Full On Summer Weather Expected this Upcoming Week with High Temps in the Upper 80s by Wednesday…Thunderstorms Possible with Chance of Additional Moisture Friday for Wetter Storms….Then Drying Trend Saturday into Monday…With Season Temps by Weeks End into the Next Week
Sunday July 8, 2012
Posted at 10:20 am by Howard
Quick Thursday Update:
Dew-points are rising with the temperature this morning an indication of warm moist air advection…..Combined with the daytime heating will allow thunderstorms to form with better areal coverage then yesterday. Still main focusing is expected along with a lot more moisture Friday.
Temps will be a little cooler today and cooler Friday with the possibility of wetter storms….
Bishop tied record high yesterday of 106 Bishop will be cooler today with the possibility of high based dry thunderstorms
Quick Wednesday Update:
1. Today appears to be the warmest day with new 12z WFR showing 500-1000mb thickness isohyet of 594dm protruding west into Eastern Ca.
So with consideration to both the time of year, current blocked moisture pattern to the south due to the East-West upper ridge axis, upper 80s looks likely for Mammoth at 8000 feet. 88 degree is the average highest Mammoth Lakes temperature normally during the Summer. So today may be the warmest day of the year. By Thursday, the upper high shifts a bit east opening the door to monsoon moisture. It will be a race during the day for an equally warm day before the skies cloud up. 500-1000mb Thicknesses do not get as high on Thursday for Mammoth so again it may not be as warm. Did not check 700mb temps though. By Friday the ridge weakens a bit and shifts well into Utah. At the same time a moist SSE flow is well established and most important of all, a vort center at 500mb shifts from south to north over the Sierra. Friday and Friday night look like the best chances for Thunderstorms…. 700Rh is in the 60% range from the new 12z Wednesday Run. It will be humid in the Owens Valley. Expect dew points up into the 50s in Bishop Friday.
Then flow backs to the SW Saturday for a slow drying trend with cooler more seasonal weather on the way by the end of the weekend into the next week. Highs back into the upper 70 with low in the 40s Sunday into Wednesday.
Monday AM Update:
No real changes the first half of this week. Upper high slowly building west will continue the warm up through Wednesday. Upper levels too warm for any significant TSRWs activity today and most likely Tuesday….although a few may pop. If they do….they will be high based and have little rain. As we get toward the back side of the warm up about Wednesday/Thursday, some increase in activity will occur Wednesday. Although Wednesdays highs will be warmer in many locations, in upper elevations of the Sierra, it may be a little cooler, as cloudiness will build a bit quicker in the late Am hours. Some Thunder possible Wednesday, before most models bring in more SE flow Thursday into the weekend with areal coverage increasing for the high country Thursday through Saturday. At this time there is no clear picture on whare the main focus will be or what mechanism will trigger the best activity. However, more instability is expected going into the Weekend as a weak upper Trof interacts with hot and potentially moist air mass. Moisture advection may add to the mix for the possibility of wetter storms Friday-Saturday. For Mammoth, High temps will be in the 80s this week with lows mostly in the 50s then 40s late in the week.
The transition to Hot Summer Weather is now complete as compared to 7 to 10 days ago with that chilly negative height anomaly off the coast of the pacific NW. Although there may be weak trofs now and then effecting the pacific northwest and ushering in a dry SW flow aloft, temperatures will be normal to above for sometime to come.
At the moment we have the core of heat building over the great basin. This is expected to strengthen over the next few days. The Thermal trof will apparently jump back and forth between the central valley and western NV and so there will be periods of Zephyr winds that will help deal with the high elevation heat in the late afternoon and early evenings. There although there will be warming in the upper levels…there will still be enough lift from instability at the surface to pop a few high based thunderstorms until about Wednesday or Thursday when instability increases aloft as some cooling begins in the upper levels. Any added moisture monsoon related would be enough to get the ball rolling to increase areal coverage of TSRWs. Stay tuned on that…..
High temps will reach the upper 80s in Mammoth by Wednesday with the peak of the High pressure system. There after, some hint of SSE flow may increase moisture with Thunder Thursday into Friday. High temps will then get cooler from cloud cover if that happens. However, it will remain very hot over the Owens Valley until the end of the week…..Bishop temp forecast is 105 Tuesday and Wednesday. Some Thunder there after is possible Thursday and Friday for the Owens Valley as well as conditions become potentially more humid with any seasonal wind.
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.