Potentially historic arctic outbreak could bring significant impact
By Jeff Lindner, Director Hydrologic Operations Division/Meteorologist for Harris County Flood Control District
A potentially historic arctic outbreak nears with likely memorable significant impacts and long-duration hazards and challenges. A major winter storm looks to impact nearly all of Texas on Monday, resulting in widespread travel disruption which has the potential to strand travelers on interstates.
Maximum cold weather preparation MUST be completed for this cold outbreak to attempt to mitigate significant infrastructure and property damage.
Modified arctic air mass continues to filter into the region off fresh ice cover over central and north Texas where significant impacts occurred yesterday. Freezing temperatures extend from NW of Huntsville to around Brenham and then back toward San Antonio.
Light rain and drizzle will continue this morning over the area with some decrease this afternoon (this will be the opportunity for road crews to begin pretreatment operations). No real change in the air mass through Sunday morning with the freezing line moving southward over the area each night and creeping back NW during the day. Residents will need to keep an eye on where the line pushes each night as areas north of the freezing line could see some minor freezing rain or freezing drizzle on Saturday and Sunday.
Residents will also want to keep an eye on the next disturbance that will approach the region on Saturday afternoon and evening. Short-range models are coming in a bit stronger with this disturbance and that could result in a bit more showers and rain than currently in the forecast for Saturday afternoon and evening and will need to keep a close eye on the freezing line Saturday night for any southward adjustments.
“True” arctic air mass builds down the plains and this is the region with temperatures falling into the 20’s for most areas. A strong upper-level short wave trough will approach from the west late Sunday and induce a surface low over the NW Gulf helping to draw the cold air southward and increasing winds over the area.
Precipitation is likely to start Sunday evening and overspread all of the region Sunday night into Monday. Predictions still include all P-types (freezing rain, sleet, and snow) and it is certainly possible that any one location may see all three types on Monday. With surface temperatures falling into the mid 20’s on Monday, accumulation is likely.
Travel will become nearly impossible over the region Sunday night-Monday and likely extending into Tuesday as precipitation coats and accumulates on all surfaces … including surface streets.
Potentially record cold as skies clear and ice/snow on the ground will result in an absolutely impressive cold. Predicting 10’s in all areas and 20-25 on the beaches and then 1’s mainly north of HWY 105. This will be extremely damaging temperatures for the area and widespread challenges are likely. Predicting low 10’s north of I-10 in Harris County and mid to upper 10’s over the coastal and southern part of the county. Some locations may near or exceed daily record lows and approach all-time record lows.
Many areas will likely experience between 24-74 hours at or below freezing and the long duration of the sub-freezing temperatures combined with the extreme cold will make impacts long-lasting.
It cannot be stressed enough the need for maximum cold weather preparations to help mitigate significant property damage.
Protect all and any exposed pipes, shut off and drain sprinkler systems. Open cabinet doors and closet doors to get as much heat against outside-facing wall pipes as possible starting Sunday night. In some cases, the best course of action may be to shut off water to a structure and drainpipes overnight when water usage is low to avoid pipes freezing and bursting.
Heavily cover and protect any tropical vegetation, citrus, or vulnerable plants. Given the intensity and depth of the freezing conditions, this will likely be a killing freeze for much of the tropical landscape of this region.
Pets and livestock should have proper shelter, feed, and water. Normal water supplies will likely freeze over including stock ponds and lakes. Persons should plan to limit outdoor exposure Monday and Tuesday as wind chills will be dangerously cold for our region. Prolonged exposure could result in frostbite and hypothermia.
Today: Cloudy with a 30% chance of mainly morning light rain and drizzle. High in the mid 40’s. N wind 10-15mph
Saturday: Cloudy with a 30% chance of light rain or drizzle. Low in the mid 30’s and high in the mid 40’s. N wind 10-15mph
Sunday: Cloudy with a 40% chance of light rain or drizzle early then a chance of freezing rain and sleet by evening. Temperatures in the low 30’s near sunrise. N wind 15-20mph. Wind chills in the 10’s and 20’s.
Monday: Cloudy with an 80% chance of freezing rain, sleet, and snow. Temperatures steady in the mid 20’s. N wind 15-25mph. Wind chills in the 10’s.
Tuesday: Partly cloudy with a low in the low to mid 10’s and high near 30. N wind 5-10mph. Wind chills 1’s.
Wednesday: Cloudy with a 60% chance of precipitation. Low in the mid 20’s and high in the mid 30’s. NE wind 10-15mph.