Category 4 Hurricane Harvey Makes Landfall
Saturday 9:45 A.M. Update
***Hurricane Harvey made landfall between Port Aransas and Port O'Connor, Texas around 11 P.M. ET last night as a category 4 hurricane with sustained winds of 130 mph. It was the first category 4 hurricane to make landfall in the U.S. since Charley in 2004. Hurricane Katrina in 2005, which reached category 5 status in the Gulf, weakened to category 3 when it reached land in Mississippi.
The area that experienced the full fury of Harvey (usually situated on the north and northeast side of the track) was sparsely populated, remaining north of the Corpus Christi metro area and well south of the Houston/Galveston area. It struck the San Jose and Matagorda Islands, part of a which is a Wildlife refuge . Some of the larger cities in the direct path of the storm were Port Lavaca and Victoria. Several weather stations were inoperable during the peak winds but a station in Aransas Pass measured a gust of 132 mph as the storm came ashore.
As of mid-morning Saturday the storm had weakened to a category 1 now that it was over land...and would continue to weaken through the day. The problem now for Texas is the rainfall with this system. Unlike most hurricanes that come through fairly quickly...Harvey will stall over the Lonestar State and produce incredible rainfall amounts....possibly over 30" in some locations in the coming days. In fact, the morning's computer model guidance strongly suggests Harvey's remnants stay down in Texas through at least next weekend. This could lead to what the National Hurricane Center is referring to as "catastrophic flooding". While the wind and surge part of the hurricane is abating...the flooding aspect will likely continue for another 7 days at least, and over a much larger area from SW Louisiana down to south Texas.
Our area appears unlikely to see any effects from Harvey until next weekend at the earliest...and even then it's possible what is left stays south of us and dissipates. In fact, neither the GFS (American model) or ECMWF (European model) suggest that Harvey's circulation will get anywhere near us. Some of it's moisture may get drawn into a cold front that could arrive late Sunday or Monday but given that is still 8 days away it can and likely will change.
Hurricane Harvey continued to strengthen overnight and has now strengthened all the way to a category 4 storm on the Saffir-Simpson scale as it makes landfall on the south Texas coast. A category 4 storm has sustained winds between 130 mph and 156 mph with the potential for catastrophic damage. Recent aircraft passing through the storm (which is how storm intensity and structure is measured) indicated a strong air pressure drop...and that is usually followed by an increase in wind.
The storm is expected to cross Matagorda Island late tonight with sustained winds around 125 to 130 mph. Should that track hold, it would put some of the strongest winds of the storm over a fairly sparsely populated area. Nonetheless, a 9 to 12 foot storm surge is projected around Lavaca and Matagorda bays and winds could gust over 100 mph in downtown Corpus Christi. The more lasting threat from the hurricane, however, may be flooding. Once the storm moves inland it will get blocked by an area of high pressure to the north...forcing it to loop around and slowly move back into the the Gulf. By next Wednesday the National Hurricane Center suggests it may still be near Houston! That means several days of torrential rain...and computer model forecasts are suggesting 15 to 25 inch totals will be common across Southeast Texas, with some locations picking up over 30"!!!
The last time a category 4 hurricane made landfall in the U.S. was back in 2004 with Hurricane Charley in Florida. Before that there was Hurricane Andrew which devastated the south Florida coast 25 years ago in 1992 as a Category 5 storm and Hugo which hit South Carolina as a Category 4 hurricane in 1989. Since then hurricane landfalls have been relatively rare and weaker.
With that high keeping the moisture suppressed, our weather pattern locally looks fairly dry, although a weak system will bring some scattered showers Tuesday into Wednesday. Also of note is another tropical system crossing Florida that could become "Irma" this weekend off the Southeast coast. That system, which likely not getting very strong, could bring some rough surf and heavy rain to at least the Outer Banks and Virginia beach early next week before moving away. It would be gone by Labor Day weekend but at that point we may see what's left of "Harvey" moving in from the southwest. It's uncertain how much of the circulation would be left but we could see an unsettled pattern developing by next Friday or Saturday for our area. Stay tuned.