As the southern edge of a major storm system moves approaches Houston the western half of the metro area is under severe thunderstorm warning this morning until 5:30am CT.
Area of severe thunderstorm warning in effect through 5:30am CT. (National Weather Service)
In addition to heavy rain (about 0.5 to 1 inch with this line of storms) this means there may be strong winds, hail and possibly even a tornado over a northern part of the city near Spring. I expect the thunderstorm warning area to expand eastward as we get closer to sunrise.
One saving grace from this system is that it continues to steadily move eastward and should move out of the eastern half of the Houston region by 7 or 8 am CT. After the main line of storms moves through we could see some additional scattered showers and thunderstorms later this morning and afternoon. But as for the potential for very heavy rain and severe weather, this is the main event.
We’re starting to see storms fire up in west Texas and Oklahoma which will progressively move eastward across northern Texas later this evening. These storms will likely bring heavy rains, hail and tornadoes to the warning area below, including Dallas-Fort Worth complex. Conditions could get pretty nasty.
Note: This is the first in a series of reports by Matt Lanza that puts the Tax Day floods into perspective, and discusses what Houston should learn from this natural disaster.
On Monday afternoon the Harris County Flood Control District released its first official summary of the historic flooding that occurred last week in the greater region. I’ve read through it and compiled some highlights for here. (You can also view the report yourself in its entirety here). A serious thank you to Jeff Lindner at the flood control district who has worked tirelessly since last week to provide critical, useful, and interesting information to put this event into context and keep the region informed. He is also a must-follow on Twitter if you’re into weather, haven’t done so yet.
Report highlights
Rainfall rates of 1″ in just 5 minutes were observed in Harris County. The maximum hourly rate was 4.7″. The maximum amount in 12 hours was 16.7″
Harris County averaged 7.75″ of rainfall for the event. That’s equivalent to 240 billion gallons of water falling on the area. This exceeded Memorial Day (162 billion gallons) by almost 80 billion gallons of water. That event was more confined, whereas the Tax Day rains were much larger spatially.
Map of 12 hour rainfall totals. Click to enlarge. (HCFCD)
Good morning. Before we move on to the potential for inclement weather later tonight, and again later this week, I wanted to note for the record that there was in fact a tornado in Houston on Sunday evening. The National Weather Service confirmed the touchdown of an EF-0 tornado, with 70-mph winds, in League City. It’s track went for 1.4 miles.
TODAY
It’s a warm and muggy morning, with temperatures only falling into the low 70s out there, and we’re going to see a very warm day in the upper 80s under partly sunny skies. Areas in northern Texas and Oklahoma are likely to see strong storms later today, and quite possibly a number of tornadoes. However I do not believe any of these storms will move into the Houston area today.
WEDNESDAY
Some of the energy from the system over northern Texas should sag southward into the greater Houston area by early Wednesday, or mid-Wednesday morning, however. The best chances for storms should come north of Interstate 10, and the primary threats are wind and hail, with tornadoes a lesser possibility. As for timing, for the metro area I expect any line of storms that does develop to move through between about 6am and noon. We are probably looking at widespread rain totals of 0.5 to 2 inches of rain, with greater accumulations to the north. Isolated areas could see higher rain totals. While these storms have the potential to produce a flooding threat, and I’m not ruling that out, I don’t feel as though most areas will see high enough rain totals. (We will be watching it closely all the same).Some lingering showers are possible Wednesday afternoon.
The potential for storms on Wednesday morning is greatest to the north and northeast of Houston, but that doesn’t mean the city is in the clear. (NOAA)
