Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 02/12/19

Area Forecast Discussion
National Weather Service Grand Rapids MI
1021 PM EST Mon Feb 11 2019 LATEST UPDATE... Update .SYNOPSIS... Issued at 310 PM EST Mon Feb 11 2019 - Snow and mixed precipitation moving into the southern zones late this evening then spreads north after midnight. - Mostly snow north of I-96 and up to a quarter inch of ice along I-94. - We expect a lull late Tuesday morning and afternoon then snow returns Tuesday evening with strong winds and blowing snow for Tuesday night and Wednesday morning. - Another storm could bring snow or a mix Thursday night into Friday morning. && .UPDATE... Issued at 1016 PM EST Mon Feb 11 2019 No major changes to the forecast with the update. I did add some more freezing rain to the southern parts of the CWA. Aircraft data and surface obs indicate the warm layer is already into parts of far southwest MI...warranting more freezing rain for the region. Will need to monitor the dry slot as it may limit the overall accumulations. The convective cluster down in OK is associated with a PV anomaly...which arrives here in the CWA around 21z Tue. && .DISCUSSION...(This evening through next Monday) Issued at 310 PM EST Mon Feb 11 2019 We replaced the advisory with a warning for the northern third of the the forecast area where heavier snow is expected and the potential for high impacts in falling and blowing snow occurs late tonight into Tuesday morning and again Tuesday night into Wednesday morning. We continue the advisory elsewhere with an earlier start time across the south. This is a two-stage event with the first batch tonight bringing the threat of icing across the southern forecast area and a quick 3 to 5 inches of snow further north. Most model soundings show mostly sleet during the heavy burst of warm advection precip late tonight across the south, but there could be a couple hours of freezing rain that would cause travel impacts and possibly enough icing to cause some power outages. The soundings do not appear to be as favorable for freezing rain as the recent event, but up to a quarter inch of ice is possible and, combined with strong east winds gusting over 30 mph, power outages are a concern. The dry slot moves through on Tuesday as the 850 mb low tracks across the central forecast area. Some freezing drizzle is possible across the north and central zones with drizzle across the south as sfc temperatures rise above freezing. Wrap-around snow moves in Tuesday evening with cold advection helping mix down strong wind gusts over 35 mph. Temperatures drop and blowing snow is expected to become widespread by Wednesday morning, similar to the conditions we saw last Friday morning. The lake effect snow will taper off by Wednesday night as sfc ridging builds in. The calm weather will be short-lived as a northern stream shortwave trough amplifies as it is moving in on Thursday and there is the potential for a quick hitting event Thursday night with snow or mixed precip. Still time to watch this as ensemble spread remains considerable. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 638 PM EST Mon Feb 11 2019 Impacts will continue to increase at the TAF sites tonight as a band of snow strengthens as it moves in from the southwest. In addition the wind will be on the increase with gusts over 25 knots likely to develop. As a warm layer tries to move in from the south late tonight into Tuesday it should switch the precipitation over to a mix which should include freezing rain/sleet. A lull in the intensity looks likely for the middle part of the day when the wind may drop off as well. Then by mid afternoon colder air starts wrapping in from the southwest along with another burst of mostly snow with expected impacts. && .HYDROLOGY... Issued at 310 PM EST Mon Feb 10 2019 Nearly all rivers in our area have now crested after responding to the volatile weather of the last 10 days. The one exception is on the Grand River, where a very broad crest continues to work its way downriver, and has passed through Grand Rapids in the last 24 hours. There continues to be a major ice jam causing ongoing flooding in the City of Portland. This jam has not changed significantly in the last 24 hours. Reports from Portland indicate water levels have dropped only slightly over the weekend. There is another ice jam that we are monitoring near Eastmanville, near the 68th Avenue bridge. This ice jam is currently fairly small, and is not currently resulting in additional flooding. There are no ice jams in the Grand Rapids area, but we are still monitoring that potential as the water will remain high for at least several more days. As we head into another week of rapidly-changing and high-impact weather, any additional rainfall or snowmelt will send more water into the rivers, and delay the already-slow drop we need on our larger rivers. So far it looks like much of the area will see mostly snow this week, which will not have an immediate impact on the rivers, but will set the stage for future snowmelt. && .CLIMATE... Issued at 310 PM EST Mon Feb 11 2019 Here are the record snow totals for February 12th... Muskegon...3.9 inches in 1969 Grand Rapids...4.2 inches in 1964 Lansing...5.0 inches in 1894 and 1897 && .GRR WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 1 PM EST Wednesday for MIZ058-059- 064>067-071>074. Winter Storm Warning until 1 PM EST Wednesday for MIZ037>040- 043>046. Winter Weather Advisory until 1 PM EST Wednesday for MIZ050>052- 056-057. && $$ UPDATE...MJS SYNOPSIS...Ostuno DISCUSSION...Ostuno AVIATION...MJS HYDROLOGY...Dixon CLIMATE...Ostuno