Archive for January, 2013

Complicated pattern for the High Country next 5 days….Periods of Light Snowfall expected over the Upper Elevations through Monday….Turning Colder again early next week…..

What happened to the models!!

Early yesterday AM confidence was increasing…now it has collapsed as they all going their own ways on handling the next 5 days.

Again…The forecast models have gone their own way in trying to handle the energy over the eastern pacific.  The upshot is the Euro model has gone a lot drier as compared to the last couple of days for QPF. However, they may now be actually under-done.

Looking at the the eastern pacific sat picts, there is a lot of subtropical moisture to the SSW of Mammoth that is left behind from a circulation center that has since dissipated. An approaching splitting short wave is drawing it NEward into the sierra. This moisture is going to move up and over the Sierra, later today and especially tonight and early Thursday.  The higher elevations mainly above 8000 is going to get some light snowfall, possibly some 2 to 4 inches at the village and between 4 and 6 inches at and above 9K. This will occur, mainly tonight and there may be an additional 2 inches up there Thursday. Then there is the portion of the split off circulation center that “may” lift NE and wrap some slight snowfall back up and around from NV into the Sierra Friday/Ngt. This is just a slight chance.

Then we have the kicker wave coming in late Saturday PM into Sunday followed by a cold inside slider early Monday morning.  What a &^%$#!  Mess!!

 

Stay Tuned!

 

The Dweeber………………………..:-)

 

Storm System for the Weekend looks to Dump Upwards to 2 feet on Old Woolly…..Then Snow Showery and Cold Monday for a Powder Day!

Confidence is now increasing between the GFS and the EC that the “slower more clustered ECMWF ensemble solution” will bring a good snow producing system to the Sierra over the weekend. In that now we have better agreement that the slower solution is preferred, upwards to two feet of snowfall is expected over Mammoth Mountain based upon last nights 00z Tuesday guidance. Additionally, between 6 to 12 inches is expected in town. The storm will begin very late Friday night with some very light snowfall that will continue into Saturday morning, with the tempo picking up Saturday afternoon into the night. By Sunday Am upward to a foot is expected on Mammoth Mountain and “about” 3 to 6 inches in town.

Additionally….The slow movement of the system will allow snowfall to continue well into Sunday. The upper flow will be natural to the Sierra and so good orographics combined with ample vertical motion is expected to produce upwards to another foot by Sunrise Monday morning. This 2nd part of the storm will be colder and so snowfall will be lighter. It may even fluff out to be higher amounts then a foot.

Monday looks partly cloudy and cold with possibly some light upslope snow shower action. A powder day for sure! The ECMWF’s QPF just west of the Summit has settled down to about 2 inches now which looks more reasonable. This mornings new HPC 7 day total precip bullseye’s the precip right over the top of Mammoth Mt. The storm has got some cold air in it, so although snow levels will begin higher….the freezing level should be down to about 5500ft by 10:00am Sunday, with snowfall effecting most of the Mono County Valley floor areas during the afternoon. Further cooling is expected throughout the night and into the early morning hours with the freezing level near 4000 ft by midnight Sunday night. Snow levels typically are 1,000 to 1500 feet below the freezing level.

In the meantime, there is a splitting system that will bring some very light snowfall Wednesday night. An inch or two is possible over the crest and up to an inch in town is certainly possible.

For the time being…..this weekend storm looks to be a one storm scenario before we ridge up again later next week. Looks like the Mono Lake freezing fog will be back for a time…..

More Later…………………………….>>>>  🙂

Mid Winter Dry Spell Will Gradually Come to an End This Week Bringing Relief to Those Living Below The Inversion…..MJO on the Move……>>

Sunday Evening Update:

Took a look at the Sunday 12Z ECMWF QPF for next Sunday night through Monday night over the Mammoth Crest. It dumps between 3 to 4 inches of water eq compared to the 18z GFS which dumps about 1/2 an inch the same time. Lets see…that the difference is about 5 inches of snow compared to about 3 feet.  Lots of time to work this one out….Update in the AM:

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Relief is finally in sight this week to those that live under the inversion trapped in the cold air. Mono City and Lee Vining residents living near the influence of the large body of water and open heat/moisture source has been effected more often than not the past month. The radiational cooling effects of the atmosphere and subfreezing air-mass trapped below sinking air, in combination with the thermal heat source from the lake radiating into it has kept Ice fog conditions at times, day and night.  Bridgeport whos high temps has ranged from the teens and 20s and lows from 0F to -29F will begin to recover by mid week, as temperature inversions begin to break. As this as a system to the north of Ca will weaken the 500mb upper level ridge over the far west Wednesday.

Comment: It looks like the lower elevation valleys have through Tuesday to deal with the fog and cold. By Wednesday morning, a system to the north should be strong enough to mix you out.

Here in the High country at the 8000 foot level, temperatures have been slightly above normal!  Highs have been in the 40s the past week with lows from 8F at the Mammoth Ranger Station to the upper teens and 20s at the Village at Mammoth in the Banana belt. Breezy weather will begin to develop over the Sierra crest out of the WSW later Tuesday night then into Wednesday. The upper level winds will eventually become North Westerly. We will ridge up again Later Thursday into Friday temporally.

High temperatures will remain in the 40s in Mammoth at 8000 ft through Tuesday with lows 10 to 20.

The Weekend:

Increasing clouds and winds with snow developing Saturday night into the following week. (1st week of February)

See: the Cut Off Low forming to our SSW. The Dweebs will have to keep an eye out for this Subtropical moisture source by weeks end

http://www.ssd.noaa.gov/goes/west/nepac/flash-ir2.html

Interseasonal:

Some Information about the AR:

“The Pineapple Connection is a popular term for a wide range of Atmospheric River connections with high Moisture Transport flows into California measured by Kilograms per microseconds within the actual flow. The historic range seems to be between 500 KG/m/s and 3500KG/m/s historically. The most intense single AR event occurring between 1948 and 1999 occurred with the event crossing at 35N in February of 1986. That was the Atmos-River that caused the famous avalanche slide that took the pines down Sherwin Bowl on the 19th of February. Over 10 inches of rain fell on top of a rich snow pack over night. It flooded the Truckie River to the north and made it impassable for roads crossing perpendicular between Nevada and Ca.”

See Also: http://www.esrl.noaa.gov/psd/atmrivers/

http://65.74.139.74/2005publications/CEC-500-2005-004/CEC-500-2005-004.PDF

The MJO that has been slowly moving east the past month that initially intensified the first week of Janaury has been Canonical in its impacts in the subtropics and the down stream effects upon the mid latitudes. Read the following discussion from the CPC which relates to the weather across the CONUS for the upcoming week and beyond:

 

From the CPC:

Week-2, confidence is fairly high that the MJO will continue through phase 7, possibly into phase 8.  Therefore, the outlook is based largely  on phase-7 and phase-8 MJO composites, adjusted slightly using model guidance. Enhanced odds for above-average convection is indicated across the far eastern Maritime Continent, centered near Papua New Guinea extending eastward well past the Date Line, generally along and south of  the Equator. Drier-than-average conditions are favored over much of the equatorial Indian Ocean and western Maritime Continent. The forecast MJO phase and model guidance are generally supportive of an enhanced risk of tropical cyclone formation in South Pacific. The forecast precipitation dipole over South America is continued from Week-1 with
high confidence due to an even more favorable MJO phase location and good model agreement.

The current MJO event serves as the best case this season in terms of the “canonical impacts on the extratropics”. The expected wave pattern resulting from convection centered over the Indian Ocean was realized as ridging developed in the both the North Pacific and eastern North America. As the MJO shifts into the Pacific, it will play a role in extending the East Asian jet eastward.  Geostrophically we expect lower heights over the North Pacific and then the canonical downstream wave pattern with lower-than-normal heights over the eastern CONUS. This is bourne out by the latest CFS guidance for weeks three and four.  The resulting hydroclimate impacts are an enhanced probability of colder-than-average temperatures over the eastern part of the CONUS and drier-than-average conditions over a large part of the CONUS, except for the eastern seaboard.  If the MJO propagates through phases 8 and 1, this can support a renewed southern storm track in early FebruarySuperimposed on the tropical variability is another forcing external to the troposphere, namely, a sudden stratospheric warming, which is ongoing whose impacts could potentially amplify those forced by the MJO over the next few weeks.