####018005067#### FXUS63 KGRB 032041 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 341 PM CDT Fri May 3 2024 Forecast discussion for routine afternoon forecast issuance .KEY MESSAGES... - Scattered showers and isolated thunderstorms are expected Saturday into Saturday evening, with additional showers and thunderstorms Tuesday through Wednesday. - A few rivers will remain at or reach bankfull stage into the weekend. && .DISCUSSION... Issued at 340 PM CDT Fri May 3 2024 Short Term...Tonight and Saturday Deep mixing allowed temperatures to soar into the middle 60s to lower 70s, caused winds to gust to 25 to 35 mph over far N WI, and resulted in pockets of low relative humidity in the sandy soil regions of northern and central WI this afternoon. Mostly clear skies will give way to a gradual increase in mid and high level clouds overnight, but dry conditions will prevail. Considered the possibility of patchy fog overnight, but a well- mixed air mass, increasing boundary layer winds overnight and shorter spring night argued against any mention at this time. Look for low temperatures to drop into the 40s. On Saturday, a dry start to the day will give way to a band of light to moderate showers along and ahead of a cold frontal passage. The showers will be aided by a weak surface wave lifting northeast along the front, plus upper divergence in the RRQ of a 110 kt jet streak and weak short-wave energy. There is a general consensus for a narrow ribbon of weak instability (SBCAPE 200-400 j/kg) developing over the Fox Valley and lakeshore areas in the afternoon, so have kept a mention of a few thunderstorms there. Showers should arrive in NC/C WI mid to late morning, and Fox Valley/lakeshore early to mid afternoon. High temperatures will range from the upper 50s and lower 60s west and near Lake Michigan, to 65 to 70 across inland areas of NE/EC WI. Long Term...Saturday Night Through Friday Saturday evening/night...Rain and a few thunderstorms will be ongoing across far eastern WI into Saturday evening as a cold front and mid-level shortwave tracks over the area. Not anticipating for these storms to be strong or severe as the couple hundred J/kg of instability over the area during the afternoon will rapidly decrease into the evening. The showers and storms will exit the state by 06z Sunday. Sunday through Monday...High pressure and upper-level ridging moves over the area during this time period, leaving dry weather and mostly sunny skies across the forecast area. Temperatures will rise above normal for both days with highs ranging from the mid 60s to low 70s inland, and upper 50s to low 60s along the lakeshore. Slightly elevated fire weather conditions are possible on Monday as afternoon RH values will be in the 30s and southeast winds may gust to 20 to 25 mph. Locations across the north would be of greatest concern where green up has not fully occurred. Rest of the extended...Models are still in agreement with an upper- level trough developing over the Northern Plains Monday into Tuesday. This will leave the forecast area in the southerly flow ahead of the trough, allowing southern stream energy and moisture to increase and lift into the Middle and Upper Mississippi Valleys. Although there are still some timing and placement differences, especially when the precip will end, Tuesday into Tuesday evening appears to be the best timing for widespread rain and embedded thunderstorms. Despite being in the warm sector, the timing of the precip may hinder severe potential across the forecast area and keep it confined south of the area. Will continue to monitor as there is still plenty of time for the details to be ironed out over the coming days. Details for the remainder of the extended become very messy, but models agree with additional chances for precip at times through the rest of next work week. && .AVIATION...for 18Z TAF Issuance Issued at 1235 PM CDT Fri May 3 2024 Expect VFR conditions to prevail through the TAF period, with patchy mid/high clouds expected into early Saturday, then thickening and lowering clouds in NC/C WI as showers arrive toward midday. Considered the possibility of patchy fog tonight, but the air mass has become well mixed this afternoon (warm temps and low dew points leading to large dew point depressions) and boundary layer winds will be increasing to 20 to 25 kts late tonight. Models are hinting at some low clouds coming off Lake Michigan (near MTW) Saturday morning, but confidence is too low to mention a ceiling at this time. Gusty west winds will drop off quickly late in the day, become light SE overnight, then moderate SE-S later Saturday morning. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Kieckbusch/Kruk AVIATION.......Kieckbusch ####018006002#### FXUS65 KVEF 032042 CCA AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 120 PM PDT Fri May 3 2024 .SYNOPSIS...A potent storm system dropping down from the Pacific Northwest will move across the region Saturday and Sunday bringing widespread strong winds and much cooler temperatures. High elevation snow in the southern Sierra Saturday will spread across parts of southern Nevada Saturday night and Sunday leading to a dusting of snow in the mountains. Improving conditions are expected Monday though temperatures will stay a little below normal much of the week. && .SHORT TERM...Through Sunday night. Tranquil weather will continue through tonight then winds will increase significantly Saturday morning through the afternoon as a cold upper low digs over northern California/northwest Nevada. This system could be be seen on recent satellite loops off the Pacific Northwest Coast and looks vigorous with a clear cold core surrounded by a substantial moisture plume rounding its base. Model ensembles are in good agreement at tracking the center of the closed low across northern/central Nevada Saturday night and Sunday before opening it up as it pulls away to the Rockies Sunday night. This will place the base of the low and the area of strongest winds directly over our region. The main impact for our region will be widespread strong to high winds. The High Wind Watch was upgraded to a High Wind Warning for Inyo, Nye, Esmeralda and western Clark counties...including the Spring Mountains/Red Rock Canyon. The latest high res model cross sections indicate the potential for at least 60 mph downslope winds in the Owens Valley and Saturday evening between 00z and 06Z, and in the east facing slopes of the Spring Mountains between 06Z and 15Z Sunday. Gusts near the peaks of 70-80 mph are indicated. Wind Advisories were issued for the rest of Clark, Lincoln, Mohave and San Bernardino counties where gusts of 40- 55 mph will be common. Winds will decrease late Sunday afternoon and evening on the back side of the exiting trough. Precipitation will begin in the southern Sierra Saturday afternoon then spread across central and southern Nevada Saturday night and Sunday. Up to 2" of snow is forecast for Aspendell, and up to 12" near the Sierra crest above 10000 feet. Snow levels are forecast to drop to near 5000 feet across central and southern Nevada by Sunday morning when probabilities for precipitation range from 30-60% between the Spring Mountains and Rachel and Pioche. 1-2" of snow will be possible for the mountains of northern Lincoln County. 1" of snow or less can be expected for upper Kyle and Lee Canyons in the Spring Mountains and only a dusting for Rachel and Pioche. Temperatures will start to cool across the northern areas on Saturday with little change over the Mojave Desert region. Highs then drop 15-20 degrees areawide on Cinco de Mayo. This will be exceptionally cool for early May. In fact, the forecast high of 67 for Las Vegas Sunday is only two degrees warmer than our low maximum record of 65 set on May 5, 1973. .LONG TERM....Monday through Thursday. As the weekend system moves out, our area will be left under mostly zonal flow with a touch of a NW component. This pattern looks to linger through most, if not all, of the work week as persistent troughing remains just to our north. At the surface, this results in breezy afternoons with highs roughly 3-8 degrees below normal across the area. We'll remain dry as the troughing to our north has very little moisture to work with. PoPs stay below 10% through Thursday. && .AVIATION...For Harry Reid...Southwest winds of 10-15kts are expected to develop again this afternoon and continue into the early evening. Winds should fall below 10kts by mid-evening and remain less than 10kts through 15Z Saturday morning. After that, increasing southwest winds are forecast, with speeds increasing to above 20kts by late morning. Winds will continue to increase Saturday afternoon and evening, with a greater than 60% chance of gusts in excess of 45kts developing by tomorrow evening and continuing into Sunday morning. Winds will gradually decrease Sunday, but gusts over 30kts will remain likely through at least 00Z Monday. VFR conditions will prevail through the TAF periods, although an increase in clouds AOA 15kft AGL is expected tomorrow afternoon and evening. For the rest of southern Nevada, northwest Arizona and southeast California...Las Vegas area TAF sites will follow similar trends to KLAS, with gusts over 30kts developing by early Saturday afternoon. KBIH will light northerly winds of less than 12kts through Saturday morning. Winds will increase after 16Z, with westerly winds over 35kts possible at KBIH after 20Z, and gusts over 50kts will be possible along the eastern slopes of the Sierra late Saturday afternoon into evening. Westerly winds will continue at KDAG with gusts over 30kts likely by Saturday morning, increasing to greater than 40kts by Saturday afternoon. In the CRV, light southerly winds will persist into tonight before increasing Saturday morning. Gusts over 30kts are likely at KEED and KIFP after 18Z tomorrow. VFR conditions will prevail at all sites through the TAF period, although an increase in clouds AOA 12kft AGL is expected tomorrow afternoon and evening at KBIH and Vegas area sites. .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Adair LONG TERM...Woods AVIATION...Planz For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter ####018005337#### FXUS66 KSGX 032042 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 142 PM PDT Fri May 3 2024 .SYNOPSIS... This weekend expect cloudy and cool conditions with gusty winds in the mountains and deserts and periods of showers in and west of the mountains. Southwest to west winds will increase in strength through the day Saturday, peaking Saturday night into early Sunday. Some drizzle may occur Saturday morning, but the the best chances for showers and accumulating rain will also be Saturday night into early Sunday. Dry and warmer conditions expected for next week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... A low pressure system is on track to move inland through California on Saturday night and dig into the Great Basin on Sunday. This system will bring cooler, cloudier, windier (in the mountains and deserts), and wetter conditions (in and west of the mountains) to Southern California this weekend. Southwest to west winds will begin to increase Saturday afternoon, peaking in strength Saturday night into Sunday, gradually diminishing into Sunday night. Winds will be strongest on the desert mountain slopes, through passes, and into portions of the deserts. Peak gusts of 55 to 65 mph expected. There is a 30 to 40 percent chance that a few isolated gusts to 70 mph are possible in wind prone locations on the desert foothills of the San Bernardino mountains and near the San Gorgonio Pass late Saturday night. Winds will gradually weaken into Sunday night. For much of next week, a broad troughing pattern over the United States will enhanced the onshore pressure gradient, bringing periods of breezy westerly winds to the mountains and deserts each afternoon and evening. A weak coastal eddy is expected to help deepen the marine layer overnight. This could result in patchy drizzle for the coast and valleys tonight into Saturday morning. The best chance for showers and accumulating rain is late Saturday night into Sunday morning. Shower coverage will be scattered with mostly light amounts expected to accumulate. A few hundredths to a tenth of an inch of rain are expected for the coast and valleys. One-quarter to locally one-half inch expected on the coastal slopes of the mountains with the greater amounts most likely on the coastal slopes of the San Bernardino County mountains. A trace of snow is expected above 7000 ft. This will be a quick moving system and dry conditions are expected by early Sunday afternoon. Highs Saturday are expected to be 3 to 5 degrees below average for the coast and valleys, and near average for the deserts. Sunday will be even cooler, especially for inland areas with highs 10 to 15, locally up to 20 degrees below average for the valleys, mountains, and deserts. Cold conditions expected Monday morning, especially in the High Desert where lows are forecast to fall to the mid to upper 30s. The highs on Monday will make up for the cool conditions Sunday and Monday morning, with temperatures as much as 10 to 15 degrees warmer than Sunday for the mountains and High Desert. Conditions are expected to gradually warm into the end of next week. && .AVIATION... 032030Z...Coasts/Valleys/Foothills...SCT to locally BKN clouds near the coast based at around 2000-2500 feet MSL. Low clouds based at 1200-1800 feet MSL will spread ashore and inland this evening push into foothills by 13Z Saturday. Bases will rise to around 2000 feet MSL with tops up to 3500-4000 feet, obscuring some higher terrain. Scatter out Saturday will be slow and gradual, around 17-20Z. Otherwise...Clear skies with unrestricted VIS will continue through tonight, with increasing high clouds above 15000 feet MSL Saturday. && .MARINE... No hazardous marine conditions are expected through much of Saturday. Stronger and gusty west to northwest winds Saturday evening through Sunday evening will generate hazardous boating conditions, especially in the outer waters. Check the Small Craft Advisory for details. No additional hazardous marine conditions are expected Monday and beyond. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Wind Advisory from noon Saturday to 8 PM PDT Sunday for Apple and Lucerne Valleys-San Bernardino County Mountains-San Gorgonio Pass Near Banning. Wind Advisory from 3 PM Saturday to 8 PM PDT Sunday for Coachella Valley-Riverside County Mountains-San Diego County Deserts-San Diego County Mountains. PZ...Small Craft Advisory from 3 AM to 10 PM PDT Sunday for Coastal Waters from San Mateo Point to the Mexican Border and out to 30 nm. Small Craft Advisory from 6 PM Saturday to 3 AM PDT Monday for Waters from San Mateo Point to the Mexican Border Extending 30 to 60 nm out including San Clemente Island. && $$ PUBLIC...CO AVIATION/MARINE...MM