Area Forecast Discussion
Issued by NWS Des Moines, IA
Issued by NWS Des Moines, IA
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546 FXUS63 KDMX 042333 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 633 PM CDT Sat Apr 4 2026 ...Updated for the 00z Aviation Discussion... .KEY MESSAGES... - Cool and breezy today. Scattered sprinkles/flurries. - Few area rivers approaching minor flood stage due to rainfall through recent days. See hydro discussion for more details. - Comfortable on Sunday, then cooler to start the week. Pattern turning active through second half of next week. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 248 PM CDT Sat Apr 4 2026 Cool and windy conditions prevail over Iowa today, as increasing surface pressure and cold air advection drive the sensible weather conditions. West northwesterly winds have been around 20 to 25 mph with gusts of 30 to 40 mph common over much of the state. With the steepened low level lapse rates, a shallow unstable layer is present just above the surface, resulting in scattered flurries/sprinkles. A few more prominent showers are possible in northern Iowa through this afternoon and evening, but no impacts are anticipated. The breezy winds will diminish some this evening, but remain light to breezy through the night, especially in northern and northeastern Iowa nearer to the low. Farther south and west, lighter winds will develop overnight. Cool temperatures, light winds and clear skies may introduce the potential for some frost development as temperatures approach their dewpoint early Sunday morning. This will be most likely over far southern and southwestern Iowa, while areas farther north and east will be too breezy for frost. Temperatures then warm under mostly clear skies on Sunday, pushing highs into the mid to upper 50s. Winds will remain light to breezy on Sunday, but not nearly as windy as today, making for a relatively pleasant Easter Day. A weak shortwave aloft will drop through the overall northwesterly flow regime Sunday into Monday. The surface pattern responds with subtle pressure falls, followed by a cold front and another push of cold air advection and high pressure filling into the state on Monday. As this occurs, weak low pressure over Colorado and the Texas/Oklahoma Panhandles will advect warm, moist air up into Kansas and Nebraska. Warm air advection aloft and weak frontogenesis between the two airmasses will create lift over southern and southwest Iowa Monday into Tuesday morning. Soundings and cross sections show roughly -15 to -20 microbars of vertical ascent through the dendritic growth zone, with a healthy amount of mid- to upper-level saturation overhead. However, those same atmospheric profiles also show a stout dry layer in the low- to mid- levels, as the high pressure overhead advects drier air into the state. Therefore, while hydrometeors will be produced aloft, expectation is that any precipitation reaching the surface will be light. This is especially true Monday morning, where soundings would suggest mostly sprinkles/flurries, if anything occurs at all. Monday evening into Tuesday morning could have slightly better low to mid-level saturation to produce a brief period of snow overnight, but even then, dry air remains a concern over Iowa and will be reliant on the lift to saturate down through this dry sub-cloud layer. As we get into Tuesday, return flow on the backside of the high will begin to advect warmer, moist air up into the state. Depending on the model, better deep layer saturation will be achieved by late Tuesday afternoon/evening with broad scale lift being provided by the increased theta-e advection. Actual moisture content still won`t be overly high, keeping QPF rather low, but the better saturation certainly indicates an increased potential for precipitation later in the day Tuesday. With cooler temperatures initially, this may begin as snow, before transitioning to rain as the warmer air works northward. Of course, temperatures will play a big factor in precipitation type on Tuesday, so we`ll want to monitor temperature trends through the week as this warmer plume moves into the area. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Issued at 248 PM CDT Sat Apr 4 2026 With the state open to the gulf moisture stream, increased moisture transport will allow for more precipitation chances through the second half of the work week and generally into next weekend. A 500 mb trough passing over the northern CONUS will provide the synoptic support for rain along a trailing cold front through the day Wednesday and into Thursday. The upper level pattern transitions to a southwest flow regime through the second half of the week and into the weekend, as a trough digs in off the western CONUS. While the signal for any individual system is fairly muddy at this lead time, the overall deterministic and ensemble model consensus points toward a wet pattern starting around Wednesday and lasting through the end of the current 7 day forecast. In fact, NBM has over 50% PoPs starting 18z Thursday and lasting through 00z Saturday, indicating the overall model agreement for an active weather period. It`s unlikely it rains non-stop through this entire period, but given the healthy moisture stream, would not be surprising to see off and on rain chances occurring over most of this period. Thunderstorms are also possible through this period, but no strong signal exists for severe thunderstorms at this time. Will assess this threat in the coming days. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 631 PM CDT Sat Apr 4 2026 VFR conditions to begin the period with the stratus beginning to clear over far northwest Iowa. A period of MVFR though is still expected at KMCW/KALO this evening before returning back to VFR for the remainder of the period. Breezy to gusty west/northwest wind will settle slowly overnight however expect breezy conditions to prevail much of the period. && .HYDROLOGY... Issued at 248 PM CDT Sat Apr 4 2026 Widespread rainfall over the last couple of days has resulted in responses across multiple area rivers. Most of these rivers are forecast to reach and crest within action stage, especially over southwest into south central Iowa. However, rivers farther north and east in the area are seeing a few sites forecast to near or exceed minor flood stage within the next couple of days. These include sites along the Cedar River, Iowa River, and Skunk River. The site of most immediate concern is the Cedar River near Cedar Falls, where minor flood stage is forecast to be reached Sunday evening and a flood watch is now in effect. Sites along the Skunk River near Ames are cresting now just below minor flood stage, and aren`t expected to exceed flood stage at this time. The Iowa River near Tama is expected to reach action stage Sunday morning and crest in minor flood stage on Wednesday morning. Dry conditions over the next few days should give rivers some time to route water out of the system, but likely won`t fully recover to previous levels prior to additional rainfall later this week. Therefore, rainfall amounts and placement will be important to watch as we head into the second half of next week. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Dodson LONG TERM...Dodson AVIATION...Donavon HYDROLOGY...Dodson