Transitionary pattern over the pacific will initiate slow height rises over the West Coast next 12 days…..Another 2 or 3 unsettled periods for Central CA this week, then mostly dry next week
Tuesday March 4, 2014
Posted at 8:01 am by Howard
The current blocking high latitude upper high over Eastern Siberia will continue to shift west then weaken over the next 10 to 12 day….This according to the ECMWF 5 day means. Through this transition, a long wave trof slowly deepens between the Hawaiian islands and the dateline, with significant height rises occurring over the west coast.
The warm air advection pattern now occurring over North Central and Northern California and through the Pacific North west comes to an end early next week. There apparently will be two or three more waves to effect the Central Sierra including Mammoth Lakes thru early next week. The one short wave coming in Thursday Am, and the other the very end of this week like late Saturday night or Sunday. Both have the capability of producing a trace to an inch or two at the main lodge, especially the one for Thursday and again Monday. These systems for the most part this far south may give the higher elevations of Mammoth Mtn 2 to 3 inches. These are warm pushes of moisture over the Sierra that are mainly directed to Tahoe north with the Mammoth location highlighted by high snow levels, generally above 8500 to 9000 feet. Each system will be accompanied by gusty winds, but not high winds as the upper jet is well north of the area.
Retrogression of the long wave ridge position will take place after mid month during that 3rd week of March. That will be the time when we will return to a pattern of NNW sliders with colder storms with the potential for light to moderate snowfall.
The Dweebs are off the rest of this week….returning next week…..next update Tuesday the 11th of March.
Dr Howard and the Dweebs……………………………..:-)
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!…………..;-)