PHILADELPHIA (CBS) — This weekend’s weather will be dominated by the approach and eventual landfall of Henri. This is a very complicated and changeable forecast at this hour and there are wide discrepancies within our suite of forecast models.
As of Friday night, there are two potential scenarios for our region over the weekend and the ultimate solution will depend on the final track and timing of Henri and its interaction with an upper low that is currently located over the interior mid-Atlantic region.READ MORE: Philadelphia Animal Shelters, At Or Near Capacity, Hope Betty White Challenge Leads To Forever Homes
First and foremost, the threat for strong damaging hurricane or tropical storm force winds will stay offshore from our area. The center of the low will pass well off the New Jersey coast and the strongest winds will remain on the eastern side of the storm. There may be some minor coastal flooding with the approach of Henri, but largely the threat for any storm surge looks to be limited to Long Island and southern New England.
Our greatest concern, and the biggest wild card, will be the potential for heavy flooding rain. The global models (which traditionally handle the interactions of tropical systems and mid-latitude synoptic features a bit better) keep the heaviest rainfall more tightly packed around the center of Henri’s circulation, meaning the potential for heavy rain would likely miss us to the northeast.
The current official NHC forecast reflects this, with over 6 inches of rain forecast for southern New England and parts of New York state, but no mention of heavy rainfall for our region.READ MORE: MLK DAY: Events, Days Of Service In Honor Of Martin Luther King Jr.
However, several of our higher-resolution shorter range models Friday have begun hinting at the possibility for a plume of tropical rainfall to wrap around the western side of Henri at and after landfall, setting up the potential for downpours across interior sections of our area on Sunday.
If this were to occur, we’d be very concerned about the potential for flash flooding, especially given the still-saturated ground in the wake of Wednesday’s heavy rain event.
Saturday, on the other hand, doesn’t look like a washout in the city and interior sections of our region but does look like heavy downpours will be likely in the afternoon down the shore and along the coast of Delaware as tropical moisture from north-moving Henri interacts with the upper low.
The takeaway: the most drastic impacts of Henri will stay offshore from our region and impact areas to our north and east, but I am concerned about potential wraparound rainfall on Sunday.MORE NEWS: Wind Advisory In Effect In Philadelphia Region Monday After Snow, Rain Moved Through Delaware Valley
We will continue to monitor this potential throughout the weekend so please stay tuned for updates.