Hydrometeorological Discussion National Weather Service / California Nevada RFC / Sacramento CA 130 PM PST Wed Feb 18 2026 ...SERIES OF DISTURBANCES TO MOVE IN FROM THE NORTHWEST THROUGHOUT THE WEEK BRINGING PERIODS OF WIDESPREAD PRECIP, T-STORMS, AND MOUNTAIN SNOW... .METEOROLOGICAL CONDITIONS (SHORT TERM: WED AM - SAT AM)... No major changes to the afternoon forecast as another low and frontal system/moisture plume will track southward along the California coast. Largest increases were made over San Diego and Riverside Counties where the moisture plume in combination with banded and shallow convection is looking possible tomorrow evening. These increases brought the 3-day total over the area to >1 inches across much of the foothills and above 3+ over the highest elevations. Afternoon forecasts generally followed the guidance from the NBM throughout much of the remainder of the period while working in some of the HRRR in the first 6-hour period to try and place the current shower activity correctly. Similar to the previous storms, freezing levels will be quite low during the storm tomorrow and into Friday. Levels across the north will generally sit below 3,000 feet across the north and central portions of the forecast area. .METEOROLOGICAL CONDITIONS (LONG TERM: SAT AM - TUE AM)... Forecast overall remains on track for a large surface/upper low to impact nrn/cntrl CA over the weekend. Models continue to disagree on the arrival timing of the precip, but 12z runs have trended a bit slower amongst the ensembles. The 12z det GFS/ECMWF have also shifted the low a bit northward compared to earlier runs which further pulls back the southerly/inland extent of the precip on Sunday/Monday compared to earlier. Meaning there is still uncertainty not just on the timing but on the southerly extent of precip as the det models show less spread than the ensembles/NBM. There is still good agreement that the bulk of the impacts from this larger system will be across nrn coastal CA into Shasta, but the new northward shift of the positioning has generated additional uncertainty around the northern Sierra. There is a wider range of QPF for the extended than there was before over that area with differences in the clusters again regarding how far south precip will extend. This did bring down the QPF compared to this morning by 0.50-1.50". The official forecast was a blend of the 50% NBM and the det NBM to slow down some of the precip. QPF 12z Sat-12z Tues: 3- 5.50" nrn CA coast north of Point Reyes (up to 8.50" King Range), 4- 7" Shasta, 2.50-6" northern Sierra, 1-2" central Sierra/central coast mountains, 0.10-1" southern Sierra, 0.30-1.50" rest of Bay Area/central coast, 0.75-2.50" Sac Valley, 0.10-0.75" SJ valley, and less than 0.10" around Point Conception. This low will be drawing in a warmer moist airmass raising freezing levels this weekend from sw to ne. On Saturday, the Sierra will start at around 3-6 kft rising to 5-9 kft by the evening. This increase will continue Sunday reaching 7-11.5 kft in the evening. The northward shift of the low also keeps freezing levels higher through the rest of the extended and raises them some over the weekend. 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. |