Central Coast Braces for Dramatic Warming, Peak Heat Expected Friday
The Central Coast is in for a significant heat event as temperatures climb well above normal today and Friday, peaking tomorrow. While inland valleys will experience considerable heat, coastal areas will see milder conditions due to a persistent (if a little diminished) marine layer.
There's also a slight chance of showers or thunderstorms this weekend, mostly impacting the southern areas and higher elevations.
Today's Warm-Up:
Today's weather is already reflecting the influence of a "cut-off low" pressure system to our south. While this low is distant, it's allowing a broad ridge of high pressure to build over the southwestern United States.
This combination is leading to a significant warming trend. We're seeing scattered high clouds across much of the Central Coast this afternoon, and low clouds are persisting along the beaches, especially along the immediate coastline. Today, temperatures are a few degrees warmer in far interior locations, while other areas remain near normal to slightly below normal under the clouds.
There is a tropical storm well to the south, south of Cabo San Lucas. It is not going to have any direct impact on us however some indirect moisture will be drawn up by that upper low in SoCal.
Friday: The Hottest Day
Tomorrow, Friday, is still forecast to be the warmest day. Temperatures are expected to be 8 to 16 degrees above normal, with highs in the 90s to just above 100 degrees across the interior valleys and lower mountains. This extreme heat is due to the continued strengthening of the high-pressure ridge, which will compress the atmosphere and lead to significant warming.
A Heat Advisory has been issued for interior San Luis Obispo and Santa Barbara Counties for Friday. Some daily temperature records, notably in Paso Robles (where the current record is 102), could be challenged or broken.
The high pressure aloft will also significantly compress the marine layer, meaning that cool, moist air will be mostly confined to the coastal plains on Friday. Dense fog is possible in this shallow marine layer, especially Friday night into Saturday morning, potentially impacting coastal waters.
Saturday: Slight Cooling, Weekend Rain Chances Begin
On Saturday, the ridge of high pressure starts to break down, and onshore flow will increase, leading to a slight cooling. However, temperatures will remain well above normal. The cut-off low to our south will begin to shuttle moisture into the region. This means showers and thunderstorms will be possible (10-20% chance) from Saturday afternoon through Sunday night, focused south of Point Conception but the chances are greater than zero locally even if they are not high.
Sunday: Temperatures Drop, Unsettled Conditions
By Sunday, the cut-off low is favored to move eastward, with its center of circulation over the northern Baja Peninsula. This will cause local atmospheric heights to fall rapidly, leading to a significant drop in temperatures. Highs on Monday are likely to be several degrees below normal.
Looking Ahead to Next Week:
A cooling trend is expected to continue into early next week. By Tuesday, overall low pressure will persist, with an unseasonably strong trough potentially dropping into the region. However, by Wednesday, a warming trend is expected to kick off, lasting through the end of next week.
Stay safe in the heat this week, and keep an eye on the forecast for updates on the weekend's changing conditions.
