Friday, August 20th 2021, 8:58 pm - Grace will bring flooding rains and dangerous storm surge to Mexico as a hurricane, with Henri likely to become a hurricane by Saturday as it approaches the U.S. East Coast.
Two storms are set for impact into the weekend. The first, Grace, is poised to strike central Mexico Friday night, possibly as strong as a Category 2 hurricane. Another, Henri, is slowly gathering strength in the Atlantic ahead of an impact on the U.S. East Coast. Beyond, there's a chance of some effect on Atlantic Canada also. More on the ongoing storms, below.
GRACE STRENGTHENS INTO A HURRICANE, POISED FOR SECOND LANDFALL
After making landfall as a hurricane on Mexico's Yucatan Peninsula Thursday and weakening to a tropical storm soon after, Grace regained hurricane strength as it continues to move across the Bay of Campeche.
On Friday evening, the storm's maximum winds were 150 km/h, a high-end Category 1, and was still increasing, and may make landfall as a Category 2 Friday night, according to the National Hurricane Center.
On Friday evening, the storm was The storm is currently 246 km east-southeast of Tuxpan, Mexico, moving west near 17 km/h.
The hurricane’s strong winds will likely lead to structural damage, downed trees, and power outages for the affected areas.
Grace’s biggest impact in Mexico will be its heavy rainfall. The hardest-hit areas could see 150-300 mm of rain, with isolated amounts higher than 450 mm. This deluge could lead to widespread flash flooding and mudslides, especially in mountainous regions.
As well, the storm surge will be a threat, and it could raise water levels by 0.91-1.52 metres above normal tide levels within the hurricane warning area. Near the coast, the surge will be accompanied by large and destructive waves.
A Hurricane warning is in effect for the coast of mainland Mexico from Puerto Veracruz to Cabo Rojo while a tropical storm warning is in place for the coast of mainland Mexico from north of Cabo Rojo to Barra del Tordo.
Grace's remnants are expected to continue westward and emerge over the eastern Pacific Ocean off the west-central coast of Mexico early Sunday. Environmental conditions are forecast to be conducive for development, and a tropical depression is likely to form late weekend or by early next week. The NHC gives the system an 80 per cent chance of developing again off Mexico’s West Coast in the next five days.
HENRI ALMOST A HURRICANE IN THE WESTERN ATLANTIC
Hurricane, tropical storm and storm surge watches have already been issued for parts of the northeastern U.S. in advance of Henri's arrival. While it was still a tropical storm, NHC is expecting it to intensify into a hurricane by Saturday, and possibly make landfall while still at hurricane-strength.
The centre of the storm is 470 km south-southeast of Cape Hatteras, N.C. Henri is moving west-northwest near 11 km/h, and is forecast to accelerate toward the north through early next week and approach the coast of southern New England on Sunday.
Maximum sustained winds are near 110 km/h with higher gusts. Strengthening is forecast, and Henri is expected to become a hurricane by Saturday.
Henri may produce rainfall amounts of 50-125 mm over southern New England Sunday into Monday, with isolated maximum totals near 200 mm. Heavy rainfall may result in areas of flash, urban, and small stream flooding.
The forecast can get a bit complicated for its impacts beyond the weekend.
There’s still a fair amount of uncertainty in Henri’s track early next week. Winds circulating around the high will try to steer the storm on a north-northeasterly track, but a ridge of high pressure over Quebec will likely block the storm from following that steady path.
The delicate interaction between steering winds and the blocking high over Eastern Canada will determine where Henri tracks early next week. A slight nudge to the west could bring the storm into New England, while a jog to the east would likely take the storm out to sea.
(Canadian Hurricane Centre)
It’s still too soon to know what impacts the storm will have on Atlantic Canada, but Environment and Climate Change Canada did issue a tropical cyclone statement for Nova Scotia. We’ll likely know more by this weekend.
Thumbnail is a satellite image of Hurricane Grace, courtesy of NOAA.
Stay tuned to The Weather Network for the latest on the tropics.