931 FXUS63 KIND 311801 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 200 PM EDT Fri Jul 31 2020 .UPDATE... The LONG TERM Section has been updated below. && .SYNOPSIS... Issued at 139 AM EDT Fri Jul 31 2020 A pesky frontal boundary near the Ohio river along with a few passing areas of low pressure will result in cloudy and cooler days this weekend...along with chances for rain showers and isolated thunderstorms. Best chances for rain will be on Saturday and Saturday Night. Going into next week, a cooler than normal pattern will move in with small chances for rain during the first half of the week and dry conditions afterwards. && .NEAR TERM /Rest of Today/... Issued at 1056 AM EDT Fri Jul 31 2020 Mostly cloudy skies persisted across much of central Indiana late this morning with more sunshine to the northeast of the Indy metro. 1430Z temperatures were generally in the 70s. Quiet weather will continue for the next few hours as drier air advected into the region from the northeast and the deeper plume of moisture and PWATs has dropped south of the Ohio River. As the afternoon progresses however...low level forcing will increase in an axis across southern portions of the forecast area in response to the approach of the next upper wave and associated surface low over Missouri. Deeper moisture will begin to lift back north as well and this combined with the increases in boundary layer convergence will support an increasing threat for showers mainly south of I-70 focused on the second half of the afternoon. Instability remains paltry through the rest of the day and have kept any mention of thunder out of the forecast. Nudged high temps down a degree or so across the board as well. Despite some locations seeing sunshine this morning...expect cloud coverage to gradually increase across the forecast area for the rest of the day. Zone and grid updates out. && .SHORT TERM /Tonight through Sunday Night/... Issued at 139 AM EDT Fri Jul 31 2020 A mostly cloudy...cool and wet at times weekend is in store. The GFS and NAM suggest the broad trough in place over KY will begin to lift north as the upper low to the west begins to push toward Indiana for Saturday. An associated surface low is depicted to push into southern Indiana by Saturday. As these features arrive on Friday Night into Saturday...Time height sections show a gradual increase of saturation within the column...with best lift arriving by Saturday Night. Meanwhile the GFS forecast soundings show deep saturation arriving late Friday Night into Saturday...with pwats near 1.99 inches. Thus will trend pops at or above the NBM Tonight and Saturday as these features for rain remain in play. Given the expected clouds and rain...will trend lows warmer and highs cooler than the NBM. On Saturday night through Sunday the upper low is expected to pass across Indiana before exiting on Sunday Night. Best forcing with the approaching trough looks to pass on Saturday Night and Sunday as plenty of moisture is continued to be depicted across the area. Forecast soundings continue to show a deeply saturated column with pwats once again over 1.80 inches. Thus will continue with high pops on Saturday night and Sunday as these features pass. By Sunday night the upper low is suggested to depart. Forecast soundings begin to dry out as the upper trough axis exits to the east. Still cyclonic flow will remain in place across the area...but somewhat drier air is depicted within the column along with a lack of forcing. Meanwhile at the surface...weak high pressure is suggested to build across Indiana from the Tennessee Valley. Thus will try to trend toward a dry forecast at that time. && .LONG TERM /Monday night through Friday/... Issued at 200 PM EDT Thu Jul 30 2020 Models and ensembles suggest a frontal system will move southeast of the area Monday night. However, sharp Great Lakes trough will pivot through Tuesday and this supports thunderstorm chances through Tuesday. After that, high pressure will build in behind the departed cold front and support mostly dry weather with below normal temperatures through late next week. && .AVIATION /Discussion for the 31/18Z TAF Issuance/... Issued at 1216 PM EDT Fri Jul 31 2020 Good confidence in mostly VFR conditions through 06z Saturday. However, would not rule out brief MVFR ceilings at KHUF and KBMG to start off and would not rule out brief MVFR or worse in convection after 22z. Then, GFS LAMP and SREF agree in the increasing likelihood of MVFR and worse ceilings toward 12z. Winds away from convection will be northeast mainly 10 knots and less. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...Puma NEAR TERM...Ryan SHORT TERM...Puma LONG TERM...MK AVIATION...MK