Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
794 FXUS66 KSTO 190814 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 114 AM PDT Sun May 19 2024 .SYNOPSIS... Seasonable temperatures will continue through the weekend and into early next week. Mostly sunny and dry conditions with periods of breezy winds expected through the next 7 days, strongest winds tonight-Monday. && .DISCUSSION... Breezy onshore winds made it to the Sacramento Area tonight where gusts to around 20-25 mph have been observed. Breezy winds will relax over the next few hours. Latest GOES-18 Nighttime Microphysics RGB indicates the marine low stratus deck has remained confined to western Solano County tonight, unlikely to push further east like the last two nights. Synoptically, a trough currently digging into northeastern WA will continue to dig into the Great Basin region through Monday, which will create northwesterly flow overhead today. As this trough phases with a closed upper-low which will be off the SoCal coast Monday, pressure gradients across NorCal will increase tonight- Monday, producing another breezy north wind day. Gusty north winds will begin to materialize tonight across the northern Sacramento Valley, bringing gusts of 20-30 mph, strongest winds are expected after sunrise (7am) Monday continuing through the afternoon. The NBM continues to highlight a 50-75% probability of gusts greater than 34 knots (~40 mph) in the usual north wind prone area in the western Sacramento Valley along the I-5 corridor. However, the 90th percentile NBM wind gusts only highlight an area of wind gusts to 33 knots Monday. Looking at the model spread of wind gusts, the difference between 25th and 90th is merely 5-8 knots for much of the time frame of peak winds, which are expected Monday morning through the evening. As such, not anticipating widespread 40 mph gusts (Wind Advisory criteria), and winds remaining mostly below criteria levels. Local areas of north winds to 40 mph are still possibly though, especially between Red Bluff and Colusa along I-5. Per usual with north wind days, minimum afternoon RH`s will decline, with widespread less than 15% RH values in the Sacramento Valley Monday afternoon. Temperatures will be mild, but breezy winds and low RH`s will lead to locally elevated fire weather conditions Monday across the western Sacramento Valley. Northerly flow will weaken Tuesday, allowing temperatures to increase but winds to decrease. Tuesday appears to be the warmest day in the next 7 days, with highs in the mid 80s to low 90s across the Valley/Delta and upper 60s to low 80s in the Foothills/Mountains. Continued northwesterly flow will keep the door open for more shortwaves to influence us through the rest of the week. By Wednesday, a shortwave will begin to dig into WA/OR. This system has limited moisture and will mainly bring another push of northerly winds, some clouds, and cool off temperatures a few degrees compared to Tuesday. //Peters && .EXTENDED DISCUSSION (Thursday THROUGH Sunday)... Series of upper lows progged to move through the PacNW during the extended forecast period. Associated upper troughing will extend into NorCal. Models differ with timing, track, and strength of lows leading to some forecast uncertainty with precipitation potential. NBM shows some slight chance of showers over our northern and eastern foothills/mountains Saturday afternoon into evening. Near to slightly below normal high temperatures expected through the extended period. && .AVIATION... VFR conditions over interior NorCal next 24 hrs except local MVFR/IFR possible in stratus vcnty of Delta and isolated in Sac Vly til 17z. In Central Vly, sfc wind mainly at or below 12 kts til 00z Sat, then lcl sfc wind up to 16 kts. Vcnty Delta SWly sfc wind up to 20 kts. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$