489 FXUS66 KMTR 140448 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 948 PM PDT Sun Apr 13 2025 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 1246 PM PDT Sun Apr 13 2025 Quiet weather is on tap with a warming trend starting today and continuing into the early portion of the week. For midweek to late week, a brief cooling trend is expected with the potential for warmer weather returning for the weekend. && .UPDATE... Issued at 845 PM PDT Sun Apr 13 2025 The forecast remains on track with no updates needed this evening. Satellite imagery shows an Otter Eddy in the Monterey Bay with stratus generally shifting to the south. An interesting upper- level pattern will yield interesting stratus coverage tonight. With the region being largely under split flow with a cutoff-low undercutting a shortwave ridge, the smallest amount of forcing will dictate stratus coverage. As such, HREF and NBM suggest that stratus will make a triumphant return in the early morning hours of Monday, primarily to coastal locations. Sarment && .SHORT TERM... (This evening through Monday) Issued at 1246 PM PDT Sun Apr 13 2025 Satellite shows mostly clear skies throughout the region. Temperatures reported about 5-10 degrees above normal today, which is on track as the upper level ridging promotes the warming trend going into Monday. Tonight temperatures is expected to drop to mostly 50s, but max temperatures on Monday are expected to reach mid 70s to mid 80s in the interior regions, and upper 60s to low 70s along the coast. Keep in mind that the warm temperatures have put most of our inland areas under a minor HeatRisk for those extremely sensitive to heat. Please take the proper precautions and stay hydrated. && .LONG TERM... (Monday night through next Saturday) Issued at 1246 PM PDT Sun Apr 13 2025 The upper level pattern begins to change on Tuesday as a low pressure system that sits off the coast of Southern CA, starts to gradually move northeast and push the ridge out to the east. This will allow some cooler temperatures, onshore winds, and increase in cloud cover. NBM continues to show chances for thunderstorms is less than 10% and the GFS and NAM shows PWAT values remaining under 0.80" for our area on Tuesday through Thursday, but SPC does have most of the eastern portion of CA highlighted for possible isolated thunderstorms due to instability from the cold air mass and daytime heating. As we get closer to mid-week and continue to monitor the placement of the trough, confidence will increase on determining the chances for thunderstorms. Cluster analysis does favor a ridge pushing in from the eastern Pacific, bringing another chance for warmer temperatures and drier condition this upcoming weekend. && .AVIATION... (06Z TAFS) Issued at 947 PM PDT Sun Apr 13 2025 Winds continue to reduce into the night and look to become light for most areas. Cloud cover will move slowly into the region from the south overnight. This will lead to IFR CIGs filling over HAF and SNS in the late night, and some CIGs affecting MRY for Monday morning. The North Bay terminals look to see moments of fog into early Monday morning, and lasting through the mid morning. While all other terminals look to see VFR by the end of Monday morning, IFR CIGs continue for HAF beyond the TAF period. Moderate winds return for Monday afternoon, but wind directions will be more affected by localized effects. IFR CIGs will build inland into that evening. Vicinity of SFO...VFR through the TAF period. Expect winds to reduce into the early night becoming light through the late morning. West winds will increase again into Monday afternoon, but only to moderate speeds before becoming light again into that night. SFO Bridge Approach...Similar to SFO Monterey Bay Terminals...Winds are becoming light around the terminals. Cloud cover is rotating around the Monterey Bay around an eddy, transporting cloud cover counter-clockwise. Said eddy pushed IFR CIGs into SNS but are now pulling them toward the northern portions of the Monterey Bay. Low clouds move up the Big Sur Coast and into the Monterey Bay in the late night as the oscillation begins to fall apart. MRY will initially be sheltered from these clouds, with SNS filling in the late night through much of the morning. Inconsistent CIGs look to affect MRY in the early to late morning before cloud cover retreats back to into the bay itself. As terminals return to VFR, moderate winds build for Monday afternoon. IFR CIGs return in the early evening on Monday as winds become light && .MARINE... (Tonight through next Saturday) Issued at 947 PM PDT Sun Apr 13 2025 Winds weaken into the night, but become moderate again into Monday. Moderate seas of 7 to 10 feet will gradually subside throughout the night, with waves falling below Small Craft Criteria. Seas build toward the latter half of the work week with breezy winds arriving later that weekend. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ SHORT TERM...SO LONG TERM....SO AVIATION...Murdock MARINE...Murdock Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea