896 FXUS63 KGRB 301117 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 617 AM CDT Mon Mar 30 2020 Updated aviation portion for 12Z TAF issuance .SHORT TERM...Today...Tonight...and Tuesday Issued at 328 AM CDT Mon Mar 30 2020 A ridge of high pressure will build into the western Great Lakes region today, bringing a gradual decrease in clouds from west to east. It may take until late afternoon before the clearing reaches the lakeshore counties. Gusty north-northwest winds will persist across eastern WI through most of the day. High temperatures will range from around 40 degrees far northeast WI, to the lower 50s over parts of central WI. Developing northeast flow and CAA is expected to cause cloud cover to increase from east to west again tonight into Tuesday. A few models suggest the potential for light lake-enhanced precipitation near MTW late tonight, but will leave it out of the forecast for now, as over-water instability is weak (Lake-H8 delta-t's of 7-9 C). Lows tonight should range from around 20 far northwest to around 30 east. Highs on Tuesday should range from the upper 30s near the lakeshore to the 40s inland. .LONG TERM...Tuesday Night Through Sunday Issued at 328 AM CDT Mon Mar 30 2020 The ensemble means continue to point towards a relatively quiet pattern during the upcoming week, though are struggling with the details later in the week. The overall trend has been to slow the eastward progression of an upper low and associated cold front from the northern Rockies into the western Great Lakes in the Wednesday through Saturday time period. Will lean on the ensemble means for the later periods. Tuesday night through Wednesday night...Quiet conditions will continue on Tuesday night into Wednesday morning with a surface ridge axis bisecting the state. Still see signs of light northeast flow and ample low level moisture hanging around over the eastern half of Wisconsin that could lead to broken to overcast conditions. Deeper moisture will try to move into the area from the west on Wednesday afternoon into Wednesday night, but run into drier air in the process. As a result, removed precip chances on Wednesday and kept a low chance in the forecast for Wednesday night. But wouldn't be surprised if precip chances slow down further. Depending upon how thick the cloud cover is on Wednesday, afternoon highs could be cooler than advertised, particularly over eastern WI due to east flow off Lake Michigan. Rest of the forecast...The front finally starts to make some progress east during the Thursday night through Friday night time period. As a result, most of Thursday could end up dry. Further slowing of this system is possible, but guidance generally points towards Friday and Friday night being the highest chance of precip with the frontal passage. There may be a break in the precip chances for a short time behind the front, before another chance of precip arrives late in the weekend or early next week. && .AVIATION...for 12Z TAF Issuance Issued at 612 AM CDT Mon Mar 30 2020 MVFR conditions will persist across much of the area this morning, but clouds will gradually decrease from west to east during the day. Ceilings will also rise to VFR by late morning or early afternoon, due to the arrival of drier air and the heating of the day. As northeast flow develops tonight, the low clouds are expected to spread back to the west, though it is uncertain whether MVFR conditions will make it back into RHI/AUW/CWA overnight. && .HYDROLOGY... Issued at 328 AM CDT Mon Mar 30 2020 Runoff from recent heavy rain has caused some sites along the Wisconsin, Wolf, Peshtigo, Oconto and Embarrass Rivers to reach Flood Stage. A number of other locations have seen water levels go above bankfull. Water levels should continue to slowly rise early this week, and peak Tuesday or Tuesday night before starting to fall. Residents living near rivers or streams should closely monitor water levels and be prepared to seek higher ground if flooding becomes imminent. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....Kieckbusch LONG TERM......MPC AVIATION.......Kieckbusch HYDROLOGY......Kieckbusch