?  You didn't?  Well, no worries.  We'll see another one of these extra seconds over the next few years.  Why on Earth would we add an extra second of time to our 365-day calendar?  Because of the Earth, of course.

Our Earth is slowing down in it's daily rotation.  Nothing too drastic.  But frictional effects will do that to you.  So every few years we need to add an extra second to our year to account for the slowing.  The last leap-second was in 2004.  I'm not sure when the next extra second will be added, but I'll be ready.  I'm making plans.

Speaking of our Earth and it's orbit around the Sun, this Sunday (January 4) is a special day: perihelion.  It is the day when the Earth is closest to the Sun during it's annual orbit.  We will be approximately 91.4 million miles from the Sun, about 7% closer than at the farthest point in our orbit, aphelion, which occurs in early July.

I know what you're thinking: Vince must have made a typo.  How can we be at our closest approach to the Sun in the middle of winter, and at our farthest distance in the middle of summer?  The seasons are not determined by the Sun-Earth distance.  Instead, it is the tilt of the Earth on its axis that makes the difference.

This time of year our Northern Hemisphere is tilted away from the Sun, so even though we are closer to the Sun, the rays of sunlight are at a more oblique angle.  The Sun is lower in the sky at midday and we don't get as intense solar radiation like we do in summer.  And during aphelion in July, our Hemisphere is tilted toward the Sun and we receive more direct and intense solar radiation.

It is truly a paradox of nature.  So close to the Sun this time of year and yet so little warmth!

Have you noticed the national news outlets' obsession with the weather this winter?  For example, ever since NBC Universal purchased The Weather Channel, they cover every flurry of snow and each drop of rain like it was the end of the world.  That's because all of those Weather Channel reporters are on-site filing reports for the cable channel, so NBC recuits them to file live reports for the Peacock Network, too.

But other cable and network news outlets do the same.  Weather is news.  Actually it's easier to cover than hard news stories and it often produces better visuals.  Have you also noticed how the networks only get excited when the big weather systems impact the major cities of the northeast?  Blizzard in North Dakota that shuts down I-94?  No worries.  Wind chill below zero and schools closed in the Midwest?  Yawn.  But if snow is set to arrive in New York, Philadelphia, Boston, or Washington, DC, watch out for extended national coverage.  I recently saw a network reporter live in New Hampshire breathlessly reporting single digit wind chills.  I can only imagine the residents of New Hampshire rolling their eyes at this out-of-towner and going about their business by simply putting on another layer of clothes.

There has been one legitimate huge national weather story which the networks rightfully covered: the snow and cold in the Pacific Northwest.  Parts of Washington and Oregon have been paralyzed by an unusual blast of winter weather in December.  It hampered Holiday travel and truly was unusual.

As long as I'm on this rant, I also love the wording used to tell the weather story.  The national news anchor will undoubtedly say "the unpredictable weather brought surprise snow and cold" etc.  It doesn't matter if the storm had been predicted for a week in advance.  Every big storm seems to be labeled "unpredictable" and a "surprise".

Okay, I'm done venting now.  Ahhhh, that feels better.  See you next year.

Christmas memories come in all shapes and sizes, but it's probably no surprise that mine pertain to weather and weather events.  Sure I remember as a kid getting those really cool things from my parents...er, I mean, from Santa.  Somewhere around 10 or 11 years old I scored back-to-back great years of Christmas gifts with an anemometer one year and a recording barograph the next year.  Sounds nerdy, I know.

The anemometer is a device for measuring wind speed.  The older models look like three cups that catch the wind and rotate.  The device is connected by wire to a wind guage in the house.  My dad mounted it in my bedroom and I would speed countless days and nights during windy Chicago-area storms watching the gusts of wind on that guage.

The Anemometer

The recording barograph is simply a barometer that measure air pressure, but records it using a red pen and ink on a rotating drum of graph paper.  I changed the paper every week.  Each strip of paper represented the ups and downs of air pressure for a seven day period.  If that wasn't the absolute coolest thing.  I could literally watch each passing high and low-pressure system on paper.  Strong gust fronts and thunderstorm downbursts were recorded by a sharp uptick in the pen and ink.  Wild stuff.

The recording barograph (above) and the trace of weekly pressure changes (below).

But weather-wise, the first and second Christmas I was here in Milwaukee had lasting memories.  December 25, 1982 we had a record high of 61 degrees.  I remember that my wife and I were on our way to the airport to fly out on vacation, and driving by Lincoln Park on I-43 we saw people out golfing.

The next Christmas, 1983, we set a record low of -12.  Back-to-back years and back-to-back record extremes.  And you thought nature is crazy this year!

Looking out at my backyard bird feeders on a frigid mid-December day, I wonder how the little creatures survive sub-zero cold and bitter wind.  The tiny birds scrambling for bird seed seem to be gobbling up every bit of thistle, sunflower, safflower, etc.  They fluff up their feathers for a little more insulation and they slow their metabolism at night, dropping their body temperatures to 88 degrees, down from an average of 108 degrees.

The tiny black-capped chickadee is truly amazing.  It consumes mass quantities of food during the day, the equivalent of 200 sunflower seeds when temperatures drop below zero.  Two hundred sunflower seeds?!  Yikes, that's a lot of food for such a little bird.  No wonder it is a bird of constant motion, always seeking out a food source.

Black-capped Chickadee

The chickadee relies on fruit, insects and seeds for their diet.  But fruit and insects are hard to come by in winter.  The little bird's beak is well adapted to cracking nuts on coniferous trees.  Watch them around pine trees this time of year to see this behavior.  The chickadees will also feed on the fat of dead animals whose bodies have been opened by larger scavengers like crows and coyotes.  Whatever it takes to increase the calorie content.

And they are big believers in body heat.  Yes, that communal living in winter can really pay off.  The chickadees have been known to gather in large numbers in confined spaces like logs or tree cavities to stay warm.

These days the weather has been harsh for us humans, but hats off to the little critters like the black-capped chickadee for surviving nature's worst.

The Climate Prediction Center is forecasting a good chance for warmer-than-average temperatures in January and for the 3-month period January-February-March.  You can find the link HERE.  The temperature maps are below...

Better-than-even chance for above-average temperature in January 2009 (above) and for the Jan-Feb-Mar period (below).

I sure hope those forecasters are correct.  I think everybody is ready for a break from this brutal cold and snow.  Don't get me wrong.  It's wonderful to have the snowcover so we can get out and play in the winter.  And it is an important item for the state's economy.  Many businesses rely on snow in winter.  But the dangerous cold makes it difficult to get out and enjoy winter in Wisconsin.

As of this writing (Sunday evening, December 21), we are experiencing the second snowiest December on record for Milwaukee.  The top 5 are listed here:

Snowiest Decembers in Milwaukee

49.5"      2000

30.1"      2008

29.5"      2007

27.9"     1978

26.5"     1951

Here is something else to consider.  This is also the second snowiest year on record for Milwaukee.  We don't often mention it, but snowfall statistics are also kept for the calendar year.  Milwaukee has received 101.4" of snow since January 1, 2008.  The snowiest calendar year was 1886 when 110.3" was recorded.

With more snow likely Tuesday and then again Wednesday, we could come very close to exceeding that mark of 110.3".  Afterall, that is only 8.9 additional inches of snow.  And after the December we have had, what's another 9" to set a yearly record!

It's 7 p.m. Thursday evening and I'm sitting down to munch on my PB & J sandwich for dinner.  No snow yet, but a big winter storm is breathing down our necks to our southwest.  But you wouldn't know it by today's peaceful sunshine and light wind.  What a glorious day.  What a deceiving day.

This is how many snow storms begin: quietly.  The air in the lowest 10,000 feet of the atmosphere is quite dry tonight, so mid-level clouds are above us with a few lower cumulus clouds moving in off the lake.  Snow is beginning to fall from the mid-level clouds, but those flakes are evaporating before reaching the ground.

However, the more flakes that evaporate on the way down means the more moist the lower layers of the atmosphere will become.  The moisture from those disappearing flakes raises the humidity level near the ground.  Eventually, as the evening goes along, those snowflakes will venture farther and farther down toward the Earth's surface before evaporating.

After a few hours of this evaporation at low levels, the snowflakes hold together and reach us here on the ground.  They may start as just flurries but will explode overnight to a wall of snow.  We can expect moderate to heavy snow showers overnight with the possibility of thundersnow.

Don't be surprised to hear the rumble of thunder overnight or see the flash of lightning.  Thundersnow is the equivalent of a summer thunderstorm, except it's cold enough to snow and the clouds don't build up as tall as they do in summer.  Snowfall rates can be in the 2" to 3" per hour range, so snow totals add up quickly.

The strong lift is created by warm air moving quickly north and riding up and over the cold air we have near the surface.  That warm air is being transported into our area courtesy of a low-level jet stream around 4,000 feet above the ground.

As you can see, between evaporation and low-level jet streams, there is a lot going on above our heads this evening.  And that will translate into a lot falling to the ground overnight and Friday morning.

It's after 8 p.m. on a Tuesday evening and I just returned from a snow measuring mission on the weather deck.  Sounds pretty impressive, huh?  It actually means I took a ruler and measured the amount of snow that has fallen so far.  (1.8" so far here in Brown Deer, but still snowing moderately)  It's been a gentle snowfall.  Little wind and dry, fluffy flakes.  A pretty scene inside looking out, but slippery if you are out driving tonight.

This snowfall lacks the deep moisture we get from Gulf of Mexico type storm systems.  Those are the ones that tap Gulf moisture and bring us the heavy, wet snow.  Tonight's snowfall is a result of a weak upper level weather disturbance and some warmer air moving northward and riding up and over the cold air near the ground.

But we are in an active weather pattern, with the main core of jet stream winds at 30,000 feet roaring at us out of the west-southwest.  Plenty of cold air is in place from extensive snowcover all the way north into Canada.  Check out this web site from the National Ice Center....click HERE.  This shows you the extent of snow and ice pack throughout the Northern Hemisphere.  We have no shortage of ice and snowpack to our north, insuring a source of cold, arctic air.

Extent of snowcover in North America according to the National Ice Center.  That extensive snowpack will keep us in the deep freeze through next weekend and beyond.

Meanwhile, the upper air winds are developing another storm in the southwest U.S. that is targeting the southern Great Lakes by Thursday night and Friday.  As always, the exact track of the low-pressure center is crucial.

We look at several computer models to guide us along in our extended forecast.  Right now the European (ECMWF) and the Canadian Model seem to be doing the best job of handling the extent or arctic air.  They keep the surface low-pressure farther south than the GFS model, which often has trouble handling shallow arctic air masses.

All of these numerical computer models are based on mathematical equations that simulate the flow of the atmosphere.  Each model has its assumptions and limitations.  The consensus, however, shows heavy, wet snowfall for Thursday night and Friday morning as this next storm taps Gulf of Mexico moisture.  Ugh!  That means a long day and night in the weather office.

And there is no rest for the weary.  It appears another surface low-pressure system may pass just south of us for Saturday night and Sunday with potential for more heavy snow.  Let's hope that one decides to take a left turn before it gets here!

Pardon me while I go on my annual rant about the term "feels like" temperature.  There is no such thing except in the mind of the media.  It's the quick and inaccurate way to describe the wind chill temperature.

Wind chill temperature describes how quickly a human body will cool if not protected properly from cold air and high wind.  The lower the wind chill means the more rapidly our body will chill.  Skin can freeze in a matter of minutes when wind chill dips below zero.  In fact, a wind chill of 0 or colder is the red flag.  When you hear that number, take extra care to dress appropriately.  That means hat, gloves (mittens are better because they keep the fingers together and warmer), warm coat, etc.

However, a wind chill of -20 does not mean it "feels like" -20 outside.  What does -20 feel like?  How is it different than -30?  You and I sense cold differently.  In fact, every human senses cold differently because physiologically we are all different.  But over the years the people in the media find it convenient to describe wind chill as the "feels like" temperature.  And while everybody else will say it, I never have and I won't start now.  It isn't accurate.

I know, I know...I'm being too much of a purist here.  People understand "feels like" much more than "the cooling power of the wind and air temperature on unprotected skin".  Whatever.  Just remember that when wind chill is 0 or colder, take extra care to dress properly.  Otherwise frostbite is a distinct possibility.  No matter what you call the other stuff.

Not to get all weather geeky on you, but that snow-to-rain and then back to snow thing we had Monday evening (December 8) was some pretty cool meteorology.  I didn't see it coming, but in hindsight it was something I should have picked up and included in the forecast.

Here's the deal:  we had plenty of warm air moving in from the south Monday evening ahead of an approaching surface low-pressure system.  Warm air is less dense and rides up and over the top of cold air near the surface.  This allowed us to get sleet and snow on Monday afternoon as predicted, along with a few spots of freezing rain.   No surprises so far.

However, I expected the warm air to filter down through the boundary layer (approximately the lowest 3,000 feet of the atmosphere) and change any mixture over to all rain south of I-94 Monday night.  Instead the snow intensified and big, fat flakes began to fall.  The wind was nearly calm so the snowfall was vertical - straight down and gorgeous.  But why the snow when warm air was clearly taking over?

At mid-levels (approx. 7,000 to 10,000 feet above the ground), an upper low center (basically a wave in the wind flow) was marching northeast out of northeast Missouri.  This created lift.  Way up high at the jet stream level (30,000 feet and higher), a strong jet stream was creating plenty of lift.  When air parcels are lifted into higher levels of the atmosphere, the air pressure is lower.  This causes the air parcels to expand and cool.  The additional cooling from this rapid lift helps change the rain back to snow.

The lift is called "dynamic cooling" meaning that the cooling was created by lift in the atmosphere rather than by colder air moving in from somewhere else.  Pretty cool and fairly geeky.  But a classic meteorological event that often occurs in winter.  As a forecaster I have to keep an eye out for this extra atmospheric "lift" to sneak into our area.

Did you get all of that?  Good.  There will be a quiz tomorrow. :)

It's all about the color when it comes to our radar maps, and tonight and tomorrow (Monday evening and Tuesday, December 8 & 9) we are seeing all of the colors.  This messy mix of weather has made for some interesting forecasting, perhaps the most challenging type of forecast I have to assemble.  Some parts of our viewing area receive snow, others rain, and still others a mix of freezing rain and sleet.

The colors on the radar depict each of those areas.  Snow is the white, with the blue hue representing the heavier snowfall.  Green is rain, with heavier rainfall in yellow and red.  Then there is the pink, or salmon, colored areas that show the mixed precipitation.

My hat is off once again to our SkyVision Plus forecast model.  This is a numerical prediction model that is used to simulate the future state of the atmosphere.  Like the several forecast models that we also look at, SkyVision uses mathematical equations that obey the law of physics and fluid dynamics, treating the atmosphere as a fluid of air, not water.

The SkyVision forecast has done a superior job of delineating the rain and snow areas as well as the mixed precipitation regions.  It nailed this scenario beginning with Sunday's model output, and it has been consistent today.

Numerical models are a huge help to the forecaster.  We use them for guidance, although we can't rely too heavily on them because some of the models do a poor job of forecasting under certain conditions.  A mix between computer and human is the best way to put a forecast together.

The challenge with this storm system is figuring out how rapidly the warm air arrives from the south and which layers of the atmosphere will warm more quickly.  That determines where the snow will change to rain.

Stay tuned, and keep an eye on those multi-colored maps!

Ah yes, it's quiet time back here in the weather office.  Time to kick back and enjoy a little dinner break between newscasts.  And since this TV work is pretty glamorous, I'll share with you some crucial behind-the-scenes information.  Where am I going for dinner and what is on the menu?  Well, my office desk is the place, and a peanut butter & jelly sandwich and a bag of veggies is the main course.  Hey, no snickering.  This tastes pretty good right about now.

In case your scoring at home, here are the snowfall totals for today's (Wednesday) snow event - yes, I call it an event because I don't want to use the word "snow storm".  I save the stronger term "storm" for times when we really have a snow storm:

4.8" Stone Bank (northern Waukesha County)

3.1" Holy Hill

3.1" Sullivan (eastern Jefferson County)

3.0" Palmyra (southeast Jefferson County)

2.9" West Allis

2.8" Franksville (Racine County)

2.6" Mitchell Int'l. Airport

2.1" Brown Deer (FOX 6 Studio)

The good news about this weather system is it behaved like we thought it would: the timing was as expected, but the 3" to 5" totals I was forecasting were more like 2" to 3" for most areas.  There was not quite as much lift in the atmosphere in the critical layer in the lower atmosphere where snow growth is most efficient.  This is the dendritic snow growth region where the temperature in the cloud is between approximately 5 and 12 degrees Fahrenheit.

We are on a consistent weather pattern right into next week, with Alberta Clipper surface low-pressure systems riding down the upper air wind from northwest to southeast.  The weak storms develop in the Alberta province of Canada and race southeast, bringing us light, dry fluffy snowfall of a few inches of snowfall at a time.

Our next chance for flakes comes on Saturday and then again Monday into Tuesday.  But enough talk of weather.  It's back to my sandwich.  And, of course, I saved the best for last....chocolate chip cookies.  (They help offset the veggies!)