Powerfull Mid Pacific Jet Finally making its way into the Eastern Pacific with Strong Winds in the Mid and Upper Levels….Series of storms to continue into the following weekend…..
Wednesday December 10, 2014
Posted at 7:53 pm by Howard
Thursday AM Update:
Just had a peak at the new 00Z ECMWF Control and Ensembles. What is really nice to see and may I add different this year, is that although some storms are splitting a bit as they approach the central west coast, the systems are progressive. The Dweebs certainly hope that the pattern remains active through years end and beyond. This is a different pattern than last year!
Lets chat about the further outlook. There are two distinct short waves that will impact California next week.
1. According to the new ECMWF control….One that will come through the Sierra Monday afternoon, and a following short wave that will dig more down the coast Tuesday night and Wednesday AM. The first may bring us a foot plus and the other….hard to say at this point. Best guess light amounts. There is a 3rd wave for that following Saturday and now another wave the day before Christmas. Remember, strength and timing will be different over the next week or two.
2. Now…lets have a look at the new 12z GFS/X.
a. The model also has two shorts waves, however, the first wave is stronger and has better orographics as the upper flow is SW for a while. However, just after the wave clears the crest the next upstream short wave splits and heads down the coast bringing the west side a glancing shot of snow as well as more rain to Southern CA and Northern Baja.
b. The following Short Wave rolls through Friday PM the 19th. It splits as well, but not off shore according to the GFS, so there is some promise of more snowfall from it. Remember, a split flow is ok as long as split is not on the top of you.
c. There is now yet another wave for Christmas Eve.
Word of Advice. Remember, both the ECMWF and the GFS/X are guidance. Not a forecast. It is the experienced forecaster that has to make sense of it all, usually within 72 hours before the event!
From Wednesday Night: (Current Storm) High Wind Warning now in effect for Mono County through late Thursday Afternoon.
We have already heard most of the hype on this storm. Now lets take a look at other details that will give a different perspective on this first storm.
1. It is slowing down and may not get into Southern Mono County until later Thursday Night.
2. The biggest flaw in this system is the upper flow to the sierra. The upper level winds are more out of the south than SW or WSW which is “less preferable” orographically speaking. So the Dweebs are being careful about going crazy on how much snowfall this system will bring. With that said, it does have a lot of moisture with it…. and “lots of dynamics”. So….1 to 2 feet? no problem; 2 to 3 feet possibly over the upper elevations. 3 to 4 feet….unlikely. With all that said, it will bring a lot of wind and what we need to get it going up on the hill. The best news of all is that there are at least 2 more short waves the following week going into the following weekend. The first two are also orographically challenged. So, 1 to 2 short waves Monday into Tuesday night and yet possibly another the following Friday or Saturday. So with these other systems, we may at the end of “this storm cycle” and end up with four or more feet total….maybe….Lets get the first one in here!!!!
3. To recap timing and amounts…..
The Storm will slow down Thursday south of Alpine County with the heavier snowfall possibly being delayed until after midnight Thursday. IOP will be between 09Z and 18Z Friday.
Mammoth Snowfall Est. Between 1 to 2 feet in town and between 2 to 3 feet over the upper elevations…..
Active Upper Jet Across the Pacific is Moisture Leaden…..Will take Aim on West Coast Thursday…Main QPF to Saturate Northern CA with diminishing amounts for Mono County…..However this system could still dump another 1 to 2 feet up on Mammoth Mtn by Friday Night…..Active Pattern to continue with more storms in Mammoth’s Future the Following Week…..
Monday December 8, 2014
Posted at 12:21 pm by Howard
Models trending wetter……..This looks like a good old fashion Mammoth Storm…..will up date Wednesday,,,,,,,,,,,,,,,
Tuesday AM Update:
Strong Upper Jet of 180Knotts at 300MB will drive the first powerhouse storm in two years into the high country. The system has plenty of moisture and dynamics to dump a good 3 feet on Mammoth Mtn, and between 12 and 24 inches in town. Most likely this storm will be all snow for the Town of Mammoth. Road crews will be busy Thursday night with the highest precip per hour rates coming in around Midnight. Heavy snow to turn to showers Friday Mid Morning with snow showers lingering into early Saturday. After a partly cloudy weekend, another 2 system will bring more snow to the high country….Monday night into Wednesday……It looks like a break after mid week next week…..
A fast Zonal Flow pattern has set up across the pacific as it progresses off the Asian Coast, all the way to about 140West. To the west of Mammoth is an inter mountain ridge that will give way to the belt of Westerlies Thursday. By this Wednesday, clouds will be on the increase along with an increase of Wind over the upper elevations. Snowfall will begin later in the day Thursday with heavier snowfall Friday…… At the Moment, snowfall accumulations look to be in the 6 to 12 inch range for the town of Mammoth Lakes and between 12 and 24 inches over the upper elevations. This begins the next storm cycle with at least another 3 to possibly 4 systems over the following 6 to 10 days. Some will be colder with less snowfall. Some will split and favor Southern CA. Some will give our local area footage. The details as always may be found here at Mammothweather.com.
In that the main Bull’s-eye of moisture is still Northern California and the Pacific Northwest, it is considered more of a normal precipitation pattern for the west coast and not ENSO related.
That may still change in January…..
Comparing both the ECMWF and GFS, the QPF with the GFS is a little drier then the EC….However, not enough to change the Dweebs thinking of 1 to 2 feet over the higher elevations. There looks to be a break with improving weather toward fair WX later Saturday into Sunday. However, the winds will come up again later Sunday afternoon over the crest and develop over the lower slopes later that night into Monday AM. Snow looks likely to return again sometime during the day Monday next week. That system will weaken as it comes and split Tuesday. The opportunity for some moderate amounts of snowfall looks good. This is the timing of the new 12Z ECMWF as of 1:12 local time Monday.
The Dweebs see yet another system the following Friday the 19th.
The timing for all system systems next week are subject to change of course……..
Dr Howard and the Dweebs…………………………….:-)
Moist Westerly Flow to offer Variable Cloudiness for the Central Sierra…..Weak splitting systems to dust the upper elevations with Light Snowfall…Upper EAJ to return later next week……
Friday December 5, 2014
Posted at 8:09 am by Howard
Brief Update shows a retraction to the EAJ to the west coast. However…..weak ridging and areas of clouds and moisture will continue flowing through the high country. A couple of weak splitting systems may bring a dusting to a few inches of snowfall…mainly to the upper elevations tonight and again Monday. Next Storm cycle next Thursday. High temps will range in the 40s with lows mostly in the upper teens and 20s…. No strong winds expected for the lower slopes the next 5 days…
A more detailed update early next week…..