Note: A forecast will not be issued on Tuesday, 22 January. Further, more frequent absences are likely later in the month (serious health problem with my father)
Wet January 2019 at UCLA
There was plenty of leftover, storm moisture this morning. Like a deep marine layer, there were widespread low clouds west of the mountains (not necessarily as an overcast though). Some areas also had thick fog early in the morning. Some locales down in San Diego County reported light showers early this morning. Abundant low clouds continue from eastern L.A. County eastward and southward as of this writing, but the fog and showers have gone away. By tomorrow, a developing off-shore flow should purge away or at least dilute today's moist layer (i.e. low clouds should be gone).
The aforementioned, developing off-shore flow is promoting breezy weather in the higher mountains of L.A. County (some gusts to around 30 mph). Winds should increase tonight and affect some lowland areas prone to Santa Ana winds. The off-shore flow should wane tomorrow afternoon and be gone by Sunday. Peak wind gusts could reach 45 mph in the higher mountains (nothing widespread in areal coverage). Most lowland areas prone to Santa Ana winds shouldn't see significant wind (gusts to at least 25 mph), but a few spots in Ventura County may experience gusts up to 30 mph (most gusts no more than 20 mph, however). While "m expecting some brisk winds to develop on campus tonight into early tomorrow, wind gusts should remain under 20 mph (my threshold for "breezy" definition).
Unless the predicted, variable high clouds (from distant storms) wind up thicker than expected, the off-shore flow should promote widespread, 70 degree weather tomorrow/Sunday. A few locales may even flirt with the 80 degree mark (quite a contrast to the weather earlier this week). The drying atmosphere, however, should promote cooler nights in wind sheltered areas (aided by the still long, duration nights).
A storm passing through northern California will bring widespread precipitation up there on Sunday (should produce decent snowfall in the Sierras). The storm is predicted to take an "inside slider" path with respect to southern California. The computer models predict showers falling over the north facing slopes of the Tehachapi Mountains (snow levels may fall briefly to 4000 feet Sunday night into Monday morning). Up to a few inches of snow may fall above 5000 feet (dusting only below that). In addition, marine layer clouds returning Sunday night into early Monday might produce spotty showers from Orange County southward (western Inland Empire too). At most, a few hundredths of an inch rain might fall around the lower mountains slopes. For the remainder of the Southland, the predicted storm should be just a windstorm.
The "inside slider" should usher in polar air into the Southland. So, despite a mostly sunny day on MLK, Jr Day (Monday), daytime temperatures should be slightly cooler than normal west of the mountains (more decidedly cooler than normal in the interior). The wind flow pattern should become off-shore flow again on Tuesday and continue for the remainder of the work week. The breezy weather on Monday should become more restricted to Santa Ana wind prone areas on Tuesday, but peak wind gusts could still exceed 50 mph in the mountains. Some lowland areas could see wind gusts to 40 mph though it shouldn't be widespread in areal coverage nor long lasting.
The off-shore flow next week could promote warm weather comparable to what's expected tomorrow (depends on which model solution verifies). While some cooling is anticipated toward the end of next week, warmer than normal weather should last through the subsequent weekend. Some model solutions maintain warmer than normal weather right through the end of the month. A few model solutions do show a return to wet weather at the end of the month or slightly later, but being a minority model solution (for now), I'm not counting on a return to wet weather in southern California for a while (end of the month at least).
UCLA Forecasts and analyses are written by James Murakami
– posted: 2019-01-18