Changes are beginning to occur in the long wave pattern now with first of several North-South Slider’s over CA and Great Basin beginning Monday…..This is a colder pattern with Light Precipitation Possibilities in our future…

Friday 11:00AM:

No surprise’s this morning…  Models are consistent with dry cold front Saturday highlighted by wind and cooling. The following “Inside slider’ will dig back over the Sierra Monday and spin up off shore. Snow showers with light accumulations are expected Monday into Tuesday with 2 to as much as 6 inches possible over the crest.

Prind. point here is that the Eastern Pacific Ridge is retrograding by some 1000 miles to the west. This adjustment may continue slightly over the next few weeks or may adjust a bit back. Last nights EURO’s 5 days means are projecting a bit more westward movement, enough to drop a closed low down the coast sometime during the 3rd week of February. It’s ensemble’s retrograde the ridge to 150west or another 10 degrees west of where it will be by Sunday. The Ensemble Control is even more encouraging in that its 5 day means retrogrades the upper ridge to about 155 west by the period between the 18th and the 23rd. That is far enough west to set up a partial latitude trof off the central west coast for over water trajectory.

Now before you get too excited, this is the Ensemble Control and not the ensemble itself.  I guess you could gather from all this that “Things are moving in the right direction!”  😉

 

Dr Howard and the Dweebs……………………..:-)

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If you were in Mammoth today driving around town this afternoon and your car thermometer read 60 or 61 degrees, that was no error. It looks like we have one more day of that before our ridge begins to retrograde westward and chilly air moves south over the far west instead of all of it spilling east of the divide.

Although I still do not see as of yet as storm track from the West, there are some changes now occurring in the long wave pattern that are encouraging at the least. Looking at several global models the past few days there is a trend now of retrogression in the long wave ridge that has been mostly east of 130 W for most of the winter to shift westward to 140W.  This is always a location that will allow systems bringing chilly air from BC, Canada to drop south via the Pacific NW into either California or the Great Basin, depending upon the amplitude of the up-stream ridge.

In looking at the guidance yesterday from the European models Day+11, The Eastern Pacific Ridge is located along 140W. So expect a series of short waves to come south the next 10 days beginning this Saturday, bringing shots of Cooling and wind over the crest, and even the chance of some light snowfall. Another twist in the nature of this pattern is that these little short waves of energy can back up over the Sierra to the west coast, and spin up over water.  Depending upon the location of the spin up, there is always the possibility for one of them to draw in some subtropical moisture and then give us a very nice surprise!  I like surprises like the one that “may occur” early next week from a Cut Off low that may develop just west of between Paso Robles and Monterrey Bay. The Dweebs will keep a wary eye on that little bugger. Should it develop further south, it would mainly favor the Owens Valley and Southern Sierra, south to parts of Southern CA. These cut offs can be both unpredictable and unstable at times. They can produce some moderate to even strong convective thunderstorms on the west side of the Sierra and especially coastal communities with a lesser chance of some of them making it through into the Sierra. At this time, the models do not want to move this system once over water,  back inland anytime soon.  So well wait and see….

 

 

Mid Winter Blues to Continue this Week with Above Normal Temperatues and Light Winds….Slider Type System the end of the week may bring some Cooling and Breeze to the upper elevations….The Dry Stretch is likely to continue though Mid Month….

Wednesday AM:

This is just a quick update on some of the models and the handling of the Sunday night/Monday system. This morning, the GFS has come into line with yesterday mornings Canadian in taking the short wave west more over CA Monday AM.  However, The new Canadian is now further East. Obviously more time is needs for the Models to sync. BTW…the ECMWF is somewhere in-between….

This means that there will be at least some cooling, sierra crest winds will increase and there will be a slight chance of snow showers. Should the GFS this AM verify, there may be a few inches of snow Monday. as well as highs in the 30s

 

The Dweeber…..

 

Tuesday AM:

The is a slight change in the pattern coming as stronger short waves come out of the North Pacific and dive SE over the Pacific Northwest, Northern Great Basin and Rockies, the next 7  to 10 days. Although this pattern continues the trend of dryer than normal conditions for the Eastern Sierra, at least there will be periods of cooling and upper elevation wind. This will begin later this weekend and into next week. Both ECMWF, GFS and Canadian show a couple of chilly waves coming SE through in the Great Basin beginning the end of this weekend into next week. They handle the waves a little differently and so this will have to be watched over the next few days.  Odds are best that this will only bring wind to the upper elevations and cooling.  It is the 2nd wave that is of interest this morning. The EC and GFS take this wave over the Northern Great Basin and Rockies, so far enough east that they are moisture starved.  However, the new 12Z Canadian model this morning is spinning the wave up over the Pacific Northwest Sunday night and dropping it south over California Monday. It shows the upper ridge off shore sharpening up and backing to near 140 west.  This would be a cold showery pattern for Monday.  I think that for the time being, the forecast should stay dry for CA as there is the most consistency in both the GFS and EC.  However, at the same time, keeping an eye on those two models to see if there are any changes in the handling of that wave over the next two days.

 

Longer Range:

Per CPC discussion, although the MJO will be going into the colder phases for the Eastern US, the feeling was that there will be enough westerly flow across Canada to keep most of Arctic Air well to the north. However, it still maintains the Far Eastern Pacific Ridge, East Central Trof-Pattern across the CONUS. Looking at the Day Plus 11 means, the upper west coast ridge does retrograde a bit to about 140 west. This should be enough to allow periodic shots of energy over the Great Basin allowing cooler weather at times the following week. If the Ridge retrogrades to 140west, this would be a colder pattern for our area.

This is in itself is still a dry pattern. ( you can get light snow in a dry pattern)  If the MJO continues its march eastward from phase 8 to 1 to 2 then 3 and remains coherent,  it is conceivable that by week 4  (End of February and early March) snows will move back into the Sierra, based upon the MJO alone.

Last but not least, it appears that there will be a subtropical jet that develops over the Subtropical Eastern Pacific that may effect Southern CA…..Later this month.

Dr Howard and the Dweebs…………………:-)

 

 

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Monday 2/5/18 3:00pm

 

FYI Global models are trying brings us a cold inside slider type system around the 12th;  Possibly a little before or a little after.  ECMWF has the most over water trajectory. I only mention this as it is interesting to see that both the GFS and ECMWF are showing it to some degree.  This is a pretty cold system and would be good for some light snow showers at the least, if it comes though at all.   Stay Tuned…..

 

ECMWF EPS just started to Run…Will be interesting to see what it shows….

 

 

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A negative tilt, upper ridge will remain parked off the west coast with dry weather and unseasonably warm temperatures continuing for the Eastern Sierra. Light breezes, night-time temperature inversions will keep over night lows in the teens along the highway 395 corridor and lows between 25 and 30 in the Town of Mammoth. The only change expected in the pattern in the medium range,  will be a small slider type system over the weekend. This may increase breezes over the ridges and bring between 5 and 10 degrees of cooling by weeks end. The system will be moisture starved as its track is over land and not over the water.  Although there are some variable solutions in the week 2 progs of the ECMWF and GFS, the vast majority of their ensembles continue the trend of dry weather through mid month.  It is only during the second half of February that a meaningful change is expected in the pattern, the details of which are unclear.

For those wondering how the winter is faring water wise up on Mammoth Pass. DWP came in with their manual measurements a few days ago which determined that Mammoth Pass has 14.1 inches of water and is 51% of normal for February 1 and 33% of Normal for April 1st. The Town of Mammoth has 1.1 inches of water which is 8% of normal to date and 5% of normal for April 1st. (Huge Difference!)

When you check with the CA Department of Water Resources, you find that for the Central Sierra from Huntington Lake North to Calaveras’ Big Trees, that as of today, is in a dead heat with the Winter of 2014/2015 which was one of the driest years. However, that winter turned wetter that year during the first week of February where a storm brought between 2 to 3 inches of water between this week and next.  So more than likely we will be behind the winter of 2015 this week.  That puts the Central Sierra in a class between the Winter of 1977 and 2015. By the end of February, with a dry spell like this one, even with a wet March, it becomes increasingly difficult to have a meaningfully good water year….

 

Dr Howard and the Dweebs…………………:-)

Central California will continue with its Dry Winter and Punxsutawney Phil has no business forecasting the rest of Winter for California…

Mid Winter Blues continue for the Eastern Sierra

Friday the 2nd….

Well folks it Mid-winter!  February 2nd just happens to be the day that’s in between The Winter Solstice and the Vernal Equinox.  I will say that Mammoth Mt has done a phenomenal job keeping the fun in the sport by moving snow around, making it where needed, and overall, creating the best skiing and boarding experience in California today!

Weather-wise, it is pretty amazing how quickly the State of CA went from Drought to Deluge last Spring,  and now back to drought officially in areas of Southern CA. However, many reservoirs are still fuller now then they were over the past 3 to 5 years and that is due to good water management and of course last years amazing winter! As we all know now, no one has the ability to forecast a winter of the like’s of last year or this year.  Even the most pessimistic forecasts gave us only 67% of normal this Winter. We are nowhere near that today. Statistically, according to Jan Null Meteorologist and CCM for Golden Gate Weather,  there has never been a winter or rainy season that has come back to normal levels from a deficit like this for the Central Sierra.  Will this be the year that breaks that statistic? SEE:  http://ggweather.posthaven.com

OPINE;

The Climatic Prediction Center’s last update says that our current La Nina signal “ENSO” will become neutral this Summer.  However, NCEP’s Climate Forecast System is currently indicating that La Nina will last through the Summer and into the Fall.  We’ll see what happens after the Spring barrier that often makes that difficult to forecast.  Remember that last Spring, NCEP was expecting a major El Nino! We ended up with a weak La Nina. Later this year I will be focusing on the QBO teleconnection. It will become positive at some point and that is a good situation if everything else stays pretty much the same.  With the expected ENSO neutral conditions and a positive phase QBO, we might we go from Drought to Deluge again in 2019 with “ARs”.

 

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OK the Eclipse is over, this is the first day of February and tomorrow is Groundhogs Day!

Let talk about Groundhogs day.  The saying goes that if Punxsutawney Phil in Punxsutawney PA sees his shadow at about 7:20AM EST there will be 6 more weeks of Winter. I say Hogwash!  Why? Although there may be some relevance to the weather in the east, the weather pattern in the west is usually the opposite!  Why?  It’s all about the wavelength. A deep trough in the east extending from say Hudson Bay, Canada sets up a ridge over the far west.  Its the pattern we have been struggling with for the past two months.   Here is another way to look at it.  If you see/hear of a forecast of a very cold winter in the east, odds are good that you can expect a winter of below normal precip in CA and warmer than normal temperatures.

Checking the latest model runs tonight, the only change I see is some sign of some slight retrogression in the upper ridge early next week that may bring both breeze and some cooling but no precip. This is followed by another slightly stronger inside slider that may bring additional cooling the following Friday. The MJO charts (RMM) show the MJO moving into phase 7 which will strengthen the ridge further and bring more warming this weekend and dump arctic air over the Great Lakes.  Next weeks cooling is questionable as the ensembles members are much closer to the coast with the upper ridge or over the state next week. Not a good situation.   If you want to see what the RMM phase space looks like;

See:  http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmm.shtml

In addition, a high pressure system over Alaska will develop and help direct Arctic air southward into the East via Canada.  This is called the negative phase of the EPO. (Eastern pacific Oscillation) SEE: https://www.esrl.noaa.gov/psd/forecasts/reforecast2/teleconn/epo.html

And finally, the Arctic Oscillation (AO) is also in its negative phase.  (High Pressure over the Arctic)  this forces more meridional flow and supports the Ridge/Trof pattern west to east even to a greater degree.  This is truly the Perfect Storm so to speak for dryness for the State of CA

See the AO teleconnection forecast:   http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.shtml

This all adds up to a very dry outlook. In order for things to change, the MJO would need to either weaken substantially or progress to the Dateline then Hawaii and remain strong. The models are not showing that yet and odds are they wont because of the weak to moderate La Nina Base state.   I still believe that as we going into the last week of February, more positive changes will occur as well as into March as the seasonal change takes place. These proposed changes are a result of the Sun climbing higher in the sky.