Wednesday, December 31, 2008

History And Honors

I am proud to announce that the Big Sky Convection blog has been chosen among the "100 Best Blogs for Earth Science Scholars" according to the BachelorsDegreeOnline.com blog.

You can find the listing as #48 on the list in a section for Meteorology blogs. I'm honored that this blog is listed among exclusive company: chaser/blogs such as Carlson Chasers Blog by the Carlson clan, Steve Miller (Oklahoma)'s HamWx, Mike Umscheid's High Plains Drifter, and Jon van de Grift's Perilous Planet

Thank you for the honor!

This started me thinking about how I wish I would have kept an active meteorology blog running as long as I have been online. When my family first got America Online in 1995, I immediately found the "weather chat". I made a few friends through this chat room and began publishing a newsletter which I called the "LepWx&News" (the "Lep" coming from my screen name at the time, Leporinis). This newsletter was sent out to the e-mail address of people I met through the chat and personal contacts. It included personal weather stories, some climatological information, and a few pictures.

That newsletter eventually went by the wayside and I would occasionally include meteorological discussion in my personal blogs but it wasn't until moving to Colorado that I had the opportunity (mainly due to proximity) to chase storms. Sure, I did that in Montana ... usually driving out to an couple preferred overlooks to experience the storms as they rolled in, but it's different here. Being here in Colorado, I definitely feel more like part of the meteorological community. Going to school and completing my degree in meteorology has helped, but back in Montana, aside from the local TV weatherman, I didn't know a soul who was interested in meteorology. So, with this blog, I'm reaching out, trying to expand my knowledge and opportunities. If I can help one person be more interested in meteorology or just teach someone something, than the purpose is served. I suppose this is a great way to end this year and embark upon a new one. Maybe tomorrow I'll put out a "looking forward to 2009 blog". For right now, I'm on my lunch break at work and have limited time.

So, a bit about the weather:
The Front Range of the Rockies experienced quite the wind storm on Monday night / Tuesday morning. Here are a few obs I pulled from the NWS page:

0400 AM NON-TSTM WND GST 3 S MASONVILLE 40.44N 105.20W
12/30/2008 M111 MPH LARIMER CO TRAINED SPOTTER
0442 AM NON-TSTM WND GST 7 WNW BERTHOUD 40.34N 105.20W
12/30/2008 M98.00 MPH LARIMER CO TRAINED SPOTTER
0706 AM NON-TSTM WND GST 2 N LONGMONT 40.20N 105.11W
12/30/2008 M86.00 MPH BOULDER CO TRAINED SPOTTER
0731 AM NON-TSTM WND GST 9 SSE BOULDER 39.91N 105.19W
12/30/2008 M87.00 MPH JEFFERSON CO MESONET

It was 55ºF when I got home from my trip on Monday night. The temperature remained in the mid to upper 50's until yesterday (Tuesday) afternoon when a cold front of sorts backed into the mountains. The airmass behind it wasn't much colder, so to speak, but it prevented the Chinook winds from keeping the area warm. In fact, we cooled from 59º to the upper 30's before the sun went down. It was ... dramatic.

And finally, a little peek into the tropics (which are pretty quiet right now!).



Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images.

Dann.
PS: I will try and get some photos from my trip to Montana up soon. Hope you all have a nice New Year!

Monday, December 29, 2008

To Wrestle The Wind

I'm back in Colorful Colorado. My trip to Montana was great. We had at least four different dendritic snowfall events including one on Christmas Day (talk about a "white" Christmas!)

Travel could have been a lot worse. On the way up, I only had to contend with wind in Wyoming (north of Cheyenne) and then again near Livingston, Montana (with blowing snow). The passes in south central Montana were snow packed but not icy. On the way back to Colorado, the snow ended in Butte just as I was leaving. The sun came out and made Homestake Pass slushy, but not slippery. The roads were dry after that and I only dealt with insane wind once south of Buffalo, Wyoming. Checking obs along the path, I was battling 30-50mph crosswinds at times! No wonder my arms are sore. There wasn't any blowing snow in Wyoming ... just blowing dust. It was very hard to see at times.

When I left Denver, it was cold. We had been battling inversions for almost the entire month of December. When I pulled up at my apartment this evening, the temperature was 55ºF with stiff southwesterly winds. Finally, some of the snow has had a chance to melt.


Anyway, that about wraps up the weather side of things. I took a lot of pictures but haven't had much time since being home (only an hour now) and really haven't gone through them. So, I'll share my favorite one since it came out well and I don't really have to do anything save for slapping a watermark on.


Bell/Diamond Mine (Gallows/Head) Frame
Butte-Silver Bow County, Montana
10:47PM MST December 28th, 2008
(click for larger image)


Dann.

Tuesday, December 23, 2008

Happy Holidays

I'm off to bed now ... or in a few minutes anyway. When I wake up at 5:20, I'll be embarking on my annual journey to visit family in Montana for the holidays. It's an 800 mile, 11 hour drive ... nothing for "never overnighter" storm chaser. I'll be checking in periodically (either here or on Facebook). Otherwise, I'll be back early next week.

I wish you all a Merry Christmas and Happy Holidays. For me, Christmas is about spending time with those that you love and being appreciative of life. May you all be blessed.

Dann.

Denver Weather, Severe Probs, and Australian Tornado

Last night at 8PM (MDT), the temperature outside my apartment was 20ºF. Two hours later, it was 36ºF (10PM). While KAPA had been in the 30's all afternoon and into the evening, other stations such as KBKF and KDEN were still inverted. I had made pleas to the universe in general yesterday to have the southwesterlies break the inversion just for a spell. For a brief period last night, they did just that. It was down in the 20's again this morning when I awoke.

We had a brief burst of snow here near Centennial Airport today. I did see some cumulus this afternoon which made apparent the instability today. It made me think of much warmer times ...

Speaking of warmer times, I'm keeping my eyes on the trough portrayed by the models that should plow its way through the south this coming weekend. The models aren't quite lined up yet and vary a little run to run, so I'm not going to call anything yet. Indications are that the Gulf of Mexico will open up, though.

Here's a look at the CAPE on the WRF 84hr. (Friday evening)



Current tropical activity:





Looks like Billy might make a name for himself. After an initial landfall in Australia, he's emerging out into favorable strengthening conditions. We'll have to keep an eye on him.

Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images.

And finally, a nice tornadic storm is caught on camera in Australia:
Link to large picture.
Discussion on The Australian Severe Weather forum.
Canberra Times article.

Dann.

Monday, December 22, 2008

Late December Severe Event?

Well, well, well, what have we here? Chaser friends are abuzz with a late December chase possibility. I will, of course, be enjoying the company of my family seemingly above the Arctic Circle in Montana. If the models verify, we will have a strong weather-maker crossing the CONUS. It looks squall line-ish, but you can't rule out some spin-ups, especially if we can work out some supes just ahead of it. It will be interesting to watch for the next few days.




SPC even has a Day 5 out on the situation already. I haven't seen one of those in at least a month.


And one final thought ... current tropical activity.





Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images.

Dann.

Saturday, December 20, 2008

Cold Cut Switchblade

Well, it's getting a little chilly here again tonight in Denver. As it stands, it's 16ºF with a light breeze at my apartment. The sun was out most of the day, but it never really got much above 30ºF. While that doesn't seem all that cold, the wind sure had a knack for cutting right through me.

Montana is seeing very cold weather again. Temperatures dropped below -20ºF in many locales yesterday and have returned that low already tonight. The GFS and WRF did not show the quick drop in temperature tonight for the area. I wonder if they are having trouble with the timing of the system in the northwest. The warming in Montana just doesn't seem to have begun just yet. In fact, there are some readings below -25ºF currently and even one (Kevin, MT) at -31ºF.

Last night (Friday, the 19th) was the third installment of Convergence! The AMS Club at Metro State was kind enough to host the event and it took a slightly different turn than normal. Instead of just hanging out at the bar and swapping stories, we had a forum to share media. It was a lot of fun (-beer).

I was asked to fill some time so I did a presentation on the Alta Vista Tornado. More specifically, I wanted to talk about how sometimes storm chasing is just about going out and working with what you have. It seems like a lot of attention is paid to the moderate to high risk events. Well, in this case, we saw something happen one day, saw the same pattern the next day, and got lucky. I also wanted to show people that a non-traditional storm (in this case, a VERY LP-supercell) can still tornado under the right circumstances. I tried to cover this as best I could given the documentation that I had. However, my power-point presentation did not make it to the event intact. Unfortunately, I only linked the diagrams and pictures instead of inserting them. So, of course, nothing showed up. Luckily, I was able to talk my way through with some stuff I had uploaded to the infobahn and a couple secondary things that I had remembered to bring. Hopefully people enjoyed the talk.

Tony Laubach was up next and he presented the May 29th chapter of his latest chasing DVD. I had already seen it, so I knew what to expect (though thoroughly enjoyed it for the third time!), but it was cool to hear the oohs and ahhs from the audience.

Next up, we got to see some of the May 22nd chapter of the latest Carlson Chasers DVD. I had seen some bits and pieces before but it was nice to see the full presentation. I still need to pick up a copy of their DVD.

Cameron Redwine then wowed us with some slide of his storm photography. He doesn't have much material online or I'd link him, but he has some fantastic shots. He's been chasing in Colorado since 1997 and has documented completely with use of a film camera. It definitely gave me an appreciation for the film quality.

Kendall LaRoche was next and he showed some pictures of his front porch storm spotting, which was cool. I had the pleasure of bringing him along on his very first storm chase back in April. You should have seen his face the first time we saw lightning on that particular day.

Finally, Dr. Richard Wagner (from Metro State) did a presentation of below-zero climatology for Denver and finished it up by talking El Niño and La Niña trends here.

There were some new faces there, which was nice. Some of them were chasers and some of them not. All in all, it was a fun night.

The next event is tentatively scheduled for Saturday, January 31st.


A couple days ago, I promised some shots from our grauple/thundersnow event. Though I didn't hear thunder, there were several reports in the metro along with some lightning strikes showing up.






I've enjoyed putting the information on the tropics in my posts for the past week. For some reason, the last couple years have seen me more excited about the Southern Hemisphere season than the more "local" events. I guess if you're reading this, let me know if you like seeing the tropical weather on here.




Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images.

And finally, Michael Carlson posted this link on Storm Track recently. I figured I'd share it as well.

The Big Picture (2008 Year in Photographs)
Part I
Part II
Part III

Dann.

Friday, December 19, 2008

December Convergence! & The Tropics

December's Convergence! is tonight.

It will be held at the Tivoli Student Union Building on Auraria Campus. I will be doing a short presentation on the Alta Vista Tornado. It's nothing special really, I'm just trying to help fill time. It will focus on some of the mesoscale features and be filled with pictures and video.

Starts at 5:30PM tonight (hopefully I can get there on time!).

Did I mention free food and drink?


Also, I've been enjoying the tropical cyclone season in the Southern Hemisphere, so here is an update.

Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images.





UPDATE on yesterday: The snow came quick yesterday and was gone. There were some reports of thundersnow east of town and lightning detection did show a couple strikes.

I'm not sure how much updating I will be doing over the next week and a half. I have a busy weekend ahead and two long days in the office, Monday & Tuesday. I will be traveling to Montana for Wednesday through Monday and my parents have dial-up. :)

Dann.

Thursday, December 18, 2008

Nature Is Go'n'a Get Ya'

Nothing ground-breaking to say today, so I'll let the pictures and video do the talking.

I stumbled upon the following graphic on AOL News yesterday and it gave me a little chuckle. There have been several other versions of this map published in the past 24 hours, but I think this is one of the more simple ones to look at and understand. It basically describes how likely you are to be "dead by nature" by region.




The cold air has moderated over the last couple of days. The storm system that brought snow to Las Vegas yesterday has also plowed over most of the west. Everybody seems to be getting snow. We have a few showers in the Denver area right now, but nothing to write home about.

The situation developing in the midwest and Ohio Valley should be interesting over the next few days. Death, destruction via ice and snow. Prepare for those headlines.

... but, the cold air will return to the northern Rockies as exemplified in this forecast pulled from the Butte, Montana NWS point forecast page.



Looking in on the warmer latitudes ...




Satellite image used with permission; courtesy of IPS Meteostar Inc.



On the lighter side, this was posted over on Storm Track today.


Weather Channel Accused of Pro-Weather Bias





UPDATE:
We just had a nice graupel shower a minute ago. I took some pictures but don't have my cable with me. Hopefully I'll have them up tomorrow.

UPDATE 2:
Quite the wave of showers that have just come off the mountains. We could be seeing some heavy snow with embedded small to moderately sized graupel. I wouldn't be all that surprised to see reports of thundersnow. Lightning is quiet for the time being, but I'll keep my eyes out.



Dann.

Wednesday, December 17, 2008

Cold Tropical Explosions

Okay, a couple little updates today.

Going back and looking at climatological data, I found that the actual lowest temperature in the lower 48 (at least) on December 15th was -39ºF at a COOP observing station along the Canadian Border (6N Simpson, Montana).

On the 16th, both Harlem and Chinook, Montana reached -35ºF (as well as Longville Minnesota as I previously reported.

And finally, here are some not-so-cold things to consider...

In the tropics:
04S (South Indian Ocean)
40kts / 993mb

Click for larger image. Satellite image used with permission; courtesy of IPS Meteostar Inc.

And a giant explosion on the sun. (posted by someone over on Storm Track)



Thanks for shopping,
Dann.

Tuesday, December 16, 2008

More Cold Than You Can Shake A Popcicle At

Well, how about another update on the cold?

-Denver tied a 111-year-old record by dropping to -8ºF this morning.

-Also, Butte, Montana crushed a record low maximum for December 15th at -9ºF. The previous record was 0ºF.

-The coldest spot in the nation this morning was Longville, Minnesota at -35ºF.

Select Montana minimums for December 16th:
-28º Jordan
-27º Cut Bank
-27º Wolf Point
-26º Glendive
-25º Glasgow
-24º Dillon
-24º Great Falls
-23º Lewistown
-22º Bozeman
-22º Butte
-22º Havre
-22º Sidney
-21º Baker
-20º Miles City
-17º Helena
-17º Malmstrom Air Force Base (Great Falls)
-17º Livingston
-16º Kalispell
-15º Billings
-15º Missoula

If the GFS verifies, we're looking at another cold weekend in the northern Rockies and adjacent plains.


And now, some pretty picture (click for larger) from contributors.

The first two are courtesy of Alan Clark of Rock Springs, Wyoming. Fantastic shots of halos and a moon dog. According to Alan, the pictures were 8 second exposures taken at 100 ISO. They were taken in Rock Springs at 6:30PM on December 11th. Thanks Alan!




The next photo comes from Cassie Robinson in Fargo, North Dakota. I believe it was taken early on the 15th.



Dann.

Monday, December 15, 2008

Continuing Cold

Well, since I was tracking temperatures in Montana yesterday, I figured I'd update a few today. I'm just including the METAR sites this time as there were not outstanding intermediate readings.

Note, these are not official climatological lows for any specific period. They simply are the lowest reported reading or reported minimum within the last 24 hours ending today at 22Z.

-33º Havre (with wind chills approaching -60ºF!)
-32º Glasgow
-32º Jordan
-29º Glendive
-29º Lewistown
-28º Wolf Point
-27º Dillon
-26º Baker
-26º Great Falls
-26º Sydney
-25º Cut Bank
-23º Miles City
-19º Billings
-17º Butte
-16º Helena

The -33ºF in Havre was the lowest observation that I could find. That is cold!



...

Not to be out done, Denver experienced some cold this morning as well. I was coming back from a graduation party at * ahem *, four this morning and I noticed that it seemed "Butte-cold" out. What do I mean by "Butte-cold"? Well, growing up in Butte, Montana, during similar arctic air masses, the cold air would often sink into the valleys of southwestern Montana creating extremely cold pockets of air. I've seen as low as -48ºF and been outside at -46ºF (imagine me sitting in my living room in back in the late 90's, preparing to go out and deliver newspapers when turning on the Weather Channel and seeing THAT on the local forecast). It felt similar in Denver this morning as the cold air hugged the lower areas in the Front Range. It was cool to see all the refineries in Commerce City and their billowing steam plumes coming to an abrupt stop at the top of the inversion. One refinery had a nice flame on the top which was flickering and illuminating the "cloud deck" almost making it look like there were explosions occurring. It was very odd.

Speaking of inversions, check out the sounding from this morning!


Click for larger image.
From http://rap.ucar.edu/weather


Now let's talk temperatures...

Minimums from official stations in the Denver area this morning:
-19º Denver International Airport
-13º Buckley Air Force Base
-11º Rocky Mountain Metropolitan Airport
-9º Centennial Airport


Minimums from elsewhere along the Front Range and Northeast Colorado:
-20º Greeley
-18º Fort Collins
-16º Sidney, NE
-15º Akron
-13º Cheyenne, WY
-9º Pueblo
-8º Colorado Springs

UDFCD Mesonet Minimums:
-21º Brighton North
-18º Brighton
-17º Pump Station 3 (E Aurora)
-16º Button Rock (Boulder County)
-13º Louisville Lake (Louisville)
-13º Urban Farm (Stapleton-Denver)
-10º Highlands Ranch
-9º Aurora Reservoir
-9º Aurora Town Hall
-9º Quincy Reservoir
-8º Diamond Hill (W Downtown Denver)
-8º Ward (Boulder County)
-6º Squaw Mountain (Clear Creek County)*
-1º Hiwan Golf Club (Jefferson County)*
2º Elbert*
5º Cal-Wood Ranch (Boulder County)*
5º Sugarloaf (Boulder County)*
7º Blue Mountain (Jefferson County)*
11º Castle Rock*
* stations at higher elevations either in the foothills or on the Palmer Divide

Wow, that's cold for Denver! The low at the airport of -19º smashes the record by 15ºF!!


Elsewhere in the world:
Click for larger image.

This is Typhoon 27W Dolphin. Figured that might warm you all up just a bit.

Satellite image used with permission; courtesy of IPS Meteostar Inc.

Dann.

Sunday, December 14, 2008

Enter: The Cold

Last evening, I was sitting a long table celebrating Tony Laubach's graduation (double major) from Metro State when the weather outside turned frightful! We had enjoyed a high in the mid 50's yesterday, but while the revelry took place, a strong front plowed down the Front Range, dropping temperatures forty degrees or so and providing lift for some snow showers. While I didn't end up with much snow (not measured, but estimated at 2-3"), the wind blew it around into some nice drifts. Not to mention the fact that it bottomed out at 0ºF at my apartment. (Denver International Airport saw -3ºF).

The sun is finally out now ... just in time to head to more parties of the holiday and graduation variety. But first, let's talk about the cold farther to the north.

I've done an unofficial minimum temperature survey of various stations in Montana and have come up with the following list. Keep in mind that quality control may be lacking as many of these observations came from Montana's SNOTEL and other various mesonets in Big Sky Country.

METAR sites:
-25º Lewistown
-24º Cut Bank
-23º Great Falls
-20º Havre

OTHER STATIONS:
Rocky Mountain Front Area:
-34º Waterton National Park Gate (ALBERTA, CANADA)
-30º Mount Lockhart
-28º Badger Pass
-27º Browning
-26º Many Glacier
-25º Sweetgrass
-24º East Glacier Park
-24º Saint Mary

Central Montana Mountains (Big, Little Belt Mountains, Crazy Mountains):
-33º Crystal Lake
-30º Pichfoot Creek
-30º Boulder Mountain

Southwest Montana Mountains
-25º Big Hole Pass

Right now, the colder readings are starting to come from far NE Montana and the Dakotas. Temperatures are still falling in the area with strong winds. Wind chills are touching -50ºF in some areas. Blizzard warnings have been dropped in Montana, but remain in the Dakotas.


So congrats Tony!

... and it's currently 4.6ºF and sunny here!

Dann.

Hawai'i Tornado Warning

Someone on Storm Track mentioned that there was a tornado warning for the island of Kauai, Hawai'i yesterday. Immediately, I thought waterspout, but by checking out the radar, I'm convinced otherwise. There was some wind damage reported (click here) but no confirmed tornado. Anyway, I've included the warning text below as well as some radar images:

BULLETIN - EAS ACTIVATION REQUESTED 
TORNADO WARNING
NATIONAL WEATHER SERVICE HONOLULU HI
1241 PM HST SAT DEC 13 2008

THE NATIONAL WEATHER SERVICE IN HONOLULU HAS ISSUED A

* TORNADO WARNING FOR...
THE ISLAND OF KAUAI IN KAUAI COUNTY

* UNTIL 115 PM HST

* AT 1234 PM HST...RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF
PRODUCING A TORNADO 7 MILES SOUTHWEST OF KAUMAKANI...OR 24 MILES
WEST OF LIHUE...MOVING TO THE NORTHEAST AT 35 MPH.

* THE TORNADO WILL BE NEAR...
KEKAHA AT 1245 PM HST
WAIMEA AT 1250 PM HST
HANAPEPE AT 1250 PM HST
6 MILES SOUTH OF HANALEI AT 115 PM HST

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. TAKE COVER NOW! IF YOU WAIT
TO SEE OR HEAR IT COMING...IT MAY BE TOO LATE TO GET TO A SAFE PLACE.




CLICK FOR LARGER IMAGES

Base Reflectivity (0.5º)


The next three are consecutive storm relative velocity scans at 0.5º.



Wow! Nice little couplet there!



Radar images used with permission; courtesy of IPS Meteostar Inc.

Dann.
PS: Update on snow and cold possibly later today. Also, some awesome moon halo images sent in by a friend.

Saturday, December 13, 2008

Winter Eve

Well, well, well ... I'm sitting pretty here in Denver. Right now, temps are in the 50's and air is descending off the mountains giving us some strong southwesterly winds. There is some turbulence in the lee of the mountains giving us a few clouds, but mostly we're just enjoying a partly cloudy and reasonably warm day.

Other places aren't fairing so well. I'm "nowcasting", if you will, for my parents, who are driving from Boise, Idaho to Butte, Montana today. They just encountered a strong snow band north of Idaho Falls which is attributed to a strong surface low there (it's quite wrapped up on visible satellite). The road ahead won't be anything easy, however, as most observations along the path are between 4 and 7" of new snow ... and a howling north to northeast wind. In fact, temperatures in southwest Montana have dropped below zero.

Meanwhile, in Eastern Montana, the storm is just cranking up. I checked in with my cousins in Billings and they report plenty of new snow and plenty of wind. Earlier today, SPC issued a "blizzard" mesoscale discussion for the area. In fact, most of Montana and the Dakotas are under a blizzard warning for the next day or so.

In the wake of this storm, which should continue to pound the northern tier, the cold air will settle in. Many locations will see -20ºF to -30ºF with wind chills even lower. This looks to stay around for a while as well, especially if the GFS verifies. The upper level pattern really doesn't modify in the 180hour time frame, with the persistent trough in the west and ridge in the east allowing the cold air masses to advect down along the eastern slope of the Rockies and the northern plains. Even at the end of the week, the GFS is showing lows in Montana back to -30ºF again.



A little further to the south, Colorado may see a few quick inches tonight and brief showers of snow in the coming days as little perturbations ripple in the flow. However, the western slope seems to have more heavy snow potential.

Dann.

Friday, December 12, 2008

Hoobler says name it: "______".

It's been a bit since I've updated, so I figured I'd stop in an let everyone know that I'm still alive.

Let's talk about the weather!

We had what I would almost call an "outbreak" of severe storms in the southeast on Tuesday ... and then yesterday, snow! Snow in Houston ... snow in New Orleans ... up to 8-10" in SW Mississippi! Quite the storm.


(snow still visible on satellite)

Now ... we have more excitement coming down the pike. The east looks locked in a ridge for the next few days, while the west (especially the northwest) will see persistent upper level troughing. Did I mention it is going to get cold along the northern tier? I can almost here the "I'm not a meteorologist, I just play one on TV" mets screaming ARCTIC OUTBREAK!!!!

Well ... I suppose they won't be too far off:

Thursday, December 04, 2008

Denver Cyclone Snow & December Convergence! Announced

I woke up to a dusting of snow yesterday morning as a cold front plowing south along the mountains gave us a brief upslope event. A secondary surge was forecast for today, bringing with it a deeper upslope and a better chance for snow. I wasn't paying too much attention to anything until I heard on the radio this morning that the Weather Service had suddenly upped snow predictions.

When I got to work and had a look at things, I saw this:
(click for larger image)


Hello Winter-time Denver Cyclone! (I guess it is still Fall, but still...) The Cyclone tends to form a day or two after passage of a Canadian cold front when the surface flow generally has a south and east component. We were a little more east than south today, but the return flow along the foothills gave us enough spin to categorize the cyclone. It was gorgeous on radar, with a nice convergence boundary setting up from DIA curving south and west toward Elbert. Very cool to see today. I don't have any specific links ... but do a search for "denver cyclone" or "Edward J. Szoke" and you should turn up some good results (if you're looking for more info).

Anyway, it seems that the forecast may have been increased as a result of this formation, which can amplify precipitation (and mesoscale vertical motion) in the area. At my apartment, we saw about 3-4" and we're a little on the chilly side at 13ºF currently.

... okay, so I went out and checked ... 3.5" of very light, fluffy snow. I don't have my gauge set up at my new apartment, but I'd estimate the water content at somewhere between 1/15 and 1/20.




ALSO! I'm happy to announce that Marta Nelson, who succeeded me as president of Metro State's Student Chapter of the American Meteorological Society when I graduated, has organized a big get-together on December 19th. This will be the December "Convergence!" and I am going to cancel the January 3rd meeting. This Convergence! will be held at the school in a large-capacity room with plenty of guests and probably an opportunity to show video. More details to come.


Dann.

Radar image courtesy of IPS Meteostar Inc.