While we emphasize that this is not Hurricane Harvey, nor is it likely to be Tropical Storm Allison, Nicholas is likely to drop a LOT of rain across a large swath of east Texas including the entire Houston area. Six to 10 inches of rain are expected in most places with bullseyes of 20-plus certainly possible. Here are some thoughts on this mess of a storm.
Forecasting this storm has been particularly difficult.
But, why? Partly the storm itself and partly the shape of the Texas coastline. Even Sunday night, the eye of the storm was found southwest of original projections. That could change as the storm continues to try and wrap clouds around the low pressure area. Where that center eventually forms — closer to Mexico or farther out to sea — will make a difference in landfall because the Texas coastline is a curve. Farther south and the storm probably comes ashore closer to the Texas-Mexico border. Farther north and east and you get landfall in the coastal bend region. That's several hundred miles. The National Hurricane Center still believes a landfall somewhere between Corpus Christi and the coastal bend is most likely and they are really good at what they do.
Hurricane Ida blew up, but Nicholas won't.
The rapid intensification of Hurricane Ida before landfall in Louisiana was unfortunate, but not surprising. It had time over water, was fairly well organized and moved across one of the deepest eddies of ocean water in the Gulf on its way to land. Nicholas has none of that going for it. Not only is it terribly disorganized, it won't spend more than about 36 hours over water. Plus, it is going to encounter some fairly significant wind shear before landfall inhibiting development.
Rain is the big problem here.
As we know from life along the Gulf coast, it doesn't take a massive hurricane to wreak havoc. As scary as high winds are, rainfall can be just as deadly and devastating. We don't even need the storm to be tropical in nature to do that. The folks at Space City Weather have elevated their Flood Alert to Stage 3 which is on par with the 2016 Memorial weekend floods and Tropical Storm Imelda. Both had substantial impacts on specific areas in our region. This storm seems destined for something similar.
We don't know exactly where, but we do know when.
First, the where. The entire coastline from Corpus Christi all the way into central Louisiana is going to see significant rainfall, but because of wind shear coming from the west, those on the left (west) side of the storm will see only marginal amounts compared to those on the east. Houston will most likely be east of landfall, but where exactly those spots of 20 or more inches fall are impossible to say. Best guess is south and east of the city, but how far is unknown. It's a huge area and, as we all know, there are days when one part of town gets soaked and another gets nothing. Same here on a larger scale.
As to when, we know the storm will probably make landfall overnight Monday into Tuesday. It will then slow down somewhat leaving a path of rain through Wednesday throughout the region. By Thursday, it should be far enough to the north and east to allow us to dry out.