Archive for March, 2019

Cold unsettled pattern to continue through mid-week next week…….As Winter winds down….A hole new set of concerns arrive….localized and lower level flooding Throughout California…….

March 18th 8:30AM

After a beautiful weekend, another series of storms will approach for mainly Southern and Central CA. High pressure aloft has formed a block over British Columbia Canada. The westerlies are forced underneath into CA. The systems are coming in negative tilt and so southerly flow will highlight the precipitation probabilities and thus a lack of orographics.    Latest RFC precipitation forecasts about an inch over the west side from the Wednesday Thursday storm. The Dweebs EST between 5 to 10 inches of snow on Mammoth Mt and between 3 and 5 inches in town by Thursday evening. Snow level will start at 7500 Tuesday night and low to 6000 feet Wednesday.  High temps in the 30s Wednesday.    They look to be a break Friday with another system Friday night and Saturday. This look to be another light to moderate precipitation producing system although it is too soon to fine tune amounts as of yet.   Another couple of storms are forecasted that following week…..

 

The vernal equinox occurs at 1:58pm this Wednesday the 20th.

 

The Dweeber………:-)

 

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Winter seems to be wrapping up with the present offshore trof that will bring snow showers and light amounts of snowfall accumulations. The two key periods seem to be Sunday as the off shore upper low settles south, and a deformation zone sets up over the Sierra and western Nevada. I would not expect much more than 1 to 3 inches from a pattern like this for Mammoth. There is another colder system headed our way as the long wave trof shift east for Tuesday into Wednesday. 1 to 3 inches…After that, high pressure aloft will begin to do its job the second half of next week. The ridge may not be strong enough to keep all the short wave energy out of the area, but it will keep any major storms out. Over time as we go through the third week of March….it appears to build even stronger.  Looking at the MJO, many of the models circle it around phases 3 and 4.  Phase 4 typically is dryer out west this time of the year while 3 can still produce some storminess. The Euro want to take it through and past the circle of death back into phases 8/1. That is the area of undercutting and that would typically brings us a warmer latitude storm track which California does not need. The timing for that should it occur is around the 20th.  BTW, The GFS does not not agree….it is more “Ridge City” as far as the eye can see….

However, the American Global Forecast System, ”GFS”, does really warm us up week 2 and that is concern enough because of the tremendous snow pack over the Sierra, especially in the mid elevations between 6000 feet and 8000 feet.  Flooding looks to become an issue at some point….

in the meantime, enjoy this weekend’s skiing and boarding at its finest, as spring skiing is on the way later this month.

PS, The IKON pass is now on sale through Mammoth Mt.  Get this years best price on this pass before April 24th.

 

Dr Howard and the Dweebs…….

Stormy February into March Pattern transition underway with much less snowfall in our medium range…..Longer Range seems to be continuing the trend through the next week…..

Our stormy pattern associated with this winters robust eastern pacific trof is weakening. This particular trof seems to be coming in, in parts now. As a result, different parts of California will have different experiences with this pattern. We may have some light snowfall into tonight. However, light snow showers seem to be the way to go Friday and saturday with a chance of a bit better forcing Sunday. The models handle the pattern differently. However the wettest model brings about a foot over the crest Sunday into sunday night and is being discounted at this time. Where other models give us less than half of that.  The resounding message here is that unsettled weather is here to stay for the next 5 days, but the Dweebs do not see a major storm.  It will turn colder toward mid-week next week as a cold California Slider drops south with more snow showers Tuesday.   Highs will be in the 30s, with lows in the teens….

As a comment, the end of this latest storm cycle was a bit of a disappointment for snowfall. Amounts over the past 7 days, totalled about 5 feet over the crest, not 7….

 

The Dweeber…….:-)

Current storm system continues to dump snow on Mammoth Mt Saturday, while next AR takes aim on the High Country Tuesday…..Several low pressure systems expected to migrate through our area Wednesday through Friday…..Colder air on the way for Friday…….MJO starting to be affected by ENSO….Diving into the circle of death…..

Wednesday 9:40AM

The snow plot at 9000 Feet showed about 3 inches of water and at the ambient temperatures at the summit in the mid 20s

that would translate to at least 2.5 feet of new snow at the summit. Another 2.5+ inches is expected through mid day Friday and so we may hit that 5 foot mark of new snow yet at the summit.  Officially at this time, up to 17 inches of snow has fallen at the main lodge.

Our AR has shifted south into Southern CA. cooler temps are on the way for Mammoth.  The latest model simulations show the present trof shifting south today through Thursday with more showery weather expected Thursday. A NW slider will keep the snow showers going Friday AM.    The next upstream system for Saturday seems to want to remain off shore far enough to keep most of the precipitation west of us. Although the upper jet is over Central CA Saturday, the vertical motion field is too far west. That is progged to change late Saturday night and Sunday as the system both nears the coast and shifts south down the coast……Precipitation chances should increase again in our area.

 

The Dweeber

 

 

 

 

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Monday AM

No changes this morning….mid latitude low and associated AR, are forecasted to begin bringing rain and snow to the region Tuesday. The snow level Tuesday my go up to as high as 8000 Tuesday morning, before coming down to between 7000 and 7500 Tuesday afternoon.   Winter storm watches are in place beginning 10:00AM Tuesday by the NWS. 1 to 3 feet is expected above 7000 feet by Wednesday night. The Dweebs believe another foot or two expected by Friday.  Models are changing their tune for the weekend. It may not be all that sunny, with another storm possible. With MJO diving into the circle of death and El Niño now coupling to  Larger scale planetary flow, will westerlies react according.

Sunday AM. 1050AM

Only changes to the Tuesday AR is that the polar and subtropical jets are only partially coupled. However, I am not concerned about the heaviest amounts for our area as the hose is pointed NE through the Inyo-Mono county boarder Tuesday. I think that unless there is enough vertical motion which is looking more unlikely Tuesday, it will be mostly rain or snow-rain mix for the Town of Mammoth until Tuesday night when the freezing levels drop.

Up on Mammoth Mt, it will be all snow at the main lodge and above with good base building SIERRA cement Tuesday and Tuesday night. This storm along with other colder systems next week should bring and additional 5 to 6 feet over the upper elevations by the following weekend. The longer range is showing signs of the winter machine getting tired.  The MJO goes into the circle of death. Whether or not this happens is another story for a later time as the low frequency base state of El Niño may be getting ready to exert more influence upon tropical forcing…Remember this El Niño is a Modoki and may bring a dryer pattern to CA in the not too distant future. Some of the ENSO models predict El Niño to strengthen over the Summer. I would be cautious buying into all that as the Spring Barrier is not all that far off.

 

The Dweeber………………..:-)

 

 

 

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The vertical motion in the current storm is rapidly increasing as the main Vort max is expected through our area by 03Z.   Lots of yellow lighting up the radar near Fresno at 2:00 PM…Thus it is becoming prime time for this storm. The current heavy snowfall will be tapering off to showers after 6 or 7 PM. Mammoth Mt reported up to 12 inches for overnight amounts in their morning update.  Up to another 12 inches is expected by this evening…. Storm total should be in the 12 to 24 inch range. Heavy wet snow was falling in the Town of Mammoth Saturday afternoon..

There will be a break in the action Sunday into Monday with only snow showers expected Sunday….It will be dry and a good travel day Monday.

The next series of storms will begin this Tuesday. There is an AR attached to it with the AR pointed just north of Point Conception.  The upper low coming in will draw up that subtropical moisture and point most of it into the Southern and Central Sierra. Mammoth appears to be right on the border of the richest portion of the AR, benefiting well from the AR. For the day Tuesday, there is little Vertical Motion indicated and so do not look for heaviest amounts on the east side. Amounts on the West Side will be heaviest because of the orographics. The Snow to Water ratios will be low on Tuesday as the AR moves in, with the freezing level as high as 8000 feet on Tuesday. It may be rain snow mix in town.  The Freezing level will begin to come down late in the day on Tuesday and into Wednesday. As the vertical motion field really cranks up Wednesday mid morning…  The Town of Mammoth should have its heaviest accumulation of snows late Wednesday AM and into Thursday as several low pressure impulses systems spin up into the high country. Although the AR will be pushing south by Wednesday,  the vertical motion increases for Mammoth and will deliver increasingly heavier amounts of snowfall beginning mid to late morning Wednesday as the colder air moves in as well. Heavy accumulations are expected in town late morning through Wednesday night. The vertical motion field stays strong through Thursday night.

Upper Jet;

Saturdays 18Z run of the gfs shows the polar upper jet over Northern CA within the Subtropical Ridge and both the polar and STJ coupled well off shore. This is supporting the AR as it comes into Southern CA. Over the following hours, the coupled polar jet drops south quickly Wednesday morning while still coupled.  WOW!!  The AR moisture gets sucked up over the Southern and Central Sierra Wednesday for a real Snow Day!! This continues through Wednesday night and into Thursday as the coupling continues into Thursday!  The freezing level goes from about 8000 feet mid day Tuesday to 7000 feet mid-day Wednesday to 6200 mid-day Thursday to 4200 feet Friday AM. By 4:00AM Friday, the upper low will be just to the south of us and so as of this time, it looks snow showery Friday and dry Saturday.  Looks like between 2 to 3 feet in town and some 3 to 5 feet on Ol’ woolly by Friday.

The next storm in the longest range for whatever it is worth,  looks to be the following Wednesday the 13th.

 

MJO;

The RMM phase space for the MJO shows it is currently in Phase Space 2 and into phase 3 over the next few days….These are all wet phases for Mammoth. However, the GFS has the MJO retrograding back to phase one and very weak by . The CFS has it back to 8-1 and week. Might this finally be the EL Nino coupling that we have been waiting for? More later on this, this Tuesday or Wednesday. By around the 15th the MJO looks pretty weak.

 

Dr Howard and the Dweebs………………………:-)