Discussion on California wild weather

[WXBUFFJIM]

Good morning. A busy day weatherwise today as we track a very strong Pacific storm plow into California and Oregon. This classic low pressure system has strengthened this morning just off the northern California coast to 978 millibars. As seen on satellite this morning, this potent storm has a counterclockwise rotation with a very strong low level jet of 60-70 mph at 3000 feet out ahead of this system. This strong low level jet is feeding additional moisture into this system because it's coming from Hawaii straight into the golden state. This type of connection is known as a subtropical connection or the pineapple express. Combine that moisture feed to the fact that this precipitation is running into the foothills of mountainous terrain presents huge problems because the wind flow is expected to be perpendicular to the foothills. This means maximum orographic lift will occur in California enhancing precipitation totals to dangerous levels. This will also be a prolonged storm system because of that subtropical connection feed or pineapple express. That will mean major flooding rains likely for the valleys and especially the burned areas, and a paralyzing snowstorm for the mountains. As a result, the main effects from this storm will be huge seas with up to 50 foot rogue waves possible, coastal flooding on the California coast, strong winds with gusts over 60 mph along the coast, heavy rains in the lower elevations and a tremendous amount of snow in the higher elevations. The following is a breakdown region by region as to the expectations from this major storm system across the golden state!!!

Starting in the coastal areas where numerous advisories are in effect today through Thursday. From Point St George, California to Cape Mendocino, California and out 20-60 nautical miles, a storm warning is in effect this morning and a heavy surf advisory is in effect today through Thursday night. Expect sustained winds off the northern California coast of 35-50 mph with gusts to 65 mph. High wind warnings are in effect for the coastal communities of Crescent City and Eureka, California. This means expect sustained winds of 25-45 mph with gusts over 65 mph along the beaches and higher elevations also. Seas are expected to increase to over 30 feet later today through Thursday along the northern California coast.

Further south, winds and seas will increase rapidly today and tonight across central California including San Francisco and Monterrey Bay points south into southern California. Gale warnings are in effect for the entire central California coast today through Wednesday. This includes the San Francisco and Monterrey Bay areas points southward through southern California. Coastal flooding is also a possibility as well, thus a coastal flood watch is in effect for the centraln and southern California coast later Wednesday into Thursday. Breaking it down by region starting with northern California, expect winds to increase to 40-50 mph sustained with gusts over 65 mph today. Seas are expected to increase to 25 feet today. However by tonight and Thursday, winds will gradually subside. However combined seas with the wind and high swell is expected to be 25-40 feet with rogue waves possibly reaching an amazing 50 FEET just offshore from the north central California coast. As a result of this, the coastal flood threat will actually be highest Wednesday night into Thursday for the north central California coast. In addition to that, there are high wind warnings in effect for San Francisco for today where wind gusts to 65 mph are posible in higher elevations and along the coastal zone. Across the bay into Oakland and Sacramento, a wind advisory is in effect for today where winds could gust 40-50 mph.

Further south into southern California, the danger is not over as coastal flood watches are up Wednesday night through Thursday for the San Diego beaches while gale warnings stretch all the way down the southern California coast to Long Beach for this evening. South of Long Beach, small craft advisories will be hoisted for tonight into Thursday. However gale force gusts could be felt all the way down to the US/Mexican border along the coast including in San Diego. Seas could be up to 20-25 feet along the southern California coast before we're all said and done with this.

In addition to the coastal impact, there is huge impacts expected courtesy of precipitation and heavy precipitation as well. A flood watch is up for today and Thursday for the central Valley of California including the Sacrmento, and San Joaquin Valley, and surrounding foothills including Lake Counties. Rainfall amounts will range from 2-3 inches in the valley locations to 2-4 inches in the foothills and surrounding Lake County. There could be local areas in central California that see close to 6" of rain with this before w're all said and done. As a result of all of this, expect significant rises of creeks, streams, and small rivers and unfortunately more rain is expected later Thursday into early Friday in this same area as storm system after storm system will combine with a subtropical feed of moisture. Meanwhile in the higher elevations of the Sierra above 5000 feet, expect 2-3 feet of snow today and 1-2 feet on top of that on Thursday. 3-5 feet of snow is likely in the Sierra's above 5000 feet. In the Mount Shasta area above 4000 feet, 2-3 feet of snow is likely to fall between now and Thursday. More snow is expected beyond this time period.

Further south into southern California, flood watches are up for Los Angeles and San Diego including in the burned areas of Simi Valley, the San Bernardino Mountains, and the San Diego Mountains. Burned ares will be most suspectible to dangerous flooding and potentially deadly rockslides and mudslides later today through Thursday. Rainfall total of 2-4 inches is expected for Los Angeles and San Diego with 4-8 inches possible in the burned areas and in orographically favored zones. This will only worsen the flooding and mudslides as all we need is 1/2 inch an hour to flood many areas, especially the burned areas. Unfortunately we may end up with 1-2 inches an hour with this storm system tonight. While we have a deficit in Los Angeles and San Diego, we don't need rain to happen all at once across southern California. In addition to heavy rains, expect heavy mountain snows initially above 7000 feet later this evening, and 4000 feet by later Thursday. Up to 2 feet of snow is possible above 7000 feet in southern California. This includes the LA and Ventura County Mountains. Also Wind gusts of 60-75 mph are possible in the higher mountain peaks of southern California including in the Grapevine north of Los Angeles.

This is a dangerous storm system that should be taken seriously. Prepare to lose power and face the potential of property damage with this storm system in California. Travel is not advisable, especially near flood prone areas, near the coast, and also in ski resort locations. In the case of flood prone areas, if you run into water covered roads, turn around and find another route. Turn around and don't drown. Along the coast, very high surf and coastal flooding could damage coastal property and make travel along the coastal roads impossible. In the mountains, heavy snows and blizzard conditions could potentially shut roads such as route 50 and I 80 in the Sierra over the next day or two. Snow chains are a must if you absolutely have to travel in the Sierra. However the best option is don't travel at all through the Sierra and in the higher elevated areas of I 5 near Mount Shasta so that you can avoid being stranded in this stuff!!! This is a dangerous storm system and more updates will be issued throughout the day today.

Jim