955 FXUS63 KARX 101104 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 600 AM CDT Wed Oct 10 2018 .SHORT TERM...(Today and tonight) Issued at 300 AM CDT Wed Oct 10 2018 Early today a surface low was centered over northern IA with a cold front extending south from the low and a warm front extending eastward into central WI. A stronger upper shortwave trough ejecting out of the central plains will kick the surface low northeast towards the upper Great Lakes through tonight with the cold front sweeping across the area through the day today. Some showers/storms will continue ahead of the initial surface trough, with the highest chances east of the Mississippi. With MLCAPE only a few hundred J/kg, not expecting any severe storms today. One more mild day is in store with highs in the 60s over most of the area. Strong low-level cold advection will develop behind the front this afternoon into tonight with temps falling into the 30s tonight with west to northwest winds gusting 30 to 40 mph. A few showers will remain possible tonight mainly over northern WI on the backside of the surface low near the upper trough. .LONG TERM...(Thursday through Tuesday) Issued at 300 AM CDT Wed Oct 10 2018 Cool and overall drier weather will be the theme through early next week. High pressure will build in from the west on Thursday into Friday. However, low clouds trapped beneath an inversion will be slow to erode, and could persist into Thursday night. Thursday will be quite the change from the past few days with highs in the upper 30s to mid 40s and a tight gradient/cold advection behind the departing low keeping winds gusty from the northwest. Although we'll have to watch how the low clouds erode Thursday and some increasing mid/high clouds Thursday night, it still looks like much of the area will see a freeze Friday morning, with headlines likely to be needed. An upper trough translating across the region on Friday will bring some cloud cover with it, but the highest precip chances appear to be south of the area closer to a stronger shortwave trough. Highs will remain cool in the 40s, although with lighter winds. Models continue to point to shortwave ridging over the area giving way to broad upper troughing over the central US later in the weekend into early next week. Some brief return flow on Saturday behind the surface high will allow temps to rebound a bit, although only into the 40s to low 50s, cooling back into the 40s through Monday. Guidance differs on the placement of shortwaves within the broader trough, and consequently precip chances Sat night and Sunday. With 10.00Z runs of the global models continuing to be less aggressive with precip over the area given stronger shortwaves passing north and south of the area, confidence in any meaningful precip is low. High pressure then is expected for Monday before another shortwave drops southeast in northwest flow aloft for Tuesday. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) Issued at 600 AM CDT Tue Oct 9 2018 Storm system lifting northeast today, taking pcpn with it. Low clouds likely to hang through the better part of Thu. Cigs: ifr/mvfr look to hold across the TAF sites as the sfc low exits northeast but low level saturation hangs well to the west/southwest. Not anticipating much improvement until later Thu as high pressure starts to build in from the northern plains. WX/vsby: while most of the rain has moved east of the TAF sites, see some potential for a few more showers or drizzle, especially as the KRST/KLSE get behind the departing low. Not enough confidence to add right now, but something to watch. If drizzle, likely see a drop into MVFR vsby for a few hours. Winds: winds will swing west/northwest later this afternoon/evening and increase as pressure gradient tightens post the low/cold front. Strong and gusty - sustained around 20kts with higher gusts. Should continue for better part of the day Thu. && .HYDROLOGY... Issued at 300 AM CDT Wed Oct 10 2018 A cold front will push through the area today, ending the threat for heavier showers and storms. However, runoff of rainfall over the past several days will continue to result in elevated river levels and minor to moderate flooding on some rivers through the weekend with gradual rises on the Mississippi to near minor flood levels in spots over the next week. Have cancelled the Flood Watch for areas west of the Mississippi River into west-central WI where much of the rain has ended or soon will be ending, and extended the Flood Watch through 18Z over eastern counties in WI in collaboration with neighboring offices where an additional half inch or so of rain is possible. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...Flood Watch until 1 PM CDT this afternoon for WIZ017-029-034- 042>044-053>055-061. MN...None. IA...None. && $$ SHORT TERM...JM LONG TERM...JM AVIATION...Rieck HYDROLOGY...JM