013 FXUS63 KILX 070808 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 308 AM CDT Sat Sep 7 2013 .DISCUSSION... ISSUED 308 AM CDT Sat Sep 7 2013 SHORT TERM...Today through Sunday Latest surface analysis showed a cold front stretching from northern MN down into central NE, with a couple weak low pressure waves along the boundary. High pressure over the mid-Atlantic coast was ridging back west into the mid-Mississippi River valley and keeping conditions quiet and mild locally. Main forecast issue this weekend will be coverage of convection associated with the boundary currently to our northwest, as it drops south into the region tonight and Sunday. A couple high-res models develop convection as far south as the northern CWA this afternoon but feel this is overdone given dry airmass and strong capping in place ahead of the boundary. Assuming this activity stays to our north through this afternoon, skies should be mostly sunny, and with warm advection bringing 850mb temps to around +20C highs should get up into the lower 90s west of I-57. As the front moves in from the north overnight, most models are developing a weak frontal wave in the MO/IA/IL tri-state region which could act to increase moisture convergence and lift along the boundary. Given recent trends and drought conditions in place will keep pops at slight to low chance. The front will slowly work south through the central and southern CWA on Sunday and with the potential for widely scattered thunderstorms will keep low and slight chance pops in place. Due to anticipated easterly winds north of the boundary and more cloud cover highs will be a few degrees cooler, in the mid to upper 80s. LONG TERM...Monday through Friday A mid-level trof currently over the Pacific northwest shifts into the northern Rockies on Monday, pushing a surface low and front into the Upper Midwest. Southwest flow ahead of this feature will send this weekend's front back northeast, and allow another round of late season heat to set up across the region. Widespread highs in the 90s and lows in the 70s look on track for Monday through Wednesday. As the upper wave shifts into the Great Lakes on Wednesday the front gradually works southeast scattered storms could work into the northern CWA in the afternoon. Appears best chance of storms will be Wednesday night as the front moves through, but with unfavorable diurnal timing and unimpressive convergence along the boundary, feel this system will do little to bring widespread beneficial rains. The upper pattern becomes fairly amplified by late week with a strong ride over the Rockies and a deep trof over the eastern U.S. and Canada. This puts the area in strong northwest flow aloft initially, and with a large Canadian high building towards the Great Lakes, temperatures should trend towards normal. This high will ensure dry weather persists into next weekend. 25 && .AVIATION... ISSUED 1125 PM CDT Fri Sep 6 2013 Still a concern for some shallow ground fog in the 10z-13z time frame but it still appears coverage will be too limited to include in the TAFs. In addition, some high level clouds will streak SE into the area during the early morning hours which may prevent any widespread fog formation. After 00z Sunday, a frontal boundary will approach the area from the north with widely scattered TSRA accompanying the boundary. Not very confident on coverage or timing as models differ on those solutions late tomorrow afternoon and evening. At this point, will bring VCTS to PIA around 00z but not include at other sites for now. Forecast soundings not showing much in the way of cumulus development tomorrow afternoon, so other than some scattered to broken cirrus, not a great deal of cloud cover in our area until tomorrow evening ahead of the weak cool front. Surface winds will be light southerly tonight and pick up in speed on Saturday from the SSW at 8 to 13 kts, with possibly a few gusts early in the afternoon at PIA. SSW winds will quickly diminish again towards sunset. Smith && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$