Dense Fog and Severe Weather Update: Jan 1, 2023

Good evening Tangi,

Happy New Year! 2023 will start out active weather-wise.

Click HERE, HERE, and HERE for an update concerning the dense fog hazard again tonight in addition to the severe weather threat on Tuesday, January 3rd.

Changes from Previous Update:

• The threat of severe weather and heavy rainfall has not changed much from yesterday's forecast.
• Additional timing and impact details of the severe threat have been provided.
• Added dense fog impacts.

Overview:
WHAT: DENSE FOG; MARGINAL RISK and SLIGHT RISK of Severe Weather; MARGINAL RISK of Flash Flooding

WHEN: Dense fog today through 9-10 AM inland and midday along the coast; redeveloping tonight through Monday morning. Severe weather and heavy rainfall threat will be from early Tuesday morning through Tuesday night but the greatest risk is expected from late morning through sunset Tuesday.

WHERE: All of the area for fog. Same for severe weather but the greatest risk will be along and north of I-12.

CONFIDENCE: High confidence for fog today (It's already occurring early this morning!). Confidence in the redevelopment of dense fog tonight is also high but there is uncertainty if the dense fog will be quite as intense and widespread as it was last night. There is low confidence for severe weather at this point as there is still a good amount of uncertainty regarding the details given this event is still 2-3 days out.

Impacts:
The main impacts from the dense fog will be:
Poor visibility:

• Near-zero visibility will make travel extremely hazardous
• Numerous accidents and travel restrictions (e.g., bridge closures) from the dense fog will lengthen commute times

The main thunderstorm threats will be:
Damaging Winds:

• Wind gusts greater than 60 mph will be possible
• Trees and powerlines could be damaged and lead to isolated/scattered power outages

Large Hail:

• Large hail 1 inch in diameter or greater will be possible

Tornadoes:

• A few tornadoes will be possible

Rainfall:

• Locally heavy rainfall could lead to ponding of water in low lying areas and areas of poor drainage.