Archive for year 2016

Cold Trof developing over the east will set up over the next 5 to 7 days forcing the West Coast Ridge to build as well….Expect small systems to bring mainly light amounts of snowfall through next Friday…….

Friday the 8th:

Current conditions…Light snow showers..

Weak impulses from the back side of the storm that moved through Thursday Am will produce unstable air and some snow showers today. Little if any accumulation is expected today.

Highs today in the 20s…. Lows tonight in the teens….

There is another small system coming in late tonight and into Saturday Am. We may pick up a couple of inches by Midnight today with a few more inches Saturday AM….

It looks dry Friday with partly cloudy skies and a few flurries…

 

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Its nice during the winter to get a break  in the action for a while. That is what is expected for about a week here in the high country.  With that said, we will still have periods of snowfall but the weather systems will be weak.

Looking at the latest guidance this morning the models are continuing the trend in strengthening the negative phase of the AO. This will be good for the east in  getting snowfall during the next 7 days.  Over the far west and California, I am seeing the development of an amplified west coast ridge, ridged up into Western Canada. Again…The ridge is forecasted to be highly amplified but narrow. This is not the kind of ridge we have seen the past few years that blocked storms for week’s and months on end as we have the strong El Nino related southern stream….   The ridge will have several effects. 1. It will weaken incoming pacific storms for the next 7 days. 2. It will allow temperature’s to warm in the upper elevations. At 8000 feet, daytime highs will climb to the 40s by Mid Week. This many be our *January thaw!

The Dweebs expect periods of light snowfall. There is a system that will bring about 1 to 3 inches in town Saturday and 3 to 6 inches on Mammoth Mt. Another weak system Monday afternoon into Tuesday AM; 1 to 3 inches. And yet another system the Following Wednesday night and Thursday. That one may be light to possibly moderate.

By Friday the East Coast Trof is forecasted to begin to be pulled out into the North Atlantic by the Strong Southern Stream. This is yet another pattern change and we’ll have to wait to see what happens next.  Chances are that we will have some light snow over the holiday, bit it is too soon to say that we’ll have a significant storm.  The Dweebs should have a better handle on the MLK weekend by next Tuesday….

*Next week is a good time for locals to remove or have snow build up removed from their roofs along with Ice Dams. If you have the time, and your Eves are easily and (((“safely accessible”))), after removing the snow, try pots of hot water to break up the dams after icicle’s have been removed….You will need some help, however, it’s worth the time…. Again, this is a very-very dangerous task, so only attempt if you know what you are doing….  Better to have professional’s do it for you….  Ice dams are the number one causes of roof leaks from winter snow buildup.

Another 12 to 18 inches has fallen the past 24 hours on Mammoth Mt bringing Snow Totals over the crest to around 4 feet…..Although no major storms on the horizon….There will be additional snowfall into next week….Some very interesting development’s coming up in the long range…..

Another good snowfall over the past 24 hours in Mammoth with approximately 12 to 18 inches of new over Mammoth Mt and some 4 to 8 inches in town. These were not the totals we expected, as much of the storms energy remained off the coast then inland over Southern California, El Nino Style…..

Once again we are seeing a change in the pattern as the eastern half of the CONUS gets cold Trofing….  This will take the energy out of the big storms, as the west coast temporarily experiences height rises (Higher pressure aloft) with the tendency for weaker storms next week….  However, with this said, we will get more snowfall…

Currently the upper cold trof that is exiting the region will keep our air mass unsettled today lending the chance for more snow showers.  A couple of inches of snowfall is certainly possible. The next system that is headed our way will move in just after midnight Friday night and bring light to moderate amounts to our resort Saturday/Ngt. Expect around 3 to 7 inches in town and 7 to 12 inches over Mammoth Mt Saturday through Saturday Night.

By Sunday the Eastern CONUS trof will deepen and the wave length will shorten leading to sharp ridging near the west coast.  This will make forecasting tricky as it is possible that systems will either punch through the ridge weakening as they do bringing light showery snowfall. Another possibility is that a short wave comes through the ridge to the north of us, then rapidly diverges to the south….spinning up as a closed low over the top of us as it heads south toward SO-Cal. Either way…these are not the type of systems that are big snow producers…..They bring mainly cold-showery light snowfall.

OUTLOOK: (Long Range)

This is not a forecast but just something to keep in you back pocket…..  Most of the Inter-seasonal models are giving us a nice break over the Martin Luther King holiday weekend.  This is in the week 2 period….   What I want to blog about is the possibility of another storm cycle around that time frame….or just beyond

 

Here are some thoughts.

  1. We have a strong -AO at the moment that is expect to remain for the next 2 weeks at least.  The PNA is positive.  (If you want to know what these teleconnections mean, I have already addressed them in recent discussion’s…
  2. Due to the Eastern CONUS trof in development,  a narrow but highly amplified ridge will develop along the west coast over the next 5 days….This ridge is not the type of ridge that is likely to block the tremendous energy of the southern stream that is barreling across the pacific due to El Nino. There is the possibility of a bust in the Dam (ridge) later next week with a resulting break through of the westerlies. The fact that NCPB ( Bias-Corrected Ensemble Global Forecast System) for the  “MJO” is in *phase spaces 7 and 8 and rotating within that area means that there is a tremendous amount of convection and constructive interference going on with the ENSO base state. The location is near the dateline and east north of the equator. The SOI is still tanked negative, so something has to give….  I know that some forecasters are saying that the GFS is out to lunch and the MJO is really progressive, but the GFS has been touting it for several days now and again today.   Look out for the “possibility of a bust in the Dam (break through in the westerlies) late next week or just past in the week beyond….  Again…..this is not a forecast just some interesting curiosities…

* http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncpb.shtml

Dr Howard and the Dweebs……………………….:-)

Long Awaited El Nino/MJO Forced Storm Cycle has finally Developed after a 6 months wait………Southern Stream energy gets ready to deliver……

WINTER WEATHER ADVISORY IS IN EFFECT FROM 10:00 AM WEDNESDAY MORNING THROUGH
4:00AM THURSDAY……   AREAS ALONG HIGHWAY 395 SOUTH OF MONO LAKE MAY 
EXPERIENCE
WINTER STORM WARNING CRITERIA INTO EARLY THURSDAY AM….

Tuesday 1:00PM

Some interesting possibilities for week two. (Wednesday through Tuesday the 20th).

The Dweebs are looking at both the MJO phase space forecasts from the GFS (American Model) and ECMWF (EURO) Model

The GFS has the MJO doing circles between Phase 7 and 8 and the ECMWF has it progressive into Phase 1 and 2.

Look at these:

GFS Ensemble:  http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncpb.shtml

ECMWF Ensemble:   http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmf.shtml

Comments: 

It would be unusual for the MJO to get stuck in Phase 7/8….So week two in the GFS is probably out to lunch

However it is interesting to see what a phase 7/8 does to the pattern week two. The 12zGFS shows it being very wet for California with a possible very nasty Pineapple Connection to the west coast. Again this is not likely…..

The ECMWF would support more splitting of California systems early next week and I think that is the more likely scenario…

Will see if there is a compromise somewhere….

 

The Dweeber……………………..:-)

 

 

 

Tuesday 11:00 AM

Our 1st significant storm of the new pattern is into the Sierra and most of California at the moment.  Up to 8 inches of rain is forecasted for parts of Southern Ca over the next few days and some 3 to 4 feet of snow expected for Mammoth Mt between the two storms. IE. todays and Wednesday/Thursdays.  The Dweebs have been touting all this for two weeks now and will now shift gears and focus on the bigger picture and longer range as the current pattern is old news, although to some extent….Unrealized….

In yesterdays early AM discussion, I made a big point of what we can expect from the current southern stream and what happens in the east will affect the far west.  What is interesting about the current pattern over the Pacific is that all teleconnections seem to be moving along quite well.

To Wit:

  1. Very strong negative SOI…Providing that tropical support to the overall January warm ENSO pattern
  2. Strong Negative phase AO  Anomalous positive heights over the polar region, initiated by the strong MJO recently
  3. Strong Negative Phase EPO  Anomalous positive height anomaly in the far north GOA and AK.
  4. Strong Positive PNA  (Anomalous Positive Height anomaly over  Western Canada N/S

 

Everything is working well together!

However, the only fly in the ointment is the occasional trof in the east. This will impact the west coast ridge and cause the southern branch to split to the south or consolidate to the north.  What is coming up in our future is classic of that!!

The Thursday storm as it pushes east to the US mid section will phase with a system dropping put of South Central Canada. This will provide for a fairly deep cold low over the Ohio Basin south.  While it is travels east, the far west will ridge up and deflect any major storminess from California.

The Southern Stream related to El Nino will come to the rescue and flush the cold system out over the Atlantic so that we may be able to get storms again later next week…. If by chance this cold system gets reinforced…our break in the pattern will last longer…

Eastern CONUS Cold Air Aloft = A Trof or large scale storm in the east. These systems often times become a thermal anchor, as in years past,  a stormy east causes a warm dry west.  With El Niño’s associated strong southern stream, any Trof that does set up in the East this Winter will likely be progressive. This is because the Subtropical will flush it out off the east coast. During most winters it becomes a fixture and California can go weeks or even months without a storm…

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5:40PM update:

Some light snowfall this afternoon but nothing measurable in town…

As expected this first storm split and went south into Baja.  Some areas of moderate rain reported this morning in the LA Area.

The next system moving in will be a better precip producer as the system will not split nearly as much.  1 to 2 feet is still expected for the Tuesday PM storm.

Storm # 3 looks the best right now with another 1 to 2 feet possible between later Wednesday AM and Thursday AM.

A smaller system is expected over the weekend.

 

Beyond the weekend there was some major changes in both deterministic model runs of the GFS and EC.  They involve a rather cold system that drops down from Canada and phases with Thursdays storm later in the week over the east central US.  Not too sure what to think of a big storm for the east now when it was not there yesterday…..  Note a cold storm in the east could possibly put the KABASH on a wet week 2 for California.   Well see how it all shakes out in a day or two.

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It seems like its been a long wait but its January now and its show time For El Nino…….

I. I think that it is important to keep a perspective of what the biggest issues that the global models will be dealing with over the next several months:

  1. For the most part, El Nino forces a positive phase to the Pacific North American Circulation pattern. (Acronym) (PNA) (Anomalous heights aloft over Western Canada and Eastern Alaska)
    a. The frustrations of many waiting for the southern stream to arrive were based upon the fact that the PNA was negative and thus the Pacific Northwest was wet and it was drier the further south you went down the west coast.
    b. Now the PNA is positive and there is a formidable block in the PNA region that helps split the upper jet, sending more energy into the west coast from the lower mid latitude’s.
  2. Currently, the (MJO) The Madden Julian Oscillation is exceptionally robust for a strong El Nino and is constructively interfering with the El Nino Base State over the Central Pacific. Forecasts a week ago showed this convective envelope traveling from the Indian Ocean/Western Pacific eastward to the Central Pacific. Forecasts have subsequently grows stronger with this system. Readings in the SOI went from +30 indicating strong convection north of Australia during the convective phase of MJO to -33 as the SOI crashed due to the reactive suppressed state of MJO.  Strong westerly winds have resumed along the equator between Darwin and Tahiti. As indicated by MET; J. Bastardi, this acts as a cattle prod to the atmosphere. SEE: http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncpe.shtml
  3. Another Important teleconnection to a wet California in January, according to composites, is a Negative Phase (-AO) in combination with a +PNA, MJO strongly into Phase 7/8.  You may have heard that the north pole is very warm. This is due to the Arctic Oscillation going strongly negative by which higher heights are dominating the Northern Hemi Polar region, and forcing lower heights along with an upper jet displaced anomalously south.

 

II. Had a nice conversation with retired WSFO-RNO Lead, T.C over the weekend. It was agreed that what will be important this winter is to watch what happens over the Eastern CONUS. Those watching the global models the past week may have noticed the flip- flopping of the west coast systems and how much QPF they are painting. They are reacting to what is happening downstream over the east. The key in any warm ENSO pattern is how strong/persistent the subtropical jet is, as it travels from BAJA through Texas, and parts of the south, then veers strongly North East.  This needs to happen continuously so the cold air from Canada can get flushed out over the Atlantic. As if it gets bottled up for some time, that can weaken the incoming storms, split the west coast upper flow or if the cold air gets entrenched, ridge the west coast up in a full Latitude block. At this time we have “Constructive Interference” in the El NINO base state with a strong robust MJO. The Subtropical jet is likely to remain strong for several days to come.

So from a Forecast/Outlook point of view, the storm track is now set up for a series of storms this week with a break then another series that will likely last a week or two. The wave length between the east and west coast will be key to how much snowfall gets east of the Sierra Crest. The trend will be for warmer and wetter storms week 2, as heights rise a bit along the west coast in reaction to the MJO shifting east. This in turn forces a long wave trof  or (Adjustment Wave)  to deepen over the EAST-PAC as the upper flow becomes SW from the Tropics/subtropics . Remember the MJO helps to modulate the westerlies and so its phase state will need to be watched, for the purposes of predicting the retraction or extension in the East Asian Jet to the west coast in weeks 2 and 3.

 

The Forecast is for snowfall most days this week with moderate to possibly heavy amounts.  The Dweebs forecast between 1 and 2 feet by Wednesday AM.  Although there are more systems likely into the weekend…A Big Question this morning is….Will the Tuesday Afternoon/Night storm be the biggest or will it be the Wednesday night storm?   Clue…..A lot depends on what happens in the east…….;-)

More later……………………>>>>