The threat for a direct hit from Hurricane Joaquin on the Eastern Seaboard has decreased. However, heavy rain, inland and coastal flooding, rough seas, beach erosion and rip currents continue to be a concern. However those with shipping interested in the Western Atlantic will be impacted.
As of 11 am ET, Joaquin remains a category 4 storm with winds speeds of 132 mph. Joaquin has move very little in the past 24-48 hours and is still near the Bahama Islands. The hurricane models this morning are showing a larger agreement toward a more eastward movement.
The current forecast from the National Hurricane Center is following the cluster with the more north to northeast directions away from the US coast and toward Bermuda.
We still caution however that this track remains highly reliant on Joaquin not getting caught by a broad upper level trough that has moved into the southern US. A couple of the hurricane models show that this upper low could still be a factor in the Joaquin’s motion, so the next 24 to 48 hours is critical.Thus until we see Joaquin move out of the Bahama’s and follow the northeast track, East coast residents are encourage to check for future updates and possible changes.
A component of the forecast that we do have a higher degree of confidence is excessive rainfall in the Carolina’s. Rainfall totals for the past 5 days have been impressive across much of the East Coast. Many locations have seen 1 – 2 inches with pockets of 3- 5+ especially in the North Carolina and Virginia mountains as well as Coastal Plain region.
The stationary front along the Southeast and Mid Atlantic will continue to be a focus for shower and thunderstorm development this weekend.
In addition, tropical moisture is streaming in from the south from Joaquin and interacting with the front. The observation from the morning balloon instrumentation launch from Moorhead City NC reported a precipitable water of 2.32 inches (shown below by the star in the left graphic.) Since this value is above the red line that indicates that it is near record levels for this time of year. In addition, when looking at the broader region (graphic below on the right) The shading oranges and pinks in the Carolina’s, Virginia, Maryland, Delaware and New Jersey show that this value is at least 150% of normal which is an indicator of the atmosphere being able to produce very heavy downpours.
Rainfall through Sunday will be widespread and significant, especially in the Carolina’s. Broad areas of 4”+ is expected in parts of North Carolina with totals of 8 to 10” in South Carolina.
Significant flooding is a concern with many areas. Flash Flood to coastal flood watches (showing in the green shading in the graphic below) are in effect for the next few days across much of Virginia and the Carolinas. Of increased concern is flash flooding in the hilly and mountainous areas. (Remember: do not drive into flooded roadways no matter what vehicle you are driving.)
In addition to the flash and areal flooding, the threat for river flooding is increasing with the widespread rainfall forecast. Many locations are forecast to rise to minor (orange locations) to moderate (red locations) levels in the next few days.
Some locations are already seeing flooding including Minor flooding on the Roanoke River at Randolph, VA while other areas, including Stevens Creek near Modoc, SC, are forecast to reach flood levels with the forecast rainfall over the next few days. In addition to the inland and river flooding, coastal flooding especially along the Virginia Coast and the Chesapeake Bay will remain a problem with each high tide. This will also cause beach erosion.
Those with interests along creeks, river and in lower areas along the coast are urged to remain aware for changing water levels and we recommend you take proactive measures now to decrease the damages to your property.
The team at WxIntegrations will continue to provide relevant information and resources to help you better understand and prepare by incorporating weather impacts into your planning and response.