343 FXUS63 KIND 111156 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 756 AM EDT Sun Oct 11 2020 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 159 AM EDT Sun Oct 11 2020 Remnants from Hurricane Delta are expected to push across Kentucky today. Rain with this system is expected to remain south of Indiana...however some cloudiness will prevail across Indiana today. A quick moving cold front will then sweep across Indiana from the plains on Monday afternoon...bringing chances for showers or a thunderstorm. Cooler and less humid air will arrive for Tuesday and Wednesday as high pressure moves into the Ohio Valley. Another cold front passing late in the work week will bring more chances for light rain along with even cooler temperatures. && .NEAR TERM /Today/... Issued at 159 AM EDT Sun Oct 11 2020 Surface analysis early this morning show low pressure associated with Delta remnants over Mississippi. A weak cold front was found stretching across Pennsylvania...across OH and Indiana to Central Illinois. High pressure was found across the Great Lakes. Light NE surface flow was in place across Indiana. GOES16 shows high cloud associated with Delta in place across the south and eastern parts of the state...while some lower strato-cu was found in the wake of the front over Northern Indiana. Models today show the northeast progression of Delta remnants along with the southerly progression of the cold front to the north. Aloft...the remnants were cut off from the main flow aloft...which was a ridge in place over the Great Lakes. Meanwhile within the lower levels...the weak cold front to the north is expected to push slowly southward...keeping much of the moisture associated with the remnants south of Central Indiana. Forecast soundings through the period along with time heights reveal a dry column across the area today. Thus with our sweeping cold front and all of the best moisture associated with the remnants southeast of Indiana...will trend toward a dry forecast today with partly sunny skies. Given our expected cloud cover...will trend highs at or below the NBM. && .SHORT TERM /Tonight though Tuesday Night/... Issued at 159 AM EDT Sun Oct 11 2020 Models remain in good agreement tonight that Delta Remnants will be exiting the region...along with the ridging in place aloft over the Great Lakes. A deeper trough is expected to arrive over the Western Plains states which will be our weather feature for Monday. However...for tonight we will be caught between the departure of the upper ridge and the arrival of the approaching trough to the west. Again time heights and forecast soundings continue to show a dry column overnight with ongoing subsidence. Thus will trend toward a partly cloudy sky and lows at or below the NBM. GFS and NAM then suggest a strong upper trough...slightly negatively tilted...pushing across Indiana on Monday afternoon and Monday Night. A sharp cold front was associated with this system and will push across Indiana on Monday afternoon. Ahead of the front moderate southerly flow looks to be in place allowing dew points to reach upper 50s. Forecast soundings suggest saturation on Monday afternoon with pwats of 1.22 to 1.4 inches. Given our favorable forcing dynamics aloft along with sufficient moisture in place...confidence is high for at least some light measurable precip as the along and ahead of the frontal passage. Thus will trend pops at or above the NBM. Given the lack of full day of heating...will trend highs at or below the NBM. Strong subsidence and dry air arrives across the area in the wake of the frontal and upper trough. Forecast soundings on Monday night dry out with strong subsidence in play and remain dry through Tuesday with unreachable convective temperatures. Quick Pacific flow remains in place across the region in the wake of the trough...limiting moisture and blocking high pressure across the southern states will prevent the arrival of any gulf moisture. Thus have will trend toward mostly clear nights and a mostly sunny Tuesday with temps at or below the NBM given the weak cold air advection in play. && .LONG TERM /Wednesday through Sunday/... Issued at 313 AM EDT Sun Oct 11 2020 The long term will start warm as moderate southerly flow pushes a tropical air mass over the Ohio Valley. A prominent area of subsidence induced dry air will help curtail precipitation chances within this southerly flow on Wednesday. However, by Thursday, a subtle region of enhanced moisture out ahead of an advancing cold front will push through, increasing precipitation chances. Ensembles vary slightly on timing and location of the subsequent low. This along with a small moisture regime is creating uncertainty on when and how much precipitation will fall in central Indiana. For now, expect a 30% chance of showers over most of the region, but this could increase as Thursday nears and confidence increases. Following the passage of Thursday's disturbance, cool dry air will encompass the Ohio Valley. Model progs currently show high temperatures less than 60 on Friday and Saturday. This looks likely given 500mb thickness values below climatological norms for this area. Winds could become gusty at times next weekend as a moderate thermal gradient develops across the Midwest along with probable boundary layer mixing in a mostly sunny environment. A few ensemble members have developed showers late next week within weak shortwaves along the aforementioned thermal gradient. Although, confidence is not high enough to include in the forecast at this time. && .AVIATION /Discussion for 11/12Z TAF Issuance/... Issued at 653 AM EDT Sun Oct 11 2020 LIFR visibilities associated with patchy fog in currently effecting all TAF sites except KLAF. This should begin to lift shortly after 13Z. Underlying IFR and then MVFR broken deck will linger until around 16Z. Another round of MVFR cloud decks look to fill in later tomorrow night. Otherwise, VFR conditions are expected with light winds out of the east. An approaching cold front tomorrow could create gusty conditions, although confidence is not high at this point. && .IND WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 9 AM EDT this morning for INZ030- 036>042-044-045-048-049-051>053-060>062. && $$ SYNOPSIS...Puma NEAR TERM...Puma SHORT TERM...Puma LONG TERM....Updike AVIATION...Updike