####018006140#### FXUS61 KILN 040547 AFDILN AREA FORECAST DISCUSSION National Weather Service Wilmington OH 147 AM EDT Sat May 4 2024 .SYNOPSIS... Repeated rounds of showers and thunderstorms are expected through the weekend along with muggy conditions. Additional thunderstorms are possible into the middle of next week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... A weak shortwave remains just upstream of the area, providing just enough forcing for some slow-moving showers to persist this evening. The flow through the troposphere is rather light, with nothing above 25 knots until reaching about 400mb and higher. The 00Z KILN sounding is nonetheless somewhat moist, with a precipitable water value of 1.37 inches. This will make for a mild night, with clouds and moisture keeping temperatures from falling too much from their current values in the 60s. Lows in the lower to mid 60s are expected. There may be a very gradual downward trend in shower coverage over the next few hours, but recent model runs do suggest some additional development in the southern ILN CWA (particularly the Cincinnati area) after 10Z. PoPs will thus be focused mainly on the southern part of the area at around daybreak, before precipitation is expected to become a little more widespread with heating tomorrow afternoon. Previous discussion > Light shower activity may continue late this afternoon/early this evening in the unsettled and weakly unstable environment across the Ohio Valley. While a few thunderstorms cannot completely be ruled out prior to sunset, persistent cloud cover and light rain earlier today has kept instability to a minimum. For the overnight, a weak cold front will attempt to drop in the from the north before stalling over northern Ohio. At most, only expecting a few degree temperature drop as some northeasterly flow tries to develop. However, winds could end up mainly remaining light and variable overnight since weak pressure gradient stays over the region. Some shower chances persist tonight and forecast lows are generally in the 60s. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... A weak stalled front is expected to lift north of the area on Saturday. Warm, humid conditions will be in place as southerly flow redevelops leading to highs near 80 during the afternoon. Instability should accompany the muggy conditions Saturday afternoon/evening bringing the chance for showers and thunderstorms. If a weak shortwave does end up moving through on Saturday, fairly widespread shower and thunderstorm coverage could develop. Severe chances remain low since shear is weak and DCAPE remains moderate to low in the moist, saturated sounding. Locally heavy downpours are likely since PWATs will be high. Additionally, brief gusty winds are possible in the strongest storms in the this summer-like setup. Shower/storm chances continue on Saturday night due to the possible development of an upper level shortwave and the approach of a cold front to the northwest. Brief, locally heavy rain remains the biggest threat since instability and shear are weak. Southwesterly winds persist along with warm and muggy conditions. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... A wet period is indicated as persistent moisture advection couples with waves of low pressure. Relatively slow moving systems will allow showers to linger, with brief dry interludes separating batches of showers. Precipitable water remaining above an inch will be feeding the showers. For Sunday, the first wave of low pressure will be tracking to the Great Lakes, resulting in widespread showers and a few thunderstorms. Much the same can be expected for Monday, though most showers may shift south, closer to a disturbance over the Southern Appalachians. A relative lull in precipitation is forecast for Tuesday as high pressure builds in between disturbances. Two more potent waves of low pressure could impact the region on Wednesday and Thursday. There should be a better chance for severe thunderstorms as stronger winds enhance storm strength and structure. Showers and thunderstorms may linger on Friday as another disturbance crosses the Appalachians. Temperatures are likely to stay above normal through the long term, with some fluctuation with respect to advection around weather systems. Highs will generally be in the mid 70s to low 80s Sunday through Thursday, before readings slip to the upper 60s to mid 70s on Friday under a modest decrease in geopotential heights. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... Isolated to scattered showers will continue to lift slowly northeast and perhaps become a bit more numerous through the morning hours as mid level short wave energy lifts up across the Ohio Valley. Cigs are quite variable early this morning, ranging from LIFR in spots to MVFR and VFR across much of the rest of the area. As the lower levels continue to moisten up, think we will see an overall downward trend in cigs as we progress through the pre dawn hours so will generally allow for prevailing MVFR with some tempo IFR conditions. Areas of MVFR to locally IFR vsbys restrictions will also be possible through mid morning. As we head through late morning and into this afternoon, prevailing VFR conditions will return. However, as we destabilize through the day, periods of showers and embedded thunderstorms can be at time this afternoon. This activity should begin to taper off from the west late in the day and into this evening. OUTLOOK...Thunderstorms are possible at times each day from Sunday through Wednesday. MVFR conditions are possible Sunday morning and Monday morning. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Campbell NEAR TERM...Campbell/Hatzos SHORT TERM...Campbell LONG TERM...Coniglio AVIATION...JGL ####018003792#### FZPQ50 PGUM 040547 SRFGUM Surf Zone Forecast for the Mariana Islands National Weather Service Tiyan GU 347 PM ChST Sat May 4 2024 .SYNOPSIS...There will be a moderate risk of rip currents along east facing reefs for the next several days. The low risk along north facing reefs increases to moderate starting Sunday, as north to northeast swell enters the region. $$ GUZ001-MPZ001>003-042100- Guam-Rota-Tinian-Saipan- 347 PM ChST Sat May 4 2024 36 hour Surf Zone Forecast for the Marianas from 600 PM Saturday through 600 AM Monday .TONIGHT (6 PM TO 6 AM SUNDAY)... Rip current risk.....Moderate *. Surf Height North facing reefs............2 to 4 feet. East facing reefs............4 to 6 feet. South facing reefs............1 to 3 feet. West facing reefs............1 to 3 feet. Swell/Period Primary swell................East at 2 to 4 feet. Primary period...............8 seconds. Water temperature Satellite estimates..........82 to 84 Degrees. Coastal Winds............East at 10 to 15 mph. .SUNDAY AND SUNDAY NIGHT (6 AM TO 6 AM MONDAY)... Rip current risk.....Moderate *. Surf Height North facing reefs............3 to 5 feet. East facing reefs............4 to 6 feet. South facing reefs............1 to 3 feet. West facing reefs............2 to 4 feet. Swell/Period Primary swell................East at 2 to 4 feet. Primary period...............8 seconds. Secondary swell..............North at 2 to 3 feet. Secondary period.............10 seconds. Maximum afternoon heat index...........Around 99. Coastal Winds............East at 10 to 15 mph. .OUTLOOK...Surf will build an additional 1 to 2 feet along north and east facing reefs Tuesday as the largest northeast swell enters the region. Tide information for the next 36 hours... At Apra Harbor, Guam... High tide 2.2 feet at 4:15 PM Saturday Low tide 0.5 feet at 10:36 PM Saturday High tide 2.6 feet at 5:14 AM Sunday Low tide 0.7 feet at 11:38 AM Sunday High tide 2.3 feet at 5:35 PM Sunday Low tide 0.7 feet at 11:32 PM Sunday High tide 2.7 feet at 5:45 AM Monday At Rota Island... High tide 2.0 feet at 4:12 PM Saturday Low tide 0.5 feet at 10:30 PM Saturday High tide 2.5 feet at 5:11 AM Sunday Low tide 0.7 feet at 11:32 AM Sunday High tide 2.2 feet at 5:32 PM Sunday Low tide 0.7 feet at 11:26 PM Sunday High tide 2.5 feet at 5:42 AM Monday At Tinian Island... High tide 1.5 feet at 3:26 PM Saturday Low tide 0.3 feet at 9:57 PM Saturday High tide 1.8 feet at 4:31 AM Sunday Low tide 0.5 feet at 11:00 AM Sunday High tide 1.5 feet at 4:53 PM Sunday Low tide 0.6 feet at 10:46 PM Sunday High tide 1.9 feet at 4:57 AM Monday At Tanapag Harbor, Saipan... High tide 1.8 feet at 4:33 PM Saturday Low tide 0.4 feet at 10:35 PM Saturday High tide 2.3 feet at 5:13 AM Sunday Low tide 0.4 feet at 11:36 AM Sunday High tide 1.9 feet at 5:50 PM Sunday Low tide 0.6 feet at 11:25 PM Sunday High tide 2.3 feet at 5:40 AM Monday * Low Risk of rip currents - Strong currents can still occur near jetties and reef channels. Always have a flotation device with you in the water. Moderate Risk of rip currents - Wave conditions support stronger or more frequent rip currents. Always have a flotation device with you in the water. High Risk of rip currents - Large waves will produce strong rip currents, especially along narrow reefs and beaches. If caught in a rip current, swim parallel to the beach rather than against the current. $$ ####018005760#### FXUS64 KSJT 040547 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 1247 AM CDT Sat May 4 2024 ...New AVIATION... .SHORT TERM... (This evening through Saturday) Issued at 204 PM CDT Fri May 3 2024 ...Severe thunderstorms expected again this afternoon and evening... A very moist and unstable airmass persists across the area again this afternoon. A dryline is located across far West Texas, with a residual outflow boundary bisecting the forecast area from northwest to southeast. Strong to extreme instability exists across the area per latest SPC mesoanalysis, with MLCAPE's 3500-4500 J/kg. Deep layer shear is not particularly strong (0-6 km shear around 25 kts) but sufficient for supercells and intense updrafts given the degree of instability. As of 2 PM, visible satellite imagery already shows an agitated cumulus field across western portions of the Big Country and northwest Concho Valley. Latest HRRR develops convection across this area by 21Z (4pm local), with storms expanding in coverage and tracking east across the area during the evening hours. Very large to possibly giant hail, damaging winds and a few tornadoes will be possible. As storms progress eastward with time, the main hazard will transition to damaging winds, although large hail will still be a concern. In addition to the severe threat, precipitable water values near 1.5 inches will support torrential downpours, which may lead to some localized flooding. The airmass will remain very moist and unstable again for Saturday ahead of a weak cold front and a shortwave trough approaching from the west. Models still show fairly widespread thunderstorm development across West Central Texas by afternoon along the weak front, which should be situated across the Big Country. Thunderstorms are expected to expand in coverage by late afternoon and early evening. There is yet another risk for severe storms tomorrow, primarily south of the surface cold front and maximized across western portions of the Concho Valley and farther west across the Permian Basin, where SPC now has an enhanced risk. A slight risk exists across the remainder of West Central Texas. Shear is expected to be stronger tomorrow, especially during the evening hours, which will support tornadoes, some possibly strong within the enhanced risk area. Otherwise, large hail, damaging winds and isolated tornadoes are possible mainly through the evening hours, with damaging winds becoming the main threat overnight as storms push eastward with time. Heavy rainfall is again possible tomorrow afternoon/evening, which may result in some localized flooding. && .LONG TERM... (Saturday night through next Friday) Issued at 222 PM CDT Fri May 3 2024 By early evening Saturday, numerous showers and thunderstorms will be ongoing across much of the area. The primary points of development will be along a weak front that will be stalled across the region and to our west along the dryline. Eventually, expect the storms to congeal into a slow moving mesoscale convective system (MCS) and slowly move south or southeast across the region. Strong to severe thunderstorms will be possible, with large hail and damaging winds being the main concerns, although a tornado is also possible. In addition, locally heavy rainfall will be possible, especially given the expected slow movement of the storms. Some flooding will be possible, especially in low lying areas, low water crossings, and on roadways. Overnight lows will be in the upper 50s to lower 60s. On Sunday, the remnant cold front will remain in the area, so additional showers and thunderstorms are possible. Most of the activity should dissipate by mid to late evening. Drier and hotter conditions are expected for next week. Highs on Monday will approach 90, with highs Tuesday into the low to mid 90s. The hottest temperatures are forecast on Wednesday with highs approaching the upper 90s in our southern counties. A weak cold front will move into the region Thursday, ushering in slightly cooler temperatures. Highs will be in the 80s across the northern half of the area to the low to mid 90s across the southern half of the area. && .AVIATION... (06Z TAFS) Issued at 1246 AM CDT Sat May 4 2024 VFR conditions currently present across the area. MVFR to IFR ceilings are expected to build back in over the next few hours, impacting all terminals. Some sites, primarily KJCT and KBBD, may see visibility reductions, likely to the MVFR category, overnight into mid morning hours. Skies will start to clear from SW to NE after 15Z tomorrow, though our far eastern sites may not see CIGs lift past high-end MVFR. Showers and storms will be possible yet again during the afternoon and evening hours. They will initially start out more scattered in nature before developing into a more solid cluster of storms. Have given a best guess on timing based on current hi-res trends but this will likely need to be adjusted with future updates. && .PRELIMINARY POINT TEMPS/POPS... Abilene 79 61 78 65 / 80 90 10 10 San Angelo 86 61 79 66 / 60 90 40 10 Junction 88 64 81 67 / 30 80 50 10 Brownwood 80 62 77 65 / 60 90 20 20 Sweetwater 79 61 76 66 / 80 90 10 10 Ozona 84 62 78 66 / 40 90 50 10 Brady 82 62 76 66 / 60 90 40 20 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...24 LONG TERM....Daniels AVIATION...50 ####018007378#### FXUS61 KOKX 040549 AFDOKX Area Forecast Discussion National Weather Service New York NY 149 AM EDT Sat May 4 2024 .SYNOPSIS... High pressure along the New England coast will remain nearly stationary into Saturday. A cold front then slowly approaches from the west on Sunday and moves across the area Sunday night into Monday. The boundary likely stalls to our south Monday afternoon through Tuesday before returning as a warm front Wednesday. A series of frontal waves may impact the area to end the week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Forecast remains on track tonight. A high amplitude upper ridge over the eastern third of the country will be slow to translate east through the first half this weekend. This will keep surface high pressure ridging down along the New England coast and into our area. Expect a light easterly flow to continue with varying amounts of cloud cover. Satellite imagery shows a fair amount of high clouds moving through the upper ridge axis. This could impact temperatures somewhat depending on the opacity. Lows will generally be in the mid to upper 40s, but around 50 for the NYC metro. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... Not much change during this time as the forecast area will remain under an easterly flow at 10 mph or less. Varying amounts of high clouds will filter through the upper ridge over the area on Saturday, which works to the east Saturday night. Clouds will lower and thicken Saturday night with some fog possible toward daybreak Sunday. Warm advection rain on the backside of the ridge, ahead of an approaching warm front, continues to trend slower. Chances of rain Saturday night remain low and mainly after midnight. Temperatures during this time will at or just below normal. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... *Key Points* *An approaching front will bring rain Sunday into Sunday night, which ends early Monday morning. Rainfall amounts average one quarter to one half inch. *The front stalls to our south early next week with limited chances for showers through Tuesday. *Unsettled conditions are likely Wednesday through next Friday, although not a wash out. Several frontal waves are possible, which may bring periods of showers, but timing is uncertain. *Below normal temperatures Sunday should trend back above normal next week. Timing of the potential precip could impact temperatures late in the week. A shortwave associated with a larger upper low over Central Canada will try to break down the highly amplified ridging over the east coast to start the long term. The guidance has continued to show a slower trend to this process with the associated frontal system not moving through the area until Sunday night or early Monday. Rain associated with the front should start in the morning west of the NYC metro and then slowly spread eastward through the afternoon. This continues to look like mainly an overrunning rainfall with little to no elevated instability. Average amounts range from around one quarter to one half inch. The shortwave axis will push offshore later Monday with the front stalled to our south and west. Another highly amplified ridge builds across the Great Lakes in response to a large upper low over the Northern Plains and Northern Rockies. There are conflicting signals in the guidance for whether or not energy will traverse underneath the ridge towards the area Monday night. This potential energy would interact with the stalled front to bring another chance of rain. However, some of the global guidance weakens the energy with the height field becoming suppressed over New England in response to an upper low over the Maritimes. A weak high pressure should build towards New England which should keep any precip, if it were to develop, mainly near the coast closer to the stalled front. Have used the NBM for PoPs with just a low chance near the coast Monday night. A piece of the ridge builds overhead on Tuesday, so this should end up being a mainly dry day. The next forecast challenge will be for Wednesday through the end of the week. The stationary front to our south and west should begin lifting back north as a warm front on Wednesday. The parent low will be associated with the upper low over the Northern Rockies and Northern Plains, but there may be a few waves along the warm front. One of these may be enough to initiate some convection Wednesday afternoon or evening. The upper low then slowly moves east towards the Great Lakes to end the week. Several frontal waves may move across or just south the area keeping conditions unsettled. Timing of these waves is highly uncertain given a late Day 5 through Day 7 forecast, so have capped PoPs off at high chance for now. Sunday will be cool with rain and temperatures in the middle to upper 50s. Conditions should begin rising back above normal next week with temperatures in the 70s most afternoons away from the immediate coastline. Have followed the NBM deterministic, but it should be noted that there is a fair amount of spread in the guidance, especially later in the week due to the potential precip. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... High pressure remains in place through tonight. VFR, although tempo MVFR cigs possible for the NJ terminals before 10z. MVFR develops this evening, lowering to IFR overnight. A shower possible starting late this afternoon, however rainfall doesn't become likely until Sunday afternoon. Light easterly flow or variable in direction through at least 12z, then ESE-SE winds around 10kt through the rest of the TAF period. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Tempo MVFR cigs possible for KLGA and KJFK before 10-12z. Chance that tempo MVFR cigs for KTEB and KEWR do not occur. OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY... Saturday Night: IFR. Chance of showers. Sunday...MVFR/IFR. Showers likely mainly in the afternoon. ESE winds G15-20kt. Monday...VFR. Tuesday... Mainly VFR. Chance of MVFR showers. Wednesday...MVFR or lower with a chance of showers. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Sub-SCA conditions are forecast to start the weekend with high pressure along the New England coast maintaining an easterly flow across the waters. Winds will generally be around 10 kt. Winds and seas should remain below SCA criteria Sunday the middle of next week with a weak pressure gradient in place. There may be an increase in winds closer to 20 kt and seas building to around 4 ft, but conditions are expected to remain below SCA levels. && .HYDROLOGY... There are currently no hydrologic concerns through next week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/DW NEAR TERM...DR/DW/MW SHORT TERM...DW LONG TERM...DS AVIATION...JC MARINE...DS/DW HYDROLOGY...DS/DW ####018009739#### FXUS63 KLOT 040549 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 1249 AM CDT Sat May 4 2024 .KEY MESSAGES... - A dry and cool night is in store with overnight lows in the mid to upper 40s. - Tomorrow (Saturday) will be warm with highs in the upper 70s to lower 80s, and increasing chances (60 to 70%) for showers and thunderstorms in the evening especially across northern Illinois. - Periodic shower and thunderstorm chances next week, with some potential for strong to severe storms Tuesday. && .DISCUSSION... Issued at 200 PM CDT Fri May 3 2024 Through Saturday night: A surface high pressure system continues to meander through the Lower Great Lakes region and is leading to mostly sunny skies, light north to northeasterly winds, and generally pleasant temperatures (at least away from Lake Michigan). With our area on the western flank of the surface high tonight, quiet conditions will prevail. Light winds, clear skies, and a dry airmass will facilitate efficient radiational cooling and allow for overnight lows to fall into the mid to upper 40s. Tomorrow, low-level flow will turn southeasterly and eventually southwesterly as the surface high pulls further away to the east and an upper-level short-wavelength trough approaches from the west. Low- level moisture advection will allow for humid air across central Illinois and Indiana to quickly return northward and into our area by mid-afternoon. Even with filtered sunshine, the advection of a plume of seasonably warm 850mb temperatures near +13C (into which the boundary layer will build) will help boost afternoon highs into the upper 70s to lower 80s. Chances for showers and thunderstorms will increase during the afternoon hours in two apparent waves. The first will be with an axis of remnant convection (originating from the Plains tonight), due to arrive sometime in our area early tomorrow afternoon. An ensemble of CAM guidance suggests the leading axis of showers and storms may outrun the best forcing provided by the upper-level shortwave and an associated cold front lagging to the west, and fight a pocket of dry mid-level air in place across the Lower Great Lakes. As a result, chances for showers and storms appear higher later in the afternoon and toward evening along the cold front as it moves across the area (50 to 70% chance from west to east ahead of the cold front). With the upper-level shortwave and associated jet streak expected to lift northeastward toward the Upper Peninsula of Michigan (e.g. remain somewhat displaced from the instability axis further to the south across our area), any convective cell tomorrow afternoon and evening should behave in a "pulse" like fashion with overall limited storm-scale organization. As a result, the main threats with any storm tomorrow will be locally gusty winds, small hail, downpours, and lightning strikes, similar to yesterday (and consistent with a level 1/5 threat for severe weather). In all, tomorrow looks like another quintessential spring-like day. Coverage of showers and storms will decrease after sunset as the cold front approaches northwestern Indiana. Temperatures behind the front will fall into the upper 40s (northwest) to mid 50s (southeast) early Sunday morning as northwesterly winds become predominant. Borchardt Sunday through Friday: Next week is shaping up to be a fairly wet and active pattern. Starting Sunday, as an upper level low drops southward into Northern California from the Bay of Alaska (more on this later), a surface low over Hudson Bay is forecasted to continue to move east drawing the cold front east out of the forecast area. There may be some lingering showers on Sunday morning, particularly over northwest Indiana, but potentially extending as far back to I-55. However, improving and drier conditions are expected through Sunday. Temperatures are expected in the upper 60s and 70s away from the lake, but with cooler northerly air over Lake Michigan, the immediate shoreline may remain in the 50s. On Monday, the low over Northern California is expected to weaken slightly and passes over the Rocky Mountains. Ahead of of it, another upper level wave will pass over Northern Illinois. Models are disagreeing on the overall strength of the wave. The GFS is leaning deeper with an brief closed low aloft developing, where the Euro and the Canadian depict broader waves. Moisture availability seems limited though over most of the area north of I-80. With some weak lobes of vorticity that pass over, there is a chance for some light showers to pass over, but confidence remains low as it should mostly stay south of the area as temperatures warm back into the 70s, with low 60s on the shoreline. There is fairly good model agreement that the upper level low will eject out of the Rockies over west central Montana overnight Monday into Tuesday morning while deepening. Strong surface cyclogenesis is expected to take place in the Northern Plains on Tuesday; however, where and how the low develops will largely drive what unfolds on Tuesday, and models are wildly disagreeing on that. There is a strong 300 mb jet that will develop just to the south of the upper level low, with its left exit region around or just north of northeastern Illinois, which will could assist in providing additional synoptic lift, though the exact placement of the jet will have to be monitored over time. But even models are disagreeing with the strength of the jet in addition to its exact placement. Regardless, strong mid level steering flow will draw up anomalously large precipitable water values into Illinois with dew points temperatures expected in the low to mid 60s. After a weak boundary pushes through Tuesday morning providing the first chance for rain, temperatures are projected to increase behind the front into the upper 70s and 80s. With better instability, showers and thunderstorms are expected Tuesday afternoon and evening. While models are suggesting the strongest shear and instability a little farther south in Central Illinois and the Ohio River basin, there is the potential for strong to even severe storms locally on Tuesday. By Wednesday, the upper level low over the Northern Plains is projected to eventually start to weaken; however, a positively tilted trough axis will remain over Plains. With persistent southerly warm air advection, there is a risk for another round of showers and storms on Wednesday. Once again though, models are still keeping higher moisture content and stronger instability to the south over the Ohio River Valley as the jet core aloft shifts slightly over Southern Wisconsin. Perhaps the risk for stronger to severe storms will remain south of I-80 on Wednesday, but it will be close enough to be monitored. Beyond Thursday, there is much more uncertainty on exact timing of showery activity. However, both Euro and GFS ensembles are suggesting the upper level trough to continue to broaden and trudge eastward from Thursday through Sunday. With lingering moisture in the area and lobes of vorticity passing around the upper level trough, there could be periods of showers from Thursday through Saturday. It is not expected to be a complete wash out as there should be breaks from the rain at times, but it remains too far out for complete understanding on timing, so the forecast maintained a 20 to 40 percent chance for rain through Saturday morning. DK && .AVIATION /06Z TAFS THROUGH 12Z SUNDAY/... Issued at 1236 AM CDT Sat May 4 2024 Key Aviation Messages: - Low probability for shallow fog through sunrise, mainly away from Chicago. - Scattered showers and thunderstorms likely this afternoon and evening, some of which could produce gusty winds. - Light southeast winds become south-southwest by midday, with possible lake breeze wind shift late afternoon for KORD/KMDW/KGYY. Surface high pressure was centered northeast of the forecast area at midnight. Farther west, an area of weak low pressure was over the central Plains. This low will move east-northeast to the western Great Lakes region by evening, with its cold front moving east of the area late. Light easterly (or variable) winds are expected early this morning, turning southeast around sunrise and then south-southwest by midday. Several recent high- res model runs indicate a southeasterly lake breeze will develop, and may affect KORD/KMDW/KGYY late this afternoon. This return to easterly winds appears to be short-lived however, as an area of scattered showers and thunderstorms are expected to move east across the area later this afternoon and early evening, possibly producing westerly outflow winds of 25-30+ kts as they move into the Chicago metro area toward evening. Thunderstorms would likely be in a diminishing trend as they move into the metro. The cold front associated with this system will bring a shift to northwest and eventually north-northeast winds later in the evening, which would continue overnight. Guidance also indicates a period of MVFR ceilings is possible behind the front. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago