Archive for December, 2013
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………………………..:-)
Upper Ridge Parked Over California will Give Way to a Very Weak Coastel Slider…..Some extra wind over the Upper Elevations Friday Night and Slightly Cooler Temps Saturday……The Outlook is Still Dry Through Years End……
Thursday December 26, 2013
Posted at 9:29 am by Howard
It’s been fun to watch the week two progs of the ECMWF, GEM and GFS. After looking at them for the past few days, they all have the pattern transiting toward retrogression. The key will be where the upper high closes off. I do not believe that we can tell at this point or even possibly by the end of the new week where that will eventually be. However, teleconnection wise, if the Upper high ends up over Eastern Siberia, we’ll stay with fairly high heights along the west coast and mostly storm free. The ECMWF and GEM show that. However there is hope that it will close off further east over western Alaska. That teleconnects more favorably with a southern branch of the westerly’s reaching the central west coast. As mentioned in my past discussion we will not have a good idea where that will be for about another week. There will need to be a lot of water under the bridge flow though between now and then.
Keep good thoughts and the Dweebs will report on a regular bases……
Friday Afternoon Update: (Long Range chatter)
The CFS has been suggesting a change to the possibility of some precipitation beginning between the 8th and the 15th of January. There after on and off through the month of January. It gives something like 2 to 4 inches of water for the month for our area. Not a big deal for January but anything now is a big deal right?
Remember, this is the CFS, it is not really a weather forecasting tool. It is used more as a general interseasonal outlook. It is based upon Forecast Anomalies from Model Climatology. Now coming off a pattern like this, it is more of an outlook for Hope and Change. I know you all know about that….right?
The fantasy charts at 500MB during week two have for the past few days begun to show a change during the end of that timeframe. I see it in the GFS deterministic and the ECMWF control runs. Today’s 8 to 14 outlook for the CPC indicates that retrogression is going to take place week 2. I’ll take their word for it. At the least it means an end to the persistent ridge over head. When you get retrogression, you usually get amplification upstream and with amplification you can get undercutting of the jet stream underneath…..especially with January’s strong upper jet. However, the Dweebs have always said that we can go from one dry pattern to the next. Or we can get a storm in here, in-between. So what kind of change it is going to be no one knows for sure at this time. I will say that it is a good sign that the global models are following in step with the CFS thus supporting whatever the CFS has been touting….a pattern change week 2. Todays 18Z GFS had it as an “AR” (Pineapple Express) Pretty funny Huh….
What I can tell you is that you are all going to hear a lot of positive rumors out there over the next 7 days about a developing wet pattern. Be careful in buying into this one. I am going to tell you to keep your heart on this change, until what ever it is gets into the 5 to 7 day period. That’s because you just don’t go through a pattern like this and all of a sudden it starts dumping like it’s never going to quit. We are going to start seeing a lot of different scenarios in the global models and the spread in the ensembles is likely to get pretty out of hand before too long. However, in time the spread will come together and that will be the time to set the hook! What ever develops from this transition, we likely not know what it is for another week.
Stay tuned…….and be thankful for the great snow making system on Mammoth Mountain……
Dr Howard and the Dweebs……………………:-)
Upper ridge will hold into first week of the new year insuring warmer than normal weather for California and a persistence of dry weather. In the meantime a small feature will slide down the coast off shore. It is moisture starved and will only kick up some upper elevation breeze and some high cloudiness Friday into Saturday AM. No measurable precipitation is expected.
Expect high temps (8000 feet) in the low 50s except Saturday when it may be a few degrees cooler…
In the longest range of guidance, the ECMWF does try To break the dry spell toward mid month. However the GFS is still dry with no end in sight to the current pattern. As a side note it is noteworthy that although the (AO) Arctic oscillation is becoming more negative, there is still no change in California Weather forecasted. (None linear connection)
Let hope for the best and think positive in the European model. At least it is trying to give us some snow toward mid January. As of note, this is the driest start to the snow season since December 1999.
The latest ECMWF run now has (Tri) positive 500mb height anomalies built over 3 long wave trofs…. hemispherically. The Ridges are connectable from the Alaskan ridge to the North Atlantic, the North Atlantic to the northern Asia ridge and over the pole to Alaska. This essentially traps troughs in the far east, over the eastern US and central and western Europe. At the sometime, it traps the west coast ridge as well. This is a very stable pattern and one very difficult to dislodge, especially in January.