Area Forecast Discussion

KEY MESSAGES

- Light snow showers this morning in the far north with minimal impacts and accumulations expected.

- Frost/Freeze warnings in effect for tonight.

- Warming trend this week with the next window for precipitation Thursday.

SHORT TERM /THROUGH TONIGHT/

Issued at 323 AM CDT Sun Apr 19 2026

GOES Nighttime Microphysics highlighted the incoming pocket of lower clouds associated with a shortwave. MPX radar had returns over southern MN, but with dew point depressions around 10 degrees. Better saturation is more into MN and will arrive in northern Iowa closer to sunrise, producing some snow showers to start the day. The lack of winds and QPF will keep impacts at a minimum. Westerly flow aloft will give some boost to temperatures in the southwest today (highs in the 60s) but the rest of the area will have highs similar to Saturday. The wind field is much lighter today. Gusts will top out around 20mph for most of the area.

Ridging covers the state tonight, translating to a surface high at the surface. Winds will be light. Some midlevel clouds may sneak into northern Iowa, but skies will otherwise be clear. Radiative cooling is likely, dropping temperatures below freezing for much of the state. The southwest may be spared since warmer southwest flow will commence once the ridge passes. Have issued a Freeze Warning where vegetation is sensitive and temperatures will fall into the 20s. A Frost Advisory covers the southern and western fringes of freezing temperatures. Frost will be possible because RHs will be higher compared to the prior two nights. If you're within or north of the frost/freeze headlines, be sure to protect sensitive plants.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 227 PM CDT Sat Apr 18 2026

500 mb ridging over the western half of the CONUS will generally control the weather pattern through the beginning of next week, putting the state in a northwest flow regime through Monday and Tuesday before the ridge passes overhead on Wednesday. Return flow on the backside of Sunday's high will advect warmer temperatures up into the area Monday through Wednesday, resulting in unseasonably warm conditions through the first part of the week. Persistent access to gulf moisture will be lacking through this period, although we do get a few periods of some better moisture transport which may allow for light precipitation chances by mid-week. However, for most of the area, this period looks warm, dry and breezy.

Later in the week, the ridging will be pushed off to the east in lieu of a broad 500 mb trough. This will bring a healthier push of gulf moisture, as well as synoptic support for more thunderstorms Thursday into Friday. The synoptic setup would certainly suggest severe weather will be possible, as is supported by NSSL and CSU machine learning probabilities for severe weather. However, it's a bit early to be putting stock in the environmental conditions. Most importantly, active weather looks to return Thursday into Friday of next week.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 639 AM CDT Sun Apr 19 2026

Little change from the previous issuance. Maintained prob30 for KMCW for the first hour, but most of the snow and MVFR cigs look to remain north of the site. Northwest winds may bring gusts up to 20kts today. Winds will then become variable overnight, gradually transitioning to a southeasterly wind by the end of the TAF period. Winds will be at 5kts or less while they shift.

DMX WATCHES / WARNINGS / ADVISORIES

Freeze Warning from midnight tonight to 9 AM CDT Monday for IAZ035>039-047>050-061-062-075-086. Frost Advisory from midnight tonight to 9 AM CDT Monday for IAZ060-073-074-084-085-095>097.