Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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748 FXUS63 KIND 111740 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 140 PM EDT Tue Jun 11 2024 .KEY MESSAGES... - Sunny and Pleasant this afternoon - Warming trend beginning Wednesday, highs near 90 for Thursday - Chance of thunderstorms Thursday Night - Potential for warmest temperatures of the year to go with high humidity starting Sunday && .FORECAST UPDATE... Issued at 916 AM EDT Tue Jun 11 2024 Surface analysis late this morning shows a large area of high pressure in place over IL and IN. The high was influencing the weather from Ontario to the southern plains states. Cool and light northwest flow remained across the forecast area and dew points were in the pleasant lower 40s. Aloft a strong ridge of high pressure was found stretching from KS to eastern WI and then northeast toward NW Quebec. This was resulting in strong lee side subsidence across Michigan and Indiana. The upper ridge aloft is expected to drift east this afternoon. Meanwhile at the surface, the well organized high pressure system will remain in place across Central Indiana. Thus this will lead to very little overall change this afternoon. Forecast soundings and time heights show a dry column across Central Indiana through the afternoon hours. Thus a sunny afternoon is expected. The cool air mass in place along with light north winds will allow for high temperatures to only reach the middle 70s. Overall, ongoing forecast is on track and only minor changes made to the ongoing forecast. && .SHORT TERM (Today and tonight)... Issued at 301 AM EDT Tue Jun 11 2024 Generally quiet weather expected today as high pressure resides over the region. Surface winds should be fairly light today with variable direction at times. Plentiful sunshine should allow temperatures to rebound quite a bit from morning lows down into the 40s. Temperatures in the mid to upper 70s are likely by the late afternoon. Thin cirrus begins to increase during the afternoon, however, as a shortwave trough approaches from the northwest. Clouds thicken and lower with time this evening perhaps becoming overcast from Indy northward. There may be enough lift to generate a few sprinkles across northern Indiana. Fairly dry air exists at the surface so much of this activity would struggle to reach the ground. Still, if anywhere were to see a sprinkle it would be across our northern counties. Surface winds gradually turn southerly tonight as this system passes through and the surface high moves eastward. This will set the stage for a much warmer day Wednesday. Low temperatures are likely to be a bit warmer Tuesday night/Wednesday morning. A few reasons for this. First, the core of the cold air mass exits eastward with the surface high. Second, cloud cover and modest southerly flow act to limit radiational cooling potential. Nevertheless, below-average readings are still expected. The coolest lows may end up being across our south and southeastern counties since winds will be lighter here and cloud cover will be thinner. Lows in the low to mid 50s are likely across much of the CWA. && .LONG TERM (Wednesday through Monday)... Issued at 301 AM EDT Tue Jun 11 2024 Wednesday Through Friday night. The northwest flow regime will continue aloft through Friday night which will keep it mostly dry. However, models are all keying in on the potential for an MCS to move across central Indiana Thursday night. Corfidi vectors favor a southeast moving complex. Weak surface pressure gradient suggests low level inflow into the system will be minimal, however 40-50 knot mid level jet and veering will support good deep shear. Also, instability, although waning a bit should still be plenty sufficient for thunder. At any rate, it is much too early to diagnose mesoscale details, including cold pool/shear balance but nonetheless the above reasoning supports at least 30-40% PoPs Thursday night. As the surface ridge aligns SW-NE along and south of the Ohio River, temperatures will gradually warm to near 90 degrees by Thursday. Meanwhile, potential cold front passage looks like it will result in Friday being not quite as warm with timing considerations key. Confidence is trending on the not as warm side. Saturday Through Tuesday. The main concern later in the weekend and next week will be the heat and humidity as an upper ridge builds overhead and then shifts east as southerly low level flow returns. Models are implying tropical influx next week which will likely result in dew points approaching 70 degrees to go with afternoon highs in the 90s. With the increased moisture and instability, can not rule out isolated pop ups either, mainly during the afternoon. This time period will need to the be looked at for potential future headlines. For now, will broadbrush it in the HWO and keep a weather story graphic going. && .AVIATION (18Z TAF Issuance)... Issued at 140 PM EDT Tue Jun 11 2024 Impacts: - VFR Conditions are expected this TAF period. Discussion: Surface high pressure along with strong ridging aloft are expected to maintain control of Indiana/s weather this afternoon and evening, producing continued mostly clear skies and light winds. A weak short wave over the northern plains may allow for some high cloud to pass overnight across the northern TAF sites, but any CIGS will remain VFR through Wednesday. Forecast soundings through Wednesday afternoon show a dry column with cumulus chances limited due to a mid level inversion. Thus, this is more support for VFR. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Puma SHORT TERM...Eckhoff LONG TERM...MK AVIATION...Puma