An excessive heat warning has been issued for inland areas Friday into Saturday

Paso Robles late spring sunset
Posted at 4:17 PM, Jun 08, 2022
and last updated 2022-06-08 21:35:57-04

Spring on the Central Coast is where we often start seeing dramatic differences between beach and coastal conditions compared to the interior. This week has been true to form with beaches in the 60s, coastal valleys in the 70s, and inland temps in the mid-90s.

Thursday thru Saturday inland temperatures look to warm additionally due to a peak in the jet stream ridge over The West. Those mid-90s highs will be 100-105 Thursday into Saturday.

Friday and Saturday look to be the warmest with an excessive heat warning in place for some interior valleys where the warmest highs are likely, an excessive heat watch is in place for other interior valleys where heat is expected but temperatures may not be AS extreme as in the warning area.

The good news-bad news situation is that the air is dry in the warmest places. This is good in that the heat index (or "feels like" temperature) is actually lower than the actual air temperature. This is because lower dew points allow sweat to evaporate and provide the body cooling. This is also a potentially bad thing in that relative humidity numbers are low. Relative humidity below 15% is always a concern for fire because fuels behave differently under 15% relative humidity.

Near the coast the situation is much less threatening. It looks like marine clouds will be patchy at best but the afternoon onshore breeze looks reliable during the interior heat run. This will mean beaches will be in the 60s and 70s and coastal valleys in the 80s. Some coastal valleys could hit the 90s Friday and Saturday.

Sunday temperatures cool significantly, if just temporarily. The ridge in the jet stream over The West is replaced by a trough Sunday and Monday and highs will drop by more than 10 degrees inland, in fact, highs in the upper 80s are likely Sunday and Monday.

This is a short-lived cool-down. Most models show warming by the middle of next week to highs near if not over 100 again. The good news is that a run of extended 100+ temps doesn't look likely with this second surge.