Persistance in the Current WX pattern to Continue Through the End of this Week…………Some Changes in Store Next Week……………
Thursday January 2, 2014
Posted at 9:44 am by Howard
Sunday AM Update:
Fridged air mass invaded North Dakota this morning and will make its way to Western Wisconsin by 6:00pm Local time. The coldest portion of the air mass arrives well after the Packers game is over. This is a timing issue and a good thing for the players and fans…. Don’t get me wrong, it will be cold, but not nearly as cold as the 1967 game.
As the (PV) Polar vortex swings through the great lakes region and eventually redevelops east of Hudson Bay Tuesday morning, the trailing Upper Trof finally kicks its way out over the Atlantic Tuesday afternoon. As mentioned before, this creates an excessive wave length and allows the west coast ridge to:
2: Retrograde to 140west by mid week next week.
3. So the 1st system that comes through the ridge Tuesday washes out with just clouds for us. The Second system is an interior CA slider bringing wind, cooling, and some light snowfall Thursday.
The QPF is pretty light at the moment. About 1 to 3 inches in town. The crest might get 3 to 5 inches by Friday AM.. Maybe……..
Than that’s it for quite a while
No Change from the last discussion other than to mention that there will be a couple of small systems coming through the weakened west coast ridge next week that may bring some light snowfall to the Eastern Sierra. Like a comet that emerges after a trip around the sun….there is no telling from this distance in time, what will be left of the two systems once they emerge through the west coast ridge into California. In the meantime, it will be a little cooler Saturday night and Sunday due to some cooler air following an Ajax/Aspen, Co Slider. So a little increase in Sierra Crest wind is possible Saturday afternoon into Sunday AM. Upper ridge Rebuilds into Following weekend…..
PS….. Is little Nells still in Aspen? Use to work for the Aspen Ski Corp Winter of 1973, top of chair 6. Someone let me know…..
Taking a look at the new 12z Thursday GFS deterministic model, and last nights EC, there is a chance of a small storm sneaking in here about the 9th. Here is what the Dweebs are looking at. 1st of all I will preface this by saying that for sometime now the CFC has had something getting in here about the middle of January. I know that is the pretty amorphous, however, there are some changes down stream that may allow some energy upstream to get in here for some light snowfall later next week.
From what I can see, in the coming days….the big polar vortex over Canada that will put the big freeze to the northern mid west, and then eastward will be shifting out over the Atlantic early next week. The key here is that it opens up a big wave length between the vortex (PV) and the west coast ridge. Even through this ridge is still very much alive and well in the eastern pacific, it gets weakened. Weakened enough to allow some short wave action into the west coast between the 7th and 9th of January. The ECMWF has a few systems coming in from the northwest that would bring us some light snowfall. And yes, they may be inside sliders. However, they may not be as well. This mornings 12z deterministic GFS run actually splits the ridge with a short wave coming toward the central west coast Thursday then moving SE making landfall near San Diego. Because of the distance in time, there will be other solutions to this particular short wave…the wave of Thursday January 9th.
If this wave spins up and moves into Southern Ca, we may get some upslope/wrap around. However, the main message here is that this is the classic system that will affect parts of California in a drought pattern, giving coastal sections of Ca some light precip. If by some remote chance the system split out to sea further north….Central California would do better and we might get lucky with a foot. At this time…..It is too far out for any confident forecast to determine what track it will finally take.
What I like about the change in the pattern is that an excessive wave length is finally forecasted to occur next week. I like to give credit to some of my mentors when due…..So Tom C…thanks for the memories…….
2013 in California to End W/ Driest year on record for Several Areas…San Fransisco for one, Statistics Now….All the while there is no end in the Dry Spell at this time….
Tuesday December 31, 2013
Posted at 10:19 am by Howard
Apparently the upper ridge is doing nothing but shifting east and west between 140W and 120W and sometimes flattening. If the upper ridge remains in this mode, all we can expect is either a mild pattern in its east mode with warmer then normal temps for this time of the year. In its west mode, shots of cold air advections with either light snowfall or showers and wind. The ECMWF has been touting an westward shift in the upper ridge the 2nd week of January. That would lead to colder weather with windy conditions over the upper elevation’s along with some light snowfall during the 2nd week of January.
I have not heard what is causing the severe dry spell. However one thing I do believe is that it is not global warming. There are too many areas that are having severe cold hemispherically…..
Dr Howard and the Dweebs……………………….:-)
ECMWF is attempting to retrograde the long wave ridge west…..where it was in early December with very cold weather returning by the 2nd week of December. There will likely be some snowfall in this pattern but light amounts week 2. The GFS is not in agreement thus far. However, typically the EC is the better model on the west coast at this distance…..so stay tuned…………………………..:-)
The MJO is in Phase 6. It is expected to move to phases 7 and 8 the next few weeks. Tropical convection will move east toward the dateline and possibly beyond. Will keep an eye out for any funny stuff if you know what I mean…..
Dr Howard and the Dweebs…………………………..:-)
From Tuesday Night:
Happy New Year from the Dweebs………………………..With only about an hour left of 2013, here are some of the records for the driest year on record for Central California. Aren’t you lucky to be around for a once in a lift time experience?…………………….Not!
Thanks to Jan Null, CCIM, here are the records for many areas in California and SFO, which is due west of Mammoth Lakes. Compare to water years of past.
(Read and Weep!)
Although dry weather is expected through the 1st week of January……some cooling will occur in back of a storm headed for the Rockies Saturday……There will be lots of high level cloudiness over running the upper ridge off shore, throughout the week…..This current pattern in January is historically very stable with the westerly phase of the QBO and +AO. The AO has gone weakly negative recently and is expected to stay that way through the first week of January then go moderately negative second week of January. With the NAO in neutral mode, forecasts show that the PNA region which is an indicator index relevant to the location of the eastern pacific ridge will remain neutral the next week. Simply, the upper ridge will remain far enough west to allow some cooler air over the far west from time to time. Remember that in order for the PNA (Pacific North American Circulation Pattern) to be positive, 500mb positive height anomalies need to be centered over British Columbia rather than in the Gulf of AK area. On another note, if the PNA region was strongly positive now, we would most likely have above normal temps at and above 8000 feet both day and night for weeks! So thank goodness that is not the case today.
So what is there to look forward to in the weeks ahead? Not much…….
The quasi biannual oscillation (QBO) remains strongly from the west. Last November, the QBO actually strengthened as a comparison to Oct when we were head-faked into believing that the QBO was beginning to weaken toward neutral. According to Research, when this QBO begins to weaken, there is a significant increase in high latitude Northern Hemispheric blocking. Index: (Sept) 13.12 Oct (11.69) Nov 12.45; Dec??
In a few days, the index for December will be out and will be of interest to see if the QBO is in a weakening phase. Because it is an oscillation, it has a cycle and the timing is coming soon for the flip from positive to negative. For strong High latitude blocking an index of between +8 and -8 is best for the index.
For the index see: http://www.cpc.ncep.noaa.gov/data/indices/qbo.u30.index
Now high latitude blocking in the NAO region will not help California’s dry spell. In fact it may make it worse. However, it will have a profound effect upon the NAO and AO to negative. That in turn may disrupt the current pattern. (wishful thinking?)However, more likely, the north, central and parts of the eastern CONUS will turn very cold as meridianal flow develops. Odds are, when and if this happens the PNA region will become strongly positive and the Upper ridge may even become more orientated over California and not off shore. Mild (Dry).
Back to the MJO….. The forecast is for the MJO to strengthen in phase 6/7 week 2. SEE: (NCEP Global Bias-Corrected Ensemble Forecast System) See: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncpb.shtml And the EC; European Centre for Medium Range Weather Forecasts Ensemble System (EMON) See: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/emon.shtml
The MJO strengthening and moving through these phases is not going to break our dry pattern. We may get a small storm or two mid month in a transition but not what we need. However, AAM is on the increase with mother nature putting the peddle down which may cause amplification over the PNA region.
Furthermore, according to the CPC, 30th of December report, enhanced convection along and south of the equator in the western pacific, due in part to the MJO could contribute to long wave amplification across the PNA region during week 2 and beyond, enhancing the likelihood of cold air outbreaks across the Central US.
Comment: Cold Air out breaks over the Central US and amplification in the PNA Region is not what we want to see in the coming weeks!!!!!!! This still spells a Dry,Dry pattern for California.
If, and this is a big if…..the MJO stays strong and progresses into Phase spaces 8 then 1…….We could pineapple-up. However, at this time, that is just more “Hope and/For Change”
Dry through next Monday, highs mostly in the low 50s lows in the 20s. Breezy Friday and cooler Saturday (Highs in the 30s) A slight chance of a storm about the 8th-9th of January……The Dweebs will know more, later this week.
Clear Sailing through New Years Day…..then cooler possibly windy weather Friday into Saturday with a slight chance of showers Friday night and Saturday next week…….
Sunday December 29, 2013
Posted at 1:39 pm by Howard
Dry WX to continue this week with a chance of a pattern change next week. The GFS has been trying to break some energy underneath the big upper ridge. No guarantees though….ECMWF has a little snow for us (Few Inches) around the 8th-9th)
Otherwise it will probably be cooler and breezy next week as well. Remember…..in dry years…you can get a storm in here between dry patterns….
Both 12Z and 18Z GFS and ECMWF are very different in their extended runs as I indicated that they would be in the coming week. Their differences are even greater beyond the 7 to 10 days period. Sensibly, it is noted that our current upper ridge will weaken later this new week and give way to either a NW slider or an inside slider. The main differences will be mostly in the amount of wind we will get and the amount of cooling. For the most part, both models continue the dry weather pattern with no relief in sight next week. Expect a chance of showers Friday night/Saturday……That will be it.
The only optimistic part of the long range is in what we call fantasy land or week 2. It is good that the GFS is in disagreement with the EC and GEM. This is the period of time of most interest….. The fact that they are different is cause for the thought that something is going on that the dry models are not seeing. More over, all these models at the least have some of their ensemble members showing undercutting. The MJO although weak is moving through the phases. Currently in Phase 5/6. (AAM is on the increase)
Dr Howard and the Dweebs………………………..:-)