Brief Tornado Warning

A tornado warning was briefly issued for Sanborn County, near Artesian - this is what the storm relative velocity looked like when they issued it, you can see the bright area of red right next to a bright area of green, that's storm motion going towards (green) and away (red) from the radar and is a major indication of rotation in the atmosphere... this is a big reason why the warning was issued. This was only a doppler indicated tornado warning and so far, no reports on if one actually touched down.

We'll let you know later if anything actually formed.

~KDLT Meteorologist Jesse Ritka

Severe WX - It's Here

That cold front is pushing across the state... here's a look at the current situation - the red box is the severe thunderstorm warning, if you click on the picture, you'll see a more detailed description of who's going to see what in the next half hour or so.

We'll watch the area between the areas of precip. fill in as the cold front continues to sag south. Expect this stronger precip. and winds and potentially hail from these storms to reach the Sioux Falls area around 9:30pm tonight.

We've had reports of 1.0 inch hail already in Clark county near Clark along with penny to quarter size hail... no severe wind reports yet, but strong winds anywhere from 50-60 mph gusts are associated with this line as well.

More updates later.
~KDLT Meteorologist Jesse Ritka

Sunday Severe Risk

Pretty much an oval of slight risk right on top of our viewing area, so busy day tomorrow! The day will start out okay as far as temps go, but the winds will pick up from the South and bump up the temps as well as the humidity.This is what to expect as far as dew points go... you can definitely tell that we'll have plenty of moisture from the golf being brought up. Some dew points could be 60 degrees and up, making for a muggy day. This is what some meteorologists call a "moisture ridge" or an axis of high dew points , some also call it a 'moist tongue' which is a key ingredient for severe weather, you have to have ample moisture for storms to spark up.

This is the mean layer CAPE, or Convective Available Potential Energy, basically this is a picture of how much energy is there that can be used to fire up the storms or available for convection. It tells us where there is a lot of potential for upward motion - which is another key ingredient for severe storms. For thunderstorms to happen - we usually need over 1,000 Joules per kilogram and as you can see, a line of over 1500 J/K extends all the way up into our region. For extreme storms you can sometimes see CAPE values up to 5000 J/K. Obviously values aren't THAT high for tomorrow, so that tells us that it's not going to be a huge event with a bunch of outbreaks of severe weather, but keep your eyes on the skies in the late afternoon hours for development of these popcorn thunderstorms along the warm front that will be pushing north throughout the day.

The associated cold front pushes through late Sunday night and into Monday, so we'll see cooler and not as humid weather following that.

~KDLT Meteorologist Jesse Ritka

Strong Storms Update

We're watching tonight as a couple of stronger isolated storms have formed in north-central South Dakota and also north-central Nebraska. As these storms grow they will also start to shift more toward the Southeast.

This is what the latest radar image from about 6:07pm looked like:

You can see a severe thunderstorm warning over Corson county. We'll be watching these guys as they slide toward the Southeast throughout the evening. Don't be too surprised to see a shower pass overhead during the overnight hours toward the SE.

Saturday? Looks amazing for most of us! Expect any early clouds to clear away and leave us sunny and pleasant - with highs in the upper 70s to lower 80s.

Have a great weekend!

~KDLT Meteorologist Aaron Shaffer

Great Weather Now... And Severe Weather Sunday?

We're watching the weather patterns over the next couple of days very closely - and not just because we are hoping to have nice weather stick around (even though we are hoping for that). We're seeing the potential as a cold front moves in Sunday for some at least slightly organized thunderstorm activity - and involved in that will be the chance for some isolated severe storms.

This image below is forecasted precipitation through Sunday night at about 7pm:
You can see quite a large blob of future precipitation over eastern South Dakota and southern Minnesota. While that is not quite representative of exactly where rain will likely fall - it does give us a baseline for where to look for strong storms. Add into that a variable you've probably heard us discuss before: CAPE (Convective Available Potential Energy, or the energy available to help fuel a storm). Look at this image below - and know that basically anywhere a storm forms where there are shaded areas it will at least be a light thunderstorm:

So... your conclusion after reading this post is that: yes, you should expect rain and thunderstorm chances as we conclude our weekend - but no, you should not expect a major severe weather outbreak - at least not yet. We'll be watching just to make sure.

Have a great night & hopefully you can get outside!

~KDLT Meteorologist Aaron Shaffer

Fog This Morning

With the clouds finally clearing out toward sunset yesterday across the I-29 corridor, conditions for near perfect radiational cooling were setting in. Radiational cooling is just the atmosphere cooling down once the sun sets. Well, with clear skies and calm winds last night AND a lot of left over moisture from the several hours of mist we saw yesterday, areas of dense fog developed. This morning many areas are experiencing visibilities at or below 1/4 mile. Most of the areas effected are right down the I-29 corridor as seen in the picture below. The fog this morning was very shallow, only extending to a couple hundred feet off the ground, but very very thick in spots. This fog reminds me a lot of the type of fog that occurs in San Francisco. Here is a picture of fog they usually get in San Fran.

Notice that the fog is thick enough that you can see through it, but the high of the cloud appears to be quite small, 100-200 feet or so. I'm sure some of the areas that have some higher rolling hills in South Dakota may have experienced something very similar.

~KDLT Meteorologist Cody Matz

Cool Weather Leaves... Severe Weather Sunday?

We've been chilly today with lots of clouds - but that hasn't been the case for everyone... and soon enough we'll be seeing plenty of sunshine out there for all. Look at this image below - this is what we call "visible satellite" imagery. That is basically what we use to simulate what we see with our own eyes from space:


As you can see - it was a fine line between warmth and sunshine and cloudy skies and chilly temperatures. Unfortunately - that line didn't really move much throughout the day. That will change for Thursday, though, and we'll see a return to near-80s.

All of this warmth and sunshine helps to fuel some thunderstorms - and that will likely take place toward this weekend. We are closely watching Saturday and Sunday - with a lot of emphasis on Sunday - for any severe weather potential as a cold front glides through the area.

We'll update you on any potential severe weather as the time approaches - but for now just plan on some strong thunderstorms being seen on Sunday.

Have a great night!

~KDLT Meteorologist Aaron Shaffer

Clouds Linger

Looks like clouds will be holding strong again today across areas of the east. Because of that, temperatures will again be 10 to 20 degrees below average. Even I can be amazed sometimes by just how much cloud cover can effect temperatures. Here is a model forecasting temperatures today at 1pm. You can see exactly where the clouds remain because just how cool some spots are, that area is circled in black.The areas that don't have any clouds are well into the 70's making for a pretty big temperature contrast across the upper Midwest today.

~KDLT Meteorologist Cody Matz

Quiescent Conditions: Doesn't It Seem Calm Around Here Lately?

You've probably noticed that in most years we have severe thunderstorm and tornado warnings and watching nearly constantly scrolling across the screen by late-May in this area. That is because we are in a very severe weather-prone region, with some good southerly moisture flowing in and the stronger cold fronts that dip in with larger-scale systems from the West at this point in the year. That happens because there is still a very strong temperature contrast over us that helps to intensify anything.

You likely notice, then, that by about August things get to be just hot and dry - without as many severe weather outbreaks, and then by September it gets cool and cloudy - with an occasional severe storm.

That is the weather pattern we have been in lately. More of a late-summer/early-fall type of weather pattern. Not much flow in the upper levels of the atmosphere in our neck of the woods - with most of the upper level winds happening over southern Canada and toward the southern United States.

This was a quote from a blog post by Greg Carbin of NOAA (full text here: http://www.norman.noaa.gov/2009/05/1137/) talking about the significance of the change in conditions lately - and this quote was from the 22nd:

If the SPC does not issue a watch today or tomorrow, that would be a substantial “first” for this particular week in May. Since 1970, there has not been another May 17th-23rd period without at least 6 watches issued (either a severe thunderstorm watch or a tornado watch somewhere in the country). The SPC has not issued a watch since Saturday evening, May 16, 2009. Since 1970, there have been about 28 watches issued during this week in May. The greatest number of watches ever issued during this week-long period was 59 (averaging almost 9 a day!), in 1989. It now appears likely that SPC will break the previous minimum number of watches issued for the week, 6 in 1976, by Saturday, achieving a record of 0 watches for the week of May 17th-23rd, 2009. That has not happened before and can be considered quite unusual.

Not only is that unusual - but it's also unusual that we have not only met that no watch level through May 23rd, but it's May 26th as I write this and we *still* haven't seen any!

If you consider my comments from earlier, that makes things significant, and there is another quote by Greg where he puts it much better than I could:

It’s still possible that the overall flow pattern can revert to a more typical and active late May weather pattern, thus resulting in more widespread severe thunderstorms and a greater potential for tornadoes. However, the chances of that happening decrease as the summer months approach and the weather pattern, as established, becomes more typical for the time of year we find ourselves in.

All in all - it's been very unusual. We keep getting ready for severe weather in the KDLT Weather Center, but it just hasn't been happening. Don't let this make you less-prepared for severe weather when the time comes - because we get severe weather around here no matter what time of the season it is.

Have a great night and get ready for more sunshine by tomorrow night!

~KDLT Meteorologist Aaron Shaffer

Cool Today!

Unlike yesterday, today will likely be cool, cloudy, and could see a few sprinkles in some spots. It will likely remind you a lot of April as temperatures will run some 15 degrees below average. However, temperatures entirely depend on if the clouds hang around and it looks like they will. A lot of low and mid level moisture stuck in the atmosphere should keep things overcast. Here is what I have looked at to determine this. Below is a series of images that show relative humidity values at 850mb (5000 feet). Typically when the levels are at or above 90 percent, there are clouds. 90 percent is shown by the light blue color.

Noon Today

Midnight TonightNoon TomorrowMidnight Tomorrow NightNotice that this particular model really hangs on to the clouds in the southeast through much of your Wednesday. I think we will start to see them break up a bit tomorrow afternoon across the east as the best dynamics for cloud cover move further east. But it definitely does look like a cool next couple of days.

~KDLT Meteorologist Cody Matz

Heavy Rain Is Here

As I'm writing this, there are already several areas that have seen heavy amounts of rain from this cold front we've been predicting for awhile. Near Turon and Doland in Spink County, already 1.50" of rain has fallen in the past 2 hours. Huron's been seeing a similar story throughout the afternoon along with other cities along this cold front.

Now on the larger scale, this cold front is moving to the East, but if you watch the radar loops, you'll quickly be able to tell that the areas of heavy rain are moving more towards the North.
We also have another system planted in Missouri that's acting almost as a shield to keep the overall progression of this cold front slow. But there is so much moisture in the Eastern half of SD that all of that has to go somewhere so the showers are moving along the cold front but also moving north which basically is why we are experiencing the heavy rains along the cold front. All of the rain and moisture is just continuously moving up the slow cold front making it seem like the same rain is sitting in one spot.

Much cooler air will fill the day tomorrow, and some of these showers will still linger in the SE because this front IS moving so slow.

~KDLT Meteorologist Jesse Ritka

Summerlike Humidity is Back.......For About a Day

Looks like humidity levels are going to increase rapidly today as lots of moisture works into the state. That will help spark showers and storms this afternoon in central South Dakota which will progress slowly to the east through out the day and night. These will likely be into the I-29 corridor in the overnight hours. With temperatures very mild today and an increase in moisture, it will likely get a bit muggy today. To measure the level of moisture in the air, we have the dew point. There are certain thresholds that we can use to determine the levels of humidity using the dew point. For example, a really muggy day vs. a very dry day. Well, below is a chart to explain the relationship between the dew point and when it feels humid outside.Now, I picked this particular image because it shows two different scales; one for people living out west that are not necessarily used to the high humidity, and one for people out east who live with it almost everyday of their lives. But this scale is completely relative and can be different for each person. But in the weather world, there are often too many variables to calculate so we typically just generalize everything. Well, since South Dakota is more of an in between state between the very dry rocky mountains and the very moist east coast, I would put the "South Dakota Dew Point Scale" somewhere in between the one that you see above. So I would say that less than 45 is very dry and then 46-50 is comfortable, etc.

The dew points as I'm writing this are steadily climbing, already into the upper 50's near the Missouri river as seen below.

And you can expect these to continue to climb through out the day. Notice that the forecast model below is saying dew points will be in the low to mid 60's for some of us by 4pm. And if you refer to the chart above, that would put us in the very humid category so drink lots of water if you are planning on being outside today.~KDLT Meteorologist Cody Matz

M-Weekend Forecast Cont.

Here's a look at the current situation... We've got a warm front pushing up from the south and thunderstorms are expected behind it. The Storm Prediction Center even has a "Mesoscale Discussion" out about it:
^ This is the MD, they usually put these out for regions of severe weather and for heavy rainfall, to view the entire explanation of this MD, go here. Basically this one says that some severe weather is possible here, they are mainly concerned about hail and wind gusts. As these fronts slowly move East, they are going to bring a lot of rain across the state... Here's just an estimate for the end of Memorial Monday:

I guess it's a good thing we aren't in North Dakota or it'd be a washout, but we're still going to see some larger rain totals as well. A half inch to an inch in 24 hours, some places could see localized minor flooding as some of these thunderstorms pass by. Looks like Pierre could see around an inch, Aberdeen 1-1.5 inches with lighter amounts surrounding.

Looks to be a dry day for the SE, we could see a few varied popcorn thunderstorms with the daytime heating as temperatures are going to be warmer than they were today as the warm front pushes north.

Enjoy the rest of the weekend!

~KDLT Meteorologist Jesse Ritka

What's Keeping Us Dry?

Well thanks to high pressure, a lot of Memorial Day weekend plans didn't get rained on at least for today! Even those showers in the South dried up for a great dry sunset on this Saturday, hope you got to get out and enjoy it!

Here's what's shaping up for the rest of the weekend, this is the outlook of one model for Sunday:
Once again it looks like showers in the south in the evening, sorry guys, you don't get a break just yet! Though the day will start off dry as that high pressure means sinking air and we're seeing northerly winds streaming drier air down to our region but there's so much moisture being pumped up from the Pacific as well as the Gulf. Basically that bullet of blue in Nebraska is where the two air masses have been meeting and will battle once again in the afternoon and evening hours. More development of a low pressure over the Rockies right now will push that energy and rain north through Saturday evening along a warm front, so Monday will bring warmer weather and drier weather for folks in the South - finally! Here's a look at what to expect around the dinner hour on Memorial day:

The warm front pushes north and we start to see a slightly more organized cold front start to push slowly across the central region of the state. This is a slow mover though, so expect a drier day in the East until the evening as the front progresses. The cold front will still produce rain showers through Tuesday and into Wednesday morning.

Enjoy the dry spots!

~KDLT Meteorologist Jesse Ritka

Memorial Day Weekend

Here's a more regional view of what to expect this Memorial Day weekend, thanks to the Aberdeen NWS for a better travel forecast. Showers are going to be the main story especially south of I-90 for Saturday and Sunday and rain will be more of an issue in the North on Memorial Monday. If you're looking for when that dry weather will hit... here's a breakdown:Keep in mind, these sky conditions aren't going to last the entire day, there's still a chance of rain basically every day until Wednesday, but these days look to be the driest for right now.

Enjoy the holiday weekend despite the chances for rain!
~KDLT Meteorologist Jesse Ritka

Moisture Streaming In

Some more rain showers out there this morning mainly for Iowa and southeast South Dakota. Here is a current look at these showers.These are all being produced by a stationary boundary that is in northern Nebraska. The clash of two air masses and a moisture funnel that works its way in all the way from portions of Mexico. Big ridge of high pressure in the Southeast United States and a clockwise rotation of the air around the high and that funnels moisture into the upper Midwest. But there is a high pressure to the north squeezing that narrow band through southern South Dakota and northern Nebraska. All of this can be seen in the water vapor image below. Remember dark whites and colors indicate lots of moisture and the black areas indicate very little moisture.

And this funneling effect to the moisture looks like will stay with us through the first half of your Memorial Day weekend so be prepared for some occasional showers in the south and southeast.

~KDLT Meteorologist Cody Matz

24 Hour Difference!

Okay, first, I'm sorry to put this up this late; I thought I saved the 24 hour map from 6pm today, but this map from 9pm will still work I suppose, it gets the idea across that we're much colder than we were 24 hours ago. The cold front that brought round number one of rain chilled our temperatures incredibly! Yesterday we were in the 80s and 90s, and our temps dropped 20 to 30 degrees compared to yesterday, highs today were only in the 60s! Brrrr, or so it felt after the 90s. Hopefully you got enough of the really warm weather these past few days because we're going to be seeing a lot of clouds over the next few days along with a good shot of spotty showers across the region, especially in the South in the immediate forecast. Here's a general overview of what to expect:
Like Cody said, it's not going to be a washout, but you'll be dodging showers throughout the entire weekend. Here's what to look for tomorrow as far as total precip throughout the entire day: For the most part we're looking at another tenth of an inch to a quarter of an inch in the southern half of the state. Looks dry in the north though, so you'll dodge this round, keep tuned for what to expect each day this Memorial weekend.

Stay dry!
~KDLT Meteorologist Jesse Ritka

Scattered Thuderstorms Through the Weekend

Looks like the weather pattern has changed from the last few days because it will be cooler and there will be some rain around. Doesn't look like a wash out on any day but you may have to dodge a shower or thunderstorm on occasion. The Hydrological Prediction Center (HPC) makes a forecast for amount of precipitation expected over the next five days. The image is located below.Even though we aren't expecting a wash out, it does look like some of that rainfall will begin to add up as many areas can expect one to two inches of rain between now and Tuesday morning. That may sound crummy but that's actually good news for farmers because many of them have been able to get their crops in the ground and now they are looking for some rainfall. It will also be good to get some rain because Sioux Falls is well below average on the year. According to the graph below, we are already over 2 inches of rain below average so some more is needed.

~KDLT Meteorologist Cody Matz

Memorial Day Weekend Sneak-Peek

We're looking toward Memorial Day weekend as we head into the last half of the work-week. There is quite a bit of unsettled weather that will take place between now and next Monday - but we all want to know what to expect for Memorial Day. As such, we've pulled a couple of images showing model predicted precipitation on Monday evening. These two agree - but between now and then they really don't. They just show various patches of rain floating through the area between about Friday and Monday morning.

You can see rain edging in from the West by Monday evening - with most of it in the western half of South Dakota. This model image is from the model I typically would put a good amount of faith in. On the other side, we have the European model - another one that is very good on a regular basis:

Both of these images are for approximately 7pm on Monday night. Both of them show rain. The European model is showing rain a little bit quicker to the East toward Monday night.

The bottom line? Don't cancel your barbecue just yet. Things will likely sort themselves out by Friday, if not by Thursday.

Have a great night!

~KDLT Meteorologist Aaron Shaffer

Warm Again Today

Another warm and windy one today as highs will likely be back in the 90's across the southeast. A wind advisory is in effect for areas of the east as gusty winds will kick up again today. I have seen gusts already this morning topping 50mph. All of this near record heat will come to an end later tonight as a cold front and showers move in. Below is a series of images that shows the probability of rain over a three hour period starting from 7pm and going until 10am tomorrow.So the first image the probability that we will see rain between 7pm and 10pm tonight and so on. Looks like the best chances for rain tonight for Sioux Falls will be in the overnight hours between 1am and 7am.

~KDLT Meteorologist Cody Matz

Early May Heat... And A Cooler Memorial Day Weekend?

Things have been mighty hot around these parts the past couple of days - and that looks like it will continue for Wednesday as well... as we wait for a cold front to move through the area. We did some research both on our own and through discussions with helpful members of the National Weather Service office in Sioux Falls - and found a large wealth of information that may interest you... such as the last time certain areas saw temperatures at 100 or higher:


Now, we didn't quite get near 100 in the Sioux Falls area - but we did see our 2nd day of 90s so far this year. Pretty impressive, considering the fact that we didn't hit 90 or higher that many more times last year.

So... by looking at the image above - you might come to the conclusion that last year we really didn't have that many extreme heat days... with the average number being 22 days with 90 or higher for highs in Sioux Falls...

Storm Chances & Cooling For Memorial Day Weekend

As we mentioned in the title - there is some cooling on the way that will arrive in the form of a cold front for Wednesday night into early Thursday. That leaves us unsettled for the weekend - with some dry and sunny patches mixed with some shower and thunderstorm chances.

If you look closely at the map above showing computer forecasted temperatures for Sunday - you see upper 60s to lower 70s. Assuming the unsettled weather becomes more settled - we could end up with some beautiful weather. If the computer models & their forecast for clouds & shower chances come true - we could see a more gloomy and cool-feeling weekend.

Stay tuned over the next couple of days!

~KDLT Meteorologist Aaron Shaffer

Warm and Windy

Another warm one across the state today so have the sunscreen and water bottle handy if you are spending more then a few minutes outdoors today. Thankfully will be at least 5 degrees shy of record highs so wont have to worry about that. But regardless, it's still going to be hot. However, one of the models is actually hinting that temperatures could be several degrees warmer then we are anticipating which would bring them very close to record highs. Here are the temperatures its predicting at 4pm.The part of this map that stands out to me the most is that pink dot in south central South Dakota, that signifies the 100 degree mark. Wow, that's crazy warm. I don't have any temperatures quite that warm in my forecast but this shows that the potential is there for even warmer weather.

Its also going to be windy, especially across the south with winds sustained anywhere from 20 -30 mph. Here is what we are looking at. Take note of the wind shift line, that's the cold front that moved through overnight retreating back to the north.

~KDLT Meteorologist Cody Matz

Warmth & Tornado Study Update

Things have been pretty warm today - it's been impressive & even passes up some of our higher temperatures we had been talking about for today last week. We were expecting some lower 80s for Sioux Falls as of the end of last week - and now we're at 87 degrees as of me writing this blog post.


We're looking for warm air to hang around for Tuesday and even into Wednesday - despite a weak cold front trying to move in from the North Tuesday.

Also, we've had a few stories or mentions of the VORTEX project around the area - and found a fun story about them coming to a small town to visit. You can watch it below.

That's it for now! Have a great night!

~KDLT Meteorologist Aaron Shaffer