Major April Storm headed our way for the weekend…..Pattern may continue for a week to two weeks… (-EPO) then (-WPO)Teleconnection
Tuesday April 4, 2017
Posted at 7:36 am by Howard
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??
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.
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.
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.