Area Forecast Discussion
Issued by NWS Des Moines, IA
Issued by NWS Des Moines, IA
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642 FXUS63 KDMX 270440 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 1140 PM CDT Thu Sep 26 2024 ...Updated for the 06z Aviation Discussion... .KEY MESSAGES... - Extended period of tranquil and dry weather with above normal temperatures into Monday. - Cooler temperatures arrive by Tuesday but dry conditions persist. && .DISCUSSION... Issued at 331 PM CDT Thu Sep 26 2024 Quiet weather persists across the state this afternoon with ridge axis across the southeast. Otherwise, the dry atmosphere warmed nicely with plenty of sunshine this afternoon. Anticipate the tranquil conditions to persist tonight as the surface ridge begins to actually retrograde as the eastern upper low and Hurricane Helene interact. Patchy fog may once again develop toward daybreak given the light winds and ample radiational cooling although dont anticipate this becoming problematic. The overall pattern is dominated by the large upper low absorbing Helene and holding nearly stationary in the lower Ohio River Valley thorugh the weekend. Iowa remains on the backside of this large circulation with northeast winds but generally clear skies. Some clouds may back into the east third or so of the state during the weekend, but otherwise relatively sunny conditions are expected during the day. Temperatures continue with decent diurnal ranges with a relatively dry airmass in place and limited clouds. A stronger shortwave drops southeast into the Upper Midwest by Monday of next week. The bulk of forcing and associated lift remain well north of Iowa with relatively little moisture in the state. Therefore, the chances of precipitation with this system remains north of the state. However, a decent push of colder air is expected by Tuesday with temperatures dropping to or below normal, if only for a day or two. Warmer air returns quickly into midweek once again ahead of another fast moving shortwave which arrives by late in the work week. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1128 PM CDT Thu Sep 26 2024 VFR conditions ongoing and expected to continue through the TAF period. Isolated patchy fog may still develop around daybreak, especially towards river valleys, but not anticipating any widespread impacts and kept any mentions out of TAFs with <20% confidence of any restrictions/impacts at any one TAF site. Winds remain light and variable overnight but will increase and become out of the northeast during the daytime Friday, the strongest winds/gusts in the southeast towards KOTM where winds be be around 10-15 knots with gusts to 20 knots. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Cogil AVIATION...KCM