528 FXUS63 KIND 280710 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 210 AM EST Sun Feb 28 2021 .UPDATE... The SYNOPSIS...NEAR TERM and SHORT TERM Sections have been updated below. && .SYNOPSIS... Issued at 210 AM EST Sun Feb 28 2021 Rain showers are expected this morning before tapering off this afternoon across Central Indiana as a cold front crosses Central Indiana. High pressure is then expected to build across Indiana tonight and persist through at least Wednesday...providing dry weather. Another high pressure system is then expected to arrive in the area for the end of the workweek. This will result in more dry weather along with temperatures above seasonal normals. && .NEAR TERM /Today/... Issued at 210 AM EST Sun Feb 28 2021 Surface analysis early this morning shows low pressure in place over KS/NB. A Warm front extended east from this low across Illinois to Southern Indiana. Radar shows rain showers over southern Illinois and southern Indiana pushing northeast. Water vapor imagery shows SW flow in place over Indiana...with a plume of tropical moisture surging northward across TX to the Ohio Valley. Models suggest favorable lift in place today as several embedded short waves push across Indiana within the moist flow aloft...mainly this morning. 295K Isentropic surface shows good lift in place this morning before tapering off this afternoon as the cold front arrives. Time heights and forecast soundings show a very moist column with excellent lift this morning. Given our latest radar trends this appears quite reasonable. This afternoon with the arrival of the cold front a deep trough digging out of the upper midwest. This along with the cold front will help deflect the moist flow aloft to the southeast and bring an end to our precip late in the day. Again forecast soundings continue to show favorable saturation available as the front passes as HRRR shows a band of precip ahead of the front passing across Indiana late in the day. Thus will trend toward 100 pops today with plenty of factors in play for precipitation. Most of the precip will be in the morning...but a second but briefer round will be expected with the frontal passage. Lesser pops this afternoon...but still likely. Given our expected clouds and rain will trend highs at or below the NBM. && .SHORT TERM /Tonight through Tuesday Night/... Issued at 210 AM EST Sun Feb 28 2021 Models show a deep trough over Ontario aloft pushing eastward tonight resulting in NW flow aloft as strong ridging builds across the western United States. All of the available moisture is diverted eastward with the flow aloft and the associated surface cold front that will have passed. Time heights and forecast soundings show strong subsidence and dry air arriving as large surface high pressure in place over the plains builds eastward across the Great Lakes and Ohio Valley. Thus will trend toward a dry forecast tonight with the expected arrival of high pressure. On Monday through Tuesday night strong ridging aloft remains in place over the western plains. This result in lee side subsidence and strong surface high pressure over the plains and great lakes building eastward through Tuesday night. Forecast soundings remain quite dry through Tuesday night. Thus will trend toward partly cloudy skies and not steer far from the NBM on temps. && .LONG TERM /Tuesday night through Saturday/... Issued at 241 PM EST Sat Feb 27 2021 The long term will start off with an upper wave that will move quickly east across the Ohio and Tennessee Valley area. There is general agreement that any brief widespread rain will be south of the area, and the GFS 12z and GFS trends, especially, would keep it all south of central Indiana. That said, can not completely rule out a few showers Tuesday night, especially over south central sections. Thus, will keep the blend small chance to chance PoPs then. Soundings and low level critical thicknesses support a rain and snow mix assuming there are showers around. The rest of next week through Saturday, looks dry or at least mostly dry due to subsidence under the influence of surface high pressure and a dry column. With limited cloud cover, look for above normal temperatures with highs mostly in the lower and middle 50s. && .AVIATION /Discussion for 280600Z TAF Issuance/... Issued at 1132 PM EST Sat Feb 27 2021 IMPACTS: Sub-IFR conditions in rain will expand into the terminals overnight and continue through Sunday morning. Ceilings will slowly recover to MVFR levels by Sunday afternoon and evening. Wind gusts at 20 to 25kts will develop Sunday afternoon as well. DISCUSSION: Widespread rain is steadily expanding north into the region late this evening as a warm front lifts north out of Tennessee and lower Ohio Valleys. Widespread rain and IFR/LIFR ceilings will arrive from the south over the next few hours. Rain will continue into Sunday morning before shifting east from the terminals by midday. Easterly winds this evening will veer to S/SE overnight with the warm front moving into the area. As a cold front sweeps across the area Sunday afternoon...winds will shift to westerly and become gusty. Despite drier air aloft advecting into central Indiana Sunday evening...a strong low level inversion will linger with more substantial clearing occurring during the predawn hours Monday. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Puma NEAR TERM...Puma SHORT TERM...Puma LONG TERM....Koch AVIATION...Ryan