Pack an umbrella, folks: Austin and Central Texas are expected to get its second but likely not its last dose of rain for the month on Monday.
"The combination of an upper-level low pressure system, a cold front and remnant moisture from Hurricane Roslyn from the Eastern Pacific will lead to the possibility for isolated strong to severe storms mainly late Monday afternoon and Monday night," the National Weather Service said in a statement Monday morning. "The primary hazard will be strong straight-line winds, but hail up to an inch in diameter along with an isolated tornado may be possible as well."
Tornado watch for Austin until midnight
8:30 p.m. update: A tornado watch is in effect until midnight for the Austin metro area, the National Weather Service said.
The affected areas include Travis, Williamson, Hays, Bastrop and Caldwell counties, as well as neighboring Burnet and Fayette counties.
A tornado watch means residents in the alert should monitor news and weather reports for any indication of a tornado threat and to be prepared to act, forecasters said.
Damaging winds possible with storms
2:45 p.m. update: A wind advisory will be in effect for most of the Austin metro area starting at 11 p.m. Monday and lasting until 9 a.m. Tuesday, the National Weather Service said.
Secure loose objects in your yards and be careful while driving tall vehicles on open roads that will buffeted by the high winds during that time, forecasters warned.
The alert will apply to areas along and west of Interstate 35, including Travis, Williamson and Hays counties as well neighboring Hill Country counties such as Blanco, Llano, Burnet and Gillespie.
During the advisory period, northwest winds will kick up to 20 to 30 mph with gusts as strong as 50 mph expected, forecasters said. Such winds could blow around unsecured objects, the weather service said.
"Tree limbs could be blown down and a few power outages may result," forecasters said, adding that the strong winds will come behind a line of thunderstorms accompanying a cold front.
Watch for squall line storms late tonight
12:30 p.m. update: According to a National Weather Service bulletin Monday morning, Doppler radar images and satellite photos show "pockets of warm advection shower activity moving northeastward along portions of the I-35 corridor and across the Coastal Plains."
Forecasters said they expect the showers to clear out by early afternoon. Ahead of the looming cold front is low atmospheric pressure, a "pre-frontal trough" that is conducive for stormy weather.
"As this pre-frontal trough slides east throughout the afternoon, some of the latest short-term model guidance indicate that there could be the potential for isolated thunderstorm activity ... along the I-35 corridor in advance of the main front, and storm potential for later this evening where a strong cell or two will be possible," the weather service said.
The weather service said its greatest concern about possible severe storms would be "the development of a squall line along the main front this evening through about midnight," adding that "strong damaging straight-line winds remain the greatest threat."
Forecasters are not ruling the chance of an isolated tornado.
"Hail up to or around 1 inch in diameter could be possible as well," they said.
What's the latest forecast?
8 a.m. update: The forecast for the Austin metro area calls for an 80% chance of rain on Monday: Light showers this morning, a possible thunderstorm before 2 p.m. and another round of storms between 2 p.m. and 5 p.m. Up to a half-inch of rainfall is possible, the weather service said.
More:Austin's October has seen historically low rainfall this year. Here's why we should worry.
Monday's high temperature of 85 will be accompanied by south winds of around 10 mph with gusts as strong as 25 mph. At night, a 60% chance of rain will persist with a thunderstorm possible between 11 p.m. and 2 a.m. Up to a quarter-inch of new rainfall is possible.
Overnight temperatures will drop to as low as 55 degrees, thanks to a cold front that will transform balmy south winds into chillier northwest breezes after midnight, forecasters said. Watch for blustery winds Monday night that could include gusts as strong as 30 mph.
The weather service's extended outlook for the week ahead includes the return of sunshine and another shot at rain before the weekend:
- Tuesday: Sunny with a high near 77. Northwest winds of 10 to 15 mph could include gusts as high as 35 mph. At night, clear with a low around 49. North wind around 5 mph becoming calm in the evening.
- Wednesday: Sunny with a high near 79. Clear at night with a low around 52.
- Thursday: Sunny with a high near 81. South-southeast winds of 5 to 10 mph could include gusts as high as 20 mph. A 50% chance of rain at night after 8 p.m. Partly cloudy with a low around 60.
- Friday: A 50% chance of rain mainly before 2 p.m. Otherwise, partly sunny with a high near 73. Another cold front will turn east-northeast winds into gusty north-northwest winds in the afternoon. A 20% chance of rain at night with a low around 54.
- Saturday: Mostly sunny with a high near 72. Clear at night with a low around 50.
- Sunday: Sunny with a high near 76.
