Archive for April, 2020

April Ends with Record Heat followed by Seasonal Temperatures by Weeks End….Cooler weather will be short lived with a rapid warm up by Mid Week…..

It appears that April will end with a record breaking heat wave for the Sierra. A flat ridge of high pressure aloft gets pumped up over the Golden State with today’s 12z GFS 500mb heights progging a peak of 588 dm by 06z Wednesday, while 500mb-1000mb Thicknesses peak at 572DM Tuesday night and 571DM again Wednesday early PM.  So the warmest day will likely be Wednesday.  Temperatures records for Bishop for the next few days for April are; 27th-90 in 1949; 28th-92, in 2013; 29th -91, in 2013.  It appears that this Wednesday’s Bishop record in is Jeopardy.


Highs in Mammoth will likely reach between 70 and 72 degrees.

For the High Country, as the upper ridge shifts into Nevada Wednesday, strong Zephyr winds 30 to 35 MPH will develop that afternoon into the evening hours. Thursday will begin a cool down in the high country that will extend into Sunday. Thursday afternoons winds will be even stronger with gusts to 40+ mph locally. The Upper Jet is expected to sag south into North Central CA by Sunday Morning. This raises the possibility of some light showers for Mammoth Sunday morning.  More over….the prospects for additional cooling is expected Sunday where high temps are expected to cool to the mid 50s. It will be breezy all weekend…Nighttime temperature’s may return to the upper 20s by Monday AM.

BTW, seasonal highs in Mammoth this week are in the upper 50s,  So as of late, although the highs will reach the low 70s tomorrow and Wednesday, temps will be returning to more seasonal levels which may feel much cooler than what you are going to get used to the next few days.

Longer term:

The trend of temperatures will see-saw next week as heights RAPIDLY increase again over CA by Cinco de Mayo. IT WILL WARM QUICKLY MIDWEEK!   The upper jet retreats north, while the longer range GFS and ECMWF ensembles show the long wave trof retrograding with long wave ridge position holding firm over the far west.  Additionally there are two moderately strong short waves that will be deflected up into the pacific NW both Thursday and Saturday. So the warmth will be accompanied by periods of wind between migrating short waves.


Sensibly, high temps will return above normal next week with highs well into the 60s by mid week and possibly 70 by Sunday the 10th of May.


Dr Howard and the Dweebs…………………………:-)

Wrapping up April Precipitation the next Few Days then serious warm-up 2nd half of the next week with 60s possible by weeks end 26th….

Another 3 to 5 inches of snow fell on Mammoth Mt the past 36 hours.  A few showers are still possible today Saturday as the small storm exits to the east….Sunday looks fair with highs near 50. The next and last upstream system weakens as the upper blocking ridge in the GOA shifts east to the BC, Can coast Sunday. The remains of the short wave comes in Monday into Tuesday AM negative tilt…with showers and possible thunder showers.   The snow level can still give Mammoth Snow Showers.  There after, the upper jet pulls north for an extended period as the long wave Trof sets up north of Kauai and long wave ridging sets up inland over the Far Western States.   With this change, comes much above normal temperatures for California.  This is likely to develop during the 2nd half of next week. In fact, there is even the possibility of near record highs for the Owens Valley the next Sunday or following Monday. (between 85 and 90)  With that said, until a good part of the snow is gone in the high country, it will be difficult to achieve record highs as they most likely occurred during the driest years.  Nevertheless,, 60s is still possible in Mammoth by about the end of next week or early the following week!


Let the serious runoff begin!!


Dr Howard and the Dweebs……………………….:-)

Variable Spring Weather to continue another 6 to 10 days with Sun and Snow…..Tomorrow Wednesday is one of nicest days ahead….

A highly amplified upper ridge continues full latitude into the Gulf of AK this week.  Upper flow today and tomorrow is right out of the north.  Tomorrow, some of that ridge will spread higher heights into California for about 10F degrees of warming while a small upper low comes through the ridge and down the west coast Thursday. Another short wave seems to track in tandem but is not connected as it moves through the Great Basin and Rockies.

The idea is one more of instability for our area Thursday evening and especially Friday, as if this were winter, this little feature would not do much more than create a wind shift. So it is Mid April and CAPE is running higher now. I expect a few isolated showers Thursday late afternoon and especially the evening over Eastern CA as an area of deformation develops over night. On Friday, a zone of east-west deformation develops across South Central Nevada and spreads further west into Eastern CA Friday, triggering snow showers and possible thunder snow.   As the petite upper feature gets closer to the California Coast and comes through Friday, weak upper divergence is possible, to spread showers up the Sierra. The deformation to the SE should keep some action going into Friday night, especially for the Owens Valley.

Snow showers and a few Thunder Storms with some grapple is possible for Eastern CA late Thursday afternoon and evening. Nocturnal storms may continue well into the evening…..Then additional instability expected Friday for greater Arial Coverage.


Saturday looks to be a fair to partly cloudy day with a little warning.  Antecedent moisture will be left behind for Sundays storm.  The Sunday afternoon through mainly Monday system looks more impressive for the Sierra.. Although not a major storm by any means….This undercutting system that moves in Sunday has decent on shore flow Sunday night into early Tuesday. Just a WAG….this might bring some six inches+ of snowfall to the higher elevations by Tuesday. However, this is just based upon pattern recognition….


High temps this week will fluctuate between the mid 50s Wednesday to back down into the 40s this weekend. Lows at night in the 20s for the most part.


This is likely to be more unsettled WX before the end of the month……


Dr Howard and the Dweebs………:-)