Vacation Time II

March 30, 2010

Looks like the comments shut off after 10 days of no posting.  Sorry about that.  It should be working again.  I’ve been checking on email/blog every 3 days or so and just now noticed the comments  stopped a couple days ago.

Yuck!  Looks like I’m not missing much back home.  Unusual late season snow in mountains and rainy/windy in the valleys.  I’ll be back on Friday.

Chief Meteorologist Mark Nelsen


Vacation Time

March 18, 2010

I’m taking an unusually long vacation for TV people…two whole weeks beginning Friday.  I haven’t done that since late winter 2003.  Poor Rod Hill had to work 16 days in a row.  What a jerk I was eh?  I’ll be back on Friday, April 2nd.

Generally you don’t see TV people take long periods of time off at once.  That’s because viewers get used to seeing a certain person on at a certain time.  If you disappear for a month, a viewer that enjoys watching you wonders if you’re in rehab, trekking around the globe, or having a mental breakdown.    I’m always amazed that after just one week I get emails from viewers asking if I’ve been fired or what kind of illness I’ve contracted.

So please behave on the blog…I’ll leave comments on.  I’ll be quite far away in a warm place, but with occasional internet access.  If there are any issues I’ll just turn comments off until I get back.

We’ll see if the vacation curse strikes again.  Hopefully not a windstorm with gusts to 70 mph @ PDX!

Chief Meteorologist Mark Nelsen


Busy night, but dead weather

March 17, 2010

No nice picture tonight, since the weather is REALLY slow for about 3 more days.  High pressure is settling in and shifts east of the Cascades a bit tomorrow for light offshore flow.  That should give us about 5 degrees of warming combined with a warmer atmosphere overhead.

Friday will give us one gusty east wind day as high pressure settles into the Columbia Basin and Intermountain region.  I’m worried that could cap PDX’s high temperature close to 60 degrees, while the areas away from the gusty east wind pop up into the mid 60s.

I did some fairly serious  surgery on the 7 Day forecast tonight.   Probably more than day surgery, but not a total open-heart, days at the hospital sort of thing.  A trough swings overhead later Saturday quite a bit closer to us than indicated just 24 hours ago.  We get the ol’ warm season double whammy of strong onshore flow Saturday evening plus a much colder airmass above.  For example we go from +9 deg at 850mb early Saturday to -1 or -2 Sunday morning!  We’ll go from warm and sunny to chilly and showery in just one day.  Saturday’s forecast high is a real tough one.  Depends on the timing of the trough and marine push.  Could be 62 or could be 68, I’m leaning towards the cooler one.  Strong easterly wind in the Gorge early Saturday morning goes gusty westerly by evening…spring must be here!

After that just cool and showery off/on next week.  I’m headed out for a long vacation beginning Friday, so I’ll try to post a few thoughts tomorrow around 6pm before I go home.  Tonight’s 10pm newscast will be the last for me until Friday, April 2nd!

Chief Meteorologist Mark Nelsen


Report from Up North

March 15, 2010

Here is a posting on the Oregon Chapter AMS website by Phil Welke…known to most of us on here by HIO-Phil.  Some good info from the Pacific Northwest Weather Workshop a little over a week ago.  I’ve gone in the past and highly recommend it to anyone looking for a bit more in-depth weather information/discussion.  Topics cover just about everything related to our weather.

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Pacific Northwest Weather Workshop Report – March 5-6, 2010

I traveled up to Seattle this year for the Pacific Northwest Weather Workshop that was sponsored by the NWS, U of W, and the Puget Sound Chapter of the AMS, and was held on the NOAA campus in Seattle.

Friday March 5th:

For me, the highlights of the first session were the description and satellite photos of the Bering Sea Super Storm which resulted in Blizzard Warnings running for about 12 continuous hours in some areas across SE Alaska and the Aleutians. I believe the low peaked at about 955mb which is not unusually strong for the gulf. The record in the Bering Sea/Gulf of Alaska is about 913mb, according to the Alaska NWS staff that were present.

The other area that was interesting from a technical standpoint was the use of Thermal Wind Profiles from rawinsonde and NWS 88D Radar measurements of a developing baroclinic leaf to verify model forecast wind outputs before storm winds reach the shore. Something that should be able to be done with the Washington coastal radar when installed as well!

The second section included a presentation on the UCAR/COMET educational program that offers free online meteorological classes for those that are interested, as well as a variety of other online offerings. This looks like a good place for amateurs and possibly professional mets to improve their weather knowledge and forecast skills.  http://www.comet.ucar.edu/aboutus.htm

Another interesting presentation was on the Tumblebug fire and the effect a thermal trough had on it, first from increased east winds and then from the instability and low dew points induced as the thermal trough passed over it. One item that got a reaction in the room was the -5°F dew point measured at one point. Yes, a -5 dp in September, not during an arctic blast in January! Another area of fire weather that was interesting was the positive correlation between Downdraft CAPE (DCAPE) and fire growth.

Coastal status amounts/periods appear to be increasing over the last several decades in the Northwest.

The World Wide Lightning Location Network looks very cool:  http://www.wwlln.net/

Saturday March 6th:

The Howard Hanson Dam in Washington looks like a major disaster in the making. The Seattle NWS and local media are partnering to increase lead times for getting flood warnings out to cities and municipalities, in addition to the public. They have also modeled rainfall rate scenarios into their warning criteria.

The Coastal Radar is going to be awesome! It should be the most advanced radar in the country. Cliff Mass would not tell us where it will be sited, but did mention the final three locations. It looks like it will be close to the coast and will be able to scan from 0 degrees up over a very large area off and inland of the coast, which will give us a much better idea of storm structure and coast range precipitation. 0 degrees is basically straight out parallel to the ground, but of course the earth curves so that the beam rises in height as the earth curves away over distance. This is still much better than a 1 or 2 degree angle. Oklahoma NWS, which manages the radar installations, is being a bit difficult, as the local NWS is requesting that the radar be able to not only scan in a circular motion, but also up and down to read storm structure, and they don’t think it’s necessary. Cliff thinks it will be installed and operational sometime well-prior to January 1, 2012. And a big shoutout to Senator Cantwell for her efforts from Cliff.

An interesting observation from one presenter is that historic rainfall events in central California actually occur most often in La-Niña patterns and not El-Niños. In fact, the maximum event occurred during a La-Niña. One possibility is that the cold air and the corresponding baroclinic zone are pushed farther south into California, where they can be quite stable, resulting in long-term flooding rains.

There was a good presentation on the rain-snow line in mountains documenting and modeling how orographic forces push down the snow level on the windward side of mountains below what would be expected based on the free-air freezing level. This is partially due to adiabatic cooling as the air flow is pushed up over the mountain.

There was an interesting presentation on the challenges of Nowcasting and the instrumentation used for the 2010 winter Olympics by a Canadian met involved in the effort.

Jay Albrecht gave a presentation on his historical weather program. Definitely a very good effort and already used by others here at the Oregon AMS for historical weather research of station readings and weather charts. Jay has obviously put a tremendous amount of time into this and deserves applause from all of us.

George Miller gave a brief overview of the work he has done documenting Oregon tornados and gave a few examples of historical Oregon tornadoes. It was interesting to note that the word “Tornado” was not favored by professionals until the more recent past.

Regarding tornados, there were two presentations on recent Northwest tornados, the Northeast Oregon Mini-Supercell/Tornado and the Buckley-Enumclaw Washington Tornado. What was interesting about the NE Oregon event was that instability indexes were marginal at best due to morning cloud cover, but clearing aided by a dry slot moving over the area allowed the sun to heat the air mass into the corresponding dry air in a very brief period of time and generate the supercell. Regarding the Washington tornado, what came across to me was the difficulty in spotting the signature on weather radar. It could easily be missed on the screen. NWS Seattle was suggesting that, during times when there is a possibility of severe weather, one team member should be dedicated to watching the radar at all times.

Finally, the conference finished with a presentation on weather photography with great examples, of course. If you want to get good pictures, be prepared to be up at anytime of the day or night and pay attention to your weather resources, satellite, forecast, etc.

As for the format of the conference, the 15-minute time slots for presentations were right on the money, and the food and snacks were very good (Mark’s editor note:  did they have those good squishy chocolate chip cookies again??? I remember those from about 2 years ago).

Phil Welke
AMS Member


Great Mountain Snow

March 12, 2010

Photo by Richard Hallman - Mt. Hood Meadows

Now that looks like some fine skiing.  Mt. Hood Meadows sent this and a few other pictures in earlier today.

A chilly trough passing overhead this evening along with a solid band of heavy precipitation dragged the sticking snow level down to about 1,000 ft. briefly.  My friend up at 1,800′ on Larch Mt. had about 1/2″, I had a dusting on the deck at home (phoned in via mini-Mark).  And I think one of you here on the blog saw all snow in the air up at Council Crest.  The last band of showers is moving towards the north coast right now, then it looks real quiet after daybreak tomorrow.

I see low level moisture goes away tomorrow night through Monday night as our low level flow turns easterly or southeasterly.  That combined with a much warmer atmosphere holds the promise of a dramatic warming trend.  The reason it won’t get insanely warm (65-70) is all the cloud cover both Sunday and Monday.  We’re a little too close to systems traveling north along the coastline.

The 2nd half of next week will either be mostly sunny and mild (60-65 on the ECMWF) or mostly sunny and a bit cool (50s on the GFS).  For now we’re taking the cooler temps route with chilly high pressure at the surface coming down from the north.  00z GFS is quite cold again with 850mb temps below zero the entire period beyond Tuesday.

I spent a LOT of time staring at fonts and graphics today…so that’s it.  Have a good weekend!

Chief Meteorologist Mark Nelsen


Your Thoughts?

March 11, 2010

Do you see the 16x9 (wings) on your main home television nowdays? If you see us over the air or get HDTV/Digital from your provider you do. Vote below

Just for fun today, let me know what part of our weather graphics you see when you watch from home.

The reason I’m asking this is that I want to get a general idea of what people are seeing.  Up until about three years ago stations in our area were broadcasting in the original 4×3 “square” looking size.  That’s how it started in the 1950s.  Then stations began broadcasting in “widescreen” or the 16×9 format.   Most cable companies are not passing through the “whole picture” unless you get HD specifically or their “digital tier”.  Bascially they “cut-out” the middle part of the picture and pass it on to you.  Pardon my lack of knowledge about that, but I don’t get cable at home, just an antenna so I see the whole picture.   All local stations broadcast in the wide 16×9 format whether a station is broadcasting in HDTV or not.  KPTV is not yet broadcasting newscasts in HD.

What does this have to do with weather?  Well it’s directly related to what we do in the weather center.  When we make weather graphics, we have to keep anything important in that 4×3 area.  And just today while I was working on a new 7 Day forecast page I thought how nice it would be to use that whole space so each day’s weather would be larger.  But that’s not going to happen until the vast majority of viewers are watching the 16×9 wide view.    I suppose a good analogy is that TV programs probably didn’t make specific color references until most viewers had color TVs.

This is also the reason we have to stay in the main part of the view when working at the green wall.  If you watch the 4×3 format (cable) you may notice sometimes weather people drift in and out of the shot, or even stay half-in/half-out.  That means they aren’t paying attention to the wings and are out on the edges where on the widescreen viewers can see.

Really a rainy night out there, tomorrow looks only slightly better.


It Could Be Warmer

March 10, 2010

Remember this warm stretch of weather 5 years ago? 4 days at/above 70 in early March! Hard to beat that this time of year. Now it was 66 last Saturday, and next Monday looks warm too.  Between now and that time it looks very wet.  Nice baroclinic zone (cold front/warm front/occluded front) sits right over us from later tonight through Friday morning.  Tomorrow should be just plain wet all day.  Then more to showery weather Friday.  Weekend still looks much better with mainly dry weather Sunday and Monday.

Not a real insightful post, but I’m just coming off those sickie days answering emails, answering a phone call from a person starting a phone conversation with “what are your days off?” (strange…), and we have some much faster new computers which needed babysitting.

Chief Meteorologist Mark Nelsen


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