Area Forecast Discussion
Issued by NWS Wilmington, OH

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543 FXUS61 KILN 251039 AFDILN AREA FORECAST DISCUSSION National Weather Service Wilmington OH 639 AM EDT Tue Jun 25 2024 .SYNOPSIS... An unsettled pattern, with several chances for showers and storms, will persist through Wednesday before drier conditions briefly return for Thursday and Friday. However, rain and storm chances return once again on Saturday, with drier conditions favored for Sunday into early next week. Near to above normal temperatures are expected for the foreseeable future. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Tranquil conditions will continue locally through daybreak, although they won`t last too much long, unfortunately. As the sfc high shifts to the E of the OH Vly through the morning, abrupt moisture return will begin to nose back into the area from the W into the afternoon hours. This will occur following the S/W ejecting E through the Great Lakes region through daybreak, which has prompted the development of a stout and increasingly-well organized MCS now across WI, which will track to the ESE into MI and far nrn IL/IN/OH through mid morning. As this occurs, we may see a few WAA-induced WAA develop along a N-S oriented axis across EC IN and WC OH, primarily between about 13z-17z, but this should be of little consequence to the convective evolution through the rest of the day. The forecast later into the daytime becomes incredibly complex, and will be largely dictated by convective evolution throughout the time period. As the primary S/W pulls to the NE of the OH Vly late morning into early evening, taking with it the better forcing, the remnant outflow/boundary stretching back to the W should serve as a focus for renewed convective development by early afternoon across nrn IL/IN/OH. This will occur as activity attempts to redevelop closer to the pool of better moisture/instby collecting/advecting across IL/IN and far wrn OH. Confidence continues to increase in the potential for redevelopment, to a certain extent, of a E-W oriented axis of TSRA along the stale MCS boundary. This reason for this is partially because of the delayed timing (compared to previous fcsts), which will allow /just enough/ time for a surge of higher theta-e air (better LL moisture content) to nose into areas near/W of I-75 into early afternoon. The latest guidance suggests that a very narrow ribbon of SB-instby will develop immediately ahead of the southward-progressing outflow-driven storm activity into mid-afternoon, supporting locally gusty to damaging winds with the strongest cores. This will especially be the case for areas near/W of I-75 and especially near/W of I-71 with the better instby to work with than for locales in NE KY or the lower Scioto Valley. The better SB instby should pinch off with eastward extent. The rapid jump in temps/humidity/SB instby early/mid afternoon in the wrn third of the ILN FA may be enough to prompt and maintain a more concerning severe threat into the local area than was originally expected. At this juncture, it is likely that additional clusters or complexes of storms will develop within the trailing MCS boundary, spreading to the SSE through the local area between about 17z-23z (N-S). Given the robust destabilization efforts underway near/W of I-75/I-71 prior to storm arrival, it is certainly worth mentioning the potential for widespread gusty to locally damaging winds this afternoon into early evening. A high DCAPE environment amidst favorable LL/deep-layer thermodynamic fields and potential for aggressive cold-pool driven processes suggests that these storms could be locally intense and persist for quite a long time, even in the absence of any synoptic-based forcing or source for lift. Feel that the SPC slight risk on the SWODY1 in our west is well- warranted and needed.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... The fcst for this evening through Wednesday following the expectation for daytime convection becomes even muddier, unfortunately. It seems plausible, given the latest data, that there will be a several hour lull in pcpn locally following the afternoon/early evening storms. This lull should stretch past midnight into the middle of the night before additional loosely- organized activity moves back in from the W by/after 06z-09z. The storms tonight are likely to be much more disorganized and not pose such a potential for strong/severe activity. However, any of this activity will bring with it the potential for some lightning and very heavy downpours/localized ponding of water. Coverage of SHRA/TSRA should be on the increase toward daybreak and beyond, but there are quite a few uncertainties in how things will unfold on Wednesday in terms of a hazardous-weather perspective. There is likely to be better forcing moving E through the region Wednesday morning through the daytime, potentially too much so. In fact, in an uncapped environment, the focus for any organized storms appears rather nebulous (except along the SE- moving front very late in the day), potentially leading to a somewhat "grungy" environment characterized by poor LL (and midlevel) lapse rates. This would suggest that storms/updrafts may struggle to become particularly intense, with much more in the way of widespread storms, with only a few becoming strong to severe briefly. There will be slightly better LL and deep- layer flow fields to work with Wednesday, but the poor deep- layer lapse rates and slightly less unstable environment cast some doubt onto the coverage of /severe/ storms. Rainfall through the period will be highly-variable, both in time and space, but would expect that some spots will pick up 1-2 inches between now and Wednesday evening, especially with the anomalously-high PWATs expected region-wide for the daytime Wednesday. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... The frontal boundary will be moving through the CWA at the start of the extended period and any lingering showers/storms will be moving southeast out of the region. Post frontal air on Thursday indicates high temperatures in the low 80s with dew points in the lower 60s... will feel much drier than previous days. Weak ridging and surface high pressure take over and we`ll have mostly sunny skies with some CAA cu. Overnight lows in the upper 50s/ low 60s as we head into Friday. Friday we see yet another disturbance on the horizon and return southerly flow helps pump warm, moist air back into the region. Mid and upper level clouds increase and highs reach back into the upper 80s. Precip from this system looks to move into the region sometime Friday into Saturday as the warm associated with this disturbance lifts through the area. This keeps temperatures on the warmer side, with highs in the upper 80s/ low 90s for Friday and Saturday. As of right now, the cold front looks to push through Saturday sometime and given the amount of moisture pumped up/ robust looking nature of the parent low pressure, wouldn`t be surprised to see some stronger storms move through, but time will tell. Ridging and high pressure move into the region on the backside of this system and Sunday we dry out again. Temperatures cool slightly in the post cold-frontal air and highs reach the mid 80s. The high looks to remain in control for at least another few days, so anticipating dry conditions for the start of the working week. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/...
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Some mid/high clouds, courtesy of convective debris blowoff upstream, are filtering in from the W, with thickening cloud cover expected through early afternoon. For the daytime, there continues to be quite a bit of uncertainty in how things will unfold, especially when attempting to focus on one specific location through time. More specifically, there remain some uncertainties in both timing and structural integrity of this axis of SHRA/TSRA which will quickly move into the local area by early afternoon, especially as the environment will be increasingly unfavorable for maintenance of stronger/severe storms with further E/SE extent. That being said, do think there will be a broken linear feature that eventually migrates to the S through the local area mid/late afternoon (17z-23z), bringing with it some SHRA/TSRA and some gusty wind potential (as the storms will be outflow dominant). But pinpointing impacts at one location through the daytime will be somewhat challenging. The activity should weaken with SE extent, with the best organization/maintenance/intensity favored for KCVG/KLUK where the better instby will be positioned by late day. Of course, abrupt reductions in both VSBYs and CIGs and wind speed/direction will be favored in the strongest activity. After 00z, there may be a brief lull that evolves locally before additional clusters/loosely-organized SHRA/TSRA move back into the local area between 06z-12z Wednesday. Light southerly winds will increase to 12-15kts as they go more out of the SW by/past 15z, eventually subsiding toward the end of the period as light (generally 5kts or less) southerly flow resumes. OUTLOOK...Thunderstorms possible Wednesday and again on Saturday.
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&& .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...KC NEAR TERM...KC SHORT TERM...KC LONG TERM...CA AVIATION...KC