Area Forecast Discussion
Issued by NWS Des Moines, IA
Issued by NWS Des Moines, IA
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594 FXUS63 KDMX 281127 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 627 AM CDT Tue May 28 2024 ...Updated for the 12z Aviation Discussion... .KEY MESSAGES... - Scattered showers and perhaps a few thunderstorms today with very low severe risk. - Quiet through the middle of the week with showers and thunderstorms returning to the forecast Thursday into Friday and the upcoming weekend. && .DISCUSSION... Issued at 220 AM CDT Tue May 28 2024 Quiet across the area early this morning as Iowa sits between two shortwaves embedded within the parent trough a cross the upper midwest. This shows up nicely in GOES water vapor imagery as one shortwave drops out of the Dakotas (more on the next) and the other moving across southern Wisconsin. By later this morning that shortwave across the Dakotas will drop across Iowa, providing enough forcing for scattered showers across the area. Instability is weak, under 500 J/kg, so the severe threat is pretty low, but a few rumbles of thunder are possible. Soundings also remain pretty dry across the area which will limit more widespread shower development and reduce QPF. Expect under 0.1" with most showers into the afternoon. With drier low levels, gusty winds may develop with showers this afternoon due to evaporative cooling but that should be the extent of any impacts. This will be followed by a dry period Wednesday into the first part of Thursday as a narrow ridge passes across the area, squeezed between entering and exiting troughs. By Thursday afternoon an upper level trough moves towards the area with southerly flow pulling deep moisture transport back into the area. The system stalls out Thursday into Friday across western Iowa before pushing across the area Friday. The instability axis looks to remain south of the area based on current guidance, which would help to limit severe potential across the area with this system. Still plenty of time for this to shift in the coming days. Another wave looks to follow quickly behind, however model solutions diverge at this time frame with substantial differences between the most recent GFS and Euro runs. && .AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 627 AM CDT Tue May 28 2024 Showers across northwest Iowa early this morning will pass across northern and eastern Iowa through midday with impacts at KFOD/KMCW/KALO. Given the scattered nature of the shower activity, have kept as VCSH for now. There is less confidence in showers making south to KDSM/KOTM so showers we excluded from those sites. Otherwise, VFR conditions are forecast for most of the TAF period. Winds through the period will shift to straight out of the north after 00z this evening. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Hagenhoff AVIATION...Hagenhoff