WINTER 2010-2011

[Joosanova]

Hey guys,

I wanted to start this thread specifically JUST FOR the upcoming winter season which has been touted to be significant in many aspects and thus I would like all relevant weather info and posts to be directed here instead of the regular weather forum.

I as the resident Met will be posting all necessary weather info pertinent to the coming winter season here in this thread and NOT in the other weather thread.

This includes updates on impending storms ( Wind, Rain, Snow ) of SIGNIFICANT nature as well as necessary Advisories, Watches and Warnings.

To the Mod's and Admins. Please delete this thread no earlier than April 7th 2011.

I will be posting here as much as deemed necessary or as warranted given conditions.

Additionally I will be posting more often ( multiple times a day ) as the season becomes more active or if severe or dangerous conditions are forecast or imminent.

[Bond James Bond]

Sooo . . . when do we get snow? I'm getting impatient.

[Bond James Bond]

Oh yeah - and I DEMAND a white Christmas. Please deliver. Thank you, and have a nice day.

[Joosanova]

So, as it stands now.... we are looking forward to our first " storm " of the season this weekend.

Latest MODIS guidance including the 4km and 12km GFS as well as the RUC shows a very strong 500mb Jet aimed directly at the Pac Nw for this weekend.

There are 3 systems forecast to impact us, the first 2 will be the typical run of the mill systems giving us light rain and cool temps HOWEVER.....

The 3rd system is pegged to come in around the early to late Saturday night time frame and throw us a bunch of rain, some of it heavy, specifically around the south and west end of the Olympic mountains. The EURO and GEM models show precipitable water rates for the 36 hr time frame of Saturday afternoon to Sunday evening in excess of 3 inches of rain, so needless to say that Saturday night and most of Sunday will be VERY WET!!!!

In addition to the rain, the winds will also pick up and this will be due to the enhanced jet stream and aided by a very strong sub 961mb low swinging offshore ( as of the latest model runs it would appear that the monster low for Saturday/Sunday is now pegged to be around 951-948mb which would equivalent to a weak CAT-2 hurricane ) thankfully this LOW will remain offshore and not make landfall anywhere near us otherwise we would be looking at a MAJOR WINDSTORM!!!

Thus I would expect winds along the coast to be in the 35-45mph with a few gust above 60 mph.

Winds in the N. interior would be in the similar range maybe a hair or two weaker.

Here in the Puget Sound basin winds will be the garden variety of 20-30 mph with a few gusts to 40 possible.

Saturday night and Sunday morning are going to be miserable weather wise, so go get some firewood and enjoy the weather this coming weekend.

We start to dry out Sunday night and by Monday morning and onward we will be post frontal and just have some lingering showers although temps will be a bit cool.

And lastly, anyone planning to travel over the mountains this weekend should do so before Saturday or after Sunday night as snow levels will be PLUNGING down to around 3500 feet, so those of you going across the passes ( especially Steven's ) should be prepared for heavy snow and freezing temps. Snoqualmie should be OK but the snow level could briefly come down below Snoqualmie but Steven's would be the worse pass as far as snowfall is considered.

Have a safe weekend everyone.

[Joosanova]

Originally Posted by Bond James Bond

Oh yeah - and I DEMAND a white Christmas. Please deliver. Thank you, and have a nice day.

Well BOND, if we manage a white x-mas this year it will be the 3rd white x-mas in 4 years!!!

You may just get your wish w/o having to demand it.

[Joosanova]

Originally Posted by Bond James Bond

Sooo . . . when do we get snow? I'm getting impatient.

The Mountains will be getting snow this weekend, see my discussion above

[Joosanova]

The 34km MM5 just came out and it shows up to a FOOT of BRAND NEW snow for the 24 hr period between Sunday morning 9am and Monday morning 9am.

SWEET!!!!!

[CrazyAboutCities]

What about Thanksgiving holiday?

[Joosanova]

Originally Posted by CrazyAboutCities

What about Thanksgiving holiday?

Cloudy, with periods of turkey and gravy followed by a prolonged period of sleepiness and finally a 100% chance of consumer madness the following Friday!!!

[Bond James Bond]

Originally Posted by Joosanova

Cloudy, with periods of turkey and gravy followed by a prolonged period of sleepiness and finally a 100% chance of consumer madness the following Friday!!!

+1

[Joosanova]

ARCTIC intrusion possible late next week!!!!

I will posting an in-depth analysis of a possible MAJOR pattern change to a colder and POSSIBLY snowier solution.

Check back in about 2 hours or so for all the info.

[WESTSEATTLEGUY]

just in time for the week of thanksgiving???

[Joosanova]

Ok, here is the discussion related to a " POSSIBLE " arctic air intrusion late next week.

First let me start by categorizing the levels I use to implement the likelihood of any such winter pattern coming to fruition.

Possible translates to a 5-20% of occurring
Likely relates to a 25-60% of occurring
Imminent translates to a 61-99% of occurring

As it stands right now, it's " POSSIBLE " we could be heading into a pattern change that would allow for some VERY cold temps and possible widespread snow event.

PLEASE keep in mind that the information to follow is in it's infancy and ANYTHING can change.

Over the last 5 days the EURO, GFS and ECWMF have all showed a somewhat cooler regime for the week leading up and beyond thanksgiving.

Today the same 3 models were STILL showing this same possible scenario but NOW the Composite and Ensemble means models are ALSO showing this scenario.

The event being showed by all these models is eerily similar to a pattern that slammed the Pacific NW in late November 1949 in which BOTH PDX ( Portland ) and KSEA ( Seattle ) recorded their second lowest all time daytime highs ( PDX recorded a daytime high during the height of the event of ONLY 11 Degrees and Seattle recorded a high of only 9 degrees and resulted in Seattle receiving it's 3rd most 24 hour snowfall of 23.3 inches.

The current pattern being showed would result in an area of high pressure building over the Pac NW and retrograding westward throughout time and setting up shop somewhere around 145-150W which for us would be the " SWEET SPOT " for cold and snow.

After the high reaches it final placement, the jet stream would arc up and over the Arctic Circle and drag down some VERY, VERY cold air for this time of year and allow for that cold air to PLUNGE down into our region and because the composite models are showing 500mb heights below 522dM as well as 850mb temps around -12 to -17C we could be looking at daytime temps during the event barely getting above 20 degrees Fahrenheit.

Not only that but the models also show embedded shortwaves diving down along the coast line giving us shots at snow about every 18-24 hrs.

This scenario is by NO MEANS set in stone but as of today the " event " is only 7 days out and well within the " Believable " range for those of us who follow these types of winter patterns.

Will it happen?

Hard to say but given the strength of the current La Nina and the fact that the SST's of the equatorial Pacific are the coldest they have EVER BEEN, it does appear that this winter could be as harsh or slightly worse than the winter of 1949-1950.

I will be updating the possibility of the event in the medium time range and additionally if said event does occur it would last quite awhile being that once the cold air arrives the models show the cold air staying in place possibly up to 2 WEEKS>

If you guys have any questions feel free to ask, otherwise stay tuned and I will keep you guys informed as this possibility gets closer to us.

[guinessbeer55]

When will the the major tv weather channels put this in their extended forecast's?

[Bond James Bond]

Oh cool! I want snow 3 or 4 days before Thanksgiving so I can have a 5 or 6 day weekend!

[Bond James Bond]

Oops, I take that back. Looking at my calendar, if it snowed a week from now that would still be a week before Thanksgiving.

Well, maybe it would snow late next week and I could get 2 4-day weekends in a row!



BTW Moose, any indication on how long this system might last?

[Joosanova]

Originally Posted by guinessbeer55

When will the the major tv weather channels put this in their extended forecast's?

Well given the raging amount of pessimism amongst all the local networks I would expect the following from all the networks.

KOMO4- maybe 3 or 4 days out

KIRO7- maybe 2 days out

Q13- who the hell cares, those guys suck

and

KING5- they will show it after it has already happened.

[Joosanova]

Originally Posted by Bond James Bond

Oops, I take that back. Looking at my calendar, if it snowed a week from now that would still be a week before Thanksgiving.

Well, maybe it would snow late next week and I could get 2 4-day weekends in a row!



BTW Moose, any indication on how long this system might last?

" I will be updating the possibility of the event in the medium time range and additionally if said event does occur it would last quite awhile being that once the cold air arrives the models show the cold air staying in place possibly up to 2 WEEKS "

[guinessbeer55]

haha!!! sounds about right!

[Bond James Bond]

Originally Posted by Joosanova

" I will be updating the possibility of the event in the medium time range and additionally if said event does occur it would last quite awhile being that once the cold air arrives the models show the cold air staying in place possibly up to 2 WEEKS "

Oops, sorry missed that.

Two weeks!! YEAH!! I want 2 weeks of snow!!!!