####018005552#### FXUS65 KTFX 031120 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 420 AM MDT Fri May 3 2024 UPDATED AVIATION SECTION .SYNOPSIS... One more cool and showery day is expected today before milder temperatures move in for the weekend. Another cool and wet Pacific weather system impacts North-central and Southwest Montana Sunday through at least mid next week, with the most significant precipitation and coolest temperatures expected Monday through Wednesday. && .DISCUSSION... The latest satellite and meso-analysis shows abundant cloud cover within a northwesterly flow aloft. Light snow showers have been ongoing all night, mostly over the northerly upslope areas adjacent to the Little Belt, Highwood, and Snowy Mountains. This shower activity will more or less persist through this afternoon with the continued northwesterly flow, though accumulation amounts will generally be negligible. Transient ridging builds in tonight for clearing skies with temperatures bottoming out in the 20s for most locations. Patchy fog development can be expected in spots, but shouldn't be a widespread problem. With one more day of ridging aloft, Saturday should be the driest day over next week while temperatures climb to near of slightly above average. Deep southerly flow aloft develops over Southwest MT Saturday night ahead of a closed low moving onto the Pacific NW coast. This system will trek eastward into S ID on Sunday, placing the Northern Rockies on the ascent side of the system for northward expansion of shower and isolated thunderstorm activity, though temperatures will remain near average for one more day. H700 flow slows down by Sunday afternoon and MU CAPE looks to be around 100 to 300 J/kg (highest southwest MT), so not expecting anything beyond general thunderstorm risks at this time. Ensembles remain in decent agreement with the aforementioned closed low swinging NE into E MT and slowing down some Monday through early Thursday. Although, there are differences on the precise path of the low, most favor cool, wet, and windy periods during this timeframe. According to the NAEFS Standardized Anomaly, H700 temperatures are forecast to be around -8C for much of this event, which would support mountain accumulating snow, but mostly rain at lower elevations. Current probabilistic forecasts for rainfall highlight the eastern portions of North-central MT with the highest chances (50 to 70%) for 1 inch of rainfall during the 72 hr period ending next Thursday at 6 am, with nearly all locations in the CWA standing at least a 50% for a quarter inch of rainfall for the same time period. The one drier exception looks to be southwestern valleys from Dillon to the Three Forks area. As mentioned earlier, thermodynamic profiles should confine accumulating snow to mountain areas, with the Little Belts and the Madison/Gallatin ranges seeing 60% + chances for 8 inches of snow or more Monday through Thursday, with most of it falling Tuesday night into Wednesday. H700 flow on the backside of this low will be at or above the 30 to 40 kt range for an extended period, resulting in gusty to at times strong northwesterly surface winds. While all days Monday through Wednesday look to be on the windier side, Tuesday is being singled out by the EC Extreme Forecast Index and NBM probabilistic forecasts as the windiest day overall, with many locations seeing 70% + chances for wind gusts above 40 mph. Drier and milder conditions move in for Thursday and Friday of next week, though around 50% of the ensembles support weaker troughing remaining in place for non-zero chances for precipitation and near average temperatures heading into next weekend. - RCG && .AVIATION... 520 AM MDT Fri May 3 2024 (03/12Z TAF Period) North Central (KCTB KHVR) and the plains of Central Montana (KGTF KLWT): Northerly upslope flow will continue widespread mountain-top obscuring low VFR/high MVFR ceilings through at least 15Z. However, lingering light snow along north-facing slopes (mainly east of KGTF into the KLWT area) will keep conditions there as IFR, obscuring those mountains. High pressure will start moving into the area from the west after 15Z, decreasing the snow and allowing broken ceilings to lift to at least low VFR levels with partial clearing starting after 18Z. However, weak instability during the afternoon may cause isolated to scattered light snow showers to form again between 19Z and 00Z, possibly causing periods of MVFR conditions. Southwest Montana (KBZN KEKS KWYS): VFR conditions are expected to continue through at least 04/12Z. Broken ceilings will continue through at least 18Z, then partial clearing is expected after 18Z. -Coulston Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 50 26 63 42 / 30 0 0 10 CTB 49 26 59 37 / 20 0 0 10 HLN 54 31 68 44 / 10 0 0 10 BZN 51 28 66 41 / 10 0 0 10 WYS 46 20 60 36 / 0 0 0 30 DLN 52 30 65 44 / 10 0 0 40 HVR 50 27 63 39 / 40 0 0 0 LWT 42 23 59 37 / 40 0 0 10 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls ####018005431#### FXUS65 KPSR 031121 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 421 AM MST Fri May 3 2024 .UPDATE...Updated Aviation Discussion... && .SYNOPSIS... Slightly above normal temperatures are expected today and tomorrow, with afternoon highs peaking in the low to mid 90s across the lower deserts. A dry weather system will traverse the Intermountain West this weekend leading to widespread breezy to windy conditions Saturday evening and Sunday, as well as cooler temperatures on Sunday and Monday. Dry weather will persist through next week, and temperatures are expected to rebound into the low 90s by Tuesday. && .DISCUSSION... Quasi-zonal flow currently exists over the Desert Southwest while the persistent troughing feature over the Intermountain West gradually begins to push east this morning. Though a weak upper ridge will traverse the Pacific Northwest later today and continue eastward, heights aloft will be relatively unchanged over the forecast area through tomorrow, and so afternoon high temperatures will be stable in the low to mid 90s across the lower deserts. The trough evident in current mid-lvl wv imagery off the Pacific Northwest Coast is expected to dive south along the West Coast Saturday, move inland, and traverse the Great Basin Sunday. The tightening pressure gradient ahead of and along the southern periphery of this trough will bring widespread breezy to windy conditions Saturday afternoon/evening and Sunday. A dry cold front associated associated with this system will also sweep through the CWA Sunday, leading to high temperatures dropping between 5-10 degrees across the lower deserts (and potentially more in the western deserts) on Sunday compared to their forecast values on Saturday. NBM guidance continues to show upwards of 80-90% probability for gusts to 40+ mph across Southwest Imperial County including the Imperial Valley Saturday afternoon/evening. As a result, Wind Advisories have been issued for portions of Imperial County late Saturday afternoon into the evening, with the Advisory over far southwestern Imperial County remaining in effect through Sunday afternoon. Global models depict 700 mb winds peaking around 40-50 kts early Sunday morning over Southeastern California, so the strongest winds aloft will not coincide with peak daytime heating that would allow higher momentum air to mix down to the surface. Thus, the strongest winds will be confined to high terrain locations overnight. Strong winds spread east across Arizona Sunday with afternoon gusts to 30-40 mph likely (>70%) across portions of South-Central Arizona. Additional wind headlines may be needed for portions of Imperial County on Sunday, as well as the high terrain zones of South-Central AZ within and around Southern Gila County. Dust channels may develop across dust prone areas as a result of the strong winds this weekend, which can reduce visibilities and make travel hazardous. Longwave troughing will continue to be reinforced over the Intermountain West through Monday which will also feature near to slightly below normal temperatures and continued daytime breeziness across the region. Heading into the middle of next week, temperatures look to slowly rebound to slightly above normal, however the overall longwave troughing pattern across the Western CONUS looks to persist. && .AVIATION...Updated at 1120Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: No aviation weather concerns under clear skies are expected through the TAF period. Wind pattern will continue to exhibit diurnal tendencies, with easterly winds this morning transitioning to a period of southerly winds through the early afternoon hours before a full transition out of the west. Wind speeds will generally remain aob 10 kts. Southeast California/Southwest Arizona including KIPL and KBLH: No aviation weather concerns under clear skies are expected through the TAF period. Winds will generally be southerly through the period at BLH aob 10 kts, while southeasterly winds at IPL are expected to become westerly during the evening hours. && .FIRE WEATHER... Warm and dry weather will persist into this weekend, with light and diurnal winds expected today. Afternoon highs will be slightly above normal today and tomorrow in the low to mid 90s across the lower deserts. A dry weather system will pass to the north of the region this weekend, leading to gusty winds, as well as cooler temperatures on Sunday and Monday. Winds could gust in excess of 40 mph across parts of SE California Saturday afternoon and evening and again Sunday morning/afternoon, while gusts climb to 30-40 mph across southcentral AZ on Sunday. Afternoon min RHs will bottom out around 10-20% over the next few days, while overnight recoveries remain in the poor to fair category between 30-60% for most areas. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...Wind Advisory from 3 PM Saturday to 5 PM PDT Sunday for CAZ562. Wind Advisory from 3 PM to 11 PM PDT Saturday for CAZ563-566-567. && $$ DISCUSSION...Whittock AVIATION...Young/Kuhlman FIRE WEATHER...Whittock/Smith ####018004607#### FXUS63 KMPX 031120 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 620 AM CDT Fri May 3 2024 .KEY MESSAGES... - Warmer and sunny today and Sunday with a chance for another round of rain on Saturday. - Unsettled weather pattern next week with more rain chances. && .DISCUSSION... Issued at 257 AM CDT Fri May 3 2024 Today through Sunday... High pressure today will provide for clear skies and plenty of sun during the day. These clear skies overnight have also allowed for temperatures to cool into the 40s. These cooler temperatures near the dew points have allowed for mist and fog to form. This is mainly occurring across far eastern Minnesota and into western Wisconsin. Once the sun rises and temperatures start to rise, this fog and mist will clear quickly. Tonight into Saturday morning, possibly into the afternoon in western Wisconsin, another round of rain showers is expected. As mentioned in the previous discussion this is tied to a shortwave aloft and its associated front at the surface. With the speed this is forecast to pass through and the moisture available up to around a quarter of an inch is expected. Not seeing much in the way of convection occurring with little instability and this matches up with the lack of general thunder in SPC Day 1 and Day 2 for us. With high pressure moving back in behind the front, clearing skies should arrive Saturday evening to Saturday night. Temperatures in the 60s for the sunny days today and Sunday with cooler temperatures in the upper 50s to lower 60s under cloudy skies on Saturday. Monday through Thursday... Monday will start with warm air advection warming us into the 70s. The high pressure should hang around long enough to keep most of Monday warm and dry, although some rain could start moving in later in the day across western Minnesota. This continues to look like a very unsettled period with a wide spread among the ensembles systems. Across this period from Monday night to Thursday each six hour block has at least a few members in the GEFS, ENS, or GEPS with QPF. This is spread across the period with one period having the highest confidence Monday night into Tuesday morning. Which matches when the deterministic models bring the main synoptic forcing through the Upper Midwest. This is related to amplified trough moving east of the Rockies during this period. As this system occludes and stalls out of the north central CONUS that PoP get less certain and lower. With this weaker and broader forcing there is much less confidence in where rain could occur. With the rain chances and clouds the rest of the week will be cooler with temperature more in the upper 50s to upper 60s rather than Monday's 70s. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 620 AM CDT Fri May 3 2024 VFR across all sites but EAU this morning. The fog at EAU will lift early in the period as the temperature begin to warm. After the fog lifts it will be a VFR day across all terminals. Rain will move from west to east across Minnesota and into Wisconsin this evening into Saturday morning. MVFR will be the main category as it rains. KMSP...VFR today and any fog this morning should remain in the river valleys rather than at the airfield. Cross wind wil continue this morning, but winds will remain light. Winds will increase later this morning, but the winds should shift to the west by that point. Rain chances increase tonight with MVFR expected. /OUTLOOK FOR KMSP/ SAT PM...VFR. Wind NW 5-10 kts. SUN...VFR. Wind variable 5 kts becoming SE 5-10 kts. MON...VFR. Chance PM MVFR/-RA. Wind SE 15-20G30 kts && .HYDROLOGY... Issued at 236 PM CDT Thu May 2 2024 The continued wet pattern for the next week will also continue to cause rising rivers over the entire HSA. Soils have started to become saturated at upper levels, so runoff is increasing with each rain event, though the onset of the growing season does help along with recovery days between rain events. All told, most tributaries and mainstem rivers will continue a slow rise for at least the next week, with some in the Minnesota and Crow river basins approaching minor flood stage by early next week (Minnesota at Morton already there). && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...NDC AVIATION...NDC HYDROLOGY...CCS ####018003217#### FXUS64 KTSA 031121 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 621 AM CDT Fri May 3 2024 ...New AVIATION... .SHORT TERM... (Today) Issued at 246 AM CDT Fri May 3 2024 Some strong to severe storms continue across the forecast area early this morning, mainly in the vicinity of a weak surface boundary. The stronger activity appears to be sustained by 0-3km bulk shear around 30kts despite somewhat limited instability. Storms will continue to move east southeast the rest of the overnight but will likely linger across SE OK and WC AR after 12z. Most of the area should remain dry today, but will maintain a low PoP in the afternoon for any lingering activity/isolated redevelopment after 18z. && .LONG TERM... (Tonight through Thursday) Issued at 246 AM CDT Fri May 3 2024 Additional storms will develop to the northwest later today along a another cold front that will move southeast into the area late tonight and into Saturday. Severe potential with this round of storms appears limited as activity begins to diminish Saturday afternoon. This boundary will stall to the south of the area late Saturday. Another round of storms will likely develop along the stalled boundary as an upper wave begins to move through the southern plains Saturday night. This activity will spread into the area late Saturday night and continue into Sunday. Storms should be out of the area by late in the day Sunday, and things should be quiet for the most part until later in the day Monday and Monday night. A strong upper system will lift through the mountain west region and into the high plains Monday evening, with storms expected to develop along the dry line to the west. These storms will track east with the highest chances for storms across NE OK and NW AR Monday night into Tuesday morning. For the rest of the forecast period, will continue with low PoPs across much of the area as weak disturbance traverse the area within strong mid level flow. && .AVIATION... (12Z TAFS) Issued at 618 AM CDT Fri May 3 2024 Convection will steadily wane across the region this morning with any remaining terminal impacts being short lived. Otherwise widely varying ceilings are likely through the morning with VFR, MVFR and periodic IFR levels likely. A trend toward rising ceilings and improving flight levels is expected by early afternoon. Low ceilings return overnight with thunderstorm chances increasing across NE OK terminals after midnight. && .PRELIMINARY POINT TEMPS/POPS... TUL 79 63 78 61 / 10 30 80 50 FSM 82 64 81 66 / 30 10 70 40 MLC 81 65 79 64 / 30 20 60 60 BVO 79 60 77 56 / 10 40 80 40 FYV 81 60 80 60 / 20 10 70 40 BYV 79 60 79 60 / 20 10 70 30 MKO 79 62 77 62 / 20 20 70 50 MIO 79 61 77 59 / 10 30 70 30 F10 79 62 78 62 / 20 20 80 60 HHW 79 65 79 64 / 40 20 60 60 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...23 LONG TERM....23 AVIATION...07 ####018005573#### FXUS65 KTFX 031121 CCA AFDTFX Area Forecast Discussion...CORRECTED TIME National Weather Service Great Falls MT 520 AM MDT Fri May 3 2024 UPDATED AVIATION SECTION .SYNOPSIS... One more cool and showery day is expected today before milder temperatures move in for the weekend. Another cool and wet Pacific weather system impacts North-central and Southwest Montana Sunday through at least mid next week, with the most significant precipitation and coolest temperatures expected Monday through Wednesday. && .DISCUSSION... The latest satellite and meso-analysis shows abundant cloud cover within a northwesterly flow aloft. Light snow showers have been ongoing all night, mostly over the northerly upslope areas adjacent to the Little Belt, Highwood, and Snowy Mountains. This shower activity will more or less persist through this afternoon with the continued northwesterly flow, though accumulation amounts will generally be negligible. Transient ridging builds in tonight for clearing skies with temperatures bottoming out in the 20s for most locations. Patchy fog development can be expected in spots, but shouldn't be a widespread problem. With one more day of ridging aloft, Saturday should be the driest day over next week while temperatures climb to near of slightly above average. Deep southerly flow aloft develops over Southwest MT Saturday night ahead of a closed low moving onto the Pacific NW coast. This system will trek eastward into S ID on Sunday, placing the Northern Rockies on the ascent side of the system for northward expansion of shower and isolated thunderstorm activity, though temperatures will remain near average for one more day. H700 flow slows down by Sunday afternoon and MU CAPE looks to be around 100 to 300 J/kg (highest southwest MT), so not expecting anything beyond general thunderstorm risks at this time. Ensembles remain in decent agreement with the aforementioned closed low swinging NE into E MT and slowing down some Monday through early Thursday. Although, there are differences on the precise path of the low, most favor cool, wet, and windy periods during this timeframe. According to the NAEFS Standardized Anomaly, H700 temperatures are forecast to be around -8C for much of this event, which would support mountain accumulating snow, but mostly rain at lower elevations. Current probabilistic forecasts for rainfall highlight the eastern portions of North-central MT with the highest chances (50 to 70%) for 1 inch of rainfall during the 72 hr period ending next Thursday at 6 am, with nearly all locations in the CWA standing at least a 50% for a quarter inch of rainfall for the same time period. The one drier exception looks to be southwestern valleys from Dillon to the Three Forks area. As mentioned earlier, thermodynamic profiles should confine accumulating snow to mountain areas, with the Little Belts and the Madison/Gallatin ranges seeing 60% + chances for 8 inches of snow or more Monday through Thursday, with most of it falling Tuesday night into Wednesday. H700 flow on the backside of this low will be at or above the 30 to 40 kt range for an extended period, resulting in gusty to at times strong northwesterly surface winds. While all days Monday through Wednesday look to be on the windier side, Tuesday is being singled out by the EC Extreme Forecast Index and NBM probabilistic forecasts as the windiest day overall, with many locations seeing 70% + chances for wind gusts above 40 mph. Drier and milder conditions move in for Thursday and Friday of next week, though around 50% of the ensembles support weaker troughing remaining in place for non-zero chances for precipitation and near average temperatures heading into next weekend. - RCG && .AVIATION... 520 AM MDT Fri May 3 2024 (03/12Z TAF Period) North Central (KCTB KHVR) and the plains of Central Montana (KGTF KLWT): Northerly upslope flow will continue widespread mountain-top obscuring low VFR/high MVFR ceilings through at least 15Z. However, lingering light snow along north-facing slopes (mainly east of KGTF into the KLWT area) will keep conditions there as IFR, obscuring those mountains. High pressure will start moving into the area from the west after 15Z, decreasing the snow and allowing broken ceilings to lift to at least low VFR levels with partial clearing starting after 18Z. However, weak instability during the afternoon may cause isolated to scattered light snow showers to form again between 19Z and 00Z, possibly causing periods of MVFR conditions. Southwest Montana (KBZN KEKS KWYS): VFR conditions are expected to continue through at least 04/12Z. Broken ceilings will continue through at least 18Z, then partial clearing is expected after 18Z. -Coulston Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 50 26 63 42 / 30 0 0 10 CTB 49 26 59 37 / 20 0 0 10 HLN 54 31 68 44 / 10 0 0 10 BZN 51 28 66 41 / 10 0 0 10 WYS 46 20 60 36 / 0 0 0 30 DLN 52 30 65 44 / 10 0 0 40 HVR 50 27 63 39 / 40 0 0 0 LWT 42 23 59 37 / 40 0 0 10 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls ####018007921#### FXUS66 KLOX 031122 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 422 AM PDT Fri May 3 2024 .SYNOPSIS...03/327 AM. A dry weather will continue through early Saturday morning, then an unseasonably cold storm system will brush the area to the north this weekend with a chance for light precipitation later Saturday into Sunday. Increasing onshore flow ahead of the storm will bring a cooling trend through Sunday. Night and morning low clouds and fog will struggle to clear at the coast today, then spread back inland tonight. A warming and drying trend will develop next week. && .SHORT TERM (TDY-SUN)...03/420 AM. The latest fog product imagery shows low clouds and fog becoming more entrenched across the region, extending well into the Southland valleys and touching the foothills. Clouds are little less extensive north of Point Conception, but clouds will likely continue to fill in later this morning across much of the coastal and valley areas. Cooling is set up to continue today as strengthening onshore flow out ahead of an unseasonably cold storm system will bring a deeper marine intrusion. The low cloud field will push well into the coastal slopes tonight and reach into the portions of the interior valleys north of Point Conception. The stronger onshore flow and the tightening pressure gradient out ahead of the storm's cold front will bring increasing southwesterly winds across the interior portions of the area through Saturday night. Winds should remain below advisory levels this afternoon and evening, but a wind advisory will likely be needed for the Antelope Valley and adjacent foothills on Saturday afternoon and night as the gradient tightens further. The storm system, over the Gulf of Alaska this morning, will dig south into northern California through Saturday night, brushing the area to the north. A cold frontal boundary will drop south into the region on Saturday, bringing rain to much of the area. PoPs have been nudged higher in the latest forecast, going higher than NBM solutions. All of the ensemble members have light precipitation developing for areas north of Point Conception, along the northern slopes of the mountains, and across eastern Los Angeles County. The forecast is little more questionable for southern Santa Barbara County, Ventura County, and western Los Angeles County. The forecast trends wetter as deterministic solutions are starting to trend more southwest to west with the low-level flow pattern. The forecast trends more toward the deterministic solutions south of Point Conception, buying into the model trends. Model tabular forecast output suggests a high- to-likely chance of rain for areas north of Point Conception, and moderate-to-high chance for areas southwest of Point Conception. There is a moderate chance that southern Santa Barbara County, Ventura County, and western Los Angeles County could end up being in a rain shadow effect as downsloping occurs from the Transverse Ranges. Rainfall amounts will likely range from a quarter inch or less, except a quarter to half inch across northwestern San Luis Obispo County. Amounts will be highest for the northern portion of the area and along the northern slopes of the mountains. Rainfall will only amount to a few hundredths at most for most coastal and valley areas south of Point Conception. Gusty west to northwest winds will develop across many coastal areas, into the Santa Ynez Valley, across southern Santa Barbara, up into the Interstate 5 Corridor, and down into the Antelope Valley. EPS solutions indicate good agreement across the area for the potential for wind advisory, but a handful of solutions indicate a gust potential over 55 mph at KSDB. This will need to be monitored as we get closer as wind gusts have been trending generally higher with each run. A colder air mass will spread into the area between Saturday and Sunday night with the cold front. Temperatures during this stretch trend colder than NBM values, and Sunday could be a cold day for May, similar to a February or March with 60s being common across the coastal and valley areas. .LONG TERM (MON-THU)...03/415 AM. A warming and drying trend will develop for the work week next week as high pressure aloft reestablishes. The forecast ensembles agree with a warming trend extending through at least Thursday. EPS solutions tend to hold onto the warming trend extending into next weekend. EPS cloud cover means point to the marine layer depth being kept in check, but confidence is moderate at best in this solution as we are in May. The latest forecast keeps some marine layer induced low clouds and clouds returning to coastal areas by mid week. && .AVIATION...03/0316Z. At 2327Z at KLAX, the marine layer was 2000 ft deep with an inversion top at 4900 ft and a temperature of 16 C. High confidence in desert TAFs moderate confidence elsewhere. Timing of flight cat changes could be off by +/- 2 hours. There is a 20% chance of LIFR conditions at KSMX and KSBA. There is a 20% chance for brief cigs at KPRB. KLAX...Moderate confidence in TAF. Timing of flight cat changes could be off by +/- 2 hours. Cigs could arrive as low as BKN008 and will lift through the period. An east wind component of around 5 kt is possible 09Z-15Z Fri, but will likely remain below 10 kt. KBUR...Moderate confidence in the 00Z TAF. Timing of flight cat changes could be off by +/- 2 hours, with a 30% chance of cigs will arrive as early as 07Z tonight. && .MARINE...02/919 PM. In the outer waters, Small Craft Advisory (SCA) level winds are expected to increase to Gales (70% chance) this afternoon, with the strongest winds off the coast. Gales will continue thru late tonight, then drop to SCA levels. Winds may even drop below SCA level for a while Sat morning, but seas will remain above SCA levels. SCA level winds are expected (80% chance) Sat afternoon, then continue much of the time thru Tue. There is a 50% chance of Gale force winds Sun afternoon/evening, then a 30-40% chance during the afternoon/eve hours Mon thru Tue. In the inner waters N of Pt. Sal, SCA level winds will develop today, then continue thru late tonight. There is a 40-50% chance of SCA level winds/seas during the afternoon/eve hours Sat, then SCA winds are likely (70% chance) during the afternoon/eve hours Sun thru Tue. There is a 30% chance of gales Sun afternoon/eve. In the SBA Channel, there is a 40% chance of SCA level winds in western portions of the channel this afternoon thru late tonight, then Sat afternoon/eve. SCA level W-NW winds are expected Sat night thru late Sun night (80% chance), and are likely (60-70% chance) during the late afternoon thru late night hours Mon thru Tue. There is a 30% chance of gales Sun afternoon/eve. In the southern inner waters, there is a 30% chance of SCA level winds from Anacapa Island to Malibu during the late afternoon/eve hours Sat. SCA level winds are likely (70% chance) Sat night thru late Sun night. There is a 40% chance of SCA level winds during the late afternoon thru late evening hours Mon thru Tue. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect until 3 AM PDT Saturday for zone 645. (See LAXMWWLOX). Gale Warning in effect until 3 AM PDT Saturday for zones 670-673-676. (See LAXMWWLOX). && $$ PUBLIC...Hall AVIATION...Phillips MARINE...DB SYNOPSIS...Hall weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox ####018004508#### FXUS63 KICT 031122 AFDICT Area Forecast Discussion National Weather Service Wichita KS 622 AM CDT Fri May 3 2024 .KEY MESSAGES... - Storms likely tonight into early Saturday with some strong to severe storms possible tonight, especially across portions of central KS. - Showers and a few storms return late Saturday night into early Sunday across southern and southeast KS. - Increasing threat of severe weather on Monday evening and Monday night. && .DISCUSSION... Issued at 138 AM CDT Fri May 3 2024 Water vapor satellite imagery and RAP analysis continue to show a robust mid/upper trough along the Canadian border over the Northern Plains/Saskatchewan-Manitoba region moving northeastward while another progressive shortwave trough was digging across the Northern Rockies. Meanwhile, a cold front was draped over the Middle Mississippi Valley area and points southwestward into the Southern Plains. A stable post-frontal regime is firmly entrenched across the forecast area today leading to quite weather conditions for the daytime hours. Seasonably mild conditions are anticipated with relatively light winds and highs in the 70s. For tonight, the shortwave trough over the Northern Rockies will sweep eastward driving another cold front southward across the Central Plains. This front will provide a focus for showers and thunderstorms tonight. Elevated CAPE and steep mid-lvl lapse rates should support some strong to severe storms, especially across our central KS counties this evening where damaging winds and marginally severe hail will be possible. Uncertainty grows further south and east as we move through the overnight hours with waning elevated CAPE and a weakening LLJ progged. Some remnant shower and storm activity could linger early in the day on Saturday across southern KS but the focus is expected to shift south and east of the area on Saturday afternoon as a stable post- frontal regime materializes across the area. Seasonably cool temperatures are anticipated with highs ranging from the mid 60s in central KS to the lower 70s in southeast KS. Another shortwave trough lifting out of the Southern Rockies and over the Southern Plains could bring an increasing chance for showers and storms late Saturday night into Sunday morning but there remains some uncertainty in how far north it will track with higher probabilities remaining across far southern and southeast KS. The threat for strong or severe storms is expected to remain south of the area with this system but a further north track could result in better moisture return and the potential for more robust deep moist convection. As we move into early next week, a vigorous mid/upper trough is progged to move into the Rockies before emerging negatively tilted over the Central Plains late on Monday. Conditions continue to look favorable for a more widespread severe weather event on Monday afternoon and Monday evening across the Central Plains. The EPS/GEFS continue to advertise a vigorous upper jet nosing into Kansas late Monday where high quality moisture is progged in the warm sector. It is looking like a synoptically evident event unfolding where significant severe weather may unfold including supercells with very large hail, damaging winds and tornadoes. Tue-Thu...Drier air will overspread the region in the wake of the Pacific front on Tue with dry weather and mild conditions expected with highs in the 80s. Heights/thickness are progged to lower as we move into the middle of the week with a vigorous and slow moving trough progged to camp over the Northern Plains. This is expected to result in mostly dry weather with seasonable temperatures in the 70s for most areas on Wed-Thu. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 619 AM CDT Fri May 3 2024 Low clouds(MVFR category) will linger over southern Kansas this morning and into the afternoon before scattering out. Meanwhile southeast winds will increase over central Kansas later this morning and afternoon. A line of showers and storms is expected to move eastward across the region late tonight. A few of the storms could reach severe limits over central Kansas. && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...MWM AVIATION...CDJ ####018006586#### FXUS63 KLOT 031122 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 622 AM CDT Fri May 3 2024 .KEY MESSAGES... - Increasing chances of showers and thunderstorms capable of producing gusty winds Saturday afternoon and evening. - Periodic shower and thunderstorm chances next week, with some potential for strong to severe storms Tuesday. && .DISCUSSION... Issued at 335 AM CDT Fri May 3 2024 Through Saturday: Ongoing convective activity across portions of northern Illinois and northwest Indiana continues to wane early this morning as remaining instability and associated mid-level lapse rates decrease. In fact, as of 3am CT, very little lightning has been observed in the forecast area over the past hour. While a few lightning strikes are still possible through sunrise, a departing mid-level wave will limit remaining deeper-layer support. Meanwhile, a cold front roughly parallel to the Mississippi River will continue to shift a band of shallow showers across the area into mid-morning. High pressure will quickly settle across the western Great Lakes through tonight. The combination of a rather dry airmass evident by upstream dew points generally in the 30s along with fairly clear skies today should allow seasonably warm conditions in the 60s along the shore and lower 70s inland today. Today's cold front will stall across the south half of Illinois, allowing for a return of low-level moisture behind the surface high on Saturday. A small mid-level wave lifting northeast across the far Upper Mississippi River Valley Saturday morning may brush the northwest CWA. Return of sufficient moisture by this point remains in question, though an isolated storm cannot be ruled out for areas west of I-39 late morning into early afternoon. A disjointed trough passage into the western Great Lakes later Saturday and into Saturday night should better align with increasing shallow moisture to produce scattered showers and storms as far east as around I-57 by sunset. However, fairly shallow low-level moisture return and a deep reservoir of dry mid-level air may limit storm coverage but also support gusty winds with any convection. Kluber Saturday Night through Thursday: Showers and thunderstorms should be ongoing along and ahead of a cold front Saturday evening. Some of these storms could be strong to severe early in the evening, with mainly localized gusty winds, though this threat should diminish with eastward extent due to diurnal loss of low-level instability and generally weak deep-layer shear. Sunday through Sunday night looks to be largely dry and cooler, as Saturday night's cold front settles toward the Ohio Valley and surface high pressure builds east across the upper Midwest and western Great Lakes region. Temperatures will be limited to the lower 70s well inland Sunday afternoon, while northeast winds off of Lake Michigan will keep highs only in the upper 50s near the lake. Lows will dip into the mid-upper 40s in most spots Sunday night. Ensemble guidance depicts deep upper level trough developing across the western and central CONUS heading into next week, with a closed upper low developing across the Northern Plains Monday. A series of mid-level short waves are progged to rotate around the south and southeast periphery of the circulation as it slowly drifts east, eventually lifting the front across the lower Ohio Valley northward as a warm front later Monday night into Tuesday. Some spotty elevated showers are possible as early as Monday afternoon and evening as warm/moist advection develops atop the warm frontal slope, though really becomes more focused into the local area Tuesday into Tuesday night. This appears to be the period with the greatest potential for thunderstorms, some potentially strong to severe given strong mid-level wind fields and warm/moist/conditionally unstable low levels. Temperatures looks to surge back into the upper 70s/around 80 Tuesday afternoon, with surface dew points rising into the 60s as the warm front lifts across the area. Periodic shower and thunderstorm chances linger through the mid-week period, as ensembles continue to indicate the upper trough drifting east across the upper Midwest/Great Lakes region through the end of the forecast period. Blended NBM guidance maintains chance pops both Wednesday and Thursday, especially during the more diurnally-favored afternoon/evening hours. Higher low-level Theta-E air mass gradually gets shunted east of the area during this time, with temperatures gradually settling into the lower 70s by Thursday. Ratzer && .AVIATION /12Z TAFS THROUGH 18Z SATURDAY/... Issued at 612 AM CDT Fri May 3 2024 Key Aviation Messages... - Period of low-MVFR and IFR ceilings early this morning, scattering to VFR by mid-morning. - North-Northwest winds 10-15 kts early, becoming northeast around 10 kt late morning/midday. - Low-confidence potential for MVFR ceilings at KMDW/KORD early Saturday morning. Surface cold front was pushing through northeast IL early this morning. A fairly narrow band of low-MVFR and patchy IFR ceilingswas along/behind the front, and will affect the Chicago terminals for a few hours this morning before moving east and allowing VFR conditions to prevail. A few spotty sprinkles may linger for an hour or so, though no impactful showers are expected. With the front, winds shift north- northwest 10-15 kts, and these will persist through late morning before winds veer northeast at around 10 kts. High-res model guidance has shown quite a bit of spread as to just when the shift to northeast will occur, but should occur in the late morning to midday time frame. Winds will then remain northeast through this evening, eventually becoming light east late tonight and southeast Saturday morning. Guidance continues to suggest some low-MVFR stratus may form over Lake Michigan and northern Indiana early Saturday morning, and could possibly spread west into KMDW/KORD around sunrise. Confidence is low at this distance, but will continue to monitor with later forecasts. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago ####018007236#### FXUS66 KOTX 031123 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 423 AM PDT Fri May 3 2024 .SYNOPSIS... The region will see mild and dry conditions today, with the exception of a few scattered showers near the Canadian border. The next system will move into the region Friday night, expanding eastward through Saturday. Sunday will be cool and wet, with additional unsettled weather expected early next week. && .DISCUSSION... Today through Saturday Night...As you wake up this morning and head to work, you may notice that temperatures feel warmer than they have the last few mornings. Well you're not imagining things, the temperatures are 5 to 10 degrees warmer at 2am than they were 24 hours ago. Clear skies this morning will see clouds increasing ahead of the next system. There will be some isolated showers in far northeastern Washington and ID Panhandle this afternoon, mainly along the Canadian border. Winds will pick up along the lee side of the Cascades, especially in the Okanogan Valley and Waterville Plateau as the winds shift southerly with gusts of 35 to 40 mph. Winds will decrease in the Okanogan Valley overnight but gusts of 30 mph remaining in the Waterville Plateau. Temperatures will rise slightly, reaching the mid 60s with a few 70s in the LC Valley. Rain will move in overnight over the Cascades, which will be the beginning of a pattern change. Lows will be even warmer tonight but closer to normal, only dropping into the 40s. Saturday's front will chug slowly eastward as the low slides towards the Oregon coast. Morning temperatures will warm throughout the day, with Saturday being the warmest of the forecast for locations along and east of the Columbia Basin. Even with the additional cloud cover, prefrontal warming will warm above the temperatures seen today. The front will move through lee side of the Cascades in late morning, keeping high temperatures in the 50s and rain showers arriving earlier. Rain showers will continue to spread eastward throughout the day. Breezy winds will continue through the day, expanding into the upper Columbia Basin and Palouse with gusts to of 25 to 30 mph. By late Saturday evening, much of the region will have some sort of showers in their area. These showers will increase throughout the night, bringing some beneficial rainfall to the region. /KM Sunday and Sunday night: Wet and cool. As a closed upper low tracks across Oregon into southern ID, a deformation band slowly pivots across the Inland NW giving way to round of rain. Precipitable waters increase to over 0.8” across eastern WA by Sunday morning. - Precipitation: Moderate rain amounts of are expected especially across parts of the Columbia Basin, southeast WA and the southern ID Panhandle where the best dynamics and moisture will lie. Storm total rainfall amounts are expected to rain from less than a tenth of an inch in north-central WA to a half to near an inch of rain across southeast WA where stream flows are running low. Snow levels should be high, spanning from 5-6 K ft with mainly the higher elevations experiencing snow in the central Cascades, central ID Panhandle, and Blue mountains. The precipitation will lead to small rises on area rivers and streams although no flooding is expected yet any intense rain rates may lead to ponding of water in low lying areas. Overall anticipate the rain to be beneficial after the latest stretch of dry weather. -Temperatures: Daytime highs will be vary depending on where the steady rain lies. Right now it will remain cooler from the eastern Columbia Basin to the Spokane/ Coeur d’Alene area and Palouse as they struggle to reach 50, meanwhile temperatures will be nearing 60 in north central WA further from rain bands. Westerly winds gradually increase by the afternoon to evening hours especially across southeast WA in the lee of the Cascades with gusts 25 to 35 mph as the low level boundary shifts east and pushes across north ID by Sunday evening. Monday through Tuesday: Breezy and showery. A west to northwest flow aloft prevails in the wake of the departing low, while a secondary weak trough rotates in from the Pacific. Low level moisture remains and showers will be more numerous by Monday afternoon as instability increases slightly. With mean capes near 100 J/kg across northeast WA into the ID Panhandle, this supports the mention of thunderstorms for Monday afternoon and evening. Breezy westerly winds continue with peak gusts in the afternoon and evening hours of 25 to 30 mph especially across the Columbia Basin and Palouse Monday afternoon. Slight chances anticipated for Tuesday with mainly less moisture and less shower coverage. The risk of thunderstorms will be less and confined over northeast WA. Westerly winds continue although less gusty topping out at 20 to 25 mph. Anticipate more seasonal temperatures with highs in the 50s to lower 60s and overnight lows in the mid 30s to lower 40s. Wednesday through Friday: Drier and warmer. An upper level ridge builds over the eastern Pacific and builds inland. The threat of showers lingers over north Idaho and brushing extreme eastern WA for Wednesday, but trending less coverage for Thursday as drier and more stable conditions arrive. Under lighter winds, the more noticeable change will be warmer temperatures reaching the 60s to lower 70s on Thursday and in the 70s by Friday. The dry and warm pattern looks to continue into the following weekend. /rfox. && .AVIATION... 12Z TAFS: VFR conditions will prevail. Afternoon showers will form near the Canadian border. Mid clouds will move into the region late Friday as the next system moves in. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: There is high confidence in VFR conditions. ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance For additional probabilistic information for NWS Spokane airports, please refer to the Aviation Dashboard on our webpage: https://www.weather.gov/otx/avndashboard && .PRELIMINARY POINT TEMPS/POPS... Spokane 65 45 68 42 48 40 / 0 0 10 40 80 70 Coeur d'Alene 65 42 67 42 47 40 / 0 0 10 30 60 80 Pullman 63 46 66 38 44 39 / 0 0 20 70 80 80 Lewiston 71 47 71 45 53 44 / 0 0 10 70 80 80 Colville 65 40 68 43 56 38 / 10 0 20 30 80 80 Sandpoint 62 42 65 46 51 41 / 10 0 10 30 60 90 Kellogg 62 43 65 44 46 40 / 10 0 10 40 80 90 Moses Lake 71 52 70 45 55 42 / 0 10 40 50 80 20 Wenatchee 68 52 60 47 58 44 / 0 20 70 50 40 10 Omak 70 49 68 49 63 42 / 0 10 30 40 40 30 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$ ####018003910#### FXUS63 KUNR 031124 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 524 AM MDT Fri May 3 2024 .KEY MESSAGES... - Cool with showers today. Minor snow accumulations possible in the Black Hills. - Warmer and windy this weekend - Strong Storm system early next week with potential for several hazards; severe thunderstorms Monday, locally heavy rain Monday/Tuesday (northeastern Wyoming/northwestern South Dakota), high winds Tuesday/Wednesday, snow for the Black Hills Tuesday/Wednesday. && .DISCUSSION...(Today Through Thursday) Issued at 240 AM MDT Fri May 3 2024 Current surface map places low across northwestern Minnesota with cold front across eastern South Dakota into northern Nebraska. Water vapor shows shortwave over eastern Montana and another over southern Idaho. The pair of shortwaves track eastward today. Best lift occurs later this morning through early evening over southern half of the forecast area along low level baroclinic zone. Thermal profiles support snow in the Black Hills. High resolution models point to accumulating snow for the higher elevations with HREF mean around 3" (10:1 SLR) and the 25th-75th percentile is 1"-5". Given expected snowfall rates (<0.5"/hour) and time of day, SLR's should be 25-50% lower. That still gives an inch or two of snow accumulation which should mainly be limited to grassy/elevated surfaces. Surface high drops across the area early Saturday with dry weather expected. As the high shifts east during the day southerly flow increases. Shortwave ridge aloft crosses the area early Sunday as deep low tracks through the Great Basin. Tight pressure gradient will result in windy conditions Sunday. Highs warm into the 60s for Saturday and 70s on Sunday. Upper low swings through the Rockies into the Northern Plains Monday with low stalling out over Dakotas Tuesday. Low then slowly drifts southeast on Wednesday. Decent agreement with deterministic GFS/ECMWF/GEM, through there are some minor differences in the details. Chance of showers/thunderstorms increase late Sunday/Sunday night with an uptick in buoyancy/theta-e advection on nose of low level jet. Looks to be widespread showers/thunderstorms Monday as robust QG forcing lifts through the area. Timing of best lift/buoyancy/shear could result in a threat of severe thunderstorms Monday afternoon. Focus for widespread rains will come as TROWAL wraps around the upper low Monday night through Wednesday. At this time, the heaviest rains appear to be north/northwest of the forecast area, though the LREF paints 40-50% probability of >1.50" QPF for parts of northeastern Wyoming into the northern Black Hills and northwestern South Dakota. Even with the potential for locally heavy rain, threat of any flooding is very low. Biggest issue with the storm will be very strong west-northwest winds. Will likely see gusts of 50-60 mph, especially on the plains north and east of the Black Hills. Thermal profiles marginally cold enough that there could be some snow in the northern Black Hills Tuesday/Wednesday. However there is a wide spread in low level temperatures resulting in low confidence in any snowfall amounts. LREF has small area in the higher elevations with 30-60% probability of >6". && .AVIATION...(For the 12Z TAFS Through 12Z Saturday Morning) Issued At 522 AM MDT Fri May 3 2024 MVFR/local IFR conditions expected in rain/snow today, across parts of northeastern WY and SW to south central SD. Conditions will gradually improve to VFR from west to east this evening. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...7 AVIATION...Pojorlie