We expect temperatures at coastal sites to be strongly moderated by the water temperature, so that differences between the daily Tmin and Tmax are less than for inland sites. But for Tuesday in Oceanside, CA (halfway between Los Angeles and San Diego), there is a 40 F spread between the predicted Tmin and Tmax, 15 F larger than average. Why? Hint: click on the "National Weather Service Page" link and find out why they have a "Red Flag Warning" for the entire week. Let's predict Tmax for Oceanside.
Although Oceanside is right on the coast and is usually kept comfortable from the influence of the cool Pacific waters, this week is different because of strong Santa Ana winds blowing from the east. The source of the winds is the hot, dry desert, and the air warms and dries further when descending down the mountain slopes toward the coast. The effect is dramatic -- at 10 pm Tuesday the dew point in Oceanside was 42 F, then the Santa Ana winds started and it dropped to 23 the next hour and to 12 F in only 3 hours! -- Ken
|Tmax, deg F (error)