####018005071#### FXUS64 KSJT 251014 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 514 AM CDT Thu Apr 25 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (This evening through Thursday) Issued at 440 AM CDT Thu Apr 25 2024 A shortwave aloft will be positioned just to our west across New Mexico by Thursday afternoon and evening. This will combine with a dryline across the region during this same time period and also overnight. These features will serve to spark thunderstorms along the dryline boundary during the evening. Regarding this afternoon, however, this activity will initially be inhibited by a capping inversion aloft. This will make the development of the convection difficult and should limit coverage during the afternoon (prior to 7 PM CDT). It's important to note that this feature continues to produce some amount of uncertainty for this forecast. If this cap is broken during the afternoon, the thunderstorms that do develop will quickly become severe given the ample wind shear and instability that will be in place. Large hail (2"+) will be the predominant concern during the afternoon along with a couple of tornadoes and damaging winds (60-70 MPH). As we move forward into the evening hours, the coverage is expected to increase after 7 PM CDT. This will result from the reduction in the capping inversion aloft as the wave moves further east. This weakening of the cap should allow for more widespread convection. Conditions will remain favorable for large hail (2"+) and a couple of tornadoes. The threat of damaging winds (60-70 MPH) will increase overnight and continue into Friday morning as this activity moves off to the east by 7 to 9 AM CDT. && .LONG TERM... (Friday through Wednesday) Issued at 450 AM CDT Thu Apr 25 2024 Showers and thunderstorms may be ongoing Friday morning across far southeast portions of the forecast area but should move east of the area by late morning. The dryline is expected to stall over southeast counties Friday afternoon. Isolated strong convection may develop along the dryline during peak heating, but the bulk of any thunderstorm development should remain east of the area into the evening hours. Rich low level moisture will rapidly return across the area Friday night, as the dryline retreats westward, ahead of the next mid/upper level trough developing over the Desert Southwest. This system will bring the potential for additional severe thunderstorms to the area from Saturday afternoon into Saturday night/early Sunday morning. Low level and deep layer shear will increase considerably across the area, especially Saturday evening/overnight, with moderate to strong instability developing in the warm sector by Saturday afternoon. Showers and thunderstorms may develop as early as Saturday morning, primarily across the Big Country, but more widespread thunderstorm development is expected along and ahead of the the dryline Saturday afternoon and early evening. Shear profiles will support supercells with large to very large hail and some tornadoes. The tornado threat may increase Saturday evening, with the potential for a few strong tornadoes as the low level jet strengthens and low level shear increases. At this time it appears the greatest tornado threat will be across eastern portions of the Big Country. Scattered to numerous showers and thunderstorms will be possible over much of the area overnight, with a continued severe threat. Precipitation is expected to diminish over southeast counties Sunday morning. For early next week, low rain chances will be possible mainly over southeast counties Monday and Tuesday afternoon but most of the area should remain dry. Another shortwave trough may bring additional showers and thunderstorms to the area by mid week but details are uncertain this far out. && .AVIATION... (06Z TAFS) Issued at 1211 AM CDT Thu Apr 25 2024 MVFR ceilings have developed across portions of our area this morning, as indicated by ASOS observations. Models continue to show these conditions worsening to IFR levels in some instances with most locations dropping to at least MVFR levels. In addition, winds are expected to increase overnight and continue through tomorrow. Thunderstorm chances will increase tomorrow night and may be reflected in future TAF issuances as that time frame approaches. && .PRELIMINARY POINT TEMPS/POPS... Abilene 82 63 85 64 / 10 70 10 10 San Angelo 83 63 88 63 / 10 60 0 10 Junction 87 68 92 66 / 10 30 20 0 Brownwood 82 65 86 65 / 10 60 40 10 Sweetwater 82 62 85 62 / 10 60 0 10 Ozona 81 63 88 64 / 0 40 0 10 Brady 82 67 87 66 / 10 50 30 10 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...41 LONG TERM....24 AVIATION...41 ####018006250#### FXUS61 KBUF 251015 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 615 AM EDT Thu Apr 25 2024 .SYNOPSIS... Canadian high pressure will build southeastward across our area today...before slowly drifting to the New England coastline Friday. The high will provide us with fair dry weather through Friday...with below normal temperatures today and tonight giving way to somewhat above average readings on Friday as a southeasterly return flow of milder air overspreads our region. The warming trend will then continue over the weekend and into early next week...resulting in summerlike warmth engulfing our region both Sunday and Monday. While there will also be some showers and thunderstorms around, particularly during Saturday...a fair amount of dry time can also be expected. && .NEAR TERM /THROUGH TONIGHT/... ...Unseasonably Cold Conditions Expected Again Tonight... Sprawling Canadian surface high pressure will settle directly across our area today...then will only begrudgingly begin to drift eastward tonight. Aside from some patchy valley fog across the Southern Tier early this morning...this will result in continued fair dry weather throughout this period...along with largely clear skies. Given the cool airmass temperatures will remain solidly below normal...with today's highs struggling to get much above the mid 40s to lower 50s in most places even in spite of abundant sunshine...with the coolest readings found across the higher terrain and along the south shore of Lake Ontario...where developing onshore flow will keep things cooler. Another downright cold night will then follow tonight...with lows ranging from the lower 20s east of Lake Ontario to the mid and upper 20s across much of the rest of the area...and to around 30 close to Lake Erie. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... Surface high pressure centered across New England will ridge back across our region resulting in fair and sunny weather for Friday. After this, a trough of low pressure will track into the Western Great Lakes with an associated warm front moving across the area Saturday. 00Z model guidance is a bit slower with this, with a mid- level ridge keeping our region rain-free until late Friday night when some showers could enter far Western NY. The front will be far removed from the parent low, with a weakening trend as it moves eastward across the area Saturday into Saturday night. For Sunday, the risk for showers will mainly be instability/diurnally driven. Hedge on the lower side of model guidance for PoPs due to the convective nature of the precipitation, especially downwind of the lakes Sunday afternoon. Following the warm frontal passage some thunder may occur Saturday night and Sunday with limited MUCAPE values less than 500 J/KG. It will be warmer with the warm frontal passage, especially in areas near the lakeshores which benefit from a southerly downslope flow. Highs on Friday and Saturday will mainly be in the upper 50s to mid 60s, and it could be a bit warmer than that Saturday depending on the timing of the showers. Temperatures will climb into the 70s at most locations for Sunday. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... An upper level ridge axis across the area Sunday night will gradually shift to the east through mid-week. This will result in above normal temperatures and 'mostly' rain free weather for Sunday night and Monday. Monday will almost feel summer-like with highs reaching 80F at many locations. As a surface low marches toward Quebec Monday night through Tuesday, its attendant surface cold front will approach the region from the west and then cross from west to east. Initially expect some thunderstorms ahead of the front's arrival Monday night and then rain showers with the front's passage Tuesday. Additionally with the front's passage Tuesday, expect temperatures to be cooler than Sunday and Monday with highs ranging in the upper 60s to low 70s, though still well above average for the end of April. A secondary cold front will then cross the area from north to south Wednesday supporting a small chance for a few rain showers. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... Canadian high pressure centered north of Georgian Bay will build directly overhead today...before slowly drifting east to eastern New York and western New England tonight. Aside from some patchy valley fog and attendant localized reductions across the Southern Tier early this morning...this will guarantee fair dry weather and unlimited VFR conditions right through the TAF period. Outlook... Friday...VFR. Saturday...VFR/MVFR with some showers likely and an isolated thunderstorm possible. Sunday and Monday...Mainly VFR with a chance of showers and thunderstorms. && .MARINE... Sprawling high pressure centered north of Georgian Bay will continue to build across our region today...before slowly drifting east to eastern New York and western New England tonight. This will provide our region with fair dry weather and light to modest winds through tonight...with local lake breeze circulations developing on Lake Ontario during the course of today and resulting in winds there turning locally onshore around 10 knots. Meanwhile on Lake Erie northeasterly winds of 10-15 knots are expected today...resulting in some chop even though conditions will remain below advisory criteria. On Friday the surface high will slide east to the New England coastline...with a general easterly to east-northeasterly flow continuing across the Lower Great Lakes. On Lake Ontario winds will be more easterly...and could become strong enough to bring some marginal SCA conditions to the southwestern shore of the lake during the afternoon. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ SYNOPSIS...JJR NEAR TERM...JJR SHORT TERM...Apffel LONG TERM...Apffel/EAJ AVIATION...JJR MARINE...JJR ####018007817#### FXUS63 KOAX 251016 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 516 AM CDT Thu Apr 25 2024 .KEY MESSAGES... - Several rounds of showers and thunderstorms are expected, beginning tonight and continuing through Sunday. - Severe weather appears likely (>80% chance), especially during the afternoon and evening hours on Friday, Saturday, and perhaps Sunday. - Flash flooding is also a concern due to the potential for repeated thunderstorm activity over the same areas. && .DISCUSSION... Issued at 516 AM CDT Thu Apr 25 2024 .Today and tonight: Warm/moist advection occurring along a 40-50 kt nocturnal low- level jet has supported widely scattered shower and thunderstorm development from western NE into eastern KS early this morning. And, latest CAM output suggests that an elevated thunderstorm complex will evolve prior to daybreak across portions of western and central NE with parts of southeast NE being affected by those storms later this morning. An interesting signal that has been consistently shown over several runs of the HRRR is a corridor of 40-50+ kt wind gusts overspreading southeast NE later this morning, on the northeast flank of the more intense storms tracking from south-central NE into northeast KS. It's not readily apparent what mechanism in the model is driving the strong winds, but we will be on the lookout for their development. The early-day storms will move to the south of the area by afternoon with the models indicating only weak reflectivity structures across the area within a persistent warm advection regime. Highs today will be limited by widespread cloud cover with readings in the low to mid 60s. By this evening, increasing height falls/forcing for ascent downstream from a vigorous midlevel trough emerging into the central and southern High Plains will support the development of thunderstorms over northwest KS into south-central NE. That thunderstorm complex is expected to increase in areal coverage while spreading northeast into our area from late evening into the overnight hours. The storms will be elevated to the north of a warm front lifting though KS with forecast soundings suggesting the potential for severe hail with the strongest updrafts. Additionally, recent CAM data suggest the potential for embedded bowing structures, which could promote a few damaging wind gusts to the surface despite the convection being rooted above a stable, near-surface layer. Finally, localized flooding is also a concern in areas of regenerative/training storms. .Friday and Friday night: The 00z global models remain in good agreement in suggesting that a vertically stacked, but progressive low pressure system will move into central NE by midday Friday before reaching northeast NE by early evening. Meanwhile, an associated warm front will lift north through eastern NE and western IA during the day as a Pacific front advances into eastern NE during the afternoon. Latest model data suggest the Pacific front will serve as the focus for severe thunderstorm development during the afternoon and evening hours. Showers and thunderstorms may be ongoing Friday morning; however, the northward advection of the system dry slot should allow for cloud breaks and resultant air mass destabilization by afternoon ahead of a Pacific front approaching the area from the west. Forecast soundings within the destabilizing warm sector exhibit steep lapse rates through a deep layer (owing to cold temperatures attendant to the midlevel low), supporting the potential for moderate instability amidst a kinematic environment favorable for organized storm modes, including supercells. The primary hazard will be large hail, potentially up to 2-3" in diameter. Multi-model consensus indicates the strongest low-level shear developing from far eastern NE into western IA from late afternoon into evening where tornadoes (including one or two of EF-2+ intensity) are most probable. Tornado potential will extend into northeast NE along the arcing Pacific front/frontal occlusion where a favorable overlap of low-level CAPE and vertical vorticity will reside. The afternoon/evening storms are expected to advance to the northeast of the area Friday night in conjunction with the low pressure system moving into southern MN. High temperatures will range from 60s north where clouds and areas of precipitation could linger to 70s near the KS and MO borders where breaks in the clouds are expected. .Saturday and Saturday night: The surface front trailing the lead low pressure system over the upper MS Valley will bisect the area Saturday with that feature extending southwest to a deepening surface low over western KS. It still appears that we will see a break in shower and thunderstorm chances Saturday morning into early afternoon with high temperatures ranging from 60s in northeast NE to lower 80s in far southeast NE. Later Saturday afternoon into Saturday night, another significant shortwave trough will pivot across the southern into central Plains, supporting the deepening of the surface low over KS and the northward movement of the surface boundary through our area. Thunderstorms are expected to develop by late afternoon into evening, along and south of the surface front within an environment favorable for organized storm modes with all severe weather hazards possible. Showers and thunderstorms are likely to continue Saturday night into Sunday morning with an increased risk for flash flooding owing to greater runoff potential. .Sunday and Sunday night: The 00z global models suggest that this second low pressure system will take a similar track to the the Friday system with a cold front moving into eastern NE during the afternoon hours. It appears that the attending midlevel dry slot will overspread far eastern NE and western IA during the afternoon hours, allowing for at least modest air mass destabilization to occur. As such, the potential will exist for a few severe storms during the afternoon and evening hours with the primary hazard being large hail. The forecast will indicate Sunday's highs ranging from 50s in northeast NE to 70s in southeast NE and southwest IA. .Early next Week: A quasi-zonal midlevel pattern is forecast to develop early next week with some model differences in the timing and amplitude of embedded shortwave troughs moving through that pattern. Guidance suggests that a cold front will move through the area Tuesday with low shower and thunderstorm chances Tuesday into Tuesday night. Highs in the 60s Monday are expected to warm into the 70s to lower 80s ahead of the front Tuesday. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1141 PM CDT Wed Apr 24 2024 Widespread cloud cover and spotty showers are currently ongoing across the region. With some showers not reaching the ground and spotty coverage of convection, have opted to keep rain out of TAFs for tonight except at KLNK. Highest rain chances will be along and south of Highway 34 after 12Z. Ceilings will steadily lower over the course of the TAF period with IFR ceilings expected at all TAF sites by the end of the forecast period. Moderate to heavy icing will be possible between 13000 and 19000 feet from 09Z to 18Z across all of eastern Nebraska and western Iowa. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Mead AVIATION...Darrah