Archive for May, 2015
Winds Picking up as expected…..Breezy tonight….However stronger winds expected Monday as secondary stronger jet moves west to east to the north of Mammoth…..It will be cooler as well……Interesting change to pattern later next week with upper closed low and spun up jet from Andres……
Sunday May 31, 2015
Posted at 3:08 pm by Howard
The GFS this morning has come over to the thinking of the ECMWF…..to no surprise, for weather system next Thursday and Friday! Nice phone discussion with Retired Lead Forecaster. Tom C. on the matter. Tom stressing upper jet dynamics rather than to look solely upon moisture advection from Andres. The Dweebs took a look at both the GFS and EC 12z runs. Clearly the GFS is most interesting with a Trof that comes in more positive tilt a little further west and allows the upper jet to spin up better. The 12Z Run was a little slower as well. The timing is this Thursday through the weekend. Don’t get me wrong…their will be a chance of rain and thunder with both scenarios, but the T-1534 15Km looks more interesting.
With discussion with Tom, stressing more focus upon dynamics vs. just moisture advection from TS Andres. The 1st upper jet spins up very nicely with the aid of latent heat from Andres. Some moisture advection probably warranted but focus upon Upper Divergence and Deformation over the weekend will be the key. With the Subtropical upper jet in place over Southern CA Friday and Saturday and upper cut off near San Luis Obispo , the next Jet-let dives into the base of the upper low late Friday night and couples with Subtropical jet Saturday AM with stronger Upper Divergence over So-Cal. It looks like a fun system to watch develop!
Just as a somewhat unrelated observation, the tropical and subtropical eastern pacific appears to be way ahead of schedule time wise with hurricane season this year no doubt due to El Nino. This is going to be one Fun Meteorological Summer! 😀
In the header above, I made mention of a cool down about the Middle of June. Today I believe that it is going to occur sooner, and I will show and tell you why. In the discussion below, there is reference in regard’s to the RMM phase space that deals with Tropical forcing. The MJO, “Madden and Julian Oscillation” Phase Space chart is spiking with a very significant signature over the Indian Ocean over the next 10 days. The CPC last Tuesday indicated that they did not believe that the MJO itself was causing the spike, because for 1, the MJO is not all that strong this time of the year and #2, if I am correct, the speed at which it is moving. It was indicated that the rise in convection was more due to the low -frequency state of either an Atmospheric Kelvin Wave or the ENSO state itself. No matter, this strength of amplitude and convection over this particular area of the Indian Ocean should cause the PNA to Flip Negative with a long wave Trof setting up along the west coast by early Week 2. That means cooler then normal temps over CA , wind and a chance of precipitation around the 7th to the 15th of June.
Look at the Current MJO RMM, then the composites for June in the forecasted time frame.
RMM; (MJO Phase Space): http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ECMF_phase_51m_full.gif
The Dweebs will update on the progress of all this, once the global model ensembles really latch on…
Dr Howard and the Dweebs………………………….:-)
Roasty Toasty Weekend Saturday with Strong Zephyr Sunday PM….Dry for the Sierra until Further Notice……MJO Phase Space is showing a lot of Amplitude over the next few weeks……Could be sign of a Cool Down by Mid June…..
Friday May 29, 2015
Posted at 10:57 am by Howard
Warming trend in process with highs the next few day in the 70s in Mammoth. A short wave of low pressure aloft will kick the Mono Zephyr in high gear Sunday and so it will become very breezy locally. These winds will blow into the night Sunday and possibly Monday as well. Lows temps over the weekend will be in the 40s.
Interesting News From the CPC:
The Enhanced Convection from El Nino over the Eastern Pacific and Moisture from this Enhanced Pacific convection interacted with the extratropical circulation in the northern hemisphere and resulted in enhanced precipitation across the southern continental U.S. resulting in flooding rains in Texas and Oklahoma.
5/11 to 5/17
San Diego was 800% of Normal; SW AZ as well.
5/19 to 5/25
Precipitation was between 600% and 800% of Normal over the White Mts to the east of Mammoth Lakes near the CA/NV Border.
Want to see real a ENSO coupled index?
Check out the SOI: http://www.bom.gov.au/climate/enso/monitoring/soi30.png
Anything -10 or below is a sign of significant higher pressure and colder water near Northern Australia northward. Strongest convection is now developing over the central and eastern tropical pacific and the Walker Pump has significantly weakened or has reversed direction due to the location of the eastward shifted Tropical Convection.
In the link below, you can see an illustration that shows the Walker Pump and what happens when anomalous warm water shifts east into equatorial eastern pacific. The strongest convective area on earth, “The Maritime Continent”, then plays 2nd fiddle to the Eastern Pacific because the ocean sea surface waters North of Australia and Indonesia cool. Thus it looses it dominance, with a severely weakened trade wind system. The surface air over the colder SST is more dense and of higher pressure and flows toward the Warmest SSTs or area of lower surface pressure…. Thus the reversal of the trades from east to west to a west to east direction. This is classic strong El Nino action in the making….
Now that you understand the Walker Pump System…..Click on the link below and watch the increasing warmth of the SSTs along and north of the Eastern Equatorial Pacific and then watch what happens to the waters north of Australia and throughout Indonesia. Run the loop and watch both the time-lapse from the beginning of 2015 to just a few days ago. You will see the blue or colder water develop north of Australia and Indonesia. The cold water and resulting wind system will act to intensify the El Nino now in place over the Summer and Fall of this year…. SEE: http://www.ospo.noaa.gov/Products/ocean/sst/anomaly/anim.html
The Dweebs have been following the MJO RMM chart:
Have been following the MJO phase space the past few days. It is interesting to note the forecast spike that has been showing up recently for the next two forecasted weeks as it moves through the Indian Ocean. According to the CPC last Tuesday, the spike in convection is probably not a Canonical Madden Julian Oscillation RMM signal. Rather something more related to ENSO and Kelvin waves. There are several KW’s propagating around the globe now. One that has left the eastern tropical pacific and is near Africa or already into the Indian Ocean. The forecasted rise in convection is less likely due to Canonical MJO because the MJO is usually very weak during the Summer months. So it may be more related to low frequency wave systems like ENSO or KW’s. What ever it is….The rise in the RMM chart is very-very interesting!
I will have an update on the MJO RMM next Wednesday….. 😎
MAMMOTH MT CLOSES THE END OF TODAY ON 10 TO 40 INCH BASE…..SEVERAL INCHES OF NEW SNOW FELL AROUND THE HOLIDAY….THE CHANCE OF MORE THUNDER IS EXPECTED WITH A WARMING TREND THIS WEEK……
Monday May 25, 2015
Posted at 9:19 am by Howard
Showers and Thunder brought up to a Quarter of an inch of rain over some areas of the Mono County Crest with Mammoth Pass getting .24 hundreds. Some areas over western NV had 1/2 inch of rain.
There is similar conditions today although the air mass is a tad drier. There appears to be decent CAPE over NE Inyo County and forecasts of 250mb divergence in the same area late this afternoon. So, more scattered thunderstorms along the whites and northern Owens Valley including Bishop looks good.
High temps today in Mammoth today will continue in the low 60s…then rise to the mid 70s by Saturday. It will be hot in the Owens Valley this weekend with mid to upper 90s Saturday and Sunday.
There is a strong short wave that will bring moderate winds to Mono County beginning Sunday afternoon, into Monday. This is a dry systems but it will be particularly windy over night Sunday because of warm antecedent conditions ahead of it. More on this Springtime Northern CA storm later…..
Although there was lots of threatening clouds around Sunday, with few exceptions, little precipitation was actually measured in town. Nevertheless….Mammoth Pass picked up .28, Graveyard Meadows at the 6900 foot level picked up .32 and Huntington Lake .12….. Most of the convection was driven by a combination of solar and 250mb divergence aloft. Today, there is still plenty of moisture around for more late afternoon action, however, it may be a bit further east and north today. Latest SPC shows good -1 lifted’s over the central sierra with best Unstable CAPE along the Mono County NV border from the Northern Whites along the border then up into Mineral County. So the best action may end up building over the Sierra then shifting North then East later today to around the Mono Lake area North to the Bodie Hills then east over the border into Mineral County, Nv.
This Weeks Weather and beyond:
The blocking pattern that has suppressed the westerlies the past few weeks will retrograde west later next week over Asia. This will eventually allow the westerlies to redevelop up into the pacific northwest bringing the return of Springs rains up in the NW or possibly a Mini “AR” later next week. All that while a dry WSW flow develops for the Central Sierra with afternoon and evening dry Zephyr Winds early next week. (Week 2)
Last night Euro Model had the first tropical system (Andres) developing from an easterly wave at about 10N/110West. The tropical depression actually gets picked up later this coming weekend by an approaching short wave moving towards Northern CA under the AK block. As the short wave moves through Northern CA and OR Monday the 1st of June, strong Zephyr drying winds blow through Mammoth Pass beginning Sunday PM and Monday the June 1st. This effectively knocks the top off the heat wave next weekend for the first part of the following week. Early next week will be an especially dry period for Mammoth.
Back to the Tropical System…..The Tropical system gets pulled up as far north 115/20N or on a latitude several hundred miles west of Puerto Vallarta. The Northern CA system heads east and leaves the tropical system hanging over the eastern pacific while the TS helps build a tropical ridge ahead of it as the TS apparently weakens. Then a pattern change occurs over the pacific later next week which allows a strong positive tilt trof to develop NW of Hawaii NE to BC. to the south of the elongated positive tilt trof…..A stretched out Subtropical Ridge between CA and the Hawaiian islands set up then gets pulled apart by that following weekend of the 6th and 7th of June. June 6th and 7th looks very hot for CA.
With the eastern flank of the upper ridge bubbling up and forming the 1st subtropical continental high over the 4 corners states by the 8th….SE flow is suggested off the Continental high. With the remains of Andres” lurking to the south, will have to keep an eye out for an early start to the Monsoon Season at that time.
In the meantime, this weeks weather will still offer a chance of showers and thunder, although it will be less organized than the system last Saturday. Nonetheless, through this mid-week, there will still be enough residual moisture and upper divergence for T-storms, that will develop over the Sierra during the afternoon and shift east or NE into NV. By Thursday, a pretty good Mid level Cap forms, from the first late spring 500MB upper ridge moving into the state. This will suppress T-storms via a mid level inversion, and bring much above temps for the last few days of May. This would result in “low to mid 70s in Mammoth for the 1st time this year. At least low to mid 90s are expected in Bishop over the upcoming weekend.
The last few runs of the CFSv2 has backed off in the Nino 3.4 region from 3.1.5C to 2.8C by next Mid October. The decrease of the .035C should not be unexpected. This model historically over “does it” in the Spring just like it did last year. That is why most climate forecasters like to wait until later in the Summer or Fall to forecast the odds of moderate or strong warm event for the upcoming winter. The ENSO this year at this time is a lot different from what happened during last years El Nino bust. Last years Kelvin Wave did much to get us out of La Nina. However, the warming was too far west to do any good for CA. ENSO last winter was set up much like the winter of 76-77 which was a Modoki. The warmest water was in the NINO 4 region near the dateline instead of south of Hawaii eastward. The +PDO was at a record high for Dec to March. The current forecast for this fall is for the El Nino to peak in the Nino 3.4 region which is where we want it to be. However, the big question is how long it will stay that warm in that region and how warm will it be in the January to March time frame.
This year at this time, we have already have already crossed the threshold into the area of Moderate El Nino territory….Now, Today! The Dweebs believe that this El Nino will grow stronger into the Summer and Mid Fall based upon the guidance. Although we do not know what the upcoming winter will be like as it is still too early, the Dweebs believe that at least through the Fall, snows will come early to Northern and Central CA with a good chance of a few good storms as early as early to mid October, with a wet November and December following. So it is my opinion that a better and earlier start to the ski season will occur this year, even if the actual Winter turns out to be mediocre. The Climate Scientist’s will have better confidence for next winter based upon ENSO later this Summer.
The Dweebs will be watching the MJO and its strength in hopes that it can generate strong Typhoons combined with future strong Westerly Wind burst action over the western and central pacific along the equator this Summer and Fall that would enhance future Kelvin wave activity and support the Nino Basins warmth well into the winter. If this action develops, the Nino Basin will stay anomalously warm until the system breaks down next year and we go into La Nina again….possibly for the winter of 2016/17 or the year after.
Dr Howard and the Dweebs………………………………….:-)