- Henri a Threat to New England by Sunday: Weather models are notably slower and further west with Henri over the last two days. These shifts increase the risk for tropical storm impacts by Sunday for New England and possibly Atlantic Canada by Monday.
- Grace Makes Landfall on the Eastern Yucatan Peninsula: The forecast for Grace verified, making landfall just south of Tulum, Mexico early Thursday morning with maximum sustained winds of 80 mph. Grace will emerge into the Bay of Campeche later today and make a second landfall on the mainland coast of Mexico tomorrow as a category-1 hurricane.
- Remnants of Fred: Rainfall associated with the remnants of TS Fred are moving through New England today and Atlantic Canada tomorrow. Wind reports of isolated damage were reported through the Mid-Atlantic yesterday, along with rainfall totals of 3-6″.
Tropical Storm Henri Discussion
- Why the Shift Towards the US/Canada Coast? Over the last two days, Henri has verified on the southwestern edge of weather models as the tropical storm slowly tracks southwest of Bermuda. Recent verification decreases confidence in a track directly out to sea. Inclusion of more frequent weather balloon launches and commencement of hurricane hunter flight data into weather models will continue to provide clarity on the forecast of Henri. These data will help clarify whether Henri makes a close approach to the North America coastline with minimal impacts or ultimately makes landfall.
- Intensity Forecast – Short Term Strengthening, Longer Term Weakening: Sea surface temperatures are anomalously warm ahead of Henri, which will allow for strengthening into a category 1 or 2 hurricane by Saturday, including tracking over the Gulf Stream. However, the last 12-24 hours of Henri’s track before potential New England impact will track over notably cooler waters, with an expectation that Henri will decrease to tropical storm strength before a possible landfall.
- Probability of Tropical Storm Force Winds Onshore: On account of the westward shift, the National Hurricane Center is forecasting the probability of tropical storm force winds for the following coastal locations today.
What’s Next for Henri?
- More Data from Aircraft and Weather Balloons: Four hurricane hunter flights are scheduled today to fly into Henri as well as take measurements of the western Atlantic atmosphere around Henri. These data will increasingly help weather models narrow down the solution of possibilities for Henri.
- Short Term Strengthening and Impact on Longer Term Track: Analyzing the spread of outcomes in weather models, the tracks that are on the western side of guidance and making US landfall are generally solutions that are stronger with the strengthening of Henri in the next 24-48 hours. Models that show nominal strengthening of Henri ultimately track further east and out to sea. Thus, the strengthening of Henri on Thursday and into Friday is an important aspect of the ultimate track outcome of the storm.
- Impact of Fred in the Northeast US: The remnants of TS Fred are tracking through the Northeast US and into Atlantic Canada tomorrow. Heavy rainfall of 2-4″ is possible, adding to what has been a wetter than average last 60 days across the region. Elevated soil moisture has the potential to increase tree fall risk and ancillary damage due to the root system of trees being less stable with increased water in the soils.
North America satellite highlighting Hurricane Grace over the Yucatan Peninsula, Tropical Storm Henri east of Jacksonville, FL and the remnants of Tropical Storm Fred tracking through New England.. Source: NOAA/NESDIS.
Current National Hurricane Center forecast for Tropical Storm Henri. Source: NHC/NOAA.
Spread in weather model guidance for the four day forecast for Tropical Storm Henri. Forecasts further west are stronger with the intensification of Henri in the next 36 hours, while weaker tracks are on the eastern side of model guidance. Source: Tomer Burg, University of Oklahoma.
Weather model intensity guidance, with the red box highlighting the time frame of most likely interaction with the US/Canada coastline. Source: Tropical Tidbits.
Timing and likelihood of tropical storm force sustained winds with Tropical Storm Henri. Source: NHC.
Elevated rainfall totals over the last 60 days across parts of New England, with additional rainfall from the remnants of Tropical Storm Fred today, raise the risk of elevated treefall due to wet soils if Henri makes landfall. Source: NOAA/AHPS.
Guy Carpenter meteorologists continue to closely monitor the forecast of Tropical Storm Henri. The next update will be issued if Henri looks to make landfall as a strong tropical storm or if the forecast trends stronger for a category-1 landfall.