Hydrometeorological Discussion National Weather Service / California Nevada RFC / Sacramento CA 810 AM PDT Thu Apr 18 2024 ...WARM AND GENERALLY DRY INTO MONDAY... ...CHANCE OF PRECIP ON TUESDAY AS A LOW APPROACHES THE CA COAST... .METEOROLOGICAL CONDITIONS (THU AM - WED AM)... An upper level ridge of high pressure off the west coast today weakens as a weak disturbance approaches Point Conception area tonight and moves onshore Friday. Today should be a dry day but may see cumulus development over the Central/Srn Sierra and Srn NV with a possible isolated shower on Friday afternoon/evening. A shortwave trough approaches the Pac NW/ B.C. with the trailing end of the associated weak front possibly clipping the far NW CA Coast Saturday. This may bring some light precip to the far NW CA coast and along the Srn OR Cascades Saturday. A weak shortwave ridge of high pressure moves over the region Sunday into Monday bringing dry conditions. An upper level low forms over the Eastern Pac around 133 W and 33N Monday night and gets closer to the CA coast Tuesday into Wednesday. Models and ensemble members vary with the timing and strength and track of this low for low confidence in the details of the forecast mid-week next week. The 06Z GFS and the 00Z EC show the low moving se and moving onshore around Baja on Wednesday (GFS) and Thursday (EC) and the Canadian has low farther north off the Nrn CA coast Tuesday night into Wednesday. The forecast is mainly a mix of NBM and WPC for Tuesday with a chance of light precip over the north and along the Srn CA coast. Max temps near normal to around 10 degrees above normal today and Friday (except along the Srn CA coast up to 10 degrees below normal on Friday). Max temps generally 5 to 15 degrees above normal over the weekend and into Monday except up to 10 degrees below normal for the NW CA coast Saturday and Central and Srn CA coast Monday. Max temps cool to generally near normal to 10 degrees below normal for most of CA on Tuesday and remain around 5 to 15 degrees above normal for NE CA and most of NV. Overnight lows generally near normal to up to 15 degrees above normal. |