perilous planet

All new blog! Please update your links.

2009-08-28T11:22:00.003-06:00

I've completely rebuilt my blog and moved it to a new address:

Perilous Planet Blog

My old blog will remain as an archive for a little while, but all new posts will occur at the above link. For those of you who have links to my blog, please update your links now - thanks and enjoy!

Rockfall mitigation work yesterday, back in Boulder tonight.

2009-08-09T21:57:00.002-06:00

I spent yesterday afternoon shooting rockfall mitigation at 8000 feet on the Montana - Wyoming border. Hanging out of a car window with a thousand foot drop below me would normally be fun, but not so much when I'm sick. Hoping to shake this head cold soon. Looks like I got a few good shots but if I didn't, no one will have to twist my arm to get me back to Montana. And for the record, the best bagel in the world is at Coffee Factory Roasters in Red Lodge - wow.

Back in Boulder now after coring a thunderstorm on the way home. Saw some amazing storm structure at sunset. About a thousand frames from the last four days are awaiting the editing process, and they'll continue to wait for another night - I need some sleep.

Amazing lightning yesterday, two tornadoes today, more tomorrow.

2009-08-06T22:41:00.011-06:00

Wednesday night's slow moving thunderstorms over the Northern Rockies gave me some of the best lightning shots I've ever captured. I was so excited I couldn't sleep last night! Trail running down a hillside in the dark with heavy equipment probably didn't help either. This photo is just a taste - I'll add a better one to my portfolio later next week.

A sleepy drive into southern Montana today put me right into position for a great show. Two small and short-lived tornadoes on the same storm east of the city of Billings. Reasonably photogenic, but nothing to lose sleep over tonight!

Tomorrow looks to be another great day with supercells in southeastern Montana. Could be a full day of severe weather actually. For now, it's goodnight from Red Lodge - I need a lot of sleep.

Severe thunderstorms along the Front Range last night.

2009-07-21T19:30:00.002-06:00

After an unsuccessful night of shooting lightning, I spent the morning touring the damage path of the severe storms that swept through the Denver area last night. Lots of small- to moderate-size hail damage, such as defoliated trees. There were also many tree limbs broken and a few large trees knocked over. In some cases, limbs crashed onto powerlines, which eventually caused a power outage for tens of thousands of people. At one point, a tornado warning was issued for a small area west of Denver. However, there is no evidence that a tornado actually formed, and the few reports that were made were vague and unconfirmed (a common problem with night time tornadoes). All of the damage evidence strongly points to severe downdraft winds near the leading edge of the storm, which had a Doppler reflectivity value of 70 dbz for several minutes. This is readily evident in the flattened tops of standing trees, as well as the downstream orientation of the debris within the damage path. Based on my experience in disaster areas, I'm estimating downdraft (or "downburst") wind speeds up to 85 mph. The National Weather Service is also reporting that the damage was caused by downdraft winds. In any case, it was an eventful evening that developed rapidly and left behind some nice cool air in the middle of a hot July week.

Successful couple weeks of severe weather shooting.

2009-06-27T21:20:00.002-06:00

Nine days and three thousand miles later, I managed to capture some essential imagery for a severe weather project. Covering Colorado, Nebraska, Kansas, Iowa, and Missouri, this is the largest project I've worked on yet. The photography covers a diverse set of atmospheric hazards, from tornadoes to flooding. I still need a couple more events in the Great Plains to complete the project. Hopefully, some July and August weather will yield something photogenic. In the meantime, I'm finishing up editing, gear maintenance, and a little writing as well. Additionally, I hope to have a couple new shots added to my portfolio in the next couple days.

An Unlikely Weapon, the story of Eddie Adams and his amazing photojournalism, opens this Thursday (July 2nd) at the Starz Film Center. I'll be attending at least one showing this week - hope to see some other Denver photojournalists there.

Another Colorado chase: several funnels, hail, and possibly one brief landspout tornado.

2009-06-10T20:12:00.007-06:00

Once again, Weld County magic set up in my front yard and it was an easy catch with storms only moving at 10mph. Found some small hail, very heavy rain (which produced some flooding in Fort Collins), and several funnel clouds. This storm tried for hours to produce a tornado and I was right under it the entire time. A trained weather spotter called the National Weather Service to report a tornado, which there definitely was not at the time because I would have been in it! I would like to see our Spotter Network be more careful in what they call a tornado as this was definitely a false alarm. However, about 30 minutes later, I noticed some dust spinning up in a field just one mile from my location. Sure enough, a small landspout (non-supercell) tornado was trying to form. I noticed a small funnel at cloud base just above the spinning dust, and the dust had rotation and lifted rapidly. However, I never saw a fully condensed funnel so I'm hesitant to call it a tornado. In any case, it only lasted about 45 seconds and did no damage in this very rural area near Keensburg, Colorado. So, almost got my hat-trick, maybe I did, who knows. This photo is of two funnel clouds, which at first I thought were just "scud", but they both showed slight rotation and were firmly connected to the cloud base.

Street flooding, large hail, and another tornado makes for another $5.00 chase day in Colorado!

2009-06-09T20:20:00.006-06:00

After getting drenched in torrential rain at my house in Boulder, I decided to head northeast to get in front of the developing late afternoon storms. Again, my primary goal was just to take all the gear through another test run but once again, Mother Nature produced quite a show. Southern Weld County was covered in hail, with many stones around one inch in diameter (one chaser reported hail up to two inches). Two cells merged into one large cell, a process which generated just enough shear to get things spinning (looking at the initial cloud structure and surface observations, shear seemed minimal today so I wasn't really planning a serious chase). Several funnels were reported, prompting tornado warnings. I stayed with the cell long enough to catch a view of one of the funnels. From my low contrast perspective, I could just barely see the funnel stretch and appear to make brief contact with the ground. This was later confirmed by one of the Denver Channel 7 storm chasers and thankfully, no damage or injuries were reported. No photos of the tornado this time because it was too small, poorly lit, and I was just a little too far away. I did get some nice shots of the updrafts thanks to a scoured atmosphere and a very defined rear storm line. Otherwise, I would call this a bust in the absence of good photos that I can use for any of my projects.

That being said, I only spent about $5.00 on this chase. Plus the water and soap to scrub the Weld County mud off the vehicle. So that's a total of $10 for two tornadoes this week. The cheap chasing is coming to an end however. Central Plains chasing begins soon and after these local chases, I think everything is ready. I'm now running signal enhanced mobile broadband in my chase vehicle, along with a couple portable surface weather instruments, GPS, and enough camera mounts to keep any photojournalist happy.

Chased a small tornado across the Denver area today.

2009-06-07T20:55:00.004-06:00

Today was another day of vehicle and equipment testing, and I was going to chase just about any cloud as a dry run. Thankfully, plenty of mountain-induced shear kicked in and gave me a real tornadic storm to chase. The first tornado was born about 20 miles east of my house and I stayed with it for a few minutes, although I only ever saw the funnel without ground contact. Farther to the southeast, I caught up with an EF0 (maybe EF1) tornado that caused some light damage in Aurora. It was never very photogenic, mostly because of all the moisture, except when Brittany McKown nailed her photo that is currently posted on the Denver Channel 7 website - indeed, one of the best funnel cloud shots I have ever seen! I was able to catch a couple shots of a very thin tube / rope tornado. These are being reserved for other interested parties, so I am unable to post them at the moment. Media outlets are reporting a total of five tornadoes, and I suspect this number is very close to being correct, with one parent storm possibly responsible for all of them.

In all, a mostly successful chase with only my memory of the Denver road network and NOAA weather radio to guide me. Tonight, I finished installing GPS, retuned the com antennas, and serviced out the vehicle for field work later this week. Getting excited now!

Worked out the forecasting mothballs today with a decent severe storm in Northern Colorado.

2009-06-04T21:44:00.006-06:00

I had almost written off the severe storm potential today because I had to teach until late afternoon. My initial forecast was for severe thunderstorms north of the city of Limon because surface heating was ongoing in the morning, while the western urban corridor was locked under stratus. Indeed, the most severe storm of the day crept southeast across the Wyoming border toward Fort Morgan early this evening. Beautiful structure and golf ball sized hail kept it severe warned for at least half an hour. After watching the earlier storms to the south on the Palmer Divide fizzle, I stuck to my forecast and stayed north. Sometimes, the most basic meteorological (and climatological) parameters are the ones to pay attention to on chase day. Hopefully, I can pull another rabbit out of my hat as I head northeast into western Nebraska tomorrow, and probably again on Saturday.

EDIT: Michael Carlson actually got some great shots of the southern storms on the Palmer Divide - click on his name to the left to see them.

All new NaturalHazards.org is now online!

2009-05-09T20:11:00.002-06:00

In 1998, I developed the first comprehensive website devoted to natural hazards. This site has been visited by over half of a million people from more than 75 countries, and is a primary reference for several major publications, such as Encyclopedia Britannica Online. That all sounds great, but the site was becoming quite dated and in desperate need of new content. I've spent the last couple weeks re-designing the site to make it more accessible and more visual. Although it still has some growing to do, the incorporation of high quality imagery and updated text content has given it at least a breath of life. Unfortunately, with my field season only one week away, most of my time will now be devoted to other projects. However, I am going to make a serious effort to constantly produce new content for the site as a byproduct of my work for these other projects. If you get a chance, take a look: http://naturalhazards.org. Of course, I welcome any and all feedback.

Snowstorm over, Boulder melting rapidly.

2009-04-18T11:41:00.002-06:00

Our Spring snowstorm turned out to be mostly a dud in Boulder and Denver, at least as far as snow accumulation. Boulder received half a foot of wet snow for the entire storm. At elevations above 7000 feet, several feet of snow were recorded in some areas! Sporadic power outages have been occurred throughout the area due to heavy snow snapping tree limbs, which then fall onto powerlines. Boulder probably ended up with over an inch of rain equivalent moisture, and this should help alleviate the moderate drought we've been in for several months.

The National Weather Service is calling for additional accumulations this afternoon in Boulder, but that won't happen as temperatures are in the low 40's and only light rain is falling. From here on out, it's all Spring. Temperatures should reach 70 degrees later this week.

No additional snow accumulation today, but photos possible tomorrow.

2009-04-17T11:26:00.006-06:00

With the surface temperature stuck at 35 degrees and only light wet snow falling, there will be no additional accumulation of snow in the Boulder area today. This includes grassy areas, not just paved surfaces. The National Weather Service's estimation of 8-12 inches for the daytime in Boulder is much too high. Upslope, above 7000 feet, some snow will continue to accumulate. Verne Carlson is reporting fourteen inches already up in Coal Creek Canyon!

As temperatures drop slightly tonight, I expect to see significant accumulation in Boulder between the hours of 8:00pm and 6:00am. Saturday's daytime temperatures might turn out to be too high to allow for any additional accumulation after the early morning hours. As I feared, slightly higher temperatures have turned this storm into a higher elevation storm. Boulder, Denver, and most of the urban corridor are thankfully receiving much needed moisture from this event, but little snow accumulation. This was a tough storm to call and the National Weather Service did a pretty good job, other than not updating their accumulation totals when necessitated by warm surface temperatures.

Heavy snow falling, but late to start and accumulate.

2009-04-17T08:55:00.004-06:00

Our Spring snowstorm has finally materialized, but many hours late, as I predicted. Yesterday, light rain and a couple gropple storms covered much of the Boulder area. The rain did not turn to snow until about 6:00 this morning and this will reduce our snowfall totals. The very wet snow is also having trouble accumulating on the warm ground and has only reached about 1.5 inches in the last three hours on grassy areas. Roads are slushy, but not snow covered and not really slippery yet.

Last night, the National Weather Service reported snow falling in the foothills, accumulating to 2-9 inches. There was nothing on radar to indicate this, and I spoke with a couple friends (who live above 7000 feet) who said only light rain was falling. Perhaps one of the smaller valleys at higher altitudes was receiving snow, but this was certainly not representative of the Front Range foothills. In any case, the latest NWS forecast is still calling for up to two feet of snow for Boulder by Saturday evening. I think this will eventually turn out to be a significant snowstorm, but with a surface temperature just over 35 degrees, so far it's just slushfest '09. I think it's safe to say that NWS has over-estimated snowfall totals for this storm. I'll probaby start shooting this afternoon and I'll try to post some shots then.

Big snow on the way for the Boulder area.

2009-04-15T21:40:00.003-06:00

Spring, which we had back in January, has left and been replaced with bi-monthly snowstorms. The GFS model is currently showing one inch of water in the atmosphere on Friday, which should be enough to give us ten to twelve inches of snow in Boulder by the end of the event on Saturday evening. The National Weather Service is indicating up to twenty inches of snow, but this is unlikely as Thursday evening's rain will probably not turn to snow as quickly as expected. I'm mostly basing this on climatological forecasting (it is mid-April, after all). The Denver area will likely see less snow than Boulder, as upslope forcing is more critically local for this event. In any case, this will be heavy, wet snow.

As I mentioned in my meteorology class today, this has been a tough storm to forecast. A slight shift of the low pressure center, or the advection of slightly warmer temperatures, will drastically decrease snowfall totals. Our forecasting ability, in this case, is limited not by model uncertainty or a lack of understanding of the atmospheric mechanisms, but more so by the chaotic nature of the atmosphere itself. Small changes close to the time of the event can result in large changes in precipitation for cities where orographic lifting is the primary lifting mechanism. In other words, welcome to life on the side of a mountain range.

More posts and photos to come on Friday.

Weekend of snow comes to an end.

2009-04-05T12:08:00.007-06:00

A long weekend of heavy snow and blizzard conditions is finally tapering off. Several counties are still under winter weather advisories, but the low pressure cell that generated the snow has departed to the east. Snow fall totals in Boulder County ranged from five inches to eleven inches - a highly variable storm. No big wind here, but eastern Colorado has seen gusts over 50mph, leading to blizzard conditions. The city of Fort Collins had a power outage that affected 7000 people. The northern portion of Interstate 25 in Colorado and the eastern portion of I70 in Colorado were both closed yesterday, but reopened this morning.

This is the Foothills near the Flatirons Rock Formation in western Boulder.

Heavy snow in Boulder at 11:00pm.

2009-04-03T23:13:00.002-06:00

Under a Winter Storm Warning, our light rain just turned to heavy snow at 11:00pm in Boulder. A Blizzard Warning is in effect for the eastern plains of Colorado, where winds could gust up to 50mph. Boulder will probably get a foot before the snow finally comes to end Saturday evening / Sunday morning. Should be good for a few shots, and I'll try to post some tomorrow.

(pseudo) Four Corners Low, Take Two!

2009-04-02T09:34:00.004-06:00

Since a couple days ago, the GFS model has indicated another psuedo- Four Corners Low pressure cell smacking into Colorado in a nearly identical performance to the storm we had a week ago. This one is originating a little farther north, but the outcome will be very similar otherwise. Confidence is high and it looks like Saturday will be another 1-2 foot snowfall event along the Foothills of the Front Range. Like last week, snowfall rates could exceed 2 inches per hour and blizzard conditions are likely for much of eastern Colorado. I'll be chasing around the Metro area and will keep my blog updated with data and photos.

Boulder digging out, on the move after 16 inches of snow.

2009-03-27T10:06:00.002-06:00

Boulder is digging out and back on the move after yesterday's significant snowstorm, and our only real snowstorm of this Winter. Streets are still snowpacked and icy, and digging out a car requires about half an hour (or more) of work. Although we didn't get near the 24 inches I was imagining (hoping?) yesterday morning, Boulder still ended up with just over 16 inches of snow. I've heard reports of near 20 inches a little higher up the slope, but I haven't verified it.

The snow continued falling until just before dawn. The Flatirons are a winter wonderland this morning and a reminder to all why we live in this beautiful place.

Snow still coming down, Boulder approaching 15 inches at 6:00pm.

2009-03-26T17:58:00.004-06:00

Snowfall rates have dropped dramatically, but the snow won't stop entirely until after midnight. South Boulder currently has just under 15 inches of snow. Curiously, the National Weather Service actually downgraded their total daytime accumulation. The initial forecast called for 9-13 inches. When it should have been readily apparent that more snow was being received, NWS decreased their total accumulation to 6-10 inches. When I teach meteorology classes, I always emphasize the need to pry yourself away from the radar estimates and look out the window from time to time. Very strange.

In any case, tomorrow looks to be a mostly sunny day and the end of our only real winter storm for the 2008-2009 season. Nearly half of the last 30 days have had high temperatures of 60 degrees or above. Yet another above average year resulting from regional (and ultimately, global) warming. Unfortunately, the National Renewable Energy Laboratories' instruments are indicating only 0.85 inches of water equivelant from this storm. We are still in a significant drought here on the Colorado Front Range.

Boulder at 12 inches at 11:00am, snow accumulating at 2 inches per hour!

2009-03-26T10:54:00.004-06:00

In one of the fastest accumulating snowstorms I've seen, Boulder is now buried under 12 inches of snow and the worst is still to come! Two inches of snow per hour are accumulating along the Foothills of the Front Range. The state of Colorado is quickly closing down - hundreds of flights from Denver International Airport are cancelled, portions of Interstates 25 and 70 are closed, and businesses and schools are locking their doors all around the area. Visibility on Broadway in Boulder has been reduced to less than 1/4 of a mile at times. Numerous traffic accidents reported around the city and the National Weather Service is urging everyone to stay home. Speaking of the National Weather Service, they have underestimated our snowfall totals in the local forecast.

I have many more photos, but no time to edit or post as I prepare my gear for blizzard conditions, which are supposed to hit us after noon and last through the night. I'll try to get more shots posted this later this afternoon.

Snow accumulating in Boulder at 1.5 inches per hour - over half foot at 9:00am

2009-03-26T08:48:00.008-06:00

We're seeing very rapid accumulation rates in Boulder. We just passed half of a foot at 9:00am, and there's no end in sight. The worst is yet to come - accumulation rates could increase to two inches per hour, and winds should start gusting over 30mph as the temperature plummets. A Blizzard Warning is now in effect for most of the Front Range. I'm forecasting two feet of snow for the Boulder area now. Travel is already becoming quite difficult, and I expect RTD (our mass transit system) will be shutting down shortly. The Subarus (my chase vehicles) are doing great in the snow, but the going is still slow.

I'm posting one shot now, but there will be more to come later as the snow dries out and gets whipped by the high winds.

Forecasted snowfall totals increasing; lots of gear rigging today.

2009-03-25T14:22:00.003-06:00

The National Weather Service has upgraded our Winter Storm Watch to a Warning. As of early afternoon on Wednesday, it appears that Boulder and surrounding Foothills areas will receive one to two feet of snow by Friday morning. Similar snowfall totals are expected along the Palmer Divide. This is truly a classic, upslope snowstorm produced by a Four Corners Low. The winds are increasing in Boulder and I'm watching substantial cumulus clouds growing to the north.

I've finished rigging the vehicle for in-motion image capture, and preliminary tests look good. A new hydrostatic ball platform is being ordered, but unfortunately will not arrive in time for this event. A little more gear prep tonight and everything should be ready for several hours of continuous shooting. More to come...

Spring storm systems have finally arrived on the Great Plains.

2009-03-24T17:20:00.006-06:00

Our first significant mid-latitude cyclone moved rapidly through the Great Plains yesterday. As I predicted, it dropped a couple of small and brief-lived tornadoes in the northern sector of the cold core low pressure cell. Nothing worth chasing up here, in terms of tornadoes, but the wrap around blizzard has been causing plenty of problems in the northern Great Plains and Midwest. The Dakotas could easily be looking at epic flooding in a few weeks.

The first real weather maker for the central Great Plains arrives later this week. From the beginning, this system has always looked more vigorous than the last in the forecast models. Right now, the Front Range looks to receive significant upslope winds. Combined with ample moisture, this should result in six to ten inches of snow for the Metro area, and probably more than ten inches of snow for the base of the foothills. These systems are usually accompanied by strong downslope winds on their backside, so I expect to see a lot of ground blizzards and general drifting throughout central Colorado as the system exits to the east. Across the rest of the Plains states, snow will be likely as well. Although there is nothing to indicate freezing precipitation events yet, I suspect sonde data closer to the time of the event will show a sufficient cold wedge near the surface and some freezing drizzle out on the Plains. If cloud depth is sufficient, freezing rain is a possibility as well. Time will tell! In any case, I will be chasing something by the end of this week and I'll post a photo or two early next week. Ahhh, spring break!

As I'm finishing typing this, the National Weather Service has issued a Winter Storm Watch for the Denver Metro area until 5:00am on Friday.

EDIT: This looks to be a classic Four Corners Low. If the forecast models verify, this will have very strong upslope flow, and perhaps the strongest we have seen in many months.

Unforecasted Bora Winds strike the Front Range.

2009-02-28T20:21:00.003-07:00

Sneaking "under the radar," hurricane force winds slammed south Boulder on Friday. Despite multiple surface indicators and nearly ideal 700mb conditions, the National Weather Service made no mention of winds over 25mph and failed to issue a High Wind Advisory or Warning. They also made no mention of dangerous winds in their Hazardous Weather Outlook. The storm lasted for about two hours and created zero visibility conditions on several highways. Some easy forecasting put me in exactly the right place at the right time. Despite my car being completely coated in clay, sand, grapefruit, toilet paper, and other random debris, I managed to get some great shots. I'll try to post one of these later after licensing considerations have been resolved.

Morning's surprise: Dense fog blankets the foothills of northern Colorado.

2009-01-15T21:55:00.003-07:00

Last night's surface maps indicated a very shallow surface moisture layer pushing up against the foothills. A high pressure cell in Nebraska was drawing the moisture toward Colorado with its anticyclonic flow. This morning, as forecasted, a layer of fog sat between 6000 and 7000 feet. However, it was much denser than forecasted. Visibility decreased to 300 feet for half an hour, and 1/10 of a mile for over an hour. Even the meteorologist at the local National Weather Service office was surprised when I relayed my observations. Perhaps needless to say, I ended up with a nice collection of dense fog shots, my second of this winter season. Between the high wind events and the fog, I have well over a thousand photos to edit so it'll be a few days before I have a chance to post any of them.