Pay attention to the sky The cold front on track to pass through Maine on Friday has become a bit more amplified, which has caught the attention of the Storm Prediction Center. Isolated to scattered severe storms are possible in the afternoon as the day's heating maxes out and cold air moves in aloft.  The main concerns with storms are frequent lightning, damaging downdraft wind, and an isolated chance of ping-pong ball-size hail. Localized flash flooding from torrential rainfall may cause issues with hydroplaning on highways and urban street flooding. For those heading out for the day, it would be wise to close windows, secure the grill cover, and remove any loose items in the yard that could become airborne. Timing & potential Friday 6 AM to Saturday Midnight— The progression and trajectory of the frontal boundary has upped the ante on this scenario. Forecast guidance has battled internally over the timing of the passage, and even with the overnight runs of the short-term convection-allowing models, it still disagrees. That said, chances are good that some areas could get hammered. The bottom line here is that three factors will determine impacts. The first will be the dew point temperature. The higher into the 60s they go, the more gasoline around for developing storms can tap into. The “Slight Risk” region SPC highlighted over southwestern areas shows potential for 65-70° dew points. The second factor is cloud cover. As storms go through their lifespan, the clouds formed will blow around to the southeast, which may be enough to knock down severe threats closer to the coast. The third factor, always the wild card, is the sea breeze front. The sea breeze forms an inversion, which at times is referred to as a “cap.” This cuts off the heat rising aloft and thus neutralizes storms on approach or from forming. For southern coastal areas to get hit (Portland, Biddeford, Kittery), a west-southwest to westerly wind direction is optimal, to keep the ocean influence out of it. There is a fair chance that may happen here given the trajectory and sharpness of the front moving in. Frontal boundary progression key for Saturday Saturday Midnight to 6 PM – Expect areas that get hit with rain to see fog develop overnight. I mentioned in a post this week that the front may stall offshore, which is a distinct possibility. In that case, the HRRR suggestion here is showers remain a possibility over the coastal plain overnight and into Saturday morning. DownEast areas may end up dealing with shower activity through the morning and may not end until mid-afternoon. Prepare for brutal heat A rough idea of forecast temperatures for Fryeburg and Caribou beginning on Tuesday shows potential for record heat on the high and low end. Heat indices for the southwest interior could reach 105°, with swampy dew points in the upper 60s to low 70s. The region has not experienced this heat since 2022, as last summer was a washout. Expect uncomfortable sleeping conditions as overnight lows may not fall below 70°. The MidCoast and DownEast shoreline areas may get relief from the sea breeze from the cold ocean temperatures. The sea breeze front will be a feature to watch on Wednesday and Thursday as storms may fire along it. Expect poor air quality issues due to the high humidity and heat advisories to be issued.  You are reading this due to the generosity of those who have financially contributed to keep it going Always have MULTIPLE ways to receive weather alerts. Stay updated, 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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