####018005194#### FXUS63 KMKX 170220 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 920 PM CDT Fri May 16 2025 .KEY MESSAGES... - Much cooler conditions this weekend through the beginning of next week, with below-normal high temps forecast each day. - Next shower and thunderstorm chances (30-60%) return late Monday through Wednesday. - Temperatures return to near-normal late next week. && .UPDATE... Issued 920 PM CDT Fri May 16 2025 Strong cold advection is underway this evening with the passage of a strong cold front. The 991 mb occluded low over east central MN will track to just north of Lake MI by 12Z Sat then to srn Quebec by late Sat afternoon. The breezy, cool and showery conditions of the occlusion will affect srn WI tnt-Sat with 40-50 percent chances of rain mainly north of Madison and Milwaukee with 20 percent chances to the south. Gehring && .SHORT TERM... Issued 318 PM CDT Fri May 16 2025 Tonight through Saturday night: Mid-level ripple of vorticity is working across WI this afternoon spurring scattered thunderstorm activity. Right now a majority of it is north of the CWA, but expecting additional development for the remainder of the afternoon through the early evening hours as the surface low tracks across northern WI and the cold front sweeps into southern WI. Seeing this evidence in the latest satellite imagery with building cu field just south of the WI/IL border. With any taller storms can expect to see stronger gusts (50-60 mph) mix down fairly easily given the steep low- level lapse rates. Also could see some hail with some of these storms as SBCAPE is hanging around 500- 1000 J/kg. So will need to monitor through the evening. Otherwise, gusty non-thunderstorm winds with gusts of 30-45 mph will continue through the afternoon and evening as the tight pressure gradient from deep low works its way across the area. Will see the southwesterly winds shift more westerly and weaken a bit as the cold front pushes through tonight. Quieter weather is expected for Saturday, but breezy westerly winds will linger on the backside of the departing low pressure system. With the cooler and drier airmass will see cooler temps for Saturday with highs in the 60s. With high pressure and ridge building over the region overnight Saturday, will see cooler temps overnight dipping back into the upper 40s and 50s. Wagner && .LONG TERM... Issued 318 PM CDT Fri May 16 2025 Sunday through Friday: Will continue to see high pressure and upper-level ridging build across the the Upper Great Lakes Sunday into Monday. This will bring drier and cooler weather to the region with lighter winds. Given these conditions will prompt the "cooler by the lake" setup with lake breezes pushing inland keeping areas cooler than inland areas. These areas can expect highs in the 50s with inland areas in the mid to upper 60s. Tuesday into Wednesday, continue to see signal for upper-level trough to undercut the ridge. This looks to track a low pressure across the Mid-Mississippi River and up the Ohio River Valley through the middle of the week. This system will provide southern WI with some nice wetting rain. Not anticipating anything severe as we should be on the northern edge/cool side of the low and dealing with more or a stratiform rain set up. Still a bit of uncertainty in how far south this low may travel and just how much rain we might see, but overall a persisting signal. Mild and comfortable temperatures are expected through mid week with highs in the 60s for inland areas and slightly cooler temperatures near the lake shore in the 50s. Wagner && .AVIATION... Issued 920 PM CDT Fri May 16 2025 Breezy wly winds are expected tnt-Sat in the wake of a strong cold front. MVFR Cigs will overspread srn WI from west to east late tnt then continue well into Sat afternoon. Areas of light rain and drizzle will occur at times especially from Madison and to the north and west of Madison. Gehring && .MARINE... Issued 920 PM CDT Fri May 16 2025 Low pressure near 29.2 inches over central Minnesota this evening will track across the Lake Superior/northern Lake Michigan region Saturday morning, then all the way to southern Quebec by late Saturday afternoon. The low will gradually weaken during this time, but breezy westerly winds are expected tonight into Saturday evening. Winds will then turn out of the northwest Saturday night, when high pressure around 30.0 inches will build into the Upper Mississippi River Valley and remain through the weekend. Gehring && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 7 PM Saturday. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSMilwaukee www.twitter.com/NWSMilwaukee www.youtube.com/NWSMilwaukee ####018008182#### FXUS65 KVEF 170223 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 722 PM PDT Fri May 16 2025 .SYNOPSIS...Warm temperatures will continue today with light afternoon breezes. A stray shower may develop along the Sierra crest this afternoon with gusty winds and sprinkles in the Owens Valley. A weather system will drop into the region over the weekend bringing gusty winds, cooler temperatures, and shower chances to mainly the Great Basin. Conditions will improve next week with warm conditions returning. && .UPDATE...Cloud cover associated with the shortwave will continue to stream through the area this evening, with a short break overnight before the next system arrives tomorrow. Winds will begin to increase out of the southwest in the morning and intensify through the day. The current Wind Advisories appear to be in good shape, though some high resolution models continue to suggest wind gusts over 40 mph reaching Owens Valley. Expect dry conditions to continue until tomorrow afternoon, when precipitation chances increase in the southern Great Basin. Totals should generally be light. && .SHORT TERM...Tonight through Sunday. An upper level system will dig into the region on Saturday which will bring increasing winds to the region. South to southwest winds increase in response to the increasing pressure gradient with impactful gusts over 40 MPH in the valleys and gusts up to 60 MPH in the terrain likely late Saturday morning through Saturday evening across San Bernardino, far southern Nevada, and Mohave counties. A wind advisory is in effect for these areas on Saturday where wind impacts with strong crosswinds, patchy blowing dust, difficult travel and boating conditions, and easily blown away light weight items are most likely. No changes were made to the wind headlines at this time, however a few places were considered: Looked at adding the Sierra slopes and Owens Valley to the Saturday wind Advisory as NBM 24hr Max Gust probabilities for over 40 MPH are 70%+. However, looking at the hourly data, probabilities are lower and isolated. Looked at downsloping set up down Sierra into the Owens Valley but it didnt look ideal and the stronger winds remained mostly in the high to mid slopes. There were some instances in hi- res models and ensemble members that did show higher gust 40 MPH+ in the Owens Valley, but it's very short lived. Held off on issuing any wind headlines for the Sierra and Owens Valley for now, it may still be needed but the stronger winds would likely be later in the day compared to the rest of the region so will continue to watch trends for a better signal and confidence increases. Also looked at the need to upgrade any of the Wind Advisory to a High Wind Warning, with the highest potential for this being in the Western Mojave Desert as well as on the lee side of the Spring Mountains. In the Western Mojave Desert, the low level jet briefly increases to 50-60 MPH between 5 PM to 11 PM Saturday evening. Forecast soundings show these winds struggling to make it to the surface as we decouple after sunset. There is an increase in probabilities for gusts over 58 MPH Saturday evening that matches up with the increasing low level jet, but the highest probabilities mainly focus on the terrain- valley areas show lower probabilities and only a brief uptick in the winds. For these reasons, did not upgrade to a High Wind Warning. On the lee-side of the Spring Mts, cross sections show a better potential for downsloping that in the Sierra, however it still is not great and models show max winds of 50-55MPH transitioning down the mountain. While these winds would be impactful as they would result in strong crosswinds over US-95 between Desert Rock and Indian Springs, winds should be sub-60 MPH and thus will continue with the wind advisory with wording that highlights this crosswind impact. Saturday night and Sunday, winds will become northwest as the main trough shifts east. A second piece of energy that rides down the anticyclonic side eof this trough and reinforce these winds Sunday afternoon. There continues to be model discrepancy about how strong this reinforcing shortwave will be and thus creates uncertainty in how strong the winds will be Sunday afternoon. Probabilities for wind gusts over 40 MPH are highest in northern Inyo County through Esmeralda and central Nye however it occurs Saturday night and is confined to the terrain. Winds are not as strong on Sunday, and while there is some potential for wind impacts Sunday afternoon is the stronger solution with the shortwave comes to fruition- the probability for widespread impacts Sunday afternoon is fairly low. The best chance would be in the Colorado River Valley as north winds will build waves and could impact boating. In addition to the winds, the systems this weekend may also bring precipitation to the Southern Great Basin area. The best chance will be Saturday afternoon when forcing is highest and weak instability is able to develop. PWATs will remain around 100%-150%, or about 0.50-0.75 inch, and low levels will struggle to saturate- so precipitation impacts will be low. There is a low probability (about 30%) for over 0.25 inches total of rain in Lincoln County, otherwise precipitation will remain light. Any thunderstorms that are able to develop could produce lightning and sudden gusty winds with dry low levels. On Sunday, there is a lingering risk for showers and isolated thunderstorms in eastern Lincoln and northern Mohave County, however the probabilities for rain are lower and more isolated than Saturday. Temperatures through the weekend will cool each day with each system. On Saturday, high temperatures will run about 3-5 degrees below normal, then about 5-8 degrees below normal on Sunday. .LONG TERM...Monday through Thursday. Ridging sets up over the region as the trough exits to the east. As this happens, temperatures will return to above average values. Las Vegas has a 63 percent probability of reaching its first 100 degree day on Thursday. By Thursday, expect widespread Moderate (Level 2) HeatRisk across the desert valleys, a level of heat that affects anyone sensitive to heat, especially those without adequate cooling or hydration. There is also the potential for some Major (Level 3) HeatRisk along the Colorado River, which affects anyone without effective cooling or hydration. Given the placement under high pressure, dry conditions and non-impactful winds are forecast through the long term. && .AVIATION...For Harry Reid...For the 00Z Forecast Package...Breezy south-southwest winds continue this afternoon with gusts around 20 knots. Winds remain southerly overnight though gusts should cease and speeds weaken. Strong south-southwest winds tomorrow as gusts reach 30-40 knots. SCT-BKN clouds at or above 15kft move in today and persist through tomorrow. For the rest of southern Nevada, northwest Arizona and southeast California...For the 00Z Forecast Package...Breezy south-southwest winds continue across most of the area this afternoon. Expecting gusts in the 15-25 knot range. As the sun sets, winds will weaken everywhere except DAG where they will remain breezy overnight. Stronger south-southwest winds forecast tomorrow, except at BIH where winds will be northwesterly. VFR conditions prevail throughout the TAF period with SCT-BKN clouds at or above 10kft. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ UPDATE...Meltzer SHORT TERM...Nickerson LONG TERM...Meltzer AVIATION...Woods For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter ####018005865#### FXUS61 KPBZ 170224 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1024 PM EDT Fri May 16 2025 .SYNOPSIS... There is potential for strong to severe storms tonight as a cold front approaches. Drier and cooler conditions return Sunday through early next week. && .NEAR TERM /UNTIL 8 AM SATURDAY MORNING/... KEY MESSAGES: - A decaying MCS is likely in the Ohio Valley tonight, but confidence in strength/location is low. ------------------------------------------------------------------- An ongoing MCS is pushing through southern Ohio. This will be the focus for another round of storms locally in the next couple of hours, however, confidence is low on how it evolves here. CAMs aren't too bullish on the MCS extending far enough north to reach much into SW PA as they mostly favor it along the best CAPE gradient around I-70 and south. This is the "most probable" solution at this point. Another possible, but lower confidence, solution is that development can extend farther north. This would be reliant on convection across the southern tip of Lake Michigan developing and congealing cold pools with the southern dominant MCS. This afternoon's storms have also left behind remnant outflow north of Pittsburgh, and this could act as a trigger for additional development. So, the CAMs still favor a southward sprint of the MCS as it gets into our eastern Ohio counties, and the best chances of severe tonight increasing the farther south of Pittsburgh you go. By the morning, convection should be out of the region resulting in a dry Saturday morning. && .SHORT TERM /8 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... KEY MESSAGES: - A cold front will cross the area, bringing gusty winds and a cooldown. ---------------------------------------------------------------- Irrespective of prior weather, there is high confidence of a cold frontal passage in the late morning and early afternoon. With this and the upper low pulling across the northern Great Lakes. This will pack the pressure gradient. Pre-frontally, there is some indication that there may be a shallow cap as a bit of pre-frontal warm advection rides up the axis of the front. Should this exist, winds will not start the day gusty. Should this be absent, gusts of 30-40 mph may develop in the morning. Into the afternoon, winds are expected to peak along the cold front. Gusts could be heightened in showers/storms along the front, mostly in the 40-50mph range, but the chance of severe could not be ruled out completely. After the cold front, low level cold-advection settles in, destabilizing profiles with the potential to mix into 40kt 850mb winds. Winds behind the front will be more likely than ahead of the front. With daytime gusts a bit higher in the ridges of eastern Tucker County, a wind advisory is in effect from 10am Saturday to 2am Sunday, where gusts up to 50mph are possible. Winds die down a bit overnight with decoupling && .LONG TERM /SUNDAY THROUGH FRIDAY/... KEY MESSAGES: - Cooler and drier pattern returns Sunday through Tuesday. - Precipitation chances return Tuesday into Wednesday with another low pressure system - Potential for heavy rain mid-week that warrants monitoring ------------------------------------------------------------------- Models have been consistent that troughing over the Great Lakes and northeast CONUS will maintain northwest flow over the local area Sunday into Monday, keeping temperatures seasonable and the weather dry through that time. Probability of precipitation increases again late Tuesday into Wednesday with a new low ejecting out of the Rockies and tracking east across the Plains. A few model scenarios note a stationary boundary straddling south of Pittsburgh with this passing low. If that scenario plays out, heavy rain could pose a threat for portions of the region around mid-week. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... The main impact to aviation tonight will be a line of thunderstorms advancing eastward across the area with a cold front. Restrictions, strong wind gusts, and possibly some hail could occur with some of the storms embedded in the line. The greatest uncertainty is the northern extent of this line. Capping with warmer air around 700mb across northern OH and NW PA should limit the storm potential across that region. Believe the latest CAMS are slightly too far south with this line, so the TAFs reflect this line advancing across OH, Wrn PA, and nrn WV. Did not include thunder at FKL and DUJ, though will monitor the convective trends. The line is likely to reach ZZV from 03-05Z, PIT 05-07Z, and LBE 06-08Z. Expecting a period of MVFR in showers behind this line. Conditions should improve by mid morning with mixing, though stratocu and scattered showers are expected through the day with a crossing upper trough. Mixing, cold advection, and a tight pressure gradient behind the front should result in gusty WSW wind from 25-35kt by mid morning, and continuing through the day. Outlook... Patchy cig restrictions are possible mainly N of PIT Saturday night into Sunday with the crossing trough and cool WSW flow. VFR returns Monday under high pressure, before restriction potential and showers return Tuesday and Wednesday with crossing low pressure. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...Wind Advisory from 10 AM Saturday to 2 AM EDT Sunday for WVZ514. && $$ SYNOPSIS...Cermak/Hefferan NEAR TERM...MLB/Lupo SHORT TERM...Milcarek LONG TERM...Cermak/Hefferan AVIATION...WM