It is currently Nov 21, 2019 9:08 am 






Reply to topic  [ 4 posts ] 

Previous topic | Next topic 

  Print view

Offline 
 Post subject: Change in the Weather Pattern for the Week Ahead
Post Posted: Nov 2, 2017 8:05 am 
Oh my, Big Time poster!
Oh my, Big Time poster!
User avatar
Joined: Feb 19, 2007 5:52 pm
Posts: 3228
Location: Conifer Mountain
System skirted north of CO last night bringing cooler temps and low clouds to eastern CO, but it will remain sunny and breezy from the foothills west today. Temps will be overall cooler than yesterday, so closer to seasonal norms. Gusty westerly winds of 20-45 mph will be present at higher elevations most of the day.

On Friday, we will begin to see a large upper level pattern change take place over the U.S. The past week we have had a large upper ridge over Alaska and an upper trough over the eastern U.S. causing brisk northwest flow aloft over CO. On Friday, the upper level pattern will begin to change with a upper level trough developing along the West Coast and an upper ridge over the eastern U.S. This will put CO under a brisk southwest flow aloft for the next 7-10 days. It will also allow systems to move through the long wave upper trough along the West Coast and move out across CO, so we will have a more progressive weather pattern that will allow for moisture to move into CO, especially along and west of the Divide.

Friday will be warm and breezy across CO with temps well above average, and southwest winds of 25-50 mph in the mountains and foothills. The first in a series of Pacific systems will bring clouds and some mountain precip to CO on Saturday with snow level near 10,000 ft. Precip looks to remain mostly along and west of the Front Range Crest, so only a few showers possible in the foothills. Temps will be well above average on Saturday. The main bulk of this system will move over CO on Sunday, so more precip chances from the foothills west on Sunday, with cooler temps and snow level near 8000 ft. Only light precip is expected in the foothills, with heavier amounts farther west.

Next and stronger system will move into CO on Monday. Precip will move into western CO early in the day and gradually spread east to the Front Range Crest by afternoon with snow level near 8000 ft. Models differ a bit on timing and intensity, but will favor the ECMWF solution at this time which would bring precip into eastern CO Monday night into Tuesday as snow levels lower to near 6000 ft. ECMWF brings more than 0.50 inches of liquid while the GFS is much drier, but if ECMWF is correct, foothills could see decent snowfall Monday night into Tuesday afternoon next week above 6000 ft. Mountain areas could see a few feet of snow at higher elevations.

Models then diverge later next week as GFS brings another cooler system into CO Thursday into Friday with snow down to lower levels, while the ECMWF keeps CO dry late next week with near average temps. Will have to wait and see how this progresses, but the good news for CO is that with a more progressive weather pattern, the mountains will begin to receive much more snow and some precip will be possible across eastern CO.

We ended October with 15 inches of snow on Conifer Mountain, which is slightly above the average of 13 inches. We stand at 15.5 inches for the season now, slightly below the average of 16 inches through October. November is typically a rather dry month for much of CO, with 14 inches of snow on average on Conifer Mountain. The latest seasonal outlook from the Climate Prediction Center call for temps to be above average across CO November through January, and for precip to be above average across northwest CO, and near average elsewhere. From an ENSO standpoint, we are having weak La Nina conditions in the Pacific which are expected to persist through Winter and into Spring. These conditions typically bring abover average snowfall to the northern and central mountains, with below average snowfall across eastern CO, including our foothills as well as the southwest mountains. Expect stronger and more frequent downslope westerly winds this season, similar to last winter in our foothills, with a few cold air arctic outbreaks December through February. We will have to wait and see what upper level pattern become dominant this winter.

_________________
"Climatology is what you expect, Weather is what you get" - R. Heinlein.

"Sunshine is delicious, rain is refreshing, wind braces us up, snow is exhilarating; there is really no such thing as bad weather, only different kinds of good weather" - John Ruskin


Top
  Profile  
Reply with quote  
Offline 
 Post subject: Re: Change in the Weather Pattern for the Week Ahead
Post Posted: Nov 3, 2017 2:07 pm 
Oh my, Big Time poster!
Oh my, Big Time poster!
User avatar
Joined: Feb 19, 2007 5:52 pm
Posts: 3228
Location: Conifer Mountain
Warm and breezy day across the state as upper level flow has become southwesterly as upper level trough digs along the West Coast. Temps will be above average today statewide with no precip expected. Flow aloft will increase Friday night, so expect gusty southwest winds in the mountains and foothills tonight with speeds in the 25-50 mph range.

For the weekend, clouds will begin to move into western CO ahead of West Coast system and wind speeds will also increase across much of CO as strong southwest winds aloft will be over the state. Wind speeds in the foothills could be in the 30-60 mph range during the day on Saturday. Precip will move into northwest CO during the day on Saturday, but snow level will remain above 10,000 ft. Precip will persist Saturday night in the mountains as snow level lowers to near 8000 ft, with majority of precip remaining along and north of I-70 and west of the Front Range Crest. Precip will continue most of the day Sunday along and west of the Front Range Crest with snow level near 8000 ft. Foothills could see a few brief showers and blow off snow, but no accumulation expected. Precip should taper off in the mountains Sunday night and be done by Monday morning. Some mountain areas above 10,000 ft could see 6-18 inches of snow by Monday morning.

For next week, models not in very good agreement. They agree that a upper level trough will move across CO, but GFS is faster and farther north, while the ECMWF is slower and deeper with the upper trough. Thus, GFS brings some light snow to northern and central mountains Monday into Tuesday morning, while ECMWF brings snow to mountain areas Monday night then brings snow south across most of CO Tuesday into Wednesday morning. Snow amounts look good for the mountains with anotehr 6-12 inches, while foothill areas and eastern CO likely only to see 1-3 inches of snow. Snow level will be lower with snow level near 6000 ft Monday night lowering to near 4000-5000 ft on Tuesday into Wednesday morning.I am currently favoring the ECMWF solution.

Later next week, upper ridge moves over CO so expect dry and mild conditions Thursday into Friday. Weak system may bring some light precip to mountains and foothills Saturday, then dry and mild Sunday.

Upper pattern remains in tact the following week, so precip possible Monday into Tuesday, then again late in the week Friday into Saturday.

_________________
"Climatology is what you expect, Weather is what you get" - R. Heinlein.

"Sunshine is delicious, rain is refreshing, wind braces us up, snow is exhilarating; there is really no such thing as bad weather, only different kinds of good weather" - John Ruskin


Top
  Profile  
Reply with quote  
Offline 
 Post subject: Re: Change in the Weather Pattern for the Week Ahead
Post Posted: Nov 5, 2017 8:07 am 
Oh my, Big Time poster!
Oh my, Big Time poster!
User avatar
Joined: Feb 19, 2007 5:52 pm
Posts: 3228
Location: Conifer Mountain
Some lingering snow in the mountains this morning with snow level near 8000 ft, but overall a pretty typical Fall day across the state with temps near seasonal norms, and less wind than the past 2 days. Precip will lessen in the mountains during the day but some flurries will linger into tonight across higher terrain. Winter Storm Warning and Winter Weather Advisories are in effect across much of the mountains through Monday morning for 6-18 inches of snow, so travel across higher passes will include winter driving conditions.

For the week ahead, Monday should be pretty similar to Sunday, some lingering mountain flurries with snow level near 8000 ft, otherwise mostly dry across the state. Models now in better agreement with GFS leaning toward the ECMWF. A cold front is forecast to move south across eastern CO Monday night as upper level trough from the Pacific Northwest moves south over CO. Surface winds will become northeasterly and bring low clouds along with precip after about midnight to much of eastern CO from the Divide east. Snow level will initially be near 6000 ft Monday night lowering to 4000-5000 ft by Tuesday morning. Snow and low clouds will persist much of the day on Tuesday, but snow is expected to remain mostly light. Snow will continue through about 6 am Wednesday, then begin to clear through the day on Wednesday. Snow amounts across eastern CO are expected to remain on the light side, with generally 1-3 inches across much of the area, with perhaps up to 5 inches in favored areas of the foothills. Expect slick road conditions Tuesday morning, with melting during the day, then more slick conditions Tuesday night into Wednesday morning.

The remainder of next week looks dry and mild statewide with temps returning to seasonal norms Thursday into the weekend. A weak system may skirt CO Saturday and bring a chance for some precip over the mountains, but otherwise mostly dry statewide through Sunday. The next week also looks mostly dry and mild with a chance for some mountain precip on Tuesday.

_________________
"Climatology is what you expect, Weather is what you get" - R. Heinlein.

"Sunshine is delicious, rain is refreshing, wind braces us up, snow is exhilarating; there is really no such thing as bad weather, only different kinds of good weather" - John Ruskin


Top
  Profile  
Reply with quote  
Offline 
 Post subject: Re: Change in the Weather Pattern for the Week Ahead
Post Posted: Nov 6, 2017 7:32 am 
Oh my, Big Time poster!
Oh my, Big Time poster!
User avatar
Joined: Feb 19, 2007 5:52 pm
Posts: 3228
Location: Conifer Mountain
Quick update on incoming snow maker before I head to Seattle this morning. Models overall in good agreement on incoming system with snow spreading south from the WY border tonight. Snow should move south of the I-70 corridor between midnight and 3 am, with some banded heavier snowfall possible for the Tuesday morning commute, so expect a slower and slick commute Tuesday morning as snow level will be down to plains level by morning, thus slick roads at higher elevations and a mix of snow, slush and wet roads for the Metro area. Light snow will likely continue intermittently most of the day on Tuesday with minimal additional accumulation, and roads should warm enough to melt most of the snow. Models suggest another band of snow will move across the area Tuesday evening, so roads may become slick again Tuesday evening into Wednesday morning. Snow should dissipate after midnight Tuesday night with clearing on Wednesday.

For snow amounts, most models are in the 0.10 to 0.5 inch range of liquid equivalent for the foothills, so we will likely see a range from 2-5 inches for most foothills areas, with highest amounts north of I-70 and in favored locations. For the Urban Corridor, likely to see 1-3 inches with heaviest amounts on the south and west side of the Metro area, and generally less than an inch across the eastern plains.

Rest of the week continues to look dry with temps returning to near average values Wednesday through Friday. Weak system may bring some mountain showers Saturday, otherwise continued dry and mild into next week, with another weak system Tuesday next week with mostly mountain precip.

_________________
"Climatology is what you expect, Weather is what you get" - R. Heinlein.

"Sunshine is delicious, rain is refreshing, wind braces us up, snow is exhilarating; there is really no such thing as bad weather, only different kinds of good weather" - John Ruskin


Top
  Profile  
Reply with quote  
Display posts from previous:  Sort by  
Reply to topic  [ 4 posts ] 

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:

Who is online

In total there are 13 users online :: 0 registered, 0 hidden and 13 guests (based on users active over the past 60 minutes)
Most users ever online was 2823 on Mar 26, 2012 6:26 pm

Users browsing this forum: No registered users and 13 guests





Powered by phpBB © 2000-2012 phpBB Group

This website copyright © 1994-2019 by
Pinecam.com is a member of the Platte Canyon Area Chamber of Commerce