192 FXUS63 KDMX 050953 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 353 AM CST Sat Jan 5 2019 .DISCUSSION.../Today through Friday/ Issued at 352 AM CST Sat Jan 5 2019 The thermal ridge will move across Iowa today with the 925 mb temperatures nearly 3C warmer than Friday. Mid-level clouds will be passing across Iowa today and will filter the sun at times today. These clouds may have some impact on temperatures, especially over the northern portion of the state. Still have high temperatures warmer than Friday but the clouds will be a concern as temperatures do not respond well under cloud cover this time of year. The upper level ridge will arrive Saturday night followed by increasing southwesterly flow Sunday as the ridge shifts to the east. This will allow for mid to upper level theta-e advection originating from the Pacific to arrive early Sunday and will be joined by low level Gulf moisture later in the day. Expect a gradually descending mid-level cloud deck much of the day before the better deep layer saturation arrives. At this time it appears that much of Sunday will remain dry through 6 pm though a few sprinkles or showers may develop after 3 pm. Precipitation chances should increase quickly Sunday evening. Despite the deep layer saturation resulting in PWATs over 1 inch and over 350 percent of seasonal values, the system will be quite progressive and will limit the precipitation residence time. Still one quarter to one half inch of precipitation is likely by 6 am Monday morning. Much of the precipitation should be out of the area by that time leaving much of Monday dry. Temperatures Sunday will be slowed by the increasing clouds and high temperatures for the day likely will occur during the evening as temperatures continue to slowly rise. A boundary will enter western Iowa late Sunday night and will start to bring some cooling. Temperatures should be above freezing at all locations as precipitation occurs and therefore have kept the precipitation as all rain. Temperatures are a bit tricky on Monday as cold advection occurs during the morning and sky conditions will be clearing during that time. Warm advection arrives quickly by the afternoon along with a few more mid-level clouds. Currently have highs in the low 40s north to low 50s south though those temperatures may be a bit optimistic. Northwest flow aloft will develop by Tuesday allowing for a strong cold front (though not an Arctic boundary) to pass through the state. The combination of the cold advection, mixed layer winds in excess of 40 kts and a tight pressure gradient will bring the potential for wind gusts of 40 to 50 mph at the surface. With current timing, temperatures will be falling through the day and will be a drastic change from the recent very warm early January weather. The remainder of the forecast includes low precipitation chances with a roller coaster of temperatures. && .AVIATION.../For the 06Z TAFS through 06Z Saturday night/ Issued at 1137 PM CST Fri Jan 4 2019 Fog has developed at KALO and will likely persist at times through 13z. Elsewhere sct to bkn high level overcast beginning to spread southeast across the region. Remainder of sites expected to remain VFR at this time. Front will drop south into the region aft 18z and winds will becoming more northerly. HIRES models still suggesting post frontal 3-5sm or lower may develop briefly aft 00z mainly north sites KMCW,KALO but may need further adjustments next packages as confidence remains low from model run to run. /rev && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Donavon AVIATION...REV