Archive for August, 2014
The Month of August to end on a quiet note…..The Outlook is for more of the same with the week beginning with above normal temps then slightly cooler the 2nd half……It looks dry for the next 5 to 7 days….
Sunday August 31, 2014
Posted at 4:43 pm by Howard
SEE: Comments of ENSO today at Bottom.
A stable dry northwest flow across the eastern sierra will continue the trend of sunny days and cool nights. High temps will warm a few degrees between Labor Day and Wednesday. Zephyr winds will range between 10 and 20 MPH. After mid-week, a weak broad trof will provide some cooling…..down to more seasonal levels with highs in Mammoth returning to the low 70s. This is in comparison to the next two days with highs near 80. Nights now in the 40s will trend down into the 30s later this week…..
With the night times now longer, and our air mass quite dry, there will be a longer period of radiational cooling, enough for lows in some areas to get well down into the 30s. A north/south surface gradient will develop by Mid week and produce about 5 degrees of cooling by Thursday. Thereafter….a light NNE surface gradient will remain through next Sunday.
This looks like an excellent week for back country travel……………………
It will be a dry 5 to 7 day period ahead……
The CFS has been back peddling on the idea of significant precipitation mid-month. Now is trending with some precip in mind more toward the equinox. There is still a lot of warmer than normal SST’s off the coast of Baja and the Sea of Cortez is very warm. A TS coming up any ware in that area would hold together long enough to bring heavy rain to Southern CA and especially AZ.
ENSO: El Nino has yet to develop……with out it there will be little bias ENSO wise toward a wet winter from the warm side of the sign.
Of note there is still a moderate Kelvin Wave headed east that has yet to really surface….so we still have hope…..
As far as winter predictions…..the Old Farmers Almanac is out….Which in my opinion is pretty worthless to me. It is calling for below normal snowfall for the Sierra.
So get ready for a very snowy winter? 😉
I think that the CFS system will have a better handle on things as we get well into October. After all….If we are really going to have an ENSO that will support more of a bias to wet for California, it will show up by mid to late October. And if there is no bias from ENSO, other teleconnection’s would have to be relied upon. I will have more on the latest teleconnection data later this week…..like the strength of the PDO and QBO…….
Update On ENSO:
The Dweebs had a look at the latest Kelvin Wave link for the latest subsurface SST information. It looks “IMPRESSIVE” from the perspective of reenergizing the Nino Basin with heat this Fall. FYI, In the core of that current Kelvin Wave is a small +4C isotherm. That wave is now beginning to surface and in fact the NINO 4 and 3.4 region has warmed “close to” + .5C warmer then normal. It will warm further this fall…
The CFS shows the Nino 3.4 region warming to +1C by January/February. However, the Nino 1+2 and 3 are actually a bit cooler through that period, giving way to a possible Modoki Event. Although this is encouraging for Southern CA, the Dweebs would be concerned for the inland areas of Central CA, if a true modoki event developed like in 1976-77….. as there could be significant split flow action if the subtropical jet was well south of Southern CA. Of course this is all chatter…..However, it would be much easier to forecast a wet winter for CA if all of the Nino Basin was +1.5C to +2C. for this Fall and Winter.
Dr Howard and the Dweebs……………………………….:-)
Temperatures over the Eastern Sierra definetly showing signs of becoming more variable as Polar Jet begins to flex its muscle over the higher Latts…..Fall like weather not that far off…..
Friday August 22, 2014
Posted at 7:47 am by Howard
A Northern Great Basin slider will bring the first shot of synoptic scale cooling to the Eastern Sierra as the stable weather pattern of July and early August gives way to a strengthening Polar Jet in the more Northern Latts…..Fall like weather has set in over many areas north of 60 N. The weather over the eastern sierra the next 5 days will be highlighted by periods of warming and cooling. The timing of the 1st shot of cooling will be associated with the slider later today and tonight where winds will precede the cooling this afternoon and tonight. Highs Friday and Saturday in Mammoth will cool to the upper 60s and low 70’s. Nighttime lows will drop to the 30s Saturday and Sunday AM. The further outlook shows the Trof progressing east Monday and in it wake, a subtropical high will build back into the high country rapidly Tuesday with an equally rapid warm-up Tuesday through Thursday. By Thursday, high temps will rise well into upper 70s. There is no rain in the outlook for Mammoth through this Thursday.
Labor Day Weekend:
Although tropical storms will track NW far off the Baja Coast over the warmer than normal SSTS, our weather should remain dry through the Labor Day holiday. Temperatures will continue to remain cooler than normal through this Monday then warm rapidly Tuesday through Thursday. The latest guidance shows TS activity actually aiding the warm up this mid-week as the release of latent heat from it’s precipitation process helps to build the subtropical ridge north-westward through CA. This will have the effect of returning daytimes highs over Mammoth to the upper 70s by Thursday the 28th.
Both ECMWF and GFS Ensembles favor a similar TS track and upper level wind flows that are not conducive for the advection of “mid level” subtropical moisture into Central California through at least Friday…. After which both global models differ with the strength of the subtropical ridge over CA. The GFS actually try’s to break down the upper ridge Saturday into Sunday. While the ECMWF hangs on to it longer. With that said, there may be plenty of high clouds Sunday and Monday (Labor Day) from both TS remnants/weak dynamics. especially over Northern CA if the GFS is correct.
In the longest outlook……….The CFS shows the possibility of a wet fetch of subtropical moisture between the 5th of September and the 12th of September into Central CA. More on that at month’s end……
Have a great week and a fun-filled Labor Day holiday weekend……..
Dr. Howard and the Dweebs……………………………:-)
Will discuss the Labor Day holiday weekend outlook Sunday….
Upper Level Low of the Southern CA Coast to get the Boot Thursday as Larger Synoptic Scale Trof moves though the Pacific NW….Warmer Early Next Week….
Wednesday August 20, 2014
Posted at 8:50 am by Howard
An area of showers and thunderstorms developed yesterday afternoon and lasted into the evening hours over Mono County. Although Mammoth just picked up a few light showers, accumulating precipitation occurred to the NNW of Mammoth. Todays air mass shows a slight increase in Precipitable Water. However as the day goes by, the divergence/convergence couplets now in place will probably weaken. There is still a slight chance of TSRW’s this afternoon into the evening for Mono County.
The Upper Low currently off the coast of Santa Catalina Island will get the boot into AZ late Thursday as a larger synoptic scale trof moves through the pacific NW. This trof will bring a little cooling Friday into Saturday with wind the main feature Friday afternoon into the night. This appears to be the first quasi insider slider type system to bring wind and cooling associated with a 110knot upper NW jet that cuts through Northern CA and NW Nevada. I am sure that it will be one of many as we go into the cooler half of the year.
Winds will crank up Friday afternoon into the night with gusts 20 to 40 mph in Mammoth and over 50+mph over the Mammoth Crest Friday night. It will feel like Fall Friday PM into the night.
Pressures aloft begin to build from the SE early next week partially aided by the tropical storm moving NW up the coast of Baja next week. With higher heights over the state, warmer temps will follow early next week and into the last week of August. Although the models all deflect most of the TS moisture WNW of Central CA, it will have to be watched as we head into the Labor Day holiday weekend….. Remember, models are guidance…….Not a forecast…..
Dr Howard and the Dweebs…………………………………….:-)