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!

5/23 - 11:50am CDT - Nebraska or Colorado?

Today we're in the Cornhusker state of Nebraska in search of severe storms. Yesterday's chase in what ended up being extreme southern South Dakota was short-lived as storms that formed up that way south of Murdo, SD quickly dissipated due to a low amount of moisture and contamination of their inflow via a layer of clouds that formed to the south of them. The storm we chased had a nice structure for a few minutes and even put down a bit of a wall cloud before it fell apart.

A cold front situated across the center of Nebraska will be the focus for storms this afternoon. The band of clouds on the satellite image is roughly where the front is located right now and it will slowly sag south and east today. A low forming over Eastern Colorado/Western Kansas should help back the winds out of the east this afternoon here in portions of Nebraska and that will increase low-level wind shear needed for rotating storms as that happens. This low will also create easterly winds in Northeast Colorado, so that may be a secondary target area for today.

We're already seeing some easterly winds beginning to set up in Nebraska this morning and we'll be watching where those develop this afternoon as well. Dew points are still quite low this morning in the upper 50's, but more moisture should move in this afternoon and bump up dew points to around 60 or higher. This is still a bit low for good storms, but we'll probably be better off than we were yesterday in this regard. Dew points in Northeast Colorado won't have to be as high for good storms thanks to the elevation there.

The environment today is rather "capped" as we say, meaning there's a warm layer of air above the surface layer that's prohibiting storm development. As surface heating gets going later this afternoon and into this evening there should be enough energy for updrafts to break through this cap and form storms. This means that storms should be fairly isolated at least starting out, which is a good thing since isolated storms are more organized, more likely to produce a tornado, and easier to chase. Some of these isolated storms may become supercells, and that's exactly the thing we're after since they may produce a few tornadoes today. Storms may condense into one or more lines of storms later this evening as the cap quickly erodes after dark. The Storm Prediction Center has a Slight Risk for severe weather today from Colorado to Minnesota and that includes a couple areas of 5% tornado risk. There's a chance we may bug out on our plans for Nebraska and move to the secondary area you see there in Northeast Colorado, so stay tuned.

Follow up-to-the-minute updates today on my Twitter and Facebook accounts!

5/16 - 10:45am CDT - To Colorado We Go!

After spending quite a bit of time in Texas over the past few days we are on our way north to Colorado this morning. We're going to try to chase some storms that may form in the upslope flow of the Front Range of the Rockies. Here's how these form: Moist air flows from east to west up the gentle slope of the mountains during the afternoon. This moist air when lifted by the terrain condenses because it's moving into cooler air aloft. As more air rises up this gentle east-west slope, it continues to condense to form clouds and eventually thunderstorms. Since the mountains act as a constant source of lift, these storms can be pretty reliable as long as other ingredients are in place.

Here's the issue for today though... Moisture is going to be hard to come by today because the last major system to roll through the Plains last week pushed all the moisture down toward the Gulf of Mexico. A little bit of it will be returning to the region today though and we can already see that happening on the current surface map. Dew points right now are in the 30's with a couple 40 degree plus readings across the eastern part of Colorado where these storms will form. In a perfect world you'd want easterly winds to be blowing in better moisture and to create better low-level shear, but this morning we're dealing with southeasterly winds. The good part is that it doesn't take as much moisture to generate these storms as it does in lower elevations. Generally you want dew points to be above 40 degrees in this region, and that's something we may struggle to get today if the computer models are correct.

Putting all of this together with some weak southwest winds at 500 mb (18,000 ft) there is a chance for some storms in Eastern Colorado today. With potentially weak moisture return the setup for anything severe looks very "iffy" at this point and the Storm Prediction Center has placed parts of Eastern Colorado under only a general thunderstorm risk because of this. We'll keep an eye on the surface observations this morning and afternoon to determine whether moisture will return as needed.

Last night I had a good internet connection at our hotel and was able to upload some video. Check out my footage of our encounter with golf ball size hail and flash flooding east of Lajitas, Texas on Monday:




Follow me on Twitter and Facebook for updates on our chase today!

5/15 - 11:30am CDT - Excitement in Southwest Texas Yesterday

My apologies for not having a blog post last night. We're in the Big Bend National Park area of Texas and there was little to no cellular data service where we stayed last night. Our travels along the Mexican border region of Southwest Texas yesterday were quite exciting though. We started off in Pecos, Texas and traveled south to Paradisio, Texas right on the border. We waited here for some storms to form before heading eastward to intercept them. Most of these storms were clustered together, but there were a couple cells that stayed independent that came toward us and crossed the border. The tornado threat wasn't realized yesterday because low-level shear did not play out as forecast due to unfavorable surface winds and multiple storms contaminating each other with cold outflow air. As we drove on the mountainous road along the Rio Grande river (yes there was a certain Duran Duran song of the same name stuck in my head) there was not much cell service so we had very limited radar updates. We drove east of Lajitas, Texas as the strongest cell at the time came at us rather quickly with no escape. Our vehicles pulled to the side of the road near a rock wall and that shielded us from the brunt of the golf ball size hail that came down.

This storm put down a huge amount of rain, so much so that the residents in this area that we talked to hadn't seen something like it in over four years. The deluge quickly overwhelmed the ground and widespread flash flooding took place. Our road east along the border was flooded by a foot of water at one point, so we stopped for an hour to let the water level drop. 6 or more inches of water is dangerous to drive through. The rushing rapids going over the road brought some pretty big rocks and debris, but luckily none of this was too big for a hand toss to the side of the road. Our group then continued on to a town just outside the Big Bend park area where we spent the night. I have some great video of the hail and flood yesterday that I'll try to upload once we get to a hotel with internet service.

Today's storm setup in Texas looks very marginal so we're touring the Big Bend area and then heading north so we can be ready for storms that may form in Eastern Colorado later on this week. With limited moisture in the Plains it might be hard to find some good storms over the next few days. We'll make the best of it!

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

5/13 - 11:35pm CDT - Switching Tour Groups and Heading West!

After a long drive from just south of San Antonio, TX to Oklahoma City we're looking back at what was a great Tour 1 on Storm Chasing Adventure Tours. Our trip this week took us 2,937 miles (4,726 km) through Oklahoma, Kansas, Texas, and New Mexico. We saw some great storms and I think everyone had a great time on our exciting chase!


Today was one of our "down days" in Oklahoma City when the guests from the previous storm chasing tour depart on their flights and the guests on our upcoming tour arrive. Tonight we welcomed our guests on Tour 2 and had our orientation before going out to dinner. Tomorrow we'll be on the move to Eastern New Mexico and West Texas to hopefully intercept some storms that will form on the upslope winds of the higher elevations down there. The Storm Prediction Center has a Slight Risk for severe weather down in that area, but our exact target location will be determined tomorrow morning based on the latest data.

My live storm chasing updates on Twitter and Facebook resume tomorrow!