Monday, November 30, 2009

Not Just Cold But Also Windy

I hate to add insult to injury, but not only are we going to be falling off a cliff so to speak, as Jesse said in her blog, its going to be a windy journey on the way down. The winds over the next three days will really be something to talk about. Its been a while since we have seen several windy days in a row AND its been 8 or 9 months since we have seen temperatures as cold as what is forecasted. So we are in for a rude awakening. Here is a model that forecasts the probability of wind speeds at different thresholds. In the top left is the probability of seeing winds calm. In the top right is sustained winds of at least 15 mph. In the bottom left is sustained winds of at least 25 mph. And in the bottom right is sustained winds of at least 35 mph.

Tuesday Afternoon:Wednesday Afternoon:Thursday Afternoon:
When we are talking about winds and the temperatures being as low as we are expecting, then we also have to focus on the wind chill. The wind chill is what it feels like outside when you combine temperature and wind speed. Looks like right now we can expect wind chills in the single digits and teens over the next three days so break out the heavy coats, gloves, and hats because old man winter is on his way here.
~KDLT Meteorologist Cody Matz

Cold Snap on the Way!

So I really think this forecast reminds me of when I was little and watched the Price is Right. The 7 day forecast is really similar to the Cliff Hanger game except we can't control the cliff hanger man (in the forecast sense... temperatures) from dropping off that cliff. The 7 day forecast temperatures will increase in temperatures today and tomorrow before dropping significantly by Wednesday. 50 degrees on Tuesday down to 33 degrees on Wednesday is going to be a cold enough snap as it is but you factor in the winds that are associated with this cold front that will move through on Tuesday night and we're going to have some very cold wind chill temperatures. If you don't believe me about the winds... just look at Cody's last post below at the wind barbs... OUCH! Tomorrow will definitely be the warmest day in December, and watch those temperatures get sliced in half by Thursday.

Enjoy the next two days before the big bundle up!
~KDLT Meteorologist Jesse Ritka

Sunday, November 29, 2009

Is the last 4 months of weather any indication to whats going to happen next??

The last couple of years have really been quite something across the state; from record breaking snowfall in the Black Hills this past winter to two back to back unusually cold summers. Two very wet springs in a row, the coldest and wettest October on record just one month ago, and now what could be the warmest November on record. We have almost seen it all in the last couple of years but are there any indications of whats to come in the future? There could be. Meteorologists try to take into account absolutely everything when making a forecast, from soil temperature, to sun angle, to the amount of mixing, to sunshine, to climatology, we literally try to look at everything. Well there is one thing that can often lead us to the right direction, and the answer may more simplistic then you think. A Pattern! Just like everything else that we know of, the atmosphere goes through cycles. There are several that we know will happen every year, the change in seasons, tornadoes, hurricanes, monsoon, and even nor'easters, they all have a specific pattern they follow. That's often how they are not forecasted, both when they will occur and where they occur. Some are obviously more precise then others. But we can also find some less obvious patterns. Take for instance the last four months in Sioux Falls. The month of November has been extremely warm, October was extremely cold, September was above average, and August was below average. Are we seeing a pattern?? The months seem to be switching back and forth like clockwork, one will be cold and the next will be warm. Here are the numbers.
November: Average Monthly Temperature: 41.8
Departure from Average: +10.0
October: Average Monthly Temperature: 42.4
Departure from Average: -5.6
September: Average Monthly Temperature: 63.4
Departure from Average: +2.5
August: Average Monthly Temperature: 68.0
Departure from Average: -2.8

So, now the question remains, will this pattern continue? Well, The KDLT weather team thought it probably would. Well, lets see if we are on the right track. And all you have to do to see if we are is look at the first week of temperatures for December on one of the forecasting models You will likely figure out that the pattern will continue, at least for a while. Check it out.

850mb Temperatures for Monday (the last day of November):
Tuesday (The first day of December):Wednesday:Thursday:So you get the idea. But what about the long term, say next week? Here you go!

Next Wednesday:
If this model were to come true for next Wednesday, then these 850mb temperatures would likely spell highs right around zero. Yikes!! So it looks like the pattern will continue, well at least for the near future. But will it be that cold for the whole month? I guess we will just have to wait and see!!

~KDLT Meteorologist Cody Matz

Thursday, November 26, 2009

Its November?

How often do you get to see highs like these for black Friday?? Its been a while since black Friday has been this warm.Enjoy these temperatures because with December starting on Tuesday, there are likely very few mild days left before the start of winter.

~KDLT Meteorologist Cody Matz

Black Friday Forecast

For those getting up early to catch the Black Friday super sales... here's a look at the overnight low temperatures during the overnight hours. If you're going to be driving to the mall, conditions will be mostly clear with a few clouds and light winds.Keep in mind, temperatures will be falling and end up at these temperatures right before sunrise, so if you try to catch a 4am sale, it will be a little warmer than these temperatures.

It will be a bit warmer than in years past, we're supposed to have temperatures well into the teens at this time in November, but cold is cold.

Bundle up and good luck getting those deals!
And Happy Thanksgiving!
~KDLT Meteorologist Jesse Ritka

Wednesday, November 25, 2009

Warmer Friday But When Will the Cold Be Here to Stay?

If you didn't enjoy the weather on Wednesday then just focus on whats in store for us the next three days! Much warmer weather is coming to a city near you. Looks like temperatures will start their climb tomorrow and peak on Friday with highs some 20 degrees above average for many places. Then we will start to cool back down on Saturday. Just look at the warmer air heading in our direction:

850mb Temperatures for Thursday Afternoon:
850mb Temperatures for Friday Afternoon:850mb Temperatures for Saturday Afternoon:So when are the winter like temperatures here to stay?? Well, that's always a tough thing to predict because its never the exact same time every year. However, there are many sources leading me to believe that the date for the permanent cold may be approaching soon. First, some of the middle ranged models are showing a pretty substantial cool down late next week. Second, the Climatological Prediction Center (CPC) has issued there daily forecast for the next couple of weeks stating that there is a pretty high likelihood that next week and the week after would be below average. If this is correct, then our highs would likely be in the 20's with lows in the single digits. Check these out;

These are 850mb temperatures for late next week and next weekend. Looks pretty cold to me!
This is the forecast from the CPC. The blue colors indicate higher probabilities of temperatures being below normal. The first is 6-10 days out. The second is 7-14 days out.Hopefully you get enjoy the temperatures the next three days because 50's may be something we don't see again until spring!!
~Meteorologist Cody Matz

The "Magic Line"

Since Cody didn't fill you all in on the "Magic Line" . . . I will :) When we are forecasting for snow, like we're seeing today, there's a line we look for, it's called the 540 line. The 540 corresponds to 5,400 geopotential meter thickness of the atmosphere between 1000 and 500 millibars. Basically warm air takes up more space in the atmosphere than cold air does, so when we've got warm air in place, our thicknesses have higher values. (think of how a balloon gets smaller when you take it from hot air to cold air) Check out this experiment below if you want to see it in action for yourself - fun thing to do with the kids.When cold air moves in, the thickness of the atmosphere decreases and the 540 line is somewhat a guide as to when the air is cold enough to produce snow showers instead of rain showers. If that doesn't make much sense and you'd like it to, check out Jeff Haby's site, he goes more in depth when it comes to thickness. But basically the more thickness decreases in the atmosphere, the better chances there is for snow. And the 540 line is the thickness that normally separates rain from snow showers to occur.

So when we're looking at the models to figure out the forecast we look for this magical line first to see if there's a possibility of snowshowers. If the thickness is less than 540, that's even colder air, so there's an even better chance for snow versus rain showers. With the thickness line at 526 around our area today... we're going to stick with mainly snow today that will exit by the evening hours, just in time for Thanksgiving!

Enjoy Thanksgiving Eve!
~KDLT Meteorologist Jesse Ritka

Tuesday, November 24, 2009

A White Thanksgiving??

Not quite all white for Thanksgiving, but we are expecting some snow showers tonight and into Wednesday bringing mainly under a half an inch of snow to some areas. Here's a look at futurecast: This is part of a system that will slide southward from Canada bringing in a major shot of cold air, so brace yourself for temperatures to return to where we're supposed to be for this time of the year, into the mid-30s. The dashed lines in blue basically show cooler air, where there are those blue dashed lines many times shows where the precipitation type is snow instead of rain... maybe Cody will let you know more about these "blue lines". Or else I will tomorrow :)

~KDLT Meteorologist Jesse Ritka

Monday, November 23, 2009

The Winds of Change

It may begin to feel more like November around here as it we will probably see a couple cold shots of air make their way through over the next week. The bad part is that not only is it going to be cold, but it will be windy as well making it feel so much colder. One shot of cold air is set to make its way in on Wednesday and stay through Thanksgiving. Then a brief warm up for you Friday and Saturday and then another shot of some cold air on Sunday and Monday. The funny part is that temperatures will be right around normal for this time of the year. But we have been so warm lately that it will probably feel unusually cold.

850mb temperatures for Wednesday afternoon:
850mb Temperatures for Friday afternoon:850mb Temperatures for Sunday afternoon:To sum it all up, areas of rain tomorrow. Some flurries, wind and cold Wednesday. Warming Thursday through Sunday and dry. Then, cold Sunday and Monday with a few snow showers possible. What a topsy turvy way to end November. Is it Spring yet???

~KDLT Meteorologist Cody Matz

Sunday, November 22, 2009

Rain is Coming But Not for Everyone

Looks like we will be seeing some rain over the next couple of days. But not everyone is going to get wet. The rain will likely be confined to the I-29 corridor and points eastward. The models have really increased the amount of rain that they think we will see over the last 24 hours and in some cases doubled and tripled it now. For the most part, none of it will be all that heavy but some areas could really begin to add up by Tuesday night and Wednesday. Here is what a couple of the models are predicting for the upcoming couple of days.

Rainfall Totals through Monday afternoon:
Rainfall Totals through Tuesday morning:
The stationary boundary can be seen on this map. The wind barbs in far eastern South Dakota are coming out of the northwest and the wind barbs in far western Minnesota are coming out of the south southeast. This is indicative of some sort of boundary in between those areas. In this case the stationary boundary I was talking about:
Notice that there is a pretty small area that will be seeing the rain through Tuesday morning. But I'm sure you are wondering why all of the rain is in a straight line right over I-29. Well it looks like the focal point for most of the rain will be a left over stationary boundary. The model has it stalling north to south right over I-29. However, I do think that the model is putting too much emphasis on the stalled front so I think there will be showers a bit more widespread then what the model shows. Case and point; look at what the Hydrological Prediction Center has for rainfall amounts between now and Wednesday night.They have the most rain falling just south of Sioux City at nearly 2". Now the HPC is typically on the high side of potential precipitation however, 1" of rain is definitely possible in isolated spots. But a quarter to a half inch will probably be a lot more common.
~KDLT Meteorologist Cody Matz

Saturday, November 21, 2009

New Cloud Type

Okay, so this isn't exactly news... but since we haven't written about it on here yet and Cody wrote you a book about how models and ensembles work (and the models are still not in agreement about this next storm yet)... I'm going to let you all know about a new cloud type that is on it's way to being classified. The clouds are called Undulatus Asperatus. They are very rare, but a lot of people get a bit freaked out by them because of their ominous appearance, you can see why. These are now on their way to being officially classified as a unique cloud type because they are different from other undulatus clouds. They would be the first new cloud formation to be added in over 50 years. The clouds actually dissipate before storms form, despite their dark and threatening appearance. They are usually seen in the Plains (you probably have seen them before, mainly during the morning or middle of the day) and they usually form after thunderstorms, and we get plenty of those during the summer. The Royal Meteorological Society is currently gathering evidence for how these clouds form to decide if they shall officially be classified as a new cloud type.


I actually think they kind of look like Vincent Van Gogh's "The Starry Night" from 1889.

Maybe they were his inspiration over a century ago... anyone else?

~KDLT Meteorologist Jesse Ritka

Friday, November 20, 2009

Using a Model to Forecast and Why its so Difficult

Forecasting for weather is a tricky business. First of all, its not an exact science and probably never will be. There are just too many variables in the atmosphere. Some can be seen by the human eye but most cant. What we don't see, forecasting models try to see for us. However there are so many unknown variables in the atmosphere that it can be nearly impossible to paint a correct picture, but we do our best. Forecasting models take as many variables as it can see and paints a picture of what the current conditions look like for the entire United States. Then it tries drawing a forecast from by using them. But it doesn't run only once. Many of them will run a single forecast with the same variables several times and will get a different result every time. Then it takes the sum of all of those forecasts that it produced and averages them out to create one linear forecast.
Hopefully you can see how this would be a problem. Taking all of the accumulated forecasts and averaging them together removes all of the outliers like the extreme highs and extreme lows which can be correct from time to time.

For example, say for instance that there is a storm system that's headed toward Sioux Falls. This imaginary forecast model that we just completed runs 12 times before averaging out its forecast. Well, more then likely, all 12 model runs will come up with a different amount of rainfall that we are going to receive. So here are the twelve numbers; 0", .01", .02", .04", .05", .08", .16", .17", .19", .22", .29", and .86". So if you average out these 12 numbers, you get .17". So this model will tell us that Sioux Falls is going to get .17" inches of rain.

Now, what I hope you are thinking now is that there is a very large difference in those numbers. The model tried to average it out to give you the best possible result. However, what if the outlying model run was correct and we get .86"? Well then this is where meteorologists often make their mistakes. That's why we give probabilities on the chance of it raining. Because if we were to see all of those numbers and see that all of the model runs thought it would rain with the exception of one, then we might give an 80% chance of rainfall.

Well, we are having the same issue with the upcoming week. Some models are saying that we are going to see quite a bit of rainfall while others are saying that we wont see anything. If you look at the individual forecasting runs that were produced by each model (called ensemble members) they all look very different. This is what one such model looks like;
Each box represents an ensemble member. All are for the same period and give total amount of rainfall. Notice that many are very different. Then when the model itself sums up the numbers to output an average forecast for the world to see, it will give you something like this;I have shown something like this many times before. It just simply shows what the average amount of rain will fall by combining all of the ensemble members. This is where the meteorologist will come in and combine his or her knowledge to determine whether or not to trust this model and believe that its giving you an accurate forecast. So at this point, it looks like we will see some scattered showers by Sunday and Monday but we kept the probability of rain at just 30% because many of these models don't agree with each other. So stay tuned because model accuracy tends to get better as the storm gets closer so we will keep you informed with the latest!

~KDLT Meteorologist Cody Matz

Fine Today, but Winds on the Way

Today will be the best day in my opinion out of the entire 7 day forecast, even though temperatures will be warmer tomorrow. That's because today the winds will stick around 5 miles per hour, changing direction from the NW to being from the South. Tomorrow, it's going to be a different story. Here's a look at peak wind speeds on our Futurecast Wind Speeds for Saturday:The middle of the day is when winds are going to peak around the 20-25 mile an hour range. We'll see some gusts up to 30, even 35 miles per hour as well. So enjoy the warm weather but hold onto your hats and ladies - maybe a little extra hair spray will be needed.

~KDLT Meteorologist Jesse Ritka

Thursday, November 19, 2009

Warm Here But Cold Elsewhere

It may be very warm in South Dakota for this time of the year, but it is extremely cold in other parts of the country. This is pretty typical, when one area of the globe is extremely warm, another one will be extremely cold. It is earth's way of trying to balance out the temperatures the globe's temperature. Well it can work on a smaller scale as well. So there is usually a direct link between our weather and Alaska's weather. If we are extremely warm and dry then typically Alaska will be very cold and wet and vise versa. Boy has this been the case. Temperatures here have been ranging 10-20 degrees above average the last couple of weeks. Well Alaska went into the deep freeze this past weekend with temperatures some 20-40 degrees below normal. Just look below at the last three days of highs and lows in North America. The lows are on the left and the highs are on the right (If you click on the images, you will be able to read the numbers).



Realizing its Alaska, 40 below zero doesn't sound that unusually cold, and its not. But they will typically see those temperatures in the middle of January when many areas haven't seen daylight in a month or more. These cold readings are a good 6-8 weeks early and many areas up there are seeing one of the coldest Novembers in the last 30 years. So just remember how lucky we have it right now because I'm sure our temperatures will look like that sometime this winter. At least for us, it's only a few short weeks out of the year.

~KDLT Meteorologist Cody Matz

Wednesday, November 18, 2009

Occluded Front

Since this warm trend continues, and I think everyone fully understands that we're above average and we're going to stay that way for the rest of the week. The one thing that will really influence our weather this week is the area of low pressure that's in the Ohio River Valley.

The fushia (pink-purple) line you see in the comma shape is the occluded front that's associated with this area of low pressure that's caused over a foot of snow in Kansas and several inches of rain elsewhere. While it may seem like this entire system is stationary, it's not. Occluded fronts have movement too. Let's take a second to talk about fronts to find out more about occlusions. First, frontal boundaries are usually attached to an area of low pressure - and normally there is a warm and cold front associated with a low. See the pictures below. Warm fronts bring in warm, moist air behind it and are relatively slow moving. Cold fronts bring dry, cold air behind them and are faster moving than warm fronts. Since cold fronts follow warm fronts and they are more rapidly paced, cold fronts occasionally catch up to warm fronts. When the cold front catches up, it forms an occlusion, where the cold front will "lift" the warm front up and over the cold air. Making the weather ahead of the occluded front feet like warm front weather - slightly warmer temperatures with rain shower. Behind the occluded front it feels more like cold front weather - cooler temperatures with rain showers and snow showers possible if the temperatures are cold enough.

This area of low pressure will push back towards the eastern side of the state, bringing clouds and slight chance of drizzle into our forecast tonight and into tomorrow morning, mainly to the east of I-29 and to the south of I-90. Again, just a slight chance of a sprinkle - not going to tip the buckets.

~KDLT Meteorologist Jesse Ritka

Tuesday, November 17, 2009

Listen to the Leonid Meteor Shower!

If you watched KDLT news tonight, I totally talked way to much about the meteor shower and I plugged the blog. Well if you are here to see, or hear rather, a live audio feed of a leonid meteor crashing into earths atmosphere then you just have to do a little scrolling because Jesse Ritka has it in here post which is the one right below this one.

If you want to know more of how all of this works then click HERE!

And if you want to listen again to the meteor that you heard during the 10pm newscast then click HERE!

~KDLT Meteorologist Cody Matz

Leonids Peak TONIGHT!

Can you tell I'm excited??? I love meteor showers - I remember when I was in middle and high school, I used to stay up with my girlfriends during sleepovers just to watch the meteor showers. Call us nerds, my "nerd-dom" started early, but we thought it was one of the coolest things to check out. I grew up in rural Minnesota, so we were far enough from the city lights, so viewing these meteor showers was just amazing. We'd lay out the blankets, bring the snacks and pop out and lay with our heads in a circle in our sleeping bags to chat and watch the show. All of the showers we stayed up to watch weren't as brilliant as this one is supposed to be. Many are saying we could see up to 100 meteors per hour, though other astronomical forecasters are saying we'll only see 30-40 per hour, still a huge amount! If you know anyone over in Asia - that's where viewing will be the best - over 200 meteors per hour! So where does this meteor shower come from? As the Earth is turning and in it's orbit around the sun, we're passing through an area of debris from the Comet Tempel-Tuttle right now.

And did you know you can actually HEAR meteors??? SpaceWeather.com has set you up to actually LISTEN to meteors! It's called Meteor Radar: "The Leonid meteor shower is underway. You can listen to the shower even if you can't see it because of clouds or daylight. The Air Force Space Surveillance Radar is scanning the skies above Texas, and when a Leonid passes over the facility--ping!--there is an echo. Tune into Spaceweather Radio for a live audio feed."

Pretty neat stuff I think, hopefully you can catch it tonight - 1am is when things will really pick up, but bundle up - another chilly night tonight.

~KDLT Meteorologist Jesse Ritka

Monday, November 16, 2009

Grass is still Green?

Despite the fact that the nights have been chilly lately, its been a very warm November so far. You can tell that it has been an extremely warm last couple of weeks because there are still scattered and even numerous areas where plants as well as the grass is still green. There are many plants and grasses that are very strong and can handle quite a bit of cold weather. Case and point, we have had a dozen or so hard freezes and things are still green. Well this is because the ground is not yet frozen. Many of the plants that are still green don't go into a hibernation stage until their roots are cold enough to freeze and the ground just isn't that cold yet. Take a look at today's soil temperatures.
Soil Temperatures at 2" deep:
Soil Temperatures at 4" deep:Now keep in mind that this time of the year, the lower you go in the soil (to a certain point), the warmer it will get. Often times in the middle of January when air temperatures at the surface are 10 or 20 degrees below zero, you can dig 4 or 5 feet into the ground and the soil will be close to 50 degrees.

~KDLT Meteorologist Cody Matz

Southern Low - Rain and Snow

While many of us will see mostly sunny skies today, it's a majorly different story down to our south. Snow showers in Nebraska and Kansas with rain showers in Missouri and Iowa. This will bring some clouds to the SE tip of SD and into Nebraska, Iowa and Minnesota today and tomorrow.

The models are somewhat split in what's going to happen with this area of low pressure responsible for all the wicked weather down there. Taking everything into account, I think this area of low pressure will move somewhat like this: If you follow the arrows, the progression of this system is slow, but I do think that by Wednesday that low pressure will be affecting our forecast. I don't think that it will bring us the same troubles it is to Nebraska and Kansas however. By the time it reaches us, we'll see just a few light rain showers in SE SD and NE and IA. Nothing that will fill up the rain buckets, but something to keep on the radar. (No pun intended there)
Enjoy the mild, dry weather in the meantime,
~KDLT Meteorologist Jesse Ritka

Sunday, November 15, 2009

Watching Storm to our South

Remember the pesky storm that we said is going to develop and hopefully stay to our south?? Well it finally formed and is dropping heavy snow and rain to our south, however, models are still having a really hard time figuring out where it is going to go. Our very own futurecast thinks that the southeast may receive a few rain and snow showers on Monday afternoon and evening. However, there are other models that insist the precipitation will stay to our south. These pictures are from the exact same time period from our futurecast and from another forecasting model. Both speak very differently about where this storm is going to go. Because of the unique nature of this storm (it is cutoff from the jet stream which is the steering mechanism for everything in the atmosphere) it is extremely difficult to decipher where this is going to go. So for now, we are going to keep the slight chances of rain or snow in the forecast for the southeast. However, this may change in the up coming weathercasts so stay tuned!!

~KDLT Meteorologist Cody Matz