Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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680 FXUS63 KIND 081919 CCA AFDIND Area Forecast Discussion...CORRECTION National Weather Service Indianapolis IN 319 PM EDT Sat Jun 8 2024 .KEY MESSAGES... - Scattered showers possible this evening into tonight, a few storms possible over northwest portions of central IN - Dry conditions expected Sunday through at least Wednesday - Cooler Sunday night-Monday night...moderating to near-90F highs for Thursday-Saturday && .SHORT TERM (This evening through Sunday)... Issued at 300 PM EDT Sat Jun 8 2024 Current satellite/radar observations show relatively quiet weather conditions over central IN this afternoon. Rain chances will begin to increase this evening as a cold front moves in. Low-level theta-e advection ahead of the front and low-level convergence should allow for scattered showers to develop with perhaps a few thunderstorms. Convective coverage will likely remain limited this evening into tonight due to the surface wave or associated cold front outpacing the parent trough. Rain chances remain capped at no greater than 40% for this reason. The greatest rain chances are across W/NW counties closer to the surface wave. Low rain chances will persist early in the overnight hours as the front continues to progress southeastward. Drier air then filters in late promoting quiet conditions. Expect winds to become N/NW once the front passes which should help keep temperatures near or slightly below normal. Weak surface high pressure settles in for Sunday allowing for quiet weather conditions to persist. While cool N/NW flow will be in place, less cloud cover will warm temperatures well into the 70s. A few locations could potentially reach the 80F mark. There is a low chance for light rain across far southern counties as a disturbance moves through Southern Indiana and Kentucky. Most guidance shows precipitation remaining near or south of the Ohio River so this appears unlikely. && .LONG TERM (Sunday night through Saturday)... Corrected at 319 PM EDT Sat Jun 8 2024 Sunday Night through Wednesday... Mainly dry conditions will prevail through the first half of the week while overseeing steady moderation from sub-seasonal readings to near normal early June warmth by the Wednesday timeframe. A series of upper waves tracking generally along the US-Canada border, will start with a larger trough over east-central North America through Monday...followed by an amplified yet short wave ridge on Tuesday...and then a couple of smaller, more northern-tracking short waves during the remainder of the mid-week. At the surface broad Canadian high pressure will be building into Indiana at the start of the long term, cross the region Monday night...and settle from the Tennessee Valley to the Mid-Atlantic, along a more zonal pattern south of the passing mid-week northern waves. Despite adequate sunshine through the early week, light/moderate NNW breezes will hold temperatures a solid 5-10 degrees below normal through Monday night, with some typically cooler spots probably not reaching 70F on Monday. Widespread 50s Sunday night will set-up colder conditions Monday night where clear and nearly calm conditions will promote lows around 45-50F outside of the Indianapolis Metro. Distinct moderation to follow for Tuesday- Wednesday with slightly above normal marks by Wednesday afternoon from modest southwesterly flow...reaching the mid-80s for most locations under scattered clouds. Lack of stronger return flow should at least help to hold off summer-like/moderate humidity until at least Wednesday night of not Thursday. Thursday through Saturday... Above normal, mid-summer type warmth/heat with corresponding moderate humidity will be the rule starting on Thursday under the retracted upper flow...and a building ridge over the High Plains directing several days in the upper 80s to around 90F. Not the greatest confidence in temperature forecast for any given day as the pattern may support weak waves rippling down the east side of the building, western ridge and into the Midwest. Nonetheless moderate certainty in several above normal days. A small threat of potential showers/storms will also exist given the increased theta-E, albeit limited by an at-times capped profile and generally weak forcing. The normal first 90F+ day at Indianapolis is June 19...and the normal max/min at Indianapolis for the long term is 82/62. && .AVIATION (18Z TAF Issuance)... Issued at 1214 PM EDT Sat Jun 8 2024 Impacts: - Isolated to scattered showers possible this evening and early overnight - MVFR ceilings possible late tonight and early Sunday - Sporadic gusts to around 20kts possible this afternoon Discussion: Thick mid level cloud deck across the entire area early this afternoon with pockets of light showers and sprinkles moving east. Showers should largely diminish by or shortly after 18Z with clouds lingering through the afternoon and evening. A large area of clearing over central Illinois already is in the process of filling in and expect only a brief period of filtered sun at best. Southwest winds will become sporadically gusty through the afternoon then diminish towards sunset. Isolated to scattered showers are likely to redevelop later this evening as a weak cold front slides southeast into the region. The approach and passage of the boundary will have a greater impact on ceilings however...as model soundings show moisture becoming trapped beneath a boundary layer inversion. This will translate to a period of MVFR stratus from late evening into the predawn hours before ceilings lift Sunday morning. The passage of another series of convective clusters through the Ozarks and into the Tennessee and lower Ohio Valleys overnight and again on Sunday will likely keep mid and high cloud coverage up a bit across the southern half of central Indiana into Sunday. The expansion though of a subtle surface ridge should promote decreasing clouds into the afternoon with northwest flow. && .IND WATCHES/WARNINGS/ADVISORIES...None. && $$ SHORT TERM...Melo LONG TERM...AGM AVIATION...Ryan