714 FXUS63 KIND 100604 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 204 AM EDT Wed Oct 10 2018 .UPDATE... The SYNOPSIS...NEAR TERM and SHORT TERM Sections have been updated below. && .SYNOPSIS... Issued at 204 AM EDT Wed Oct 10 2018 Look for rain as strong cold front will push across Central Indiana today and tonight. Showers and thunderstorms are expected along and ahead of the front. Much cooler high pressure is expected to build across Indiana in the wake of the front. This will bring dry and much cooler weather through the end of the work week and into the weekend. More showers will be possible on Sunday as another front is expected to move swiftly across the state. && .NEAR TERM /Today/... Issued at 204 AM EDT Wed Oct 10 2018 Surface analysis early this morning shows strong low pressure in place over western Iowa. A cold front extended south from the low...crossing eastern Kansas and eastern Oklahoma. Water vapor imagery shows a plume of tropical moisture ahead of the front over the Mississippi river valley. National Radar Mosaics shows a stream of showers and storms associated with said plume of tropical moisture...stretching from Louisiana to Wisconsin. Warm SE flow was in place across Central Indiana with dew points in the 60s. GOES16 shows cloud cover across Illinois increasing and spreading toward Indiana. The GFS and NAM suggest the cold front and associated tropical plume will advect east...pushing across Central Indiana this afternoon. Excellent dynamics in play today for rain including a strong upper short wave and a strong cold front poised to push across the state. Forecast soundings show deep saturation by afternoon with pwats that over 2 inches. This is reflected of the very moist air mass that is in place across Central Indiana. Forecast soundings show mainly a moist adiabatic column...thus instability appears rather limited...but a few rumbles of thunder cannot be ruled out. Also given the strength of the cold front and marginal shear available an isolated severe storm cannot be ruled out. best chances for rain will be in the afternoon and evening...when the plume of tropical moisture and associated cold front is expected to pass. Thus will trend pops toward categorical at that point. Look for high temperatures to be achieved shortly before precipitation occurring...which should be near the middle of the day. Evaporative cooling along with the subsequent cold front will thereafter result in falling temperatures. Will stick close to the forecast builder blends for highs and will not exceed MAVMOS. && .SHORT TERM /Tonight through Friday Night/... Issued at 204 AM EDT Wed Oct 10 2018 The GFS suggests the surface cold front will be exiting Indiana near 00Z...and cyclonic lower level flow will be in place in the wake of the front. Forecast soundings continue to show a saturated column at 00Z...but that rapidly chances toward 06Z as strong subsidence and drying within the wake of the front take over. By 06Z forecast soundings show nearly a dry column as do the time heights as forcing is lost. Thus may keep some chances for pops...particularly across the eastern parts of the forecast are for a few hours after 00Z...but will quickly trend the forecast toward dry by 06Z. As for temps will trend lows close to the model blend values. Fall arrives in earnest on Thursday and will persist through Saturday. Strong Canadian high pressure is expected to build and settle across the Ohio valley through Saturday. Forecast soundings show a very dry column. Aloft a quick moving short wave is expected to push through the flow on Friday Night...but with little to no moisture available...thus should result in mainly a few clouds. Thus will trend this period toward partly cloudy days and mostly clear nights. Given the very cool air being introduced to the blends for the first time...will trend temps generally at or below the model blend. Coldest air of the season...lows in the mid 30s possible on Friday and Saturday Mornings. && .LONG TERM /Friday night through Tuesday/... Issued at 321 PM EDT Tue Oct 9 2018 An upper trough will move through Friday night and usher in colder temperatures than we've seen yet this season with lows in the mid to upper 30s. Confidence is about par for a long term period, with some timing differences in each model run but overall similar patterns. This brings potential for some patchy frost to develop late during the overnight hours with light winds and clearing skies. Brief upper ridging will then move through for Saturday into Saturday night. A frontal system will then move closer on Saturday night and bring rain chances back into the area. The front will stall as a surface low moves along it and thus rain chances will remain in the forecast through Monday. High temperatures look to be in the 50s throughout the long term, with lows in the 40s Saturday night and Sunday night and then back into the 30s Monday night. && .AVIATION /Discussion for the 10/06Z TAFs/... Issued at 1142 PM EDT Tue Oct 9 2018 VFR through the first several hours of the period, before MVFR ceilings and visibilities move in with showers and embedded thunderstorms Wednesday morning. Ceilings will steadily deteriorate Wednesday morning and may get close to or drop into high end IFR briefly. Fluctuations are likely as is usually the case. Winds will generally be southeasterly early, becoming more southerly with time. Gusts tomorrow into the upper teens are likely at times. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Puma NEAR TERM...Puma SHORT TERM...Puma LONG TERM...CP AVIATION...Nield