Tuesday May 21, 2013
Posted at 7:45 am by Howard
Wednesday AM Update:
An upper trof over Oregon this morning is providing the gradient for WSW winds to continue. Upper Jet still favorable for wind gusts to 70MPH over the upper elevations and gusts to 40MPH in town. It will be a cooler day today with highs in the mid 50s and nighttime low will dip well down into the 20s by AM. Although the upper flow will remain westerly over the Sierra, the upper trof that is stuck over the Pacific Northwest due to the stationary ridge over the Midwest will begin to lift NNE away from us. So the height rises this weekend are due to that action, rather than any ridging from the west. What this means is that no doubt there will be another trof that will effect us early next week with more wind and cooling.
Yesterdays discussion highlighted the strong possibility of early Summer type heat coming to stay over the far west. That still looks good for an end to Spring weather wise. However, the persistence of trofing will delay that most likely now until (week-3); (the 2nd week of June). So on again off again warming and cooling along with periods of wind look likely to continue through or into the 1st week of June.
Have a great Memorial Day Holiday……If you get the chance, get over the Sierra Crest into the Yosemite Valley, as I hear it is quite beautiful now.
Dr Howard and the Dweebs……………………:-)
After mulling over the guidance this morning it is apparent that the current Trof moving into the pacific northwest initiating another period of snow for the Cascades and wind and cooling for our high country may be the last of the colder half of the year. Lots of folks around town have periodically asked if winter is over and my reply has been no, not yet. However today, after seeing the trend from the Climate Forecast System for the jump in heat for California, which is contrary to earlier forecasts of trofing through mid June. The trend now is away from additional troughing in June as a strong upper Subtropical high sets up over the far west and California during the Weeks 3 and 4.
This means that this current cool down along with subfreezing temps at resort levels may actually be the last of the season, as although we will be cooler the next few days, and seasonal temperature wise into this weekend and next week. Temperatures will climb to above normal later next week and beyond. It is starting to look like and early hot summer for California. And….After two dry years, you know what that means…
The Monsoon Season may get an earlier start, however, high based thunderstorms just need an elevated source for a couple of days to get going.
Mammoth residents should prepare now for the Summer by clearing brush, tree limbs close to roofs and small trees below the canopy to fire safe their homes and yard.
Forecast and Summery:
A strong cold trof now moving into the pacific northwest bringing strong gusty winds to the high country along with a cooling trend. The cooling should bottom out by Thursday with highs in the low 50s and lows in the 20s. In that there is a strong blocking high over the Midwest, the trof will be slow to move out of the northern Great Basin. So breezy weather is likely to continue into Thursday. Expect height rises over the weekend with temps returning to near normal then. No precipitation is expected this weekend. High temps will be seasonally in the low 60s and lows in the low 30s.
Although the GFS has another system over the far west next week bringing another round of cooling, the ECMWF is warmer and drier. The thought is that no matter whether we get another round of cooling and wind or not next week, the Hemispheric Pattern shift is such that by the following weekend, we get into a pattern of above normal temps which will likely increase into week 3.
Dr Howard and the Dweebs………………………:-)
PS. Congratulation’s to my Son Clifford for Graduating last Saturday from
USC’s KECK School of Medicine with the degree of MD.
Way to go Cliff!!!!
Major Change in Hemisipheric Pattern to effect Eastern California with Cooler more Unsettled Weather more on than off through the end of May……However, this weekend looks fair and mild, then warm the beginning of next week….
Wednesday May 15, 2013
Posted at 9:00 am by Howard
Models are trending a bit slower and stronger with the Thursday Trof, now lingering it into Friday. Although yesterdays guidance showed about 8 to 10 degrees of cooling, it now looks more like between 10 to 15 degrees total. With the deeper scenario, heights will be lower and thus along with the stronger breezes Thursday, snow showers will likely develop over Mammoth. Additionally, it may stay showery on and off through Friday night. The weekend looks Fair and warmer with highs back to near 60 Saturday and mid to upper 60s Sunday and Monday.
As indicated yesterday, there is a fundamental change in the Western Hemispheric Pattern Taking place. Whether it is MJO initiated or the fact that the QBO is now stronger in its positive mode. Blocking that has been so strong over Eastern Canada, east to Greenland this past Winter/Spring has totally broken down, with that upper height anomaly NNE on the other side of the NP. The main PV is now located north of the Bering Sea. A high latitude blocking High is setting up over west-central Canada. That combined with changes over the western Pacific, possibly initiated by the MJO, teleconnects to an incipient long wave trof that may prove to be stronger and more persistent over time. Once set up….The Climate Forecast System Vs.2 does not break down the west coast long wave until the first week of June. Sensibly, we will begin to experience unsettled weather tomorrow into Friday with a break over the weekend into early next week. That may prove out to be the last of the warm weather as the long wave begins to extend SSW along the California coast the middle of next week into that following weekend.
Memorial Weekend weather may be much cooler than normal with snow showers possible or ????
Next update Monday or Tuesday as the Dweebs will be traveling again…….:-)
Temperatures to trend slowly toward more seasonal norms the next week to 10 days as a series of weak trofs effect the central west coast
Monday May 13, 2013
Posted at 3:07 pm by Howard
Tuesday Morning Update:
Latest guidance points to a Vort max that has recently moved on shore just south of Monterrey Bay at 15Z. You can see the dark area of that Vort center plainly on shore in the water vapor loop. Although the timing of the dynamic forcing will not be perfect as the dynamic lift for the Sierra will come too early for the diurnal heating…..there will nevertheless be some buildups and some Thunder/RWs over Eastern Ca. No cooling is expected now from this system. A stronger trof will move into our region Thursday, bringing about 8 degrees of cooling along with gusty SW breezes during the PM hours. A few showers are possible Thursday Evening.
A NW flow aloft with higher heights at 500MB will finish off the weekend promoting high temps back into the upper 60s and low 70s Sunday and Monday. The next note worthy weather system will develop the 2nd half of next week. It is a colder trof bringing the chance of showers. Stay tuned on that one. A long wave trof may develop and hang around for quite a while there after.
Its springtime in the Sierra!….and the Maps show it!
If you think that it has been warmer then normal the past several days…you are correct. Seasonal highs at the 8000 foot level should be more in the low 60s this time of the year while lows are expected in the low 30s. The past week, mammoth experienced highs in the low 70s and lows in the 40s. With the positive height anomaly shifting to the east, a slow cool down will take place the next few days along with an increase of afternoon breeze. However, with all said, highs will still average some 5 to 8 degrees above normal until stronger trofing develops later next week. Daytime Highs may then return to the low 60s or possibly lower.
North American height anomalies in the 6 to 10 day outlook show positive height anomalies over North Central Canada and Southern Ca with lower heights north of AK and the pacific NW. The polar vortex is set up north of AK. So a split in the westerly’s and a southern branch will develop off the west coast pushing marine air into the coastal areas beginning Thursday. The longer range shows even lower height anomalies later next week. All in all its still spring. The Dweebs would not be surprised to see another dusting over the higher elevations by the following weekend.
Dr Howard and the Dweebs…………………………………..:-)