####018008086#### FXUS63 KIND 101857 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 257 PM EDT Fri May 10 2024 .KEY MESSAGES... - Increasing clouds tonight, with a brief period of rain overnight - Breezy on Saturday - Showers and storms return Monday into Monday night - Near normal temperatures for next week && .SHORT TERM (This evening through Saturday)... Issued at 257 PM EDT Fri May 10 2024 Rest of This Afternoon... Cumulus will continue across central Indiana through much of the afternoon. Satellite has been showing some enhanced cumulus as well, so still wouldn't rule out an isolated shower. However, odds remain too low to mention in the forecast. Tonight... Cumulus will dissipate with mainly some patchy mid and high clouds around this evening, with high pressure ridging into the area. Overnight, an upper shortwave will move through. A surface cold front will accompany the shortwave. Moisture will be confined to mainly north of the area, but there will be enough for the system to produce up to around a tenth of an inch in the far north. However, lack of moisture to the southwest should keep the far southwest part of the area dry. Will go with likely PoPs at some point overnight in the north, tapering to dry PoPs in the far southwest. Temperatures will dip into the lower 50s for lows tonight. Saturday... The vast majority of the forcing will be east of central Indiana by the start of the Saturday period (12Z, 8AM EDT). Will only go with some chance PoPs far east through mid-morning. Cold advection will aid in mixing on Saturday, bringing wind gusts up to around 30 mph at times. Some cumulus will form in the cold advection, but skies will still be partly to mostly sunny. Some models are keeping a surface trough across the northeast forecast area Saturday afternoon, with a few even generating rain with it. However, looking at ensembles, these seem like a low probability. Will keep it dry but increase sky cover some in the northeast Saturday afternoon. Even with cold advection, temperatures will peak in the upper 60s to lower 70s. && .LONG TERM (Saturday night through Friday)... Issued at 257 PM EDT Fri May 10 2024 An active weather pattern continues into next week with multiple chances for additional rain and thunderstorms. It won't be a complete washout of a week though with a couple dry days in between systems. While there will be rain and storm chances throughout the extended, the threat for severe weather appears much lower than it has been over the past week. Sunday... High pressure sets up just south of the region late Saturday night while upper ridging builds in through Monday resulting in a brief period of drier and warmer weather across the Ohio Valley. Subsidence under the high in addition to warm air advection through the column will result in a beautiful, warm day across the entire region. Model soundings indicate a well mixed boundary layer and steep low level lapse rates leading to highs well into the 70s and potentially reaching 80 for portions of SW Indiana. Monday through Tuesday... Another warm day expected Monday; however an approaching trough and associated surface low over Kansas will bring the next chance for rain across the region. Increasing moisture advection through the column and lift ahead of the system will result in increasing clouds Monday with rain beginning to develop during the afternoon and evening hours. Currently some discrepancies among guidance with timing of arrival for precipitation with the GFS bringing in rain by early Monday afternoon and the EC holding off until Monday night. Will have to watch how much dry air mixes down to the surface Sunday and how quickly the column saturates on Monday. Historically, models are too quick to saturate the column after a few days of dry weather and bring in rainfall too early at times. This would also affect high temperatures, with a later arrival of rain allowing for more daytime heating. Despite lower confidence in rainfall chances Monday afternoon, high confidence exists in showers Monday night into Tuesday morning as the surface low pushing into Southern Missouri/Illinois on Tuesday. Model soundings show very skinny, elevated CAPE Monday night with better instability values on Tuesday in the immediate vicinity of the surface low. Lightning will likely be few and far between initially with the best chance for any thunder and lightning closer to the surface low Tuesday afternoon in South Central Indiana. Model soundings show PW values rising to between 1.25 and 1.50 inches late Monday night into Tuesday with deep moisture present throughout the depth of the column. The setup supports the potential for pockets of heavy rainfall, particularly on Tuesday with any slow moving convection. Ensemble means show low probability for greater than an inch of rainfall with 90th percentile QPF totals ranging from 1.00" to 1.30" across Central Indiana. It is likely lower resolution guidance is not taking into account the potential for heavier convection. So values over an inch appear certainly probably in this scenario, especially for areas that get repeated heavier showers. South Central Indiana looks to have a better potential for those higher rainfall totals being closer to the low and having better moisture advection and higher instability values. Despite increased clouds, warm air advection ahead of the system will support highs in the 70s on Monday, with the potential for a few areas to near the 80 degree mark if rain holds off until the evening and nighttime hours. Expect Tuesday to be a little cooler in the mid 60s to lower 70s due to more widespread showers and storms. Wednesday through Thursday... Troughing begins to slide eastward on Wednesday while ridging builds back in over the Midwest. With high pressure settling in from the NW Wednesday morning and the trough still influencing weather locally, low stratus may stick around through the first half of the day as moisture is trapped under a subsidence inversion. Expect a drying trend through the day Wednesday persisting into Thursday with highs still near to above average in the low to mid 70s. High pressure centered over Southern Canada and the Northeast CONUS will result in another mainly dry day on Thursday for Indiana. Friday into Next Weekend... Another deep trough and potent storm system is expected to develop and push into the region sometime this weekend bringing another round of unsettled weather conditions. Longer range guidance diverges quite a bit on the exact evolution of the system, timing, and track. Despite lower confidence in details, ensembles have been consistent in showing signals for a strong storm system during this time frame potentially leading to another round of showers and thunderstorms and cooler weather on the backside of it. Will be watching this timeframe closely through the week as details become clearer on the evolution of things and associated impacts. && .AVIATION (18Z TAF Issuance)... Issued at 1253 PM EDT Fri May 10 2024 Impacts: - Northwesterly wind gusts to around 25kt Saturday Discussion: A broken VFR cumulus field will persist this afternoon then scatter out as heating is lost. Mid and high clouds will increase this evening, then as a front moves through overnight an area of rain with lower VFR ceilings will move through. Brief MVFR in rain cannot be ruled out, but odds are too low to include. Clouds will scatter out on Saturday, and winds will become gusty. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...50 LONG TERM...CM AVIATION...50