Hydrometeorological Discussion National Weather Service / California-Nevada RFC / Sacramento CA 640 AM PDT Mon Jun 8 2026 ...MAINLY LIGHT PRECIP FOR NORTHERN AREAS TODAY INTO EARLY TUE... ...WARMING TEMPERATURES UNDER BUILDING HIGH PRESSURE WED-SUN... .METEOROLOGICAL CONDITIONS (MON AM - SUN AM)... A s/wv trof and associated sfc low pressure is just off the Pacific Northwest coast this morning...tracking to the east and anticipated to shift inland later this afternoon. There also is quite an impressive fetch of tropical moisture advecting eastward...generally in the vicinity of 40N with PW values nearing 1.75-inches within the core of this feature. Look for this elevated moisture to reach and intersect the northern CA coast later today with increasing chances of precip over the higher terrain of northern CA and eventually northern NV. However...with the best forcing remaining to the north across the Pacific Northwest...only light to locally moderate precip amounts are expected today into early Tuesday. Overall amounts along the northern CA coast will be from 0.25- to 0.50-inch near Cape Mendocino to 1.00- to 1.50-inches over the Smith River basin. These amounts taper off quickly over the interior...generally less than 0.25-inch except for closer to 0.50-inch for the crest of the southern OR Cascades near Crater Lake. After this system exits to the east tomorrow...high pressure will quickly build over the eastern Pacific and nudge its way closer to the west coast. Look for increasing temperatures with afternoon highs reaching anywhere from plus 5- to plus 15-degF over seasonal normals. Models are hinting at the possibility for just enough moisture to advect northward across the southern Sierra...southeast CA...and southern NV for Friday into the weekend...which may bring a slight chance of very scattered convective showers to these areas. Amounts would be rather light. Freezing levels this morning range from 9500-feet northwest to almost 15000-feet near the CA/MX border. As the strong high pressure builds off the CA coast...look for these to be above 14000-feet for much of the region with just over 16000-feet for coastal locations for the latter portions of the forecast period. Please Note: This product may NOT be routinely updated. Please refer to the following product issued by the CNRFC www.cnrfc.noaa.gov/Daily-Briefing for a graphical summary of weather and hydrologic conditions. |