Archive for January, 2013

Another Wave of Cold to hit the Sierra Thursday with well below normal temperatures….Some Light Snowfall expected Thursday with Friday the Coldest Day….The Cold will remain into the Weekend with milder weather returning by the middle of next week at Resort Levels…..

A well amped upper ridge will build northward along 140W tapping some Western Canadian Air which then plummets south down the west coast. This will bring the return to frigid conditions by Thursday night that will remain through the Weekend. Light snowfall will develop late Wednesday night toward Midnight and continue into Thursday. At the moment, only a few inches are expected through Thursday night, so a nice freshening of the deep snow pack in the Sierra is expected.

So far the forecast models are pretty dry with this next system. However, my experience has shown that storms like these can often times fool forecasters.

The upper level winds moving up and over the Sierra will be natural to the Sierra for a time.  So there will be a period of orographics with the height falls. There will also be a period of over water trajectory creating more of an “ocean lake effect”. So the up shot is…..Do not be surprised if we get a bit more than forecasted.

Beyond the upcoming short wave for Thursday, there will be an inside slider bringing mainly light snow showers and a little up-slope Saturday night. Possibly some Mono Lake effect?  Over all it will get very cold again and the cold will last through the weeks end. However, it does not look as cold as it did for this upcoming weekend as it did 4 days ago as the upper ridge does not build as far north and is a bit further east..

The weather next week will be highlighted by the off shore ridge progressing into the state of California. This will cap over any remain cold air in the valleys and bring quite a warm up to the resort levels. We may experience 50 degrees at the 8000 foot level in Mammoth by Wednesday/Thursday and possibly beyond into the following weekend.

OUTLOOK:

A strong MJO is currently building in Phase IV and is forecasted to move through Phase V and eventually Phase VI. In this sequence, a ridge is often found in the East and a trough in the West. Eventually a flip in the pattern is likely by the middle of next week with a ridge near the west coast and a deep trof in the east toward the end of next week.  Later in the month of January if the MJO remains strong and progresses, we may see an extension of the East Asian Jet occurring across the pacific. This may be associated with undercutting or a split in the jet with a southern branch headed for the Southern half of California about the end of the 3rd week of January. This may bring beneficial rains to Southern California.

 

Dr Howard and the Dweebs…………………………………………:-)

 

Upper Low Located Just southeast of Monterrey….To shift slowly ESE this AM….Then Slowly SE tonight…Snowfall to increase Later this morning for the Crest and Resort Levels…

10:00AM update:

Although the track of the upper low was forecasted to move ESE. The actual track is right down the coast so far. So it appears now that the crest will not benefit from any significant UVM.  Upslope is already beginning to show up on the wave loop and so will back down snowfall amounts for today to the 3 to 5 inch range along the Eastern Slopes of the sierra.  There will be an increase of NNE wind Monday AM, confined mainly to the crest.  We will ridge up Tuesday into Wednesday for some fine weather with milder temps!  Next colder system to bring light snowfall and breezier weather Thursday.

 

So far snowfall has been “mostly” confined to the north of the upper low, now located just some 50 miles ESE of Monterrey. This system will move very slowly ESE today then SE later tonight. However the system will not exit Ca until Monday mid morning. According to the new WRF,  it follows a path ESE to Bakersfield by 10:00am Sunday, then is located near Baker Ca west of Vegas by mid evening. It then drops SSE to the Parker Dam in AZ by Monday at 7:00am. This system never crosses the Sierra. However the circulation will favor the crest initially then wrap back around, and up the eastern slopes of the Southern Sierra as it shifts SE. This is a more difficult system to forecast snowfall. Not only amounts but timing as well.

So best guess at the moment is that the crest will still get the lions share as it usually does with 6 to 12 inches by Monday AM. The Town of Mammoth will get 5 to 7 inches, with 3 to 4 inches along the highway 395 corridor, especially along the southern half of Mono County. It may be that we get most of the precip in town from the back wash from this small system.

There does not look like any potential flight problems leaving Mammoth Monday. However, it might be a bit bumpy landing at LAX Monday PM as there is a 120knot upper jet that spins up on the upper lows back side Monday morning.  The San Gabriel’s Mts south to the adjacent valley may have a strong Santa Ana Monday AM as well.  We ridge up Tuesday into Wednesday with the next drier system effecting Mammoth Thursday.

The two most watched global models are going in different directions for next weekends short wave and pattern change. Now with a drier and not as cold scenario. However, for you cold hounds it will still be plenty cold!   Will up date over the next few days on that.

What the Dweebs are seeing is that the MJO is moderate now in phase 4. It is forecasted to translate into phase 5 next week then eventually phase 6. This effectively forces an extension of the Eastern Asian jet toward the west coast the end of week 2.  This may force the pattern over the CONUS to become progressive and eventually open the gates for wetter storms later this month. This is really a change in thinking…so will update as time permits….

 

Dr Howard and the Dweebs……………………….:-)

 

 

Cold weather to continue for the far west with next spliting system bringing light amounts of up to 6 to 12 inches over the higher elevations Sunday/Night..Weather to turn even colder by Mid Month….

12:00pm Saturday Update:

New 12z ECMWF is in and looking at 240 hours out, dumps all the cold air into the great basin like last nights GFS.

Now take a look at the 6 to 10 day outlook for the Great Basin…..Burr!!!

As well as the analogs: http://www.cpc.ncep.noaa.gov/products/predictions/610day/610analog.off.gif

Analog Temps probabilities… http://www.cpc.ncep.noaa.gov/products/predictions/610day/610analog.temp.gif

Also the GFS AO forecasts suggest that the AO will tank to standard deviations of normal,  > -5 by Mid Month.

See http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.mrf.gif

If you remember the 27th of December 1990, it was cold!

As a comment,

The up shot to all this is light to moderate snow within the next week…..then cold and a lot more cold the end of next week.

We have a couple of snow producing storms headed our way. One Sunday and Sunday night that will dump about a foot on the hill.  6 to 8 inches at the village for a Sunday night plow.

Additionally, A better snow producer with more wind is expected Thursday which will be the first of several more but drier storms that will deliver Arctic air into the great basin, later the 2nd half of next next week.

Dr Howard and the Dweebs………………………….:-)

 

Saturday AM Update:

I keep seeing the same trend in the longer range this morning….Burrrrrrr!!!!!

RECAP:

1. It all began with the west warmer then normal in the Fall….then much wetter then normal in the late Fall.  Anomalous cold developed in December.  All this while the QBO was in its easterly phase with the 30 mb zonal wind index showing -20s in September and -20s in October then -18s in November and rapidly rising to -10 in December. The Quasi Biannual oscillation is represented by an index that shows both the strength of the winds at 30MB, (Stratosphere) from either east to west or west to east. It has been in its easterly phase now for well over a year and is expected to flip soon from from east to west to west to east.   From what I have read, the most dramatic effect upon the weather often time occurs during the time around the flip in direction. This is often associated with strong blocking over Greenland, IE a strong -NAO (a strong high pressure block over Greenland)  and a deep Hudson Bay Low. The combination of the timing of the flip which is beginning to occur now and will likely continue into February, and what the CPC is touting is leading me to believe that some serious Arctic air is going become entrenched over the CONUS later this month. It will mainly be from the Mid west then shift to the east!..For the folks that are missing the cold over the east, it appears that you are going to get yours big time, the second half of January. This Arctic Air may go deep into the south….. and the AGW crowd will be touting otherwise again!!

See: http://www.cpc.ncep.noaa.gov/products/people/sweaver/cfs_fcst/images1/wk3.wk4_20130104.NAsfcT.gif

Back out west……there is still the possibility that the first initial salvos of Arctic will begin in the far west with some of the thick soup breaking west of the Divide about mid month. The Cold will then shift east with time. If we do get a good shot of it and ridge over; as mentioned in a previous discussion, Bridgeport may go -25 to -30F.

Take a look at the following link. It is the latest forecast from the CPC for temps across the US.  The deviation from the standard is grossly off the chart!

 

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I took a trip to the Carson Valley, Nv via Bridgeport today. At 1:45pm it was 14 degrees downtown. That was probably about the high for the day after an early morning low of -18. A few days of that are tolerable I guess, but a week or more and I’d be ready for the head bangers ball! Lee Vining next to Mono Lake still socked in with ice fog at about 1:15pm today. I hope you folks get some relief this weekend as a splitting system tries to mix things up a bit. Some snow is expected for the High Country. However, mainly the Crest and south through the Southern Sierra. I would not be surprised if bishop picks up an inch or two of snow Sunday/ngt. Mammoth Mtn is expecting about 4 to 8 inches by Sunday night. Could be 3 to 6 inches in town.

 

What I have been seeing on and off for mid month January in the longer range concerns me. Especially since it has been so cold for so long in many areas. Not every model is showing this on a regular bases but the new 00z Saturday GFS has the eastern pacific ridge building north at about 145W to the north pole and tapping pure arctic and pulling it South over the far west and especially Great Basin. Temps over Montana at 18,000ft (500mb)  go south of -40C. This is just about our coldest weather type should it occur…..Especially in mid January. With so much snow cover over the interior far west and great basin, there will not likely be very much if any modification. Stay tuned…..as the mid month Yellow Knife clipper could be a real pipe buster!  If that occurs and we ridge up over the top of that air mass…Bridgeport could go -30f below.

Note this is not a forecast yet. However the trend is heading toward an Arctic Outbreak over the west by mid month or a little sooner. How far west the molasses gets is uncertain at this time.

 

PS>   The QBO is getting ready to flip from east to west to west to east. Looks like Next month will be the timing……

 

The Dweeber………………………:-)