2011 American Weather Conference presentations

The first American Weather Conference was held at BWI this weekend. Though it was the first American Weather Conference, it was the 7th we have put on. The prior six were known as the “Eastern U.S. Weather Conference.”

The conference is both a gathering for people who love weather to hang out with each other, and a learning experience for many involved. Over the years we have been fortunate enough to consistently line up the top professionals in the business. This year was no exception.

Following a Friday of workshops by Wes Junker and Will Schwartz (that I unfortunately missed due to work), the main event of Saturday provided quite the show. Featured speakers (in order of appearance) included Bill Read, the director of the National Hurricane Center; Brian LaSorsa of NWS Baltimore/Washington; Brad Panovich of WCNC-TV; Mike Smith of WeatherData; and a conference regular, winter weather expert Paul Kocin.

Below are videos of the presentations. They are not close to fancy, and I originally shot in HD but lowered way down to cut upload time. As far as I can tell though, they work!

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Visible satellite loop of the May 24, 2011 “high risk” tornado outbreak in Kansas, Oklahoma and Texas

The amazing tornado year of 2011 rolls on. Today’s tornado outbreak, on the heels of a rare “high risk” from the Storm Prediction Center, has caused many more deaths and again seemingly impacted major cities, including the Dallas, Texas metropolitan area. Here’s an 8-hour visible satellite loop showing the outbreak’s evolution as seen from space.

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On the road in Kansas searching for tornadoes

We’ve departed Pratt, where we stayed last night. We’re currently on the road north — not quite sure where we are headed yet but we’ll probably try to position near the triple point for now and wait out the morning rain/storms in the area (mainly south and east, but we’re in the clouds and some rain will come through). Maybe not what you look for, but it’s early enough the atmosphere should recover, and some folks like Mike Smith have talked about tornadoes following morning rain.

I’m going to keep this short for now as things are somewhat up in the air, but generally on track for big storms and tornadoes later. I did a quick writeup for Capital Weather Gang this morning on the threat and chase as a whole. There has been some concern because the initial moderate risk from the Storm Prediction Center has been dropped back to a slight risk. However, much of their mod risk was hail related and the new tornado probabilities are not much different than before.

If a tornado touches down right next to me but I don’t see it… Did it really happen?

Classic hook echo tornadic storm near Philip, SD

We found our first tornado — sort of.

It was a frustrating day for many chasers in South Dakota, as “chaser convergence” in Murdo proved fruitless for most. We actually ended up traveling west early in the day to get some distance from the group that included Discovery’s “Storm Chasers”, led by Reed Timmer. I even got a snapshot of the Dominator vehicle driven in the show.

After a long day of waiting to the west of Murdo we were about to give up ourselves around 8:00 p.m. when we noticed towering cumulus quickly shooting skyward to the west. A new cluster of storms was forming right near Wall, South Dakota. Rather than eating dinner and heading back to the hotel (most chasers had already given up), we pressed on.

We were on the storm from the time it got going on the northern end of the Badlands through most of its life and all of its tornadic cycle. The journey took us down many backroads (read, dirt) of South Dakota, mainly in the pitch black landscape, only rarely dotted by a light or two from a farmhouse or nearby town.

Strong couplet passes by our location

As the storm developed, it quickly began to take on supercell characteristics and rapidly contorted itself into a hook echo, indicative of circulation. As the light dwindled we witnessed the storm congeal and an area of smoothed clouds develop near the rotation center on radar. This ultimately lowered a bit and we saw at least a rough wall cloud, if not a funnel cloud as well, in the dying light.

Once darkness hit, we traveled along the southeast side of the tornadic circulation for about 90 minutes. At one point (the image embedded here) we stopped and turned around as we got hit by strong inflow and heavy rain while a NWS meteorologist friend at home was letting us know he believed a tornado was on the ground, wrapped in rain, just to our north.

Another chaser who ended up on the storm did manage to get photos of the tornado. A meteorology student/chaser at Oklahoma who saw the photos said, “Most other chasers would’ve been where you were, but they didn’t want to battle the mud roads after dark, so they sat on the highway to watch the storm ‘move away’ and ended up lucking out.”

Here are a few iPhone radar grabs showing our location in relation to the storm as it developed, became severe warned, then tornado warned. Grab 1 | Grab 2 | Grab 3 | Grab 4 | Grab 5.

So, the chase was successful even if we did not personally witness the tornado. Out of dozens of chasers in the area we were the only ones on the storm the whole time. In this case, maybe we were “too good” at tracking it with the roped out tornado to the west of where you’d expect it on radar.

Now we’re on the road to Kansas in anticipation of tomorrow’s “main event” that has been on our forecasting radar for some time now. The Storm Prediction Center has issued a moderate risk, with tornadoes likely across the region. Some issues potentially remain, but this kind of setup often produces at least a mini tornado outbreak of 10-20+ touchdowns. More later, or tomorrow morning.,

Nebraska: First thought? It’s kind of chilly for storms.

Alma, NE — Well, it’s another state I’ve stayed in on this trip. Never been here before — nor have I been to a hunters convention (which was apparently going on across the street last night). I suppose it’s too late for the convention now, so back to thinking about storms.

The much anticipated trough is digging through the West Coast and sending little waves out ahead of it as moisture flows north from the Gulf of Mexico. Its path should bring increasing odds of severe weather this week. We may still end up with a quiet day or two, but it could be mostly on until we follow the final (and probably largest) system back east toward the end of the week.

Anyway, slight risk today: This was sort of a tough decision as the Storm Prediction Center was highlighting two areas of severe weather until the latest update this morning. One in Nebraska and South Dakota, and the other in Oklahoma and Texas. We ended up choosing the northern one because the atmospheric cap of warm air aloft is quite strong in the warm sector, and being nearer a front (the warm front) up here in the Nebraska area gives us better odds of not ending up watching thunderstorm producing clouds never materialize.

Additionally, if the southern storms do go up, the air mass is expected to be conducive to high based thunderstorms for the most part, and that region is further away from upper level energy (both the larger scale trough to the west and small spokes ahead of it). High base storms are not as likely to produce tornadoes because there is too much distance to the ground. The lighter winds don’t get the spin going as well. However, any cells that go down there should be massive.

So, it was a tricky call. We’ll see if it was the right one. Right now (9:00 a.m. local) it seems like it was. One major concern is moisture return into the area. As we arrived in southern Nebraska last night, dew points were still in the 30s (much too dry for tornadoes etc). There is also still some question as to whether convection will even initiate south of the warm front as warmer air aloft streams into the area as well.

Given the strong instability, warm front, dry line and low pressure formation, I would lean toward at least isolated storms — likely supercell in nature — forming somewhere in the region. If we’re lucky, we’ll find them.

It’s darkest before the dawn… More sun for now, but hope nearing on the horizon

5.5.11 0z GFS forecast for Tuesday evening with trough slowly progressing east.

Blackwell, OK – Things are somewhat precarious on the storm (or maybe sanity) front, with the promise of at least one chaseable system looming but still far enough out it’s no sure thing.

All along, the idea of a break after the first day (once that day was decided) was a real one. However, it appears that it will stretch longer than hoped and how the streak “breaks” is somewhat undecided. In any event, we’re chewing down days in wait mode.

So far, the traditional Tornado Alley and adjacent states have been largely quiet when it comes to tornadoes this season. While, as noted in a recent post, this is not terribly uncommon heading into May — when storms back into the region from the southeast U.S. – there are at least several large-scale players currently making an active environment more difficult to come by.

Two background issues are the, also previously mentioned, negative trend of the North Atlantic Oscillation and increasingly severe south-central U.S. drought. But, even in a pattern that is less favorable than optimal for severe weather in the Plains and Midwest, there are opportunities. Realistically, it now seems fairly apparent our actual chase days will be limited to only a few to a handful.

Over the next few days a large trough of low pressure in the upper atmosphere will build into the west and then move through the Rockies. As this happens, a series of surface low pressures should form on the lee-side (right side if you’re looking at a standard map) of the range, either remaining relatively stationary or moving northeast only to be replaced by another low pressure.

At the same time, an upper-level ridge of high pressure slowly progresses east through the period. These features will combine to replace the recently cooler than normal weather with hot and humid conditions streaming north. Our 70s are about to be replaced by 90s.

So, low pressure and humid conditions? Sounds good for storms, right? Maybe, and ultimately probably – for a time at least. As the upper trough is slow to progress east, conditions should become generally more favorable for severe weather, including tornadoes, heading into next week.

By Friday, traditional severe weather values – rising instability, moisture, convergence along a boundary (the dryline, then cold front) – will begin to show up in the southern Plains. Initially, it seems that too many ingredients may be stacked against storms to get many or any to fire up. It’s a process though; we have to start somewhere…

One issue, especially early on as the main trough only slowly kicks east, is that warm air is streaming in not only at the surface but aloft, so the atmosphere will tend to be “capped.” In other words, warm air has trouble rising into more warm air compared to when colder air is above and warmth wants to explode upward in the form of a thunderstorm.

Still, there have been many a severe weather outbreak with some initial capping, as it forces storms to go big or not happen at all. There have also been expected outbreaks that have been stifled by such an atmospheric condition because there was no atmospheric “trigger” like a cold front, dry line, and/or mesoscale boundaries like remnant outflow. The question to resolve is if/when the cap will break and where.

The typical dryline, created by dry/hot air coming off the Rockies and clashing with warm/moist air from the Gulf of Mexico, has been stifled for much of this year, likely thanks to much of the region being engulfed in drought. These grounds are typically much wetter than they are now, and evaporation from soil moisture adds fuel for storms in addition to what comes from the Gulf.

Storm Prediction Center severe storm outlook for Sunday-Monday (red) and Tuesday (green).

With the drought in place, even moist air traveling inland can be dried somewhat in the process. At the very least, it makes those looking for Plains storms wish for a southeasterly surface fetch more than usual.

The plan is to watch for the dryline to fire up (even in isolated fashion) prior to the trough ejecting out of the Rockies when a more general severe weather threat probably occurs during the early or middle part of next week.

The Storm Prediction Center has now outlooked the timeframe of Sunday-Tuesday in the extended, highlighting prime Tornado Alley chase territory

BY TUE/D6 INTO WED/D7…FLOW OVER THE PLAINS WILL BECOME
INCREASINGLY MERIDIONAL AS THE UPPER TROUGH BOTTOMS AND BEGINS
MOVING EWD. ALSO AT THIS TIME…A SUBTROPICAL JET IS EXPECTED TO
MOVE NWD AND PHASE WITH THE MAIN TROUGH…INCREASING UPPER LEVEL
WIND PROFILES. ALL THE WHILE…A DRYLINE WILL REMAIN ACROSS THE
CNTRL/SRN PLAINS WITH STRONG INSTABILITY AND AMPLE VEERING SHEAR
PROFILES FOR SUPERCELLS EACH DAY. TUE AND WED APPEAR TO HAVE A
GREATER TORNADO THREAT THAN ON SUN/MON WITH HIGHER THETA-E AIR AND
BETTER HODOGRAPHS. AN ISOLATED STRONG TORNADO MAY OCCUR…ESPECIALLY
ON TUE WHEN A STRONG NOCTURNAL LOW LEVEL JET RESPONSE IS FORECAST TO
OCCUR DURING THE EVENING.

We’re gathering ourselves for a day and hanging out locally in northern Oklahoma (visiting Wakita of Twister fame). Tomorrow we’ll head toward Oklahoma City, perhaps to visit some of the dot-govs. Saturday should begin to feature fairly strong to borderline extreme instability over parts of the region, so we’ll be on the lookout for activity along the dryline by then.

Sunday and beyond could be the real deal – trying not to get hopes up too much though! Sunshine is getting to my head… I may have more later on a few historical outbreak setups and how it compares to what we may see here into next week.

Leaving for “the storms” imminent: How do things look?

Before beginning: No, not everything here will be about weather! Just maybe most of it for the next few weeks…

The final countdown is on to the departure for two weeks of storm chasing. The plan is to leave Maryland around the crack of dawn on Sunday and head west (our South?) [Midday update: Leaving tonight it seems. Going to be a race to Arkansas area for storms tomorrow].

In the wake of one of the greatest and saddest tornado outbreaks in recent history that has become the deadliest since the Great Depression, it sort of makes me wonder exactly why I want to go storm chasing. Being that it was the second major tornado outbreak in a month full of tornadoes, it also makes me wonder if 2011 has already shown its best hand and will bluff from here out.

The pattern is changing up a bit, at least on certain levels. The past few weeks have seen a very positive North Atlantic Oscillation (NAO) which has been shown to correlate with increased activity over the Southeast U.S. When you add in remnant effects of a La Nina (also shown to produce tornado outbreaks in the Southeast), the tale of this month and the multiple cities hit is hopefully one not to be repeated anytime soon.

That said, tornadoes hit where they hit regardless of who is watching, and I still want some storms to follow around the empty spaces of the central U.S.!  Let me start the “analysis” by saying I’ve done more model watching in the day 8-16 range for this trip than I would ever do normally, as guidance in that range is a bit of a fantasy.

It’s been a roller coaster ride. Even at this late date I find myself vacillating in thought from “wow, we’re going to be busy” to “hey, it could be a cool story to tell about the quiet period of the record 2011 tornado season.”

There are some unknowns with this pattern changeup. If we go into a negative NAO, there should be a tendency for East Coast toughing, which could be somewhat problematic in that it keeps wavelengths short across the country and promotes at least temporary upstream or even West Coast ridging. So, at the very minimum, it seems the first week out there is not screaming “major” storm.

At the same time, the active jet stream partially behind all the severe weather this season appears to continue mostly unabated, with waves of storminess at varying strength and in varying positions every few days.  There could easily be at least one break of 2-3 days with little to no activity, but there is other stuff to do out there… I think.

There is potentially something of interest on the way out, especially if we went the southern route. The problem is that cooler air has invaded a good portion of the country following the last big storm — at least one shot of even cooler air is ahead as the negative NAO induced Greenland Block flexes its muscle.  It appears any severe weather would be fairly deep into the South and perhaps not that energetic, though it’s still evolving and models are keying in more heavily on this system now.

It’s likely that there would be at least some break after that initial system (perhaps a several day one?), though energy continually wants to spill into the northern Plains, and the models have had trouble with the strength of this energy for months now until the short range. However, it’s pretty early for activity up there, especially with the trough orientation fairly fast from northwest to southeast.  Hopefully the dryline will activate on quieter days, but the drought over Texas and growing north might complicate that.

The northwest flow, as modeled, could ultimately transition into a situation where convective systems form along it as warm air begins to advect back north heading toward or into next weekend. That could provide a more generalized storm risk each day, though the storms could be fast moving, and perhaps mainly non-tornadic in nature.

There are indications that by next weekend things could be more interesting in an “outbreak” sense. The question is if it’s still a fantasy or something real. The idea of more troughiness through the Rockies and into the Plains has been pushed back a little already, from near the 5-6th to the 7th-8th, but it’s been there on many runs.

On varying runs, this trough is modeled by the GFS to dig deep through the Rockies and spawn a surface low pressure somewhere near the Texas Panhandle into Kansas before strengthening and traversing east.  In a scenario like that, a significant tornado event would be possible.

Another potential scenario spit out is weaker, but consistent troughiness over the southwest and into the Rockies. This may allow for a regular feature of a weaker low pressure somewhere just east of the Rockies, which would at least promote the risk of storms through the period by drawing moisture in from the Gulf and creating instability plus some turn to the atmosphere.

The “no storm of consequence” scenario is a bridge we can cross if we get there. I’m cautiously optimistic, but perhaps slightly less so than a week ago. It could just be nerves…

Quick look at atmospheric conditions for a significant D.C. area tornado

A small composite mean sample of days with significant tornadoes in and around the Washington, D.C. area at various heights of the atmosphere is below. From low level (near surface — 850mb) to cloud  level (700 mb) and then into the mid-and-upper levels (500mb). These can be useful to compare a modeled setup to see if there is any extra risk of more than the garden variety activity.

Hopefully I’ll return to this in more depth as it’s something I’ve been meaning to do.

This post is part of a Washington, D.C. climatology series, both on and off site, that will be maintained at semi regular intervals.

Evening satellite loop of the April 27, 2011 tornado super outbreak

At least 141 tornado reports (as of 1:45 a.m. April 28), on top of 61 on the 26th. Many communities in Mississippi, Alabama, Tennessee and Georgia (maybe others still ongoing), including parts of large cities such as Tuscaloosa and Birmingham, have been devastated. This should go down as one of the largest tornado outbreaks on record, and solidify April 2011 as the month with the most tornadoes ever. There were even tornadoes confirmed around D.C., with more potentially on the way into the morning…

April 27, 2011

I’m going storm chasing!!

It’s been a wild severe weather season thus far, somewhat typical of a La Nina spring.

The plan is to depart Maryland somewhere between May 1 and May 6 (probably early end) with the ultimate destination the Central U.S. Note: I did not say “the Plains”, even though we’ll be there most of the time with any luck, since severe weather seems to have migrated east a bit over recent years.

Though the early concentration of events over the South, the Tennessee Valley and into the Carolinas is a fairly typical starting point for the season. This year has mainly been much more intense and active than usual. We saw similar throughout the winter, with multiple disturbances quickly flying along an active jet stream. While this should wane as Nina fully dies, it’s not likely to right away.

I will be headed on this ~7,000 mile journey with Jason Foster and Mark Ellinwood — the former a seasoned storm chaser and the latter a meteorologist and storm chaser. Jason is also known as “The Weather Warrior” and he contributes to Mark’s MADUSweather Web site. They recently intercepted tornadic supercells in the historic North Carolina outbreak of 2011 and are on a quest for the perfect mid-Atlantic tornado.

I am both eagerly anticipating the chase and also somewhat anxious, as the weather is unpredictable and we did “arbitrarily” choose a period to head out well in advance of knowing the evolving pattern — one that even of this writing is still fairly cloudy. Of course, arbitrarily choosing the best time of year for tornadoes (May has the most by the numbers, and May is prime-time in parts of Tornado Alley) is at least a well educated move.

My hope is to end up hitting a few good storm, with at least one productive chase day in the Oklahoma/Kansas/Nebraska area — prime Tornado Alley real estate. Though I am keeping expectations low (a nice rotating supercell and a great evening lightning storm would suffice), the goal of course is to see a twister if not more than one.

Being a photography buff, I already had plenty of gear ready to go. But, in the last month, I’ve been beefing up the collection to include an entry level HD video camera, a new mobile-friendly laptop, plus a ton of accessories and batteries.

We’ll be as wired up as possible, with multiple mobile internet accounts on different services. As long as there is a way to transmit, I will do my best to share imagery and video as quickly as possible either here, on Twitter, or via postings on the Capital Weather Gang. I also hope to return home with countless photos and video clips to properly document the journey in its entirety.

It should be a blast (as long as a high pressure ridge doesn’t park itself out over the area).  I’m starting to look over data to get an idea of what to expect. So far, the initial time-frame seems murky, and there may be a short break in the recent flurry of activity we’ve seen in what may be a record-breaking April of severe weather. Indications are it would be days rather than weeks, as the pattern reloads and probably shifts northwest with some broader-scale changes occurring during the period.

I’ll probably post some thoughts on chances/areas for early in the trip soon, plus I’m doing some general background research I might share if I have time, but for now feel free to peruse Mark’s recent thoughts here and here.