Saturday, August 6, 2011

Saturday - a day of rest (and a midterm)

This class started on Monday and has been non-stop since. So we had built in an opportunity for a rest, and today was that day. To get it out of the way, the students took the midterm from 0930-1030, and then loaded up and headed out to see the Grand Canyon. Along the way, smoke from fires was noted, as was a pyrocumulus (photo to follow!) As usual for some of the students, this was their first view of the Grand Canyon, and it never fails to impress and inspire.

Before dinner, we worked out a plan for tomorrow. The monsoon occurs in surges. First, a surge of moisture gets carried northward from south of the border. This then serves as the moisture that forms the clouds and thunderstorms of the monsoon. After a few days, the moisture plume gets shut off for a variety of reasons, and things are quiet (cloud-free, no storms) for a few days. And then the cycle repeats. We had been hoping to catch a surge developing, and it looks as if tomorrow is the day! So the plan is for one group to drive fairly far south (almost to Phoenix), a second group to stay in FLG, and the third group to head midway (Sedona-Cottonwood). At certain times, each group hopes to launch a radiosonde. This will give us a good north-south picture of the developing moisture surge! Fingers crossed it will work!!!

Friday - the atmosphere dries out.

I am told that at one point today, the air temperature in Needles (CA) reached 106oF and at the same time the dew point temperature dropped to -14oF, yielding a dew point depression of 120oF!!! Close to a record, but not quite. But STILL!!!!!

Translation...some really dry air had moved in (as forecast and expected) from the west, thus shutting down chances of convection. In fact a few storms did brew up, some giving flash flooding out in the Wallow fire area, but none in FLG. So we designated today as an "instruments" day, and we had some good experiments planned.

As usual, the bleeping instruments were having a bad day. Do instruments ever work all the time??? Imagine having a laptop or desktop that only worked 30-50% of the time you turned them on! So the $180,000 radiometer - which is virtually brand new, and which had worked OK at SJSU, and which we had shipped out to FLG to leave in one location and gather a TON of atmospheric profile data - of course refused to work (just like the sodar in year 1). We did gather some data, namely the EXACT elapsed time after switch-on that the radiometer would die: 4.5 minutes. Nobody real happy.

Each year, we have brought one extra radiosonde system with us! This year we have added a Vaisala system to the GRAW and IMET systems. This gives plenty of opportunity for multiple launch-type experiments. Assuming everything works. Which usually, it doesn't. The high point was a launch at the same time as the official NWS FLG OOZ radiosonde launch - both profiles look very similar, including both showing a very dry layer up above about 500 hPa (encouraging!) The low point was a balloon snagging one of a million pine trees nearby on its way up. Reminded me of every Charlie Brown strip!

The day wasn't a complete loss, although the main plan had been to compare radiosonde (working) and radiometer (dead after 4.5 mins) soundings. After the OOZ launch, the students drove NW of FLG to set up a RAWS station which we will leave to get 24 hours of data. The data may or may not be exciting, but the experience of setting up the RAWS is good.

Oh - and I fell and bumped my head, saw stars, and decided to be on the safe side and spend a couple of hours at the ER making sure the brain is still working at fever pitch. Which - it is! I am sporting a nice bump on my head!!

Friday, August 5, 2011

Thursday - we REALLY get rained on !!!


No doubt about it - today was spectacular! In the previous two years we had noted storms forming preferentially in the Prescott area, so we decided to make that our destination for a day of - hopefully - good storm chasing and measuring. The other choice was the Winslow-Holbrook-Show Low triangle. Anyhoo, off we went to Prescott. Conveniently (!), Sedona is on the way, so we were forced to have lunch there, and then headed southwest towards Prescott. But we never got there on account of as we had driven through Cottonwood and were heading uphill out of town, some wonderful storm clouds hove up before our eyes. And so we thought - why not? - let's just pull over here.

Which explains why some/all of us spent the next 2-3 hours at the roadside just west of Cottonwood. Several good cells came overhead moving in a generally WSW-ENE direction. One featured heavy rain and pea-sized hail, our first hail of the trip. All featured lightning which caused much excitement. We set off a radiosonde, and apparently got a good sounding (I haven't had time to look).

There was a schism in the ranks between driving on towards Prescott (idea quickly dropped since our location was just fine!), staying roadside, or heading back into Cottonwood which was clearly under a downpour. So 1/2 the students and I jumped into one van and shot downhill into town. There, we encountered signs of a just-completed cloudburst, namely widespread street flooding - see the video above! - and culverts awash with floodwater - video to come! It was intense!! We did manage to catch up with the rear side of the receding storm, but it's actually hard to "chase" a storm. Much better to get out ahead of it, sit and let it roll over you. This is where the students' forecasting skills are coming into play!

After this, we were like little kids at the fair running around with excitement. We found a strip mall with an overhang, and spent the next two hours standing under it during intense downpours, watching lightning, and venturing out to see flooding afterwards. Which is why we got back to the hotel with soaked shoes :-(

Meanwhile, the other team back on the roadside released another balloon (we got in trouble for too much watching and not enough measuring!). And apparently they had some sort of comedy action when lightning struck VERY close, and they almost broke the world record for getting back in the van! Except that Neil kept failing at the ancient art of jumping into a van door before it closed. Apparently there was also some sort of rain dance after a successful launch, but I haven't seen the video yet!

It was a great day! We successfully forecast the location of convective activity (well, roughly), and managed to launch balloons into the storms. We also measured large variations in winds, and air and dew point temperatures as each cell approached and passed. And of course we saw the flash flooding!

Despite being pooped (post-excitement adrenaline crash), we had another forecast session which again ran 'till about 10:30 - long day! Hard work! But it's paying off!

I'll be creating a separate post with just videos - look for it!

Wednesday, August 3, 2011

Wednesday - we get rained on!!

Since we expected rain and storms today (and since in the past we always arrive too late for the action), we gathered at 7 am to get an early start. This lasted all of 5 minutes as it was decided that it was VITAL to drive across the street to Starbucks. Imagine many of us in line for coffee, combined with a herd of bikers doing the same (and probably on their way to Sturgis). So really, we left at 7:30, but that got us into Flagstaff at 2:30!! We had lunch in Seligman at the Roadkill Cafe, a charming little joint. "You kill it-we grill it".

As you can see, the skies were getting more interesting, and as we approached Flagstaff we decided to focus on one good-looking cell to the south. So we shot south on I-17 towards Phoenix, descending rapidly over the rim, and found a fine place to stop and view. Unfortunately, the "good" cell had beat us east of I-17 and was dissipating, but we got great views of numerous showers to the west, south and east.

In fact that seemed to be a theme for the day...cells all around FLG but none over it. A spell that broke at about 9 pm in the middle of our forecasting session. Thanks to Allison for noticing the sound of rain outside. Seconds later we were all standing out in a downpour like kids! Big fat cold raindrops, lightning and thunder - all chased us in pretty quickly!

Oh - and thanks too to Allison for the highly entertaining reaction - almost interpretive dance really - to a massive giant bug that flew in and around. It was the size of a small hummingbird, so it could have been one of those new drone things!!! But it's dead now, thanks to Craig-the-bug-killer.

Tuesday - we leave!!!

Last-minute preparations...adding the Airmar to the roof (it logs and displays current conditions as we are driving). We've got this thing down to a tee now! None of the "running around with our hair on fire" like the last two years. And amazingly - we drove off at 10 am!!

The day's drive was relatively uneventful. The lunch stop at Coalinga ("Harris Ranch") was as stinky as ever, we drove right past Craig's house in Bakersfield (and waved!), and the high desert was high and "deserty". Once again we didn't see ANYTHING interesting near Edwards AFB. I always assume we'll be strafed by top-secret jets, but nothing.

Clouds on the eastern horizon - promising for tomorrow! Overnight in Barstow at the Ramada Inn. Kudos to the manager of the Sizzler who gave us a 10% discount for showing up as a crowd - thanks! The Ramada, on the other hand...most of us could not get the wireless to work. The desk clerk gave us a phone number to call for help...not helpful. The lack of internet killed our plans to forecast in detail on our first night. And since we expected today to be active, it was a drag not being able to get a head start on forecasting.

Monday - class starts!

Today was the first official day of class, and I spent my day...doing unrelated paperwork and basically going crazy trying to get ready. And remember to do everything! Meanwhile, the class assembled and everybody showed up on time. Allison Charland and I both did quick overview talks, and Marty Leach taught a morning and an afternoon forecasting workshop. This year, we're running IDV on the laptops which will give us a whole new way of "seeing" the weather - exciting!

At the end of the day, Allison led the students to the roof to do a test balloon-radiosonde launch (it worked!) Moral of the story...add more helium!

All raced home to pack!!!

Sunday, July 31, 2011

Sunday welcome!

It's Sunday the last day of July 2011, and the field trip starts tomorrow! Yay!

The class this year is back to one day on campus (tomorrow), followed by departure for Arizona on Tuesday. The Arizona atmosphere is moist and active right now. Too bad we're still here, as it's forecast to dry out over the next few days.

We have lots of plans for forecasting and measuring, and we'll have a blast - whatever the weather!!

Stay tuned!