Hydrometeorological Discussion National Weather Service / California Nevada RFC / Sacramento CA 635 AM PDT Wed May 13 2026 ...A FEW SHOWERS REMAIN FOR THE NORTH COAST AND UPR KLAMATH TODAY... ...POSSIBILITY OF SHOWERS NORTHEAST LATER SAT INTO SUN... .METEOROLOGICAL CONDITIONS (WED AM - TUE AM)... The upr ridge centered over the Four Corners is being displaced farther downstream of the region along the front range of the Rockies this morning...as a s/wv trof and cold front moves inland across the Pacific Northwest and northern CA. Some light precip was observed overnight...mainly confined to coastal locations near and north of Cape Mendocino with anywhere from a few hundredths of an inch (south) to 0.25-inch (Smith River basin). May still see some light precip this morning across the immediate northern CA coast and possibly over the crest of the southern OR Cascades. This system will lift off toward the east-northeast toward the northern Rockies today...leaving behind an upr ridge to the southwest of the CA coast near 30N/140W and westerly onshore flow between 40N and 50N primarily taking aim at the Pacific Northwest. For Thursday into Friday...a couple disturbances will move through the westerly flow aloft and primarily impact southern BC and the Pacific Northwest. The latter of the two systems will be a tad stronger and drag some light precip closer to the upper Klamath River basin on Saturday. As this s/wv trof on Friday moves inland on Saturday...look for it to slow its eastward progress and buckle the flow as it begins to dig toward the southeast over the Great Basin. This may generate some light precip over the upper portions of the Humboldt River basin in northeast NV. At this time...amounts look to be generally near or less than 0.25-inch. Upstream over the immediate west coast...look for dry northwest flow aloft. Freezing levels are currently showing a sharp gradient near the CA/OR border...ranging from 7000- to 11000-feet. Elsewhere across the region freezing levels are from about 12000- to 14000-feet with the highest values to the east. Thursday and Friday will generally show freezing levels from 9000-feet (north) to 14000-feet (south). Then as the system digs toward the Great Basin...freezing levels will dip a bit across northern areas from 6000- to 9000-feet and 10000- to 14500-feet across the southern half of the area. By early Tuesday with the more amplified flow...the gradient becomes more northeast to southwest with 8500-feet over northeast NV to about 13000-feet or so along the immediate coast. 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. |