Thread by @805Weather

After about a three week lull for California, a renewed East Asian Jet extension is once again upon the Pacific Southwest’s doorstep just like the latter half of December however this time a more robust forcing from the El Niño could prolong the eventual pattern ahead... #CAwx

The door is finally opening for this El Niño to truly make a show across the North Pacific as @webberweather shows here in his threads from earlier today. (Second thread)

Since Nov our wax/wane of dry & wet periods have been mostly due to destructive interference from the MJO & a +IOD lasting into Christmas but has now long collapsed & the MJO may be yet again moving into phases 5-7 constructively interfering with/ El Niño. #CAwx

In the above graphics I’ve attached to the previous post displaying 500z height anomalies, notice the fine line between baroclinic/barotropic periods in the mid-latitude Northeast Pacific illustrating since late November this pattern within all major modeling ensembles suites.

Going forward & building upon what I’ve posted here previously regarding these swings from barotropic (blocking periods) to baroclinic (troughing) zones, this particular baroclinic zone & jet extension should finish off by Thurs this week. The following Tues, rinse & repeat.

With all this being said going into February. This El Niño’s display when coinciding with forcing on the EA Jet reminds me of trying to get an old Flip Top lighter you know still has fuel & wick left in it. Finally after a few tries… 💥. Late-Jan thru Feb is that 💥! #CAwx

@threadreaderapp unroll please :).

Meanwhile… Here on the Southern California bight. #CAwx

Got the show on the road pretty quickly with this last system of the bunch, but not too shabby given some shadowing here. Raw QPE for the last 24 hours across the state & second graphic is raw QPE for the last 5 days. #CAwx

So that time has come. I’ll be focusing tomorrow night more heavily on the incoming storm systems & what is in store for the Ventura/Santa Barbara County-stretch of the Transverse Ranges & coastal valleys especially with the latest modeling trends ⬆️📈 for storm #2. #CAwx

Just have a look at the 50 member EPS ensemble which has held to the higher trends for the upcoming week KSBA
->KCMA ->KBUR ->KLAX which @Weather_West has been heavily noting. Mostly, just a handful of members are on the lower end QPF – but even those members are quite wet. #CAwx

My updates begin picking up from now into later this evening including a more in-depth discussion of how we got to this pattern, thermodynamics & probabilistic outlooks etc. what still lies ahead for this weekend following storm #1 now making its way down the state tonight. #CAwx

Returning to this post above to show the various global modeling ensemble track records in the middle latitudes for 500z height anomalies between 35°N-55°N & where we are now as El Niño has fully fledged into the New Year… #CAwx

ICON model joins the party tonight… FWIW, the model only runs out to 180 hours. Tonight’s 00z initialization leans further into the other global deterministic models & more notably supports the high-end 90th percentile QPFs global modeling ensembles have been holding onto. #CAwx

Storm system #1 currently over-sweeping the state & now impacting Central & Southern California coasts. Storm system #2 making a prestigious entrance into the middle-latitude central North Pacific with an organizing surface low north of Hawaii & is the one to watch… #CAwx

The wording of the short-term outlook in the latest Area Forecast Discussion from @NWSLosAngeles is foreboding for the next storm currently taking shape north of Hawaii. #CAwx #AtmosphericRiver #SoCalWx

@NWSLosAngeles Following a healthy recharge from storm system #1 streamflow outlooks are getting colorful across Ventura & northwest LA counties as storm system #2 starts to work into the 3-5 day forecast illustrating the rising odds for hydrological impacts still to come next week. #CAwx

@NWSLosAngeles @Weather_West @NWSCNRFC Recharged for the upcoming wild start to the work week. #CAwx #SoCalFloods #LArain #CAFlashFloods #AtmosphericRiver