Area Forecast Discussion
Issued by NWS Des Moines, IA
Issued by NWS Des Moines, IA
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907 FXUS63 KDMX 152003 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 203 PM CST Sat Nov 15 2025 .KEY MESSAGES... - Warm and breezy today, then cooler and calm on Sunday - Precipitation chances returning late Monday, especially north and east. Mostly rain initially, with some drizzle potential overnight into Tuesday. - Mild temperatures continue, with more precipitation chances second half of next week. && .DISCUSSION... Issued at 156 PM CST Sat Nov 15 2025 << WARM & BREEZY TODAY, COOLER & CALM SUNDAY >> The surface cold front has made most of it`s way through the state today, with the secondary trough just now entering northern Iowa. This will continue to drop southward as the surface low over the Great Lakes region keeps on eastward and surface high currently over Montana and the Dakotas begins to fill in over the state tonight. With the tighter pressure gradients and cold air advection in place overhead, breezy winds are expected to persist this afternoon and evening. Gusts of 20 to 25 mph are expected, with a few areas in northeastern Iowa gusting near 30 mph this afternoon. Gusts will diminish tonight as the surface decouples and the pressure gradient lessens, but sustained winds will remain around 5 to 10 mph through roughly midnight. However, as the high pressure continues to push in overhead, winds will fall to around and below 5 mph into the morning hours, especially west. Calmer winds in conjunction with the drier dewpoints, could allow for efficient radiational cooling overnight, but will be dependent on skies remaining clear as well. A deck of low level clouds will move in with the high, mainly impacting western Iowa, likely keeping low temperatures from plummeting beneath. It will be areas on the eastern fringe of this cloud deck, where winds are still light but skies are clear, that could see temperatures drop rapidly on Sunday morning. High pressure then dictates the weather on Sunday, with partly cloudy skies, light winds, and mild temperatures in the 40s and 50s. << MONDAY NIGHT RAIN, DRIZZLE POTENTIAL >> The high pressure and quiet conditions on Sunday will be short- lived, as 500 mb ridging develops ahead of an approaching shortwave on Monday. As mentioned in prior discussions, this lobe of energy will originate from the closed 500 mb low currently off the coast of California, which is producing wet, soggy conditions for our friends from eastern Iowa currently visiting Los Angeles Memorial Stadium. As this system makes it`s way onto the main land, it splits into two shortwaves, one of which tracks northward through the Rockies and the other more east northeastward across the Rockies, through the Plains and eventually into Iowa. This system will bring the return of precipitation chances to the area, mostly in the form of rain for our forecast area. With the system trending more dynamic and slightly farther north, warmer air is being pulled up into the state, keeping temperatures warm enough to negate snowfall, aside from far northern Iowa. However, even in northern and northeastern Iowa where low level temperatures are cooler, both deterministic and ensemble soundings show a persistent warm nose around 2 to 4 C that will work to melt any snowflakes that fall through it. There could be an occasional wintry mix as the profiles saturate and cool, as melted snow refreezes below the warm layer, but even then current soundings would still favor a cold rain over frozen precipitation. Rain chances look to be most likely along the initial wing of increasing theta-e and as the low level moisture phases with the upper level moisture. This will be occurring late Monday into early Tuesday. However, while the phasing of the two moisture streams seems fairly limited in time and space on Monday night, there also looks to be a strong push of low level moisture with a 1 to 2 km saturated layer showing up at times in model soundings. Although lift isnt great through this saturated layer, this would imply the potential for occasional drizzle throughout central Iowa overnight Monday into Tuesday morning. With the warmer trend, surface temperatures should remain above freezing in most areas, but a few degrees cooler in northern Iowa could lead to some freezing drizzle potential on Tuesday morning. << WORK WEEK FORECAST >> The forecast will be relatively active through the rest of next week, with a brief break from precipitation during the day Wednesday. However, a southern stream 500 mb trough builds in the western CONUS before lifting northward into the midwest, bringing another potential for precipitation late Wednesday through Thursday and Friday. Early indications suggest mostly rain with this system, as the colder air is wrapped up in a northern stream wave passing through Canada. However, this is still over 5 days out, so will want to watch how these southern and northern stream troughs interact and for any trend toward colder temperatures, especially wrapping around the backside of the southern stream wave. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1159 AM CST Sat Nov 15 2025 VFR through the entire period. Breezy northwest winds will persist through the rest of this afternoon with gusts between 20-30kts. Winds speeds are expected to weaken after sunset once the remnant mid-level wave departs to our southeast. Some moisture advection is expected to occur aloft later this evening which could aid in the development of some mid-level sct cigs tonight. A few sites could see sct cigs reach low-VFR early tomorrow morning however reduction in flight categories are not expected. Winds tomorrow morning will remain light near 5kts in the NNW. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Dodson AVIATION...Dunleavy