Omega Block in Place with highly Amped Upper Ridge over California…..February Thaw in Process….Mammoth Mountain Boasts 9 to 14 Foot Base!!
Monday February 8, 2016
Posted at 8:58 am by Howard
It was truly a Super Sunday with near record highs in many areas of the state. Eastern CA will get its chance today and tomorrow with between 5 and 9 degrees of additional warming expected. The temperature forecast for Mammoth both today and Tuesday is 59 degrees with highs near 70 much of this week in Bishop and low 80s in Death Valley.
The Convective part of the MJO envelope is looking like it is leaving the Mid-Maritime Continent north of Australia. The SOI is becoming negative again and this maybe be due to the Upper Divergent area of the MJO moving out of that same area. In the front of the MJO, the Upper “Divergent” portion IE “its convective phase” is expected to continue moving east toward dateline. In the examples below, by using the MJO Phase Space, one can see that it will strengthen in Phase 6 into phase 7 in the NCEP model, however, remains relatively weak in the European. The two CFS examples hold the promise for more precipitation the end of this month. Both the ECMWF and GFS ensemble’s have been hinting of a storm “around” the “18th” of February. However, the short wave will still be coming into the mean ridge position but a weaker one at that.
CFS: 500 Mean Height Anomalies Weeks 3 and 4: http://www.cpc.ncep.noaa.gov/products/people/mchen/CFSv2FCST/weekly/images1/wk3.wk4_20160207.z500.gif
CFS: Precipitation Anomalies Weeks 3 and 4: http://www.cpc.ncep.noaa.gov/products/people/mchen/CFSv2FCST/weekly/images1/wk3.wk4_20160207.NA.gif
It is clear that GFS is much more bullish of a break through of the westerlies toward the end of the month than the European Model is at the moment. The Dweebs suspect that with as strong as the NCEP models are, currently showing this MJO in phases 6 then phase 7 at nearly a 3 sigma, the GFS will probably begin to show the late week 2 period as being very wet over California. However, without the ECMWF being in agreement at this time, one should be cautious about going to the bank on this one until there is more agreement. The NCEP models may be picking up on a tropical storm and not the true state of MJO. That would act to cloak the true picture of the late week two period.
The Dweebs will monitor the strength of the MJO and report tomorrow after the CPC briefing……
Dr Howard and the Dweebs……………………………:-)
East Asian Upper Jet continues to Retreat westward over the pacific with Omega Block setting up this weekend with Upper Ridge building over California……
Friday February 5, 2016
Posted at 8:44 am by Howard
Forecasted warming by models for Mammoth:
+7 degrees of warming Saturday (47); and another +1 for Sunday (48), +3 for Monday (51) and +6 for Tuesday (57). Thereafter, a very slow cool down into the following weekend.
Lows in the teens and 20s….then low 30s by early next week at 8K.
Winds over the crest very light today…They will begin to pick up Sunday Afternoon out of the east and be 30 to 40 mph Monday. Upper flow backs from the SW again Tuesday as closed upper high breaks down. SW flow will slowly ramp up over the crest next week between Tuesday PM and Saturday…..Gusty winds may extend down to the lower slopes by early Thursday…
We may have some light snowfall next weekend to freshen up the base… The storm will probably split, as the mean ridge, although weaker………Remains over the west…..
Sometimes we have January thaws and sometime they develop in February. It is of no consequence as the results are the same……IE A mild to warm dry period. In the case of the next 7 days, it is highlighted by an Omega Block favoring a strong upper ridge over the far west. Over the next 10 days, this is expected to be our mid-winter thaw. Here in Mono Country, the pattern change will allow the local snow leaden tree branches shed, roofs to slide and an opportunity for drive ways to melt. This is also an opportunity for those to get the snow off the eves to prevent ice dams.
As far as the weather goes, high temperatures will climb to within 5 degrees of the record warm spell of 1951 where highs reached into the low to upper 70s in the Owens Valley, (the early to mid part of next week). (Upper 50s in Mammoth Lakes)
If you do not like the pause in winter, you can blame it on the Madden Julian Oscillation (MJO). A phenomenon of tropical forcing that ultimately modulates and demodulates the westerlies by the extension or contraction of the East Asian Jet. When using the MJO composite’s in relation to the time of year, its location over the pacific, with the strength of ENSO in mind, it can give you an increase of confidence of what we can expect, weather wise. This is true some 2 to 3 weeks out in the future. Thus, this inter-seasonal signal is another addition to the weatherman’s arsenal in longer range or inter-seasonal forecasting.
Each global model has its opinion on the strength of the MJO. The European model, as no surprise, is doing a better job this winter during this particular strong ENSO event. It appears to be less confused or has better bias correction in conjunction with the ENSO base state. It performed very well last December in accurately forecasting the extension of the EAJ that resulted in an AR event over Northern CA northward the first week of January.
Although we may have few light to moderate storms beginning as early as the weekend of the 13th, or that following week, the El Nino and the constructively interfered MJO influence for the next storm cycle is looking good for the end of the month and early March.
The MJO is again forecasting the same to happen during the last week of February as it travels into Phase 7 then 8. However, this time seasonally, odds are greater that its impact and focus of the AR will be much further south, like Southern and Central CA. This is because the upper jet is stronger at or near its peak climatically. (As a note; it will be important for the MJO to remain strong through the phase spaces 6 and 7 as depicted by the ECMWF). So that by the time it reaches Phase Space 7, it can do its magic! IE a strong extension of the East Asian jet.
For those that are model watchers; look for:
- After several Gulf of AK storms moving through the mean west coast ridge after the week of the 15th….
- Look for strong amplification and “RETROGRESSION” of the eastern pacific high, over the eastern pacific punching up into AK week 3, possibly resulting in a closed anti cyclone well north over the Gulf of AK.
- This may begin around the 21st of February. (The Dweebs will fine tune later)
- The ECMWF “EPS” has the closed anti cyclone formed over Southern AK on the 24th of February.
- Thereafter, a very wet pattern emerges for the central and southern west coast as the EAJ “undercuts” the closed anti-cyclone over Alaska shortly afterwards, and the excitement begins!
So enjoy the break and get ready for Winters Best!!
Dr Howard and the Dweebs………………………..:-)
Partly Cloudy Unsettled Weather to give way to Sunshine and Warmer Temperatures Friday well into Mid-Week as Pattern Shift gives California a Dry Spell through at least mid-month…….
Tuesday February 2, 2016
Posted at 12:59 pm by Howard
Tuesday AM Update:
Only comments to the forecast is in the outlook. The Dweebs had a look at the reanalysis charts and focused on February of 1951 in which a similar upper ridge developed for a week, bringing record high temps to many areas of CA. The Record for Bishop is 78 degree for the 10th of February in that year. I think that it is likely that Bishop will break into the 70s early next week for the first time this year. Mammoth in the upper 50s is possible.
To our west, Super Sunday will be in the process of a rapid warm up along the coast with 1000/500mb thickness expected well into the mid to high 560’s DM by Monday and Tuesday. Some areas in the SE Bay Area may break into the low 80s early next week with SFO possibly breaking 70 by Monday or Tuesday next week.
The February thaw will last about a week with a change back to an active pattern, around or shortly after mid-month. That is due to the southern stream, as it resumes its promise in keeping the western hemispheric pattern progressive this winter. (See Comments below, (Regarding the MJO)
It continues to be cold in Mammoth with the high temperature yesterday 18 degrees at the FS office, then an overnight low of -7 this morning. Today it will warm to the mid 20s! For those that are uncomfortable with temps this cold, the weekend will be much milder with highs in the mid to upper 40s Saturday and lower 50s Sunday and Monday. It should be an epic weekend with little in the way of any wind except over the crest with NE flow. Lows at night will be in the 20s.
Upper heights will rise in response to the existing trough over the inter mountain west exiting. An inside slider, or “impulse on the storm track” will move through today bringing snow showers and breezy weather over the upper elevations. The upper west coast ridge begins to build Wednesday. However another weakening system comes through and spreads mainly warm air advection over our region for another chance of snow showers Wednesday night. The Dweebs are not expecting much more than a trace of to an inch of snow from either system.
The Big picture indicates that an omega block will develop with the focus of the west coast ridge parked over CA Sunday and over the Great Basin into early next week. The brings cold weather to the SE CONUS as short waves drop out of the upper Midwest early next week and plummet south to the South East. In fact the northern or central part of the state of Florida may have a significant freeze. This looks to happen about the 10th through 12th of Feb.. Will another Nor Easter spin up later next week around the 8th-9th?….Will see.
Last time it did we got a storm 10 days later……
According to the EURO, the MJO is forecasted to become quite strong again emerging over the western portion of the Maritime Continent and strengthening over the Eastern Maritime continent with further strengthening over the Western Pacific, late week 2. The positive phase of the PNA should either block or weaken storms approaching California Through at least next week. The ECMWF did an excellent job with the last MJO rotation through the phase spaces. So the Dweebs are bullish that it will work out well again.
Here is the trend;
- Weak MJO (Tropical Forcing) Emerges this week in Phase 4 through the 8th of Feb. (Ridge building along the west coast with the establishment of the Omega Block by this Sunday/Monday)
- Strengthening occurs in phase space 5 and 6 and remains strong into phase 7.
- Toward the end of week 3, the ECMWF has the MJO forecasted to move from early into phase space 7 then into 8. That is when the return of the true El Nino forcing is expected. Mark your calendar for the week ending toward the 18th of February through the first of March. This looks to be a very active 2 week period. It do hope it includes Southern CA as well.
Dr Howard and the Dweebs……………………………..:-)