Saturday, January 31, 2009

12P Ellie

Earlier this week, the GFS was resolving what would be a monster Nor'Easter for the East Coast early next week. Since then, it has progressively put cyclogenesis further off the coast, and not having the storm impact the east as much as once was thought.

Meanwhile, whispers are abound of a possibly chaseable southern plains severe event next week ... I'm definitely keeping my eyes on that one.

Tropical Weather:



12P Ellie - This storm has been watched for the past few days, hanging off the coast of Australia. It has had impressive surface circulation and for whatever reason, as it is now impacting the coast, it has been quickly upgraded to a Category 1 Cyclone. (equivalent to a tropical storm at 35kts) JTWC hasn't been warning on this storm just yet (as I write this), but Australia's Bureau of Meteorology has, with the warning located here. (Forecast graphic below)


I've also included a sweep of the Cairns WF 100 C Band Radar and annotated the approximate position of Ellie's center of circulation.


And in the Southern Indian Ocean, we have a nice area of investigation. There is no official "formation alert" on this storm yet, but it sure "looks" good. You can see the impressive ball of convection and the circulation of the lower clouds.



Dann.
Currently at Denver (Hampden Heights), Colorado: 63ºF Mostly cloudy (high clouds), winds south, roughly 5kt.

Overview tropical satellite imagery used with permission; courtesy of IPS Meteostar Inc. Tropical tracking information and radar imagery provided by the Australian Bureau of Meteorology. Annotations are made by the author of this blog. Click for larger images.
**NOTE: If you've reached this page due to a search result, the most current tropical information can be found in the latest post and not necessarily the post you are reading. Visit http://blog.bigskyconvection.com/ for the most recent post.

Wednesday, January 28, 2009

Hettie

Let's start with the tropics today as there isn't much else going on. Here is the current overview:


11S Hettie - The only active cyclone at the moment. I predicted yesterday that it wouldn't make it to named-storm strength, but I underestimated it. It still doesn't look great, but the surface circulation is pretty tight.






I added the following image because it is interesting to see the convection completely displaced from the center of circulation. This was from earlier today.



The following image is from 91P Invest. I included it only because you can see the low level circulation just coming onshore.





Finally, Chad Cowan compiled the year's 10 best tornado videos. You can check them out on his blog on ChaseTheStorms.com.

Dann.
Currently at Denver (Hampden Heights), Colorado: 28ºF Partly cloudy and calm.
Overview tropical satellite imagery used with permission; courtesy of IPS Meteostar Inc. Tropical cyclone tracking information and some satellite imagery from Navy/NRL Tropical Cyclone Page. Additional satellite imagery from JTWC. Annotations are made by the author of this blog. Click for larger images.
**NOTE: If you've reached this page due to a search result, the most current tropical information can be found in the latest post and not necessarily the post you are reading. Visit http://blog.bigskyconvection.com/ for the most recent post.

Tuesday, January 27, 2009

Colorado Snow Totals

The sun! It came out today ... and it was kind of nice. Temperatures crept up toward freezing today, which was nice. Elsewhere, especially to the north and west, it was quite cold. Wisdom, Montana bottomed out at -35ºF while in Wyoming, both Greybull and Shirley Basin touched -37ºF. Brr!

The tally is in on Colorado snowfall. The local NWS office posted the following map today:


Currently in the tropics:


It seems that 98P lost some steam today, so I would wager it wouldn't quite make it to a named system. There are a couple of areas of thunderstorms on the northern Australian coast that bare watching. Otherwise, it's pretty quiet.

Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images. Annotations are made by the author of this blog.

NOTE: If you've reached this page due to a search result, the most current tropical information can be found in the latest post and not necessarily the post you are reading. Visit http://blog.bigskyconvection.com/ for the most recent post.


Dann.
Currently at Denver (Hampden Heights), Colorado: 23ºF Clear

Monday, January 26, 2009

Three Denver Cyclones in a Row & The Life and Death of Tropical Cyclone Dominic

You are going to hear the word "cyclone" an awful lot in this blog entry.

For the past three days in a row, we have had a Denver Cyclone form over the metro area. I'm not going to get too into the formation process of this mesoscale phenomena but with soutwesterly winds aloft and southeasterly winds at the surface, the air tends to back and turn south along the foothills. Check out this radar image below.



The cyclone gave us some mild upslope flow which kept the low clouds in again today. Higher clouds moving over the area continued to seed the deck and give us some nice bursts of snow in bands. I got about 1.5" at my apartment over the course of the day.

Currently in the tropics:





10S Dominic - The storm that formed only yesterday has made landfall on the northwest coast of Australia today. Winds didn't top out much higher than 50kts, so it wasn't too powerful. It was moving fast enough that hopefully it didn't cause any flooding concerns either.





98P Invest - This area is expected to form into a tropical cyclone.






Denver radar and tropical satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images. Annotations are made by the author of this blog. Tropical cyclone tracking information from Navy/NRL Tropical Cyclone Page. Additional satellite imagery from JTWC.

NOTE: If you've reached this page due to a search result, the most current tropical information can be found in the latest post and not necessarily the post you are reading. Visit http://blog.bigskyconvection.com/ for the most recent post.


Dann.
Currently at Denver (Hampden Heights), Colorado: 6ºF Cloudy with flurries.

January 22nd Sunset in Denver & Dominic

It's cold and snowy here today in Denver. The most interesting that happened was watching a very shallow Denver Cyclone swirl the low clouds around. Meanwhile, Verne Carlson was above the low clouds enjoying the sun. Seems unfair!

The snow began on Friday and has only given us a dusting over the last few days. It is definitely much colder than it has been. Thursday (the 22nd) was our last real nice day and I enjoyed the evening at Washington Park with a couple of friends. Here are a few photos from that evening.








Currently in the tropics:

The area of disturbed weather I mentioned yesterday has in fact become at tropical cyclone off of the northwest coast of Australia.

10S Dominic






Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images. Annotations are made by the author of this blog. Tropical cyclone tracking information from Navy/NRL Tropical Cyclone Page. Additional satellite imagery from JTWC.

NOTE: If you've reached this page due to a search result, the most current tropical information can be found in the latest post and not necessarily the post you are reading. Visit http://blog.bigskyconvection.com/ for the most recent post.


Dann.
Currently at Denver (Hampden Heights), Colorado: 13ºF, Cloudy with flurries. Winds light, north.

Saturday, January 24, 2009

January 21st Sunset in Denver

Apparently it's wave-cloud chase season here in Denver! Enjoy.







We've had a slight change in the weather here. Yesterday, it actually snowed! We didn't get much ... but it was enough to take the edge off of the 77ºF earlier this week. It is only January after all.

We're definitely seeing a more active pattern now. The massive ridge has broken down in the west and shortwave after shortwave ought to bring some good snow to the west slope here in Colorado. Some of the longer model runs are hinting at the opening of the Gulf next weekend. Severe weather in the future?


In The Tropics:

No active systems. However, there are a few areas of note, especially 90S Invest which looks to be cyclonic already. I wouldn't be surprised to see it named before making landfall in Australia tomorrow.



Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images. Annotations are made by the author of this blog. Tropical cyclone tracking information from Navy/NRL Tropical Cyclone Page.

NOTE: If you've reached this page due to a search result, the most current tropical information can be found in the latest post and not necessarily the post you are reading. Visit http://blog.bigskyconvection.com/ for the most recent post.


Dann.
Currently at Denver (Hampden Heights), Colorado: 27ºF, clear, winds N ~5kt.

Thursday, January 22, 2009

Seasonal

It seems the last two winters in Denver could best be known only as "sunset season". We've been pretty dry this winter, same as last, and the setups have provided many wave cloud sunset opportunities. So, in this off-season for severe weather, there isn't much for a meteorologist like me to point my stick at.

This isn't the off-season everywhere, however. You just have to look south of the equator. If you've been frequenting this blog recently, you'll notice a lot of attention paid to the Southern Hemisphere Tropical Cyclone Season. I found a great map on Wikipedia that shows the distribution of tropical cyclones across the globe. You'll want to click on this image for a much larger version.




Current tropical activity.

09S Fanele - The JTWC has issued their final advisory for this storm as it continues to drift to the south and east, into cooler waters.






Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images. Annotations are made by the author of this blog. Tropical cyclone tracking information from Navy/NRL Tropical Cyclone Page.

NOTE: If you've reached this page due to a search result, the most current tropical information can be found in the latest post and not necessarily the post you are reading. Visit http://blog.bigskyconvection.com/ for the most recent post.


On the home front here in Denver, it didn't get quite as warm today. A few locales tipped 70ºF, but most hung around in the upper 60's. Driving into work this morning, I marveled at virga coming out of the standing wave cloud. A friend just told me he got a brief shower in Highlands Ranch today. There was considerably more moisture at the surface today, so I suppose that was possible.

Big changes are coming though ... snow and freezing rain wiped out the stagnant inversion in Salt Lake today. Parts of Montana are under winter storm warning. I see the possibility of snow here tomorrow and we, I almost can't believe this, may have enough moisture for some!

Dann.
Currently at Denver (Hampden Heights), Colorado: 45ºF BKN (high), wind: S ~10kt

Wednesday, January 21, 2009

One Hundred Eight Degrees

HEATWAVE!


... okay, so maybe not that type of heat wave, but it was very, very warm here along the Front Range today. Temperatures had been slowly climbing day after day for the past few. The air mass, not moving much in that time period, had only a limited amount of moisture work with. With continued downsloping winds heating the air, the moisture mixed out until it was bone dry.

Well, this trend continued into today. It was easy to see from the sounding the sounding this morning that temperatures would easily climb above 20ºC. And, well, today didn't disappoint. Sounds like it's time for a ... temperature roundup!

Let's start with official reporting stations!
72º KBJC - Broomfield/Jeffco (now Rocky Mountain Metropolitan Airport)
71º KDEN - Denver International Airport (official records taken for Denver here)
70º KBKF - Buckley Air National Guard Base
69º KAPA - Centennial Airport

UDFCD Mesonet stations:
77º - Diamond Hill (Downtown Denver)
74º - Brighton
73º - Castle Rock
73º - Highlands Ranch
73º - Quincy Reservoir
72º - Urban Farm (Stapleton)
71º - Aurora Town Hall
70º - Aurora Reservoir
70º - Pump Station 3 (Aurora)
69º - Brighton North
68º - Louisville

The 71ºF at DIA marks a record high temperature for this day.

Did I say dry? Check out this METAR from KBJC earlier today:

KBJC 212055Z 06022G37KT 70SM FEW200 22/M38 A3001 =

Okay, so that's 22C/-38C which gives us a 108ºF dewpoint depression. I guess you take an atmosphere with 4% humidity and push 20kt downslope into it, and suddenly you're down to 1%RH. We spoke about a 96ºF Td depression a month or two ago. Even that was amazing. I really don't know what to say know. All I know is my skin itches, and my eyes and nostrils are on fire.

I've been pretty weatharoused all day long needless to say. And the sunset, oh! ... the sunset. I haven't even had time to look at my photos yet. No time tonight, I guess. Though dry, we did get some mid-level moisture late and a beautiful wave cloud set up. I'll try and include those soon.

Things have calmed down significantly in the tropics. I haven't been able to find any good reports from the impact of Fanele, but found this beautiful image of Fanele before she made landfall yesterday:


Image from Nasa's Earth Observatory.


Currently:

09S Fanele - The storm has emerged on the southeast coast of Madagascar and will continue to weaken as it moves to the south and east.






There are a couple other ares of interest at the moment, but really nothing too interesting.

Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images. Annotations are made by the author of this blog. Tropical cyclone tracking information from Navy/NRL Tropical Cyclone Page.

NOTE: If you've reached this page due to a search result, the most current tropical information can be found in the latest post and not necessarily the post you are reading. Visit http://blog.bigskyconvection.com/ for the most recent post.


Dann.
Currently at Denver (Hampden Heights), Colorado: 41ºF BKN (high)

Tuesday, January 20, 2009

Fanele Strikes Madagascar, Colorado Heat & Dust Storm

Tropical Cyclone Fanele experienced rapid intensification in the Mozambique Channel over the past 24 hours, looping and striking the Madagascar Coast a little after 1Z on the 21st. While the area impacted isn't densely populated, two cities did bear the brunt of this storm's left front quadrant. The communities of Belo-Sur-Mer and the more densely populated Morandava to the north endured 100kt (115mph) winds as it came on shore. Unfortunately, it should be noted that most of the housing exits at an elevation below 20ft above-sea-level.

09S Fanele


*



08S Eric - Now no longer sideswiping the east coast of Madagascar, Eric is heading off to the south and losing steam. The JTWC is issued its final advisory on the storm.


*

Only two other areas being watched at the moment, one in the southern Indian Ocean and the other in the Southwest Pacific. 97S is remarkably close to the equator. (Due to Coriolis, it is hard to find tropical cyclone development in close proximity to the equator).



Satellite imagery used with permission; courtesy of IPS Meteostar Inc. Click for larger images. Annotations are made by the author of this blog. Tropical cyclone tracking information from Navy/NRL Tropical Cyclone Page. *Additional satellite imagery from JTWC

NOTE: If you've reached this page due to a search result, the most current tropical information can be found in the latest post and not necessarily the post you are reading. Visit http://blog.bigskyconvection.com/ for the most recent post.


Finally, what a day we had here in Denver! While official reporting stations only topped out in the upper 60's, several UDFDC mesonet stations eclipsed the 70ºF mark ... in January! We should expect to see this again tomorrow ... and maybe Thursday as well. Sounds like a good day to be outside.

Yesterday (January 19th), intense north-northeasterly winds scoured dust off the plains as seen in the satellite photo below. This dust storm caused a multi-vehicle pileup that claimed the lives of two.

http://www.denverpost.com/breakingnews/ci_11491639


Dann.