Another Active 2nd half of the week is expected with the potential of more heavy rain Thursday Night into Friday….October rainfall records look to be in jeopardy….

The front left exit region of the subtropical jet is creating the lift this morning to produce some light rainfall in the Town of Mammoth. Once this wave passes we will have lots of clouds the next couple of days but dry weather.  A long wave trof has taken up residence over the Eastern Pacific. However,  too far west for cold enough air to bring snowfall to the Town of Mammoth. Heights remain in the low 570s DM at 500MB, so we are in the sweet spot for rain and tropical moisture but little in the way of snowfall at the 7000 to 8000 foot level. This large-scale adjustment wave will continue to send several shot of energy into the west coast over the next 6 to 10 days affecting the central sierra periodically.  The most significant development is hurricane Seymour off the coast of Central Mexico. This moist system will be moving over colder waters soon…thereby dissipating and releasing its moisture into the surrounding area. With the long wave located at 135 west and a rather sharp short wave progged Thursday AM, no doubt that there will be some heavy rainfall headed for the Sierra Thursday afternoon into Friday AM.  The PWAT from that fetch is forecasted to be as high as 2.00 inches Thursday AM just off the central coast.  Rainfall amounts may tally similar amounts that occurred weekend before last, tying all time October rainfall records for the Central and Northern Sierra.

As far as snowfall, most of it will be above 9500 to 10,000 feet again. At the moment, the OIP looks to be Thursday night into Friday AM.


+SSTA’s are still warmest in the North Pacific. If they remain their, that would lend bias to some mighty cold weather later in December and January.  As mentioned in a past discussion, this is a winter that will be difficult to forecast as the climate models have not done a good job so far.  I would not put .02 cents on any long-range forecast at this time.  As an example Scripps forecasted a “strong La Nina” last Summer and that goes against most climate models now. The PDO as become neutral the past 2 months and there is only speculation on what it will do this winter.  If the Warm Blob backs into the NE Gulf of AK again, there goes our winter. If it remains weak, with anomalous SSTA warmth continuing over the north pacific, that would be more interesting for a normal to wetter than normal winter. The Climate models can forecast all they want but if they do not pan out, they are worthless. Best to stick to the week one and week 2 forecasts and track the MJO for highlighted weather events this winter….


Note; the Dweebs will take a hard look at things later in November to see if there is more consistency in the climate models and at the least, the forecast of the PDO and ENSO.

October Precipitation off to a grand start with 4.03 inches of rain here at the Village at Mammoth over the weekend….For some areas it is the 3rd wettest Oct on record already…..Still lots more time this month to set all time October Precipitation Record……While we wait….Another warm up is in store with temps in the upper 60s Friday…….Is another AR event in the cards for Northern and Central CA this month?

A great storm for the trees!  They need water just like we do. Four inches of rain will certainly help the forest but unfortunately it is too late for many of our giant pines…. Some are now widow makers so be sure to check out carefully around your residence’s. If the’re up wind and dead, get a professional to inspect them and cut down if necessary.

The absolute most dangerous time for tree damage is when we have heavy wet snow that clings to the upper tree followed by rapidly falling temps, and gusty winds.  So if the forecast is for heavy wet snow followed by a quick drop in temps such as after a cold front passage, along with strong gusty winds post frontal….beware! 


This is a different fall. And anything different is a good thing compared to the past 5 years. What is different?  For one, the westerlies were exceptionally strong across the north pacific over the past week.  This was due to the block over AK and the undercutting of the westerlies. Add the tremendous latent heat from not one, but two typhoon’s and Northern and Central California hit the Jackpot! The upper jets strength was spun up more from the tropical systems than cold air advection as is usually the case in winter.

Although we have some fine weather shaping up the next few days….Next week could prove to be interesting and active again. Although no typhoons are expected to become extra tropical over the central or western pacific, the upper pattern does amplify due to a shot of cold air coming off of Eastern Asia. The location of the deepening trof off the North Eastern Asian coast suggest strong amplification of the westerlies downstream with an upper ridge building out at 170west. This is a little west of where the Dweebs would like it to be…..So the upper trof sets up at 140west.   However, in that there is no high latitude block this time, Short wave energy will likely over run the central pacific ridge with time, and either cut the eastern pacific trof off or deepening it SW/NE, which may set up another AR for Northern and Central CA within the next 6 to 10 days…. The AR if it does develop, it does not look as wet or protracted as last weekend. Nevertheless, it may be enough to set an all time precipitation record for October for parts of California and Northwestern NV.

In the meantime, LA is expected 100 degree heat Thursday from a hot *Santana and Mammoth temps will climb into the upper 60s.  All areas will expect cooling late in the weekend with the pattern change expected.  The Dweebs will have a better handle on the prospect’s for more rain or snow early next week or before.

North Pacific Sea Surface Temperatures:

Biggest anomalies are in the Bering Sea now about 170West.  Is it coincidence that the mean pacific ridge is now about 170west?  Is the position of the Anomalous SSTA the Chicken or the Egg?

Also there is a cold pool developing between 160East and 160West, between 40 and 50 north.   Could this be the beginning of the resurgence of the dreaded +PDO?


Stay tuned…….


*Santana = Devil Wind

Wet Windy Weekend expected throughout Mono County…..Main Snowfall will be at elevations above 10000 to 11000 feet….Winds will Increase Tonight…However, for Southern Mono County…The strongest winds may end up being Saturday Afternoon…..Stormy Period to end Monday with the upper jet lifting north next week for a long stretch of Fair Warm Indian Summer Weather….

Saturday morning….


Strongest winds have verified further north with Upper Jet the same.  Although the stronger upper jet has yet to enter CA and is is still on tap for Sunday, the NWS has seen fit to keep winds in Mono County at advisories levels. Plenty of rain is still on the way for Tonight and Sunday…


Friday AM Update:


High Wind Watch hoisted to begin 2:00PM Saturday through 5:00PM Sunday…This looks likely to be the windiest period for Southern Mono County

High Wind Watch in effect from October 15, 02:00 PM PDT until October 16, 05:00 PM PDT


WX Discussion:

A deep upper low continues to sit off the coast of the Pacific Northwest this morning with a strong ~150 to 160 kt upper jet driving moisture from post typhoon Songa into Northern CA. Already some reporting sites on the north coast show over 6.00 inches of rain. This wet fetch should sag southward today with an associated front that will stall out near Fresno, CA tonight. The strong westerly flow, and slow southward movement looks likely to hold off any significant precipitation for mammoth until either late this afternoon or evening. Freezing levels will be high near 11K to 12K and so snow levels for this event will be mostly above 10,000 feet.

Precipitation amounts should range from 1/3rd to 2/3s of an inch by Saturday morning as the first wet swath passes thorough.  Saturday morning looks less likely to have major winds as we are “in-between short waves”. The next wetter AR rolls in later Saturday afternoon with stronger winds as compared to Today. The upper jet will come in just north of Tahoe instead of over Oregon this morning. Precipitation amounts will ramp up beginning Saturday afternoon and heavier precipitation is expected Sunday as the main jet core from the pacific comes in. That jet is forecasted to be 180 knots at 250MB well off the west coast!  WOW for mid October. The track on the new 12z GFS has the axis over RENO Sunday mid morning. It begins to lift north by Sunday PM on this particular model which goes against last nights thinking of it lifting north Monday. This argues against any dusting Monday AM in our town. This 2nd AR is expected to drop between 1 and 2 inches of Precip by Monday AM for our area.


Dr Howard and the Dweebs…………………….:-)






Thursday PM:

Main headline is for the possibility for periods of Damaging Winds, beginning Friday into to Sunday night. The way the Dweebs see it, in that the upper jet axis never really gets into Southern Mono County this weekend, this storm is mostly about wind and rain.  With each incoming Jet Let, we will be in the front right exit region of the upper jet.  Any snowfall below 9000 to 10000 feet will be brief and light over the mountains of Southern Mono County, early to mid Monday morning.

The QPF for the Models over Mammoth Mt are around .50 to .70 Friday afternoon through Friday night. (Freezing level is about 12K)  Another system will bring about an inch of rain Between Sunday night and Monday mid morning. The Freezing level begins about 11,000 Sunday night and drops to 9500 by Mid Morning Monday.

Note; the snow level is usually between 1000 and 1500 feet below the freezing level.

Back to wind:

According to the models, there appears to be several windy periods over the weekend.

The first one is stronger from Tahoe north after midnight tonight into Friday AM.   The 2nd connected jet-let drops to the Oregon/CA border by about noon Friday. That looks much windier for us than the first  jet-let tonight over OR.

By Saturday morning the nose of 180knott upper jet punches into the Bay Area. This particular Upper Jet may be the strongest for our area Saturday afternoon into Saturday night!   Next strong Jet-Let slated for Sunday comes in about 12:00PM and continues into the evening hours, but it may not be as strong wind wise, as the temperature gradient may be less with a little cooler air already be in place. (Well See).

Main concern is for dead trees on windward side of structures getting blown down locally. Wind’s will initially be more from the southwest then become more west to east later in the weekend.  Residents throughout Mono County should do a walk around their residences and look for tall, dead or dying trees and have them removed as soon as possible, as the region is likely to have more wind events this fall.

Dr Howard and the Dweebs……………………..:-)