Archive for April, 2012

Lots of Moisture in the Future….But No Upper Jet Support……Another High Temperature Record For Bishop…Fishing Opener looks “Marvelous” for Both Counties….

Wednesday AM Update:

Just some fine tuning this morning to our forecast…..

Freezing levels expected at 00z Thursday (Wednesday PM) to be 10,500 feet late afternoon then 8700 at 00z Friday (5:00pm Thursday)

The Snow-level today Wednesday is above 9500….then lowers during the early morning hours Thursday to 8500 and then 7000-7500 by Thursday PM.

By the afternoon Thursday little if any moisture will be left. It still look to be mainly a rain event for the high country associated with the subtropical upper low Tonight/Thursday morning.

CRFC gives Huntington Lake .90 over the next 48 hours and Yosemite .65 the same time. So over the crest there could be 6 inches of heavy wet snow by early Thursday AM with possibly another inch or two of fluff on top of that.  This is above 10,000ft.

Based upon the guidance……only .25 to .30 occurs during the day Thursday after Sunrise……IE most of the precip that occurs is associated with the warm subtropical upper low.  It is thought that any backwash or wrap around associated with the southern upper low itself will be too far south of the Mammoth area for any significant up slope Thursday. With all this said, there is still the nose of a 130knot that will be making its way into Northern Ca Thursday late morning. Mammoth is located in the front Rt exit region of the upper jet. So it will be windy beginning later Thursday morning and especially Thursday afternoon. As the upper jet from the northern low translates east Thursday night into Friday morning winds will slowly diminish. The southern edge of the 70 knot Iso-Tach at 300mb is forecasted to be north of the Mammoth area by mid morning Friday. So it will still be breezy over the crest Friday and Saturday as the back side of the long wave remains over the inter-mountain west….but a nice weekend over the lower elevations of Mono County. Light breezes are expect over the weekend at the 7000 foot level with highs in the mid 60s. (Very Nice Fishing Opener) Need warm Jacket when the Flairs go off before Sunrise, then lighter ware late AM and for the afternoon.  Always good to carry a wind breaker for those afternoon breezes.

 

FROM TUESDAY AM:

Here is the game plan…..

The Upper high now over the four corners area will weaken tomorrow morning. Yesterday was again, a record breaking day with another high temperature record for the Bishop area. It was 90 degrees Monday at the Bishop airport which broke the 1953 record high of 88. No records expected today with a high of 82 in the forecast. The High Temperature at Mammothweather was 68 degrees VS Sunday’s high of 71 which was a 20 year record.

Thunder and moderate rain showers developed during the afternoon do to the 2nd of two southerly waves that moved up from Southern California early in the morning.  The wave was stronger than the one that brought rains to Western NV Sunday late afternoon. No doubt that the record heat in the Owens Valley contributed to the lift!  In the Ol’ Http://mammothweather.com rain tip bucket a whole .06 was collected. However, in town to the east, there was much more rain with some water running through the streets.  The Dweebs do not expect another episode like that today. However, some less organized storms may still form over the sierra as a marginally unstable air-mass still exists………

Storms off shore:

Nothing has really changed. However quite the reservoir of tropical moisture well to the south off Southern Baja. Too Bad the majority of all that will not be a player over the next few days…..

Currently the upper closed subtropical low is moving slowly SSE. The upstream kicker will help to open up the the closed low Tomorrow Morning….as at 700mb by 15Z Wednesday a surge of subtropical moisture will flood into Central Ca During the Day.   The Upper jet will be aligned pretty much North/South over Central Ca Tomorrow Am. The Canadian has a VT Max coming through the Central Valley Wednesday. This would be a trigger for rains below 9500feet Wednesday Afternoon. (The Freezing Level is 10,000 Wednesday)  At the 700MB level a closed low opens up into a trof while at 500mb the trof remains closed with the majority of the dynamics staying close to the upper center.  This is one reason why the majority of the precipitation will go to our south as the real jet support with this system is well to our south. In fact, areas from Kern County south to the MX border may have heavy rain!

The bulk of the precip will probably be concentrated right near the upper low itself. This mornings 12z WRF has the upper low and main vort center coming in to the south of TJ, Mex. about midnight Wednesday night.

Now the second system will focus its QPF upon Northern California. The nose of 130knott upper jet comes into Northern Ca well north of the Bay area Thursday morning. The front left exit region is along the Or/ Ca border and the whole dynamic portion of the upper jet including the Rear Rt entry region stays well to our north. By the time the second system comes through little moisture will be left.

The Upshot:

1st system will be rain up to 9500 Ft Wednesday PM as the air-mass will get pretty saturated. Then gradual cooling after midnight will lower the snow level to 8000 feet by Sunrise. Then 7000-ft during the day Thursday. Snow showers a good possibility. As the air-mass dries out Thursday, the spread between the freezing level and the snow level will increase. The Freezing Level on Thursday is expected to be 8000ft so a snow level of 6500 to 7000 would not be unreasonable, however, there will not be much moisture left By the afternoon/evening. I do not expect a General Plow from both system as it will be too warm. Total QPF with mostly rain will be about 1/2 inch. So a lot to do about nothing…..  A few inches of snow is possibly over the lower slopes. The top of Mammoth Mtn might get 6 inches. The town maybe an inch or so…..

Will take one last look Wednesday AM…………..

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.

Roasty Toasty Weekend Resulted in New High Temperature Records Across Eastern Ca and Western NV……Cooler Weather Ahead……Storm Off Shore Splitting and Precip Amounts Dubious This Morning…..

Yes…….Toasty was the word for Sunday and for any day in April for that matter with an official High Temperature record set in Bishop of 91 on Sunday. It has been 63 years since Bishop has reached a high of 90 on the 22 of April, 1949. So 91 is the new record high!

In the high country around Mammoth, we have been keeping temperature records for a much much lesser period. Less then 20 years actually. So yes it was a record as well for Mammoth. And temps were about 20 to 25 degrees above normal.  Today all areas will be a little cooler with clouds and some Isolated thunder possible.  The Mammoth forecast high today is 66 or about 4 degrees cooler. Bishop”s Forecast is 88 today Monday.

Some interesting features on the WX maps the past 24 hours. Pattern over the far west had/has a couple of southerly wave’s aloft that popped some pretty good storms over western NV Late afternoon yesterday with another wave coming through Today. Yesterday’s southerly wave popped a thunderhead over the San Bernardino Mts with the moisture quickly blown off to the NW with more action that developed over the Southern Sierra northeast into west central NV with a few strong storms as well. Of note the wave came through during max heating so it had good thermal support. The next wave is now on shore over Southern Ca and will lift NNE today firing off more convection as well, especially over the Mountains in and around the Mojave Desert. Some isolated TSRW’s over the Sierra possible as well.  The point of interest is that it is April!! And….these are heat enhanced storms from a quasi southerly wave! (Not a true easterly wave)

(Medium Range)

With record heat still forecasted for parts of Nevada, it is still a tough call for the amount of precipitation the Sierra will get. HPC yesterday was very aggressive in bringing as much as 1.7 inches of QPF to the west of the Crest for the Wednesday/Thursday period.  This morning I noticed that CRFC only gives the area west of Mammoth .3 inches through Thursday AM.

The problem is that the heat and the feedback from the surface heating is helping to support the current high pressure system over the Great Basin longer…..probably by diabatic thickness processes. Although the upper high will eventually break down, it will act to help split and significantly weaken the cut-off that is being dragged east by trof to its NNW.  The Dweebs feel that the upper high over the Great Basin will take its toll on the cut off that is currently forming. At the same time, model trends are once again taking the cut off further south into the west coast close to the Mex/Ca border Wednesday night..then lifting it NE through Central AZ. I Will take a good look at the new 12z Monday EC later today….then the 00z and 06z GFS tonight.

Mammoth is in the split between the cut off low to the south and the trof to the northwest. Yes…moisture will be generated as the cut off approaches over the next 36 hours and move into Ca, however it will be just moisture without any significant amount of dynamics this far north. Energy from the system to the northwest is more likely to energize whatever moisture is left by the cut off on Thursday as is it is negative tilt.  So yes, we will get showers but how much is still in question. The Dweebs did not like this system last week and still does not like it today!  Potentially, precipitation amounts could be light…meaning somewhere in the 1 to 6 inch range over the upper elevations.

I will update tomorrow AM.

 

Fishing Opener

What ever happens Wednesday night and Thursday will likely be out of here for a good weather fishing opener Saturday AM. It will be breezy but showers or any measurable precipitation is unlikely at this point. Temps will climb into the 60s on the lake Saturday PM.

 

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.

Warm Weekend Shaping Up for the High Country with Highs near 70….A Few Showers or Thunderstorms possible….Next WX System Possible About Mid-week

Near record High Temperatures are expected for Eastern California and Parts of Central Western Nevada Saturday and Sunday. This would include both Mono and Inyo County. Bishop high temperature records are in the low 90s this weekend. The forecast is for highs approaching 90 by Sunday. The earliest 90 on record for the Bishop area occurred on April 1st 1966. The record for this Saturday is 92 set back in 1950 and the record for this Sunday was 90 set back in 1949. The Dweebs feel that the Sunday record is in Jeopardy of either being tied or possibly broken.

For the Mammoth Area, expect high temps to reach as high as 70 degrees Saturday and Sunday.  TSRW’s are a slight possibility both Friday PM and Saturday PM……As the latest  guidance is showing an unstable air-mass continuing even into Saturday afternoon with the Thermal Trof/Surface convergence over/near the Sierra Friday into Saturday. This surface feature should shift back and forth between Western Ca and the Sierra Crest each day and night. By Sunday the area of surface convergence becomes less focused with a light Zephyr likely developing by Sunday PM. By Monday…..once again the Thermal trof will sharpen up over the great basin and west wind (Zephyr) will grow stronger Monday as the next up stream system moves toward 135w and continues toward the pacific NW. The bottom portion of the upper trof will split, and cut-off on the 23rd.

Longer Range:

Last nights GFS/EC thinking was that the cut-off low would be well south of Mammoth more near either the northern or central Baja Coast, thus not be a factor in our weather mid-week. However….The new 12z Thursday run of the GFS has flipped back to yesterdays AM solution by taking the cutoff inland next Thursday over Southern Ca like yesterday’s mornings solution. This puts the chance of showers back in the Mammoth Area Wednesday PM and Thursday next week…..and out of the area by the opener.

More time is certainly needed to resolve that issue…..As well as the next upstream system for the fishing opener. The new 12zGFS has flipped back to yesterday’s solution in taking the weekend storm east through the pacific northwest leaving California mild and Dry, while the ECMWF is consistent in dropping the vigorous upper trof SE through Northern Ca as a chilly NW slider followed by several impulses that weekend giving the possibility of snow showers.  That is certainly a colder scenario with a more unsettled weather pattern for that opener weekend.

Next Update Monday AM….

As always….the Dweebs keeping you up to date!

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.