(1/5) Heavy rain, strong winds, & high elevation snow this week. While there are still some details with timing that need to be worked out, confidence is growing the heaviest, most widespread precipitation will occur late Sun into Mon. Additional precipitation expected Tue-Fri. (2/5) Snow levels are expected to be 7000-8000 ft during the bulk of the precipitation Sun and Mon before falling to around 5500 ft Tue. That means below 7000 ft, rain will be the main hazard. Most of the precipitation will accumulate on the western San Bernardino mtns.

Morning #HurricaneHilary 🧵

#Hilary continues its trek northward this morning as rain continues to overspread SoCal. Regardless of its eventual status as a hurricane or tropical storm, the forecasts for heavy rain and catastrophic flooding remain UNCHANGED. #CAwx

Is it confusing/tricky to associate a "weakening storm" with a consistent catastrophic flooding threat? Absolutely! But these categories are based on wind alone, and while there will still be wind impacts, heavy rain and flooding remain by far and away the biggest threat. #CAwx

(1/4) Here is our preliminary thoughts on the timing and intensity of the precipitation for the rest of this week. Off-and-on rain showers will be possible from late tonight through Thursday with light accumulations. Heavier and more widespread precip develops Thursday afternoon. (2/4) For Thursday through Saturday, an atmospheric river takes aim at Southern California, leading to widespread moderate to heavy rain, with the heaviest expected to occur on Friday. Heavy mountain snow will also be possible Thu-Sat, generally above 5000 feet.

(1/4) ⚠️ HAZARDOUS TRAVEL IN THE MOUNTAINS THIS WEEK ⚠️ winds will rapidly increase this evening and peak overnight in the mountains. Snow levels will crash tomorrow morning, potentially as low as 2000 feet. READ THE WHOLE TWEET THREAD BELOW: (2/4) PLEASE NOTE: The snow accumulation graphic is only for snow accumulations through Thursday morning. ADDITIONAL HEAVY SNOW, ON THE ORDER OF SEVERAL FEET OF SNOW, WILL BE POSSIBLE THURSDAY NIGHT THROUGH SATURDAY.

(1/3) In preparation for the hazardous conditions developing this week, we will be sharing safety information for the multiple hazards we are expecting. Up first, winter weather (snow) safety! ❄️☃️ (2/3) There is a Winter Storm Warning in effect from tonight through Saturday for the San Bernardino/ Riverside/ San Diego County Mountains, Santa Ana Mountains. Expect damaging winds and extremely heavy snowfall.

(1/8) We have quite the storm this week. We will lay out the impacts in this order:
1. Rain and Flooding
2. Wind
3. Snow
4. Hazardous Marine Conditions
Please read through the full thread & know that we are always looking at/updating the forecast as we get new information.
#CAwx (2/8) Scattered showers will be possible as early as Mon morning across northern areas & will spread to the southeast by Mon night. The heaviest/most widespread rain will occur Tue morning/afternoon, and flooding will be possible. T-storms will also be possible during this time.

(1/5) After a quiet weekend weather-wise, the next in a series of storm systems will begin to impact SoCal next week. Widespread moderate to heavy rain (with a slight chance of t-storms) and very strong winds can be anticipated. The heaviest precip is expected across SBCo Mtns. (2/5) Rain may develop as early as Mon morning across Orange/San Bernardino Counties, with light rain spreading southeastward through the day. However, an increase in activity is expected through Monday night, with with heaviest and most widespread rain occurring on Tuesday.

(1/4) The first week of 2023 looks quite stormy! After rain diminishes tonight, the next chance for widespread rain looks to develop tomorrow night-Tue morning. The rain isn't expected to be as heavy as last night, but widespread accumulations are expected. (2/4) Rain will increase from northwest to southeast Monday night. Preliminary rain totals are as follows:
Coast: 0.50-0.75"
Valleys: 0.40-0.75"
Mountains: 0.50-1.00"
Deserts: 0.01-0.20"

2023 is bringing us an #AtmosphericRiver for its arrival! Because 280 characters is never enough to summarize these, here's another 🧵of our updates and what we're expecting! #CAwx (1/6) We've hoisted a Flood Watch for tomorrow evening given the potential for widespread rainfall everywhere from the mountains westward. Use extra caution if you're out and about! Travel will be dangerous given rain, lots of folks on the road, and... other reasons🥴#IYKYK #CAwx (2/6)