Mammoth Mt Storm Total 2 to 3 feet……For a two storm series total of 3 to 4 Feet…..Upper Low is Filling and will be out of Central Ca by this Evening…..
Saturday March 1, 2014
Posted at 8:00 am by Howard
Upper trof is now moving on shore over LA and taking the remains of the moisture with it. Lots of showers and thunderstorms in the LA area with a few real boomers!. With the upper blocking high exiting Alaska to Siberia, a flip in both the WPO and EPO will allow long wave trofing to reemerge between the Hawaiian islands and the Dateline. This teleconnects well with long wave ridging over the west coast and an upper jet displaced far to the north of us. This is the trend over the next 7 days. Initially the upper ridge will be dirty and so lots of high clouds over running the ridge, on and off next week. Possibly some showers later in the week around Wednesday or Thursday. The snow level will be high above 9K.
Of interest. Tropical Storm FAXIE has sustained winds of 50 knots. It is located at 149East and 10 North, moving North It will intensify the next 3 day and become a major Typhoon. Its moisture will eventually become entrained in the westerly’s. Northern Ca northward through the pacific NW and especially the BC coast is going to get a lots of rain from the short waves tapping that moisture source later next week For most of Central California, and southern is out of it as the upper ridge gradually builds and strengthens.
More food for thought:
Tropical storm FAXIE is developing because of an intensifying MJO between phases 7 and 8. (Western Pacific) The dynamic model forecasts the MJO to progress through phases 8, 1 and 2. however in the meantime the GFS and EC keep the MJO strong in phase late 7 and 8. Of note, there is the possibility of the reemergence of a southerly displaced EAJ with another Southern or Central CA weather event similar to the one just passing by mid March. The ECMWF is hinting at that now.
For the more advanced Dweebs…..Here are some composites correlating the MJO with its phase space, the month of year and the height field of what you might expect. (GOOD STUFF!) SEE: http://www.americanwx.com/raleighwx/MJO/MJO.html
Dr Howard and the Dweebs……………..:-)
Storm System Currently In The Sierra W/Snowfall rates this AM about 2 inches per hour….Several Bands of Moisture Continue to be Enhanced by Upper Jet……………..
Friday February 28, 2014
Posted at 9:45 am by Howard
Heavy Convective Snowshowers!
Main Vort Center moves through at 4:00pm
An Amazing 6” snowfall in one hour!!!!! Yes, between 3:00pm and 4:03 PM at the main lodge 6 inches fell according to the Plot at the base lodge! This brings the total to 18 inches at the main lodge and most likely about 2 feet on top. More to come tonight!!! At least another 6 to 12 inches by 10:00PM then another 2 to 4 by Morning Saturday. (On Mammoth Mtn)
As of 9:00AM:
At Mammoth Weather.com at the 8200 foot level I have picked up 7 inches of fresh since 5:00am. It is Snowing moderately at the moment. Temperatures have warmed up to 31 degrees since it was 27 at sunrise, an example of the Warm Sector of this system. Once the warm front has passed, we may have a short break before the Upper Jet enhanced colder precip arrives by 12:00pm. I suspect that we are at the highs for the day today because of the following…..
Fous 73 numerical data off the 12Z NAM show 1000-500mb Thicknesses at Fresno (FAT) 552DN at 12Z; then lowering to 548DM at 18Z. Thickness falls continue through the day/night. By 00z Saturday, 544DM then down to 542DM by 06Z Sat. What is interesting is that FAT shows a negative Lifted of -2 by 18Z and 0 lifted by 00Z. So do not be surprised if you hear some Thunder this afternoon in the Sierra. Probably mostly on the west side. I Checked the Vertical Motion…..it shows +12 at 18Z with the negative lifted of -2 then +20 in the max at 0 lifted. Thus this afternoon there is going to be some pretty vigorous rising air columns! Thunderstorms over the southern SJV you bet! Possibly some cold core funnels as well. The southern San Joaquin Valley will not be a good place to be flying if you’re in a small plane today!
Otherwise the snowfall forecast for Mammoth through Saturday is unchanged. 12 to 18“ in town and 20 to 30“ over the upper elevations……
PS, The MJO seems to be trapped between Phases 7 and 8. So for the time being the East Asian upper Jet will continue to be strong, for possibly another week. This give support to the ECMWFs version of the extended showing another significant storm for Wednesday or Thursday next week before we ridge up for my Sons Wedding on the 8th!
The Dweebs are doing what we can for you Cliff!…………..;-)
Tuesday February 25, 2014
Posted at 1:12 pm by Howard
Thursday AM Update:
Not much to add this morning…. I picked up 8.5 inches at the 8200 foot level and I understand that Mammoth Mountain picked up about a foot at the main lodge with up to 15 inches over the upper elevations. I personally estimate that with the water content and the colder temps, more like 17 inches is up there.
Storm #2 looks better for us then it did yesterday as the upper cyclonically curved jet and UVM between 17Z to 22Z will really pound the Mammoth Sierra. Additionally, looking at the 700mb heights and RH from the new 12Z Thursday WRF, there is now a fairly sustained period of quasi SW flow which will add orographic’s to the mix. The WRF has the upper flow over the Mammoth Sierra more southerly late tonight then becomes more Southwesterly about 15Z Friday. The 700 flow continues between Southerly and southwesterly on and off through the afternoon. So Mammoth is on the boarder of the 700MB flow that is between these two directions. This is much better then the last few days guidance with southerly flow. So the models may not have a complete handle on the QPF because of the potential now for orographic’s. IE We may get more snowfall from the Friday/Saturday storm than is predicted.
So we may get another 25 to 35 inches at 10:1 over the Mammoth Crest by Saturday night.
The longer range still shows the upper ridge building over the west coast with time……Next week will be unsettled with periods of snow showers but nothing strong at this time…..
Dr Howard and the Dweebs……………….
WHY SO MUCH QPF IN THE MODELS FOR THIS AREA?
I have been researching the reasons why the HPC QPF has been going so hog wild on the QPF for this particular area of the Sierra. I can understand why for LA and for parts of the Southern Sierra. However, why so far north with southerly flow and with little orographic’s in play for storm #2.
When you think about it, the reasons are not all that complicated. The answer I believe lies in the Upper Jet dynamics associated with Storm #1 and especially the 2nd storm.
In storm #1 the upper jet “was” expected to be pretty zonal across Southern California. Now it is coming in from the SW across Pt Conception. The Left Front Exit region is very close to Mammoth now with strong divergence aloft and a VT max just to the south of Mammoth. This in itself will give the QPF a boost later tonight, especially after midnight.
Storm #2 the upper jet is not zonal either. It is cyclonically curved, coming into Pt Conception early Friday AM and rotating up through the Owens Valley during the day. This creates strong UVM over the entire Southern Sierra chain up to Mammoth.. Thereafter, we become under the Cold Pool Saturday and Saturday Night with a lot of unstable air. Expect additional accumulations.
The upshot is about 4+ inches of water over the Pass…..
So there it is……………………!!
PS…. Trying to get the Mammoth WX data logger online later tonight…
I have not seen this much open cellular CU between 30N and 40N since the winter of 2011! It’s nice to see it happen again! All systems are go for one heck of a storm for Southern California Ca. The recent burn areas of my hometown in Glendora should take extra precautions now by sandbagging areas around homes below canyons.
The latest QPF is up to 8.5 inches from the latest HPC output in some of the coastal ranges of Pt Conception and the foothills of both valleys. There may be more rain in “some areas” that has fallen in two years down there.
So again the big story will be the enhanced Asian Jet that is making its way through the far eastern pacific. Both the EC and GFS is painting about 3 to 4 inches of water up on the Mammoth Pass. And if it were not for the best forcing to the south of us, this would be one of the EPIC and memorable 4 to 6 foot dump. Well instead have to settle for 3 to 4 feet over the crest and a couple of feet in town by weeks end. There is the chance that snow showers may continue for sometime after the storm is through Saturday, so that several more inches could accumulate over the upper elevations throughout the weekend and even a few into the following week.
There are two separate storms. A smaller storm Wednesday night in which the town will get 5 to 8 inches and the biggie Friday AM through Saturday 12 to 15 inches will fall. Approximately double that for the Crest…..
I see a small system about the middle of next week, mainly effecting Tahoe, then we ridge up for the following weekend of the 8th…..
After that well see…….
Dr Howard and the Dweebs…………………………:-)