Melissa is in full on beast mode Melissa is an impressive storm. I am thinking and praying for the folks in Jamaica. The core of the storm is small, which is typical for southern Caribbean hurricanes. The inflow to the east makes it look larger. There is a lot of moisture to work with, along with very warm sea surface temperatures to feed into it. This is a horrific situation for Jamaica.  The National Hurricane Center predicts that Melissa will reach CAT5 status Sunday afternoon and crawl through Jamaica, blasting the island nation for upwards of 60 hours. This brings Hurricane Dorian to mind, which decimated a few islands in the Bahamas back in 2017. That storm was like a high-end tornado that just sat and spun for two days. At least this one is expected to keep moving, albeit slowly. Under the hood of the dynamics Maine won't deal with direct impacts from Melissa. The question at this point is if the region will pick up moisture from the storm in the form of what is meteorologically known as a predecessor rain event (PRE), which is a fancy term for entrainment. Outflow moisture from Melissa may interact with an approaching trough. With a trough plunging in to the west of the region, there are some ideas out there that it may tap into moisture from Melissa as it races northeast later in the week. With Melissa forecast to run towards Bermuda, the timing and intensity of the trough will be indicative of whether Maine will benefit from its moisture, or not.  Using the European AI Ensemble, as it does a good job of balancing out the ideas of several different model ensembles. In my opinion, the line of demarcation is clearly drawn between the output of the deeper trough and that of the weaker one. With guidance ideas trending more to the east with Melissa, if that materializes, it would favor less rainfall. I mentioned in Saturday's post that I have guarded optimism about rainfall given the dynamics here. This is why.  The focus on the European AI ensemble ideas for Rockland. A definer: the blue "control" line is essentially the output one would see on an operational chart. The green "mean" line represents a blend of all the ensemble ideas to produce an average. This chart shows many variables for rainfall between the start and end times, along with amounts. It's about a 50/50 split for rainfall ±1" between 8 PM Thursday and 8 PM Saturday (throwing out the three outliers that start earlier). I am thinking it is likely to be a damp, breezy Halloween. How much rainfall and wind is still to be ironed out. For those with decorations outside, it would be wise as part of your Sunday to secure what you have in place as a precaution, especially along the coast. Stay tuned. Time to get in your last rounds of the season The PTW Weather Wall updates 24/7  Your financial support keeps the lighthouse lit |
Mike Haggett
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