More frost and freezing conditions overnight with weekend rain in sight

Posted at 12:59 PM, Jan 02, 2019
and last updated 2019-01-02 20:45:38-05

High pressure to the east will continue to guide offshore winds in the night and morning hours with mostly clear skies setting the stage for another very cold night ahead.

People should expect more lows in the low to mid 20s in SLO county’s interior valleys with low 30s in the coastal valleys during the overnight hours tonight into Thursday morning.  This is similar to the lows we saw this morning.

Lows this morning

Some locations will not get advisories since freeze and frost conditions have already occurred, however this doesn’t mean that the conditions will not exist. In fact it is likely much of the area will see temperatures at or below freezing again tonight. There is an advisory for the SB county coastal areas for a freeze.

Freeze Warning Map

There will be some improvement on temps Friday with increasing clouds, and warmer overnight lows. This will be due to an approaching low pressure system poised to deliver rain to the area on Saturday.

The south winds are the key to the upcoming system. Currently the air is bone dry so the next system will have to prime the area with moisture. Models appear to be picking up on this today with a reduction of storm estimated rainfall to the .5-1.5″ range (yesterday models liked 1-2″ of rain). For a change the mid-range models are actually in alignment. The storm system arrives Saturday and looks to linger into early Sunday before moving off. South winds 15-30mph will peak Saturday with the low’s arrival.

EURO model of weekend rain potential

Monday and Tuesday look quiet but another rain is possible on Wednesday in a pattern that looks to get more active.