Category 2 Alex Makes Landfall on the Mexican Coast

Hi, Dr. Rob Carver filling in for Jeff on the late shift.

1AM CDT Update
Alex is weakening as it moves inland As of the 1AM advisory, Alex's winds have slowed to 85 mph. Alex is at 24.1N, 98.2W which is 35 miles northwest of La Pesca, MX and 135 miles south-southwest of Brownsville, TX. Alex is moving west-southwest at 10 mph. Alex may be slowing down, but it's still producing a lot of rain. Radar-derived rainfall estimates shows that Alex is covering widespread areas with 0.5-0.8 inches of rain in the last hour. Over the past 24 hours, the Rio Grande at Brownsville has risen 10 feet, but it's still about 14 feet away from the flood stage of 27 feet.

9PM CDT
The center of Alex's eye has made landfall according to NHC. They state that 9PM CDT, Alex's center crossed the shoreline in the municipality of Soto La Marina, MX, which is 110 miles south of Brownsville. At the time of landfall, Alex had wind speeds of 105 mph, making it a Category 2 storm on the Saffir-Simpson hurricane wind scale

With wind speeds near 100 mph, Alex is nearing landfall on the Mexican coast. As of 8PM CDT, Alex is at 24.3N, 97.5W, 40 miles northeast of La Pesca, MX and 110 miles south of Brownsville. It is moving west at 10 mph, and the center of the eye should arrive onshore around 9PM CDT. Alex has a very large circulation, hurricane force winds extend 70 miles away from the the center, and tropical storm force winds are 205 miles away. A MADIS station located in South Padre Island, TX has reported wind gusts of 60 mph and sustained winds of 35-40 mph. We have a plot of that station's data here, and it looks like the wind speed sensor failed around 733PM CDT. Unfortunately, that's a common fate for weather stations near a landfalling storm.

One of the last eye penetrations of Alex occured at 640PM CDT, and they found an partially complete eye with a 12 mile radius. The minimum central pressure was 948 mb, a 2 mb drop since the 6PM update, and the maximum wind estimate was 94 mph using the microwave radiometer.


Fig. 1Base reflectivity from KBRO showing Alex's eye at 721PM CDT.

Threat from winds
Hurricane force winds are likely taking place along the northeast Mexican coast right now. 25 mph winds with stronger gusts are being reported in the Brownsville area. A tornado watch is currently in place for the south Texas coast. SPC shows there have been 5 tornado reports so far.

Threat from rain
Radar-derived rainfall estimates suggest that up to 9 inches of rain have fallen in some locations near Brownsville, TX. 5+ inches of rain has fallen over a widespread area in the Rio Grande valley. The NWS office in Brownsville is forecasting a total of 6-12 inches rain across the Valley, with 12-15 inch totals possible in isolated locations. Flooding similar to that caused by Dolly in 2008 is expected across south Texas.

Threat from coastal flooding
The NWS is predicting a 3-4 foot storm surge for the coast from Brownsville to Port Isabel, TX. They think the coastal flooding will be limited and not cause significant damage to property along the coast.

Next update
I'll try to edit this blog with updates as more information comes in tonight. Jeff should have a full posting tomorrow morning, and I'll likely have a post describing the flooding at my blog Thursday night.