Archive for year 2012

Warm…Breezy…Dry Weather to Continue Through Weeks end, with the Coolest Day Saturday……Some Old Hurricane Debris May End Up Over Central Ca About the 4th…..

Latest guidance through the last few days of August shows the weather in Mammoth ending on a warmer then normal note. Highs at 8000ft should continue in the mid 70s. It will be exceptionally dry and quite breezy as well. The 12z GFS has heights at or above 588DM through 12z Wednesday then lowering a bit south of 582Dm by Saturday with the possibility of a dry cool front coming through during the day.  So Saturday will be a breezy one with high cloudiness and possibly some Alto Cu as well. The High temps may cool to near or slightly below 70 at the village.  Overall, a nice late Summer weekend with near seasonal temps, except Saturday. Lows Sunday Am in the 30s.

This is the time of year the climatically we could get some dying Tropical storm moisture coming up from the south or SSW. There are currently TS’s over the eastern tropical pacific. One the will move NW off the Baja coast later this week.  Some times we can get showers from these if conditions are right.

Looking at the EURO for the next 10 days. The trend for above normal temps is certainly there through the end of the 1st week of September. So locals enjoy!!!  To bad that most of the festivities will be over after Labor Day.  If you believe in the CFS 2 experimental charts, somewhat above normal temps will continue more often then not….right on through a good part of September!!  That means that high temps will be mostly in the low 70s for the month of September.

See: TEMPS  http://www.cpc.ncep.noaa.gov/products/people/sweaver/cfs_fcst/images1/wk3.wk4_20120827.NAsfcT.gif

500MB Anomalies http://www.cpc.ncep.noaa.gov/products/people/sweaver/cfs_fcst/images1/wk3.wk4_20120827.z500.gif

 

By popular demand……My 1st best guess

 

Some very early thoughts about the upcoming winter:

1. CFS 2 model continues to back peddle on the strength of EL Nino indicating that by Winter it may actually end up either a weak El Nino or a La Nada Winter.

See: Latest CFS #2 : http://origin.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd3/nino34Mon.gif

Check out Precip Anomalies:  http://origin.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd3/nino34Mon.gif

Model says Feb, March and April best precip months?  Keep In mind that this is an experimental model.

2. What about the MJO?  That is the maverick that could make all the difference this Winter as it has an notably stronger effect odds wise, during Weak El Ninos…La Nada’s and Weak La Nina’s,  which this winter will most likely be.  IE. there may be relatively short periods of intense precipitation over the Sierra this mid to late Winter.

3. The QBO is currently in its Easterly Phase for about the last 12 months, typically weakening the build up of cold air over the Eastern half of Canada last winter. That will change with the oscillation flipping back to westerly by years end or next winter. (More favorable for blocking pattern with import of Arctic Air 1st over the west by late Fall, then via the Great Lakes about January.

4. The PDO remains negative…in the cold phase.

5. And because of all the warm SSTA’s around Greenland the NAO will be more likely negative leading to more blocking and meridional flow (IE North-South near or around the Davis Straights. That is contrary to last winter. So it will tend to be a colder winter east of the divide.

6. There is A LOT! of warm water piling up in the NW pacific with the warm pool north of Hawaii appearing to redevelop further west. This will re-inforce the -PDO with time I believe. So the -SSTA’s over the Eastern Pacific may actually grow stronger again later this year.

The Dweebs at this point are not particularly enthused about an El Nino winter for Ca. The Split Flow pattern with the enhanced Subtropical jet normally associated with El Nino may be quite incipient and Maladroit in behavior.

My gut feeling is that at this point, the winter looks wetter then last, over all;  near or a bit below average precip which is usually a good winter for the Sierra, depending upon how early the storms hit.

Will Update in October or sooner if warranted.

 

PS… Whether a weatherman is right or wrong with a long range forecast…becasue of so many variables, any person can be right, for all the wrong reasons…….

 

The Dweeber…………………….:-)

 

 

 

 

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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.

Weak Subtropical Ridge Builds into California Today for a little Warming…..A bit stronger West Coast Troughing Expected Next Few Weeks….So the Far West Portion of the Monsoon will end for the Central and Northern Sierra……

Quick Update Monday AM:

No change in the current pattern Sensibly…  Trofing off shore will eject west Tuesday night for a bump up in the SW flow aloft. So it will be a bit breezier Tuesday. The outlook for the week is for very dry conditions with slightly above seasonal highs.  Expect is mid to upper 70s in Mammoth through the holiday. Night time lows in the upper 30 to low 40s. SW breezes to 25 MPH. No precipitation in the forecast for the next 7 days.

It may warm up a bit next week as models hint at a westward shift in the upper ridge.

 

 

The Dweeber………………….:-)

 

Although a flat subtropical ridge is building into California today….the guidance is showing more troughing off shore over the coming weeks as we move through late Summer.  Daytime highs now in the mid to upper 70s will a drift a bit lower later next week. As a result, there may even be some night time lows in the 30s in the drier air after mid-week. Needless to say, with a stronger southwest flow aloft, monsoon moisture will be shunted to the east next week, well south of the Central Sierra. Furthermore…..Longer range suggests that because the western periphery of the subtropical ridge is coming at us from the southwest…..the AZ Monsoon is pretty much over for the Central and Northern Sierra for the next week or two. By then, the Climo suggest more troughing anyway.

So…with the exception of a maverick closed low split off from an approaching west coast trof, drifting across the Sierra to the south of us, or moisture from a dying hurricane headed north…….Thunderstorms if any, will be very isolated over East Central Ca.

Daytime highs now in the upper 70s will drift lower next week and remain mostly in the Mid 70s then during the first week of September drift into the 60s for a time, as stronger troughing moves through California around September 4th.

 

The Dweeber……………………………………………:-)

————————————————-
Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.

Weak Spliting off shore trof will allow a small upper low to drift through Southern Ca Wednesday/Thursday…..Expect a brief period of Airmass Modifacation to develop Wednesday for some Showers and Thunder…..Rest of the week looks dry with slightly above normal temperatures……Then Southerly Flow may move back into the Southern Sierra about Mid-Week………

Quick Thursday AM update:

Looking at the short,  medium and longer range Guidance…..Monsoon season for the Central Sierra may be winding down. The guidance is showing more troughing in the extended for the west coast which will tend to keep more of a SW flow aloft over the Sierra. This is a dry pattern for the most part. That is unless another of those little buggers closes off and comes in like yesterday.   Even so, PWAT will likely be less.Expect fair weather for the next 7 days with afternoon breezes into the evening hours.  Highs in the mid to upper 70 and lows in the 40s.

 

Longer range shows below normal temps beginning just after mid Sept associated with stronger trofing off the Pacific North West coast..

 

The Dweeber……………

 

 

Wednesday Am Update:

It was a pretty sleepless night last night as numerous thunderstorms developed over the southern sierra then moved over the south central sierra at about 1:30Am. This occurred as the weak upper level low that was supposed to come in over Paseo Robles came across Monterrey Bay last night…..Dynamic forcing, strong UVM and upper divergence occurred over the southern and south central sierra. Mammoth picked up .29 hundreds of an inch of rain and there were over 310 lightening strikes recorded over both the west side and east side of the Sierra. Certainly not good news for fire agencies…..

At this time, the upper low at 700mb is centered over the south central San joaquin valley. However dynamic forcing associated with the cyclonically curved upper jet has now pretty much moved into Nevada.   So isolated storms will be generated by heat today VS dynamically driven last night.

It will begin to dry out tomorrow Thursday and be fair through the weekend with highs in the upper 70s…..lows in the 40s.

 

The Dweeber…………………….:-)

 

 

Latest guidance is showing a split developing in the off shore upper trof. Latest 06z GFS has the upper center crossing near Paso Robles, Ca Wednesday AM,  between 12z and 18z.  At 500mb the upper center is 584dm. The track should take it SE through Kern County and the Mojave desert,  throughout the day Wed and into Thursday…..exiting about noon Thursday through the Ca/NV/AZ borders.

As the low approaches the coast late tonight and Wednesday morning………a rapid increase of southerly flow is expected into the southern Sierra and extreme south Central Sierra. Moisture and dynamics will briefly increase chances of isolated showers and thunderstorms. The deepest moisture should remain to our south over Southern Inyo County….then SE over San Bernardino counties. This looks to be a one day event for the high country of Southern Mono County as drier air works back into the high county Thursday. Temperatures will cool slightly to the mid 70s. Lows in the upper 40s.

Outlook through the rest of the week looks pretty nice with highs back near 80 with lows in the mid to upper 40s. Expect the usual afternoon zephyr breezes.  Next change in the pattern begins to develop the very end of this week or the following Monday as the upper high over the four corners redevelops and the toasty 594Dm at 500mb height line pushes west into SE California again this summer.  Monsoon moisture may surge one last time into the Southern Sierra for isolated TSRWs about the middle of next week with high temps back into the low 80s as we finish off the rest of August on a warm note……

 

 

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

 

 

————————————————-
Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.