Area Forecast Discussion
Issued by NWS Des Moines, IA
Issued by NWS Des Moines, IA
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069 FXUS63 KDMX 112325 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 625 PM CDT Sat May 11 2024 ...Updated for the 00z Aviation Discussion... .KEY MESSAGES... - Picture-perfect Spring Day today. - Shower and thunderstorm chances return to the forecast late Sunday afternoon and through Monday. - Additional thunderstorms by late week. && .DISCUSSION... Issued at 235 PM CDT Sat May 11 2024 If you`re looking for a glorious spring Saturday, this is it. Clear skies, temperatures in the mid to upper 70s, and a nice breeze. This nice stretch Friday and today is owed to a departing trough to the east and and incoming cut-off low to the southwest. Caught in between, Iowa has enjoyed a rare quiet stretch in what has been an active few weeks. And while Sunday will begin nicely, this comes to an end. By Sunday afternoon the cut-off low lifts out of the southwest and into the midwest. Showers and thunderstorms will develop across the area in the afternoon, continuing through the overnight and on Monday. Flow is fairly weak, in fact in soundings you have to look above 400 mb to find wind over 20kts. Decent CAPE of 1000-1500 J/kg will be present, but with that weak flow in place storms will struggle to organize so the severe threat is quite low. With such weak flow, storm motions will be exceedingly slow which could lead to pockets of heavier rain. At the same time, the system is battling dry air, especially across northern Iowa, which will likely mitigate some of the heavy rain potential. The low will pass to the south on Monday with showers and thunderstorms mainly central and south, ending by Tuesday in the southeast. Quickly on it`s heels comes the next system, a trough dropping across the Rockies and into the midwest on Wednesday into Thursday. despite some model differences at this time range, for now showers and storms associated with the passage look to remain sub- severe with the main instability axis pushed south of the area. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 625 PM CDT Sat May 11 2024 VFR conditions expected this period. Some increase in mid to high level clouds aft 18z Sunday; especially FOD/DSM as next storm approaches. Winds remain under 10kt through 14z most locations with some mixing aft 14z; occasional gusts to 15 to 19kt. Sct showers/iso thunder coverage aft 21z, if any, will be too sparse to include mention this period. /rev && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Hagenhoff AVIATION...REV