Saturday’s Snow and Sunday’s Storms

*9:15 PM UPDATE…LATEST COMPUTER MODEL RUNS PUSHING LOW MUCH FARTHER SOUTH! SO FAR SOUTH WE MAY BE ON ABSOLUTE NORTHERN FRINGE OF PRECIP. COLD AIR MAY WIN THE BATTLE TO PUSH THE LOW WELL TO OUR SOUTH. STAY TUNED. WAITING ON GFS, BUT NAM AND RPM MUCH FARTHER SOUTH. ANOTHER FUN FORECAST.

MARK

Welcome to the weekend. It is going to be a busy weekend in the weather center with two different systems to worry about. The first starts tonight and lasts off and on through Saturday evening. This will be all light snow. One of the big factors generating the snow is the big temperature contrast from north to south across our area. This is known as a baroclinic zone. The official definition according to the NOAA Glossary, a “baroclinic zone” is: A region in which a temperature gradient exists on a constant pressure surface. What does that mean for our weather? It means that we will see additional lift in our area to generate light snow. This will be a long-duration light and powdery snow. Take a look at the temperatures this evening. Note the big area of unseasonably cold air just to our west.

Here is the RPM for 3pm Saturday:

The light snow will start on Friday night, then a likely break on Saturday morning, followed by more light snow on Saturday afternoon and evening. Here is the accumulation product for the RPM Saturday’s snow.

A general 1″-2″ of snow is likely. Enough to make the roads slippery, but should not cause any major problems.

The next storm arrives on Sunday night. This will be a powerful storm, but most of the computer models bring the low close to Milwaukee. That means that warm air will be brought all the way into Wisconsin. I would not be surprised if we hit 40 degrees on Sunday. My only concern is the big area of very cold temperatures just to our west. I’m nervous because an air mass like that can be tough to budge. If it holds here long enough, I would be concerned about a more southerly track and the possibility of freezing rain or sleet here. At this point, I don’t think that will be the case. It actually looks warm enough to support a few thunderstorms early Monday morning. Take a look at the RPM for 3AM Monday.

This is definitely one that you will want to watch as it gets closer. Stay tuned to Weather Watch 12 for the latest.

Mark

Advertisements

34 Responses

  1. Bring on the Thunderstorms!! Oh how I have missed thee!! I am bursting at the seams for some summertime weather!

    • Kelly,

      A little more patience. Summerfest is only four months away.

      Mark

  2. Springtime weather at anytime during winter is never a good thing. Like you said on the 10 p.m. show Thurs., Mark, if it does come as rain it’s going to be significant enough to cause flooding. Been there — done that — don’t need to go there again. Also, it’s my personal belief {hunch/opinion/gut feeling} that we’re still having frost and cold and even snow at times during spring months because we didn’t always get it when we should have during winter months. For me let’s have winter now and get it done with so we can enjoy a real spring and summer for a change! Bring on the snow!!

    Mark — I notice you said in the blog that if the cold air stays put we would still only get sleet. What has to change for us to get snow? What does a storm track need to look like for us to get snow? Thursday storm missed us too far south — Sunday missing us {snow wise} because it comes too far north. Where’s the “happy medium” line? And, any chances Sunday storm track will change? Or are the models not pushing it north and south with every run as they have done with most others?

    Thanks for “listening” and answering!

    Don

    • Hey, Don,

      We all remember how nice last spring was. I am not expecting a repeat performance. Sorry.

      The storm would have to stay pretty far south for us to be all snow. Still a lot of questions for a storm that is only two days away. Models have been pretty consistent with northerly track near Illinois border. Let’s see where they come down in tonight’s runs. Thanks.
      Mark

  3. Hey Mark, any thoughts on the system about 9 days out? I suppose it’s a little ridiculous to even ask that seeing as everything always changes. But do you know where that system would match up with the LRC?

    • Hey, Dan,

      I took a quick look. May be the 18th of January. I’ll have to do more homework.

      Mark

  4. If the low moved south, we would mostly snow, right? Or freezing rain? If so, how much snow/ ice would it be? We wouldn’t receive the .75″ of moisture possible at the moment, correct?

  5. Mark – I am not sold on the 0z NAM southern path. The cold air will certainly be a consideration and a shift closer to the edge of the new snowpack is a consideration, but while doing some convective analysis [yes a chase may be closer than I think], the 850s and associated LLJ is really kicking…I wouldn’t be surprised to see a nudge north again in more of a meridial flow. I expect this storm to continue to deepen in the upcoming models and slow a hair..this should allow a bit of ridging east of the deepening low pivoting a bit more NE. Trying not to read too much into it…but I wouldn’t give up hope of catching a bit of the cold side…

    • Scott,

      GFS still hanging around. Sleet/freezing rain possible. My other concern is t-storm outbreak just south of us robbing our moisture. Looks like there will be a very sharp edge to the northern fringe of the storm. I’ll let Luke and Jeremy have fun with this one this weekend. I certainly buy the slowdown.
      Have a good weekend.
      Mark

  6. Wow, Mark! Talk about a shift! 😀 From what I gather by the NAM and GFS, we’ve gone from almost all rain (and heavy rain) to possibly much less moisture and more snow, right? Doesn’t it look like whoever does get the snow will be in a very narrow band? Jeez, another interesting one to watch… as you say, “fun, fun fun” 🙂

    • Dan,
      Very narrow band indeed. Maybe sleet or freezing rain as opposed to snow. This is another storm that brings hair loss. I’ll be completely bald by the end of winter.

      Mark

      • LOL! I’m wondering if there will be another northern shift to bring snow to MKE. But with the band being that narrow, who knows. But doesn’t it look like there could be heavy precipitation even on the back end of the storm? Can’t wait til tomorrow’s models!

      • It’s a wait and see now. I’m getting good at punting.

      • Haha very good, very good.. enjoy your weekend!

  7. I was looking forward to 40ish and a nice half inch of rain to melt some of this white stuff. Ehh maybe it will be 40 and rain by May.

    • In due time, Bryan. Have a good weekend and enjoy watching how this one plays out.

      Mark

  8. Looks like there isn’t even going to be a snow side to this system anywhere. The 850 line is pretty much where the precip cuts off on the 12z model runs.

    • I know, it’s so disappointing!!

      • Dan K or Dan G —

        I’m confused! I thought this was supposed to be such a huge, powerful storm system headed right for us. Thursday reports were too far north for snow, so rain. Friday night too far south for snow or rain. What happend now??? Last night Mark said somethng about cold air pushing it away?? So it’s too cold for snow? I’m quite the naive novice about all this. Could one of you explain to me in simple terms what happened? Could something change so that we get a big snow yet?

        Thanks for helping me learn and understand.

        Don

      • Howdy, Don! I understand the confusion 🙂 I’ll try and explain this as best I can… it’s a tricky forecast… one of those that makes me not envy Mark and Jeremy 😀

        The image below is from yesterday afternoon’s model for Monday’s storm.

        The red lines that run from around Madison to Manitowoc is the rain/snow line. As you can see, it looked like mostly rain on the front end of the storm. The beginning (front end) of the storm usually brings the strongest precipitation. But there was a chance it would change over to a bit of light snow once the low moved further east. I think everybody was thinking that if the low pressure moved a bit further south, Milwaukee and SE Wisconsin would be much closer to the rain/snow line and possibly tap into freezing rain/sleet/snow.

        However, as of last night and this morning, the models are showing that it’s moved significantly south. A day or two ago we were talking about the possibility of an inch or so of rain, and now we’re talking about very little of anything. http://i52.tinypic.com/2h355yq.gif

        Even if it moved a bit further north, I think we would be seeing more rain than snow… and have very little if any accumulation of snow. If you look at the image I posted above, you can see that almost all of the precipitation is south of the red line, meaning that there would be a VERY narrow band of snow, if any at all. I think it’s likely that no one sees much snow out of this, no matter where you are in the midwest. I think it might be almost all rain for just about everybody. But as you know, things can change very quickly.

        Here’s one more image from this morning’s model:

        It shows that as of now, it looks like everything goes south.

        So in short: Either we get nothing, or we get just about all rain. More than an inch or two of snow seems very unlikely for us. But since I’m still an amateur myself, anyone else on this blog can correct me if I’m wrong 🙂

      • Dan,

        An easy way to see that the cold air is winning is to look at the numerical output for the NAM and GFS today. Both have temps in the mid 20s early Saturday afternoon in Milwaukee. At 2pm the actual temperatures was 19 degrees. This is a good sign that the models are not picking up the cold air very well. This means in all likelihood that the storm track will be farther south. I think on Sunday we see some light snow/flurries then a possible wintry mix. It will be a close call since it looks like we are on the edge of the storm.

        Jeremy

      • Thanks, Jeremy. I appreciate your help, as I’m still learning! So do you think a good deal of snow is possible? The NWS isn’t even saying anything about snow Sunday night.

        Dan

      • Dan,

        I don’t think much snow Sunday night. Most of the moisture stays to our south.

        Jeremy

  9. I’m with “Bryan from West Allis”
    I wanted the rain to get rid of this ugly snow.
    Now it is just more cold so that the snow sticks around even longer. Yawn. Maybe some signs of Spring by May this year.

    Do you have a count of how many consecutive days we’ve had snowpack on the ground Jeremy? I have not seen grass in the yard since December.

    • I don’t think there is a sun up there in the sky anymore either!

  10. Dan K. —

    Thanks for your answers. I have a lot of learning to do, but the journey is exciting and interesting and frustrating too — such as with this storm as when the early talk points to a big snow — then lots of rain — then a mix — then nothing. It’s like expecting you’ll get a really great gift in that big box at Christmastime only to find the box is empty when you finally open it. It’s the way these models mess with our expectations that I find the most frustrating. SIGH!!

    Among the things I still don’t understand — how can cold air push a snowstorm away from us? I would picture cold air as inviting a snowstorm not shooing it away. Anybody have any explanations?

    What are anyone’s thoughts on when to {possibly} expect another big snow?

    Thanks!

    Don

    • Don,

      How much snow have you picked up today? Keep in mind storms love moisture, and when the warmer temperatures are pushed farther south, so is the moisture source. Colder temperatures hold less moisture, warmer-more. Often times a storm track can have huge temperatures spreads on either side. Like right now it is 19 in Des Moines, but 42 in St. Louis.

      Jeremy

      • Hey, Jeremy —

        Here in Reeseville — Dodge County — we had a light dusting overnight — I could still see the cracks in the sidewalks under the “dust” — and we’ve been getting big flakes since around Noon. I would say between 1/4 to maybe 1/2″ all totaled — but the 1/2″ would really be stretching it. I was going to wait til tomorrow a.m. to measure and do any necessary clearing away of it. I think Mark’s forecast last night of 1-2″ will hold true — with the 1″ being the closest to the final number. I’ll let you know for sure tomorrow.

        Am I the bigger “flake” for setting myself up for disappointment by getting too excited too soon about snowstorms?

        Don

    • No problem! Hope it helped a bit…. 😀 I feel the same way, being bummed when we don’t get much snow. Except I’m kind of glad because I have to shovel for 4 or 5 people and when it all comes at once, it can be difficult to get it all done!

      Jeremy will have to answer your question about the cold shooing it away… I think usually storms are caused by two air masses? One cold and run warm… so in this case, I think it’s just that the precipitation is staying further south is all. Right Jeremy?

  11. It is fun following this blog, it was nice to see the sun yesterday for a while, I have a touch of SAD (seasonal affectonal disorder) and it is great to see the bright sun and blue skies, at least it looks like a couple of sunny days mid week.

  12. mark, we picked up 3 inches of dry fluffy snow in juneau so far today. still coming down moderatly. i would expect around 3.5 inches for the storm total today.

    • Steven,

      Thanks for the update!

      Jeremy

    • Steven —

      What a big difference in snow totals 12 miles away from Juneau makes. Here in Reeseville, 12 miles from Juneau, we have nothing anywhere close to 3.” Your 3-5″ will be 1″ or less here. I’ve noticed Juneau reports as always being heavier than most other Dodge County reports all winter long. Any thoughts as to why you get snow in heavier amounts than the rest of us?

      Don

      • don, i have no idea, all i do is go around the yard, taking up to 5- 8 measurements, then going with the average. its definately harder with it being windy, but today was easy. i never measure on the pavement, because most of it melted on contact. i usaully measure on grassy surfaces that have been cleared of snow. all i can think of is we get lake effect over here. LOL… J.K. !!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: