653 FXUS63 KGRB 091947 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 247 PM CDT Tue Oct 9 2018 Forecast discussion for routine afternoon forecast issuance .SHORT TERM...Tonight and Wednesday Issued at 247 PM CDT Tue Oct 9 2018 Potential for heavy rain over the next 24 hours remains the primary concern across northeast WI. A secondary concern is the potential for stronger storms late this afternoon/early evening over a small part of east-central WI that remains in the warm sector. Another thunderstorm chance to arrive Wednesday afternoon ahead of a cold front. The 19Z MSAS surface analysis showed an area of low pressure over east-central KS with a quasi-stationary front stretched northeast through east-central WI. To the south and east of this frontal boundary, Indian summer was located with temperatures in the 80s and dew points in the 60s. To the north and west of the front, temperatures were more early winter-like with 30s and 40s. The radar mosaic picked up on scattered thunderstorms in the warm sector from MO into WI and MI. Some of these storms had become strong to isolated severe. These strong to severe storms are expected to continue into this evening and could impact east-central WI for a short time as SBCAPES have surpassed 1K J/KG with 0-6km bulk shear at ----- knots. Otherwise, the quasi-stationary boundary may sag a bit south tonight, but remain a main player on precipitation trends/temperatures across northeast WI. Another feature to watch will be the northeast movement of an area of low pressure that is forecast to reach the Midwest by 12Z Wednesday. The combination of additional mid-level shortwave energy, abundant gulf moisture and a diffluent flow aloft will bring another round of moderate to locally heavy rain to the forecast area. Do not plan on making any changes to the Flood Watch as models continue to show higher rain amounts over central/northern WI. Min temperatures to range from the lower to middle 40s far north-central WI, to the lower 60s south. The surface low is progged to track toward central WI and deepen in the process as the main upper trough lifts northeast into the Upper Mississippi Valley on Wednesday. As all of this occurs, a cold front is forecast to sweep east, reaching central WI by 00Z Thursday. Anticipate yet another round of showers (with some thunderstorms) to take place ahead of the cold front. Locally heavy rainfall is again possible which would aggravate any localized flooding, as well as raise some river levels toward/ above flood stage. Max temperatures to range from the lower 50s over Vilas County, to around 70 degrees east-central WI (away from Lake MI). .LONG TERM...Wednesday Night Through Tuesday Issued at 247 PM CDT Tue Oct 9 2018 Rain showers will come to an end from west to east Wednesday night as a cold front tracks through the western Great Lakes region. However some wrap around showers will likely remain across north-central Wisconsin through Thursday morning with some snow flakes possibly mixing in late Wednesday night and early Thursday morning across the far north. Much cooler air will filter in behind the cold front, with the largest temperature swings expected across central and east-central Wisconsin where the warm front lifted far enough north for warm, moist air to be felt during the last few days. Very breezy westerly winds will occur behind the cold front late Wednesday night into Thursday, with wind gusts of 25 to 35 mph expected. High pressure will then build in across the western Great Lakes behind the departing low, which will keep the weather dry across most of the area through the early part of the weekend. The exception will be across far north-central Wisconsin where some lake effect showers may occur at times. Highs will fall to well below normal levels for this time of year starting on Thursday, and will last through early next week. These cold temperatures will bring the chance for frost and freezing temperatures across the Fox Valley and lakeshore Thursday night and Friday night where these headlines are still being issued. Several low pressure systems will then bring several chances for light showers to the area for the second half of the weekend and continuing through the early part of next week. However these systems will bring much less rain to the area than the current system, which should help to prevent any rivers from being further agitated by heavy rainfall. Given the cool air in place with these lows, some snowfall could accompany the showers at times, mainly during the overnight and early morning hours across north-central and central Wisconsin. Any snowfall accumulation that occurs would be fairly light. && .AVIATION...for 18Z TAF Issuance Issued at 1249 PM CDT Tue Oct 9 2018 A quasi-stationary front will continue to separate low clouds and fog from more summer-like cumulus field with no fog. For the RHI, AUW and CWA TAF sites, expect mainly IFR conditions to prevail over the next 24 hours with periods of rain showers. For the ATW, GRB and MTW TAF sites, VFR conditions are expected for the rest of this afternoon, before cigs/vsbys gradually drop into the IFR category by mid-evening. Scattered thunderstorms are expected this afternoon over eastern WI where instability is stronger. Thunderstorms are also possible on Wednesday over all of northeast WI as a cold front pushes into the region. A low-level jet will develop tonight at each TAF site, resulting in LLWS. && .GRB WATCHES/WARNINGS/ADVISORIES... Flood Watch through Wednesday evening for WIZ005-010>013-018>021- 030-031-035-036. && $$ SHORT TERM.....Kallas LONG TERM......Kurimski AVIATION.......Kallas