Area Forecast Discussion
Issued by NWS Wilmington, OH
Issued by NWS Wilmington, OH
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139 FXUS61 KILN 120610 AFDILN AREA FORECAST DISCUSSION National Weather Service Wilmington OH 210 AM EDT Fri Jul 12 2024 .SYNOPSIS... A slow moving disturbance will bring the chance for some showers and storms to parts of the area through Friday. Saturday will be mainly dry, however another system will bring a return of shower and thunderstorm chances to the region for Sunday into early next week. Warmer and more humid air will return to the Ohio Valley late this weekend through early next week. && .NEAR TERM /THROUGH TONIGHT/... Evening update... Lingering showers and isolated thunderstorm activity continues across portions of the tri-state and southwest Ohio. PoPs and temperatures were adjusted to current surface observations and radar trends. Given the upper level trough and moisture across along and west of I-75, maintained a slight chance PoP through the overnight despite the cold-pool air mass currently in place over the region. Coverage will continue to decrease the rest of the evening, but there will likely be a few showers/isolated downpours through the overnight. Previous discussion... Amidst abundant sunshine, interrupted only by some SCT Cu, temps have climbed into the mid/upper 80s for most of the area this afternoon. The main item of interest for the near term period is going to be the approach of a slow-moving midlevel disturbance that will pivot towards the area through tonight. Amidst sufficient moisture in the LLs, there will be enough forcing for some ISO/SCT SHRA, with perhaps a rumble of thunder, to develop and slowly migrate E into the wrn half of the ILN FA (especially EC/SE IN and SW/WC OH) through this evening. Expect this activity to be very disorganized and transient in nature (gusting out very quickly), owing to the incredibly weak wind fields through the column. But there should be just enough overlap of instby (SBCAPE ~750-1000 J/kg) and weak lift/forcing to maintain some SCT convection, especially this evening for locales near and W of the I-75 corridor. This activity could produce brief heavy downpours and perhaps some brief breezy conditions, but likely not much else. The activity should persist well after sunset and may not decrease much in coverage until after midnight. This being said, will maintain at least a slight chance PoP near/W of I-75 through the nighttime to account for the expectation of at least a few SHRA lingering into the predawn hours. Lows tonight dip into the lower 60s (central/south-central OH and NE KY) to the upper 60s near/W of I-75. For areas that receive any appreciable rain through early in the nighttime and are able to briefly clear out late, some patchy fog may be possible given the very stagnant LL environment. && .SHORT TERM /SATURDAY/... Redevelopment of SCT disorganized convection is expected by Friday afternoon as the weak disturbance crawls into nrn IN/NW OH. On the ern/SE flank of the weak midlevel trof/low, an axis of better/deeper moisture will develop near the I-75/I-71 corridors by the afternoon once again, serving as a focus for the SCT SHRA/TSRA activity. Again, expect this activity to be very disorganized and transient in nature, owing to the incredibly weak wind fields/shear through the column. Further to the SE in NE KY and the lower Scioto Valley, coverage of SHRA will likely be much more limited than for locales further to the NW. Although temps will undoubtedly be augmented by clouds/convective coverage/evolution through the daytime hours, highs should generally top out in the upper 80s and lower 90s (warmest temps favored SE of I-71 where the clouds and SHRA will be more limited in coverage). Drier conditions should evolve Friday night as lows dip into the upper 60s to around 70 degrees. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A mid-level short wave interacting with a humid and unstable airmass may trigger isolated thunderstorms in far western locations on Saturday. More pronounced short waves tracking across the Great Lakes could bring a better chance for showers and storms Sunday through Tuesday. The threat for convective activity increases again Wednesday when a frontal boundary is forecast to sag into the unstable airmass entrenched across the Ohio Valley. The front settles farther south and high pressure builds over the Great Lakes on Thursday, suggesting diminishing chances for showers and storms. Hot temperatures in the mid 80s to mid 90s Saturday will rise into the 90s in most locations by Monday and Tuesday in the persistent southerly flow ahead of the boundary. Heat indices over 100 will be possible Monday and Tuesday. Cold advection associated with the boundary will allow upper 70s to mid and upper 80s for Wednesday and Thursday. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... A few showers will continue overnight and have vcsh mention in at KILN where there is the best chance for a shower nearby. Cannot rule out a light shower near KLUK overnight as well. Have some MVFR vsbys with fog at KCVG and KLUK later in the overnight hours. Additional showers and some thunderstorms will be possible on Friday especially during the afternoon hours. Have vcsh mention in at most area TAF sites, however put vcts in at KILN where there is a little higher probability of a thunderstorm nearby. Winds will be light and less than 10 knots through the TAF period. There will be the potential for some additional fog Friday night at the end of the longer KCVG TAF. OUTLOOK...Thunderstorms possible at times Sunday through Tuesday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...KC NEAR TERM...KC/McGinnis SHORT TERM...KC LONG TERM...Coniglio AVIATION...