746 FXUS63 KIND 270147 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 947 PM EDT Sat Oct 26 2024 .KEY MESSAGES... - Seasonable temperatures this weekend with breezy winds this afternoon - Near record warmth Tuesday and Wednesday along with wind gusts of 30 to 40 mph - Rain likely for Halloween && .FORECAST UPDATE... Issued at 947 PM EDT Sat Oct 26 2024 Mostly clear skies early this evening along with diminishing winds and a dry atmosphere has allowed temperatures to fall quickly, especially in rural areas. Updated hourly temperatures as needed based on latest trends in observations. However, satellite shows a large area of high clouds moving into the area from the west. This will help slow the temperature falls some. Clouds will diminish late tonight as the high clouds begin to exit. With the clouds moving in, only made some tweaks to the low temperature forecast. && .SHORT TERM (This evening through Sunday)... Issued at 303 PM EDT Sat Oct 26 2024 Beautiful autumn afternoon in progress with sunny skies over the Hoosier State. 18z temperatures were generally in the lower to mid 60s. After the brief shot of rain on Friday expansive high pressure has reasserted itself across the easter Midwest. This has led to a return of the weather we have enjoyed for much of the month: dry with mainly clear skies. The high will remain the dominant feature throughout the weekend maintaining dry conditions with seasonable temperatures. Sunny skies will persist through the rest of the afternoon with soundings showing the presence of deep subsidence overhead. Solid boundary layer mixing has enabled northeast winds to be stead around 10 mph with sporadic higher gusts. Should keep the light breeze through most of the afternoon before dropping off near sunset. A subtle upper level save will track across the region in the NW flow aloft, bringing an increase in high clouds. The cirrus though should remain thin with little impact to temperature falls overnight. The upper wave will pass to our SE with the clouds departing in the predawn hours. Sunday should largely be a carbon copy of today with clear skies but one difference will be lights winds gradually transitioning to a more southerly direction by later in the day as the center of the high moves across the region. As mentioned above, despite the cirrus overnight, not expecting much of an impact to temperatures as decent radiational cooling conditions will enable many locations to fall into the 30s and ensure a frosty start on Sunday. Growing confidence that northern counties will bottom out near 32 degrees with our normal cool spots likely to even drop slightly below freezing. Low level thermals are supportive of highs on Sunday afternoon near readings this afternoon with temperatures ranging from the upper 50s northeast to the mid 60s across the lower Wabash Valley. && .LONG TERM (Sunday night through Saturday)... Issued at 303 PM EDT Sat Oct 26 2024 Monday Through Wednesday... Near record high temperatures around 80 degrees by Tuesday! Surface high pressure over the region Sunday shifts eastward as ridging builds over the Plains. Strong ridging builds in over the Eastern CONUS Monday through Wednesday next week with a tight pressure gradient between a 1030mb high over the Mid Atlantic and a sub-1000mb low pushing through the Northern Plains. The low level jet ramps up to 40-50 kts by Tuesday pumping in moist, anomalously warm air from the Gulf into the region. Ample sunshine and boundary layer heating with strong warm air advection will result in highs well above normal for the end of October. In fact, by Tuesday and Wednesday, highs may approach or reach daily record highs in the lower 80s. In addition to such a warm airmass moving in, deep mixing, a tight pressure gradient, and an intense low level jet will likely result in gusty winds at or above 40 mph Tuesday and Wednesday and potentially Thursday. Will be watching the strong wind potential closely as headlines may be needed later next week. Still watching the Fire Weather potential next week as winds ramp up and fuels remain very dry for this time of year. The good news is that moisture advection should be fairly strong, resulting in rising dew points into the 50s and increasing RH values Tuesday through Thursday. There is a possibility that deeper mixing offsets the moist air advection, bringing down drier air aloft during the afternoon hours each day. Adjusted afternoon Min RH and dew points down to the NBM5th percentile which yields afternoon RH values in the 35-45 percent range Mon, Tues, and Wed afternoons...the driest areas being North Central and NW portions of the state. Will have to watch this threat closely as strong winds and dry fuels may still result in an elevated fire weather risk even if RH values are slightly elevated. Halloween through Early Next Weekend ... Latest guidance continues to show a wet Halloween as a front with a strong LLJ parallel to it moves through during the day on Thursday. Deterministic guidance has trended a little faster with the rainfall, bringing the heaviest rainfall over the state midday. ECAIF and GFSGraphcast still show the potential for light precipitation lingering into the evening hours when many outdoor activities and events may be occurring on Thursday. High confidence exists in a warm and wet forecast for Thursday, with lower confidence on how late the rainfall lingers Thursday night. Rain amounts look to range from around a tenth of an inch to as much as a half inch with the higher amounts being in a slower moving system scenario which is the outlier within the ensemble runs. Dry weather looks likely for Friday and Saturday with temperatures returning to near normal to slightly above normal for this time of year. Longer range guidance continues to hint at additional precipitation chances Sunday into the following week; however confidence in placement of fronts and synoptic systems remains low at this point. The longer range pattern does favor at to above normal temperatures locally. && .AVIATION (00Z TAF Issuance)... Issued at 657 PM EDT Sat Oct 26 2024 Impacts: - None Discussion: VFR conditions are expected through the period. The ground had time to dry out today, so not expecting fog tonight. Otherwise, some high and perhaps mid clouds will move through during the night. A few high clouds may linger on Sunday. Winds will lessen during the night, then southeast winds at less than 10kt are expected on Sunday. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...50 SHORT TERM...Ryan LONG TERM...CM AVIATION...50