Heavy Rain Threat – Wed Update

First, for phones and other devices which don’t support Java or Flash, the local animated gif radar loop from Accu Wx will be a good source as any:

Our heavy rain event is unfolding. Blocking high to our north, while an upper-air low drops south from the Great Lakes and stalls to our west, enabling a butt load of moisture to work into the region aloft. The abundant moisture, a stationary high to our north, stationary low to our west/southwest, and the resultant squeeze play between the two occurring on top of us…..this is the setup for potentially heavy flooding rainfall over the next 3 days.

Models vary. The Canadian Hi-Res regional is forecasting a bodacious (always wanted to use that word in an email!) 6 to 10″ for MD and nrn VA. The NAM pulls the heaviest rain farther west into the mountains, with the I-95 corridor getting 2 to 3″. The GFS is a widespread 2 to 5″ event for everyone from the mountains to the bay. The rest of the agree with heavy rain… but they’re all over the place with where exactly it falls. Note, even if we “miss” the heavy rain (which I’m sure the folks in Ellicott City would prefer), we’re still looking at 1-2″ between now and Saturday morning, and that’s the low end.

Next week… a tropical low organizing east of the Antilles is forecasted to move west into the Caribbean over the weekend and strengthen, then turn north next week and head up toward the East Coast. The blocking high to our north is not expected to give any ground, and this sets the stage for a potentially interesting — if not dangerous — situation. It’s more than 7 days away, and as you can see with this week’s rain, getting the details in a forecast of any kind are difficult… and if we’re talking a week or more away, that’s “Dreamcast”. Yet even with the potential East Coast hurricane a week away, the long-range forecast models all agree this storm will threaten the Atlantic Coast. The Canadian and GFS bring it ashore in the Carolinas then up into MD/DE/PA toward the end of next week. The European is much slower, and has the storm south of Florida at the end of next week. Just something to keep an eye on. As always, your best bet is to keep an eye on the NHC website:

Talk to everyone soon.


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