September to end on a very warm note with October hot on it heals!….Models now back peddeling on cold system for next weekend……WX just returning to Climo….
Saturday September 29, 2012
Posted at 8:29 am by Howard
Quick Sun AM Update:
Gorgeous Days ahead, with the heat peaking Monday into Tuesday with highs in the upper 70s! Bishop up to 93 degrees Monday/Tuesday but no records. The records for Bishop set back in the 4 day heat wave of 1980 was 95,97,95, 96 beginning September 30th and the following days into October.
Pattern highlighted by strengthening upper high over Ca as upper low retrogrades further off shore then deepens next week. Pattern becomes progressive after the following weekend. Eventually the offer shore upper low will come into California “around” the middle of the following week. When it does, there could be that dusting that folks are looking for with the coolest days since last Spring. That will be around the 7th-8th of October. This mornings operational run of the 12z GFS suggests another small closed low splitting off from the westerlies and taking about the same route into Ca around the 15th or so. Overall…..temperatures are expected to end up above normal for the month of Oct. Cool inside slider to return temps to near seasonl value by weeks end…then further cooling expected when the upper closed low comes in abouth the middle of that week. (7th/8th)
Yes…it is early Fall and mother nature has the right this time of the year to change her mind frequently…..
An anomalous strong upper high will build over the Ca and bring some of the warmest temps for early October. Highs over Mammoth may reach mid to possibly upper 70s while bishop heads for the low to mid 90s. If that ain’t Summer weather what is? Meanwhile, as the upper ridge builds, cool air will radiate out in the longer nights and provide freezing temps to the lower valleys of Mono County each night through Tuesday AM. Areas like Crestview will go below 30F at night.
Retrogression of the upper high and the configuration of a developing REX block off shore will keep the strong short waves from digging too far south and west. Instead, it is scenario 2 from the last post where the system will dive into the Northern Rockies and bring some wind and cooling for the high country. The Northern Rockies will receive their first winter like weather. Precipitation over Northern Ca if any, would be scant.
Upshot will be a return to Climo with highs cooling to the low to mid 60s by the following Sunday. Currently…the new 9/29/12-12z operational run of the GFS is consistent with last nights run in progressing the block to the west coast for warmer temps. Now with all that said, that upper level mid latitude low portion of the block has to come in sometime. When it does, there will probably be clouds, showers and further cooling. That should hold off now until early the 2nd week of October.
Like March and April, longer range models are not nearly as accurate as they are as compared to the November through February time frame.
The Winter forecast is still a long way off from being understood in my opinion as lots of things are changing. In the meantime, we do not get Summers and early Falls like this very often….so enjoy it while it lasts!!
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.