Saturday, January 31, 2009

Those Fine 40s and 50s!

So instead of talking about the inclement cooler weather on the way, I figured I'd show crazy proof that warm weather was actually here so that we can look back and remember warmer times on Monday! :) Keep in mind, high temperatures this time of year are supposed to be around28 degrees this time of year, so many places ALMOST hit double the normal high temps! A lot of melting snow today, but a lot of people got out to Great Bear for FunSki... Dave from Dakota Aerials sent us these pictures from today!





Hope you got to hop outdoors and enjoy the warm temps and melting snow!
~KDLT Meteorologist Jesse Ritka

Friday, January 30, 2009

Warm then Windy!

So I'm going to go completely scientific at this point, and explain one way meteorologists can tell when warmer weather is headed our way... This is a map of the heights, temperatures and winds currently at 850mb. The thick black lines are the lines of constant height, the thin lines with little barbs at the end are the wind barbs (each little barb represents 10kts and a half a barb is 5kts), the colors are the temperatures - the reds are the warm ones and the closer to blue... the colder the temps. One way we can tell warmer weather is on the way is when the wind barbs cross from a warmer color towards a colder color with the barb part sitting in the warmer colors. So as you can see in the circled area around SD, the wind barbs in the Western portion of the state are in the red/orange color and point towards a cooler color, in this case the tan color. Since that's going on, that means that warm air will be moving in that same direction, this is what we call "Warm Air Advection" (WAA) and in order for it to really warm things up, we see this similar pattern in several layers of the atmosphere, we usually check for WAA in the 700mb layer as well as in the 500mb layer, if all three layers have WAA present - you can definitely expect warmer weather!
Another thing you can tell by this map is there are more wind barbs on the Western half of the state and in Montana and Wyoming than there are on the Eastern half of the state, which also means that windier weather is heading towards our area for later Saturday afternoon and into Sunday.
Enjoy the "heat wave"!
~KDLT Meteorologist Jesse Ritka

Light Snow

A little bit of light snow passing through the state this morning. Visibilities generally above a mile so not real worried about a whole lot of travel difficulties. Some areas toward Central South Dakota could pick up a half inch or so. But areas toward the east are just looking for a dusting at best. The snow is associated with a warm front as Jesse mentioned and that front is pushing through central South Dakota right now. I drew a line where the front is currently located.You can see by the red numbers on this surface plot that temperatures out ahead of the front are in the single digits and temperatures behind the front are in the twenties and thirties. Expect your temperature to spike a good 10-15 degrees in an hour or two when the warm front finally passes by. Also, the accumulating snow should be done by noon with just a few flurries across the east in the afternoon.

~KDLT Meteorologist Cody Matz

Thursday, January 29, 2009

Snow then the Much Anticipated Warm Up!

A few flurries already are passing through tonight as the warm front pushes across the state... they won't accumulate to much besides over in the Black Hills area and Rapid City area.This warm front will bring a return of SW winds, increase the moisture in the air because we'll be bringing up the more humid air from the South and when that air collides with our colder dry air we're left with these flurries.This is a satellite picture showing where the snowline is... and it will be decreasing over Friday and Saturday. We'll see a very distinct line of warmer temperatures where there isn't as much snow. The area where there's more snow will still see warmer temperatures than we've been experiencing lately, so you can still expect temperatures to climb into the mid to upper 30s. Average temperatures this time of year are supposed to be near what they were today, in the mid to upper 20s, so a 10-15 degree increase will feel like a heatwave for most... be sure to take advantage of the warmer weather if you like it though, Super Bowl Sunday ushers in the colder weather once again. Enjoy the heat wave!

~KDLT Meteorologist Jesse Ritka

Wednesday, January 28, 2009

Warm-Up For This Week/Weekend

We've mentioned it a little bit off and on over the last couple of days - both on-air and off - and now it's headed our way... What is headed our way? A nice warm-up just in time for the weekend! This Saturday should make up for last Saturday's cold & windy weather.

We'll watch as a warm front makes its way through Friday, after tonight's cold front cools us for Thursday. That will give us clouds & flurries - but also highs near 30! This is where the warm front should be come about 6am Friday morning:

The warm front is the line drawn with little red semi-circles that is also red itself. Notice the forecasted little blurbs of snowy stuff - those will likely fall as some flurries around the area, not any true snow showers.

So - now that you've seen the warm front, you are probably wondering just how warm it'll get, right? Well, there is good news with that. If things end up just right, we could end up with temperatures close to 40 degrees again. Look at this computer model forecast map:


These are forecasted highs come Saturday - which should end up being our warmest day of the weekend, as we wait for a slight cooldown on Sunday.

If you look closely at the map, you'll see shades of green sneaking into the area. Those shades of green represent the potential for some 40s on the map! Some places farther to the West could end up close to or above 50 by Saturday afternoon!

Stay tuned for more updates & have a great night!

~KDLT Meteorologist Aaron Shaffer

Warmer with a dust of Snow

A much warmer look to today's temperatures as highs will be 10-20 degrees warmer then yesterday. The cause of this warmer air is because the atmosphere will be well mixed today. I explained mixing in a previous post if you don't remember what it is. Unfortunately though, because of those winds, it will probably feel about as cold as yesterday just because the wind chills will be in the single digits and teens this afternoon.The warmer air will likely be accompanied by a few snow showers over the next 36 hours as well. The models disagree on this a bit but there looks to be enough moisture to have some scattered light snow. Here is an example of a couple of different models.

Notice that these models disagree in the amount of precipitation over this time period. The light green indicates a .01" and the dark green indicates .05". The very light amounts indicated on the models typically tells us that its likely that it will be scattered about and not just one broad area of snow. So, expect a snow shower here and a flurry there but it will likely add up to very little in the long run.

~KDLT Meteorologist Cody Matz

Tuesday, January 27, 2009

Diamond Dust?

If you happened to be out and about in Sioux Falls today, you might have noticed some glittering objects in the sky. You probably thought it was snow - which was right - and probably thought that snow was just blowing around. The only problem: light winds. What was actually happening was a phenomena when snow forms without clouds. I'll go a little in depth with this, but you can always ask questions if you have any.

So... for ice to form you need something for it to form on, or it has to be REALLY cold. You can potentially have below-freezing water that stays as a liquid, and then touch it and it instantly turns to ice. This "thing" the water freezes on is called "ice condensation nuclei" and can be anything from pollutants from humans to just dust in the air. We'll pretend that this "diamond dust" was from dust and not humans for now...

So we know how ice crystals form, why didn't clouds for first? The answer to that is you need what's called an "inversion," or a region of air where temperatures *increase* with height, where you would typically notice temperatures falling as you go higher above the earth. An inversion then traps in those pollutants (the dust we mentioned above) near the surface. In this case we were chilly, in the teens, so that means the air above us would be somewhere close to that or even potentially slightly warmer. As you might know, hot air rises - so when warmer air hits air that is even warmer than itself, it stops rising. That point is where an "inversion" occurs and traps in all the air below it.

So, we had lingering humidity, trapped air, and trapped dust particles in the ideal growth temperature for snow (about 10 or so degrees Fahrenheit) - all of that equals this picture below:

Unfortunately my digital camera was not working due to dead batteries, so I found this picture from Japan above. Hopefully you saw it for yourself, and if you are interested in reading more about why this happened and why this occurrence was actually a rare instance given our temperatures, check it out in Wikipedia!

Have a great night and enjoy the slight warm-up for Wednesday!

~KDLT Meteorologist Aaron Shaffer

Huge Storm to our South

I am going to step away from South Dakota weather for one post because of some incredible events unfolding in other parts of the country. An ice and snow storm is beginning to cripple nearly a dozen states this morning from Texas and Oklahoma eastward through the Ohio valley. Ice has effectively shut down Oklahoma City and hundreds of flights in and out of several major airports have been cancelled, and this is just the beginning as the worst is still to come. By the time this storm is over, it may have effected over 25 states, grounded planes from Dallas to Boston, and left tens of thousands of people without power. Here is a current watches and warnings map for the US as I am writing this.You can see that this map looks like Easter with the smorgasbord of colors. These advisories include Ice storm warnings, winter storm warnings, freezing rain advisories, and nearly half a dozen others. I looked earlier this morning and Paducah Kentucky had already seen nearly 2 inches of freezing rain. That's incredible considering it only takes .25 inch to bring down trees and power lines.

Freezing rain forms when a warm layer above the earths surface melts the snow and turns it to rain. Then, the rain falls to the surface. But with surface temperatures below freezing, that rain will freeze on contact. Here is just one example of what freezing rain can do.
In the next day or two, this storm is going to travel through the Ohio valley and into the northeast continuing to drop copious amounts of freezing rain and sleet as well as anywhere from 2-12 inches of snow. If you are traveling by air over the next couple of days, you definitely want to call your air carrier because they are expecting thousands of delays and cancellations.
~KDLT Meteorologist Cody Matz

Monday, January 26, 2009

Strange Weather Pattern...

As we wait for high pressure to come in and clear us out (in general, high pressure induces sinking and drying area, hence the "clearing" associated with high pressure - feel free to ask any more questions about that you might have in the "Comments" section below) we are still seeing some clouds and flurry/dusting chances of snow.

Here's what we're looking at computer model-wise for early tomorrow morning:

We're having some confidence issues with the clearing for Tuesday, but this is a short-term rapid updating model that is starting to show clearing toward early Tuesday. Look closely at our area. You see all the darker colors farther toward the South. Then there are still some shaded areas that still indicate potential cloud masses, but in general we're starting to see clouds breaking apart.

Then, we get warmer! By Wednesday you might be getting upper 20s to lower 30s!

Have a great night!

~KDLT Meteorologist Aaron Shaffer

Cold Pool

Some chilly air will be sticking around for the next couple of days as we get just a cold pool of air to park itself over much of the state. Here is what I'm talking about. Look at the 850mb temperatures for this afternoon and tomorrow afternoon.Notice the circular like shape to the really cold air. It gets its name because the cold air literally pools up and makes a circular like shape. Now, once we get past tomorrow, it looks warmer. Wednesday's 850mb temperatures are warmer by over 10 degrees Celsius. You know what that means, Warmer air is on its way.

~KDLT Meteorologist Cody Matz

Sunday, January 25, 2009

Snow Tonight? Warm-Up This Week?

We have a couple of different weather things going on the next week - the first is finishing up today until tomorrow. The first being the snow. Most of it has fallen toward the South and the West. Here's a webcam view from Casper, WY (where I used to work as a meteorologist before arriving in Sioux Falls):

They're seeing heavy snow out to the West - but it's a little different here. I just got done showing our KDLT Skycam on our 5pm Sunday newscast, and we're seeing little breaks in the thin clouds, as the snow is nowhere near us for now. It is snowing in the Sioux City area, though, we also grabbed a webcam shot of there 1-2 inches they've picked up so far:

Now... we mentioned a warm-up earlier, so if you're still with us you are probably wondering about that. Look at this model-forecasted temperature map for next Saturday:

While it will not be warm as compared to your traditional vacation destinations, we'll be seeing a "heat wave" of our own with some 30s to 40s on the map. We'll hope it actually pans out - and have a great Sunday night!

~KDLT Meteorologist Aaron Shaffer

Saturday, January 24, 2009

Snow Doesn't Look Promising

The snow storm that we have been talking about for a couple of days now continues to be unimpressive, at least in South Dakota. The latest models still have the heaviest of the snow in Nebraska with just the extreme southern areas of South Dakota getting some accumulations. Here are a couple of those models.Looks like all of the accumulating snow will stay south of I-90 and only places like Yankton, Lake Andes, and Winner may get more then an inch. But it won't be much more as we are expecting most areas down there to get 1-2 inches. Looks like Sioux Falls may not get any snow although we still could get a dusting or so but that would be about it. It's also going to remain cold over the next couple of days so keep the heavy coat, gloves, and hat handy for a while. Stay warm!!

~KDLT Meteorologist Cody Matz

Friday, January 23, 2009

Cool Image... Scary Destruction

Some fellow meteorologists from the Green Bay National Weather Service office found a pretty cool satellite image that illustrates the destruction that can come out of a tornado.

Look at this image below:

You can see the track highlighted from a tornado on June 7, 2007 in northern Wisconsin.

The reason you can see it? Because it was a FOURTY MILE LONG track of damage! Quite a scar from that tornado.

Crazy stuff!

~KDLT Meteorologist Aaron Shaffer

Cold Blast Of Air Today!

You saw it with Cody this morning - blowing snow and wind. I saw it & experienced it myself. Moving to a new apartment today in the cold and wind was NOT FUN at all. Wind chill values of about -10 to -15 outside the whole 5 hours or so out there, and with probably a good 5 more hours of moving to go for this weekend - should be a great time out there! Hopefully if you are reading this you didn't have to spend very much time outside. The good news is that the winds will be calming overnight. The bad news: calming winds allow the actual air temperature to plummet. We'll get below zero tonight thanks to calming wind and clearing skies.

Old Man Winter will try to unleash some of his fury this weekend. It is still looking like most of the snow potential will be south of I-90 for the eastern portions of our viewing area - gradually increasing to be north of I-90 as you head toward western South Dakota.

Here's what we're thinking so far:

As the title of this image mentions - this was only our first take on totals. Keep that in mind if you are doing any traveling to these snowier regions. We've been seeing these snowfall totals shifting south & north quite a bit, but for about 24 hours now this is where the heaviest snow is trending, so it's looking good for now. Stay tuned this weekend!

Have a great night & bundle up! Remember those wind chills will have the potential to give you frostbite in about 10-15 minutes on your exposed skin!

~KDLT Meteorologist Aaron Shaffer

Blowing Snow in the Northeast

What a difference a day makes huh? Not all that cold outside when you just look at the actual air temperature. But when you combine the 20-40mph winds this morning, wind chills (what it feels like) are well below zero in most cases. Well, because of that wind we have seen some good blowing snow from Marshall MN over to Watertown and continuing northwest to Aberdeen. Here is a picture from a SDDOT cam looking south on I-29 around Watertown real early this morning. You can see the snow blowing across the interstate making travel a little tricky.Well, we have seen blowing snow in Watertown, but we haven't seen blowing snow in a lot of other places that have snow on the ground. The reason for this is just how warm it got yesterday. Here is a map of the actual high temperatures from yesterday.
Notice that places like Sioux Falls, Mitchell, and Huron got above the freeze mark and areas like Watertown and Aberdeen did not. Well, the areas that got above freezing yesterday had some snow melt. It may not have been much but it was likely that at least the very top layer of snow had melted. Once it melts into water, it will refreeze into ice once the temperature drops below freezing. That actually creates a little "crust" on top of the snow and will actually prevent it from being blown around. So, with the winds this morning, places that have not made it above freezing the past couple of days had some blowing snow and areas that did make it above freezing had no problems at all. Except the fact that its just dreadfully cold. Well, I hope you can get used to it because it looks like we will be in a deep freeze until sometime next week.

~KDLT Meteorologist Cody Matz

Thursday, January 22, 2009

Addressing The Snow This Weekend...

If you are reading this and live to the north of I-90, you are probably in luck, as far as snowfall totals are concerned. It looks like most of the snow will be farther toward the South and West as we head into Sunday morning/early afternoon.

Additionally, if you read last night's blog post by me, you probably saw mention of how we had an image to show you and the system wasn't working to actually let me post it. Here it is - and it shows snowfall totals computer models thought we'd see Sunday from YESTERDAY (keep that in mind, as things have changed a lot in 24 hours):


Look at all the snow the models thought we'd be getting! Now, it remains to be seen just how much we'll get and maybe we'll be looking back at this slide come Monday, but here's what the latest computer model forecast puts us at for the region:

Notice how the bulk of the snow has now shifted about 100-200 miles toward the South. If this model pans out we'd *maybe* pick up 1-2 inches of snow. It seems iffy. This system is more of a conglomeration of a few different smaller systems - so if they don't all come together just right we might only see a few scattered snow showers. If they all come together right - watch out.

Have a great night and bundle up! I'll be moving to a new apartment tomorrow in the cold & wind, so I'll know what's going on pretty well by the time I get in to work.

~KDLT Meteorologist Aaron Shaffer

January Returns

Enjoy the last day of mild air today because some big changes are waiting in the wings. Another arctic cold snap is headed in our direction with temperatures plummeting tonight through much of the day tomorrow. A look at 850 mb temperatures shows the cold air funneling into the upper Midwest. The three pictures below start at noon today, then midnight tonight, and then noon tomorrow. The temperature over Sioux Falls drops over 20 degrees Celsius in 24 hours which is just tremendous. Expect highs today in the middle afternoon and then temperatures falling for basically the next 36 hours. Temperatures will fall all day Friday, including the day light hours, and then bottom out Saturday morning with below zero readings likely in many areas. It will be staying cold through the weekend AND we have the possibility of snow Saturday night through Monday. The models are not agreeing real well yet on just where the snow will fall and how much we will get so I wont get ahead of myself, but you can expect us to address the situation in the next couple of blogs. Enjoy the mild weather.

~KDLT Meteorologist Cody Matz

Wednesday, January 21, 2009

A "Bonus" Day Of Warmth... And Snow This Sunday?

If you're like me you've definitely been enjoying this change in weather fortunes over the past couple of days. We went from bone-chilling cold last week to more moderate temperatures - but with clouds. Finally, we broke free of all of that today and got into the upper 30s and had sunny skies as well.

I went out and snapped a picture of the Big Sioux River's melting - right near our station. That's definitely a welcome sight - even knowing that a cold snap is on the way for this weekend (highs back in the single digits and low teens).

Here's the latest on the snow we're looking for this weekend:

If you read our blog post last night we were seeing two different systems mashing together and not much of a break between the two, but now things have been sorted out a bit. It looks like the bulk of the snow will fall on Sunday - and now we just have to figure out exactly where, and how much... We're having problems with the blog system as I try to upload the next image, but if I can get it sorted out you'll see that the computer models are trying to get us 4-6 inches of snow for this next storm... right now I'd say 2-4" is more likely, and we'll see if even that holds true.

Have a great night!

~KDLT Meteorologist Aaron Shaffer

Snow Cover

I know that I talked about this already once this week but I found a really cool picture that I wanted to show. This is a visible satellite image of the state of South Dakota. Basically what that means is if you were in space and looked down on South Dakota, that is exactly what it would look like.
Now, you notice that much of the eastern and northern parts of the state have a white tint. Well, thats actual snow thats covering the ground. By looking at this picture, you can see where the actual snow cover ends; I drew a line on there to help you out.

The next picture is the same satellite image but the actual high temperatures from yesterday are overlaped on top of the map along with how much above or below average they are.
You can notice that the highs almost identically coincide with the snow cover line. So basically, the more snow thats on the ground, the cooler the temperatures. Pretty Cool!! You can expect a similar temperature gradient across the state today with highs in Rapid City in the 60's and highs along and east of I-29 in the 30's. Enjoy!!!

~KDLT Meteorologist Cody Matz

Tuesday, January 20, 2009

Fun With The Warmth...

Well, you know it's a January thaw when... (insert joke/line here). You know it's a January thaw when you are getting pictures of people ice fishing - in boats! We got a couple great viewer photos sent in that really show what happens when it gets into the upper 40s to low 50s.

Looks like some fun times in Chamberlain today - hopefully they caught some good fish! Remember that you can always email us ANY photo you might have by emailing them to weather@kdlt.com or to me at a_shaffer@kdlt.com.

Now, after discussing the warmth - and there's been a lot of it - we have to discuss some more wintry types of weather for this weekend...

We briefly mentioned it last night in our blog, but there is the potential there for a few inches of snow to slide in from the Southwest Saturday to Sunday and Monday. Right now it's still not very organized, and to be quite honest it looks very odd, but we're seeing snow moving through the area for the weekend along with some thicker clouds.

Typically with a storm system we will not see snow for more than 24 hours - and the computer models are implying about a 48-60 hour snow event, so here's what we are seeing...

Saturday near noon - pretend that this is "future radar" and this is what an extended model is seeing for Saturday:


Then for Monday near noon:


What will likely happen is that this mass of snow showing up will separate itself into 2 separate events. We shall see.

Have a good night and good luck fishing if you are planning on boating in Chamberlain, haha. Just make sure you're careful for thin ice!

~KDLT Meteorologist Aaron Shaffer

Clouds Clearing

Aaron had talked alot about the clouds hanging around across the east yesterday. Well, they stuck around overnight and we are still dealing with them this morning. However, if the computer models are correct, it looks like those clouds are finally going to clear out of here today and some sunshine is in the forecast for this afternoon. Here are is a look at what the models are thinking. The pictures below are 6 hours apart starting at 6am this morning.What you see is clouds over the east early this morning but they eventually break up and filter their way southward. This particular model has the clouds almost completely out of the area by noon. I think that we will see atleast a few clouds sticking around longer then that but you get the general idea. Plenty of sunshine expected this afternoon, tomorrow, and Thursday so hopefully you enjoy it!

~KDLT Meteorologist Cody Matz

Monday, January 19, 2009

With Cody's post below about how snow cover influences temperatures... I'll move on to more warmth discussions as well as a discussion about clearing and snow potential this week. We're starting to see signs on snow this weekend.




Clearing:




We all want it - unfortunately only people in western South Dakota had it today... that'll change for the most part by midday tomorrow, but we were stuck with it today.




Here's what it looked like in Murdo this past afternoon, where they are probably wondering what the problem was with a lack of sunshine...







Then, you can contrast that with clouds toward the East in Watertown, along with some blowing snow:


You can almost *see* the temperature contrast from west to east, and that'll be hanging around for a while - but the good news is that the colder temperatures will gradually become warmer through Wednesday.

We mentioned the chance of snow, too, so here is what we are thinking about that... it's just recently started showing up on our extended computer models centered around Sunday (at least the best chance for accumulation). If you look at our 7-day forecast we show it starting on Saturday afternoon in Sioux Falls and lasting into the morning hours of Monday. Most likely it won't take up that whole time period, but right now the models are very vague in timing and intensity. Right now it looks like some snow will build in and it looks like a couple inches at most for most people out there. Stay tuned for further updates on the snowfall potential!

~KDLT Meteorologist Aaron Shaffer

Snow Cover...The key player

Warm temperatures are going to be the name of the game over the next couple of days as a ridge of high pressure will be keeping the cold air at bay. But the hard part for any meteorologist is just how warm with things become. Well, this becomes increasingly complicated when you have a significant amount of snow on the ground. Why? Well as you all are very much aware of, snow is white. Because its white, it has a high albedo. A high albedo means that an object is a really good reflector of the suns rays and anything with a low albedo is a good absorber of the suns rays. Because snow has an extremely high albedo, it reflects the suns rays back into the atmosphere and that keeps the temperatures for warming up. So, snow cover becomes very important to a forecaster in the winter months because typically the more snow that's on the ground, the cooler that area will be. Here is a current snow cover map of South Dakota. You can see that many areas across the East continue to have 4+ inches of snow on the ground. Well, that really helps keep those areas cooler. But the places that have little or no snow cover can expect to see temperatures anywhere from 10-25 degrees warmer then areas with a lot of snow. So depending on where you live in South Dakota, today may still feel like winter or it may feel more like spring.

~KDLT Meteorologist Cody Matz

Sunday, January 18, 2009

Chilly Weather Brings Flowers???

While we are seeing a nice warm up in our neck of the woods, folks just to our East are seeing some very chilly temperatures. A mere 17 degrees was the high in Chicago today! A slightly odd phenomena can be witnesses when temps get this cold in regions that aren't used to being this cold. This picture below was taken in Edgemont, Arkansas by photographer Chyenne M. Star.

They are called ice flowers or ice ribbons. Apparently they have been studied for over 200 years and have confused physicists, geologists and botanists. The conclusion that was finally reached was that a crack in a stem exposed the water in the stem to be exposed to the chilly air, the liquid water freezes and expands outward, the process just continues until the flower stem runs out of water. This movie shows it pretty well. A pretty cool treat, too bad it's too cold for flower stems here to still have liquid water in them. If you want to know more you can go to spaceweather.com or check out this website.

~KDLT Meteorologist Jesse Ritka

Saturday, January 17, 2009

Price To Pay For Warm Up

A nice warm up for many places today... even a 50 in Chadron, just a reminder, we are supposed to see temperatures around 25 degrees right now. Where the temps were hovering around freezing is where travel was not pretty. Several roll-overs and accidents were reported along I-29 with the worst being from Sioux Falls up to Brookings. The safetravelusa site had this image on their website:
As for this warm weather, we'll be seeing a bit more of it, so I expect road conditions to continue to be a bit slick tomorrow evening as the sun sets and temperatures cool once again.
This is a map basically showing how far away from average our temperatures are going to be when the map is valid. That big area of blues and purples is the cold spell we went through last week, you can see that it's pushed off towards the East now. The big area of reds and oranges mean warmer weather. So you can expect another day like today and then some even warmer temperatures by Monday and Tuesday.
~KDLT Meteorologist Jesse Ritka