Area Forecast Discussion
Issued by NWS Des Moines, IA
Issued by NWS Des Moines, IA
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408 FXUS63 KDMX 071145 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 645 AM CDT Sun Jul 7 2024 ...Updated for the 12z Aviation Discussion... .KEY MESSAGES... - Scattered showers/storms today into tonight. - Isolated/Scattered afternoon convection expected Monday into Wednesday. - Warming late in the forecast as western ridge edges toward the Midwest. && .DISCUSSION... Issued at 403 AM CDT Sun Jul 7 2024 Spotty convection remains over portions of central Iowa this morning as low level moisture transport remains directed into the state early this morning. There has been some locally heavy rainfall with areas near Tama and Marshalltown over an inch. CAMs continue to have isolated/scattered convection into the morning in southern and central Iowa as the low level flow remains directed into the state along with weak instability. Meanwhile, another shortwave drops through the Dakotas and into Nebraska today. This helps to bring another round of lift into the state by this afternoon into tonight. Instability climbs with MUCAPEs above 1000 J/KG by early afternoon with convection expanding as the wave approaches. Some of the 06Z CAMS have indicated the potential for higher wind gusts, particularly in the southeast where there are slight inverted-v soundings. Localized heavy rainfall is also possible but the overall threat for increased flooding or flash flooding remains relatively low given the progression of the bulk of the activity later today into tonight. The broad upper trof remains in place into the early portion of the week as Beryl comes ashore on the Texas coast and heads northeast. The trof axis is expected to be nearly overhead on Monday with daytime heating providing some weak instability by afternoon. This should support some isolated convection during the peak heating hours over the north half to two-thirds of the state. Temperatures remain below normal with extensive cumulus field developing by afternoon as well. Similar conditions exist on Tuesday as the remnants of Beryl move into the lower Midwest and toward the Ohio River Valley although the coverage is expected to be less given generally less forcing. By Wednesday, both GFS and Euro indicate a decent shortwave dropping south toward the state which should encourage the development of afternoon convection once again. Some transition in the pattern is anticipated by late in the work week with the upper trof finally lifting northeast and upper ridging in the western United States expanding east into the Plains. Warmer air is expected to push back into Iowa by Friday and into next weekend with readings likely heading back towards the 90s. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 645 AM CDT Sun Jul 7 2024 Morning convection to impact KDSM and KOTM as it passes across southern Iowa with local MVFR to IFR conditions in and around thunderstorms. Otherwise, widespread VFR conditions are expected today for much of the area. Scattered thunderstorms develop this afternoon and persist into the evening with MVFR to IFR conditions once again in and around the thunderstorms. There may be some wind gusts of 35+kts near the storms as well. Patchy fog may also develop toward the end of the period. && .DMX WATCHES/WARNINGS/ADVISORIES...None. && $$ DISCUSSION...Cogil AVIATION...Cogil