Archive for January, 2013

Pretty big Arctic system dropping out of Alberta, Canada this morning. Strong North/South 130kt upper jet along the NV/UT border.  Eastern Nv through the Rockies could get some platinum powder today….  Just NE winds over the Crest for Mammoth today. Clouds may kick off a few flurries as well.  Not much else going on for Eastern Ca other than a gradual warm up. Temps will invert again, going into the weekend. Highs in the 40s at 8K and lows moderating into the twenties.

The weekend storm brought about a foot total to the main lodge. Mammoth Mountain continues to have a base in the 10 to 16 foot range. The atmosphere remains in an “El Nino Mode” with High AAM and the MJO in Phase 7. The good news this morning is that tropical convection has finally started to shift east now…..As it moves east, there may be a period of wet precipitation developing on the west coast next week. The NCEP Global Ensemble Forecast System for the MJO shows it into Phase 8 by the weekend and strengthening.  The Dweebs belive that the global models may begin to show some interesting pattern changes in the next few days slated for next week.

These would tend to be wet storms for the coastal regions that would tend to weaken inland.

Here is the most recent post from the CPC:

For next week:

As we move into Week-2, MJO associated enhanced convection is favored to continue across parts of the south Pacific and Brazil and develop over areas of central Africa, southeast Africa and extending northeast to the western Indian Ocean. Moderate confidence is indicated for the eastern portions of these areas due to timing issues as the impact of the MJO would enter this area late in Week-2. It is highlighted here because often KW (Kelvin Wave) activity can precede the main MJO convective envelope. Drier-than-average conditions are forecast to shift eastward with the MJO and impact the Maritime continent and far western Pacific.

Weeks 3 and 4:

The MJO will continue to impact the extratropics in the coming weeks. MJO associated convection has shifted the longwave pattern eastward across the Pacific-North America sector and on average a “positive PNA” is favored with a ridge across western North America and a trough across eastern North America. Below-normal temperatures on average are favored across parts of the central and eastern U.S. into the first half of February. If the MJO remains robust through
mid-February and enhanced convection once again enters the Indian Ocean, chances may become elevated for above (below) normal temperatures
across the eastern (western) U.S. in late February. This is generally consistent with the latest CFS forecast guidance. In the mean, the MJO would also support drier-than-average conditions over much of the western CONUS, although the MJO would favor an *”enhanced subtropical jet” later in January into early February during the time when the RMM index is located in phases 8 and 1.

*Possible impact WX west coast

Note: Since this post, the MJO has been slower to begin its move east. As a result, the enhanced subtropical jet referred to may occur a little later in February…IE next week.  See: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncpe.shtml

Dr Howard and the Dweebs………………………:-)

Saturday AM:

MJO still stuck in Phase 7.

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Ridge in the west….trof in the east, MJO is in phase 7.  It all adds up to a drier then normal pattern for our area…with lots of splits in the short wave action and cut off lows for the west coast.  Typically this is not a pattern that will bring moderate to heavy snowfall and major storminess for the high country. However….Southern California benefits with the cut off lows tap subtropical moisture from the Subtropics and advect it NEward into their area.

The MJO has been stuck in phase 7. (Central Pacific near the dateline) It has spun up some major tropical storms in the southern hemisphere, one near Tahiti that is dissipating now.

The MJO in Phase 7 tends to force a ridge over the west (+PNA) and keeps the long wave trof in the east. The results are pretty much understood now with split flow patterns and cut off lows and subtropical moisture as storms try to come through the long wave ridge position over the far west. It does not work well.

It’s kinda like Forest and his box of chocolates. You never know what your gonna get, and often times where your going to get it. The models do not get it right very often in the current pattern and the longer range forecasts are often times much worse or worthless.

The MJO is expected to eventually shift east:

Looking at the GWO, Global Wind Oscillation:

It is quite strong and has moved past phase 5, (indicating strong mountain torque in the mid latitudes) and approaching phase 6 (southward momentum transport across 35 north.) AAM has become quite positive (El Nino Like)  Still no sign of any extension of the eastern Asian jet, however that would not be expected until the transition into phase 8 if it occurs at all.

So whether we get under cutting or not, at some point the MJO will move to Phase 1 again and reemerge out over the Indian Ocean. That should flip the ridge trof pattern over the CONUS and return the west back into a cold wet period….sometime later in February….possibly much later…..

In the meantime, it is important to know that Mammoth Mtn picked up 7 inches of fresh snow Wednesday and Thursday. We’ll probably pick up a few more inches and hopeful a little more over the weekend. Snow Levels will remain between 8500 and 7500 feet until Saturday night when the snow levels really come down,  with the cold air advection Sunday into Monday.  Mondays highs will be in the 20s while the lows will be in the single digits. The Dweebs expect milder weather returning by mid week.  No Major storms on the horizon at this time…..

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