The Calm Before the Arctic Bowling Ball Upper Low…..Beautiful Weather with Highs in the 40s….Good Set Up Tuesday Afternoon and Night for Lake Effect Lee Vining Dumper!
Sunday December 28, 2014
Posted at 3:36 pm by Howard
So Far No Lake Effect for Mono Lake Communities Lee Vining or Mono City reported…..
Temperature and wind conditions favorable for it, however no surface convergence/250MB couplet. Well see what happens tonight….
Coldest portion of Arctic Air Mass over us this evening up until midnight, but temps will change little Wednesday. It will be colder Wednesday morning…
No clear idea on extended for the following week as far as a storm…
Finally some warmth! Highs today climbed into the 40s with Sunshine and light breezes over the lower elevations while the upper elevations were seeing stronger gusts. Our Arctic Front is on the way for Tuesday.
Here are the highlights and comments in regards to this system:
1. It is cold but not a record breaker.
2. The lack of snow cover over Northern NV will take some punch out of the system.
3. It will be windy over the upper elevations but northing exceptional. IE 70mph to 90Mph winds in some areas near the crest.
4. Although it is a no a record breaker, the models have 700MB temps near -20C early Wednesday AM for our area. 500MB temps are in the -30s that sometime.
5. The models usually under forecast the precip for the sierra with a system like this. The QPF shows a 5 day total of about .25. With snow to water ratios greater then 20:1 on Wednesday, Should the deformation zone set up over southern Mono county, we could pick up more then the 1 or 2 inches predicted. It looks like it will set up more over the Northern Owens Valley and so parts of the Valley may pick up several inches of Snow between late Tuesday Night and News Years Eve. Again, this will depend upon the actual track of the low, how fast it moves out and where the deformation zone sets up.
6. Now here is want looks interesting…. Looking at the 850MB heights/RH, the iso heights are really packed up against the Eastern Sierra. Temperatures at 700MB are -19C and -9C at 850MB. the RH is 80% to 90%. Light NE Flow at those temperatures spell the possibility of some Excellent Mono Lake Effect Snow Conditions that may effect Lee Vinning and possibly June Mtn, Beginning later Tuesday afternoon through Wednesday Mid AM.
I am still seeing the consistency in the longer range for a break through of the Westerlies. However, it is too soon to get excited as the event begins about a week from this Wednesday.
Happy New Year From the Dweebs……The Cold Northerly Flow Aloft has shifted East a Bit…Temps have rebounded nicely in the High Country…..Next BC, Clipper will Tap even colder air as it dives south down the coast the next few days……Tuesday/Night/Wed will be Brutal Temperature Wise…..Long Range Models still hinting at Under Cutting By 2nd weekend of January..
Thursday December 25, 2014
Posted at 9:35 am by Howard
Saturday PM: Attn. Condo Managers
Just looked at the new 12z ECMWF 700MB temps. The EC shows between -18C and -19C at 06Z Wednesday (Tuesday night). That’s about -2F on the Mountain in free air. Tuesday will be very cold with a wind chill factor over the higher elevations. By Wednesday AM temps will be well Below Zero in many areas of Mono County that are wind protected.
In short term, QPF models could easily underplay snow amounts on “bowling ball” type vort max and low track directly south along or just to west of Sierra crest on Tuesday/Wednesday. These are calling bowling balls because of there shape and are heavy hitters with QPF as opposed the the ligher northwest sliders or back door fronts which “brush” quickly through the area. QPF models down play most of these north to south system because the cold advection term in the QG Omega equation results in weaker Omega or UVV…however this is often negated by slower moving lows and deformation zones along with more instability due to the cold pool aloft and possilby better orographics. Stay tuned.
Week two Ensemble and control of the global models are all either suggesting or hinting of an “AR” type event in CA around the 2nd week of January. The Arctic infusion ahead of the WSW Flow makes sense so will take it more seriously. This possible “AR” event in California’s future will be the talk of the town the next 6 to 10 days….. I for one will not get all that excited until its on our door step….. Remember, the split flow blues?? Yea it’s on my mind….
A short wave ridge of high pressure will bring warmer temperatures today with highs in the upper 30s. It will be mostly Sunny and dry. Temperatures will reach 40 degrees on Sunday. Nights will actually be coldest below 8000ft after midnight as compared to the upper elevations above the inversion.
8000 ft low temperatures will be in the low 20s. Low temperatures will range down into the single digits and teens over the lower elevation valleys between 7500ft and 6500 ft.
The next system for early/mid next week does not have any over-water trajectory for the upper low itself. So only light snowfall is expected early Tuesday morning into New years Day. This is an Arctic system with the coldest air so far this season…. Highs in Mammoth will be in the low teens on Wednesday, New Years Eve Low temps most likely below zero.
Note: At this time it is possible but unlikely that the Owens Valley will have any heavy snowfall as the upper low itself is forecasted to remain on shore. (No moisture tap) So light snowfall and accumulations are still in the cards…..possibly an inch or two. I’ll update on this Sunday….It will go either way by then….
The Next Storm Cycle looks to be in the 2nd week of January…
Have a Happy New Year!
Merry Christmas from the Dweebs…..Weather to turn blustry later today and tonight as Chilly NW Slider moves in quickly this afternoon….WX Pattern to Become More Amplified Next Week with Insider Slider Pattern likely…..
Wednesday December 24, 2014
Posted at 12:53 pm by Howard
1:53PM It’s Currently Snowing in Mammoth Lakes!!
Most QPF models are pretty much the same, calling for about 1/2 inches of moisture for this area of the Sierra. However, HPC is touting an updated 3/4 of an inch for the crest, Day 1 QPF. HPC has a habit of being a little on the “Wet Foot” side, so will stick with initial snowfall amounts of up to 8 inches over the crest and hope for more.
That means that the Town should be in for a good 3 to 5 Inches overnight. With that said, CRFC is calling for a 1/2 inch of moisture in the Yosemite area. With a system with Orographic’s like this one, the Dweebs will often times double that for the water EQ. Now …..in that most of the snow will fall after the cold front, “FROPA” in the colder air; And…..considering snowfall ratios are expected to average 13:1 to 14:1, we may end up with a present surprise Christmas AM in the upper elevations of more snowfall than expected or even the town..
Next week the upper air pattern with really begin to amplify. At the same time, some retrogression will be under way. The eastern pacific ridge wants to slowly retrograde to about 135W to 140 West. This location, this amplified, this time of the year, can bring some of Mammoth Coldest weather. The Dweebs would not be surprised to see below night-time below zero temps developing around the New Years Holiday. At this point in time, it is not clear of the storms track and if the systems will be either inside sliders or outside/coastal sliders. Several ECMWF and GFSX ensemble members have shown the development of an Modified Arctic Upper Low that develops over Northern CA and drops south about the end of the year or within the first week after. The location of this system will be key to snowfall here in the Eastern Sierra. Additionally, folks in the Owens Valley will need to follow the weather later next week as if this cold system as cold as it looks gets close to the coastal water of Paso Robles or Santa Barbara, this would have the potential of pumping a lot of snow up the Valley.
Comment: This is not a forecast at the moment, just discussion on the possibilities……
Dr Howard and the Dweebs……………………..:-)