Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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381 FXUS63 KIND 010349 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 1149 PM EDT Sun Jun 30 2024 .KEY MESSAGES... - Pleasant and Cool Tonight and Monday. - Heat and humidity returns on Tuesday and continues through Friday. - Rain and thunderstorm chances Wednesday through Friday. && .FORECAST UPDATE... No changes needed to the ongoing forecast with conditions evolving as expected. Wind gusts continue to gradually become less frequent with the boundary layer beginning to stabilize. Expect to see temperatures steadily fall overnight with the clear skies and dry airmass in place with some spots towards Lafayette falling into the upper 40s. && .SHORT TERM (This evening through Monday)... Issued at 257 PM EDT Sun Jun 30 2024 Surface analysis early this afternoon shows strong high pressure in place over MN. This high was extending its influence from Manitoba and Saskatchewan, through the northern plains and building across Indiana and Ohio. Northerly flow was in place across Central Indiana and dew points had fallen to the upper 50s. A moderate pressure gradient was in place across central Indiana as the high was building across the area, allowing for these northerly winds to gust to near 20 mph at times. Aloft, water vapor showed ridging building across the Rockies with northwest flow spilling from the upper Midwest to the Ohio Valley. Subsidence was show in place over Indiana. GOES16 showed some diurnal CU through the Wabash valley, blowing off Lake Michigan. Tonight... Models suggest the strong upper ridging in place over the Rockies will make slow but steady progress eastward tonight and into Monday. This will continue northwest flow aloft along with subsidence. The associated surface high pressure system is expected to push southeast also, with its center reaching Lake Michigan by Monday morning. Forecast soundings remain dry through the night. Any diurnal CU across the area will quickly dissipate with daytime heating loss leading to mostly clear skies overnight. Cold air advection on northeast winds will also continue overnight. This along with falling dew points through tonight will allow lows to fall to the lower and middle 50s at most spots. Monday... Another day of quiet, pleasant weather is expected. The upper ridging will continue steady progress eastward on Monday along with its associated surface high pressure system as it pushes to the eastern Great Lakes. This will result in continued dry easterly flow flowing into Central Indiana. Again, forecast soundings show a dry column. Of note, warmer air to the southwest looks to remain at bay due to our northeast flow. However, that will change by mid west as southerly flow returns then. So summing Monday up, mostly sunny with highs in the upper 70s will be expected. && .LONG TERM (Monday night through Sunday)... Issued at 257 PM EDT Sun Jun 30 2024 An anomalous but fairly low amplitude ridge is taking shape over the southern Plains as of this writing. It should then translate eastward with time, settling over the southeastern states by mid- week. From there, the ridge weakens and a zonal jet pattern with embedded shortwaves sets up over the Midwest and Ohio River Valley. After a cool start to the week with lows in the upper 40s or low 50s Monday morning, a quick rebound is likely by Tuesday with highs in the upper 80s. The primary reason is the aforementioned ridging building in, along with surface high pressure sliding east allowing low-level flow to become southerly. Warm moist advection should then continue for a couple days. Simultaneously, a strong system over central Canada will drag a cold front through the Midwestern US. The front likely reaches Indiana, but stalls out and becomes less defined somewhere over the state. This presents a bit of a forecast challenge as the stalled boundary will act to increase shower/storm chances. These showers/storms and associated cloud cover may complicate temperature forecasts. Showers/storms will also be hard to pin point as forcing is rather nebulous and convection may alter/overturn the lower atmosphere which may affect later rounds of convection. Daily shower and storm chances continue as long as this front is in the area. Wednesday, Thursday, and Friday all contain precipitation chances at or over 50 percent. A drying trend is possible over the weekend, since guidance is more or less on board with the idea that a low pressure system develops to our north on Friday. This system, as modeled, appears strong enough to push a front through the area allowing dry continental air to flow southward. Public Awareness Statement: Storm chances exist before, during, and after the 4th of July holiday. There is a chance that inclement weather interrupts holiday plans. With that said, stay tuned for forecast updates as confidence increases and we refine key details (timing, intensity, etc). && .AVIATION (06Z TAF Issuance)... Issued at 1149 PM EDT Sun Jun 30 2024 Impacts: - None. Discussion: A slight veering to more easterly wind direction this morning is expected. Wind speeds will be a bit less than yesterday. VFR conditions will prevail. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...White SHORT TERM...Puma LONG TERM...Eckhoff AVIATION...BRB