####018006921#### FXUS66 KMTR 032016 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 116 PM PDT Fri May 3 2024 ...New SYNOPSIS, SHORT TERM, LONG TERM... .SYNOPSIS... Issued at 1237 PM PDT Fri May 3 2024 Cold front on track to bring widespread rain, cooler temperatures, and gusty winds this weekend. Dry weather returns Sunday with a gradual warming trend through next week. && .SHORT TERM... (This evening through Saturday) Issued at 1237 PM PDT Fri May 3 2024 Mostly clear skies over the region today ahead of the next cold front. Ample cloud cover associated with the front now moving into the northern portions of the state will continue to move southward through tonight. Areas of light rainfall are expected to begin early Saturday morning along favored west-facing upslope areas in the coastal ranges as moist low-level westerly flow increases ahead of the front. Much of the surface front should be through the Bay Area by mid-morning, and late morning for areas further south along the Central Coast. Aided by a robust 150 kt NW-SE oriented jet on the back side of the low, this will be a rather quick-moving front with little-to-no chance of stalling. However, this jet and continued support of an enhanced northwesterly Eastern Pacific jet along the West Coast will support gusty northwest winds to 25-35 mph along coastal areas and NW-SE oriented valleys through the weekend. Rainfall amounts Saturday will be in the ball park of 0.4-0.75" for most locations, with a few seeing upwards of 1-1.25" in the coastal ranges of the North Bay and the Santa Cruz Mtns. Behind the cold front Saturday afternoon and evening, there is a slight chance for isolated thunderstorms across the area. Scattered showers will persist into Saturday evening, but conditions appear favorable for a few locally strong updrafts that would support a rumble of thunder or two, as well as small hail. Deep convection would not be supported, given limited cooling aloft, promoting a more stable environment aloft. Thus, any storms that do develop would be relatively short-lived. Really nothing out of the ordinary for us during these typical cold core systems, just more resemblant of a system we'd see in January rather than May. && .LONG TERM... (Sunday through next Thursday) Issued at 1237 PM PDT Fri May 3 2024 Sunday looks to be on the drier side with the low departing. Temperatures the next few days will be on the cool side with afternoon high temps dropping by as much as 18 degrees for inland locations. Low temps Sunday morning will be in the 40s for most, with a few pockets of upper 30s for inland and high elevation areas. Otherwise, a warm up is on tap for the rest of next week as the pattern becomes more ridge-dominant. By Wednesday, expect afternoon highs in the 70s to near 80, and the mid-to-upper 60s along the coast. && .AVIATION... (18Z TAFS) Issued at 1126 AM PDT Fri May 3 2024 VFR prevails through the daytime today, though stratus makes a return in the early to mid evening for most terminals, bringing largely IFR/LIFR conditions as ridging continues to squash cloud decks. Winds generally W/NW and strong today, with gusts around 20- 25 knots, higher at SFO. As stratus approaches in the evening, winds ease, but remain close to 10 knots through much of the night, and slowly turn to become more S/SW ahead of the approaching low pressure system. By the mid morning hours of Saturday, most terminals will see winds increase once more to become breezy and gusty out of the SW, and rain begins, lowering visibilities at terminals. Cloud decks are expected to improve to become MVFR around the same time to slightly after when rain approaches as greater lifting from associated low pressure is enabled. Rain continues through the end of the TAF period for most terminals, with winds turning to become N/NW and breezy. Vicinity of SFO...VFR conditions last through the afternoon today, with strong and gusty onshore winds. Max gusts up to 35 knots are expected. Stratus makes an early return in the evening, bringing IFR conditions. Models suggest a reduction to LIFR conditions in the overnight hours, but at this time, confidence in that development is low. Have kept CIGS IFR and then improving to MVFR in the later morning for now. Rain and gusty SW winds begin just prior to sunrise Saturday for KSFO. Winds turn to become W/NW in the later morning, but rain lasts through the afternoon. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Conditions improve to VFR in the early afternoon today, though only for a few hours before stratus and IFR/LIFR CIGs make a quick push inland in the early evening. Winds NW and breezy this afternoon, but easing into the evening to below 10 knots. IFR/LIFR CIGs last through the majority of the overnight hours. Towards the late morning of Saturday, rain begins and CIGs lift to become IFR. Some model solutions hint at CIGs lifting enough to become MVFR by the end of the TAF period. However, confidence in this outcome is low at this time. For now, have left CIGs as lifting, but remaining in IFR through the end of the TAF period. && .MARINE... (Today through Wednesday) Issued at 457 AM PDT Fri May 3 2024 Strong and gusty northwesterly winds will persist for yet another day as the region remains in between high pressure over the Eastern Pacific Ocean and low pressure over the Southwest. Gale force gusts will be possible, especially over the coastal waters and southernmost zones. Tonight, a cold front will drop down from the Pacific Northwest bringing rain and moderate to fresh breezes across the waters. As the low pressure system exits to the east and the pressure gradient is allowed to relax, winds will diminish going into next week. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay- Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm. Gale Warning until 3 AM PDT Saturday for Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory until 3 PM PDT this afternoon for Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory from 3 AM to 9 AM PDT Saturday for Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...Behringer LONG TERM....Behringer AVIATION...AC MARINE...AC Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea ####018006640#### FXUS63 KABR 032016 AFDABR Area Forecast Discussion National Weather Service Aberdeen SD 316 PM CDT Fri May 3 2024 .KEY MESSAGES... - Scattered rain showers late this afternoon will become more widespread over the eastern part of the region tonight. Rainfall amounts of one quarter to in excess of one half inch are expected along and east of a line from Wheaton, MN to Murdo. - High pressure will bring dry and warmer conditions this weekend. - 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 /THIS EVENING THROUGH SATURDAY NIGHT/... Issued at 315 PM CDT Fri May 3 2024 An upper level trough currently west of the region will track across the Dakotas tonight, with a fairly potent shortwave affecting mainly the eastern part of the CWA. The trough weakens as it exits the area on Saturday, with ridging then building in Saturday night. At the surface, the region is currently situated between a low pressure system over southern Ontario and a low over Colorado. The boundary between these two systems will be the focus for rain late this afternoon and tonight as the aforementioned shortwave moves over the area. Currently seeing some scattered shower activity over mainly the western half of the CWA, but expect this area of rain to become more of a line from southwest to northeast by this evening, generally extending along and east of a line from west central Minnesota to Murdo. The area of rain will then spread eastward tonight. Right now, thunderstorm potential looks to stay south of the CWA, but cannot rule out a stray thunderstorm maybe affecting the southeastern CWA this evening. The highest rainfall amounts are expected along and east of a line from Wheaton, MN to Murdo, where one quarter to one half inch looks to occur. Should a thunderstorm develop, there could be some locally higher amounts. High pressure will settle over the region Saturday and Saturday night, bringing a return to dry conditions. Low temperatures tonight will range from the lower 30s along and west of the Missouri River, to the lower 40s across west central Minnesota. High temperatures on Saturday will be in the upper 50s to mid 60s. Lows Saturday night will be in the mid to upper 30s. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Issued at 315 PM CDT Fri May 3 2024 This forecast period begins Sunday morning on a relatively quiet note compared what were anticipating to be another round of active and wet weather through the majority of next week. Upper level ridging will build overhead on Sunday in response to an upper level trough/low moving through the Great Basin and adjacent regions of the western CONUS. Sfc high pressure will be positioned off to our east while low pressure will be situated across the lee of the Rockies and Northern High Plains on Sunday. Southerly low level flow will intensify through the daytime as the pressure gradient tightens. Increasing southerly winds through the day will potentially reach advisory criteria, especially across our western zones. NBM probabilities of seeing max wind gusts greater than or equal to 34kts(40mph) is high(70-100%) along and west of the Missouri Valley. At this point in time, the thinking is that this is a bit on the high category or extreme, so will continue to take a more conservative approach and keep an eye on trends with incoming future guidance data. With a decent amount of sunshine to round out the weekend and dry conditions expected, we should see a nice warm up. 950mb temps are expected to reach about +13C to +19C which translate to highs in the 60s to low 70s across the forecast area. Unfortunately, all good things have to end sometime and we'll see the pattern shift quickly by Monday into a more active and wet one. The aforementioned upper low is progged by both deterministic and ensemble guidance to track northeastward out of the Rockies into portions of the Northern High Plains and Northern Plains early next week. This system looks to be rather vigorous on Monday as sfc low will track into the Central Plains and shift northward into our region. Severe weather parameters looks best across the Central Plains and south of our region by Monday afternoon and evening, however we can't totally rule out some stronger activity in parts of our area. As of right now, our forecast area is just outside of the northern fringe of the better instability. MUCAPE values on the order of about 300-500 j/kg is possible, especially across our southern zones with far more higher values to the south in parts of NE and KS. We'll just have to keep track of the trends over the next couple days to see if there's any movement farther north with these better ingredients. The upper flow pattern remains unsettled at least through the middle of next week and perhaps even through the end of this period. Guidance progs a stagnant pattern locally with the upper low or trough meandering and spinning just off to our northwest. Multiple s/w's in southwest flow aloft over our region will likely keep on and off shower chances persisting through the week. Underneath the more extensive cloud cover that anticipated, temperatures will be held in check close to normal but probably falling short of average for this time of year. Daytime values in the 50s and 60s can be expected with overnight temperatures in the 40s. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1224 PM CDT Fri May 3 2024 Terminals KABR,KATY,KPIR,KMBG An area of rain currently extending from southwestern South Dakota to central South Dakota will continue to spread to the northeast this afternoon. The rain will come to an end over central South Dakota this evening, but will continue across northeastern South Dakota and west central Minnesota through the nighttime hours. Cannot rule out a thunderstorm or two across east central South Dakota this evening. Periods of MVFR cigs and vsbys will be possible with the rain. VFR conditions will prevail across the area Saturday morning. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ SHORT TERM...Parkin LONG TERM...Vipond AVIATION...Parkin ####018005577#### FXUS65 KCYS 032017 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 217 PM MDT Fri May 3 2024 .KEY MESSAGES... - A cold front will move through the region today with another round of shower activity in the mountains. Snow levels will remain above 6500 feet. - Breezy to windy, and cooler weather expected for Monday through Wednesday, with isolated to scattered late day showers and thunderstorms. && .SHORT TERM /THROUGH SATURDAY NIGHT/... Issued at 159 PM MDT Fri May 3 2024 As the cold front continues to move east across southeast Wyoming and western Nebraska, we saw a weaker dryline develop ahead of it stretching from near Cheyenne to Alliance with southerly winds and dewpoints in the upper 40s ahead of it, and north to northwest winds and dewpoints in the 20s to low 30s behind it. A line of thunderstorms developed along it with pockets of 40 knots of shear and CAPE values near 1000 J/kg, but it was quickly undercut by the approaching cold front and died out nearly as fast as it developed. Rawlins saw some moderate to heavy snow showers this morning, and while they are very slowly moving east, they will likely not impact areas east of Interstate-25, producing very little precipitation between the Laramie Valley and the Interstate-25 corridor, including Cheyenne. The primary impacts to areas between the Laramie Valley and the Interstate-25 corridor for the rest of the day will be occasional light rain showers and snow showers possible above 6500 feet, but mainly strong gusty winds with wind gusts 35 to 45 mph possible and colder temperatures tonight. Saturday the trough moves off to the east as a ridge approaches southeast Wyoming and western Nebraska bringing high temperatures in the 50s to low 60s with clear skies. Winds will likely be light with south to southeast wind gusts 20 to 30 mph possible across the High Plains. Overall a pleasant, cool Saturday expected. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Issued at 159 PM MDT Fri May 3 2024 Warm day Sunday will transition to a prolonged windy and slightly cooler pattern as a storm system slow churns across Intermountain West beginning Monday and persisting into Wednesday. Looking like there is a chance for elevated winds with intermittent periods of high winds to impact the wind prone areas and much of the I-25 corridor and areas across the Nebraska Panhandle. The long term forecast will begin with a nice day on tap for Sunday as upper level ridging settles across the area allowing for 700mb temperatures to climb into the 7-11C which will translate to afternoon high temperatures climbing into the upper 60s to mid 70s for locations east of the Laramie Range and into the Nebraska Panhandle. Ahead of the next storm system increasing clouds and low level moisture will lead to the development of some high elevation snow showers across Carbon county and the Sierra Madres. Not expecting much in the way of impactful accumulation with these snow showers. A combination of a slow moving and strengthening storm system moving to our south and some lee troughing will be the catalysts from a prolonged period of windy conditions across much of SE Wyoming and the Nebraska Panhandle. Not much change regarding the NBM probabilities as they continue to show a period from Monday through Wednesday night where a large swath of SE Wyoming and the Nebraska Panhandle of seeing a (>80%) chance of seeing wind gusts greater than 40 mph Monday through Wednesday with lower intermittent probabilities of periodically seeing wind gusts up to high wind criteria (>58 mph). The wind prones should see more consistent wind gusts above high wind criteria so if we can stay underneath the jet energy aloft and keep those gradients tight then I'd expect we may begin to issue high wind highlights in the coming forecast updates. The extent of the winds and magnitude as stated above will be the track of the low pressure system to our south as a more southerly shift would pull the bulk of the high winds aloft further south into Colorado and this cut down on both the magnitude and duration of the wind threat. This track to the south would also pull the wrap around moisture out of northern Wyoming and southern South Dakota and shift it more into our area increasing the precipitation chances heading into next week. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1110 AM MDT Fri May 3 2024 Snow showers have been moving through KRWL with an associated cold front, dropping conditions to IFR and will likely continue over the next few hours, clearing up by this evening. These snow showers will continue moving east and will begin to affect KLAR over the next two hours, and potentially KCYS in the next four hours. Precipitation type will more likely be rain by the time it reaches KCYS. In addition, thunderstorms will likely begin developing in the eastern Nebraska panhandle this afternoon, if they were to develop and affect any terminal, it will most likely be KAIA. As the cold front moves across southeast Wyoming and western Nebraska, winds will turn more northerly with strong wind gusts 30 to 40+ knots. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...LEG LONG TERM...AW AVIATION...LEG ####018003567#### FXUS63 KILX 032018 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 318 PM CDT Fri May 3 2024 .KEY MESSAGE... - Near daily chances for showers and thunderstorms over the next week as a series of fronts advance across the region. The Tuesday through Wednesday period looks particularly active, with medium confidence in thunderstorms capable of producing all severe weather hazards. && .DISCUSSION... Issued at 127 PM CDT Fri May 3 2024 Current GOES WV imagery depicts a strong upper-level low positioned over western Ontario with more subtle shortwave energy ejecting out of the Great Basin this afternoon. Model guidance remains in excellent agreement that shortwave energy lifts into the Northern Plains and Upper Midwest regions overnight, ultimately helping drag a synoptic cold front into western Illinois Saturday afternoon. A plume of low-to-mid 60s dewpoints is progged to advect northward ahead of the cold front, and mean SBCAPE values should be able to achieve 1000-1500 J/kg as SBCINH erodes in the presence of steep 0-3 km lapse rates (> 7.5 C/km). This all adds up to likely (> 60% chance) thunderstorm development Saturday afternoon along and ahead of the cold front. Coverage of Saturday storms could be limited by somewhat underwhelming deep-layer shear profiles, with much of the area at or below 30 kts in the vicinity of the cold front. Updrafts may struggle to become organized or struggle to stay organized, especially some of the early updrafts, and recent CAMs hint at this as well. Nevertheless, CAPE/Shear profiles are just good enough to support the potential for an isolated severe hail and wind threat. As storms move toward and east of I-55 Saturday evening, the severe potential should gradually fade. This will largely be due to the loss of daytime heating and the lack of a LLJ to help augment instability. This thinking lines up well with SPC's Day 2 Marginal Risk, which ends near the I-57 corridor. Flooding should not be a concern with the Saturday storm event. NBM Mean QPF is around 0.25", and this guidance only offers a 10% chance that rainfall exceeds 0.75", which is well below 3-hour flash flood guidance. The rest of the weekend through Monday should be fairly low drama, with the main frontal zones displaced just to our south. Attention quickly turns to the Tuesday - Wednesday timeframe as persistent, deep southwest flow envelops the region ahead of an elongated upper-level low. While we're running lean on details at this timeframe, the synoptic pattern (kinematics/thermodynamics) being modeled supports a multi- day severe weather threat across portions of the Plains and Midwest. This strong signal in the global models is also reflected in the analogs and machine learning progs for severe weather potential. MJA && .AVIATION... (For the 18z TAFs through 18z Saturday Afternoon) Issued at 1242 PM CDT Fri May 3 2024 Areas of broken stratus will continue to be observed in the vicinity of the surface cold front. The BMI/DEC/CMI terminals may experience broken MVFR ceilings through 23z/6pm before the front departs further east and skies clear out. Surface winds will become light and variable overnight with patchy fog developing. Coverage and confidence in fog remain too low to include mention in this TAF cycle. MJA && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$ ####018005962#### FXUS64 KSHV 032019 AFDSHV Area Forecast Discussion National Weather Service Shreveport LA 319 PM CDT Fri May 3 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (This evening through Saturday Night) Issued at 317 PM CDT Fri May 3 2024 Convection that originated across Oklahoma and North Texas late yesterday has finally departed the area as a shortwave trough lifts northeast towards the Tennessee River Valley. Farther southwest, another weak perturbation in the southwesterly flow aloft has helped to sustained showers and thunderstorms along a remnant outflow boundary across Southeast Texas and South Louisiana. Radar trends over the last couple of hours continue to show redevelopment along the northwest flank of this line in Central Texas. So far, this activity has been quickly weakening with eastward extent as it nears our Deep East Texas counties, mostly likely encountering a more stable airmass. Current thinking is the heaviest precip should remain south and southwest of the area and should dissipate by sunset with the loss of diurnal heating and weakening of large scale forcing. The latest CAMs suggest a few isolated to widely scattered showers are possible this evening and tonight, mainly north of Interstate 20, but only slight chance PoPs were kept in the forecast. Overnight, another complex of showers and thunderstorms is expected to form ahead of a cold front across Kansas and Oklahoma, which should dive southeast towards the CWA. This complex should be weakening as it moves into southeast Oklahoma around daybreak Saturday. However, renewed development and intensification is expected, especially during peak daytime heating in the afternoon. Based on the latest CAMs and short- range ensembles, current thinking coverage will mainly be scattered but will likely coverage much of the area. Given the expected coverage, I felt the NBM PoPs were too way and much of the short-term rain chances were trended toward the HREF. There should be enough instability and deep layer shear to support a marginal risk for large hail and damaging winds, especially during Saturday afternoon through early evening. Initial development in the afternoon may begin as far north as I-30 before spreading southeast across the region. At the risk of sounding like a broken record, another complex of strong to severe storms will develop along the dryline in West Texas and may begin to affect the area early Sunday morning. CN && .LONG TERM... (Sunday through next Thursday) Issued at 317 PM CDT Fri May 3 2024 Robust convection will likely be ongoing across the area near or shortly after sunrise Sunday morning. While the cold front is once again expected to stall in our northern zones before retreating back to the north again, a potent shortwave trough moving across Texas and Oklahoma should help sustain strong thunderstorms for much of the day Sunday. A few isolated severe storms will be possible, mainly posing a risk for damaging winds. Rain chances should diminish during the evening as the shortwave lifts northeast and forcing weakens. Locally heavy rainfall will be possible, especially in Deep East Texas south of I-20. However, current thinking is that the threat for flooding will remain isolated and localized, and it will have been a few days between rain events. However, if QPF amounts increase in future forecasts, a Flood Watch may need to be issued. Unsettled weather will remain in the forecast into next week with near daily chances for scattered showers and thunderstorms, especially north of I-20 as deep southerly flow persists across the region. A longwave trough will move northeast across the Central and Northern Plains pushing a cold front closer to the region. This should bring a chance for more strong, possibly, severe thunderstorms to parts of the area next Tuesday and Wednesday. The extent of the severe weather threat is still highly uncertain, but the best chances appear to be north of I-20, and especially across Southeast Oklahoma and Southwest Arkansas. Another growing concern will be the unseasonable heat. Strong southerly flow and warm air advection will result in rising temperatures despite the persistent rain chances in the forecast. From Tuesday through Thursday, there is a high chance (60 to 80 percent chance) of daytime high temperatures of 90 degrees F or greater across much of Louisiana and into portions of Southwest Arkansas and Deep East Texas. Combined with the high humidity, peak heat index values should be near or above 100 degrees F. Cooler temperatures may return by the end of the week. CN && .AVIATION... (18Z TAFS) Issued at 1248 PM CDT Fri May 3 2024 For the ArkLaTex terminals, we began the day w/ a TS outflow sandwich from NtoS along I-20 w/ KMLU about to scatter in the wake. The N boundary won out holding over E TX, but may go quick gusting from the S now . We have a cluster of TS lifting toward KLFK with a cautious tempo there 18-21Z. Otherwise, may add VCTS to KTYR/KGGG/KSHV if the sea breeze joins in later today. We should see a quiet night with IFR/MVFR 06-15Z and better TS chances in the aftn hrs Sat & nocturnal again daybreak on Sun. /24/ && .PRELIMINARY POINT TEMPS/POPS... SHV 67 85 68 79 / 20 50 40 80 MLU 64 86 67 80 / 20 40 30 60 DEQ 64 82 65 75 / 20 40 50 90 TXK 66 84 66 78 / 20 40 40 80 ELD 63 84 65 79 / 20 50 30 70 TYR 68 82 66 78 / 10 40 60 80 GGG 67 83 67 78 / 10 50 50 80 LFK 67 84 68 80 / 10 40 40 80 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ SHORT TERM...09 LONG TERM....09 AVIATION...24