Some unstable air to bring Showers Wednesday followed by a fair warm Friday and Saturday……Late Season Storm Possible as MJO now strongest in Phase 7/8 in several years modulates the westerlies during week 2…..Moisture from Surigae may be entrained…..

Thursday 4/22/2021

Quick Update about weather changes this weekend and Fishing Opener…

  1. No wind advisories expected for Mono County Saturday, however, SW winds will come up overnight with gusts 15 to 30 MPH with stronger gusts expected in the late morning and afternoon.   It is likely to be choppy out on Lake Crowley, however, at this time, not a significant wind event…..Saturday will be dry…..
  2. Sunday is expected to be cold and snowy with gusty winds.  Snowfall amounts will be a good 12 to 18+ inches on Mammoth Mt, by Monday.  Even the town could have between 5 and 8 inches. However, the roads are warm and it will take time during the snowfall for them to freeze up. When they do, they will become very very icy!!!!  So slow down when driving Sunday night and Monday…

More later….

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4-20-21

9:38AM Update:

  1. Typhoon Surigae was the strongest typhoon in the month of April in the Western Pacific. strongest sustained winds of (190 MPH) At one point, its winds increased 105 MPH in 36 hours!  Went from Cat 2 to 5.  Wind Waves up to 75 feet were observed. The Storm is in its weakening phase now and will begin to turn toward the NE/E this Thursday AM as it winds down. Moisture from Surigae will get picked up by the westerlies. Storm becomes extra tropical this Thursday as it rapidly looses its moisture to the westerlies.
  2. MJO is still in Phase 7 and forecasted to cross into Phase 8 by this Sunday.  As suspected, a formable Kelvin Wave has formed east/west of 120E. Westerly wind bursts are continuing over the western pacific.
  3. SEE:  http://www.bom.gov.au/climate/mjo/#tabs=Time-longitude  
  4. At the moment, moisture from Surigae is forecasted to lie, well to the north of the Hawaiian islands this Sunday. It appears that the Sunday-Monday system will have a small tap of subtropical moisture to work with, bringing possibly a foot+ of snow to Mammoth Mt Sunday Night and Monday. The real AR associated with Surigae is coming in, in back of that 1st storm.
  5. Here are the unknowns at this time.  The depth of the second storm for Thursday the 29th will have the “Potential” to bring a lot of precip to portions of the west coast. Odds are, the main thrust will be to the north of us, as the global models lift the upper jet into Southern Oregon. However; AR moisture usually flows in under the upper jet. Thus Northern CA may do quite well. This AR is rather broad by Thursday AM, the 29th, extending from Northern CA to Central CA.  Its strength at extension eastward beyond the coast is somewhat questionable at this time.  I think that all of this is subject to timing. The variables involve the upper high over AK and how fast it shifts west to Eastern Russia.  At the moment, the global models have the upper high over AK this Sunday. That is good positioning for a large scale Trof for into CA. The next storm is the one that carries the bulk of Surigae moisture. It arrives Thursday the 29th with the Subtropical Jet into Central CA.  500mb Heights and 500mb/1000mb thicknesses are fairly high so snow levels will be too.  This is all a week+ away. So lots can change.   The best part of all this is that we have good support from the MJO and its composites.

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It will be a beautiful day today in Mammoth with highs in the low 60s….Later Tuesday into Early Thursday….A couple of weak systems of low pressure will combine with daytime heating to provide the chance of showers with snow showers in the upper elevations. Expect fair weather Friday and Saturday with warmer weather….lows 20s, highs in the low 60s.

MJO strong in phase 7 and expected to remain strong into Phase 8.  This presents an interesting Conundrum. The puzzle is in regards to the forecast so late in the Winter/Spring rainy season, especially one that has been so dry.

The MJO; Madden Julian Oscillation is a formable modulator of the westerlies, especially during the winter season into early March. (OLR) Outgoing Longwave Solar Radiation near the dateline was weakened dramatically this year, due to stronger than normal trades this past Fall and Winter; associated with LA Nina. Looking at the Hovmuller OLR time series; (https://ncics.org/portfolio/monitor/mjo/) select OLR mode, you can see the absence of OLR near the dateline (shaded in Brown) all Winter, up until early April. Just to the West, there was strong OLR stationary about 140E.  The stronger than normal, lower level easterly winds of La Nina have concentrated the warm water, warmer than normal in this region. Once the MJO pushed into that region, it spawned the second strongest Typhoon on record in April, now near the Philippines. Looking at the MJO phase space; It shows the MJO remaining very strong, now in phase 7, into phase 8.  This transition geographically, at this strength has a significant teleconnection to west coast weather in the Winter. However, it will be late April by the time it is in Phase 8. Will the EAJ extend to the west coast?  Will there be an “AR”?

This is going to be quite interesting, as to if the East Asian Jet gets modulated to the west coast.  Additionally, there will be a ton of moisture from the remains of Surigae, that “May” get entrained in the upper flow, and find its way to California the end of this week.

Super Typhoon Surigae,  just missed the Philippines. Surigae had/has winds of at least 185MPH as it was or is a Cat 5 storm.  The Storm is recurving to the north now and then eventually east…..Lets hope it all comes together with beneficial rains to our state, about Sunday, Monday and Tuesday!

 

Dr Howard and the Dweebs……………………..:-)

 

Chilly Upper Low over the Far West expected to bring light snow to the High Country Wednesday before Exiting Thursday……Fair Warmer weather expected for the weekend…

It was quite the windy day across Mono County Tuesday as an area of low pressure deepened along the Northern CA/NV Border. Winds were clocked above 60 MPH in the mid afternoon in Bishop. The High Wind warning well advertised by the NWS nailed it!  Cold Air advection poured into Mono County during the Mid Afternoon.

By Wednesday morning, the upper center will be near Tahoe before tracking east through Nevada during the day. As the low shifts east, an area of baroclinicity will drop south Wednesday morning initiating the chance of snow shower’s. By the afternoon Wednesday, the WRF model has the upper center very near the Utah Border, while a rather impressive Vort Center swings SE from west of Tahoe to Mammoth During the Mid to Late afternoon hours.

This Vort center is coming through during the period of max heating and instability. So it could get kind of wild with areas of Snow Thunderstorms later in the afternoon throughout the county including Mammoth Lakes. Snowfall amounts could be several inches in some areas with the snow level about 6000 feet. Precipitation will wind down by Mid Evening…. Highs will be chilly…In the low 40s… Lows in the upper teens and twenties Thursday AM.

 

The upper low exits quickly Thursday morning with a sunny day expected. High temps will be near 50 with a warming trend.  The Weekend looks stellar with temps warming to the low 60s by Sunday!

MJO: Attended the CPC Tropical Discussion this AM

Changes are coming to ENSO as a robust MJO now over the Western Pacific shifts east across the pacific the next two weeks. Strong westerly wind bursts are occurring ahead of the MJO and an air/sea Kelvin Wave is pushing warm water east over taking the cold La Nina waters. This MJO is expected to put the nail in La Nina over the next month or so.

With MJO in phase 7, the composites suggest warmer than normal weather next week with dry weather continuing.  However, the MJO remains strong into Phase 8 and that suggests that another change in the pattern may return precipitation chances to the Sierra, during the last Week of April!   Where was MJO in Phase 7/8 in February!   That time of the year, a strong MJO in phase 7/8 can bring pounding rains and snows for California and the Sierra. However, not this time of the year…..Although we may get a late April Surprise………………..;-)

Start thinking about water conservation now, as its going to be a rough Summer for California.   We can only hope for lots of wet Thunderstorms for the high country.

 

Dr Howard and the Dweebs……………………………:-)

 

 

Breezy Weather with above normal temps to continue into the weekend….Possible pattern change middle of next week

It’s that time of the year again. Breezy afternoon and evenings are likely to continue for some time as we remain sandwiched between a subtropical ridge and trofing to our north.  The upper jet is split too with the northern branch sending short wave trofs into the pacific NW and northern Rockies.  Each one of these systems increase the gradient.  Height rises this weekend will serve to increase our temperatures. Highs that have been running 57 to 58 degrees will bump to the Low 60s, Saturday into Monday. Lows at night of late have been in the 30s due to nighttime light to moderate wind. It may cool a bit Saturday AM into the upper 20 as winds will diminish a bit.

The Main features affecting our current weather is being fed by a Polar Vortex along the north coast of AK. This Negative tilt extension is bumping up against a subtropical ridge at 18000 feet. (500MB) The result is above normal temps and wind in the high country.

Over the next 7 days, this PV resets south of the Bering Sea and the result is a positive tilt ridge into Western Canada. The return flow over that ridge may dig a trof into the Great Basin toward the middle of next week.  That pattern would bring cooling, wind and the chance of some light snow.  Now, the NWS is going with persistence through mid week next week, as there are not enough ensemble members to challenge the sensible weather pattern we currently have.

Looking at the MJO phase space, it shows a robust MJO moving into phase 7. This suggests that our exceptionally warm weather may not last beyond early next week. It also suggests in its composites, this time of the year, precipitation over Northern CA later next week.   So, odds for a change in the pattern is being supported by the MJO for at least cooling out west.

As many have heard, we are expecting an increase in drought conditions out west.  However, the ECMWF climate model shows a more normal Monsoon Season in July and especially August. This typically does not help CA, but may bring some relief to AZ and the rest of the Desert SW.

Above normal temperatures are expected July and August and high temperatures may hit 90 degrees at least one day in Mammoth this Summer, about mid-July. With more normal or even an enhanced monsoon, comes the possibly of more thunderstorms. The Peak of Thunderstorm season in Mammoth is late July and early August.