Archive for January, 2019

The last but not least of the 3 sierra storms getting ready to hit the high county by Tonight…..Winter Storm Warnings hoisted with a special emphasis on Blizzard Conditions later tonight! A break in the Weather is expected Friday and Saturday with another smaller system expected Sunday night….Next week looks dry with milder temps….

9:00Am Thursday AM Update:

Mammoth Mt Reports 24 hour snowfall amounts up to 4 feet of fresh snow. Winter Storm Warning is in effect until 4:00AM Friday. Upper elevations for the period 4:00AM this morning through 4:00AM Friday could pick up another 1 to 2 feet for a total 5 day snowfall of between 7 and 8 feet over the Mammoth Crest.

The Eastern Sierra Avalanche Center in Mammoth Lakes has issued a BACKCOUNTRY AVALANCHE WARNING:

* TIMING…In effect from Wed 6 PM PST to Fri 7 AM PST.
* AFFECTED AREA…The eastern slopes of the Sierra Nevada mountain range between Virginia Lakes on the north, to Bishop Creek on the south.
* AVALANCHE DANGER…The avalanche danger for the warning area will rise to HIGH tonight and will remain at HIGH thru tomorrow and tomorrow night.
* REASON/IMPACTS…Heavy snow combined with wind will result in widespread avalanching.
* PRECAUTIONARY / PREPAREDNESS ACTIONS…Very dangerous avalanche conditions. Travel in avalanche terrain is not recommended. Avalanches may run long distances and can run into mature forests, valley floors, or flat terrain.
*As a note, Mammoth Mt is an avalanche controlled area with snow safety devises that is much safer than the outlying back country area.

Cold Unstable air will bring periods of heavy snow today. Snowfall amounts at the Village could add another foot+ to last nights accumulations. Friday will have improving conditions with the chance of snow showers and light snowfall accumulations. 1-2 inches. Saturday looks partly cloudy and dry. Another but weaker storm may bring another 1 to 5 inches of snow to the 7000 to 8000 foot level and between 4 and 7 inches to Mammoth Mt by Monday AM. The remainder of the new week looks dry and milder….Excellent week ahead!

Next possible stormy period beginning about the 1st of February.

Note: El Nino has not yet coupled with the overlying atmosphere, over the tropics. The current pattern is being modulated possibly by the MJO. The Dweebs are expecting a highly amplified pattern developing later this new week which “may” end up with an under cutting of the westerlies by the first week of February. The Dweebs main focus will be on this possibility and will watch and report on its development next week for the longer range. Dr Howard and the Dweebs…………….:-)

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As of 1:00PM; winds were pretty steady over the crest of Mammoth Mt with 65MPH, gusts 75-80MPH; In town, winds were SSW 15 to 30MPH. SFO Radar showing leading band of Precipitation already on shore over the Bay Area with pockets of heavy rain now occurring. Snowfall is into the Northern Sierra south to Alpine County. Looks like there is a small band of showers over the Sawtooth Range west of Bridgeport, CA.

The Updated HRRR model begins snowfall over the Mammoth Crest about 3:00PM with snowfall increasing in town around 4:00PM. It will be light…..

Winds will steadily increase this evening as a 970MB surface low west of Northern CA heads towards the Pacific NW.
PWAT within the storm is approaching 1.2-1.3 inches over our region by Mid Evening Wednesday. 850mb winds from the south-southwest will increase to 50-55 kts. This strong flow will combine with high moisture content to produce onshore IVT values of 750-850 kg/m/s, categorizing this event as a strong atmospheric river. Copious amounts of precip will occur tonight into the early mornings hours here in the high country. Expect a good four to five feet of snow over night over Mammoth Mt with 2.5 to 3.5 in the Town by Thursday evening. Most of this will fall tonight into Thursday AM.Local Blizzard conditions will hit tonight and continue into thorough 4:00AM Thursday. Snowfall will wind down Thursday evening…..The weekend looks partly cloudy with highs in the 30s and lows in the teens. Another smaller weather system will bring light snowfall Sunday night….Then a long break of a week or more…. PS…this is no El Nino…..So far the convective effects of El Nino has not awakened…..

Dr Howard and the Dweebs…………….:-)

Series of Storms headed for Central and Southern California…Wet Pattern but no El Nino……

Drought Stricken California will likely pick up a Bonanza of rainfall next week, as the next series of storms hits predominantly the southern half of the state. The first in the series hits the South Central Coast Tonight with the focus unfortunately on many of the the burn areas. Being that the storm is coming in predominantly negative tilt, there will be a lot of Convection, which means Thunderstorms with localized areas of heavy rain. The focus areas along the coast and inland seem to be from Malibu NW to Venture County and just northwest. However, most areas will get their fair share. Folks that live within and below the burn scar areas should pay close attention to the statements from the National Weather Service.

C7 day totals issued by the WPC this morning showed between 4 to 7

inches of rain over a 7 day period in the coastal mountains North and East between Malibu to East of Pt Conception.

EL Nino:

Although the storm track appears to be coming in from a more southerly latitude, there is actually a split in the flow due to ridging over the Rockies that is forcing the storm track into Southern CA. That will begin to relax by the middle of next week. This will allow storms to hit the Central Sierra better mid week. As far as El Nacho goes, there is little or no evidence that El Nino has anything to do with the rain that is coming to Southern California over the next week. Why? Just take a look at the area between the Dateline and south of California to and along the equator. There is little evidence of large scale coupling of significant convection over the Nino Regions and the overlying atmosphere. The convection is average at best. Only a pocket along the dateline. In my opinion, these are just good old fashion west coast January storms! BTW..Expecting Mammoth Mt to pick up another 4 to 6 feet mid week. Snow is possible for parts of thr Owens Valley as well the upcoming week,

Dr Howard and the Dweebs………………….:-)

First in Series of Sierra Storm drops 16 to 24 inches of snow Saturday and Sunday with Winter Storm Warnings hoisted for Sunday afternoon and night….Dangerous Travel conditions expected for the Trans-Sierra highway later this afternoon and tonight as heavy snow and high winds combine for full on blizzard in many areas of Highway…..

6:20pm Update: Snowfall rates have increased in the Town of Mammoth with about 4 inches of new on the ground. We are expecting between 1 and 2 feet between the Town of Mammoth and the Mammoth Crest by Morning.

Winds:
The prime time for high winds will be after 9:00-11:00 PM as precipitation rates in Mono County diminish and simulated soundings show inversions lowering to near mountain top level. This creates a better opportunity for downsloping. Weather Balloon Soundings indicate 70+ KTs below the inversion, so local gusts in wind-prone areas along Highway 395 (South of Coleville) could reach 80 mph.

From 10:00AM Sunday; The Village at Mammoth has picked up about 16 inches of snow since 10:00AM Saturday….Snowfall amounts blew through the forecasts of less than a foot. Mammoth Mt picked up between 16 and 24 inches during the same time period.

Next weather system is associated with the dreaded NW jet. However, there is enough westerly bias to bring us a period of heavy snow over a 12 hour period to warrant Winter Storm Warnings for this afternoon through the night.

Not only will this storm bring a period of heavy snow, but more importantly very strong and life threating winds that will cause blizzard conditions late today and tonight along with zero visibility. Although some roads will likley close in exposed areas later today and tonight….do not plan on any travel without, warm clothing, warm blankets, water and food. Remember in zero visibility, you can become disorientated very quickly. If stranded in blizzard conditions…stay in your vehicle, do not wander out…