The Grinch Storm of 2024 One popular question I have fielded lately is, “Will this be as bad as the storm last December?” The answer to that is a challenge. Every significant storm is unique in itself. There will be those after the fact who will say it wasn’t that bad, and others will tell me that they got smoked. That is the nature of the beast with these things. On paper, it does not appear to be as bad as the December 18, 2023 version, which surprised some people who weren’t paying attention. This time, the shorelines are spared of another disaster as the main event occurs as the tide goes out. The snow that has recently fallen or has been manually made will help cut down on the flood threat somewhat, but there will still be issues. Power outages ranged to 400,000 in the storm last year, and I think it is a safe bet that at least 250,000 will lose power with this one, and some of those will be long-term, with a week to 10 days before restoration. This storm appears a bit more progressive, which helps to reduce the bleeding of the snowmelt and brings a shorter high wind window. The bottom line is the storm will be bad enough, and preparations need to happen. But first, pockets of ice for Tuesday Tuesday 7 AM (12z) to Wednesday 7 AM (12z) – Warm air advection aloft and cold air damming at the surface create pockets of light freezing rain and drizzle that will pop and fade at times throughout the day and into the evening. It would be wise not to move any of the snow that has fallen from the night before until later in the day if you can, or not at all. A surge of moisture works in from the southwest, heading toward sunrise Wednesday morning. Interior areas where cold air damming loves to hold on can expect ice to build up to where it may become concerning (¼-½”) and will cause slick driving conditions. Timing and precipitation type for Wednesday into Thursday Wednesday 7 AM (12z) to Thursday 10 AM (15z) – I keep talking about cold air damming over the interior, and I will continue to beat on that drum. I expect it to be stubborn in protected areas through the morning and before being washed out (literally and figuratively) in the afternoon. As I have discussed previously, this is July-type moisture in December with the atmospheric river from the south. Within this comes the threat of embedded thunderstorms that could drop copious amounts of rainfall, cause ponding on roadways, and potential for hydroplaning on the highways. There will be fog around with the snow. The wind will increase during the day and peak ahead of the cold front that passes through Wednesday night. Cold air crashes in on the backside Thursday morning. Any puddles over the interior will freeze up, and some places could turn into a skating rink as the day progresses. The flooding concern Tuesday 7 PM (00z Wednesday) to Thursday 1 PM (18z) – The European model idea of snow depth from its concept of snow coverage across the state (local results will vary). The idea presented here is a complete wipeout of the snowpack over the coastal plain on northward into the eastern parts of The County. The mountains absorb more rainfall, given the density of the snowpack, but also take a substantial hit. Within this snowpack resides anywhere from 1-4” of water content, and a substantial portion of that will be released. This is on top of the rain on the way, which will add insult to injury in how the 2023 Grinch Storm played out.  As a reference point, the storm last December brought the region a general 3-5” of rainfall, with upwards of 7” in the mountains, so the idea is not as bad, but it is increasing as the event closes in. The higher elevations will be the jackpot area, with the southerly wind throwing moisture against the terrain. With areas away from the western mountains, seeing the snowpack dissolve does bring concern for minor to moderate flooding downstream. The headwaters will also have their issues, with the potential for ice jams and flash flooding from rapid runoff. A few roads, trails, and driveways are likely to be washed out. Power outages on the way The good news is that the window of high wind gusts runs between 4 PM and around 11 PM for the west and south and from around 7 PM to 2 AM Thursday for the north and east. That said, the low-level jet will be screaming at above hurricane force, and what mixes down could bring a vertical threat and a horizontal one. Wind damage is inevitable given the dynamics as the storm intensifies into northeastern Quebec and bottoms out to around 975mb by midday Thursday. While the strongest gusts subside, the windmill continues through Friday and settles down as a cold Canadian surface high works in for Saturday and stays through Sunday. And about that cold air moving in... Wednesday 7 PM (00z Thursday) to Sunday 7 PM (00z Monday) – Forecast idea in degrees Celsius here for contrast and to make a point of the cold air mass moving into the region in the wake of the storm. Temperatures will struggle to get above freezing along the coastal plain and are expected to stay below freezing or flirt with the freezing mark for high temperatures through the weekend. This is for those who experience power loss and have no backup source for heat; this is very concerning for personal well-being and the potential for freezing pipes. The outlook is that the region will be storm-free until the middle part of next week. Make it routine to check the PTW Weather Wall for updates Appreciation for financial help to keep the coffee pot going, help me pay the bills, and train future forecasters Always have MULTIPLE ways to receive weather alerts. Stay aware, stay on alert, and stay safe. - Mike PRINT MEDIA: Feel free to quote and cite my work here for your stories. Please give me the professional courtesy of knowing that you are referencing my material so I can read your final product and acknowledge it on my media and link it on the PTW IN MEDIA page here on the website. Feel free to send me a message via the Facebook page or Twitter (X) to get my phone number if necessary. Thank you! NOTE: The forecast information depicted on this platform is for general information purposes only for the public and is not designed or intended for commercial use. For those seeking pinpoint weather information for business operations, you should use a private sector source. For information about where to find commercial forecasters to assist your business, please message me and I will be happy to help you. |
Mike Haggett
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