Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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568 FXUS63 KIND 110142 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 942 PM EDT Mon Jun 10 2024 .KEY MESSAGES... - Clear and chilly tonight - Warming trend beginning Wednesday, highs near 90 for Thursday - Low chance of showers/storms Thursday Night into early Friday && .FORECAST UPDATE... Issued at 942 PM EDT Mon Jun 10 2024 Cumulus have dissipated this evening, leaving clear skies. Skies will remain clear to mostly clear with perhaps a few cirrus at times. Winds are diminishing with loss of mixing, and this trend will continue as high pressure builds in. Dewpoints are crashing in the western forecast area with the high moving in. Values are in the lower 30s. Dewpoints will lower elsewhere as the high moves in, but the lowest readings will remain in the west. The clear skies, lessening winds, and dry air will allow for a quick drop in temperatures this evening. Adjusted hourly forecasts to match this. Low temperatures in the 40s still look good though. Wouldn`t be surprised though if the favored cold spots dipped to around 40. && .SHORT TERM (This evening through Tuesday)... Issued at 233 PM EDT Mon Jun 10 2024 Unseasonably cool day in progress across the region as a thick stratocu deck has mitigated much warming through early afternoon with many spots across central Indiana in the upper 50s and lower 60s as of 18Z. A breezy northerly wind has only added to the late September-early October feel to the air this afternoon. A wave aloft passing through the back side of the unseasonably strong upper trough across the northeast states has been the feature largely responsible for the axis of stratocu draped over our forecast area this afternoon. The wave will shift off to the east by late afternoon with the parent trough focusing across New England by late Tuesday. Ridging at the surface and aloft will take over across the Great Lakes and Ohio Valley...and this will begin the upward trend in temperatures that will culminate with the hottest air of the season into the region possibly as early as late this week...and certainly by late weekend into next week. The back edge of the stratocu is already working into far northern portions of the forecast area and will press S/SE through the remainder of the afternoon with sunshine returning for most of the area prior to the evening. With the late sunset after 01Z now...temperatures will get a late bump which should enable highs into the mid and upper 60s for most locations with lower 70s anticipated over the lower Wabash Valley. This very likely will be the last day with sub-70 degrees highs over parts of the forecast area until sometime in September. Peak gusts may briefly increase once the sun gets back out late day as mixing levels increase but as has been the case the last few days...winds will diminish quickly near or just after sunset. A surface ridge will expand into the region tonight and early Tuesday with model soundings and RH progs both highlighting an influx of drier air and deep subsidence. Skies will go clear this evening behind the stratocu and remain so overnight with light and variable surface flow. As will be discussed in the temperature section below...ideal radiational cooling conditions overnight will set the stage for an unseasonably chilly start to the day Tuesday. The center of the surface ridge will drift into the Ohio Valley on Tuesday with ridging aloft building in as well...creating a picture perfect day for central Indiana highlighted by near full sunshine... light winds and comfortable temps with low humidity levels. The temperatures will keep rising into the second half of the week and that will be discussed in greater detail in the Long Term section below. Temps...as mentioned above...lows tonight will be chilly and a good 15 degrees below normal in many locations. Mid and upper 40s will be common by Tuesday morning but a few of our normal cool spots could slip as low as the lower 40s. Temperatures will recover nicely Tuesday underneath the ridging building in with mid to upper 70s anticipated. && .LONG TERM (Tuesday night through Monday)... Issued at 233 PM EDT Mon Jun 10 2024 Tuesday Night Through Friday. Upper level flow will remain northwesterly Tuesday night through much of the middle of the week as central Indiana remains locked into the periphery of a strong upper level ridge across the Central Plains. Conditions are expected to remain quiet through Wednesday with gradually warming temperatures as the stronger northwesterly flow comes to an end and the surface air becomes more stagnant ahead of a return to southerly flow later into the week. The first shot of precipitation is expected Thursday night into Friday as a cold front approaches the area. There is at least some signal within the models for a storm complex late Thursday night ahead of the front, but this remains very uncertain more than 72 hours out. That being said, most models that do generate a storm complex have it decaying as it arrives to central Indiana if not before. Models tend to decay these systems faster than what ends up occurring, but will need to reassess as we get closer. High temperatures on Friday may easily bust if the cold front is sooner than expected which leads to a wide range of temperature possibilities ranging from the mid 70s to near 90. Saturday Through Monday. The aforementioned ridge of high pressure will gradually shift eastward going into the weekend in the aftermath of the frontal passage. Confidence on the temperatures is low and will be dependent on the final strength of the cold front with models gradually trending towards a cooler solution with highs in the low to mid 80s vs the upper 80s to 90 that were previously forecast. As the ridge continues to move eastward, surface flow will become southerly Sunday night into Monday which should bring a return to the near 70 degree dewpoints with a high likelihood of 90+ degree weather for Monday. Looking further out, there is a potential for more active tropical weather bringing additional moisture to the Ohio Valley towards mid week, but the strength of the ridge overhead should keep the heavy rain to the south. && .AVIATION (00Z TAF Issuance)... Issued at 646 PM EDT Mon Jun 10 2024 Impacts: - No impacts expected Discussion: VFR conditions are expected through the period. A few cumulus will linger at some sites early in the period, then clear skies or patchy cirrus will rule through the remainder of the period. Winds will diminish quickly early in the period then become light and variable into Tuesday morning. West to northwest winds less than 10kt will prevail Tuesday afternoon. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...50 SHORT TERM...Ryan LONG TERM...White AVIATION...50