


Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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558 FXUS63 KIND 101542 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 1142 AM EDT Thu Jul 10 2025 .KEY MESSAGES... - Fog possible early this morning - Mainly dry weather today and tonight - Generally very warm/humid into next week; greatest rain/storm chances through this weekend && .FORECAST UPDATE... Issued at 910 AM EDT Thu Jul 10 2025 Surface Analysis late this morning shows broad high pressure stretching from eastern Ontario, across MI to Indiana and then to eastern TX and the deep south. An MCV and thunderstorm complex was found over southern MN and IA. This system was waning upon its eastward progression toward the high pressure system. Water vapor showed strong subsidence in place over Indiana on the lee side of an upper ridge over the upper midwest. Lower level flow across Indiana was weak and variable due to the broad high pressure system. GOES16 shows clear skies across Central Indiana. A dry afternoon is expected. The subsidence in place along with the broad area of high pressure will provide a mostly sunny afternoon. Forecast soundings support this showing a dry column along with hints of CU development late this afternoon as convective temperatures are approached. Thus a mostly sunny day is expected with highs in the middle to upper 80s. Overall, ongoing forecast appears in good shape. && .SHORT TERM (Today and Tonight)... Issued at 259 AM EDT Thu Jul 10 2025 Skies have largely cleared early this morning as a dirty high pressure filters slightly drier air into the region from the north. Have continued to see a few showers briefly developing over southeast portions of the forecast area. 06Z temperatures were in the upper 60s and lower 70s. The presence of the aforementioned high pressure should aid in a relatively dry day as weak subsidence and a developing capping inversion should keep all but a stray shower or two from developing. The Ohio Valley remains within a sloppy and wavy flow pattern aloft however...which could contribute to additional precip by predawn Friday or perhaps more likely on Friday and into Saturday with the approach of a stronger upper level wave into the Great Lakes. For the short term...the current showers over Jackson County will continue to drift southeast and are likely to not last long. The bigger issue through daybreak is the potential for areas of fog to develop with stagnant flow through the lower levels and remnant moisture present within the near surface layer. To this point fog has been localized but anticipate further expansion through daybreak before diminishing quickly. Much of the day will be quiet with abundant sunshine...light winds and slightly lower humidity. Model soundings do support diurnal cu development for the afternoon and despite the much drier...subsident layer aloft and the cap noted around 700mb...there is likely to be just enough instability to generate a stray shower or two for a brief period late this afternoon. Most areas will remain dry but this is enough to warrant very low precip chances for a couple hours. Cu will diminish near sunset with mostly clear skies returning for the first half of the night. Another subtle wave aloft will approach the region in the predawn hours and while the bulk of the upper level forcing and deeper moisture will be displaced further north over the Great Lakes...could see a few showers approach the northern Wabash Valley towards daybreak Friday. Leaving a dry forecast at this time with low confidence in this solution coming to pass. Temps...low level thermals support highs relatively similar to Wednesday in the mid and upper 80s. Lows tonight will be in the upper 60s and lower 70s. && .LONG TERM (Friday through Wednesday)... Issued at 259 AM EDT Thu Jul 10 2025 High humidity will continue in tandem with very warm to marginally hot conditions into the middle of next week...as central Indiana finds itself generally south of an somewhat active zonal flow stretched along the Canadian border...yet north of any better- organized portions of the subtropical ridge that will attempt to build into the Midwest next week. Weak boundaries on the very southern tier of waves passing closer to the Great Lakes, will occasionally align closer to the Ohio Valley. Corresponding light W to NW flow, which will be most prominent around the Sunday-Monday timeframe should promote slightly milder readings peaking near the mid-80s, and perhaps an overnight falling to the mid-60s for a portion of the region. Otherwise upper 80s should be the rule through the long term, with several days around 90F closer to the Ohio Valley. Maximum afternoon heat indices should be highest on Friday and Saturday, in the mid to upper 90s, courtesy of higher dewpoints above 70F...and also Wednesday ahead of the long-awaited Canadian cold front. Daily opportunities for diurnally-driven convective scattered showers and at least isolated storms will continue...with perhaps more numerous coverage of showers when northern stream waves approach the CWA both over the weekend and perhaps again at the end of the long term ahead of possibly noticeably milder air. Associated non-zero wind shear will introduce the potential for a few strong storms Friday night, especially N/W of Indianapolis... before the period`s best opportunity for stronger storms, late Saturday as a small short wave passes, and then late Sunday when lift from the associated boundary may combine with decent wind shear. Expect any TRWs Monday-Tuesday to be a less-organized, typical midsummer type. Greatest threats from most storms will be lightning, torrential downpours, and localized flooding...with a few stronger cells this weekend perhaps capable of producing minor damage. && .AVIATION (18Z TAF Issuance)... Issued at 1142 AM EDT Thu Jul 10 2025 Impacts: - VFR this period. Discussion: Surface high pressure stretching from Ontario across Indiana to TX and ridging upstream aloft will provide VFR conditions this TAF period. Diurnal cumulus is expected this afternoon and again on Friday afternoon as convective temperatures are reached. CU will diminish in the evening as heating is lost. Forecast soundings keep a dry column through the area this afternoon and tonight along with a mid level inversion which will inhibit tall CU growth. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Puma SHORT TERM...Ryan LONG TERM...AGM AVIATION...Puma