Another Upper Trof will push into the Pacific NW this weekend bringing some cooling along with stronger Zephier breezes…..Saturday through Monday…..Summertime Monsoon Still Shut Down for the Central Eastern Sierra with signs of a return before the end of the month….
Friday July 15, 2016
Posted at 8:10 am by Howard
Although the Pacific NW upper Trof has slowed some from last weeks forecasts…gradients are still forecast to tighten tonight and Monday. Gusty winds a good bet later tonight and Monday along with some cooler temperatures Monday. Big changes are in store for Eastern CA over the next one to two weeks. The European model has strong retrogression of the long wave features of some 20 degrees of longitude later this upcoming week. That will put the continental subtropical upper high over the top of us for another real heat wave. In fact if the current operation EC model should verify, we may have our 1st 90 degree high this year in Mammoth by the 25th. Of course if the seasonal wind kicks in, that would be a different story with relief via thunderstorms. The model develops a 600DM upper high at 500mb pretty much over the top of us by the 25th. Although a long way off, CPC is in agreement with their new 6 to 10 and 8 to 14 day outlooks. They show very hot temps over the state with the potential of new high temperatures records being broken in their 8 to 14 day outlook..
Further comments Monday AM the 18th;
The reason why we are seeing another bout of heat coming our way is related to the same system that is currently making for quite breezy conditions today. At the moment we have an anomalous upper trof off the coast of the Pacific NW that is associated with a stronger belt of westerlies across the North Pacific this summer. This is due to the fact that the Arctic is actually colder than normal is specific areas this Summer. This makes for a stronger and more persistent belt of westerly along the US Canadian border over the far west and westward over the North Pacific. That same belt of stronger westerlies, “when the dip in the upper jet is off the west coast”, forces the Continental Subtropical High east of its normal position for the Summer. This results in the Summertime monsoon coming out of Mexico further east with very dry conditions over the far western interior as well as very dry breezy weather in the high country. The European Model is becoming more consistent, Run to Run in the retrogression of the long wave features. The European is showing retrogression of about 20 degrees longitude over the next week. So the Dip in the upper jet will occur about 1500 further west by the end of the week. However…here is the interesting point of it all….. the westerlies remain strong to the point that the continental high in order to retrograde has to become stretched out westward underneath the westerlies, instead of being an oval bubble in its retrogression. The up shot is…..That we may not see any moisture backing with its retrogression. If the retrogression occurs like the EC is showing the end of this week and heights at 500MB rise to near 600DM over Central CA…..Bishop could hit 108 to 110 and Mammoth in the low 90s as our air mass would be bone dry and no moisture or occasional dynamics to inhibit the super high temps…..
Monday AM 11:10AM;
New 12Z GFS has similar idea to the ECMWF but with a twist. It develops a weak upper trof over the Northern Great Basin that keeps the Continental Sub Tropical High from becoming too strong like the ECMWF and thus too hot for CA. The GFS version is still a dry pattern through. It will bring hot temps but no records. Then during week 2 or the end of the month….strong SE flow develops in its configuration which allows both Dynamics and Seasonal Wind Moisture to invade CA from the SSE.
Eventually…. a lot of high and mid level moisture moves in to suppress the heat wave a bit. Additionally, pattern generated by the GFS would set up a lot of instability for thunderstorm’s with potential for areas of heavy rain by the end of the month of July. Only time will tell which model has the right idea.
The Dweebs will have a much better handle on the weekend and early next week heat wave by Wednesday or Thursday this week. It is a dry 5 to 7 day outlook. in the meantime
Dr Howard and the Dweebs…………………….:-)
Although there will be little temperature change today over yesterday…Another Upper Trof will push through the pacific NW bringing breezy afternoons and evenings, Saturday though Monday. A cooling trend begins Saturday with high temps from the current mid 80s down to the mid to upper 70 by Sunday into Monday. Nighttime lows will remain cool in the dry air with lows in the 40s this weekend before sunrise. The Hemispheric pattern retrogrades next week with the subtropical continental high moving and spreading west. This will first bring very warm temperatures back into the Mammoth area the second half of next week. Thereafter….As the upper flow backs more from the SSE during the last week of July, Monsoon moisture and dynamics will return, as the season wind brings the chance of summertime showers to the high country again.
Mammoth Lakes Temps:
FRI SAT SUN Mon TUE Wed Thur
SUNNY SUNNY SUNNY SUNNY SUNNY SUNNY SUNNY
84 47/77 48/75 47/76 47/78 48/78 48/77
High Pressure building in over Northern CA and Western NV will begin warming trend through Mid Week with light breezes…Summertime Monsoon shut down untill further notice….
Monday July 11, 2016
Posted at 9:27 am by Howard
The weather pattern over the far west was anything but normal the past few days with 100 MPH winds over the top of Mammoth Mt Sunday AM with a rather chilly Monday morning. There were several reporting RAWS sites with 32 degrees this morning. Crestview…Bridgeport and Ellery Lake. The anomalous weather is due to the combination of an active western pacific with tropical storms amplifying the down stream pattern and a strongly negative WPO teleconnection that is currently off the chart from a standard deviation of normal. It would be very interesting to see this pattern in the Fall (September-October) here in the Eastern Sierra!
Today begins a warm up that will continue into the beginning of the weekend then cooler breezy weather returning by Saturday PM into Sunday. Expect high temps in the low 70s today then low 80s by Mid-Week. Winds will be light.
One of the big factors in the new pattern is that the Continental high is both either weaker and flatter over the desert southwest or displaced well east at times. This is due to the anomalously strong -WPO (Western Pacific Oscillation) and an anomalously strong trof off the coast of the pacific NW. This for the most part, is cheating the Pacific NW of Summer and the Sierra of the Summertime Monsoon. I believe that the MJO is partially responsible for all this, along with an increase of anomalous warm water developing over the tropical western pacific. The strengthening trades and a positive ONI are all working together toward LA Nina…..
Another thought is the very low solar (lack of sunspots) that is coincidently occurring at the same time as the solar cycle races toward the solar minimum. As mentioned in a previous post, The few years leading up to and after the solar minimum seem to be cooler and wetter further south down the west coast. So…. It may be that over the next 5 to 7 years we may have more normal to wet winters than dry ones….
Dr Howard and the Dweebs…………………………:-_)
West Coast Ridge weakening this week leading to more seasonal temps through Thursday…..Strong for July upper trof will move through the pacific NW bringing cooler weather….Gusty Winds and Critical Fire weather Saturday……
Wednesday July 6, 2016
Posted at 5:14 pm by Howard
History in the making….Top of Mammoth Mt gusts to 103MPH this morning at 5:00AM….Still gusting to 98MPH……Chatted with lead forecaster at RENO this AM…..This July trof is the strongest for this time of the year “ever recorded”. Standard deviation from normal is off the chart….
Weather conditions have been spectacular the past couple of days with seasonal temps and light afternoon breezes. Highs have been running in the mid to upper 70s with lows in the upper 40s. This will begin to change Friday as an seasonably cool trof for this time of the year moves into the pacific NW sending high temps in Mammoth down into the upper 60s by Sunday with moderate gusty winds Friday into Saturday. Night time lows will drop into the 30s in the high country, and low to mid 30s in some of the colder locations, If you are planning on back country travel this weekend, plan accordingly.
Ridge top gusts are expected to be in the 50-70 MPH range with the chilly temps Saturday night. Winds in town could gust 30 to 40mph Saturday morning through Saturday. This is a dry pattern so no precipitation is expected in Mono County. The upper trof is progressive and so ridging will build back in, with seasonal temps returning by Wednesday.
As mentioned in the last discussion, this pattern will make it very difficult for any monsoon moisture or dynamics to move up from the south or southeast. It may be that it will continue drier then normal until the period between the 17th and 20th when monsoon moisture and dynamics make a return.
FIRE WEATHER WATCH REMAINS IN EFFECT FROM SATURDAY MORNING
THROUGH SATURDAY EVENING FOR GUSTY WINDS AND LOW HUMIDITY FOR
MONO AND EASTERN ALPINE COUNTIES AND MINERAL AND SOUTHERN LYON
* AFFECTED AREA…FIRE ZONE 273 MONO AND EASTERN ALPINE COUNTIES
AND FIRE ZONE 459 MINERAL AND SOUTHERN LYON COUNTIES.
* WINDS SATURDAY…INCREASING WEST 15 TO 25 MPH WITH GUSTS 35 TO
* HUMIDITY SATURDAY…8 TO 15% INCREASING TO AROUND 20% LATER IN
* IMPACTS…THE COMBINATION OF GUSTY WINDS AND LOW HUMIDITY CAN
CAUSE FIRE TO RAPIDLY GROW IN SIZE AND INTENSITY BEFORE FIRST
RESPONDERS CAN CONTAIN THEM.
AVOID OUTDOOR ACTIVITIES THAT CAN CAUSE A SPARK NEAR DRY
VEGETATION… SUCH AS YARD WORK… TARGET SHOOTING… OR
CAMPFIRES. FOLLOW LOCAL FIRE RESTRICTIONS. CHECK WEATHER.GOV/RENO