Area Forecast Discussion
Issued by NWS Des Moines, IA
Issued by NWS Des Moines, IA
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761 FXUS63 KDMX 081722 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 1122 AM CST Mon Dec 8 2025 ...Updated for the 18z Aviation Discussion... .KEY MESSAGES... - Warming trend to start the week, reaching the upper 30s to low 40s by Tuesday. - Strong cold front on Tuesday night will bring gusty winds 35-45+ mph overnight into Wednesday morning. Wintry mix is also possible with frontal passage. - Active pattern continues through the rest of the week with additional snow chances and colder air returning. && .DISCUSSION... Issued at 239 AM CST Mon Dec 8 2025 A weak PV anomaly, noted in GOES-East water vapor imagery, has resulted in patchy light snow across mainly northern into central Iowa overnight. Radar depiction is more robust than and snow that is reaching the ground in actuality with dry air in place. As this continues east through the early morning hours expect coverage to continue to decrease. Expectation for a dusting of snow at most for locations across northern Iowa. There is a signal in model soundings that ice introduction will be lost as the column de- saturates through the morning which could result in a brief period of light freezing drizzle. This has not materialized yet this morning and expect that with dry air in place any further de-saturation would result in precipitation stopping altogether rather than precipitation type swapping from snow to freezing drizzle. Even so with low likelihood, will keep an eye on conditions through the morning hours as freezing drizzle can be hazardous, especially for the morning commute. A shortwave will pass north of the area later today and into Tuesday, and while moisture will stay north of the area, warm air advection into the area will send temperatures through the upper 30s to low 40s on Tuesday. Despite the strong warm air advection into the area on Tuesday, the snow pack is likely to impact temperatures on Tuesday, especially across northern to central Iowa where the pack is deepest. Dewpoints are in the low to mid 30s in northern to central Iowa which may create a ceiling for the warming potential. A second, robust shortwave will pass across the area later Tuesday into Wednesday. This one will bring chances for rain, transitioning to a wintry mix, to northern and eastern Iowa. More notably, there will be strong cold air advection and subsidence behind the system overnight into Wednesday morning. This will result in windy conditions. Model soundings show 40-55+ kts through the mixed layer and expect we will need at least an advisory for these winds. Winds were nudged up on this shift, but expect further increases will be needed. Lastly, soundings continue to show some instability with the gusty winds overnight into Wednesday morning, which could result in more convective driven snow showers (HCRs/snow squall potential). Temperatures are colder Wednesday into the end of the week behind the system. The pattern remains active with additional snow chances Thursday and reinforcing cold into the weekend. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1122 AM CST Mon Dec 8 2025 For northern Iowa (FOD, MCW, ALO), widespread stratus clouds with MVFR and spotty high end IFR ceilings are prevailing at midday and should through much of the period. In addition, an area of fog is forecast to move eastward this afternoon into tonight with IFR visibility restrictions likely and cannot rule out a short period of LIFR. Farther south at DSM, VFR conditions are forecast to return late this afternoon with mainly VFR prevailing at OTM. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Hagenhoff AVIATION...Ansorge