####018005697#### FXUS65 KTFX 041120 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 520 AM MDT Sat May 4 2024 ...AVIATION SECTION UPDATED... .SYNOPSIS... Weak high pressure will keep North Central, Central, and Southwest Montana dry and a bit warmer than normal through tonight with gusty southeasterly winds. However, a Pacific weather system will first bring an increasing chance for showers and thunderstorms to the area on Sunday, then more widespread mountain snow and low elevation rain with cooler than normal temperatures Monday through Thursday. Warmer and drier conditions should then move in to end the week. && .DISCUSSION... Today and Tonight... High pressure aloft will keep this period dry and a bit warmer than normal across North Central, Central, and Southwest Montana. However, a cold front approaching Montana from the west ahead of a Pacific low pressure system will combine with an exiting area of surface high pressure to strengthen the surface pressure gradient over the area. This is forecast to bring southerly winds gusting in excess of 30 mph at times today across the area, with the winds shifting more easterly tonight and remaining gusty. Sunday through Sunday Night... The Pacific system is forecast to move east across the Great Basin on Sunday, which put the area under an increasingly moist and unstable southerly flow aloft as the Pacific cold front moves across the area. This should spread showers over most of the area Sunday into Sunday evening with a few embedded thunderstorms. The main threats from these storms will be isolated lightning strikes, brief heavy rain showers, and gusty winds, but some small hail is also possible. The main threat for thunderstorms will diminish during the evening, but snow levels will start to lower from the southwest overnight as the low pressure area is forecast to move northeast into Southwest Montana. This will likely result in at least some light accumulations of wet snow above 6000 feet, which may cause some travel problems over mountain passes, so some winter weather highlights may be needed starting Sunday night in Southwest Montana. Monday through Thursday... This is forecast to be coolest, wettest, and windiest period of the upcoming week. The low pressure center is predicted to continue moving northeast to around the Montana/North Dakota border Monday into Monday night, where it seems to deepen and cut off from its main trough, causing it to remain there into Wednesday. This will result in deep moisture wrapping around the low and bringing widespread mountain snow and low elevation rain to the forecast area, as temperatures cool back below normal. The heaviest precipitation amounts are forecast to be closest to the low pressure center, which includes the plains of North Central Montana; probabilistic guidance gives a 50 to 70 percent chance of at least 1 inch of precipitation there for Monday through Wednesday night, with a 40 to 50 percent chance of 2 inches of precipitation across Hill, Blaine, and Chouteau Counties. However, this same guidance gives at least a 50 percent chance of 12 inches or more of snow to the mountains of the Rocky Mountain Front, the Little and Big Belt mountains of Central Montana, and the mountains of Gallatin and Madison Counties; in fact, there is a 70+ percent chance of 24 inches or more of snow in the Little Belts. In addition, models are forecasting that northwest winds moving around the low pressure area at the mid levels of the atmosphere could exceed 60 mph on Tuesday, which may translate down into at least the mountains, if not the plains of North Central Montana, mainly on Tuesday. Overall, confidence is increasing in the potential need for winter weather highlights in the mountains and wind highlights on the plains. However, run-to- run model inconsistency adds uncertainty to timing and location for such highlights, so will hold off for now. Overall, though, the system should start exiting the area on Thursday. Friday through next Saturday... Ensemble model clusters are in good agreement with bringing high pressure into Montana late in the week, but just how strong it will be, and just how warm the temperatures will be, remains uncertain. Regardless, this should bring drying conditions to the area with a return to warmer than normal temperatures. -Coulston && .AVIATION... 520 AM MDT Sat May 4 2024 (04/12Z TAF Period) Aside from some isolated fog patches over the far southwest valleys this morning, VFR conditions are expected for most if not all of the 04/12Z to 05/12Z TAF period. However, keep in mind that mid- and high level clouds will continue to increase today and tonight, and a few light showers will begin lifting northward into far Southwest Montana after 05/00Z. Light east to southeasterly surface winds increase today and may gust up to 25 mph at times. - RCG Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 63 42 64 42 / 0 10 30 90 CTB 58 37 59 40 / 0 10 20 30 HLN 67 44 68 43 / 10 10 60 80 BZN 65 41 66 36 / 0 10 70 80 WYS 59 36 53 28 / 0 30 90 90 DLN 64 44 60 36 / 0 20 70 90 HVR 63 39 70 43 / 0 0 10 80 LWT 58 36 66 39 / 0 0 20 80 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls ####018005361#### FXUS62 KCHS 041122 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 722 AM EDT Sat May 4 2024 .SYNOPSIS... Atlantic high pressure will remain across the Southeast U.S. through much of next week. && .NEAR TERM /THROUGH TONIGHT/... Based on early morning radar trends, the forecast will feature SCHC PoPs across portions of the outer GA waters and greater values over the land zones. In addition, temperatures at daybreak were 1-3 degrees warmer than the current forecast. The updated forecast will align hourly temperatures to recent observations. Otherwise, the forecast appeared on track. The forecast area will remain between a H5 ridge over the western Atlantic and broad trough over the western Carolinas and northern GA today. Early this morning, KCLX detected a few weak showers over inland GA, tracking north. Additional rounds of showers may develop over inland GA/SC later this morning, highlighted with SCHC to CHC PoPs for SHRA. Recent runs of the HRRR indicated that at least isolated showers developing over coastal GA during the pre-dawn hours, we will continue to monitor. The latest forecast will indicate dry conditions until mid-day. This afternoon, high temperatures across the region are forecast to generally range around 80 degrees. A sea breeze should advance inland early this afternoon, triggering showers and thunderstorms. Coverage is expected to remain the greatest across the inland counties. Thunderstorm activity should gradually decrease this evening as the sea breeze pushes inland and temperatures begin to cool around sunset. The sfc pattern is expected to support light SSE winds through tonight. The light SSE winds combined with mostly cloudy sky conditions should keep temperatures in the upper 60s along the coast with mid 60s inland. The mid-level trough is forecast to swing east over the CWA late tonight. Guidance indicates that a band of moisture convergence will develop from the Gulf Stream northwest across the South Santee basin late tonight. Scattered showers and isolated thunderstorms will be featured in the forecast for late tonight over the SC waters and portions of Charleston and Berkeley Counties late tonight. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... A mid-level ridge will sit off the Southeast coast as passing waves of shortwave energy ripple across the region through the short term forecast period. High pressure will remain the primary feature at the surface. Convection will be a bit active Sunday and Monday with the presence of a weak shortwave aloft and deeper moisture - noted by PWATs around 1.5-1.7 inches. Coverage of showers/thunderstorms will be highest in the daytime when instability is maximized, but activity could linger into the late evening with some upper forcing present. The greatest POPs are focused in southeast South Carolina and away from the immediate coast each day owing to the juxtaposition of upper forcing and the inland moving sea breeze. Chances for showers/thunderstorms will be slightly less Tuesday as the deeper moisture and remnant shortwave energy moves off the Mid Atlantic coast. High temperatures will generally peak in the low to mid 80s Sunday, warming into the mid 80s Monday, then into the upper 80s Tuesday. Min temperatures both Sunday and Monday are only expected to drop to the mid/upper 60s, with locations along the beaches and Downtown Charleston in the lower 70s. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... Atlantic high pressure will persist through the majority of next week before a cold front approaches late next week. Rainfall chances are little to none as a ridge rebuilds overhead. This will cause temperatures to rise into the low/mid 90s through the remainder of next week, approaching record levels Wednesday and again Thursday. && .AVIATION /11Z SATURDAY THROUGH WEDNESDAY/... VFR conditions are expected to prevail at KCHS, KJZI, and KSAV through 12z Sunday. A few showers may pass near the KCHS and KJZI terminals this morning. This afternoon, shower and thunderstorm activity should mostly stay to the west of the terminals along a sea breeze. Winds should favor a south- southeast direction during the daylight hours, becoming light and variable late tonight. Extended Aviation Outlook: Brief flight restrictions are possible within isolated to scattered showers/thunderstorms through Tuesday. && .MARINE... The surface pattern will yield south-southeast winds between 5-10 kts today and tonight. Wave heights are forecast to favor values around 2 ft, with 3 ft seas possible beyond 40 nm late tonight. Sunday through Thursday: Atlantic high pressure will maintain relatively benign conditions over the local marine waters. Southerly winds in the morning will back slightly during the afternoon and evening hours nearly each day as the sea breeze develops. Winds will average 10-15 kt with seas 2-4 ft. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...NED SHORT TERM...BRM LONG TERM...BRM AVIATION...BRM/NED MARINE...BRM/NED ####018003979#### FXUS63 KILX 041122 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 622 AM CDT Sat May 4 2024 .KEY MESSAGES... - Level 1 (Marginal) Risk of severe storms from late Saturday afternoon into evening for all of central and southeast IL. - Periodic chances of showers and storms Monday through Friday, with severe storm potential elevated on Tuesday and Wednesday during the late afternoon into evening each day. && .DISCUSSION... Issued at 310 AM CDT Sat May 4 2024 The latest IR satellite images show Illinois in the coll zone between two systems, with high pressure providing mostly clear skies and light winds across the CWA. Ongoing storms across eastern Nebraska and Kansas will continue to make slow progress toward the mid-Mississippi River Valley as a cold front approaches. Low level flow will increase ahead of that feature from the southwest, boosting low level dewpoints into the low to mid 60s this afternoon. That will support instability parameters climbing into the 1000-1500 J/kg MLCAPE range ahead of the front, despite thickening anvil cirrus and mid clouds this afternoon. Marginal shear values around 30kts will be a limiting factor in severe storm potential, as a broken line of storms progresses into central Illinois between 3 pm and 5 pm. Chances for any rainfall will peak at 60-70% west of I-55, and remain in the chance category east of I-55. A marginal threat for large hail and damaging wind gusts will be present 22z/5pm through around 01z-02z before diurnal stabilization limits updrafts. By the time the line reaches I-57 the lightning threat will be diminishing/ending. The next period of concern will start on Tuesday as a stationary front across southern Illinois lifts north as a warm front in response to surface cyclogenesis in the Plains. Warm sector shear and instability parameter space will be more favorable for severe weather, as 0-6km shear climbs over 60kts along with MUCAPE climbing toward 2500 J/kg under the support of 65+F deg SFC dewpoints. All severe hazards will be in play as supercells develop during the evening across central Illinois. The upper trough will evolve eastward on Wednesday, dragging a cold front across Illinois during the late afternoon and evening time frame. There are some differences in the model guidance timing of the trough evolution, but Grand Ensemble guidance is pointing toward 40-50% chance for bulk shear of at least 50kts and CAPE of at least 2000 J/kg both Tuesday and Wednesday for areas south of I-72. The best shear is along an axis northwest of the best instability, but enough overlap exists for a wave of severe storms each late afternoon and evening. Additional storm chances will linger through Friday, but at a much lower coverage and intensity per long range guidance. Total rainfall over the next 7 days looks to climb into the 1 to 2 inch range, especially south of I-72, where Grand Ensemble probs show 50-60% chance of over 2 inches. Some rivers may climb back toward minor flood stage due to saturated soils allowing for higher runoff into streams. Shimon && .AVIATION... (For the 12z TAFs through 12z Sunday Morning) Issued at 622 AM CDT Sat May 4 2024 FEW to SCT high clouds will overspread the area today, with VFR conditions expected through much of this afternoon. A line of thunderstorms will move through central Illinois late this afternoon into evening, with the highest chances (60%+) for thunder being west of I-57. A cold front will shift winds from the south to west- northwest tonight, with speeds generally <15 kts expected. MVFR clouds become likely later this evening and will linger through the overnight hours for most airfields. NMA && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$ ####018009844#### FXUS63 KLOT 041122 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 622 AM CDT Sat May 4 2024 .KEY MESSAGES... - A line of scattered thunderstorms is expected to cross the area late this afternoon into mid-evening, with locally strong to severe wind gusts to 60 mph possible. - Periodic shower and thunderstorm chances are expected next week. There is a potential for strong to severe storms along with a locally heavy rainfall threat on Tuesday. && .DISCUSSION... Issued at 314 AM CDT Sat May 4 2024 Through Sunday: A retreating surface ridge extending southwestward across the western Great Lakes will give way to ongoing lee cyclogenesis ahead of a mid-level trough entering the central Great Plains early this morning. Robust convection from northern OK into western IA has likely enhanced the trough, with multiple MCVs evident along this corridor. An associated cold front just behind this convection will become the main focus for storm potential into our area later this afternoon into this evening. Surface dew point trends today will be an important factor on the coverage and intensity of storms into the forecast area. Friday's weak cold front has since stalled across central Illinois and will jump northward in response to diurnal warming and moistening today. However, the magnitude of moistening primarily from evapotranspiration remains less clear this afternoon. Current thought is daytime mixing into a very dry layer above the growing PBL will with offset rising dew points or at least reduce the depth of moisture sufficient for development and maintenance of convection. Have opted to use only scattered thunderstorm wording even as some CAMs depict higher coverage as a result of higher modeled dew points. While it is expected that a more prominent MCV currently near Omaha will lift NE within the broader mid-level steering flow this morning, the extreme southern influence of this MCV may clip the northwest CWA late this morning. Capping should remain far too high to support convection this far southeast, but isolated attempts at convection may reach as close as far northwest Illinois. Overall expectations are for a line of broken showers and storms to develop/intensify roughly along and around the Mississippi River by mid-afternoon within a pre-frontal ribbon of higher theta-e air. Coverage of thunderstorms should then begin a slow downward trend across the forecast area late afternoon through mid-evening as the drier pre-storm environment becomes less favorable with time. However, given an increasing reservoir of DCAPE with eastward extent across the CWA, the potential for strong to locally severe wind gusts may actually maximize across the west half of the CWA up to and through sunset. The antecedent dry air ahead of these storms combined with diurnal mixing of low-level moisture speaks to this wind risk, with the strongest winds likely occurring with any existing loosely organized multi-cell cluster or collapsing cores as storm intensity wanes with time. After the storms and cold front clear the forecast area by early Sunday morning, dry and cooler conditions are expected through the remainder of the period. Kluber Sunday Night through Friday: Quiet weather starts the period Sunday night, as surface high pressure is progged to be drifting east across the Great Lakes region. Farther south, guidance continues to depict mid-level short wave approaching IL late, though it is deamplifying as it moves into the short wave upper level ridge axis. Forecast soundings depict very dry low and mid-levels initially in place across the forecast area, though persistent isentropic ascent and associated warm/moist advection does eventually produce saturation and precipitation development into central IL/IN and the LOT/ILX border region after midnight. Mid-level lapse rates are unimpressive in forecast sounding guidance, suggesting little/no thunder threat. Showers are expected to persist into Monday across the southern parts of the cwa as the mid-level wave continues its transit of the area. NBM blended pop guidance appears to spread too far north in this scenario, and note that much of the EPS/GEPS/GFS ensembles are dry along/north of the I-88 corridor through the day across northern IL. Farther west, guidance continues to depict a deep upper level trough across the western CONUS, within which a strong, negative-tilt short wave develops a closed upper low over the northern high plains by Monday night. Along with a series of short waves propagating around the southeast periphery of the upper circulation and upper level diffluence ahead of a strong cyclonically-curved upper jet, this sets the stage for southerly low level warm/moist advection from the western Gulf into the mid-Mississippi Valley and upper Midwest Monday night, with a northward lifting warm front spreading into the area into Tuesday morning. Thus shower and thunderstorm chances look to ramp-up into the forecast area from the west especially after midnight and into Tuesday morning. While the primary upper/surface lows will be well to our northwest Tuesday, guidance continues to depict a strong mid-level jet is progged to spread east across the area during the day, with a surface wave developing along an occluding cold front approaching the Mississippi Valley later in the day. Combined with a warm, moist and conditionally unstable low- level air mass, additional thunderstorms (potentially strong to severe) are likely within the region Tuesday afternoon/evening. In addition to severe weather, high precipitable water values around 1.75 inches will support locally heavy rainfall will be possible especially if storms train over a particular area. SPC and WPC outlooks for Tuesday for both severe and heavy rainfall potential continue to appear appropriate at this distance. The upper trough is forecast to drift east across the upper Midwest and northern Great Lakes region during the mid and late week period, maintaining an active weather pattern across our forecast area. While the primary low-level theta-E axis will shift southeast of the forecast area Wednesday through Friday, a series of short waves rotating through the southern periphery of the upper Midwest upper low will likely produce additional periods of showers and thunderstorms, especially during the diurnally more favorable afternoon and evening hours. Temperatures will remain above average through most of the period, with daytime highs in the 70s to low 80s (Tuesday and Wednesday have the potential to be the warmest days). Cooler, more average temperatures are expected by Friday, with highs in the mid-60s. Ratzer && .AVIATION /12Z TAFS THROUGH 18Z SUNDAY/... Issued at 607 AM CDT Sat May 4 2024 Aviation Key Messages: - IFR stratus may approach KGYY from the east this morning, but should lift/scatter as it does. - Scattered gusty thunderstorms this afternoon/early evening. - MVFR ceilings likely behind a cold front late tonight into Sunday morning. - Winds become southeast this morning, then south-southwest around midday. Winds may become somewhat variable behind storms this evening, before shifting north-northeast behind the cold front tonight, and eventually northeast Sunday morning. Weak surface low pressure was over south central IA this morning, with a cold front trailing into the southern Plains. This low and cold front will move east-northeast to the western Great Lakes by early this evening, with high pressure building eastward into the region Sunday morning. Early this morning, an area of LIFR stratus/fog had developed across MI and far northern IN, and was moving west-northwest. With the sun already up and mixing commencing, expect that this will lift and scatter especially over northwest IN, though will approach KGYY as it does so. Can't completely rule out a brief period of IFR conditions there, but think the stratus deck will scatter prior to reaching the airport. Otherwise, southeast winds will eventually turn south-southwest across the terminals by midday, under thickening VFR high clouds. Earlier high-res model runs had moved the lake breeze inland through KORD and KMDW later this afternoon, but have since backed off of that solution and it now appears the boundary will remain east of those airports. Farther west, an area of showers and thunderstorms was noted across southern MN/IA and MO. Expectation is that these storms will weaken, with dissipation across southern IA/MO this morning. Scattered storms are then expected to redevelop this afternoon in the vicinity of the MS river, then push east across northern IL. Storms are expected to reach KRFD around 21Z, and the metro terminals 23-00Z, albeit in a gradually weakening state. Storms may produce wind gusts in excess of 30 kts. Winds may become a bit variable behind the storms later this evening, though the gradient would support a westerly direction. The cold front will then bring a wind shift to the north- northwest overnight, with winds eventually turning northeast Sunday morning. An extensive area of MVFR ceilings will likely follow the cold front, lingering into Sunday morning. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago ####018005688#### FXUS62 KJAX 041124 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 724 AM EDT Sat May 4 2024 ...New AVIATION... .NEAR TERM...Today and Tonight... Fog development this morning will be fairly sparse and generally shallow, as elevated southerly flow maintains a somewhat mixed boundary layer. Otherwise, a few showers continue to stream across inland southeast GA early this AM as upper level diffluence enhances downstream from an approaching shortwave just to the west. As that shortwave makes its way slowly eastward, the associated cooling aloft and moistening mid levels will offer a sufficient amount of diurnal instability this afternoon. With those ingredients in play along with the sea breezes, scattered to numerous showers are expected to develop during the mid and late afternoon hours, mainly across interior SE GA and inland NE FL west of Highway 301. Steep low level lapse rates will allow potentially strong outflow winds in the vicinity of pulsing storms. Outflow and sea breeze interaction may lead to a few strong storms this afternoon and evening. Given a fairly weak westerly steering flow, motion of storms today will be outflow driven with a tendency to slowly drift back toward the east coast as they weaken. In addition to a few strong gusts with the more robust convection, PWATs pushing toward the 90th percentile according to sounding climo will allow for localized heavy rain (which will be beneficial given the ongoing dry spell). Convective debris clouds will drift eastward tonight as convection wanes with mostly quiet conditions through the overnight hours. There will be another chance for at least patchy inland fog, particularly in locations that receive a decent amount of rain. Temps today will be modulated by cloud cover and the onshore flow which should keep most of SE GA and coastal NE FL high temp readings in the low/mid 80s while the rest of NE FL warms into the upper 80s to near 90 this afternoon. Another mild night will follow the warm afternoon with lows in the mid/upper 60s except at the coast where onshore flow will keep lows from falling below 70F. For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf && .SHORT TERM...(Sunday through Monday night) Pattern of diurnal convection will continue through Sunday and Monday as a series of mid level short waves pass over the region. Shower and storm developments are expected to be largely scattered with developments becoming more numerous along the diurnal sea breeze boundaries and areas of convergence. High temperatures for this period will be in the upper 80s and lower 90s for inland areas and in the lower to mid 80s along the coastline. && .LONG TERM...(Tuesday through Friday) Predominantly dry weather through the rest of the week as high pressure ridging dominates the weather pattern. Sea breeze winds will be largely pinned to the coast by midweek as prevailing flow shifts to become more out of the southwest due to the positioning of the high pressure axis. Temperatures will rise into the mid 90s as the week progresses with temps potentially reaching record seasonal levels by the end of the period. && .AVIATION... (12Z TAFS) Issued at 717 AM EDT Sat May 4 2024 Amid a more unstable airmass, sea breeze interaction and a passing disturbance will lead to scattered thunderstorms mainly along and east of Highway 301 during the late afternoon (after 20z). Convective impacts are most likely at KGNV; however, outflow may impact terminals with vicinity showers/storms. As storms weaken this evening, the remnant showers will drift eastward and possibly pass across coastal terminals in NE FL. Outside of outflow influence, predominant winds will be east to east-southeasterly around 7-12 knots then trending lighter after 00z. Late in the TAF period expecting better chances for at least MVFR fog/stratus development in the moist airmass at VQQ/GNV after 07Z. && .MARINE... High pressure will remain anchored northeast of the local waters through the weekend. Afternoon sea breeze development will continue each afternoon for the next several days as high pressure repositions further south, shifting winds toward a southeasterly direction early this week. Winds should trend offshore toward the end of next week as a cold front approaches from the northwest. Rip Currents: Risk will only increase to a low-end moderate level as the Atlantic sea breeze develops during the afternoon hours. Otherwise, low surf and light wind will keep risk low. && .CLIMATE... Issued at 219 PM EDT Fri May 3 2024 Daily record Maximum Temperatures at the local climate sites for... Tuesday May 7th...JAX 94/1977...CRG 94/1977...GNV 96/1955...AMG 93/1962 Wednesday May 8th...JAX 96/1959...CRG 93/1977...GNV 97/1955...AMG 95/1962 Thursday May 9th...JAX 96/1962...CRG 93/2008...GNV 95/2011...AMG 95/1962 Friday May 10th...JAX 94/2017...CRG 95/2003...GNV 95/2011...AMG 95/2011 && .PRELIMINARY POINT TEMPS/POPS... AMG 83 65 88 66 / 60 70 50 20 SSI 80 71 82 69 / 20 10 40 20 JAX 85 69 87 66 / 20 20 40 10 SGJ 84 71 85 68 / 10 10 40 10 GNV 88 67 88 65 / 60 60 60 10 OCF 90 67 89 66 / 50 50 60 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ ####018006624#### FXUS63 KLSX 041125 AFDLSX Area Forecast Discussion...Updated Aviation National Weather Service Saint Louis MO 625 AM CDT Sat May 4 2024 .KEY MESSAGES... - Isolated strong to severe thunderstorms will be capable of quarter- size hail and damaging wind gusts today from roughly 2-8pm. - An active weather pattern will bring multiple rounds of severe thunderstorms to portions of the Midwest early to mid next week. Specifics on exact timing, location, and magnitude are still unclear, but confidence continues to increase that the area will experience at least a round of severe weather. && .SHORT TERM... (Through Sunday Night) Issued at 319 AM CDT Sat May4 2024 A shortwave is digging into the Central Plains per recent water vapor imagery, and is aiding in driving ongoing convection along a cold front stretched across that portion of the CONUS. Ahead of this front across the Midwest, surface high pressure is moving eastward, with low-level winds becoming increasingly southerly. However, winds have been calm enough for patchy fog, some locally dense to develop where skies have been mostly clear. This fog will dissipate with the rising sun this morning. This morning, these southerly winds will begin advecting deeper moisture into the CWA ahead of the decaying Plains convection as it enters the area. This decaying convection is not expected to pose a severe thunderstorm threat when it enters portions of central Missouri during the late morning. This afternoon, the increasing boundary layer moisture will yield roughly 1,500-2,000 J/kg of SBCAPE per 00z deterministic guidance and the HREF mean. If convective debris from the morning storms is denser and more widespread, then surface heating and thusly instability will be limited to some degree. Given 0-6 km bulk shear is expected to only be around 20 kts at best, lower instability would greatly reduce the already isolated severe thunderstorm threat. If the previously mentioned levels of instability are realized, then an isolated threat of severe thunderstorms can be expected along the cold front and any lingering outflow boundaries this afternoon as a shortwave passes overhead. Hail up to around the size of quarters and damaging wind gusts are the main threats from roughly 2-8pm. Another shortwave within the southwesterly flow aloft will move out of the Southern Plains and toward the Middle Mississippi Valley tomorrow. Guidance consensus has slowed this shortwave and its surface reflection, leading to much of the area being dry through the day tomorrow. During the afternoon and into the evening, scattered showers and thunderstorms will begin moving into the CWA from the southwest, with the best rain chances (50-70%) remaining along and south of the I-70 corridor through Sunday night. Elmore && .LONG TERM... (Monday through Friday) Issued at 319 AM CDT Sat May 4 2024 Monday will be the start of a multi-day stretch of severe weather potential across the Great Plains and Midwest. Aloft, a trough will broaden over the western CONUS as a shortwave pivots through the Great Plains and into the Upper-Midwest. At the surface, a low will occlude across the Northern Plains as it sweeps a cold front through the Central Plains and lifts a warm front through the Midwest. Guidance consensus is that the cold front will stay west of the CWA during the day Monday, but the warm front will lift northward through the area. Scattered showers and thunderstorms are possible (40-70% chance) with the warm front, but 0-6 km bulk shear of 20 kts or less leads to low confidence in severe weather occurring with the warm front. If severe weather does impact the CWA Monday, it would likely do so late Monday night as decaying convection associated with the Plains cold front moves into the area. The cold front moves into the CWA Tuesday as another shortwave passes through the Midwest along the southeastern periphery of the trough. This will increase 0-6 km shear across the warm sector to roughly 50 kts among SBCAPE peaking around 1,500 J/kg, setting the stage for a potent environment for severe thunderstorms. Given the current lead time, there's still plenty of time for details to chance, such as the phasing of the shortwave, timing of the cold front, and ability of the atmosphere to sufficiently destabilize if there's residual cloud cover from overnight/early morning convection. For Wednesday, the trough reloads as another shortwave moves through the Central Plains and into the Midwest, spawning another surface low that will follow a similar trajectory. In turn, the previous day's cold front will lift northward as a warm front, placing portions of the Middle Mississippi Valley in the warm sector similarly characterized as the one the day prior and leading to another potential round of severe weather. The placement of this threat will be dependent on how far northward the warm front can travel and the timing of the cold front. In the wake of the front to end the week, the upper-level trough will move eastward and place the CWA beneath deep northwesterly flow per ensemble clusters and deterministic guidance. This flow will advect cooler, more seasonable to slightly cooler than normal air into the region. The 25th percentile of ensemble guidance continues to hover right around climatology, building confidence in this outcome. Elmore && .AVIATION... (For the 12z TAFs through 12z Sunday Morning) Issued at 616 AM CDT Sat May 4 2024 A decaying band of showers and thunderstorms is moving toward central Missouri and the KJEF and KCOU terminals. I can't rule out that this convection impacts the terminals earlier this morning, but confidence is low. Additional scattered showers and thunderstorms are expected this afternoon and evening along any remaining outflow boundaries and/or a cold front moving into the area. Other than KUIN where coverage is expected to be greater, the scattered nature of this afternoon/evening convection yields low confidence in direct impacts to local terminals. If showers or thunderstorms are to directly impact terminals, low visibilities, frequent lightning, and sporadic, gusty wind changes are possible. Elmore && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX ####018005756#### FXUS64 KAMA 041124 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 624 AM CDT Sat May 4 2024 ...New UPDATE, AVIATION... .UPDATE... Issued at 624 AM CDT Sat May 4 2024 Showers and isolated thunderstorms continue to develop behind the cold front early this morning. Scattered showers and storms will continue to be possible for a few more hours for the southern row of counties in the TX Panhandle up through Wheeler county. Cloud cover looks to remain in place behind the front today. NBM guidance typically does not do to well with these cooler air masses, so have blended in some cooler guidance for highs for this afternoon. Muscha && .SHORT TERM ... (Today through Sunday night) Issued at 313 AM CDT Sat May 4 2024 A cold front has passed through the panhandles very early this morning. This front is causing some light showers and thunderstorms that will dissipate before the mid morning hours. The winds have shifted to the N post cold front and are currently gusting in the 20s to 30s mph. These winds will remain gusty through the rest of the morning with a slight weakening trend. The passage of the front will shunt moisture to the S leaving the panhandles with just cloudy skies. It wont be till the arrival of a short wave that the moisture will come surging back into the southern panhandles. This when coupled with the instability of the short wave will spark off another round of showers and thunderstorms. The overall dynamics of this system will allow for stronger storms to develop but this would be over more central TX and not in the panhandles. This doesn't mean no strong storms wont happen in the panhandle just that it is a very low chance. While the chance of rain may be high the intensity of the rain has a higher chance of being light as the moisture return wont be long or strong enough for high rainfall amounts. The moisture will have a high chance of sticking across the panhandles through the evening hours but as said before this should only lead to lighter showers and thunderstorms. It wont be until Sunday morning that most of the moisture get shunted out of the panhandles that the showers activity will become very light and isolated. Sunday will also see a stronger low pressure system develop across the desert SW which will begin to impact the southern plains. This would mainly be reflected with an increase in the winds for Sunday and a shift to a southerly direction. These southerly winds will also allow for Sunday to be warmer than Saturday with highs in the 70s. SH && .LONG TERM ... (Monday through Friday) Issued at 313 AM CDT Sat May 4 2024 Some breezy to possibly windy conditions may exist Monday afternoon (wind gusts potentially up to 50 mph) with a possible dryline set up across the far eastern combined Panhandles. Depending on the position of the dryline and upper level support from a potentially negatively tilted trough at H5 some thunderstorms will be possible for only the far eastern combined Panhandles. Have stayed with NBM PoPs for now, around 20 to 30 percent, which may still be too high. This dryline is looking like it may still be well into western OK with no thunderstorms in the Panhandles. West of the dryline breezy and dry conditions are expected and depending on the state of fuels fire weather conditions may exist. The rest of the week looks primarily benign with maybe a couple of weak cold fronts bringing northerly winds and daytime temperatures back down into the 70s for Thu, and upper 60s to lower 70s for Fri. Fri a shortwave trough is progged to approach the far northwestern combined Panhandles with maybe a slight chance PoPs for the far western OK Panhandle. Beyond day 7, on Sat is when this trough may actually bring PoPs to the other parts of the FA. This will be the next potential weather maker after Mon. 36 && .AVIATION... (12Z TAFS) Issued at 624 AM CDT Sat May 4 2024 MVFR to IFR ceilings are forecast through approximately 18z for all sites. VFR conditions should return afterwards til later in the TAF period when precipitation chances return (mainly for KAMA) and low clouds move back in. Have included a PROB30 group for thunderstorm chances at KAMA. When the low clouds move back in, MVFR to IFR conditions are expected. Winds will begin out of the north but will eventually become easterly with gusts of 20 to 25 kts. Winds will gradually decrease over the next 24 hours down to around 10 kts. Muscha && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 68 51 74 57 / 20 50 20 10 Beaver OK 66 47 74 56 / 10 30 30 10 Boise City OK 64 44 75 55 / 10 20 10 0 Borger TX 70 52 78 59 / 10 40 30 10 Boys Ranch TX 69 51 79 59 / 10 40 20 10 Canyon TX 68 51 74 57 / 20 40 20 10 Clarendon TX 67 52 70 58 / 40 60 20 20 Dalhart TX 66 46 75 54 / 10 30 20 0 Guymon OK 66 46 75 55 / 10 20 20 10 Hereford TX 69 52 77 58 / 20 40 10 10 Lipscomb TX 67 50 74 57 / 10 50 30 10 Pampa TX 67 51 73 58 / 20 50 30 10 Shamrock TX 68 52 71 57 / 70 60 30 20 Wellington TX 69 54 72 58 / 60 60 20 20 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...98 LONG TERM....36 AVIATION...05