738 FXUS63 KIND 202057 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 357 PM EST Sat Feb 20 2021 .UPDATE... The SYNOPSIS...NEAR TERM and SHORT TERM Sections have been updated below. && .SYNOPSIS... Issued at 355 PM EST Sat Feb 20 2021 One more very cold night tonight, near 15F, will be followed by readings holding in the 30s for the Sunday-Monday period, surrounding a rain/mix event Sunday night. The remainder of next week will feature near to slightly below normal temperatures and generally dry conditions before chances of rain on Saturday. && .NEAR TERM /Rest of Today and Tonight/... Issued at 357 PM EST Sat Feb 20 2021 Temperatures have risen past the 30F mark for many locations along and south of I-70 this afternoon, including a report of 37F in Bricknell...making it the first day above freezing in two weeks for many southern counties. The light winds and bright skies responsible for this return to less-unseasonably cold conditions...have been courtesy a strong, broad dome of surface high pressure, currently settled over the Ohio Valley. Fair weather will continue through dawn Sunday as the high drifts eastward, although the light winds will allow for one more very cold night across central Indiana. Partly to mostly clear skies will continue this evening for most locations, although considerable cloudiness will return pre-dawn as the next weather system approaches. Overnight lows will range from low teens across the northeast to upper teens along the southwest. The normal low is now 26F. && .SHORT TERM /Sunday through Monday Night/... Issued at 350 PM EST Sat Feb 20 2021 A short wave trough and corresponding weak, yet strengthening surface low, will cross from the lower Missouri Valley Sunday to the southern Great Lakes by Monday morning...bringing thickening clouds over the ridge that blessed much of Indiana with decent late-winter sunshine Friday-today. Nevertheless strengthening SSE breezes will finally bring the entire region above freezing, as gusts reach 20-25 MPH Sunday afternoon north of I-70. A light to moderate, yet rather brief, mixed precipitation event will then follow from late day Sunday to pre-dawn Monday. Confidence is building that surface air temperatures will be above 32F for nearly all of the event...yet cold surfaces, courtesy the current 10"-thick frost depth, will present the threat of slick pavements where untreated. Precipitation type should be primarily rain amid the increasing southerly low-level flow...however along and north of I-70 a wet snow/rain mix is expected at the onset through Sunday evening...as well as as the rain tapers off from west to east before dawn Monday. Winds will gust across all of the CWA to 20-25 MPH from the south...and then the southwest as the system's front crosses Indiana before dawn. Precipitation totals in the 0.15- 0.30" range are likely, with any snow accumulations Sunday evening limited to a thin coating. Guidance has trended slightly warmer during the event's peak Sunday evening through the middle of the night...with most of the region at least briefly reaching the upper 30s amid the rain. Nevertheless re-freezing will certainly be a concern early Monday morning as temperatures fall back near 32F with thick frost just beneath the surface. The remainder of the period will see a return to dry conditions, and actually among seasonable temperatures for the first time in over two weeks. A brisk zonal-type pattern aloft will maintain moderate breezes from a generally-WSW direction, gusting to 15-20 MPH, especially north of I-70 where the overriding gradient will be stronger. mostly cloudy skies are expected to linger Monday before scattering out Monday night. High temperatures for the period will be the mid to upper 30's, with low temperatures in the low 30s for most locations both mornings. && .LONG TERM /Tuesday through Saturday/... Issued at 203 PM EST Sat Feb 20 2021 Mainly Dry weather with near seasonable temperatures will be expected this period. ECMWF shows a zonal flow in place from Tuesday through Thursday morning. A weak cold front looks to pass as a dry boundary as little moisture appears available along with little to no upper support. On Thursday a quick moving upper trough arrives aloft as strong ridging is building aloft over the plains. Meanwhile at surface...large high pressure is suggested to be building across the plains and spreading east beneath the trough. Thus elements for precip are not lining up and will continue a dry forecast. High pressure and ridging then builds across the area for Friday...resulting in more dry weather. By Saturday the NBM is trying to add some pops based upon return flow ahead of an approaching cold front. Confidence in that is low at this time due to timing. Have kept the low chance pops for now. && .AVIATION /Discussion for the 201800Z Tafs/... Issued at 1231 PM EST Sat Feb 20 2021 IMPACTS: VFR cigs are expected this Taf period. DISCUSSION: High pressure in place over Kentucky and Ohio will provide southerly winds across the Taf sites this period. GOES16 shows some higher cloud streaming across the TAF sites...however forecast soundings show attainable convective temperatures with CCL bases above VFR levels. Thus will expect some SC development this afternoon as temperatures rise. Ongoing warm air advection tonight will continue to promote mainly mid and high cloud development tonight. CONFIDENCE: High confidence for VFR this afternoon and tonight. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...AGM NEAR TERM...AGM SHORT TERM...AGM LONG TERM....Puma AVIATION...JP