204 FXUS63 KIND 201051 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 551 AM EST Sat Feb 20 2021 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 300 AM EST Sat Feb 20 2021 After a few flurries early this morning, a dry day is in store for central Indiana. A chance for a wintry mix returns Sunday afternoon and stick around into Monday, and temperatures will slowly increase through the forecast period. && .NEAR TERM /Today/... Issued at 300 AM EST Sat Feb 20 2021 Early this morning an upper wave is moving through the Great Lakes. This is producing a few flurries across northern parts of central Indiana, with a light dusting of snow possible on the high end. This wave should be off to the east by sunrise, and these flurries/very light snow showers should come to an end. Cloud cover will erode later this morning due to subsidence from the surface high increasing over the area. Weak warm advection will begin as the high gets east of the area, and this along with a decent amount of sunshine today should allow temperatures to climb into the mid 20s to lower 30s, with the snow pack keeping the warming from being fully realized. && .SHORT TERM /Tonight through Sunday/... Issued at 300 AM EST Sat Feb 20 2021 Tonight begins with surface high pressure east of the area and some scattered mid to high level clouds. Winds will increase from the south on Sunday as the pressure gradient across the area increases with high pressure moving from WV to the east coast and low pressure strengthening as it moves from Kansas to eastern IA. This will induce an area of isentropic lift Sunday that will serve to increase cloud cover initially and then bring in chances for precipitation from the west as the upper ridge axis over the area to start the day moves off to the east. An upper wave will be approaching but has trended slower, and thus the forcing for Sunday afternoon will stick mainly to that provided by the isentropic lift and surface warm front. Models differ in how quickly warm air and moisture can get advected in aloft, and thus confidence in precipitation type is still low. Rain and snow both look like valid possibilities, and there is some potential that with the snowpack and cloud cover limiting warming that surface temperatures, while above freezing, will be close enough that surfaces could remain below freezing. Regardless, precipitation chances for Sunday afternoon/evening are lower than previous forecast with onset taking a little longer due to dry air and slower arrival of the upper wave. Chances will increase from the northwest during the late afternoon/early evening, with most of the eastern counties still dry until Sunday night but the northwest getting likely to high chance PoPs in the early evening hours. For temperatures Sunday, think the northern counties will be slower to warm due to the snowpack and the southern counties having better proximity to the warm and moist southerly winds. Mid 30s north with lower 40s south for highs Sunday. && .LONG TERM /Sunday night through Friday/... Issued at 300 AM EST Sat Feb 20 2021 Widespread precipitation will be continuing through the night Sunday night as an upper level trough and associated surface cold front pass through the area. During the overnight hours, the strong WAA from southerly air will begin to be cut off, especially after the frontal passage. Ahead of the front, temperatures and thermal profiles look to be warm enough for rain to be the predominant precipitation type everywhere except for the far northern counties with the WAA being stronger than any evaporative cooling. Antecedent ground temperatures though could be a problem with an 8-12 inch layer of frozen soil across the area. This could lead to ice forming on exposed surfaces along with the snowpack still in place. By the late overnight hours, rain will transition to snow and freezing rain, but accumulations are expected to be little to none as the bulk of the forcing and precipitation will have already moved through by then. For much of the rest of the week, dry and warmer conditions are expected. Model output is suggesting highs into the 50s across the southern counties by Wednesday, but feel that is likely overdone with the snow still on the ground. Will cut temperatures by a degree or 2 across the board through the latter portions of the week when the snow should finally melt. A weak system may be moving through by late in the week, but confidence remains very low of any impacts at this time. Temperatures will generally be near to slightly above normal through the period. && .AVIATION /Discussion for 201200z TAF issuance/... Issued at 545 AM EST Sat Feb 20 2021 IMPACTS: VFR thru the period. Can't rule out isolated MVFR conditions during the first couple of hours. DISCUSSION: High pressure will build over the area today and scatter clouds as it does so. Some isentropic lift will arrive by Sunday morning and this will start to drop ceilings, but at this time they still look VFR until Sunday night. CONFIDENCE: Medium confidence in VFR through midday Sunday. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CP NEAR TERM...CP SHORT TERM...CP LONG TERM....White AVIATION...CP