Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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327 FXUS63 KIND 010709 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 309 AM EDT Wed May 1 2024 .KEY MESSAGES... - Mostly Sunny and Warm today. - Partly Cloudy and mild Tonight. - Low chance for showers or storms Thursday, additional thunderstorms expected late Thursday into the weekend and again early next week. - Above normal temperatures expected to continue into next week. && .SHORT TERM (Today and tonight)... Issued at 307 AM EDT Wed May 1 2024 Synopsis: Surface analysis early this morning shows high pressure in place over eastern KY and eastern TN. Low pressure was found over MN with a cool front stretching south into eastern IA, NW MO and to SE KS. This was resulting in a southerly flow across Indiana. Radar shows convection in place ahead of the front, including over NW IL. Showers were weakening. CI blow off from the convection was spilling over Indiana. Aloft a weak ridge was found over KY and TN, while mainly a zonal flow was seen streaming across the plains to the Ohio valley. Today... Models show the weak short wave generating the convection to the west will push east of Indiana this morning and continuing a diminishing trend. As this occurs, weak ridging aloft is expected to remain over eastern TN/E KY and OH. This will allow for a continued flow of mild Pacific air aloft. Meanwhile at the surface, surface high pressure remaining over Eastern KY will continue to remain in control of the weather across Central Indiana, providing warm southerly winds. After some morning high clouds due to the CI blow off, Partly Cloudy skies will be expected by afternoon as we remain under the influence of the ridging aloft and surface high. Forecast soundings show a dry column, but hint at late afternoon CU development as convective temperatures are reached. Southerly flow and weak warm air advection will allow for high temperatures in the upper 70s and lower 80s. Tonight... Somewhat of a transition is expected tonight. The surface high to the east is expected to drift farther east, while surface low pressure is expected to push into the plains. This continues to keep southerly flow in place across Central Indiana and hint at the formation of a warm front setting up over central and northern Indiana. Aloft the ridge axis is suggested to push farther east, allowing for more of a southwest flow to stream into Indiana. Some weak forcing is shown to push toward Indiana overnight amid the southwest flow aloft. However forecast soundings fail to show deep saturation at any time, and just hint at the arrival of the warm front within the lower levels. Thus confidence for rain late tonight is very low and will try to not include this in the forecast given the limited moisture and very marginal forcing available. Given the warm front across the area, will trend lows toward the upper 50s and lower 60s. && .LONG TERM (Thursday through Tuesday)... Issued at 307 AM EDT Wed May 1 2024 Ridging will be moving out with an approaching troughing system continuing the above normal temperatures and storm chances through the long term period. Thursday will be the warmest day of the long term and is forecasted to get near the daily record highs. The first main wave of this system comes at the end of this week followed by a short wave or two before another large system is expected to bring more storms at the end of the period. Depending on how long the warm front associated with this first upper wave stick around, Thursday may see some precipitation with the the northern counties being the most likely to be impacted. The best chances for PoPs with this end of week system will come on Friday ahead of the associated cold front. Still seeing a variety of solutions when it comes to timing, so confidence remains on the lower end as to when it will rain, but regional models are trending towards the Euro time of arrival solution rather than the faster and more expansive GFS solution. On the other hand, the GFS and regional models are also faster to move the front and rain through than the Euro. For now keeping with guidance on PoPs that include a longer timeframe for PoPs due to these timing discrepancies. While timing is unsure with the late week system, still expecting a break in rain at some point Saturday before a short wave brings more showers and storms late Saturday into Sunday and there will likely be another brief dry period before the next upper low moves in early next week. At this time, not expecting severe weather associated with any of these systems but multiple rounds of rain may bring brief localized flooding and renewed and prolonged river flooding. && .AVIATION (06Z TAF Issuance)... Issued at 1230 AM EDT Wed May 1 2024 Impacts: - VFR conditions are expected this TAF period. Discussion: VFR conditions are expected through the period. High pressure southeast of Indiana, over eastern KY and eastern TN, will dominate Indiana`s weather through this TAF Period. A few showers and isolated TSRA were found over NW IL. HRRR suggests these will continue to weaken upon approach as the atmosphere over Indiana was less favorable for convection. Still have kept a vcsh mention at HUF and LAF for 10Z-12Z when there is potential for these to reach the Wabash Valley. Confidence on that is low. Forecast soundings on Wednesday remain dry with attainable afternoon convective temperatures with an inversion in place aloft. Thus have trended toward some bkn cumulus during the afternoon hours. When daytime heating is lost after 02000Z, CU will dissipate and VFR will continue. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Puma LONG TERM...KF AVIATION...Puma