550 FXUS63 KIND 170741 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 241 AM EST Tue Jan 17 2023 .Short Term...(Today and tonight) Issued at 241 AM EST Tue Jan 17 2023 * Low cloud cover will move back into the area today, with this and cold advection leading to nearly steady temperatures over much of the area except the far south, where some limited warming should occur. * Strong low level flow will promote gusty winds today. Low pressure is centered over Wisconsin this morning, moving steadily east/northeast. The triple point is moving through central Indiana, to be quickly followed by the cold front. Remnant drizzle/showers will come to an end rapidly in the next few hours. Some clearing of skies is occurring in the dry slot behind the front, but this will be temporary this morning as low cloud cover associated with the upper low expands back into the area today. There will be a fairly sharp cutoff to the southern extent of the sky cover, and this is a source of uncertainty for today's forecast. Cold advection will be ongoing much of the day, and the cloud cover will further limit any insolation to counteract this, so expect temperatures nearly steady throughout the day, especially across the northern half or so of the area. This required some downward adjustment to NBM temperatures. Low to mid 40s appears likely north/northwest for highs, with low to mid 50s across the south/southeast, where some limited sun and warming is likely. Strong low level flow in the wake of the cold front, along with steep low level lapse rates under a developing subsidence inversion, will promote gusty winds today. BUFKIT momentum transfer progs suggest a few gusts approaching 30KT may be possible at times, with the strongest gusts north, and gusts in the low to mid 20KT range common. Gusts will weaken in typical diurnal fashion this evening as boundary layer mixing subsides. Cloud cover is likely to persist across much of the area into tonight, although mid and high cloud will likely replace dissipating low cloud. This will limit diurnal cooling along with the rapid onset of warm advection yet again ahead of the mid week system. Blend temperatures appeared too cool as a result and were adjusted upward - expecting mid to upper 30s for lows across the area. && .Long Term...(Wednesday through Monday) Issued at 241 AM EST Tue Jan 17 2023 * Active pattern with multiple chances for precipitation * Locally heavy rainfall possible far south Wednesday night * After another warmup on Thursday, cooler, but still above normal temperatures, will continue afterward Wednesday into Thursday... Deepening upper and surface lows will impact the area through this period. On Wednesday, the morning will likely be dry for much of the area, but as a low level jet approaches from the south, isentropic lift will begin to ramp up across the area during the afternoon. Enough moisture will work north during the day for likely PoPs southwest by the end of the day and chance PoPs northeast. The 60kt low level jet will continue to bring lift and moisture into the area Wednesday night. Integrated vapor transport and precipitable water values will be near their climatological maxima. The occluded front will move through the area, with the triple point with the warm and cold front moving through southern Indiana. Plentiful moisture and forcing will lead to categorical PoPs all areas Wednesday night. With the warm front remaining across southern Indiana, the focus for locally heavy rain will be near and north of the front. At the moment, that area looks to be near or not too far south of the far southern forecast area. One caveat though, is that convection along the cold front to the south could rob moisture. QPF numbers are down from previous model runs as well. Nevertheless, will continue to mention locally heavy rain in the Hazardous Weather Outlook. Best instability will remain south of the area in the warm sector. so any severe weather should remain out of central Indiana. Wrap-around moisture behind the lows will move in on Thursday, mainly in the afternoon behind the dry slot. Will keep some chance PoPs around, mainly north. Temperatures will climb Wednesday into Wednesday night, and then perhaps some more on Thursday in the dry slot before the colder air arrives and brings falling temperatures in the afternoon. Breezy conditions will develop as well. Friday and Saturday... High pressure will bring dry conditions and cooler temperatures during this period (highs mainly in the 30s, lows mainly in the 20s). Sunday into Monday... An upper shortwave, as well as a surface trough extending northwest from a surface low in the southeastern USA, could bring some precipitation to the area. However, questions remain on the path and timing of the system, so confidence is low. Will just go with some chance PoPs, with PoPs ending for now by Monday afternoon. Highs will warm into the upper 30s to middle 40s. && .Aviation...(06Z TAF Issuance) Issued at 1206 AM EST Tue Jan 17 2023 Impacts: * IFR/low end MVFR ceilings improving overnight before returning to MVFR during the day Wednesday. * Drizzle and a few lingering showers early. * Southwesterly-westerly wind gusts 18-22KT during the day Wednesday. Discussion: A low pressure system is currently moving through the Great Lakes, with the triple point moving through central Indiana. Widespread low ceilings ahead of the boundaries appear likely to clear out significantly in a few hours, with just some scattered mid cloud likely. With the onset of diurnal heating Wednesday, expect mixing to produce both wind gusts of 18-22KT and the redevelopment of MVFR ceilings across most of the area except perhaps BMG. Some lingering drizzle and a few showers are possible early in the period, mainly at IND, before the area dries out. This will likely be the only significant obstruction to visibility, although will have to monitor for rapid fog formation depending upon how quickly we clear out overnight. && .IND WATCHES/WARNINGS/ADVISORIES...None. && $$ Short Term...Nield Long Term...50 Aviation...Nield