the climatological long term peak for the season is in about a week. we have had one system form already this month, and it should become a hurricane as the nhc surmises. maria may not have a whole lot of company, given the current pattern... aside from what could be a potentially weak storm or two.
maria is moving nw on the general forecast track which should take it up east of bermuda. still a variety of solutions via the global scenarios.. which show anything from a stall to interaction with low pressure to the west, to dissipation. the appearance of maria isn't one that favors dissipation... i wouldn't be surprised if maria becomes a solid hurricane before something finally catches the storm and shunts it out into the north atlantic... in a few days. a cat 2-3 range storm is within reason.
old 92L is no longer being tracked.. a trade wind surge overran it and flattened the low pressure area out, pushed all of the convection out to the surge line ahead of the system. it's very weak and mostly devoid of convective activity... and the low level convergence forcing from earlier has broken down. nothing to get it going again.. wave energy should propagate westward as long as nothing exists to get it active again.. unless the weakness left from that upper low maria developed next to is still nearby to create some differential and evacuation mechanism for convection.
the large surface trough swinging from east of florida to north of puerto rico up to near bermuda... has three focal areas. the center one north of puerto rico seems to be developing, as sustained convection and low cloud movements suggest a tropical low may be forming there. if it develops, it will move slowly and eventually to the northeast. closer to bermuda the area is ragged with an elongated surface turning... many globals track maria into this general area and show the storm merging into it... perhaps absorbing it. the westernmost of the focal points is north of the bahamas, and presents the biggest forecast problem. most models show a low pressure or some surface entity in this area.. sure enough most current surface plots show a weak open-type low near the persistent convective burst in this area. some of the more reliable global models that don't meld the entire region into a broad low show this feature bobbing around off the east coast and deepening slightly as shortwaves pass by to the north.. euro and nogaps have it swoop by the southeast coast around the middle of next week. none show a particularly tropical depiction, but based on climatology and a less-than typical baroclinic appearance, it could well be a tropical or subtropical feature.. albeit likely a weak one.
there is less support today, although some globals still show a weak wave of low pressure moving west across the gulf.
occluding low near the azores shouldn't have enough time to acquire subtropical characteristics.
the synoptic pattern right now is one that doesn't favor traditional longtrack-type storm paths. the african wave train appears to have subsided some, mjo has become essentially a non-factor (perhaps a very weak inhibitor), and soi is still oscillating.. indicating the tendency for weak, gappy ridging and frequent troughs with NAO responding by staying near neutral, and not providing clear pathways for storms to take. there isn't much to move the big weakness off the east coast and that should keep any atlantic systems for the next week or so offshore... globals not suggesting much action in the deep tropics. maybe something will struggle though.
what we're waiting for now.. and what should reactivate the tropical activity, is the polar low diving to its early fall position near northern canada.. instead of being centered near the pole with sluggish, unpronounced longwave features to the south. when that happens, it should result in a more conventional synoptic pattern. i suspect it will happen around mid-month.
HF 1501z03september