Archive for September, 2020

Smoke for Creek Fire to Retreat again Thursday….Upper Ridge Breaks Down this Weekend…..Slow Cooling Trend Next Week…..Slight chance of showers by Thursday the 8th…..Windy Cooler Weather to close out next week…..

Wednesday 11:10 AM:

Smoke rolled in Tuesday as expected. Expect another day of poor air quality today Wednesday.  This high pressure system aloft, (upper ridge) has been behaving in a manor that gave Northern CA strong east winds Sunday, NE winds to the Eastern Sierra Monday.   The upper high has two lobes.  Sunday and Monday the emphisis was on the northern lobe, where by the Eastern Sierra had east winds.   On Tuesday and again today Wednesday, it is the soutern lobe over or near AZ, that had higher heights, of which light southwest flow was enough to bring smoke back into our region. The northern portion will once again strengthen and overtake the south. This will allow ENE flow to redevelop over the Eastern s

Sierra and help to clear our air as the upper flow pushes the smoke baclk over the crest to the west.  The upper low is pretty weak Frday and so the flow kinda moves back and forth between SW and NE.  The overall effect may be that we might have some haze early Friday that would be cleaned up later in the afternoon, bit hard to say. By the weekend the upper high breaks down. The upper center is over Central CA. There will be little upper air movement.  So there may be some haze, but should not be a huge problem if the current model projections are correct for the air quality this weekend.  The Creek Fire reports at this time were 24 hours old.  It was some 10 to 12 miles from Mammoth Lakes. The report said that It was not progressive, as it was burning into Granite and into the old Lions Fire burn Scar. (Creek Fire; Over 305,000 areas burned)

Next Weeks Weather and Beyond…………

The idea with this mornings model runs shows a gradually break down of the strong ridge pattern over the far west, beginning this weekend, then into early next week.  Temperatures will still be above normal through at least Tuesday. However, they should pull south of the 70s by mid week. Normal highs in Mammoth in early October are in the low 60s. The Dweebs expect some SW flow early next week which will strengthen a bit by Thursday. They may mean smoke for us.  On another related subject, Hurricaine Marie, now well south of Baja will move northwest and weaken next week. Moisture from the remains of that system is progged to be picked up by a weak trof of low pressure  This moisture may make it into Central and Northern CA later Thursday the 8TH, and Friday the 9th of October. This mornings 12z GFS run showed precipitable water increasing Thursday and Friday from the coast inland.  At this time, there is about a 20% cance of showers early Friday AM the 9th.

Beyond the 9th, there is a much stronger Trof moving into the Pacific NW Saturday into Sunday the 11th. We are south of the upper jet which at this time is progged into Oregon Sunday.  Depending upon future runs of the Global Models, it is possible that the upper jet may sag as far south as Northern CA, as there has been a few runs of the GFS showing that.  The upper jet off shore at 250MB is nearing 155knots.  The front RT quad of the jet is over Northern CA later Saturday into Sunday.  At this time of the year, there is quite a bit of warmth over the deserts. The warmth and most importantly the antecedent warmth that is pre frontal, can lead to a strong wind event throughout the Eastern Sierra in the Fall, when the upper jet is northwest over Northern CA. An appraoching nose ahead of a 140 to 160knot jetlet can play havoc in both fall and mid spring.  The Dweebs main focus will be that pattern the weekend of the 10th and 11th.     Stay tuned!!!

Although the opperational runs had the upper jet over Oregon this AM, (Not as windy) The transisition period from September into October often times underplays the strrength and position of that upper jet at 250MB.

The Dweebs will take another look at the guidence early next week……

In the longest range guidence, (fantasy Land) The global models bring in another stronger wave of low pressure with yet another strong upper jet. 500MB hights suggest the possibility of showers from that system with possibly the 1st dusting.  This is in the relm of what meteorologists call Fantisy Land. The Dweebs are not putting much faith in it yet. If it still shows up in another week, I will take and give note!


Dr Howard and the Dweebs………….

Beautiful Clear Day Monday will Give Way to some smoke Tuesday….Then Better Air Quality Wednesday…..PNA Pattern to break down this weekend, leading to better weather for the fire fighters

9:45 PM Monday

Monday nights Rapid Refresh Smoke model really pushes the smoke back into Mammoth during the afternoon hours Tuesday….More hacking and coughing ahead….


The highly amplified pattern across the pacific and North America, responsible the for heightened fire season is still in play.  This is actually +PNA Redux. Its a very similar pattern that developed back in early September, when the Creek Fire started. The late August through early September +PNA that developed was epic in strength, as far as positive height anomaly over CA. (601dm) for those dates.  It was truly a hybrid between the Eastern Pacific High and the Subtropical Contential High at the time.  The net result was a small upper jet that developed along the western flank of the upper high along the CA Central coast. It moved up the coast and set off a lightening storm that the Bay Area and Northern CA will long remember. That storm was respondsible for the fires along the Central and Northern CA coasts.

The current pattern is minor in comparison, but is still similar in some respects. The main height anomaly is further north, so Mammoth does not get the heat, The strongest winds are over Northen Ca and are respondsible for the fires over NAPA and north. It should be noted that, the down stream effect is a cold eastern trof that the east is dealing with.  Additionally, meridional flow is playing havoc in europe with very chilly temperatures in the Alps and France.

The Current highly amplified pattern of ridge/trof, (+PNA) will break down this weekend.  By Monday a week away, a strong belt of westerlies pushes into British Columbia. Underneath the westlelies, California is still under fairly high heights at 500MB, so temps are likley to remain a bit above normal with highs in the low 70s by Monday. Lows in the 30s. With any westerly flow, well likely get smoke from any fires that are buring to our west or SW.

Looking at the ECMWF Weeklys; (long range) looks drier than normal right on through October.  It does show some polor jet related storminess the first half of NOV.  I usually take this with a grain of salt as climate models do not do very well in September and October.

Some minor changes in the ridge pattern will allow Signifacant smoke back into Mammoth Tuesday. The upper height anomaly splits in half with slightly higher heights to the south. This will be enough to create light SW flow Tuesday and import some smoke from the Creek Fire back into Mammoth. By Wednesday, higher heights once again develops to the north and the flow backs again to the NE, later in the day Wednesday. That will tend to push the smoke back west again late in the day Wednesday. Overall,  Still looking for a very warm remainder of September/Oct week head. Not much change through the middle of next week as well. However, the GFS is showing some subtropical moisture moving into Central and Northern CA about the 9th of October. That may bring some light rain to our area.  Updates on that next week.



Dr Howard and the Dweebs…………………..:-)

Summer goes out on a quiet note and Autumn Equinox arrives at 6:31 AM Local time Tuesday…..Some Increase in SW breeze this week then Quiet weather Wednesday and Thursday with more breeze Friday……Another heat spell on the Horizon…

The Tempo really picking up in the long range with potential for record high temps early next week and more critical fire weather, Beginning Sunday and well beyond…….See discussion from two days ago below.


Today is the last full day of Summer.  Like many days of 2020, I am looking forward to getting on with the Fall and Winter.  Cooler days and eventually Snowfall will put an end to the Smoke from the Creek Fire. There is no telling how many people have been affected by the long term effects of the smoke and hazardous air quality throughout Mono County This Summer. Those PM 2.5 smoke  particles are toxic to everyone.

The first couple of days this week are highlighted by the effects of Trofing in the GOA and Pacific NW. Expect more SW breeze today and tomorrow Tuesday with a fairly Calm Day wind wise on Wednesday. No doubt that there will be more smoke from the Creek Fire…..Early this week.   For Wednesday, there is a small upper high over the top of us bringing us a warmer day. Another Trof moving into the Pacific Northwest Thursday will bring an increase of wind Thursday afternoon into Friday. This does not look like a wind event. We could still have winds in the 25 to 35 MPH range.


Longer Range:

The Dweebs are watching a tropical storm in the western pacific #14. The global models spin up this system later this week, and constructively phase with an approaching trof coming off Asia this weekend. The down stream effects are;  amplification of the downstream upper air pattern with a deepening Trof just east of the dateline and strong ridging in the Eastern Pacific. This ridge is progged to  build into California later Saturday into Sunday and Monday.  If this scenario sets up, it may be similar to early September when hot temperatures developed over CA. This pattern is not as extreme for CA as early in the month as it will be late September and early October by then. Nevertheless, Offshore flow (Santa Ana winds) are indicated and hot weather will develop again in parts of the state and especially Southern CA. Sunday into Tuesday, the end of the Month. “This is an outlook at this time, not a forecast”


Upper 70s or low 80s in Mammoth may be in our future next week….Nights will still cool into the 30s..


Dr Howard and the Dweebs………………:-)