Mammoth Mt Receives 18 to 24 inches from the biggest cold storm of 2015!…and over a foot at the Village at Mammoth…..Beautiful weekend for skiing shaping up……The Next Storm about the following Tuesday!

Thursday 6:15 PM

Warming trend in play with lots of high clouds due to the splitting system off shore.  No real changes to the forecast other than to add some CU over the Sierra early in the weekend. There is a chance of snow showers Tuesday/Ngt.. No big deal though…The rest of next week looks fair.

At this point I do not see any major storminess in our future. Both 6 to 10 and 8 to 14 day outlooks are dry.  Beyond week 2 climate wise, it is getting pretty late in the season for a major storm….  The Dweebs will keep the faith for one or two more cold systems.  We have had decent snow producers in May historically, but they are not all that common, especially with all that anomalously warm Eastern Pacific Water. (+PDO)

 

The Dweeber……………………..:-)

 

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As the cold pool shifts east today and the clean up finishes up this afternoon, the Dweebs must remember that the QPF for our area in the sierra is often under estimated when;

1. You have the upper flow natural to the sierra.

2. A strong cold front with a lots of UVM ahead of it.

3. Good upper divergence over the area

4. Most of all….A cold pool capable of heavy convective showers following the front.  The heavy convective showers last night brought another .5 inches of H2O to the mountain and another 6 inches of snow. This was more than earlier forecasted by all forecasters early Tuesday AM for our area.  I will say that I did update between 2PM and 3 PM yesterday afternoon after looking at the latest RHHH “Rapid refresh model” when it was evident that heavy convective showers were headed for the Central Sierra during the night. We received 1 to 2 inch per hour snowfalls.

 

Forecast….

Partly cloudy during the afternoons the next few days with a warming trend into the weekend. Expect about 8 degree of warming over the next few days through Friday and then upper 50s over the weekend.

 

Longer range:

I personally like the next system better than some of the other Dweebs….    As although the models have the next system to be more of a northwest slider, to me it looks like it will have the potential to dig further west with time as the upper jet has a good temperature gradient as it digs south..  This is not to say that it is impossible for the current NW slider to continue into the shorter range. I am just beginning to see some bias more to the west.  Stay tuned….as this may end of being another decent April Snow Producer about Tuesday next week…..

 

El Nino:  It should be acknowledged that most climate scientist’s at this time are doing a great job of not hyping the developing El Nino over the EQ pacific. They were badly burned last year with the Modoki that set up leading to a winter similar to 1977.  This Dweeb does not want to hype it as well. However, there are some interesting observations that one should consider. There are some differences between where we are this year at this time as compared to last year at this time when it comes to the temps over the NINO basin.  Last year, there was a rather large Kelvin wave that surfaced over the eastern pacific. This year at this time we have the same scenario. IE Another very warm KV surfacing in the same area.  However, the big difference this year is that there are antecedent conditions that are much warmer already in the Nino Basin. The KV now surfacing will only add to that heat in the basin.  The average SSTA for the 3.4 region of all models is now “Forecasted to be 1.5C by *August.  That is within the moderate El Nino threshold. However, August is not December, January and February. A lot can happen 5 months later…. Nevertheless, the odds of reaching the moderate threshold temperature wise is very possible now by August.   Remember that for an El Nino to be classified as moderate,  it has to remain at about that threshold in the Nino 3.4 region for at least 3 months….

Some additional thoughts…

The record setting  MJO last month was able to move a lot of warm water eastward toward the EP.  The MJO space space shows it to reemerge out over the Indian Ocean. However, the signal may be related to low frequency noise due to either KV or RW action…  The Dweebs are questioning whether the MJO will strengthen enough to excite twin cyclones again, pushing more warm water eastward toward the eastern pacific later this month and into May…..thus bringing further warming to the Nino Basin.

The current KV now rising is amazing warm!

 

* http://www.bom.gov.au/climate/ahead/model-summary.shtml#tabs=Pacific-Ocean

 

 

 

Colder Weather Ahead With Snowfall in Our Future……Its official…..The Winter of 2014-2015 is Driest on record…..

Wednesday AM:

 

Totals 14.5 inches at Mammoth Weather.com at the 8200 foot level and 18 to 24 inches on Mammoth Mt. Including the crest.

 

Tuesday PM 11:00PM

As mentioned in my afternoon report below, snowfall continues to pile up due to the nature of this storm and the cold pool aloft. Heavy convective snow showers have increased accumulations to 18 inches at 11:00PM at the Main Lodge. At Mammoth Weather.com. 14.5 inches has fallen and it is estimated that a good foot has fallen in town.  Snow will continue to fall but gradually diminish after Midnight as the cold pool shifts east through the Great Basin. Another inch or two is still possible the rest of the night. Tallies in the Morning here at mammothweather.com…..

 

Dr Howard and the Dweebs……………………….:-)

 

 

Tuesday PM 2:45pm

We are doing well here in Mammoth with about 8 inches here in town. Snowfall is S+ and so 1 to 2 inches an hour falls are occurring.  Mammoth Mt has picked up 12 inches at the Main Lodge with .75 inches of water.  We still have a way to go and so the Dweebs will jack up total amounts possible up to a foot now in town by late tonight and 15 to 20 inches over Mammoth Mt.  The tricky part is that although there will be a break later this afternoon, there are some convective bands within the cold pool that will come through the sierra tonight. If a band happens to come through Mammoth Lakes,  2 inches per hour snowfalls could occur over night.

 

Quick Tuesday AM Update:

Although our storm is moving a little slower than earlier thought.  The HRRR model (Rapid refresh model) has the front, currently climbing the sierra and should begin to bring some light snowfall to the Crest “around” 9:00AM. Thereafter, between 9:00am and 10:00 AM the leading portion of the front will push east to near highway 395.  Expect snowfall to continue though mid to late afternoon….  There may be a break later this afternoon in the precip….The cold pool moves in tonight and so the snowfall will become more showery in nature with convective showers early and even the chance of some thunder snow this evening.   Expect amounts in the 4 to 8 inch range in town with about 12 inches over the upper elevations by Wednesday AM. Expect high temperatures in town today in the mid 30s with temps some 10 degrees colder on the Mountain. Lows tonight in the teens…

The weather will become fair by Thursday with milder temperatures.  Seasonal temperatures will prevail this weekend (50s) There may be some wind over the upper elevations over the weekend…

The next weather system will be about Tuesday or Wednesday next week…..That one looks especially cold and showery….

 

Quick Update Monday AM:

Everything on track for a moderate precipitation producer. No attached “AR” to tap into, however the eastern pacific is plenty warm and I would imagine that evaporation rates are extra special these days because of the warm EP. Back to the current system…..We did get the flip in the PNA as expected by the MJO in phase 3.  So here we are with the first cold trof of this new season….or this year? The upper jet favors Mono County and so Mono will get the bulk of the snowfall over the crest.  CRFC has about 1.04 for Yosemite. The GFS has about an inch as well. So given 700MB temps, good orographic’s and some decent UVM,  expect somewhere between 10 and 15 inches for Mammoth Mt. and some 4 to 8 inches in town.  It will be blustery Tuesday with highs in the 20s on Mammoth Mt and mid 30s in town.

It will remain showery Tuesday night possibly Wednesday afternoon as 700mb winds back a bit from the NE during the PM for a little upslope.  Thursday, will be warmer sensibly with much more warming coming in Friday into Sunday. There appears to be a split in the flow that allows a small low to come into the west coast about Ensenada Monday. That appears to be too far south for Mammoth, but may bring the chance of showers to Southern CA, early next week.   High temps will climb from the mid 30s on Tuesday, to well into the 50s over the weekend, Winds with the split flow over the weekend look pretty light…..

Next chance of precipitation later next week….

Kelvin Wave:

Boy!  What a Kelvin Wave!  Now surfacing along the equator of the Central American coast.  The whole wave is slowly rising with the nose of the wave 1st.  The Nino 1+2 region spiking an anomalous 1.5C  The Kelvin Wave subsurface temps are better then +6C!!  The Dweebs expect the anomalous sub surface waters to continue rising and warming the Nino Basin….   A surge of warmth from the south is also possible over the eastern pacific…this all leads to a good chance of a moderate El Nino by Summers end….

 

Dr Howard and the Dweebs……………………….:-)

 

Thursday AM:

The 2nd dry WX system, in a series of weather systems, has managed to bring 20 to 25 degrees of cooling to our region as compared to high temps earlier in the week.  Snow Showers this morning will lead to clearing this afternoon……No significant accumulations expected…There are two distinct future weather systems that are both stronger and deeper than the ones that came through bringing cooling and breeze to our region the past few days.

Sensibly, it will be colder today with highs in the mid 40s near the village. However, it will be milder Friday into Saturday as weak short wave ridging builds over the area. On Sunday it will be breezy to windy and colder with increasing clouds and the possibility of some light snowfall developing from the next system. The timing appears to be later Sunday afternoon and into Sunday Night as well as Monday AM. Amounts look light, with less than 6 inches over the crest and possibly an inch or two at the village by Monday AM.  Sunday will be cold with highs in the upper 30s!

It is the following system that is of most interest with a stronger and a more dynamic upper jet moving into Central CA. There appears to be the possibility of a foot over the upper elevations and some 3 to 6 inches in the Town of Mammoth, Tuesday into Tuesday night.  The ECMWF is wetter than the GFS. Well have to see how they handle the QPF in the coming days.  Both models show yet another system moving toward our area, prior to or early the following weekend. Although the new improved ECMWF and GFS handle it differently…..

April does look more unsettled from a climate time frame with more weather systems bringing the chance of more water to our parched region…….

Mammoth Pass:

The DWP snow survey was completed yesterday April 1st. It is as dismal as it has ever been historically.  This is “The driest winter on record” as reported by DWP. The manual measurements taken yesterday at Mammoth Pass showed a water content of 1.4 inches or 3% of the April 1st norm of 43.5 inches of water in the snow.  Mammoth Lakes itself had 0 and so 0% of normal. The Minarets 2 site had an 1 inch.   So the Mammoth Lakes Area averaged .8 inches or 3% of normal. The average of all snow courses south to Cotton Wood Lakes, down though the Southern Sierra was not much better,  with an average of 4% of normal over-all.

NASA has indicated that this particular 4 year drought is a once in a 1000 year event because of its severity.

Kelvin Wave:

The Dweebs just had a look at the updated Kelvin Wave that’s axis is near the Date Line.  In the front of the Kelvin Wave you have down welling of Warm Sea Surface temperatures and in the rear you have upwelling of colder SSTs rising to the surface. The Sub Surface SSTA are greater than +6C!   This is a magnificent KW that will warm the Nino Basin later this Spring and into the Summer. It will also push warmer water up north through the eastern pacific and result in warmer SSTA anomalies along the west coast.  It will be interesting to see how the +PDO reacts this summer, by watching that teleconnection indice this Summer. I will report monthly on that throughout the year.

This KW will most likely result in enhanced possibilities for the return of El Nino later this Summer and Fall.  However, once again like last year, will there be “carry-through” into the next winter or,  will it end up being another Modoki Event with a split flow pattern and more Eastern Pacific Blocking.   No one knows….Even the “Shadow”doesn’t know this one……  For you young folks that do not know who the Shadow is….Ask your parents…..if they do not know, ask your grand parents……or just Google it!

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

After another very warm day Monday….A slow change to near season temperatures will occur this week with periods of wind beginning Tuesday……Pattern Change this Week will Continue into the Following Week with MJO Support…..

 

Tuesday AM:

No changes for the short-term with winds already up in the high country and cooling moving in. It will be breezy in town (TOML) both today through Wednesday with a high near 59 today and mid to upper 40s Wednesday. Night time lows will be in the teens in many areas by Thursday AM.  The weather system responsible for the cooling will brings rains to the pacific NW and as far south as Northern CA.   A secondary impulse will bring a slight chance of showers to our region Thursday AM.  After that, a break in the pattern of wind before another stronger Trof brings winds and cooling back into our area by Saturday night and Sunday with wind 1st and then cooling Sunday into Tuesday.   At the Moment, the favored global models are at odds with each other with the GFS Pretty dry and further north with the Sunday -Mon system, while the Euro continues the threat of snowfall for our area early next week. With that said, the EC did trend drier over night and I guess you could say more toward the GFS solution.  So the system for Sunday Monday does not look all that great for snowfall at this time.  However there is plenty of time for an adjustment either way. The Dweebs should have much better confidence by Thursday for the Sunday-Monday system. Evidentially the pattern will take more time to develop and thus the next storm cycle is most probably further down the road but not out of the question in April.

Mammoth Pass:

There was a depressing report that came out from the DWP this AM.   The updated telemetry showed an inch of water up on the pass. I am sure that they will go up and measure what there is to measure manually today or tomorrow on several areas around the pass to come up with an average or the mean. I do not know which they use. 

1 inch of water in the snow pack at this time is equal to 2% of the normal water in the snowpack for April 1st. That is deemed to be the end of the water year here on Mammoth Pass.  As a comparison, the driest year on record showed MAMMOTH PASS with about 10 inch’s of water in the snow pack.  You do the math…..

This is not only the driest year on record for April 1, but possibly a 1 in >100 year event.  Just think, you were alive to experience history from a hydrological perspective.  As a comparison, at the opposite end of a time scale, this is probably equal to or greater than a winter of

>300% of normal on the opposite end of the scale, or the equivalent to the projected historic ARC storm winter that may hit the sierra some day or a 1000+ inch winter. The infamous winter of 1969, the greatest winter on record according to DWP records going back to 1940 was 277% of normal. There are plenty of photos around town with the famous areal shot of the Main Lodge being close to buried. That winter is the high bench mark of all winters here in Mono County according to DWP records. I will also add this. Although the siege of storms began the 10th of January of 1969, there were plenty of good storms during the month of December 1968. I have researched the re-analyses 500MB and 250MB charts on that winter…….

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Most astute WX folks know that model reliability is poor during times of pattern transitions. Especially in a drought year when there is the “possibility” of a pattern of wet and cold in a year of warmth and dryness. After looking at both the deterministic runs of the global models this AM and well as their ensemble members in seeing a pattern change for next week, one would look for other supporting evidence.  Such evidence like the forecast of key teleconnection indice changes and other areas of support like the MJO within the Wheeler Hedon, phase space. Using the MJO to see where it is geographically, its strength as well as what and where both the dynamic and statistic models both locate it. The signal is tricky as it can be convoluted with other modes of lower frequency variability like kelvin waves and ERW which can constructively phase or destructively phase with the signal.

After the current episode of the MJO reached record strength on the 16th of March…it has weakened, but still remains a significant signal as it re emerges out over the Indian Ocean with a sigma of about 1.5.   It is commonly accepted that when an area of enhanced convection moves over the Indian Ocean beginning with area 70E along or near the Equator south of a meridian that runs through Pakistan, then progressing east through the Maritime Continent and into the far Western Pacific to about 120E there is a “tendency for a Negative PNA state” or a long wave trof is biased to the far west of the CONUS.

What is interesting at this time is that:

1. The ECMWF model has a long wave trof carved out over the Far West next week coinciding with the forecasted location of the convective state of the MJO in phase 3. The Statistical model keeps the signal going into phase space 4, however the dynamic models weakens it rapidly thereafter….

2. This is the first time since last year that a moderate signal is forecasted to move through Phase 3.  IE this has not happened in over 3 months. Although contrary to the dynamic models, it may hold together strong enough well into Phase 4 based upon the Statistical Model.

3. The Dweebs use the MJO at times for validation for the week two and week three-time periods which is more related to an interseasonal time scale. This is all in an outlook period or beyond any forecast time frame. So the idea of a wet week next week is a good idea, but too far out to be an actual forecast. Nevertheless it is nice to see last nights run of the ECMWF showing between one and two inches of water EQ for the Sierra west of Mammoth next week up until the 9th.

 

The forecast for this week shows a gradual cooling trend beginning tomorrow Tuesday through Thursday. There will be periods of wind and we will see the return of over night freezing temperatures on a regional scale by Thursday AM. Daytime highs will be in the 40s on Thursday.  The following holiday weekend looks mild with the winds coming up on Easter Sunday.  It is what happens beyond Easter Sunday that holds the possibility of a stormy pattern that following week…..  (Week Two)

To reiterate my last discussion, there is the potential of the First Significant Cold Storm Cycle this year….next week depending upon how everything sets up including the timing……..   The new 12z ECMWF that is just finishing through 240 hours is looking more bullish today……I will comment further on this outlook late this afternoon….

 

Stay tuned>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

 

The Dweeber…………………………….:-)