Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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332 FXUS63 KIND 010145 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 945 PM EDT Tue Apr 30 2024 .KEY MESSAGES... - Low rain chances late tonight. - Low chance for showers or storms Thursday, additional thunderstorms expected late Thursday into the weekend. - Above normal temperatures expected to continue into next week. && .FORECAST UPDATE... Issued at 945 PM EDT Tue Apr 30 2024 Forecast is in good shape this evening. Skies were mostly clear across central Indiana this evening, but cirrus blowoff from convection west of the Mississippi River was rapidly approaching. The clear skies and dry air has allowed temperatures to cool quickly in favored cold spots. Upped sky cover later this evening into the overnight based on latest trends seen on satellite. The convection to the west will outrun its upper support. Observations and latest soundings indicate the convection will also be moving into an unfavorable environment. Thus, believe that only a few showers will still be around by the time what`s left of the convection reaches central Indiana late tonight. Continued with slight chance PoPs late. Tweaked hourly temperatures and low temperatures based on latest trends, but no significant changes were made. && .SHORT TERM (This evening through Wednesday)... Issued at 257 PM EDT Tue Apr 30 2024 Tonight. Quiet weather is expected for much of the overnight period with the main focus being watching convection across Iowa as it pushes into Illinois towards midnight and gradually begins to weaken. Model soundings show little to no elevated instability as far west as central Illinois with the only fuel for the convective system being driven by the cold pool which even by then will be weakening. Will keep low POPs across the northwestern counties to account for this low potential scenario from 08Z to 12Z. There is much higher confidence in mid level clouds associated with the system to linger and push into the area around the same timeframe and will help to limit the bottoming out of temperatures towards daybreak and keep dewpoint depressions high enough to inhibit fog formation. Lows tonight will range from the low 50s in the east with lower cloud cover to the upper 50s in the west where the mid level clouds will be around the longest. Wednesday. Similar conditions expected for tomorrow except for residual thin high clouds persisting through much of the daytime hours as convective debris from the Plains continues to advect across much of the Ohio Valley. This cloud cover will be thin enough to limit diurnal heating and combined with the wind direction gradually becoming less northwesterly, expect that highs should reach into the low 80s for all but the far northern counties. && .LONG TERM (Wednesday night through Tuesday)... Issued at 257 PM EDT Tue Apr 30 2024 Wednesday night through Thursday... A warm front associated with an approaching surface low will move northward early in the period. Increasing isentropic ascent and moisture could support isolated showers and thunderstorms. However, overall forcing looks relatively weak due to the upper trough axis overhead and most guidance show little to no convective coverage. Will stick with low chance POPs for now given the benign signal for precipitation. Increasing heights aloft and increasing southerly flow at the surface will warm temperatures well into the 80s Thursday. Thursday night onward... Better rain chances are expected late Thursday into Friday as the aforementioned surface low and parent trough move into the region. Stronger forcing and a relatively narrow corridor of deeper moisture ahead of an approaching cold front supports better chances for precipitation. The one caveat is guidance shows the approaching front becoming displaced from the parent trough. This will likely limit overall forcing and rainfall amounts across central IN. For this reason, heavy rainfall does not appear to be a threat at this time. There are additional chances for showers or storms over the weekend into next week, but diverging model solutions limits confidence. Some models show the aforementioned cold front pushing through central IN late Friday into Saturday providing dry conditions while others show the front stalling over the area. Will stick with a blended forecast of low POPs for now given the uncertainty, but there is a chance for dry weather on Saturday. Severe weather is unlikely due to limited instability and deep-layer shear. However, some severe weather risk may materialize early to middle of next week as guidance shows increasing instability and deep-layer shear. Predictability remains low this far out, but will continue to monitor the potential. Warm conditions should continue through the extended though highs may be slightly cooler. && .AVIATION (00Z TAF Issuance)... Issued at 701 PM EDT Tue Apr 30 2024 Impacts: - Winds becoming southerly overnight, then a wind shift to the west and northwest Wednesday afternoon Discussion: VFR conditions are expected through the period. Diurnal cumulus will dissipate early, with some passing mid clouds at times. Late tonight more mid clouds will arrive associated with decaying convection. Isolated showers cannot be ruled out 09-11Z or so. A cold front will move through Wednesday, shifting winds. Some VFR ceilings will occur with the front. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...50 SHORT TERM...White LONG TERM...Melo AVIATION...50