####018004319#### FXUS63 KOAX 040910 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 410 AM CDT Sat May 4 2024 .KEY MESSAGES... - Cooler today and tomorrow, with highs in the 60s and dry weather expected. - There is a chance of severe thunderstorms (15 to 30 percent chance) Monday afternoon and evening. - Additional chances for showers and storms possible through the end of the week, but no organized threat for severe storms. && .DISCUSSION... Issued at 409 AM CDT Sat May 4 2024 Today and Tomorrow: Water vapor imagery this morning shows a modest troughing over the far north-central CONUS, with a shortwave extending southward, pivoting eastward through the largely zonal mid/upper flow that the base of the trough sits on. A recent surface analysis shows high pressure moving into northwestern Nebraska behind a cold front that has helped spark early morning convection moving to the southeast of the forecast area. KOAX radar imagery this morning features the continued departure of the MCS/bow that has brought widespread gusts of 35 to 45 mph, and has struggled to keep up with its own outflow. A cooler and drier airmass is set to move in behind this convection and make for a rather comfortable weekend, with highs in the low-to- mid 60s expected today before only slightly warmer highs settle in for Sunday in the upper 60s. Winds this afternoon will slowly diminish from the gusty northwesterly flow this morning and begin turning southeasterly in anticipation of a stronger storm system to kick off the work week. Monday and Beyond: The main focus of the forecast period comes Monday, when a high- amplitude and negatively-tilting trough pivots eastward from the Rockies, shooting a cutoff low northeastward just to the north of the forecast area. Robust forcing for ascent will be in full effect by the afternoon hours along a dryline, with convective initiation expected to occur in central Nebraska. By the time it reaches eastern Nebraska and western Iowa, a narrow corridor of surface- based CAPE ranging from 1000-2000 J/kg will provide ample instability to accompany 0-6 km bulk shear values of 40 to 50 kts or more to allow for an increased probability of severe storms (up to 30 percent for parts of southeast Nebraska. All hazards will be possible thanks to the favorable curvature in the low-level hodograph and combo of strong forcing/sufficient instability/strong shear, though will take the form of a line/cluster of storms. This activity is expected to quickly pivot through the forecast area Monday afternoon and evening, leaving the area dry by midnight as storms lift north and east. For Tuesday through the rest of the work week, we'll continue to be under the influence of the Monday system, which at this point will be occluded and cut off over the far northern High Plains. The main mid/upper level jet will be laid over the southeastern edge of the forecast area, keeping highs from rising much above the mid-to-low 70s with increasing chances for showers and storms returning for Thursday continuing into the weekend as the occluded system to the north finally gets slowly pulled away in the mid/upper flow. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1132 PM CDT Fri May 3 2024 The main concern of the TAF period continues to be the line of storms moving into eastern Nebraska over the next few hours. Those storms have already moved into the KOFK vicinity with lightning and rain, though ceilings and visibilities have yet to take a hit into MVFR or lower. Gusts as strong as 40 kts appear likely at KLNK when the line arrives around 0530 to 0600z, while areas north near KOMA see less intense storms with gusts as strong as 30 kts from 0645 to 0800z. Ceilings and visibilities are expected to take a hit behind the main line, with low-end MVFR ceilings and visibilities forecast through around or just after sunrise, with the area seeing clouds move out by late afternoon. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Petersen AVIATION...Petersen ####018005798#### FXUS65 KFGZ 040912 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 212 AM MST Sat May 4 2024 .SYNOPSIS...Warm and dry conditions are expected today with breezy afternoon winds. Winds will continue to increase, peaking on Sunday, and remaining gusty through much of the week. Isolated showers near the Arizona-Utah state line on Sunday with most areas remaining dry. Temperatures will cool slightly on Sunday but warm back up through midweek. Another trough will keep temperatures cool for the second half of the week but conditions will remain dry. && .DISCUSSION...Dry conditions will continue for today as we enjoy the warmth ahead of an approaching low pressure system. Southwest winds will be gusty again this afternoon with gusts between 25-35 mph. A deep upper level low will track towards the Pacific northwest and dig southward into the Great Basin late tonight into Sunday. As the low tracks into the Great Basin on Sunday, the pressure gradient will really start to tighten up. This will result in strong, gusty winds across the forecast area. Most areas will likely see gusts between 40-50 mph, but some localized gusts up to 65 mph will be possible, especially in areas downwind of the higher terrain. Some of the guidance has trended slightly downward with the strength of the winds but confidence is still high that we will see at least advisory level winds occur. However, with uncertainty as to how much coverage and the location of the highest winds, prefer to leave the High Wind Watch as is for now. As the low starts to cross to our north, we should also see an increase in moisture. While the majority of the moisture from this system will remain off to our north, there should be enough moisture moving into our region to squeeze out some showers across the Kaibab Plateau on Sunday and over the higher elevations of the Chuska Mountains. The majority of ensemble members are consistent with showing measurable precipitation over the Kaibab with a decent number of them showing measurable over the Chuskas. Most areas will remain dry as the low moves through and areas that do see some precipitation will likely see less than 0.10". Temperatures take a dip on Sunday, falling around 5-10 degrees below normal. With the strong winds and dry conditions, it will raise the potential for near critical fire weather concerns. The most likely areas will be across northeastern Arizona where RH values will drop below 15% during Sunday afternoon but with increasing moisture on Sunday it may be more marginal. The limiting factor may be the fuels but definitely something else to keep our eyes on. No changes to the current Fire Weather Watch at this time. As the low passes to the north and east, we should see better conditions return as zonal flow sets up through the week. Winds will remain breezy on Monday with cooler temperatures still hanging around the region. Temperatures will moderate remaining near or just below normal through the week as another trough may dip down from the north. Conditions look to remain dry at this time for the rest of the week but expect winds to continue to be gusty each day. && .AVIATION...Saturday 04/06Z through Sunday 05/06Z...Expect VFR conditions with scattered mid-level clouds. Light and variable wind overnight through most of Saturday morning. South-southwest winds gradually increasing after 17Z, reaching sustained speeds 15-20 kts gusting 25-30 kts during the afternoon and evening. OUTLOOK...Sunday 05/06Z through Tuesday 07/06Z...Mainly VFR conditions will persist but with increasing clouds late Saturday night into Sunday, along with a 10-30% chance of light rain or snow showers along/north of a KGCN-KRQE line Sunday afternoon and evening. Southwest winds 15-25 kts Saturday night, strengthening to 25-35 kts gusting to 40-55 kts on Sunday. Periods of MVFR visibility in blowing dust are likely from KINW-KSJN-KRQE northward for Sunday afternoon. Winds gradually decreasing Sunday night, with west winds 15-20 kts gusting 20-30 kts on Monday. && .FIRE WEATHER...Today and Sunday...Dry and mild conditions are expected today with increasing southwest winds. Anticipate gusts of 20 to 35 mph for this afternoon. Then, a Pacific storm will result in strong southwest winds on Sunday across northern Arizona. Expect sustained winds of 25 to 35 mph with peak gusts of 40 to 55 mph by late morning. Locations prone to downsloping winds will likely see gusts of up to 65 mph during this time. Minimum humidity for Sunday afternoon is forecast to be in the 10 to 20% range across northeast Arizona as the remainder of northern Arizona will be in the 25 to 30% range. Periods of critical fire weather conditions are likely across northeast Arizona with a Fire Weather Watch remaining in effect for locations near St. Johns in Apache County. Monday through Wednesday...West-southwest winds remain elevated each afternoon through Wednesday with widespread gusts of 25 to 35 mph. Average temperatures will continue through the period with afternoon humidity of 10 to 15% and overnight recoveries of 25 to 45%. No precipitation is expected through next week. && .FGZ WATCHES/WARNINGS/ADVISORIES... High Wind Watch from Sunday morning through Sunday evening for AZZ004>017-039-040. Fire Weather Watch from Sunday morning through Sunday evening for AZZ114. && $$ PUBLIC...Meola AVIATION...JJ FIRE WEATHER...LaGuardia For Northern Arizona weather information visit weather.gov/flagstaff ####018003834#### FXUS63 KABR 040912 AFDABR Area Forecast Discussion National Weather Service Aberdeen SD 412 AM CDT Sat May 4 2024 .KEY MESSAGES... - Dry conditions expected today and Sunday. Southeast to south winds begin to increase Sunday afternoon ahead of a Rocky Mountains low. - A much larger system looks to affect the region on Monday, with widespread moderate rainfall. The threat for severe weather still appears low at this time (higher across NE/KS/OK), but we will continue to monitor trends. && .SHORT TERM /TODAY THROUGH SUNDAY AFTERNOON/... Issued at 412 AM CDT Sat May 4 2024 High pressure builds into the region this morning bringing dry conditions. However, an upper trough is slow to depart so max Ts are expected to remain below normal by 5 to 10 degrees. Weak upper ridging builds in tonight. High pressure exits to the east on Sunday leaving a tightening pressure gradient between the high and a Rocky Mountains low. Winds increase out of the southeast to south Sunday afternoon with gusts across central SD up to 50 mph. Will likely need to hoist a wind advisory for some locations in the forecast area as we get closer to the onset. The upper ridge and good mixing will push temperatures up around 70 degrees on Sunday, as well. && .LONG TERM /SUNDAY EVENING THROUGH FRIDAY/... Issued at 412 AM CDT Sat May 4 2024 Sunday night we continue to see an upper level ridge over the area. This will continue into Monday morning. However, Monday afternoon, an upper level low starts to move into the region. This will stay in place through the day Saturday. This will bring a widespread chances of rain to the region through the day Thursday. Monday looks to have the highest rain totals for the long term, along with a chance for some storms. Consistent with what we saw yesterday, NAEFS is still showing PWAT values in the 97.5 percentile, starting west river and then spreading east across the rest of northeast SD through the day. For QPF, the NBM is still showing 50 to 65 percent probabilities for more than a half an inch in 24 hours ending Tuesday morning. Probabilities of more than an inch in 24 hours are still 30 percent or less. Although rain totals may exceed expectations under storms. While modles aren't showing a whole lot of CAPE (100-400 J/kg across the James valley, less elsewhere), Bulk shear values are between 35 and 50 kts across the region. This will sway the threat away from the hail side of things and more towards a wind threat, especially since we are already expecting stronger wind gusts. The Canadian model tries to bring back a chance for some storms on Wednesday, but other models disagree at the moment. PoPs start to decrease across the area Thursday evening. Speaking of winds, Sunday night into Tuesday morning is expected to be quite windy with gusts of over 40 mph possible. Sunday night, winds are fueled by a LLJ and Monday night, winds looks to be enhanced by strong CAA coming in from the west.Winds should start to die down Tuesday during the day. Temperatures in the long term still look to be right around to 10 degrees below average. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1220 AM CDT Sat May 4 2024 Terminals KABR,KATY,KPIR,KMBG VFR conditions are forecast throughout the TAF valid period at KPIR, KMBG and KABR. KATY could see a couple of hours of MVFR cigs and/or MVFR/IFR visbies in rain between now and 12Z. Beyond that, KATY should see prevailing conditions become VFR prior to 18Z. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ SHORT TERM...Wise LONG TERM...KK AVIATION...Wise ####018006510#### FXUS65 KREV 040913 AFDREV Area Forecast Discussion National Weather Service Reno NV 213 AM PDT Sat May 4 2024 .SYNOPSIS... Active weather returns today with a strong spring storm system bringing gusty to strong winds, valley rain, and mountain snow with conditions slowly improving Sunday. For next week, a slow warming trend with low chances for precipitation remains in the forecast. && .SHORT TERM Today-Sunday... IMPORTANT CHANGES: * Precipitation: There are no significant changes to the latest forecasted liquid totals, snowfall totals, timing, or snow levels for today's storm. Winter Storm Warnings for the eastern Sierra, and a Winter Weather Advisory for northeast CA remain in effect from 11 AM PDT today until 8 AM PDT Sunday. For more details, please visit Weather.gov/rev/winter. * Wind: There are also no major changes to the current wind forecast timing, locations, or strength for today. A High Wind Warning remains in effect from 8 AM PDT today until 8 PM PDT tonight for the Sierra Front southward through Lyon, Douglas, and Mineral counties. Elsewhere, Wind Advisories are still in effect for northern Washoe and the Surprise Valley until 5 PM PDT with Lake Wind Advisory for Lake Pyramid through 8 PM PDT. Please refer to the High Wind Warning as well as the Wind Advisories for more detailed information. KEY POINTS: * Precipitation: High resolution models and the HREF are indicating that the heaviest of the snowfall in the Sierra is still expected late morning into the early evening, with snowfall rates upwards 1- 2"/hr likely (>80%). Accumulations on roadways may be limited during the day given the time of year, but the snowfall rates may be enough to overcome this factor. Conditions in the Sierra will slowly improve overnight into Sunday morning, with minor snow showers possible during this time. However, one remaining concern is that cold overnight temperatures may lead to icy snowpacked roads in the Sierra, especially above 5,000 feet into Sunday morning. Most of the precipitation occurring in western NV will fall as rain through the afternoon. However, there is still a 20-40% chance for light snow showers for western NV later this evening into Sunday morning with little to no accumulation. * Wind: The HREF and guidance still indicate that strong winds throughout the region will materialize this morning and will continue into the evening. This may lead to travel disruptions due to strong cross winds, especially for any wind prone along US-395 from the greater Reno area all the way south into Mono County, as well as US-95 through the Hawthorne area. All area lakes will also experience strong winds creating unsafe conditions. * Temperatures: High temperatures by Sunday will fall to as much as 15-20 degrees below average for this time of year. In fact it will feel more like an average day for early February! A greater concern with the cold temperatures will be the overnight lows for Sunday and Monday mornings. Freezing temperatures of at least 32 degrees are looking likely (>60%) for most of western NV on Sunday morning. Lows for all Sierra communities will drop down into the upper teens to low 20s. * Sunday Leftovers: As the upper low pressure moves through the region on Sunday, precipitation will become more showery in nature and will mostly all be done by late morning. -McKellar .LONG TERM: Monday-Friday... Model guidance shows the upper air low opening up into more of a negatively tilted trough on Monday over the Rocky Mountains allowing for a mostly northwesterly flow over the CWA that continues through Tuesday. It also continues into Wednesday with the trough becoming more neutral over the central CONUS as a ridge moves over the Pacific Coast. As a result, temperatures look to rebound a bit though still being cooler on Monday before slightly cooling on Tuesday with a warming trend beginning on Wednesday. While the upper air pattern is unsettled at this time, signals do point to the warming trend continuing through Thursday and Friday. Precipitation chances look to be minimal at best currently during the next work week. There may be some fog concerns during the morning hours around the Truckee area during mornings to begin the work week, so will continue to monitor this potential. -078 && .AVIATION... Weekend Storm Update: A strong, unseasonably colder spring storm system is moving into the region today into early Sunday morning. * Snow/Rain: Widespread mountain snow showers and valley rains are likely (>70%) through tonight in northeast CA, the Sierra, and western NV. This colder airmass will allow for snow levels to drop to 5000-5500 feet the evening. Sierra terminals KTRK, KTVL, and KMMH could see between 3-5" of snowfall with a 80-90% chance for at least 2". However, high sun angle in May may limit accumulations on runways at those terminal during the day. There is also a slight chance for snow flurries tonight into Sunday morning for far western NV terminals (KRTS-KRNO-KCXP-KMEV). * Winds: Strong west to southwest winds will increase across the Sierra through tonight. Look for sustained ridgetop winds across the Sierra of 40-50kts with gusts upwards of 70-90kts during this time period. Expect periods of mountain wave turbulence, as well as LLWS for all area terminals. Strong west to southwest winds are possible for all western NV and Sierra terminals through tonight. -Amanda/McKellar && .REV Watches/Warnings/Advisories... NV...Wind Advisory from 8 AM this morning to 5 PM PDT this afternoon NVZ005. Winter Storm Warning from 11 AM this morning to 8 AM PDT Sunday NVZ002. High Wind Warning from 8 AM this morning to 8 PM PDT this evening NVZ001-003. Lake Wind Advisory from 8 AM this morning to 8 PM PDT this evening NVZ004. CA...Wind Advisory from 8 AM this morning to 5 PM PDT this afternoon CAZ070. Winter Weather Advisory from 11 AM this morning to 8 AM PDT Sunday CAZ071. Winter Storm Warning from 11 AM this morning to 8 AM PDT Sunday CAZ072-073. && $$