Mountain West Discussion

[Front Ranger]

Back to boring/dry for at least a bit now it appears.

[Black Hole]

Should see showers and thunderstorms pick up tonight and tomorrow here. Rain will switch to snow for a slushy inch or two on Sunday. After that we quickly rebound to warm weather again. 

[epiceast]

Models continue to water down the storm.

[Kayla]

Still lots of questions for the Saturday night/Sunday system for here. Euro has been most consistent showing about 2-4" of snowfall for several days now while the GFS/GEM/NAM have been all over the place. 12z GEM was the most bullish this morning showing about 8-10" of snowfall in the same period. 

 

2-4" seems like a safe forecast at this point but still a couple more runs to fine tune things. Either way, it's nice to see the pattern turning much more active after a very benign March.

[Kayla]

Looks like the NWS is onboard. They just issued a Winter Storm Watch for my area and as of right now think 6-12" for elevations at or above 5,000' (I'm at 5,350').

 

Seems pretty bullish to me but maybe the GEM is onto something...

[epiceast]

Looks like the NWS is onboard. They just issued a Winter Storm Watch for my area and as of right now think 6-12" for elevations at or above 5,000' (I'm at 5,350').

 

Seems pretty bullish to me but maybe the GEM is onto something...

 

Climo wins. The ULL always forms 100 miles south or east of having significant effects on Missoula, it can only effect locations on continental divide or east. It was nice seeing NAM/GFS/GEM agree for  half a foot here in town for about 24 hours though, and 3' in the Rattlesnake/Mission mountains. 

[epiceast]

http://atmos.washington.edu/wrfrt/data/timeindep/images_d3/msnow24.24.0000.gifSorry Kayla. 

[Kayla]

http://atmos.washington.edu/wrfrt/data/timeindep/images_d3/msnow24.24.0000.gifSorry Kayla. 

 

???? 

[epiceast]

???? 

The shortwave will not hit you, and this map also implies that the ULL will not be able to pull the moisture back into your valley, so you will end up with like an inch or two. If you look at the radar trends, it looks like the old solutions(favoring GNP, Missoula, Great falls and not Bozeman or Billings) were right because the returns are moving north of the blue mountains into the Columbia basin and the Palouse.

[Kayla]

The shortwave will not hit you, and this map also implies that the ULL will not be able to pull the moisture back into your valley, so you will end up with like an inch or two. If you look at the radar trends, it looks like the old solutions(favoring GNP, Missoula, Great falls and not Bozeman or Billings) were right because the returns are moving north of the blue mountains into the Columbia basin and the Palouse.

 

Wasn't aware that this was a competition. That map still shows about 3-5" for me and the WRF has performed horribly this year. The Euro has shown the most consistency with the ULL which still gives my area 3-6" which seems like a good forecast at this point. This was never looking like a major event for this area but rather a moderate spring storm.

[epiceast]

Wasn't aware that this was a competition. That map still shows about 3-5" for me and the WRF has performed horribly this year. The Euro has shown the most consistency with the ULL which still gives my area 3-6" which seems like a good forecast at this point. This was never looking like a major event for this area but rather a moderate spring storm.

It's not, but I don't think we ever get a lot of snow out of the same snowstorm(think Seattle & Portland). I was just excited about getting a lot of snow for going last day of resort skiing tomorrow. Probably will end up getting sorting in town too (trace-6"). The boundary is very sharp with this one, at least for valleys, I don't think a lot of people will see 3-6" east of the divid it will be either an inch or a foot. 

[Kayla]

It's not, but I don't think we ever get a lot of snow out of the same snowstorm(think Seattle & Portland). I was just excited about getting a lot of snow for going last day of resort skiing tomorrow. Probably will end up getting sorting in town too (trace-6"). The boundary is very sharp with this one, at least for valleys, I don't think a lot of people will see 3-6" east of the divid it will be either an inch or a foot. 

 

There is a stark difference between Bozeman and Missoula as the two cities sit in two completely different climates and are ~1,600' in elevation apart. Bozeman sits in a cold/dry continental climate whereas Missoula has a cold semi-arid climate. Bozeman is quite unique in that it receives plentiful moisture year-around for a continental climate and averages 86" snowfall to Missoula's 45" annually.

 

And an inch to a foot?? That's quite the range!  

[epiceast]

There is a stark difference between Bozeman and Missoula as the two cities sit in two completely different climates and are ~1,600' in elevation apart. Bozeman sits in a cold/dry continental climate whereas Missoula has a cold semi-arid climate. Bozeman is quite unique in that it receives plentiful moisture year-around for a continental climate and averages 86" snowfall to Missoula's 45" annually.

 

And an inch to a foot?? That's quite the range!  

Yes I know that my climate doesn't deliver as much snow as most cities in Montana. Only plains & cities further south in Bitterroot valley get less. My point was that you would need the low to take a very unusual track to give a significant snowstorm to both Bozeman & Missoula. And yeah, look at those gradients on the silly map.

[epiceast]

Starting to get worried this storm will go north of everyone and hit US/CA border and MT-hiline. It's certainly not encouraging to see that band go north of Spokane and not pivot.

[ShawniganLake]

Starting to get worried this storm will go north of everyone and hit US/CA border and MT-hiline. It's certainly not encouraging to see that band go north of Spokane and not pivot.

NWS is forecasting 1/2 -1" for Missoula. Were you expecting them to bust badly?

[epiceast]

NWS is forecasting 1/2 -1" for Missoula. Were you expecting them to bust badly?

The models are moving it 100 miles in whatever direction run to run.

[Kayla]

Starting to get worried this storm will go north of everyone and hit US/CA border and MT-hiline. It's certainly not encouraging to see that band go north of Spokane and not pivot.

 

Current low placement is pretty much exactly as progged. Currently crossing through eastern ID moving NE. I think the biggest concern this evening is a lack in cold source. It appears that the low isn't pulling as much cold air south that was earlier modeled. If this trend continues we may begin to lose out on the moisture before the cold air arrives.

 

With that all said, the 18z GFS/NAM and the 22z HRRR looked pretty promising for tonight through tomorrow morning.

[epiceast]

Current low placement is pretty much exactly as progged. Currently crossing through eastern ID moving NE. I think the biggest concern this evening is a lack in cold source. It appears that the low isn't pulling as much cold air south that was earlier modeled. If this trend continues we may begin to lose out on the moisture before the cold air arrives.

 

With that all said, the 18z GFS/NAM and the 22z HRRR looked pretty promising for tonight through tomorrow morning.

Accumulating snow levels were a touch above 4000' with the last shower. Got down to 37 here, probably had flakes in the air well below 3.5k'

[Kayla]

Accumulating snow levels were a touch above 4000' with the last shower. Got down to 37 here, probably had flakes in the air well below 3.5k'

 

Yeah I see Butte just switched over which spells good news for me here once the precip arrives in the next hour or so.

 

Looks like your best bet at at some accumulations is with the wrap around moisture later tonight.

[epiceast]

Yeah I see Butte just switched over which spells good news for me here once the precip arrives in the next hour or so.

 

Looks like your best bet at at some accumulations is with the wrap around moisture later tonight.

Flow is becoming more northerly, shower coverage is increasing again. Shouldn't take that much more to bring the snow level to the valley floor here.

[Kayla]

Heavy, heavy wet sticking snow has begun here. Heaviest snow I've seen since we moved here in mid January.

 

Temp went from 40º down to 32º within about 2 minutes. Gotta love living in the Northern Rockies!

[SilverFallsAndrew]

Official OBS as of 10pm pacific....

 

Bozeman Cloudy and 37

Missoula  Cloudy and 38

 

Both lose?

[Black Hole]

I had .97" of rain before it switched to snow and clogged my gauge up. About 2" of accumulation so far.

 

A healthy lake effect band is kicking up so may see a few more inches by morning.

[SilverFallsAndrew]

I had .97" of rain before it switched to snow and clogged my gauge up. About 2" of accumulation so far.

 

A healthy lake effect band is kicking up so may see a few more inches by morning.

 

How common is April snow there?

[epiceast]

Official OBS as of 10pm pacific....

 

Bozeman Cloudy and 37

Missoula  Cloudy and 38

 

Both lose?

36 rain dew point 34 here now! One heavy shower and it's all grass accumulating snow.

[Kayla]

Hasn't stopped snowing since it began last night around 9pm. Looks like about 4-6" so far and still coming down moderately. Hard to believe it's April 9th and we're about to XC ski from our house and up into the hills. Currently 27º. 

[Kayla]

Official OBS as of 10pm pacific....

 

Bozeman Cloudy and 37

Missoula  Cloudy and 38

 

Both lose?

 

The Bozeman Airport is actually in a different town (Belgrade) and sits in the center part of the valley at about 4-500ft lower than most of the actual city of Bozeman. It's definitely not a very accurate representative of what's actually happening in the city. 

 

MSU is used for most of the official city readings and can be viewed here. http://orsl.eps.montana.edu/weather/

[SilverFallsAndrew]

The Bozeman Airport is actually in a different town (Belgrade) and sits in the center part of the valley at about 4-500ft lower than most of the actual city of Bozeman. It's definitely not a very accurate representative of what's actually happening in the city.

 

MSU is used for most of the official city readings and can be viewed here. http://orsl.eps.montana.edu/weather/

Okay well that makes sense!

[epiceast]

Great falls did okay, complete and total bust for everybody else(including snowbowl, only 6" . Missoula got about .05" of qpf in snow form we'll see if there was an accumulation at the airport, there isn't one here right now on southeast end of town.

[Black Hole]

How common is April snow there?

Most years there is at least a little bit of something, so not really unusual. Looking ahead this was probably the last snow storm of the season though. 

 

There was another 2" or so overnight. 

[Scott]

March was hot in Mountain West 

 

It was our hottest March in Craig, Colorado:

 

http://www.summitpost.org/images/original/997072.JPG

 

We did manage 3 days of 0F or below, but it was a very remarkably warm month.  The 75F on March 18 was the warmest we have ever gotten that early in the year.   The snow also completely melted from yard earlier than any other date.   I was in Jamaica part of the time, so I don't know the exact date it melted, but when we got back on the 26th, there was no snow at all in the yard.  The next earliest date that the snow has completely melted from the yard was March 31st.

 

We also had four mornings at the official station where it didn't drop below freezing, which is extremely unusual.  38F on the 22nd was also the warmest March low on record at the official weather station.  

[Kayla]

Had very heavy snow here last night that quickly dropped 1-2" of snow as a upper level disturbance moved through. Definitely been an active start to the month!

 

Beautiful sunrise this morning after a low of 21º and after the freezing fog dissipated.

 

[Black Hole]

This was the morning after my snow event a few days ago. All gone now!

[Front Ranger]

No sign of any precip for at least the next week here.  <_>

[Black Hole]

A couple of interesting graphs of the Great Salt Lake level here in Utah. Levels have declined each year for the past few with drought conditions. This year finally provided a well above normal winter and water levels have surged. Hopefully the lake will rise a few more feet given all the snow in the mountains.

[epiceast]

A couple of interesting graphs of the Great Salt Lake level here in Utah. Levels have declined each year for the past few with drought conditions. This year finally provided a well above normal winter and water levels have surged. Hopefully the lake will rise a few more feet given all the snow in the mountains.

Does the Salt Lake level affect anything? I feel like it shouldn't... because it's a salty lake.

[SilverFallsAndrew]

Does the Salt Lake level affect anything? I feel like it shouldn't... because it's a salty lake.

Well in 1983 it flooded.

[Black Hole]

Does the Salt Lake level affect anything? I feel like it shouldn't... because it's a salty lake.

The Salt Lake is a part of the local economy. Lots of boaters and salt shrimp fishing. There are parks around and on the lake that do better when the lake is higher. The lake plays a roll in precipitation around here and is responsible on average for 10% of winter precipitation. If the lake is too low then dust blows off of it and causes air quality issues. The lake keeps temperatures somewhat more moderate on average. 

 

Finally, it just looks better when it is full. That's what I know offhand. 

[Scott]

 The lake plays a roll in precipitation around here and is responsible on average for 10% of winter precipitation. 

 

 

I have always thought that this is the biggest factor.  Since the lake is 1/3 of the size it was in the 1980's, I wonder what lake level the 10% is based on?   The lake definitely has a smaller effect the smaller the surface area is.  

 

With a growing population in an already arid area, a 10% loss in average precipitation/snowpack  could have a huge effect on the area.

 

Snowfall has decreased greatly in the last decade in the Salt Lake City area; more so than the surrounding regions.  Lower lake levels definitely contributed some of this, but I wonder how much?

[Black Hole]

I have always thought that this is the biggest factor.  Since the lake is 1/3 of the size it was in the 1980's, I wonder what lake level the 10% is based on?   The lake definitely has a smaller effect the smaller the surface area is.  

 

With a growing population in an already arid area, a 10% loss in average precipitation/snowpack  could have a huge effect on the area.

 

Snowfall has decreased greatly in the last decade in the Salt Lake City area; more so than the surrounding regions.  Lower lake levels definitely contributed some of this, but I wonder how much?

One of my professors at the U of U has done some studies on the factors that affect lake effect, I will try and find those papers as they may interest you. I recall that he found that pattern is much more important than lake size, but even so, its clear that the smaller lake means less intense lake effect at the least, and we've seen that the last few years.

 

I don't know what period the 10% is based on off hand, but I would also be interesting in seeing how much as well. 

[Kayla]

Complicated forecast over the next 48 hours here. Strong cold front moves through this evening bringing heavy rain changing over to snow. The big question is when. NWS seems to think snow levels will not drop until most of the moisture moves through with a dusting to 1" at best. Most of the models show a switch over to snow by 10pm with accumulating snow beginning around 2am.

 

I think we'll see heavy enough precip rates to get 1-3" of snowfall tonight/tomorrow morning.

 

Another shortwave moves through tomorrow night which should be all snow and could drop another 2-4" of snowfall. Active April continues.

[Black Hole]

The same cold front will pass through here but it looks dry, big temperature drop though. 

[Front Ranger]

After a brief respite at the beginning of the month, we're back to May-like temps and bone dry weather here. Been an exceptionally boring last 90 days.

[epiceast]

I have always thought that this is the biggest factor.  Since the lake is 1/3 of the size it was in the 1980's, I wonder what lake level the 10% is based on?   The lake definitely has a smaller effect the smaller the surface area is.  

 

With a growing population in an already arid area, a 10% loss in average precipitation/snowpack  could have a huge effect on the area.

 

Snowfall has decreased greatly in the last decade in the Salt Lake City area; more so than the surrounding regions.  Lower lake levels definitely contributed some of this, but I wonder how much?

How did the lake shrink by 2/3's? That would be an environmental catastrophe I would think(like Aral sea).

[Black Hole]

How did the lake shrink by 2/3's? That would be an environmental catastrophe I would think(like Aral sea).

The lake was at its highest level on record in the 1980s (modern times) so it was bound to come down some. However we have had significant drought for several years which is lowering the level, but also more water is being diverted from the rivers for other projects. In the absence of water diversion the lake would be a good deal higher than it is. 

[Kayla]

Woke up to about 4" of new snow this morning. Once again the NWS here missed this one. As expected, precip rates were high enough for the snow to accumulated at 33-34º during the heaviest precip and then dropped below freezing as the snow continued. Definitely pretty remarkable considering it was 75º yesterday afternoon!

 

Still looks like another shortwave pushes through later this afternoon into tonight that looks to drop another 3-5" of snowfall. 

[Kayla]

Beautiful sunrise this morning!

 

[epiceast]

Woke up to about 4" of new snow this morning. Once again the NWS here missed this one. As expected, precip rates were high enough for the snow to accumulated at 33-34º during the heaviest precip and then dropped below freezing as the snow continued. Definitely pretty remarkable considering it was 75º yesterday afternoon!

 

Still looks like another shortwave pushes through later this afternoon into tonight that looks to drop another 3-5" of snowfall. 

Yea looks like all of the valley got snowfall this time, it snowed quite a bit at the airport it looks like. So how much higher are you than Bozeman proper?

[Kayla]

Yea looks like all of the valley got snowfall this time, it snowed quite a bit at the airport it looks like. So how much higher are you than Bozeman proper?

 

The above picture is actually from our condo right in downtown Bozeman at 4,800'. We're building a new home just south of town at 5,350' where it looks like about 6-8" fell. Pretty decent storm!

[epiceast]

The above picture is actually from our condo right in downtown Bozeman at 4,800'. We're building a new home just south of town at 5,350' where it looks like about 6-8" fell. Pretty decent storm!

Nice! Looks like Butte got a decent dump(.4 qpf), maybe their biggest this season. Has to be a frustrating winter there, so cold and so dry.