Unsettled Weather Pattern To Continue this Week….Ramping up next week with “Potential” for AR….

Snowfall Forecast for the Wednesday Night Thursday system:

2 to 4 inches in Town with 4 to 8 inches over Mammoth Mt

Best Accumulations will occur by early afternoon Thursday.

Light accumulations through Thursday night with snow showers.

*Climate Forecast System Shows potential for significant “AR” next week

While European Model forecasts another 4 inches of water possible over the crest by the end of next week.

*

 

 

From Mondays Mornings Weather Letter:

In writing this Mondays Weather Letter, I cannot help to think back to the beginning of fall in October, when the first storms hit the Eastern Sierra. I find it so fascinating that the drivers of the great winter of 2016-17 are still ongoing now since last fall. “Except of the change of ENSO”. I still see the same Teleconnections driving the storm track into California today. The same ones that brought us the big sierra storms of yesterday. I know that if it were January or February now, today, instead of April, we would be getting hammered by the same pattern that has been with us all Winter and most of the Fall.

I am beginning to think about next winter. In doing so I will focus more on ENSO. The EL Nino Southern Oscillation. Many ocean climate scientists will be extra cautious this year in forecasting a significant EL Nino because of the bust of the winter of 2015/16.  Nevertheless, weather dweebs like myself are watching important changes in the sea surface temperatures, now affecting the Indian Ocean off the coast of Western Australia.  Very cold water has formed in that region along its west coast. Cold water is denser than warm water and the winds will flow east toward the warm waters of eastern Australia. I will be watching to see if this colder than normal water works its way south then surrounds that country to the north along its east side.  Westerly wind bursts may develop from the Indian Ocean , associated with the MJO this Spring and Summer along the equator, sending Air Sea coupled Kelvin Waves eastward toward the central eastern pacific. This subsurface anomalous warmth is what El Niño’s are made of.  I’ll be focusing on this later this spring and summer, sharing with those that are interested via my Dr. Howard and the Dweebs report.

The forecast this week shows, a pattern early in the week with the upper jet mainly to our north. So today Monday should be another nice weather day. Winds will pick up Tuesday as a small system comes through, bringing the chance of some showers. On Wednesday, winds will pick up as well as increasing high clouds. Both the subtropical jet and polar jets do become confluent west of Santa Barbara well off shore. This is a different set up compared to many past storms as the bottom of a large scale trough that is confluent with this upper jet moves into Central California. The front left exit region will favor Northern CA and Oregon while its right rear entry region is focused upon the Central Sierra. Without a lot of subtropical moisture, this set up is not good for a big snow storm moving into the sierra Wednesday night and continuing into Thursday.  This looks to be a light storm, not associated with a Atmospheric River. Thus snowfall amounts will be much less than the storm that brought up to 5 feet along the sierra crest last week. It appears that amounts will be in the 2 to 8 inch range at this time.

One point worth noting, the long wave trough will remain over or near California over the weekend and into the following week. So expect unsettled weather and at least light snowfall on and off through the upcoming weekend.

With the block remaining over Alaska and the Bering Sea, the upper jet is likely to remain suppressed at times into California. So more storms are likely this month….

Wet and Wild Sierra storm moves out of the high country this afternoon leaving another 3.5 to 4.5 feet on Mammoth Mt. AK Block remains in -EPO mode so more storms on the way…..

The Calendar says its April, but the weather says its March.  Another 4 to 5 inches of water fell on Mammoth Pass; over 4 feet of fresh snow over the Mammoth Crest.   Today Saturday is a day where the last gasps of unstable air, ahead of the upper trof axis will come through this afternoon. This evening the weather will settle down….

The forecast for today Saturday is for snow showers this afternoon diminishing by the end of the day.  On Sunday, a flat progressive ridge moves through bringing mostly sunny skies with milder temps. 40s. A stronger but progressive ridge builds in Wednesday

The upper jet redevelops to our north this week. There will be several weaker systems,  bringing mainly wind and clouds. There is a chance of showers from one weak short wave Tuesday….Then…

With a high latitude AK block remaining, (-EPO), it is only a matter of time before another significant storm hits the sierra. That time frame will be next Thursday. It looks like a moderate snow producer. (6 to 18) inches over Mammoth Mt)

Here is what the loading pattern of the EPO looks like. The -EPO is just the opposite.

So in the upper picture, 500z you flip the colors. IE Red on top.  Red is high pressure aloft.

The link below will lead you to a good article on both the EPO and WPO. This teleconnection has been the prime reason for our winter!!

Explanation:

https://www.theweathernetwork.com/news/articles/epo-what-you-need-to-know/43796

 

Still Hanging in there for Chance of Wettest Winter

http://cdec.water.ca.gov/cgi-progs/products/PLOT_FSI.pdf

 

Dr Howard and the Dweebs……………………:-)

Major April Storm headed our way for the weekend…..Pattern may continue for a week to two weeks… (-EPO) then (-WPO)Teleconnection

4/7/2017

Storms Stats:

As of 10:30am 17 inches at Mammoth Weather.com  8200 feet

22 inches at Main Lodge w/ 3.21 inches of water (pretty wet)!

Forecast is for another 1 to 2 feet by Saturday afternoon at the 8000 foot level and 2 to 3 feet over the crest

Sunday look like a Blue Bird Day.

Next wet storm coming in next Wednesday night with a smaller AR.

Remember….California needs all the water it can get!!

Think of it this way…Odds are good that we will not have much of a forest fire season!!

When can you remember a summer without smoke??

 

The Dweeber…………:-)

 

 

 

 

April 5th Update:

Everything on track for an exceptional precipitation event. A moderate AR over the Southern Sierra in April is remarkable!  Winters like 2000, 1988 and 1983 were quoted by WSFO RENO for the Tahoe area. The latest QPF from WPC is 7.7 inches of water in the bull’s-eye over the Southern Sierra by Saturday night. Mammoth Pass stands to receive up to 6.00 inches and the Town of Mammoth up to 3.00 inches.  The snow level currently estimated at 7500 to 8000 feet for Friday is a low confidence forecast as it is not certain how quickly the cold air will get in here.

 

I will update my Weather Letter tonight for Thursday AM.

 

The Dweeber…………………..:-)

 

April 4th:

A weak cold front moved through Mammoth Lakes Monday morning bringing light snow showers over the upper elevations Sunday night and gusty winds over the upper elevations Monday. Following the front, gusty northerly winds developed and cooler temperatures followed. Snowfall was confined to the crest with amounts between 1 and 2 inches. The forecast shows warmer temps ahead with highs returning to the 50s for Tuesday through Thursday and lows in the 20s. An important pattern change is taking place which will be discussed below for the upcoming weekend and beyond.

Latest Precipitable Water Tools from this mornings 12Z GFS show a 24 hour “AR” effecting Central CA and the Central Sierra between 5:00AM Friday to 5:00AM Saturday morning. Water EQ Progs expressing greater amounts for early this weekend. Same model run shows main effects of AR effecting the Sierra between Mammoth Lakes south to the bottom of the Southern Sierra where some 10 to as much as 14 inches of rain may fall on the west side and most weather favored terrain. This may create hydro-problems for the Southern Sierra West Side. Stay Tuned! Although this is just a forecast of a model run, the event is getting closer time-wise.

The prog shows that the San Joaquin River basin may get up to 10 inches of rain according to the new GFS run. This is definitely a serious “AR” now. Well see if this forecast holds through Thursday for the Friday AM to Saturday AM period.  Heaviest precip to occur Friday AM through Saturday AM.   700MB temps fall rapidly Saturday after 5:00AM.

From Weather Letter released Monday:

After a long break in the heavy precipitation of late February and early March, the western hemispheric pattern will resume the trend of the Winter of 2017 of anomalous blocking over Alaska and the Bering Sea later this week. The trend is suggested to continue into the following week and possibly beyond.  Focusing on the same teleconnections as the Dweebs have all winter, the current positive phases of both EPO and WPO will become negative later this week as a return to blocking over Alaska and eventually the Bering Sea forces the upper jet to move south of its normal position into the central west coast. The creates the potential for heavy rain and snowfall for both Central and Northern California. The Global Forecast System shows a forecast of the EPO, (Eastern Pacific Oscillation) in its negative phase some -2 to -2.5 standard deviation’s below normal during the period April 10th through the 13th. The European has the negative signature as well with the “EPO”.  The Eastern Pacific ridge will initially be focused as a subtropical flat ridge near the Hawaiian Islands with more amplification developing upstream near the dateline later in the week. This should allow a moist subtropical jet to precede the weekend storm as the East Asian Upper Jet once again progresses to the west coast. A light to moderate Atmospheric River is expected to affect both Northern and Central California region beginning as early as this upcoming Thursday with high elevation snow with lowering snow levels Friday. The storm could continue through Saturday and possibly Sunday the 9th and 10th.   The European Model has another and potentially stronger AR for the following Wednesday around the 12th during the Fantasy week 2 period. (Not as certain at this time)

This 1st AR will precede the colder portion of the storm, mainly targeted for Northern CA and especially the coastal communities of Central and Northern CA, with a weaker extension into the Central Sierra. Nevertheless, some 2 to 4 feet of snow is possible over the crest by the end of this week.  At this time. The Town of Mammoth will begin to experience the storm as rain Thursday night, with snow/rain mix Friday…Then all snow Friday night and Saturday. It is too early to forecast snowfall amounts in town at this time because it is unknown what the exact snow level will be at this time.

I will update tomorrow Wednesday and Thursday for snowfall expectations for the Town of Mammoth Lakes.

Climate:

The Drums of El Nino are beating again. SSTAs over the Indian Ocean have not been colder at this time since 1986 and westerly wind burst are increasing.  Scientists are being very careful at this time, about any hype about El Niño as they were burned so badly the Winter of 2016.  Nevertheless, this one does bear watching. There is already a major coastal EL Nino occurring along the central coast of Peru causing major weather related issues to that region.

 

WEATHER LETTER:

http://data.mammothweather.com/landing/