TODAY’S LATEST SATELLITE PICTURES:
TODAY’S WEATHER DISCUSSION AND FORECAST:
Today’s Forecast for Crestline, Lake Arrowhead and the San Bernardino Mountains.
Today we will start the day with high based clouds at or about the 20-30k’ level. We continue to have a weak upper level North East flow across the area due to a 4mb pressure gradient from Tonopah to San Diego. At the lower levels a South West flow is present with some low clouds and fog along the Coastal areas. Temperatures will remain about the same through the week with some slight cooling. Daytime highs will run in the upper 50s to mid 60s with overnight lows from the mid 30s to low 40s below the 6000′ level. Above that elevation, temps will be in the mid to upper 50s during the day with overnight lows from the mid 20s to low 30s.
This week there is a lot of activity off the West Coast. We will start the week under a ridge of High pressure. then a cut off Low will develop to our West for Tuesday. That will push high clouds and possibly some ridge fog on the south facing slopes for Wednesday/Thursday. There will be a 10% chance for some localized drizzle and or a quick sprinkle. As that system passes to our North, another cut off Low will develop bringing more low clouds and possible fog to the area for Friday. Again, a chance for a shower and or drizzle to the south facing slopes locally. At this time, Friday looks like the best chance to see some precipitation locally for the next seven day period. I would put a 25% chance for a shower for Friday as it looks today. These will be warm systems from over the Ocean to our West, so the snow or freezing levels will remain high through the week. So, there are three of these systems that will affect our weather over the week ahead. All of these systems are Cut Off Lows and are hard to be sure what they will actually do. This is how it looks this morning. A Cut Off Low is an area of low pressure that has separated from the guidance of the Jet stream temporarily. They tend to form off of the West Coast, bobble around for a couple days or so, then reconnect with the Jet Stream and move on. So forecasting where they will go is based on experience, knowledge, and model forecast trends combined. I will be taking a day off tomorrow so I will say to everyone now, have Happy New Year, and may 2018 be a great year for all!! Thank you for your support over the past years. I’ll be back with the latest forecast Tuesday the 2nd of January.
Have a good day and thanks for joining me @ lakegregoryweather.com RC