Here comes the Pineapple Express
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schubwa
New member
Howard Sheckter (Dweebs) just issued this warning to those who live near the Mammoth Lakes Sierra:
One more day “today” to make sure everything is in order.
Check list:
1. If you have a gas powered electric generator, make sure you have gas and it is working properly.
2. Snow blower working, extra sheer pins available and of course shovels handy.
3. It look like more snow now as the models are coming in cooler. Nevertheless, those that are in low lying areas of town should clear out their culverts to make sure they are free of debris.
5. We are expecting a good 3 to 4 inches of water EQ in the Town of Mammoth between Friday night through mid day Sunday. (2 to 3 feet+) High winds of 60 MPH in town, coupled with the heavy snow fall will create a loading problem for trees and power lines. Be prepared for possible power outages.
It will be a mess in town Saturday so CHAIN UP for 4WD may become a necessity.
Again the models have been trending a bit cooler the past 24 hours and so it may be, that the period of rain will be shorter lived for the town, which will impact the town with more snow. Avalanches may becomes a problem in non controlled areas. You folks in the June Lake loop should be prepared as well as you will get buried…..
Folks…this will be the kind of snow that you get stuck in. Even for 4WD’s. Very heavy, dense, moisture leaden cement. So get your chains ready for your FWD’s Saturday and be extra safe!
Better yet, probably a good idea to stay home!
UPDATE:
A deep Eastern Pacific closed low is forecast to drift toward the Pacific Northwest with the center remaining off shore into Sunday. This cold upper low and associated polar jet will combine with a fetch of tropical and subtropical moisture emanating out of another tropical low located along the date line at 23 north latitude. This tropical low which has been part of an ongoing REX block has been tapping moisture out of the ITZ. The under cutting subtropical jet and associated moisture will combine with the polar jet, north and east of the Hawaiian islands creating a copious precipitation event for both Northern and Central California. Then into next week……although the models retrograde the tropical low…..the remaining moisture train continues a few more days and continues to be entrained, into the long wave trof parked off shore.
A steady stream of moisture along with strong upward vertical motion will impact the northern 2/3s of the state. The upper jet aligns from Oregon to Central Ca through the weekend gradually sliding southward. This mornings the latest guidance still shows that the heaviest precip will be through Northern and Central Ca….with QPF totals, according to HPC, up to 6 inches by Sunday morning. Another 5 to 6 inches is expected between Sunday morning and Tuesday morning.
Outlook: More storms on the way over the holiday with breaks……
One more thing……although the REX block breaks down the middle of this week…it redevelops the following week…..
Update Friday:
On the realm of Global warming and Global cooling……
Did you folks know that the sun is unusually quiet?
In fact it is spotless again this morning.
Geoff Sharp is a solar scientist.
Below are his comments this morning…..
2010/12/16 8:00 1133 is still just visible but is under the threshold at 240 pixels. There is a small speck region measuring 83 pixels in the early northern region that shows some potential on the magnetogram. There is also another region on Stereo Behind about to rotate on that may be worth watching. Its cold in the NH right now, the predicted massive northern winter is beginning to happen.
Yesterday’s adjusted F10.7 flux figures measured at 20:00 UTC recorded 84.2 (87.5), on the way down again. The DSN value for today is 110 with the previous measurement at 214.
Looks like us PNW'ers are going to be in the colder "top drawer" of this series. Whoosh!
One more day “today” to make sure everything is in order.
Check list:
1. If you have a gas powered electric generator, make sure you have gas and it is working properly.
2. Snow blower working, extra sheer pins available and of course shovels handy.
3. It look like more snow now as the models are coming in cooler. Nevertheless, those that are in low lying areas of town should clear out their culverts to make sure they are free of debris.
5. We are expecting a good 3 to 4 inches of water EQ in the Town of Mammoth between Friday night through mid day Sunday. (2 to 3 feet+) High winds of 60 MPH in town, coupled with the heavy snow fall will create a loading problem for trees and power lines. Be prepared for possible power outages.
It will be a mess in town Saturday so CHAIN UP for 4WD may become a necessity.
Again the models have been trending a bit cooler the past 24 hours and so it may be, that the period of rain will be shorter lived for the town, which will impact the town with more snow. Avalanches may becomes a problem in non controlled areas. You folks in the June Lake loop should be prepared as well as you will get buried…..
Folks…this will be the kind of snow that you get stuck in. Even for 4WD’s. Very heavy, dense, moisture leaden cement. So get your chains ready for your FWD’s Saturday and be extra safe!
Better yet, probably a good idea to stay home!
UPDATE:
A deep Eastern Pacific closed low is forecast to drift toward the Pacific Northwest with the center remaining off shore into Sunday. This cold upper low and associated polar jet will combine with a fetch of tropical and subtropical moisture emanating out of another tropical low located along the date line at 23 north latitude. This tropical low which has been part of an ongoing REX block has been tapping moisture out of the ITZ. The under cutting subtropical jet and associated moisture will combine with the polar jet, north and east of the Hawaiian islands creating a copious precipitation event for both Northern and Central California. Then into next week……although the models retrograde the tropical low…..the remaining moisture train continues a few more days and continues to be entrained, into the long wave trof parked off shore.
A steady stream of moisture along with strong upward vertical motion will impact the northern 2/3s of the state. The upper jet aligns from Oregon to Central Ca through the weekend gradually sliding southward. This mornings the latest guidance still shows that the heaviest precip will be through Northern and Central Ca….with QPF totals, according to HPC, up to 6 inches by Sunday morning. Another 5 to 6 inches is expected between Sunday morning and Tuesday morning.
Outlook: More storms on the way over the holiday with breaks……
One more thing……although the REX block breaks down the middle of this week…it redevelops the following week…..
Update Friday:
On the realm of Global warming and Global cooling……
Did you folks know that the sun is unusually quiet?
In fact it is spotless again this morning.
Geoff Sharp is a solar scientist.
Below are his comments this morning…..
2010/12/16 8:00 1133 is still just visible but is under the threshold at 240 pixels. There is a small speck region measuring 83 pixels in the early northern region that shows some potential on the magnetogram. There is also another region on Stereo Behind about to rotate on that may be worth watching. Its cold in the NH right now, the predicted massive northern winter is beginning to happen.
Yesterday’s adjusted F10.7 flux figures measured at 20:00 UTC recorded 84.2 (87.5), on the way down again. The DSN value for today is 110 with the previous measurement at 214.
Looks like us PNW'ers are going to be in the colder "top drawer" of this series. Whoosh!
Adam just finished up first semester, but we are waiting until next Monday/Tuesday before considering going to Mammoth.
This storm is almost certainly bad news for the SoCal local ski areas.
This storm is almost certainly bad news for the SoCal local ski areas.
berkshireskier
Active member
Yea, Accuweather is predicting 10 to 15 FEET of snow for the high peaks of the Sierras. Is it even possible to ski in that much snow? LOL And does a ski area groom out that much snow?
These storms tend to be high density snow, often accompanied by a lot of wind. Often it ends up so packed that the Utards wouldn't even consider it powder. A personal example: viewtopic.php?t=1573 But as I noted then, this type of storm is why we're still skiing in July some years. If you're going to be skiing during a storm like that you want to be in the trees, probably away from the Sierra Crest at a place like Northstar. You do not want to be at an high alpine area on the Sierra Crest like Mammoth, Squaw or Alpine Meadows because most of the lifts will be closed during the storm.berkshireskier":1hdbuthm said:
Below treeline on typical intermediate runs it's not particularly different than usual. Above treeline they aren't going to do anything until avy control is complete. On the roads it's a different story, can be a huge headache. Tahoe and the roads getting in are a nightmare. Mammoth is somewhat easier to manage as storm intensity drops off a lot by the time you get to Hwy 395 three miles east of town.berkshireskier":1hdbuthm said:
Just got back from Brighton. Good thing that snow is coming soon; conditions are blecch: rock-hard styrofoam.
I was getting spoiled after two powder days at Grand Targhee.
I was getting spoiled after two powder days at Grand Targhee.
schubwa
New member
Read this and learn that this week's pattern is not a true "Pineapple Connection":
Snowfall began at 3:00am this morning and is now expected to continue for several days. No surprises this morning with QPF on track. Updated HPC 5 day amounts for the south central sierra is up to 14 inches over the period along the west side and 9 to 10 inches over the crest. This means that Mammoth MT is likely to receive a good 10 to 12 feet in the coming 5 days. (10:1 ratio)
The Town of Mammoth 4 to 6 feet. It still appears that for the most part, it will all be snow for the town. There are several waves within the subtropical fetch now currently connected to the central coast. Periods of strong vertical motion will coincide with heavier snowfall rates. Moisture Flux Divergence within the flow is expected to be extreme.
As far as the models go over the next 3 or 4 days…..the large upper low in the gulf of Alaska will remain pretty much stationary with a swift zonal flow underneath that system. The upper jet at 160knots stretches from 160w to the west coast just south of 40 north. The little eddies or impulses that streak across the zonal flow are enhanced areas of vertical motion and represent potential heavier areas of precip when they move on shore.
Looking at the CIRA TPW loop from AMSU http://amsu.cira.colostate.edu/TPW/global.htm You can see the juice up to 35 to 40 mm within the stream . A subtropical upper low near 30 north- 175 west is keeping the pump juiced.
Analogs:
There has been some talk around town of this being a pineapple connection. A pattern similar to February 1986. This is not true. The February 16 through 19th event was a true pineapple connection.
The analog shows that a blocking high became cut off over Alaska while the typical upper jet diverged to the right and dug back an upper trof that became confluent with the subtropical jet which road over a subtropical ridge into California. The 500mb heights over Mammoth went as high as 570dm and we had 6 to 7 inches of rain over a heavy snow pack. That was the winter that the Sherwin’s slid.
This system is totally different. Instead of high pressure in the northern Gulf of AK, there is a deep vortex. The blocking high is out near the dateline in a quasi REX configuration. Check out the analog at http://vortex.plymouth.edu/reanal-u.html then compare to current 3 day means.
Better analogs are 1968 11/28; 1971 11-28; 1961 12/22 and 1966 11/29
PS: I was living in Old Mammoth in Feb '86 and had been shoveling for days out on Evergreen St. It had been snowing mercilously for days and then it rained. I was walking in to work at Whiskey Creek through the meadow and I got a glimpse of the "Lone Pine" slide. A huge climax avalanche had taken out an entire mountain side in the Sherwin Bowls. Only a lone pine was left standing. The smell of broken timber hung in the air for weeks.
Snowfall began at 3:00am this morning and is now expected to continue for several days. No surprises this morning with QPF on track. Updated HPC 5 day amounts for the south central sierra is up to 14 inches over the period along the west side and 9 to 10 inches over the crest. This means that Mammoth MT is likely to receive a good 10 to 12 feet in the coming 5 days. (10:1 ratio)
The Town of Mammoth 4 to 6 feet. It still appears that for the most part, it will all be snow for the town. There are several waves within the subtropical fetch now currently connected to the central coast. Periods of strong vertical motion will coincide with heavier snowfall rates. Moisture Flux Divergence within the flow is expected to be extreme.
As far as the models go over the next 3 or 4 days…..the large upper low in the gulf of Alaska will remain pretty much stationary with a swift zonal flow underneath that system. The upper jet at 160knots stretches from 160w to the west coast just south of 40 north. The little eddies or impulses that streak across the zonal flow are enhanced areas of vertical motion and represent potential heavier areas of precip when they move on shore.
Looking at the CIRA TPW loop from AMSU http://amsu.cira.colostate.edu/TPW/global.htm You can see the juice up to 35 to 40 mm within the stream . A subtropical upper low near 30 north- 175 west is keeping the pump juiced.
Analogs:
There has been some talk around town of this being a pineapple connection. A pattern similar to February 1986. This is not true. The February 16 through 19th event was a true pineapple connection.
The analog shows that a blocking high became cut off over Alaska while the typical upper jet diverged to the right and dug back an upper trof that became confluent with the subtropical jet which road over a subtropical ridge into California. The 500mb heights over Mammoth went as high as 570dm and we had 6 to 7 inches of rain over a heavy snow pack. That was the winter that the Sherwin’s slid.
This system is totally different. Instead of high pressure in the northern Gulf of AK, there is a deep vortex. The blocking high is out near the dateline in a quasi REX configuration. Check out the analog at http://vortex.plymouth.edu/reanal-u.html then compare to current 3 day means.
Better analogs are 1968 11/28; 1971 11-28; 1961 12/22 and 1966 11/29
PS: I was living in Old Mammoth in Feb '86 and had been shoveling for days out on Evergreen St. It had been snowing mercilously for days and then it rained. I was walking in to work at Whiskey Creek through the meadow and I got a glimpse of the "Lone Pine" slide. A huge climax avalanche had taken out an entire mountain side in the Sherwin Bowls. Only a lone pine was left standing. The smell of broken timber hung in the air for weeks.
And here's what happened on Drop Out in February 1986:schubwa":1w1ow9sx said:
that picture always amazes me.
Just got back a great 3 days at Mammoth June.. left yesterday in the beginnings of the storm. Mammoth is reporting 38-54" new this morning. 8-[
here in Socal....I can unfortunately report from across the street from Mt. High at 7,000 ft... it's rain and 36 degrees. their 6-12" base is going to be gone by tomorrow.. We can hope maybe the early week storm will be a little colder and save the socal ski areas from total disaster. [-o<
Just got back a great 3 days at Mammoth June.. left yesterday in the beginnings of the storm. Mammoth is reporting 38-54" new this morning. 8-[
here in Socal....I can unfortunately report from across the street from Mt. High at 7,000 ft... it's rain and 36 degrees. their 6-12" base is going to be gone by tomorrow.. We can hope maybe the early week storm will be a little colder and save the socal ski areas from total disaster. [-o<
tseeb
Well-known member
Mammoth at 2 pm reported 44-60 inches in the last 24 hours.
Tahoe may have been OK if you were both high enough and where the wind did not keep lifts from opening. Hwy 88 West of Kirkwood (The Carson Spur) was closed all day and Squaw did not open KT-22, let alone the upper mountain.
And it''s getting worse. At 5:45 PM South Lake Tahoe reported 40 degrees and Truckee 32. At 7:45 PM Truckee was up to 35 and South Lake Tahoe 41.
Tahoe may have been OK if you were both high enough and where the wind did not keep lifts from opening. Hwy 88 West of Kirkwood (The Carson Spur) was closed all day and Squaw did not open KT-22, let alone the upper mountain.
And it''s getting worse. At 5:45 PM South Lake Tahoe reported 40 degrees and Truckee 32. At 7:45 PM Truckee was up to 35 and South Lake Tahoe 41.
For Tahoe I usually compare the Squaw 6,200 vs. 8,200 snow numbers during events like this. For example:
Dec. 3-6: 4 inches at 6,200, 23 at 8,200, that's mostly rain at the base
Dec. 14: 0 at 6,200, 12 at 8,200, a wet start to the current system
Dec. 15-17: 22 at 6,200, 28 at 8,200, looks like snow top-to-bottom
Dec. 18-19: 11 at 6,200, 28 at 8,200, some mix at the base.
Dec. 3-6: 4 inches at 6,200, 23 at 8,200, that's mostly rain at the base
Dec. 14: 0 at 6,200, 12 at 8,200, a wet start to the current system
Dec. 15-17: 22 at 6,200, 28 at 8,200, looks like snow top-to-bottom
Dec. 18-19: 11 at 6,200, 28 at 8,200, some mix at the base.
schubwa
New member
I hope Howard doesn't mind, but this is such fascinating reading.
Another Major Surge of Moisture into Mammoth today then Hose to Shift South into Southern Ca Monday into Wednesday…..more snow for Mammoth through Mid Week
SUNDAY DECEMBER 19, 2010
Posted at 10:52 am by Howard
Satellite imagery shows a strong short wave trof about 700mi west of the crest moving toward the Northern California coast. This system is associated with the cold vortex and northern branch of the upper jet . As it intersects with the fire hose coming in from north of Hawaii, another excessive period of snowfall is expected over the Southern and Central Sierra today. AMSU PWV are once again near 1.5 inches. The OAK sounding showing saturation for much of the column and is -22within the dendritic growth zone.
Bishop reported heavy rain mid morning with some power outages report as well in both Mono and Inyo counties.
Today and into tonight will be the heaviest snowfall for Mammoth. As the latest storm moves in to the Sierra, precipitation will focus along the entire length of the Sierra. Up-slope conditions are ideal with 700-MB winds from the southwest in the range of 45 to 65Knots. Add dynamics and you have periods of 2 to 4 inches an hour snowfalls. Expect this extremely heavy snow falls through early evening……then the intensity should slowly decrease as the cold front moves south.
Snow levels will be falling later today and into tonight behind the front.
The heaviest precipitation shifts southward into Southern Ca Monday…however, plenty of snowfall is still likely for the Mono County Sierra early to middle of next week.
Another 7 to 9 feet is possible between 4:00am Sunday through Tuesday over the sierra crest. The Village at of Mammoth could see another 2 to 3 feet by Midnight tonight .
The Dweeber…………………..
Another Major Surge of Moisture into Mammoth today then Hose to Shift South into Southern Ca Monday into Wednesday…..more snow for Mammoth through Mid Week
SUNDAY DECEMBER 19, 2010
Posted at 10:52 am by Howard
Satellite imagery shows a strong short wave trof about 700mi west of the crest moving toward the Northern California coast. This system is associated with the cold vortex and northern branch of the upper jet . As it intersects with the fire hose coming in from north of Hawaii, another excessive period of snowfall is expected over the Southern and Central Sierra today. AMSU PWV are once again near 1.5 inches. The OAK sounding showing saturation for much of the column and is -22within the dendritic growth zone.
Bishop reported heavy rain mid morning with some power outages report as well in both Mono and Inyo counties.
Today and into tonight will be the heaviest snowfall for Mammoth. As the latest storm moves in to the Sierra, precipitation will focus along the entire length of the Sierra. Up-slope conditions are ideal with 700-MB winds from the southwest in the range of 45 to 65Knots. Add dynamics and you have periods of 2 to 4 inches an hour snowfalls. Expect this extremely heavy snow falls through early evening……then the intensity should slowly decrease as the cold front moves south.
Snow levels will be falling later today and into tonight behind the front.
The heaviest precipitation shifts southward into Southern Ca Monday…however, plenty of snowfall is still likely for the Mono County Sierra early to middle of next week.
Another 7 to 9 feet is possible between 4:00am Sunday through Tuesday over the sierra crest. The Village at of Mammoth could see another 2 to 3 feet by Midnight tonight .
The Dweeber…………………..
snowboard247
New member
Easily the most snow i have ever seen. The mtn is now reporting 11.5-16.5 feet of new snow. We are water content wise where we would be mid to late february on an average year. Some of the heaviest snow fall rates I have ever seen. There were a few hours of sustained 4-5 inches of snow per hour. It was almost scary how much snow fell in such a short amount of time.
Another archive picture of the debris from that February 1986 slide on Drop Out:
rfarren
New member
Looks like the whole side of the mountain gave out.
On a side note, the west looks to be drying out for a while. Sadly just in time for my trip to Utah next Thursday. Nonetheless, all the terrain should be open, so it should yield good skiing, and I don't arrive till thursday which is ways away so you never know, but according to the GFS, Crocker and I have a problem with bringing drought to Utah.
On a side note, the west looks to be drying out for a while. Sadly just in time for my trip to Utah next Thursday. Nonetheless, all the terrain should be open, so it should yield good skiing, and I don't arrive till thursday which is ways away so you never know, but according to the GFS, Crocker and I have a problem with bringing drought to Utah.
Lots more pictures (on both pages) of the Drop Out avalanche of February 1986: http://forums.mammothmountain.com/viewt ... =14&t=9284