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 January 20, 2013
Posted at 12:15 pm by Howard
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:
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.
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
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/
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 February. Superimposed 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.
Friday January 18, 2013
Posted at 9:24 am by Howard
Quick Update Saturday AM:
It was another cold one in the Bridgeport Valley with Bryant Field checking in with a bone chillin -17F at 7:00am. Highs were in the teens yesterday…..
The High temperature yesterday reached 46 degrees at the Village at Mammoth. The low this morning at the Village was 18F, while in the lower elevations of town 9F.
Mono Lake is shrouded in Ice Fog like days before. More of the same is in store for your area with some hope of a break about Wednesday/Ngt. Better odds of flushing the cold out next weekend as a pacific storm blows in, bringing wind and some snowfall for the high country.
The pattern of Ridge in the West and a Trof in the east looks like it may come to an end; or at least for a period of time, later next week as the big eastern trof is forecasted to move out over the Atlantic…opening up the wave length enough to allow a trof to come into California. The ECMWF paints 1.8 inches of QPF near the Crest of Mammoth MT the weekend ending the 26th, while the GFS is a lot drier with the same storm. At least it looks like we will have a reprieve from the current stagnant pattern that is keeping Bridgeport so cold…..along with many eastern sierra valley locations by the following weekend.
Dr Howard and the Dweebs………………………:-)
Lots of worried folks and rumors flying about the end of Winter. From a statistical point of view, the link below will show data to the contrary. Here is a graph that Jan Null, a retired National Weather Service forecaster had recently updated, that shows that Mid Winter Dry Spells are the Norm…Not the Unusual.
Jan is currently a respected, Certified Consulting Meteorologist living in the Bay Area.
The current forecast keeps the ridge in place through the middle of next week.
For Mammoth Lakes, expect Highs in the mid 40s with lows in the teens and 20s.
Light winds in town with Air Quality Restrictions this holiday weekend.
Next MJO update next Tuesday:
Winter’s Severe Cold Snap is Now Broken….Only the Valleys of Mono County Remaining Cold……MJO on the Move!!!
Tuesday January 15, 2013
Posted at 9:40 am by Howard
Quick Update Wednesday AM:
Quasi stationary upper high is located about 150 to 200 Miles west of SFO. At 700MB (10,000ft), it shifts toward Northern Ca tonight as the winds then become more Northeasterly. By Thursday PM, 700MB winds are easterly over the Lip as the 700mb high is centered over Northern Ca. By Saturday and into Sunday the 700MB high is located over NW Nevada and the upper flow at 10,000 will be southeasterly. So winds in town will be calm to light through the weekend and winds over the Mammoth Mtn Summit will be moderate today and then lighter tomorrow then light to moderate through the weekend.
No new snowfall is expected through next Wednesday the 23rd.
Longer Range has the possibility of precipitation between the 26th and the 31st
The high temperature forecast for the Town of Mammoth is 45 to 50 through the weekend
Night time lows will range from 15 to 25 degrees with the coldest temps at lower elevations.
Strong inversions will persist well into next week. This mornings low temperatures ranged from, -9F at Bridgeport to 14.5F at the Mammoth Ranger Station to 21F at the Village at Mammoth. The over night low at the Main Lodge was 25F Degrees and the same over night low of 25F occurred at the Mammoth Mtn Summit.
The high temperature yesterday in Mammoth was 45 degrees…..
Again…..Moderate winds this morning over the top of Mammoth Mtn were blowing about 55MPH out of the North. They will diminish a bit Thursday as they shift and become easterly at the same time. By Friday, the 700MB high is forcasted to be more over NN Eastern Ca and the winds become ES-Easterly and pick up slightly.
Overall beautiful weather for the next week!!!!
Note: Gusty NE winds of 50MPH are blowing over the top (lip) of Mammoth MTN this AM. Wind speeds are much less over the lower slopes.
Wow! What a cold snap! The last three to four weeks will be memorable. Temps ran -20 to -30F last weekend in many valleys areas along the highway 395 corridor. Mammoth’s temps bottomed out at -5F at the village yesterday AM while at the corner of Main Street and Old Mammoth Dr -9F. This morning, waht a difference. Temperatures were some 20 to 25 degrees warmer, with a low of 15F here at http://www.Mammothweather.com at the 8200 foot level.
The freezing level over Yosemite that was about 1000 feet yesterday, rose to 8300 feet this morning and will jump to 12,500 by 4:00pm today! Highs will be in the low to mid 40s today at 9800 feet while the valleys under the inversion will be in the 20s at best. By tomorrow, the inversion tightens up further and the valleys will get even colder while the upper elevations continue to enjoy 40s for highs. Lows at night will be mostly in the 20s, but could be colder in the lower elevations of town. If the inversion gets squashes to 7500 to 7700 feet. The Village at Mammoth could be near freezing for a low while at the Trails Subdivision, it could be in the upper teens to low 20s.
Ok, enough about inversions. Only one more issue to mention. Its been below freezing including in many garages in Mammoth for days. Once temperatures warm up, frozen pipes are going to thaw and water problems may become an issue for many around town. If your water is left on at your vacation home and you live out of the area, make sure to check with your absentee home caretaker to make sure you do not have broken pipes. Many frozen pipe problems are not realized until the weather warms up outside. Then, if left days or longer, you can have some real interesting things begin to grow in the walls! ;-)
During the first week of January, a rapidly intensifying MJO developed in late phase 4, while the GWO showed relatively low AAM. (Atmospheric Angular Momentum) AAM is on the increase and the MJO is shifting east. The MJO is now in the early stages of Phase 7 of the MJO phase space. There has also been an important Kelvin Wave associated with it. http://www.esrl.noaa.gov/psd/map/images/gcm/gwo_40d.gif
The global models and ensembles including the EC, GFS and Canadian have been in the past several days, containing the MJO in its current location. See: The EC ensemble prediction model: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/EMON_phase_51m_full.gif However, the statistical model See: http://cawcr.gov.au/staff/mwheeler/maproom/RMM/fcsts/pd.MW05.Last.gif Keeps the MJO moving right on through Phase 7 & 8. At the same time, AAM is currently showing an increase.
Comment from the CPC: Extratropical impacts of the MJO are likely to remain important over the next couple of weeks as the diabatic heating serves as source for downstream Rossby wave propagation. Should the MJO propagate through phase 6 and into phase 7 as predicted, it could force a jet extension into the Pacific with important downstream consequences for North American hydroclimate through the end of the month.
Dweebs Comment: The MJO shifting through Phase 7 and into Phase 8 moves the tropical forcing beyond the dateline toward the Hawaiian islands. This process often times serves to extend the Asian upper jet east. The upper jet eventually splits, during the process of retrogression of the blocking high, that is currently setting up over the far west. The northern branch of the jet on the eastern flank of the upper high becomes confluent with the southern branch which undercuts the retrograding upper high. The is the scenario for the classic “pineapple connection” which is more likely to effect the pacific northwest 1st, then over time shift south to Northern Ca then sometimes Central Ca.
This is what the Dweebs will be most focused upon over the next week. “This is not a forecast”, but is a serious consideration. The other features worth noting will be the other teleconnections which will play a part to either support or suppress such possibilities.
One thing is certain, we here in the high country are done with frigid weather for a long time!!!
Dr Howard and the Dweebs…………………………..:-)