5/21 - 11:55pm MDT - Nice LP Supercell Today

Today didn't turn out to be the best chase, but we made the best of it with the sighting of a nice low-precipitation (LP) supercell near Grande, New Mexico. This formed within a line of discrete storm cells that stretched from Southeast Colorado to Central New Mexico. The formation of these cells in a line among an environment characterized by northwest wind flow at 18,000 feet (500 mb) didn't make for the best conditions for severe storms, but a few of them did reach severe limits. Besides this low-profile supercell and possibly a couple others in the same line, an "out of the blue" classic supercell formed ahead of an eastward-advancing MCS (mesoscale convective system - line of storms) just west of Amarillo before being ingested by the actual MCS. It didn't form in the expected environment for this, so we were not in position to see this short-lived storm. More photos of the LP supercell we saw today are available on my Flickr and Facebook albums.

Our tentative plan for tomorrow is to head to the Valentine, Nebraska area to intercept a severe weather threat that may manifest up there as a large-scale trough begins affecting the Northern Plains. Many would consider this an "secondary" target area since higher dew points and better surface winds will be in North Dakota, but in this case the moisture up in North Dakota will likely be confined to an area closer to the surface since there will not be enough time for ample deep moisture to make it up that far north. Northern Nebraska should have some deeper moisture than North Dakota and even though less helicity (spinning motion in atmosphere) will be present in Nebraska, Energy Helicity Index values are still forecast to be elevated according to the Rapid Refresh model. We'll make a final determination based on data coming in tomorrow morning before heading out!

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

5/21 - 11am CDT - A Bit of a Surprise This Morning!

Yesterday evening we saw a wonderful view of the annular solar eclipse just south of Lubbock, Texas. This was my first solar eclipse and even though clouds obscured our view of the maximum "ring of fire" portion of the eclipse, it was a spectacular sight. It was good that we had an eclipse because the storm threat that we were targeting in that area was never realized. A good convergence boundary formed and intensified quite a bit, but it seems the "cap" (warm layer of air aloft) was too strong to get any good storms going. There was one small storm that formed to our east, but it quickly dissipated since it was moving into cooler air.

This morning we're waking up to some very good news. Last night's model runs, particularly of the Rapid Refresh, were quite pessimistic about today's setup in Northeast New Mexico and the western Texas Panhandle but early this morning things changed around considerably. The main difference here that I've noticed is the amount of moisture that will be available in this area. For example, the 4z run of the RAP model late last night had dew points near 50 degrees in Northeast New Mexico. The 13z run of the same run this morning has dew points from 60 to 65 degrees. That's a huge difference! Right now the dew points in the northeastern section of New Mexico are in the mid to upper 50's, so the newer runs of the RAP model with the increased moisture are looking good since higher dew points will move in this afternoon.

Having these higher dew points is so important because this moisture is pure thunderstorm fuel. Putting more moisture into the air near the surface increases instability because you have more latent heat contained in the  air as it rises. As such, the CAPE (instability) forecast on the RAP model has responded very positively to the model's higher "correction" in dew point this morning and we're looking at a situation where instability should be quite good at just under 3000 J/kg in most spots around Northeast New Mexico, parts of Southeast Colorado, and the western Texas Panhandle. This is pretty good!

Now that we've cleared moisture and instability for take-off on this event, let's go over what the winds will be doing. The change in the surface wind forecast between last night and this morning hasn't been as great as the change in dew point, but we're still seeing some differences. Winds today will mostly be out of the south-southeast or southeast in the region, with some places especially in Northeast New Mexico seeing a more easterly wind vector than what models were showing yesterday. Storms today will be forming in what we call upslope flow, so having more easterly winds blowing up the higher elevations in this region should create an ample source of lift. This should also increase wind shear a bit due to a contrast with the northwesterly winds aloft at 500 mb (18,000 ft) and create the potential for more organized, isolated storms. When you couple helicity, which is spinning in the atmosphere that takes wind shear to create, with the increased instability that we'll be seeing in a mathematical formula, you get an index called the Energy Helicity Index (EHI). I usually don't look at indexes and parameters too much since they get in the way of looking at the basics behind a storm setup, but EHI is one I do like because it's simple and gives you a decent idea where a tornado threat may set up since helicity and instability are so important. Values last night were slim to none on the models for EHI in our target region, but today with the increased moisture creating more instability we're seeing a marked upswing in forecast values to 2 or more in places.

Even though these values are higher than previously thought for today, we're still not looking at any sort of severe weather or tornado outbreak here. What we are seeing is increased potential for an isolated, organized chance for severe weather in this region that may carry a bit of a tornado threat with it. Right now we're monitoring current conditions across the area and picking out where storm formation may first occur. We drove through some storms this morning on our way from Lubbock to Amarillo as you see on radar there to the right, but those are clearing and the majority of the western Texas Panhandle and Northeast New Mexico is now clear from the rain. A pretty shallow cloud deck is hanging around in Northeast New Mexico at the moment, but there should be time to burn that off and create instability from the heating of the day this afternoon.

Taking all of these factors into account, the Storm Prediction Center has issued a Slight Risk for severe weather in portions of New Mexico, Colorado, Texas, and even the extreme western Oklahoma Panhandle. The Slight Risk includes a 2% tornado risk due to the increased shear and instability that's expected this afternoon that could create some supercell storms. I'm not a big fan of the northwesterly winds aloft at 18,000 feet today because you generally want southwesterly winds up there to bring in drier air aloft and enhance wind shear a little bit more, but this will have to do today. We've seen decent storms with this kind of upper-level wind situation before so it's not enough to rule anything out. It's nice to be able to chase on a day when we thought we would not be able to, so anything we see today will be icing on that cake!

Follow my updates today on Twitter and Facebook for the latest.

5/13 - 10:15am CDT - Going West!

This week's storm chasing tour is starting out with a trip west from Oklahoma City. Fast westerly and north westerly winds aloft this afternoon over West Texas and Eastern New Mexico will provide support for potentially severe storms. While originally it looked like we would definitely be chasing in an area near and west of Fort Stockton, TX, the latest data coming in right now has actually increased the amont of moisture closer to Amarillo and Lubbock, TX. This moisture along with easterly winds rotating around a high pressure center near Wichita, KS could provide a secondary target area for us, which is good because we may not have to drive as far today! We're keeping an eye on the trends as we're traveling west on I-40 and right now we're leaning toward the more northern target near Amarillo and Lubbock because we think the models are underestimating the amount of moisture that will be allowed into that region this afternoon.

The satellite picture has been on our computer screens this morning too because it's revealing where storms may set up later on today. The previously more favorable target near Fort Stockton in far West Texas on I-10 looks a bit dismal at the moment because of the showers and clouds currently over that area. This may act to inhibit surface heating and the building of instability this afternoon for storm development. There are some storms in Eastern New Mexico, but those may actually help to moisten up the atmosphere closer to where you see the favorable clear slot in the clouds near Amarillo and Lubbock.

The Storm Prediction Center has a Slight Risk area for severe weather over extreme West Texas and the eastern half of New Mexico for this afternoon. This outlook came out before the latest data showing the favorability in conditions near Amarillo and Lubbock did, so some northward changes may be made in the outlook that will come out at 11:30am CDT. Overall, the (small) tornado threat today highly depends on how much moisture we can get into the area so that cloud bases are low enough along with how much low-level shear sets up.

Follow me on Twitter and Facebook today for live updates!

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!

5/11 - 11am CDT - A Crazy Chase in South Texas Yesterday

Our timing yesterday was just about perfect. As we surged southward from Carlsbad, New Mexico to the Del Rio, Texas area we began tracking storms that were forming in the mountains of Mexico near the Texas border. One fairly supercell formed along a boundary of converging wind just north of Laredo, TX in Mexico and we knew that this was the storm we needed to chase. It merged with another supercell that was moving north quickly to create a big storm with some intense rotation. We were able to get to the south side (where a tornado would be) just in time so that the hail and intense rain wouldn't cut us off from our road down to that area. Once we were there we saw some definite rotation and a couple wall clouds, but the storm was moving fast so we had to keep moving toward Laredo. We pulled over in a parking area just north of the city and continued to watch a wall cloud form that had a tiny hint of a funnel cloud in it. It was so small that it was barely visible, but it was certainly in rotation and was on the correct part of the storm. That was about all the storm had to offer tornado-wise.

By the time we made it east from Laredo the storm had merged with others to form a line of storms called an MCS (mesoscale convective system). This pretty much killed the tornado risk for this storm so we watched a very impressive lightning show from it as the sun set. Given the excitement that we had while chasing the storm while north of Laredo yesterday, it was a pretty good day! You can find more storm chasing photos from yesterday and earlier this week on my Flickr and Facebook albums.

Today we're traveling back to Oklahoma City so that our guests on Tour 1 can depart on their flights tomorrow. Tour 2 starts tomorrow night with our orientation and then we set out on Sunday for another week of storm chasing!

Follow me on Twitter and Facebook anytime for storm chasing updates.

5/9 - 11:15pm MDT - Another Day in New Mexico

My apologies for not having a blog post this morning. There is no wireless data coverage here in Southeastern New Mexico for my iPad and therefore when I hit the "send" button on this morning's post, nothing happened! Today we traveled to Carlsbad, New Mexico, where we met up with a film crew from the Travel Channel. This crew is taping a show about "extreme tours" for the network and I'll have details on when the show will air as I get them.

Tomorrow we'll be heading to Carlsbad Caverns just up the road here and then on to Roswell for more sightseeing in this fabulous part of the country since prospects for storms tomorrow don't look good. There is a Slight Risk for storms in South Texas tomorrow, much like yesterday, but the forecast points toward more of an MCS-style storm scenario than a supercell one. Even if supercells do form down there, it's a very quick trip from where they'll be in Mexico (where we can't chase) through Texas to the Gulf of Mexico (where we can't chase for even more obvious reasons). So... We'll stay around here in Southeastern New Mexico where the mountains and ample moisture will provide storm chances for us tomorrow as we tour around the region. These won't be terribly severe, if at all, but this is probably our best chance to see storms given the lack of moisture around the Plains right now. Doesn't look like this pattern will break for the rest of the week unfortunately. As we head toward next week we're hopeful that things will change for the better.

Follow my updates on Twitter and Facebook throughout my chase!

5/8 - 12:10pm CDT - Targeting New Mexico Today

We're on the road west today from Fort Stockton, Texas as we move toward Southern New Mexico. This is one of two areas we considered chasing in this morning, with the other being in Southern Texas. The reason we are not in Southern Texas is because there are thunderstorms going on already down there and the cool air and cloud cover from those will act to contaminate the environment for storm development this afternoon. Even though the very same cold front we saw yesterday and the day before will act as a focus for storms down there today, this contamination should rule out most of the chance for nice, isolated supercells.

Even though 500 mb (18,000 foot) winds will be stronger in Texas because a shortwave disturbance on the edge of an upper-level low is moving through the region, they should be ample in New Mexico. The southwesterly flow at that level and the fact that winds will be spreading apart (diverging) should lead to rising air in this region near the surface. These winds coupled with easterly surface winds will create wind shear, which is needed to sustain and cause a storm to rotate.

The Storm Prediction Center has issued two Slight Risk areas for today in Texas and New Mexico. There is a 2% tornado risk in Southern Texas, but this may not play out well down there thanks to the ongoing storms and clouds this morning. There's no tornado risk area in New Mexico, but my hunch is that there might be the potential for one or two little ones there today based on the directional shear that will be present with even a little bit of speed shear. Moisture will be a bit limited today, but you don't need as much in the upslope areas of New Mexico because elevation compensates for a lack of moisture. We're keeping an eye on conditions as they develop and hopefully I'll have more great pictures to share later today!

My constant updates on Twitter and Facebook will continue today during our chase.

12/17 - 11:50pm - A Not So White Christmas

Positive NAO - http://www.ldeo.columbia.edu/NAO

Christmas is just a week away and snow chances for many in the eastern half of the nation look pretty bleak. The next major system to pull through on Tuesday and Wednesday will produce snow in the Plains, but to the east it's expected to be all rain. A second low moving through the Deep South on Friday will bring more rain, but most of that will stay south of Kentucky and the heaviest south of Tennessee. After that point it looks pretty dry right through Christmas. Why so rainy and relatively warm lately? It has to do with the North Atlantic Oscillation, or NAO for short. When the NAO is negative, storms tend to ride up the East Coast or just west of the Appalachian Mountains. This is a recipe for snow for many across the East since these storms have cold air streaming in just to the north of their track. When the NAO is positive, storms begin deflecting northward to Canada before they reach the Mississippi River. This means that the cold air and snow with these storms stays out in the Plains. The NAO is in this positive phase right now and isn't forecast to go neutral or even negative until around the new year (see forecast and history chart to the right). Until we can get the NAO negative, I wouldn't bet on a winter storm for Kentucky, Tennessee, or much of anywhere else in the East.

23% of the United States is covered by snow at the moment, which is quite a bit lower than the 47.3% covered by snow at this time last year. Aside from Lake Effect snowcover in Pennsylvania and New York and snowcover in northern Maine, the East is snow-less.

A big winter storm is forecast to hit New Mexico, the Texas/Oklahoma Panhandles, and Kansas on Monday and Tuesday as an area of low pressure cuts northeastward (because of the positive NAO as explained above) through the Plains. A Blizzard Warning (green color on right image) has been issued for Northeast New Mexico while the other areas are under a Winter Storm Watch. Areas in the core of the snowfall north of Amarillo, TX up through Dodge City, KS could get well over a foot of snow.

5/16 - 12:45pm MDT - Touring New Mexico

We just toured Carlsbad Caverns in New Mexico and are getting ready to hike around the Guadalupe Mountains near the Texas/New Mexico border. It looks like this will be our last day of "touristy" things as the risk for severe weather increases tomorrow. While it won't be a big risk tomorrow, some moisture will be streaming back into the Southern Plains and we may chase a few elevated thunderstorms that form in the evening. Of course the bigger risk is still Wednesday, Thursday, and Friday, so we'll continue to monitor that. The return of moisture into the region may be better than previously thought, so this could be a good end to the week! I'll have a more detailed discussion on that setup tonight once some new computer model runs come in. Check out this panoramic photo I shot of the view from Carlsbad Caverns today:

5/15 - 6pm MDT - New Mexico!

Storm Chasing Adventure Tours is in Carlsbad, New Mexico for the evening as we're still waiting for the severe weather threat to ramp up during the middle part of the week. We visited Roswell, New Mexico this afternoon and the associated alien museums and gift shops before heading to Carlsbad where we'll view the bats flying out of Carlsbad Caverns this evening near sunset.

12z GFS dewpoints at 7pm CDT Wed

Tomorrow should be another "touristy" day before we begin seriously looking at the risk for a severe weather event across much of Texas and Oklahoma on Wednesday, Thursday, and Friday. The latest models have moisture streaming back into the region nicely, but we're keeping a close eye on it. You can see the dewpoints rising near the Oklahoma/Texas border on the right-hand image from the GFS model. Should moisture return as advertised, things should shape up nicely for mid to late week. Three or more good days of chasing in a row? That sounds good to me!

5/16 - 10:45pm MDT - Not Much Happening in New Mexico

It seems that a layer of warm, moist air at the mid levels of the atmosphere kept things pretty tame here in New Mexico today. Storms tried to get going, but developing updrafts would hit that warm layer and simply come to a halt, spreading outward instead of upward. A few thunderstorms eventually formed near sunset, but they were very weak and didn't have a snowball's chance on Mercury of producing a tornado. Basically, we had most of the elements (shear, warm surface layer, etc), but the air in the mid levels just would not allow things to go.

We'll be touring Carlsbad Caverns tomorrow morning before we set out for tomorrow's chase in the afternoon. It looks like we'll be chasing south of Lubbock, TX again as an area of low pressure in Mexico moves northward and brings southeasterly winds to West Texas. A cold front associated with a low in the Ohio Valley will also translate southward through most of Texas tomorrow, which may provide some lift. Even though instability looks good, shear and EHI values aren't looking great on the 0z NAM computer model. The SPC has issued a Slight risk for severe weather tomorrow south of Amarillo, but I'll hold off on making judgment on tomorrow's chase until the morning. A lot can happen overnight as computer models and surface conditions change. Let's just hope the storms actually form tomorrow! 

5/16 - 10:30am CDT - SE New Mexico

We're on our way to the southeast corner of New Mexico to see what kind of storms develop down there this afternoon. We're not terribly optimistic about today's setup because of weak surface winds and an ongoing MCS (mesoscale convective system - line of storms) this morning on the Texas/Mexico border. Redeeming qualities of today's setup are good instability, decent shear, and ample moisture. The increased elevation should provide a little bit of lift out there, but we're not seeing the push of dry air from the west that we need. In any case, we'll see how it goes today.

We'll be streaming LIVE video at http://stormchasertv.com if storms form today. You can follow me on Twitter and Facebook as well to get the latest updates on our chase and video streaming.