Retrogression in process with first in series of systems initiating a strong Mono Wind Event for Tuesday…..Much cooler weather on the way!

After several days of beautiful weather, big changes are coming to our weather pattern. Currently, as expected, retrogression of the Eastern Pacific High is in progress.  The first system will be headed in Monday AM with some snow showers and another one fast on its heals for late Monday night into Tuesday night.  The Tuesday system will bring very strong ENE winds to the sierra crest. An upper low will form rapidly over Nevada and move over the sierra crest  Northeast to  Southwest.  Gusts in the 150 to 160 range not out of the question as the jet touches down. This is a very similar scenario when a “Mono Wind Event” blew down thousands of trees just west of the sierra crest, from west of Mammoth Mt north to Tioga Pass.  This event may reach further north… Its important to note that damaging winds do not occur in the Town of Mammoth from this pattern as well as many lower elevation areas east of the crest.

Beyond the Mono Wind event, the whole idea of retrogression is that each successive storm drops south, further west with time, so that they will eventually have over water trajectory. Over water trajectory that benefits the central sierra is expected as early as the next Friday, with another one that develops further west the following Monday and another later during that last week of January. This pattern is not suggesting any “AR” type scenarios as the short waves travel mainly North to south with little fetch.

Our weather that has been very warm for this time of the year is going to get cold with highs lowering into the 30s. That’s a 20 to 30 degree drop. It appears that the cold weather will be here to stay, for at least a week once it sets in.


More Later……


Dr Howard and the Dweebs…………………….:-)

Strong Ridging Develops the next two days with very mild temperatures for the high country…..Highly Amped ridge will begin to slowly retrograde early next week with cooling….Weather to remain dry through the 21st with a major change in the pattern taking place over the following weekend….

Our Weather in Mammoth is way too nice for the middle of January!  The Dweebs were in short sleeve shirts today as highs approached 60 degrees in Town.  Lows at night are now above freezing….. It will be warmer the next few days as the current ridge Trof pattern peaks out.  Remarkably,  It is quite unusual that our high temperatures in Mammoth are about the same as Reno, NV. However, that is testament to strong ridging in January with strong temperatures inversions as well.

Our Ridge Pattern peaks out Friday, with highs in the low to mid 60s!  Next week should cool down a bit.   As the eastern pacific ridge begins to slowly back up, cooler air will begin to spill southward through the Great Basin., Monday and Tuesday, High temperatures will be back down into the 40s next week with nights seasonally in the teens.

Pattern in Transition:

I just had a look at the 12Z ECMWF Ensemble, 5 day means.   Its a good guide in telling you where the pattern is going and how it will effect a particular area, weather wise.  The Eastern Pacific Ridge is currently between 130 and 125west. Over the next 24 to 48 hours, its positive tilt and height anomaly will give our state an exceptionally beautiful few days with near record highs Thursday and especially Friday.   Looking at next weeks weather, the ridge in the 5 day means continues to retrograde westward. Its expected that it shifts west about 1000 miles from its current position by next Friday the 22nd. The long wave Trof backs west as well to the Rockies. This initiates the very beginning of a storm track with NW sliders and a possible unsettled period that following weekend. Temperatures will be much cooler. As we go through that 4th week and final days of January, the eastern pacific ridge, as progged by the ECMWF, retrogrades west to 165 west.  If that is the case, there will be a lot of storminess between the following weekend and the end of the month.


Dr Howard and the Dweebs………………:-)








Flat Dirty Ridge to become highly amplified next week as Polar Vortex desends southward……Our Long Range Dry Outlook is not set in stone!!

The Strato Warming is in process.   Temperatures have risen strongly over the stratosphere above the arctic,  increasing high pressure below in the troposphere. It will be interesting to see what the long range models will do with the Polar Vortex’s over the coming weeks. Over the western hemisiphier, the global models at 500MB show the PV strongly developing near the Hudson Bay Area by mid January. This really amplifies the planetary wave pattern with Trof-Ridge Trof pattern between the dateline and the Eastern US.   This highly Amped ridge is whats in store for the far west next week with very warm temps for California, especially the southern half, Wednesday through Friday and possibly Saturday. After that, all hell may break loose over the northern hemisiphier the following week….

At the moment, the Polar Vortex has been broken into a few parts as the displacing polar positive height anomaly develops. Week (2) of todays 12z Euro shows several more PVs breaking off forming smaller ones all over the northern mid latitudes.  Currently, The major PV is deep over far Eastern Asia with a smaller one over Western Europe. The Sudden Strato warming has really done its job, with 500MB heights anomaliously high over much of the Polar Region. The stage is set for some really “wild weather”, during the latter part of January. However, no one really knows how it will affect the west coast yet. Again, next week, the Euro has the PV setting up near the Hudson Bay area with a highly amped ridge off the west coast. (Cold east/warm west) Over-time, there looks to be retrogression in the positive height anomaly and that’s where our pattern can really change.   I would NOT! put much faith in the week two models yet, untill we see how this change affects the northern hemisiphieric pattern as our west coast weather evolves.

PS plan your bike rides Wednesday through Friday….:-)


The Dweeber……………….:-)