9:30 pm – The #1 lane of Highway One, just north of Fremont and south of Casa Verde in Monterey is flooded. SLO Co has declared emergency status for all emergency personnel due to flooding, and the worst is supposed to hit here between midnight and dawn.
6:30 pm – Uh oh. There is a big cell taking a bead on the Santa Cruz Mtns. and they do not need that!
6:00 pm – sounds like the distant rumbling of thunder … but I could be mistaken. Winds up, sporadic rain.
5:00 pm – here is the big picture, sent to me by Dave Allen. Note Dave’s comments under the satellite photo:
We have a HUGE counterclockwise rotation, taking up the entire Pacific. The NWS in Hawaii calls it an “Omega Block”, which means a vertical rotation of air mass. In this case, it is rotating upward, in a mega-cyclonic fashion, creating unstable weather across the vast reaches of this hemisphere. In Hawaii, they are getting heavy showers and t-storms. The unstable stuff in Hawaii then gets rotated over to us for our share of the same. To add to the morass, you can see TWO double-decked cyclones embedded within this big omega block, right over the West Coast. The lower cyclone is centered over central and southern Cali, and the upper one is spinning over the Oregon/Washington coast. And of course, this atmospheric transmission of gears is driving that “Pineapple Express” across the base our state, into Arizona. For now, our concern is the lower cyclone of the double-decker. It is in overdrive from the omega block, and has a lot of momentum. With a quick surf-check a few minutes ago, we could see the black wall on the horizon, and the southerly wind-line 1/2 mile offshore. Batten down the hatches…here it comes!
3:30 pm – The temperature has really dropped this afternoon, so I wouldn’t be surprised if there was a bit of snow by morning, even if not mentioned by NOAA.
NOAA predicts: “AS OF 3:00 PM PST TUESDAY…RADAR RETURNS HAVE BEEN VERY SPOTTY MOST OF THE DAY TODAY ALTHOUGH THE PAST SCANS HAVE DEFINITELY BEEN TRENDING UPWARD AS THE NEXT ROUND OF RAIN HEADS TO OUR AREA. SATELLITE LOOP CLEARLY SHOWS A LONGWAVE TROF MOVING IN FROM THE COAST WITH A LOW HEADING TOWARD THE WASHINGTON/OREGON BORDER. WITH SOME INSTABILITY…WIDESPREAD RAINFALL IS FORECAST FOR TONIGHT.THE MAIN PRECIPITATION WILL START [in] THE MONTEREY BAY REGION EARLY IN THE MORNING…THIS SHOULD BE A SHORT-LIVED EVENT SO RAINFALL TOTALS SHOULD JUST BE BETWEEN 1/3-2/3″ FOR URBAN LOCATIONS WITH 1-2” FOR HIGHER ELEVATION SPOTS. ANY OF THE STRONGER CELLS COULD PRODUCE BRIEF HEAVY RAIN…SMALL HAIL AND GUSTY WINDS. IN ADDITION…925 MB SPEEDS ARE EXPECTED TO BE 30-40 KT WITH THE MAIN ENERGY FOCUSED ALONG THE COAST SO ANY SOUTHERLY EXPOSED PLACES (ESPECIALLY COASTAL RIDGE TOPS) COULD SEEN WINDY CONDITIONS TONIGHT.
ON CHRISTMAS DAY (SATURDAY) ANOTHER ROUND OF RAIN WILL SWEEP THROUGH THE CWA. AT THIS TIME…THIS APPEARS TO HAVE THE POTENTIAL TO BE EVEN STRONGER THAN THE STORM TONIGHT WITH BOTH THE QPF AMOUNTS ALONG WITH WINDS. 925 MB SPEEDS WILL HIT THE 40-50 KT RANGE IN SPOTS WHILE PW VALUES OF NEARLY 1 INCH WILL COMBINE WITH ISENTROPIC FLOW OF 50- 60 KT. THIS IS STILL A FEW DAYS OFF SO BOTH TIMING AND INTENSITY COULD CHANGE…HOWEVER IT HAS BEEN DEPICTED BY MULTIPLE MODEL RUNS NOW SO CONFIDENCE IS INCREASING. AN SPECIAL WEATHER STATEMENT HAS BEEN ISSUED (SFOSPSMTR) IN PARTICULAR TO NOTIFY PERSONS PLANNING ON TRAVELING DURING THE HOLIDAY WEEKEND. WOULD DEFINITELY APPRECIATE IF THE LOCAL MEDIA WOULD ALSO HIGHLIGHT THIS TO HELP PEOPLE WITH THEIR TRAVEL PLANS.:
1 pm – Water Vapor Satellite Map. Thanks, Dave.
The NEXRAD is showing only very scattered showers at the moment, no big bands. But those scattered showers are over my mountain.
10 am – Happy Solstice! Days will start lengthening again, and a new year is born. I am a wee bit behind this morning, due to difficulties getting the gennie started. I’ll catch up with my reports in no time.
WINTER BEGINS AT 3:38 PM PST TUESDAY…DECEMBER 21.
CHP reports no problems on Highway One at this hour, but more rain coming, so be careful.
NOAA writes: “AS OF 9:00 AM PST TUESDAY…MAIN CONCERN FOR THE DAY TODAY IS FOR THE NEXT 24 HOURS AS AN APPROACHING LONGWAVE TROF WILL SPREAD ANOTHER ROUND OF RAINFALL ACROSS THE CWA. AHEAD OF THIS… PLENTY OF MOISTURE AND A POOL OF NEGATIVE LIFTED VALUES WILL HELP TO KEEP SHOWERS AND THUNDERSTORMS GOING TODAY ALTHOUGH COVERAGE WILL BE SCATTERED AT BEST. CURRENT LIGHTNING DETECTION IMAGE SHOWS MULTIPLE STRIKES NEAR AND IN OUR NORTHERN WATERS SO WILL BE KEEPING A VERY CLOSE EYE ON CELLS AS THEY APPROACH THE COAST. WIDESPREAD RAIN WILL RETURN THIS EVENING AND CONTINUE THROUGH THE OVERNIGHT HOURS AS THE TROF MOVES TO THE COAST. MODEL TIMING CONTINUES TO SHOW THE MOST LIKELY TIME FOR RAINFALL FROM AROUND MIDNIGHT THROUGH MID-MORNING. AFTER THAT PRECIPITATION SHOULD RAPIDLY DECREASE AND EVENTUALLY LEAD TO TWO (THURSDAY AND FRIDAY) QUIET DAYS.