Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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334 FXUS63 KIND 010133 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 933 PM EDT Fri May 31 2024 .KEY MESSAGES... - Showers and isolated thunderstorms Saturday - Warming trend going into next week with periodic storm chances - Long range 8-14 day outlook trending toward below normal temperatures && .FORECAST UPDATE... Issued at 933 PM EDT Fri May 31 2024 Cirrus continues to filter in across the region this evening as low pressure moves into southwest Missouri. 01Z temperatures were largely in the upper 60s and lower 70s with a light southeast wind. Making subtle adjustments for tonight and the first half of Saturday based on some of the newer model data trickling in which further slows the arrival of rain to the predawn hours Saturday in the lower Wabash Valley with the rest of the forecast area not likely to see any showers until later in the morning and across eastern counties quite possibly not until the afternoon. The abundance of dry air still present across the region will be slow to depart with the deeper plume of advecting low level moisture highlighted by dewpoints at or above 60 likely to hold off across much of the forecast area until well after daybreak. For the rest of the overnight...expect a steady increase in mid and high level clouds as the surface wave makes slow progress eastward. Adjusted temps slightly as lows will range from the lower and mid 50s over northeast counties to the lower 60s in the lower Wabash Valley. && .SHORT TERM (This evening through Saturday)... Issued at 251 PM EDT Fri May 31 2024 Early this afternoon, upper air data and satellite was depicting a high amplitude ridge from Hudson Bay to the Tennessee Valley. Meanwhile, at the surface, broad high pressure was found over the eastern Great Lakes and upper Ohio Valley and broad low pressure was over the Southwest. Satellite was showing only some high clouds overhead. Southeast winds, filtered sunshine and subsidence has allowed temperatures to climb to the middle and upper 70s. Hi-Res soundings were showing a very dry column in place. Meanwhile, 305K isentropic analysis is introducing strong upglide overnight and into Saturday. Although it will take awhile for the atmosphere to saturate down, eventually low condensation pressure deficits support rain chances starting up after 06z. More than likely due to the dry column in place, it will be more like after 09z and starting over southwestern sections. Soundings later Saturday morning support widespread rain which will continue through the afternoon. Instability progs are showing very weak to no instability, so lightning strikes should be few and far between. Warm advection and increasing cloud cover suggest overnight lows will only be in the upper 50s to lower 60s. Meanwhile, the thick cloud cover and rain will likely limit temperatures to the lower 70s Saturday afternoon. && .LONG TERM (Saturday night through Friday)... Issued at 251 PM EDT Fri May 31 2024 Saturday Night Through Sunday. By Saturday night the surface low will be moving across the northern half of the state with precipitation expected to continue through much of the night but the bulk of the forcing will be just ahead of the low associated with the strengthening LLJ rain coverage and intensity should decrease through the night. Some precipitation will likely continue into the daytime hours on the backend of the system but with the low being more broad and not quite as strong, the flow on the backend isn`t quite as robust as we saw earlier in the week. The low stratus clouds will begin to dissipate by the early afternoon with residual cu persisting through the late evening hours. Monday Through Friday. Forecast confidence quickly begins to fall off next week as the flow aloft becomes much more stagnant and the pattern becomes more driven by mesoscale factors that are very uncertain this far out. There does look to be at least occasional showers and thunderstorms which will generally be diurnally driven so will focus POPs highest in the 18Z to 00Z timeframe. Surface flow will generally remain southerly through the week which will keep temperatures just above normal with much higher dewpoints of mid to upper 60s. A more deeply wrapped up low looks likely towards the end of the week which should bring a relief from the more humid air and warmth. The pattern favors the potential for a few storm complexes across the Midwest but there is low confidence that any will impact central Indiana. Going into the latter portions of the week confidence is increasing in colder temperatures moving back in with a strong upper level low across the Great Lakes region bringing northwesterly flow at the surface and aloft with lower confidence on the track and strength of the low. && .AVIATION (00Z TAF Issuance)... Issued at 621 PM EDT Fri May 31 2024 Impacts: - Rain developing Saturday morning - IFR conditions by mid to late Saturday afternoon - Small risk for embedded thunderstorms Discussion: Cirrus continues to steadily overspread central Indiana ahead of low pressure moving into the Ozarks this evening. Clouds will continue to thicken and lower overnight but dry air will remain prevalent through the boundary layer courtesy of southeast flow. A few light showers may make it to KHUF near daybreak but most rain will hold off until later in the morning. The surface low will track into the lower Ohio Valley on Saturday with a progressively deeper surge of moisture advecting into the region from the south. Showers will spread east through the mid and late morning with widespread rain for the afternoon and evening. MOdel soundings and RH progs show lower levels becoming saturated late day with ceilings likely to dip quickly to MVFR and eventually IFR within the steadier rainfall. Cannot rule out a few rumbles of thunder but overall instability is minimal and will not mention at the terminals. Winds will remain southeast through much of the forecast period and may become sporadically gusty Saturday afternoon as the surface wave approaches. && .IND WATCHES/WARNINGS/ADVISORIES...None. && $$ UPDATE...Ryan SHORT TERM...MK LONG TERM...White AVIATION...Ryan