####018004357#### FXUS66 KMTR 201204 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 504 AM PDT Wed May 20 2026 ...New AVIATION, MARINE... .KEY MESSAGES... Updated at 1036 PM PDT Tue May 19 2026 - Diurnally driven winds, with onshore winds during the afternoon and early evening. - Above normal temperatures continue through midweek with seasonal temperatures returning late week. - Warm and dry weather through Thursday leads to elevated fire weather concerns for the interior Bay Area and Central Coast. && .SHORT TERM... Issued at 1036 PM PDT Tue May 19 2026 (Tonight through Thursday) Little change in the forecast as high pressure slowly creeps into Northern California today. Satellite imagery this evening shows high clouds sliding down the West Coast, with much of the Bay Area likely seeing some cirrus. With the current data, temperatures look to be on track; however, if we're not able to get radiational cooling, our temperatures for tonight might be low/cool. This would be because the clouds act as blanket, allowing less heat to escape at night. It'll be something to keep an eye on over the next few hours. In terms of Wednesday, if you guessed, "No pattern change. Ha, this means another day of warmer weather", you'd be correct! A potential fly in the ointment is if the marine layer attempts to manifest around 500 feet. This might keep temperatures a few degrees cooler along the immediate coast, but elsewhere temperatures should be similar to Tuesday, perhaps a few degrees higher. && .LONG TERM... Issued at 1036 PM PDT Tue May 19 2026 (Thursday night through next Tuesday) No major changes to the extended forecast. Upper level troughing looks to keep hold over the western US, while the Pacific high pushes even more into northern California on Thursday. With the high being a bit more pronounced, another warm day will be on tap. After that, guidance has flow becoming quasi-zonal for a brief period before troughing returns on Friday. The marine layer looks to be around 500ft on Thursday, deepening to around 1000ft by Friday and then lasting through the weekend. With onshore flow, a deeper marine layer, and troughing through the weekend the NBM's temperatures are bit too warm. Opted to start trending towards slightly cooler temperatures given the ensembles and cluster analysis. But there is a chance ridging wins out and temperatures might warmer. Definitely something to keep an eye on over the next few days. && .AVIATION... (12Z TAFS) Issued at 503 AM PDT Wed May 20 2026 VFR at the big three this morning and expect that to continue despite some stratus forming offshore. Guidance was a little too aggressive in bringing in stratus elsewhere and thus have cut back on stratus this morning. HAF and SNS are experiencing some hz/br drop the flight CAT. VFR this afternoon gusty onshore flow. Gusts 15-20kt seems reasonable. For tonight, marine layer currently off the coast will move locally inland with highest conf for HAF and MRY/SNS. Vicinity of SFO...VFR. NW winds ramp up this afternoon with gusts to 20kt. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...MRY is VFR, but enough low level moisture is at SNS to have occasional br/hz. Much higher conf for stratus intrusion tonight into Wednesday. && .MARINE... (Today through Monday) Issued at 432 AM PDT Wed May 20 2026 A weak frontal boundary to the north will maintain fresh to strong northerly breezes and rough seas over the outer waters north of Pigeon Point through early Thursday. Elsewhere, moderate to fresh northerly breezes and moderate seas will prevail. Conditions improve into the weekend as seas and northwesterly breezes become moderate. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 3 PM PDT Thursday for Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...KR LONG TERM....KR AVIATION...MM MARINE...MM 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 ####018006444#### FXUS62 KJAX 201205 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 805 AM EDT Wed May 20 2026 ...New AVIATION, UPDATE... .KEY MESSAGES... For the latest NE FL and SE GA Daily Key Messages please visit: https:/www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf - Moderate Risk Of Rip Currents at All Area Beaches through Friday - Patchy to Areas of Fog Tonight, Locally Dense inland Southeast GA - Daily chances for mainly afternoon thunderstorms will increase this week and weekend. && .UPDATE... Little change in the forecast for today with generally mostly sunny skies except for some cumulus forming during the late morning and through the aftn and a few high clouds at times. A couple of small convergent lines along the Duval and St Johns coasts may generate some sprinkles this morning and would appear to weaken by mid morning. Highs still look to be lower 90s inland and upper 80s coast. A few locations may hit 95 well inland today. Precip chances this aftn/evening remain fairly low based on latest HREF and HRRR for inland northeast FL. The isolated showers offshore (>40 miles) of northeast FL are associated with a inverted trough and may briefly increase through midday then settle back down and likely to dissipate by the evening. && .NEAR TERM /THROUGH TONIGHT/... Main Highlights This Period: - Solid Moderate Rip Current Risk at NE FL/SE GA beaches - Locally dense fog possible inland late night/early morning hours High pressure will be centered to the northeast of the region through Tonight. This will continue a southeast steering flow across the region. Moisture remains limited in the mid/upper levels and is expected to only trigger widely scattered showers and storms during the afternoon/evening hours over inland areas, with the main focus along the I-75 corridor of inland NE FL. Isolated strong storm possible with gusty winds, but severe weather is not expected. Max temps will remain above normal with highs in the lower 90s inland, upper 80s I-95 corridor and middle 80s along the Atlantic Coast. Low temps falling into the 60s over inland areas will support patchy to areas of fog formation, with locally dense fog possible around sunrise both mornings, mainly along the I-10 corridor northward across most of inland SE GA. The onshore flow will keep the Atlantic Coastal milder with lows in the lower/middle 70s. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... Main Highlights This Period: - Daily isolated thunderstorms each afternoon as the Atlantic sea breeze pushes inland towards the I-75 corridor. Pattern of diurnal showers and storms will continue with convection becoming less inhibited by Friday as the influence of high pressure ridging over the forecast area diminishes and prevailing flow shifts to become more southerly, bringing in more moist conditions with PWAT values potentially rising to levels between 1.8 and 2 inches. Temperatures will be well above average through the end of the week with daily max temps reaching up into the lower to mid 90s over inland areas and in the upper 80s along the coast. Overnight low temperatures will drop down into the lower to mid 70s for inland areas and in the mid to upper 70s for areas near the shoreline. && .LONG TERM /SATURDAY THROUGH TUESDAY/... - Hot temperatures continue through the weekend - Increasing chances of showers and storms into and through the upcoming holiday weekend into next week. Diurnal convection will become more widespread by Saturday and Sunday as prevailing flow over the forecast area continues to be from out of the southeast and south with afternoon thunderstorm developments having a a potential for heavy rainfall with stronger slower moving storms leading to localized flooding over affected areas. Temperatures are expected to remain above the seasonal average through the weekend and into next week. && .AVIATION /12Z WEDNESDAY THROUGH 12Z THURSDAY/... Some mist and fog around VQQ, but otherwise prevailing VFR through Wednesday evening, except for brief possibility of MVFR cigs during the morning hours. Rain chances still look too low to include in the TAFs, but, if any, would be at SGJ, VQQ, and GNV with a VCSH or VCTS at best for now. Will monitor radar and satellite trends in the aftn if any vicinity wording is needed in these TAFs. Winds are calm to light at 12z and will become east and southeast up to 10-15 kts with gusts of 18-20 kt, with the strongest easterly wind for SGJ, CRG, and SSI. Winds will diminish tonight. && .MARINE... High pressure will be centered to the east northeast this week and through the weekend. Mainly southeast flow will continue through the period with a daily sea breeze near the Atlantic Coast. Rip Currents: Solid Moderate Risk through the end of the week with surf/breakers in the 2-3 ft range. Potential High Risk for the holiday weekend with an uptick in surf/breakers back into the 3-4 ft range. && .FIRE WEATHER... - Patchy High Dispersions This Week The combination of deep mixing and sufficient southeasterly transport winds will generate generally good to high dispersions inland each afternoon this week. Persistent onshore flow will allow moisture to continue filtering into the area, leading to MinRH values remaining above critical levels. With the onshore flow from the Atlantic, convective activity will be possible each afternoon to evening as the sea breeze pushes inland. By the weekend, increase chances and coverage of showers and storms is expected. FOG POTENTIAL AND OTHER REMARKS: Isolated thunderstorms through the week. each day Tuesday onward. Patchy fog possible this morning and Wednesday mornings for inland locations. && .PRELIMINARY POINT TEMPS/POPS... AMG 92 66 91 68 / 10 10 20 10 SSI 84 72 86 77 / 0 10 0 0 JAX 89 68 92 73 / 10 0 20 10 SGJ 87 70 90 75 / 10 0 10 10 GNV 93 68 94 72 / 20 20 20 20 OCF 93 69 92 73 / 30 30 30 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. MARINE...None. && $$ ####018003890#### FXUS63 KGRB 201205 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 705 AM CDT Wed May 20 2026 Updated aviation portion for 12Z TAF issuance .KEY MESSAGES... - Frost or freeze headlines may be needed tonight as lows fall into the low to mid 30s over the Northwoods. - Below normal temperatures continue throughout the week, warming back up during the Memorial Day weekend. - Dry through at least early Friday with periodic rain chances throughout the Memorial Day weekend. && .DISCUSSION... Issued at 228 AM CDT Wed May 20 2026 Early Morning Analysis...Despite surface high pressure nudging into the area from the west early this morning, isolated light rain showers or sprinkles were occurring over north-central WI aided by a 500mb vort max overhead, with mostly cloudy skies occurring elsewhere. The cloud cover will limit any frost development from occurring this morning especially in far north-central WI where temperatures are most favorable. Rain Chances...The surface high pressure is progged to reside over the area today into Friday, keeping dry weather in place for the remainder of the work week. Model guidance is suggesting the next chance for rain arrives Friday night into Saturday, as a southern stream system lifts across IL/IN/MI. This would leave the forecast area in the north/northwest precip shield of this system, minimizing the potential for any thunderstorms. However, the latest guidance is indicating the southern stream system may track further to the south and east, lowering the potential for precip in the area for Friday night into Saturday. Trailing behind this system is an upper-level trough/frontal passage that looks to bring another chance for rain sometime between Saturday night into Sunday, which may include the potential for thunderstorms. There are also signs of a shortwave moving over the area for Memorial Day, which could also bring rain and thunderstorm potential. Despite these features, the Memorial Day holiday weekend does not appear to be a washout, and more along the lines of periodic chances for showers and storms. Temperatures/Frost Potential...Below normal temperatures are expected through Saturday, with today and Thursday being the cooler of the days with highs in the mid 50s to mid 60s. Given the cooler temperatures tonight (lows in the low to mid 30s across the Northwoods and upper 30s to low 40s elsewhere) and high pressure overhead, where clouds clear and winds become calm, anticipate frost development, mainly across the Northwoods. A Frost Advisory will likely be needed. High temps gradually warm into the 60s for Friday and Saturday before rising into the 70s for Sunday, and potentially into the 80s for early next week. && .AVIATION...for 12Z TAF Issuance Issued at 704 AM CDT Wed May 20 2026 Low-end VFR clouds with cloud bases of 3500 to 5000 ft AGL prevailed across the region this morning. A few sprinkles were also being observed at some locations in central and north-central WI, but will have no impacts to aviation. Anticipate the low-end VFR clouds to stick around for much of the morning before rising this afternoon, in addition to a cu field developing. Clouds will gradually scatter out late this afternoon/evening, however, high clouds will also be in the region. Some clearing is expected overnight as well. Light northwest winds are expected for much of the day before a lake breeze pushes onshore from Lake Michigan, causing winds to switch to the east late this afternoon and evening, reaching the central WI TAF sites around 04z Thu. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Kruk AVIATION.......Kruk ####018005213#### FXUS62 KTBW 201205 AFDTBW Area Forecast Discussion National Weather Service Tampa Bay Ruskin FL 805 AM EDT Wed May 20 2026 ...New UPDATE, AVIATION... .KEY MESSAGES... - Above normal temperatures are expected each day through the week. - Thunderstorms are expected to develop each day, mainly in the afternoon into the evening hours. - Severe to extreme drought conditions continue for most areas. && .UPDATE... Issued at 805 AM EDT Wed May 20 2026 An overall lighter low level east to southeast flow across the region this morning, sea breeze regime 2, which should allow the west coast sea breeze to develop and move inland to around or just east of the I-75 corridor later this afternoon. There will be enough moisture, precipitable water 1.4 to 1.6 inches, combined with daytime heating and the sea breeze to see scattered to numerous afternoon and evening convection. With the lighter flow the higher rain chances today are expected to be around or just east of the I-75 corridor. Current forecast looks good with no changes needed. && .AVIATION... (12Z TAFS) Issued at 805 AM EDT Wed May 20 2026 Some areas of MVFR ceilings will be possible this morning as daytime heating gets underway, then more MVFR/local IFR conditions will be possible this afternoon and evening in scattered showers and thunderstorms. Otherwise, VFR conditions should prevail with east to southeast at 7 to 11 knots this morning. Expect the bay/sea breezes to develop early afternoon shifting winds to westerly at TPA, PIE, and SRQ, otherwise the overall east to southeast flow will persist into this evening before diminishing to 3 to 6 knots overnight. Gusty and erratic winds will be possible near showers and thunderstorms. && .DISCUSSION... Issued at 1214 AM EDT Wed May 20 2026 Not much change to the overall forecast reasoning. Little change to the overall pattern through the remainder of the week and the upcoming weekend. Surface high pressure over the western Atlantic will extend across the Florida peninsula with the ridge axis located north of the forecast area. This will produce east to southeast boundary layer flow across the peninsula for the next several days. The west coast sea breeze boundary will develop each afternoon with the southeast flow holding the boundary over the coastal counties. The easterly flow isn't quite as strong as yesterday, which will allow the boundary to push about 20 to 30 miles further inland, which will also shift highest pops today to the interior coastal counties. Scattered to numerous showers and thunderstorms will develop each afternoon along the boundary with the greatest areal coverage from the Tampa Bay area and south. Stronger storms will be capable of producing wind gusts of 40 to 50 MPH and small hail. An U/L low east of the Bahamas will meander off the east coast of Florida through the end of the week. This will in effect create lower heights over west central and southwest Florida which will aid in increasing convective instability. The U/L low will exit over the weekend, and a strong U/L ridge will build over the forecast area increasing large scale subsidence over the area. Scattered to numerous afternoon showers/storms are still expected to develop along the west coast sea breeze boundary over the weekend as the increased subsidence will likely be offset by slightly warmer temps/increased low level instability. Offshore flow will aid in continuing above normal daily temperatures across west central and southwest Florida with highs generally in the lower to mid 90s away from the coast. The increased subsidence over the weekend will allow temperatures to climb even a few degrees higher. && .MARINE... Issued at 1214 AM EDT Wed May 20 2026 Surface high pressure will hold over the waters through the period with no headlines expected. Main hazard will be showers/storms developing over land each day which will push locally offshore during the afternoon/evening hours causing locally strong winds and rough seas. && .FIRE WEATHER... Issued at 1214 AM EDT Wed May 20 2026 Sufficient low level moisture will hold across the forecast area for the next several days which will keep minimum afternoon relative humidity values above critical levels. && .PRELIMINARY POINT TEMPS/POPS... TPA 91 75 91 77 / 30 30 20 20 FMY 92 73 93 75 / 60 40 50 20 GIF 92 72 92 74 / 40 30 30 20 SRQ 91 73 91 75 / 30 30 20 10 BKV 93 69 93 71 / 30 20 20 20 SPG 93 75 92 78 / 30 30 20 10 && Sea Breeze Thunderstorm Regime For Wednesday: 2 Sea Breeze Thunderstorm Regime For Thursday: 2 For additional information on sea breeze regimes, go to: https://www.weather.gov/tbw/ThunderstormClimatology && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ UPDATE/AVIATION...Close DISCUSSION/MARINE/FIRE WEATHER...Oglesby DECISION SUPPORT/UPPER AIR...Davis