6/26 - 10:40am MDT - Another Day, Another State

Yesterday near the Black Hills of South Dakota we saw a few storms develop but they never got organized enough to be good for chasing. One storm in particular had some promise but it just couldn't get strong enough to leave the elevation of the Black Hills where its updraft was rooted. Today we're going north from the Black Hills and moving into North Dakota where there should be a threat for severe storms this afternoon. In particular, areas near and just west of Williston, North Dakota into extreme Eastern Montana appear to be under the greatest threat since a few isolated storms could produce hail, wind, and maybe even an isolated tornado. The Storm Prediction Center only has a general thunderstorm risk for this area but there's a 2% tornado risk included. You'll see the Slight Risk up there in Montana as well in the map to the right, but that area is very remote and the surface winds likely won't cooperate as well for storms like they will in North Dakota.

Winds aloft are forecast to be stronger in our target area today than they were yesterday in South Dakota since the upper-level disturbance over the northwestern part of the country will be moving east a little. When you couple these stronger southwesterly winds aloft with southeasterly winds at the surface that can create some shear for rotating storms. It's worth noting that the best surface winds could be in Canada just north of North Dakota and Montana since an area of low pressure will be spinning winds around from the east there. Since we can't go to Canada, that's obviously out. Dew points in North Dakota are downright soupy this morning and will likely continue to be that way through the afternoon. Having 70 degree dew points right on the Canadian border is something you don't see too often.

With all the warm air and moisture in place, instability will be plentiful for storms. I talked about the threat of isolated tornadoes today on the SPC's outlook and that may very well verify if the instability and shear come together. A great way to combine those two factors is to look at the Energy Helicity Index, which starts getting higher in an isolated spot in Western North Dakota according to the RAP Model. We'll see if it's enough to get some good storms going this afternoon and evening!

Keep up with our chase today by following me on Twitter and Facebook!

6/25 - 10:30am MDT - Great Faces. Great Places.

Today's blog post title is the South Dakota's state slogan. As you can probably gather by that, we're in South Dakota today! Southwesterly flow aloft at 500 mb (18,000 feet) will be present in the western half of South Dakota, northwest Nebraska, and Eastern Wyoming today as the general pattern we dealt with yesterday continues. While the winds aren't terribly strong, the RAP model is beginning to pick up on an area of enhanced speeds near 30-40 knots around parts of Western South Dakota and Northwestern Nebraska. If this enhanced area verifies there could be some better storms under it.

At the surface right now there are southeasterly winds across this area, but the more easterly of the wind vectors are favoring Western South Dakota right now. We'll see how this develops throughout the day as surface conditions continue to change. We'll want these more easterly wind vectors becuase they'll contribute to low-level wind shear that could possibly lead to rotating storms, should they form.

I say "should they form" because we're still dealing with some very warm temperatures aloft. These warm temperatures aloft, called "the cap", inhibit storm development because rising air parcels can't continue to rise buoyantly if the environmental air around them is warmer than they are. The good news here is that temperatures at the surface today will again be in the 90's to near or above 100 degrees. This will really heat up these surface air parcels so that they might shoot through the cap. All models I've looked at this morning have the cap breaking at some point in the early to mid afternoon, but where exactly this happens is still in question. The 14z RAP model has an interesting hole in the cap at around 4pm near Rapid City, but our current thinking is that the Black Hills near Rapid City will be a focus for storm development because they are a constant source of lift and thus a typical location for storm initiation.

To get some of the heating we'll need for storms to form today, we need to have a plentiful supply of sunshine. Right now we do have a layer of clouds over South Dakota that is inhibiting this right now, but western parts of the state are clearing out and it should hopefully leave us with blue skies later this morning. Storms should form sometime after 3pm this afternoon should things come together as forecast. The main threats will be wind and hail from any storm that forms, but we'll be on the lookout for some rotation in these storms as well. The Storm Prediction Center has a general thunderstorm risk for our target area today, but also mentions a 5% severe wind and hail risk.

Follow me on Twitter and Facebook for the latest updates this afternoon!

6/24 - 10:35am MDT - The Chase Begins!

This morning we're heading toward Cheyenne, Wyoming from Denver as we continue to look at weather data coming in. Today's setup still looks marginal by most accounts, but there are a few small features that could cause a few isolated storms to go severe. For one, surface winds out of the east in Wyoming, Northeast Colorado, and Nebraska will generate upslope flow, which is the lift mechanism we need to get storms going.

These winds will also create some shear because they will be interacting with southwesterly winds at 500 mb (18,000 feet). The issue with this is that the faster winds at this level will be further north toward Rapid City, South Dakota instead of where the more favorable surface winds will be just to the south. In any case, the wind direction at 500 mb will be good enough to usher in the wind shear and maybe some drying of the air at that level to increase instability.

When you put the expected helicity (caused by wind shear) and the instability together for today, you get the Energy Helicity Index (EHI). According to the 14z RAP model, the EHI may try to ramp up a little bit in Northeast Colorado and it even breaks out a little bit of precipitation just west of there too. Surface heating is going to be massive since temperatures will be in the 90's and 100's in some places, so we're hoping this also helps overcome some of the warm temperatures aloft (the cap) so that isolated storms can develop. We're grasping for small features today since there isn't any one thing jumping out to get our attention, but so far it looks like a storm or two could fire on the elevation near Cheyenne. We'll also be watching an area closer to Rapid City, SD to see how things develop up that way.

Follow my continuous chase updates on my Twitter and Facebook accounts today!

6/23 - 11:30pm MDT - Who's Ready to Go North?

Our tour guests have been through orientation and now we're ready to set off for our northward journey tomorrow from Denver to the region where Wyoming, Nebraska, and South Dakota meet. This area will be on the northwestern side of the large ridge in the middle of the country and on the eastern side of the trough coming onshore from the Pacific. This means there will be southwesterly winds aloft, at 500 mb or 18,000 feet, to hopefully bring in some drier air so that instability will increase when it contrasts with the warm, moist air at the surface that will be rising into it. While weak in speed, the winds up there will also increase wind shear because they will be at odds with the easterly and southeasterly winds at the surface. This will increase helicity a little bit, which is a corkscrew-like rotation in the atmosphere that is good for fueling rotating thunderstorms.

Moisture shouldn't be too big of a deal since dewpoints will be in the 60's, but we'll be eying the potential for issues with the the cap, which is a warm layer of air above the surface that inhibits thunderstorm development. All the warm air in place over the central part of the country breeds strong capping since the warm air is in place at the mid levels, but the models are suggesting that this cap may be overcome tomorrow afternoon and lead to some isolated storms. At this point there is nothing that suggests any storm that forms will be anything past marginally severe, but the helicity that the NAM model is picking up on above is certainly worth keeping an eye on.

The Storm Prediction Center has a general thunderstorm risk out for our target area tomorrow with no chance for severe weather. Since storms will be pretty isolated and in a fairly unpopulated area, it may not be worth it for them to issue any sort of severe risk with a setup this marginal. We'll see how things have developed overnight when we set out in the morning though. A secondary low may try to form in western South Dakota tomorrow according to the NAM and that may influence our decision on where to go if it forms since the best winds will be just to the north of the low center. Hopefully we'll see some storms!

Follow me on Twitter and Facebook for the latest tomorrow!

6/2 - 10:45am CDT - South Dakota Today, Not Looking Very Promising

We saw a small supercell last night near Valentine, Nebraska with a very picturesque sunset behind it. Since there were no road networks in the area we had to stay a good distance away from it and unfortunately it didn't last long either. If it had developed a couple hours earlier it would've been a big storm!


I'm no fan of today's severe weather setup in South Dakota. The main thing this morning that throws up red flags is the cirrus cloud shield over much of the state. This isn't something that burns off during afternoon heating, but is rather persistent. This shield will act to limit instability this afternoon and could keep storms from firing until after dark or not at all. Dew points at the surface are a bit marginal this morning and it's not a sure thing that they'll recover this afternoon because of computer model issues lately. We won't get a true east wind for good low-level wind shear either, so that's another thing to throw in the bin of issues.


Nevertheless, we're going to drive up to south-central South Dakota (short drive) and wait there to see how things develop. Maybe Mother Nature will surprise us. The Storm Prediction Center has a Slight Risk area out for much of South Dakota, but that may be in jeopardy right now based on current conditions.

6/1 - 10am CDT - Moving South Today

We're ready for storms today after a long drive back south from Detroit Lakes, MN yesterday. We started the day in Oacoma, SD and are headed westward to catch a southern route near Murdo, SD. We expect to keep heading south through Nebraska until we see a good spot where winds and cloud formation become conducive for supercell development. That area could be as far south as Goodland, Kansas. West-southwest flow at 500 mb and moisture surging northward will create the instability needed for this afternoon, while east-southeast winds will contribute to the low-level shear necessary for rotating storms. The one issue we're dealing with this morning is cloud cover across much of Nebraska and portions of Kansas. It should burn off/move out in time for storm development, but if it doesn't we may have an "event failure" (AKA no storms). Check out the satellite image below and you'll see what I mean:


The Storm Prediction Center has issued a Slight Risk for severe weather this afternoon and tacked on a 5% tornado risk as well.


As we keep an eye to the sky this afternoon I'll be posting frequent updates on Twitter and Facebook. Be sure to follow me on those sites for the latest reports!

5/30 - 10:15am CDT - Time for Some Northern Plains Action

We're off to Eastern South Dakota (Northeast Nebraska maybe?) to intercept storms that will form up that way. This has so far been a difficult forecasting day because the computer forecast models show an area of low pressure in Nebraska this morning, but each have a slightly different scenario on where it ends up. Some are even forming a secondary low to the north this afternoon. The general rule for today is to drive to where the east winds are and adjust our position as necessary because we simply can't trust any model output. This is one of those days where skill in analyzing surface conditions and cloud formation will be key.


Since moisture, instability, and shear will all be ample today combined with the east winds, wherever they set up, the Storm Prediction Center has issued a Moderate Risk for severe weather with a 10% tornado risk. Supercells that form today won't stay isolated for very long since directional shear will be parallel to the cold front pushing through according to the SPC. If this happens as forecast, we may only have a short window to chase a good storm with a tornado risk, so being on-time is very important. That's why we left North Platte, NE at 8am his morning. We should be in our target area early this afternoon.


As we pulled in a restaurant to eat breakfast this morning, we saw The Weather Channel's Tornado Hunt vehicles in the parking lot. We also saw quite a few other chasers pull in to restaurants and hotels in North Platte last night, so I'm sure that town was happy to see the quick uptick in business generated by all the chasers.


Be sure to follow me on Twitter and Facebook today. I'll be posting frequent updates and photos from our chase, which should be a good one if the forecast plays out.

5/30 - 12am CDT - Upslope Storms Part Deux Fell Flat

Our second attempt in chasing upslope storms within a week fell flat today. Like last time, the cap stayed on too tight and a layer of clouds and fog overspread our target area just as we thought storms would initiate. While we waited this afternoon just east of Cheyenne, WY, we ran into Mike Bettes and the Weather Channel's Great Tornado Hunt crew.

The very fog that moved into our target area only grew thicker as we moved into Nebraska to try and limit our driving time needed for tomorrow. At it's thickest point, the fog dropped visibility to around 300 feet as we headed east on I-80. We literally could not see the signs on the side of the road until they were just to the right of the edge of our hood.

Tomorrow could be a pretty big day in the Dakotas and Northern Nebraska. The Storm Prediction Center has issued a Moderate Risk (45%) for portions of the area and expects a few significant tornadoes tomorrow afternoon before the storms merge into a linear line. I'll have an update tomorrow morning when we get on the road, which will be early so that we can get to our target on time.

5/27 - 10am MDT - Denver, Amarillo, Denver

The next 36 hours are going to be a whirlwind. We stayed in Denver last night after trying to chase an upslope storm setup in Eastern Colorado that didn't materialize thanks to cloud cover and possibly marginal southeast winds. We're now on our way to Amarillo to drop off our tour guests from tour 4 so they can leave on their flights tomorrow morning. We'll be leaving too... back to Denver again so that we can receive our new guests on tour 5 and begin another week of storm chasing. So, 8 hours to Amarillo today and 8 hours back to Denver tomorrow. We drove 414 miles yesterday in search of severe weather, and it's a shame that it didn't work out.


Next week's weather looks promising for chasing. Sunday will most likely be a day to setup for Monday's chase in the Eastern North Plains, but there's a chance something could fire in Nebraska while we're on our way. Monday already has a risk area outlined by the SPC in Nebraska, South Dakota, Iowa, Minnesota, and North Dakota. Tuesday will probably be a down day as a bit of a trough builds in. The rest of the week will most likely be a chase in the North Plains as well, but it's a bit too far away to make an accurate guess at where exactly we'll be. Looks like we may be lacking upper-level support in many areas after Tuesday, but we'll see how things shape up.

5/10 - 11:30am CDT - We Were Next to a Tornado Last Night!?

We're a little shocked and humbled this morning in South Dakota. Last night when we arrived at our hotel in Murdo, SD, veteran storm photographer Daniel Shaw rushed out to meet us saying he had to show us some photos. What he showed us was a set of pictures containing a rope tornado illuminated by lightning that was on the ground just yards from his position late last night. The tornado actually crossed the road 15 to 20 yards ahead of him and he was understandably shaken up. The kicker in all of this is that we were only a couple hundred yards behind Daniel when this happened near Philip, SD last night. He knew full well that we were right behind him based on our live updating position on the Spotter Network and that's why he came out to meet us. Our leader Todd and I remarked during the chase that we could see a wall cloud during the lightning flashes, but there was no sign of a tornado. We then stopped to get out of our van and were met with winds of 60 mph and higher from the west, which seemed very odd. The abrupt stop to that wind just seconds later added to the mystery. But we now have our answer... those winds were from the outer circulation of a tornado!


The strange thing in all of this is that the velocity couplet, or focus of rotation in the storm, was about three miles east of the road we were on, yet the tornado crossed the road heading the in the complete opposite direction, east to west, of the storm motion. Weird right? It seems there was a second updraft base with rotation that formed on the western edge of the storm and produced this tornado. There's also the possibility that it reached all the way down and over from the updraft base that was on the eastern half of the storm. This storm also wasn't terribly impressive on radar, meaning we we didn't think it would produce a tornado, but the ingredients were certainly there for a brief spin-up. We'll probably never know exactly how this happened, but it underscores the importance of staying vigilant even when you think you're in a safe position (we were based on radar) near a supercell.

We're traveling down to Kansas from South Dakota today in preparation for tomorrow's chase in Oklahoma or Southern Kansas. The Storm Prediction Center has a Moderate Risk (!) out for the region tomorrow and I think that's a good call based on the strong upper-level winds that are forecast to make their way through the area tomorrow. The storms that form will only move about 25 mph or less tomorrow, so chasing them will be relatively simple. Last year we chased two major High Risk outbreaks in Oklahoma and the supercells moved to the northeast at 55-65 mph, which made for a horrendously rushed chases.

5/9 - 10:30am CDT - On the Road to Valentine

We're on the road to our initial target location today, Valentine, Nebraska. Easterly winds caused by an area of low pressure centered just west and slightly south of this area are the focus of why we're heading there today.


Temperatures at 700mb are between 11 and 12C over a good chunk of Southern SD/Northern NE, so at least we'll have that on our side for tornado development. Moisture is still a bit short in the area, but some of the very latest short-range models indicate dew points reaching 65 and higher west of Sioux Falls, SD, which would be a very welcome development. Again, with a lack of upper-level windspeed the threat for tornadic supercells is iffy, but at least a couple of variables like surface winds and 700mb temperatures are in our favor. I'll be updating on Twitter and Facebook throughout the day!

5/9 - 8:30am - South Dakota Today... Maybe We'll See a Storm?

The overnight computer model runs have toned down the severe weather threat in South Dakota for this afternoon. While east winds at the surface and instability should be OK, the upper-level wind support that we need for supercells to form will be entering the region after the peak time for storm development. This is a problem because it limits our wind shear, much like yesterday. Moisture is another issue because dewpoints (green numbers on plots in left image) in South Dakota this morning are still in the 50's. Models are in disagreement as to whether they will actually recover into the mid 60's, but based on the performance we saw yesterday I'm inclined to think the models with lower dewpoints will be the more correct ones at the end of the day. With these issues, the SPC has issued a Slight Risk of severe storms for the western part of the state, but the 2% tornado risk runs through the eastern portion of the state as well:

Our target area will most likely be somewhere in the eastern two-thirds of the state south of Fort Pierre. We'll see what happens as we're driving along... I think we will see storms today but there's not a lot of evidence to support a good tornado risk. That's too bad after seeing the good potential for today on yesterday's model runs. Things always change, so surprises could be in store.

Be sure to follow me on Facebook and Twitter for the latest storm chasing photos and updates!

5/8 - 8:15pm CDT - Looking Forward to South Dakota Tomorrow!

Things just didn't materialize here in Nebraska today. A lack of good upper-level wind support and marginal southeasterly surface winds along with a strong cap suppressed severe storm development during the daytime hours across the region. We're going to settle into Norfolk, NE this evening to prepare for what could be a much better chasing scenario tomorrow in South Dakota. The Storm Prediction Center has a high-end 30% Slight Risk area posted for the western two-thirds of the state tomorrow. With a trough digging in further to the Plains tomorrow providing faster wind speeds aloft, I think tomorrow's outcome should be better.

5/7 - 4pm CDT- Hello From Amarillo, TX!

I'm all settled in here at our hotel in Amarillo after a flying in from Louisville. Tonight our tour guests on tour 2 will gather for orientation at a conference room here in the hotel and then we'll go out for a nice dinner before a week of gas station burritos and fast food while chasing.

As a tradition during each tour that departs from Amarillo, the restaurant we'll be eating at is the world-famous Big Texan Steak Ranch. This place is the real deal here in the Texas Panhandle if you're looking for a taste of the stereotypical "Wild West". At the center of the two-floor establishment is an elevated table where diners can try their hand at eating a 72oz steak (with side dishes) within an hour's time. Besides being the spotlight for all the diners at the restaurant, each participant's attempt at eating this behemoth is streamed live online via a video camera mounted on the second floor. It's a fun place and it certainly starts each tour with a lighthearted ice-breaker for everyone.

Tomorrow's target will be a spit decision. Our target area will most likely be somewhere near Wichita Falls, Texas, which is just a few hours drive from Amarillo, or Northern Nebraska (maybe Kansas?). The SPC has a Slight Risk for severe weather posted for West Oklahoma/North Central Texas and Northern Nebraska/Southern South Dakota, but we'll see how everything sets up in the morning before deciding on a specific target area.

The NAM model has a good setup for the Texas/Oklahoma border near Wichita Falls right now with high CAPEs, serviceable wind shear, and decent low-level moisture. The LCLs (Lifted Condensation Level - height of cloud bases) are a little high for my taste at 3000 to 6000ft, which could limit tornado potential in any supercell that fires up. The other chase target in Northern Nebraska/Southern South Dakota (or Northern Kansas based on some of the newest model output) seems to have most of the characteristics of the Texas/Oklahoma one, but LCLs will be slightly lower and shear values could be higher. Those two components alone lead credence to a higher tornado threat, but there's concern that moisture from Texas won't make it up there in time for the advertised severe weather development (see right image - 850mb dew points at 0z Monday). We'll see how it looks in the morning before a final judgement is made!

Be sure to keep up with my updates on Twitter and Facebook for all the latest information while we're chasing tomorrow!

5/24 - 10:30am CDT - Messy Setup in the North Plains

We're not terribly optimistic about today's severe weather setup in Nebraska, South Dakota, and North Dakota. The SPC has issued a Moderate Risk of severe weather today, but southerly flow at 500mb, fast storm motion, and ongoing thunderstorms in North Dakota will make today a difficult chase day. The southerly flow happened yesterday as well, which caused storms to become somewhat linear and move from south to north. Fast storm motion, on the order of 60 mph or more, means we won't be able to chase individual cells, but rather get in position to let them pass over us. CAPE values of 3000 J/kg, good moisture, and decent shear will sustain a severe threat, but it seems like the 15% tornado threat that the SPC is advertising won't be as great. We'll see how it goes today, but right now we're not expecting a very good setup this afternoon.

Don't forget to view our LIVE video stream at http://stormchasertv.com when storms form today. You can also follow me on Twitter and Facebook for the latest chase updates.

5/23 - 10am CDT - Kansas and Nebraska

We're heading north from Amarillo this morning to Kansas as we begin chasing this week on tour 4. During our break and switching out guests yesterday, a large wedge tornado touched down in northern South Dakota. It seems that tornadoes like to happen on our Saturday breaks, but we're looking forward to what the atmosphere has in store for us today.

There's a boundary right now situated from Southwest to Northeast across West Kansas and we're thinking that will play a crucial role in today's severe weather setup. Dew points to the west of this boundary are very low, while to the east they are high. At just 5,000 feet up, dew points are more uniform across the boundary. This means that the surface layer moisture has been scoured out to the west of the front, but the mid level moisture is still very much intact. A triple point low in Southwest Kansas will help to create east winds in Northwest Kansas today, but as it moves north we may find ourselves chasing in Nebraska. We'll see how things pan out. The computer models have been having a difficult time over the past 24 hours with the boundary in Kansas, especially when it comes to painting where the best instability will be and how things will fire up this afternoon. The Storm Prediction center has a Slight Risk for severe weather and a 5% tornado risk over West Kansas and Nebraska.

We'll be streaming LIVE video at http://stormchasertv.com today if severe storms initiate. You can also follow me on Twitter and Facebook for the latest updates from the road!

5/22 - 2pm CDT - Switching Out Tour Groups

Today is a day of rest in Amarillo as we say goodbye to the guests on Tour 3 and welcome our new guests on Tour 4 this evening. As usual we'll be having our orientation meeting tonight at the hotel and then going out to dinner at The Big Texan restaurant here in town. This past week will go down as one of the most exciting we've had out here because of our close tornado intercepts in Oklahoma on Wednesday. Media-wise it was very busy this week as well. I did a live phone interview on The Weather Channel on Wednesday and my video from our tornado intercepts aired on Thursday and Friday.

Will next week be as active as this week was? I think the answer is yes based on some of the latest computer modeling. Southwest flow aloft will continue throughout much of the High Plains next week, meaning shear and cold air aloft will be adequate for severe weather in parts of Nebraska, South Dakota, Kansas, and Colorado. That's quite a contrast from the last two weeks when we've been mostly in Texas and Oklahoma. I don't see any huge outbreaks in the near future, but I think tomorrow could be quite active in Kansas, Nebraska and South Dakota. The Storm Prediction Center has already placed the Nebraska/South Dakota border under a 30% Slight Risk area for severe weather, but they note that it could be nightfall before storms affect that area. We'll probably target an area south of where the 30% risk due to high cloud bases up there, which are not good for tornadoes. I'll have a full update tomorrow morning!