Sunday, February 14 2021 2:00 PM CT

Home , February 14

WINTER WEATHER UPDATE: Extreme Cold and Potential Ice/Sleet February 14-16 2:00 PM CT Sunday, February 14 2021 Prepared by: Barry Goldsmith WFO Brownsville/Rio Grande Valley

Disclaimer: The information contained within is time-sensitive. Do not use after 7 AM CST Monday.

NWSBrownsville www.weather.gov/rgv Situation Overview: The “Skinny” Brownsville/RGV WEATHER FORECAST OFFICE Bottom Lines: ▪ Life-Threatening wind chill (“feels like”) temperature expected Monday, worst between 6 and 9 AM. ▪ Hard and damaging freezes are also likely Monday and Tuesday mornings. Coldest “night/day/night” period since Dec. 1989 ▪ A period of freezing rain (glaze ice) will turn over to ice pellets, perhaps ending with a few snow flurries, between this evening and just after daybreak Monday morning ▪ The ice may coat surfaces prior to the sleet (pellets)…coldest temperatures following end of precipitation may produce a dangerous “flash” freeze ▪ Through Tuesday, temperature will range from 25 to 35 degrees below average, possibly as much as 40 degrees below average Monday morning through Tuesday afternoon. Average is 75 by afternoon, 52-55 by daybreak. ▪ Much below average temperatures are now guaranteed through the end of next week (February 19) Forecast position of arctic high (US model, top) and “expected” forecast and departure from average for minimum temps Feb. 15 morning. 2/14/2021 2:53 PM www.weather.gov/rgv Rio Grande Valley/Deep S. Texas Outlook Brownsville/RGV Life-Threatening Wind Chills, a Hard Freeze, and Ice/Sleet WEATHER FORECAST OFFICE Sunday Night Tuesday Morning • Freezing/Frozen Precipitation (ice, then • Hard Freeze potential for many sleet) Develops soon after sunset through mid morning…17 to 25˚ ranchlands; mid to late evening Valley • Even with lighter winds, “feels • “Feels Like” temperatures falling to 10s- like” temps 6 to 18˚ by 7/8 AM 20s˚ after midnight; 10-15 by sunrise. • Slow recovery by afternoon (upper 30 to mid 40s)

Sunday Night Monday Tuesday Feb 13 Feb 14 Feb 15 Feb 16

Monday • Likelihood for Minor Icing and Sleet through Pre- Dawn west, 8/9 AM near Coast. “Flash” Freeze Morning Possible • “Feels Like” Temperatures droping to 8 to 18˚ from dawn-9 AM. Could be as low as 5˚ • Actual temperatures falling to 21-28˚ by 7 AM but Late Morning/ could be as low as 18-25 by 8 AM; low-mid 30s after Aftn noon Valley with at or just below 32˚F ranchlands 2/14/2021 2:53 PM www.weather.gov/rgv Forecast Situation – Deep Freeze Brownsville/RGV Sunday through Tuesday, Feb 14-16 WEATHER FORECAST OFFICE • Tonight/Early Monday (Feb 14-15): • Arctic “blast” surges in between 6-7 PM and 3 AM • Rain beginning to freeze (ice up) as early as sunset N. Zapata east to N. Kenedy; light sleet (ice pellets) between midnight and daybreak • Rain beginning to freeze (ice up) between 9 PM-midnight for the Rio Grande Valley – but sleet could also occur in theValley by 3 AM • Temperatures crashing from 34 to 39 at 6 pm to between 22 and 27 between 6 AM and 9 AM Monday. Potential for upper teens to mid 20s (all areas; coldest N. Zapata, Jim Hogg, Brooks, Kenedy, Willacy, N. Hidalgo) • “Feels Like” Temperatures expected to be 8 to 18˚F, coldest near coast and across ranchlands. Could be as low as 5˚F Harlingen-Bayview! • Untreated roads will be very dangerous in this scenario for the Monday commute! A “flash freeze” could occur immediately after precipitation ends and temperatures bottom out. • Monday Afternoon (Feb. 15) – Actual temperatures forecast to rise slowly and get above freezing by noon, but range from 29 to 35 by mid afternoon. Potential for readings to remain below freezing Zapata through Kenedy – “Feels like” temperatures only rising to 12 to 25˚F, coldest toward the coast • Tuesday (Feb 16) – Another hard freeze for all of the Rio Grande Valley/Deep S. Texas region; morning lows between 17 and 25˚F. If skies stay cloudy, temperatures would be not as cold (20s) but still a hard freeze for most. – A slow rise in temperatures, getting above freezing by noon

2/14/2021 2:53 PM www.weather.gov/rgv Potential Impacts – On Land Brownsville/RGV February 14 late evening - February 16th noon WEATHER FORECAST OFFICE • Dangerously cold for persons exposed to the elements without adequate clothing or shelter. Critical danger for frostbite and death from 12 AM to Noon Monday, and midnight to 9 AM Tuesday. • High use of heating could stress the local and statewide power grid, with potential neighborhood outages. Peak potential: 12 AM Monday through 12 PM Tuesday. • House fires could start from incorrect use of space heaters or other non- traditional heat sources • Potential for pipe bursts in residences and water main breaks in communities due to extreme cold • 12 AM Monday through 12 PM Monday: Potential for very dangerous driving conditions on untreated roads due to the combination of light freezing/frozen precipitation and temperatures in the 20s.

2/14/2021 2:53 PM www.weather.gov/rgv Potential Impacts – On Water Brownsville/RGV Through Tuesday, February 16th WEATHER FORECAST OFFICE

• 12 AM Monday through 12 AM Tuesday - Over Laguna Madre and the Gulf: Likelihood of a Gale event with strong winds over 40 knots and very high and extremely rough seas – Beaufort Scale 8 – from 12 AM Monday through 12 AM Tuesday (longest over the Gulf) • 6 AM Monday through 9 AM Tuesday: Over Laguna Madre and Gulf: “Sea Smoke” may form due to the very cold air overrunning the warm sea surface, reducing visibility below 1 nautical mile. Freezing Spray possible along Laguna Madre. • Through the Period: Coastal waterways – Pelicans may become trapped along Padre Boulevard especially Sunday night through Monday evening. Sea turtle “stunning” is likely, peaking Monday through Wednesday

2/14/2021 2:53 PM www.weather.gov/rgv Winter Storm/Wind Chill Warning Corpus Christi WEATHER FORECAST OFFICE

• Best Prospect for more Precipitation: Jim Hogg-Kenedy • **ANY** Glaze Ice at forecast temperatures (low to mid 20s) is dangerous!! • Sleet is now expected in all areas, but glaze ice will likely coat untreated surfaces underneath any sleet accumulation • A Hard Freeze (27 or lower for several hours) Is Expected for al but the Barrier Island (Still a Freeze).

www.weather.gov/CorpusChristi Ice/Sleet Accumulation Map Corpus Christi WEATHER FORECAST OFFICE

Best Timing Estimate: • RG Plains/Upper Valley – Starting after sunset, ending by 2/3 AM • Brooks/Mid Valley: Starting 6-9 PM (Brooks); 9- Midnight (Hidalgo), ending 4-6 AM • King Ranch/Lower Valley: Starting 6-9 PM (Kenedy, possibly Willacy; 9-Midnight (elsewhere except near coast); ending 6-8 AM

All Areas: Brief period of Icing (Freezing Rain) followed by Ice Pellets (Sleet)

www.weather.gov/CorpusChristi Wind Chill Forecast Maps Brownsville/RGV WEATHER FORECAST OFFICE

Could be lower than shown Harlingen-Brownsville to Laguna Winds will be lighter (5-10 mph), but temperatures lower, hence Madre if winds stronger/temps lower. 8 to 12˚F possible by 8 AM. Similar wind chill readings to Monday. Highest in LowerValley/toward coast. 2/14/2021 2:53 PM www.weather.gov/rgv Safety Infographics – Hypothermia Brownsville/RGV Sunday, Feb 14 10 PM through Tuesday, February 16 Noon WEATHER FORECAST OFFICE

2/14/2021 2:53 PM www.weather.gov/rgv Safety Infographics – Heaters Brownsville/RGV Through Tuesday, February 16th, and Beyond WEATHER FORECAST OFFICE

2/14/2021 2:53 PM www.weather.gov/rgv Safety Infographics – Driving Brownsville/RGV February 14-15 (10 PM to Noon) WEATHER FORECAST OFFICE

These tips also apply for light ice pellets (sleet)

We strongly urge everyone to remain off the roads Monday, at least through noon.

2/14/2021 2:53 PM www.weather.gov/rgv Safety Infographics – Dressing Brownsville/RGV Through Sunday, February 14 and beyond WEATHER FORECAST OFFICE

“Extreme Cold” – Late Tonight Through Tuesday Noon

2/14/2021 2:53 PM www.weather.gov/rgv Safety Infographics – Four P’s Brownsville/RGV Through Sunday, February 14 and beyond WEATHER FORECAST OFFICE Protect People! Check on the elderly/infirm and other persons without heat, and ensure they have a safe, warm place to be this weekend. Check for open shelters in your community.

Protect Pets! Bring house pets indoors especially This evening through Tuesday, when freezing temperatures are most likely and they could be injured or die. Ranchers…finalize livestock protection, too!

Protect Plants! Cover, or move indoors, new vegetation or tender tropical plants no later than sunset to be on the safe side.

Protect Pipes! Cover (insulate) outdoor or exposed pipes not later than sunset. Consider a slow drip of water overnight through Tuesday noon.

2/14/2021 2:53 PM www.weather.gov/rgv Safety Infographics – Pelican Watch Brownsville/RGV Through Sunday, February 14 and beyond WEATHER FORECAST OFFICE

Pelicans flying toward Bahia Grande, through Saturday and again Sunday night-Monday

2/14/2021 2:53 PM www.weather.gov/rgv Record Cold Forecast! Brownsville/RGV February 16 Low (Minimum) Temperatures WEATHER FORECAST OFFICE

2/14/2021 2:53 PM www.weather.gov/rgv Key Take-Aways Brownsville/RGV WEATHER FORECAST OFFICE ▪ Prepare for a prolonged period of cold weather, with greatest danger potential from Sunday overnight through Tuesday noon (Feb 14-16) ▪ Duration of freezing (≤32˚F) Monday into early Tuesday could range from several hours to more than a day across ranch country, which would be the most since February 2-4, 2011’s ice storm event ▪ Duration and intensity of the cold will determine the extent of any agricultural and livestock damage, especially coming this late in the season ▪ We strongly urge getting at-risk people to heated locations by sunset, and all to remain off the roads Monday morning (at least): Empty roads are Safe roads!

2/14/2021 2:53 PM www.weather.gov/rgv The Next Briefing: 2-3 PM CT Monday, February 15 Method: Email

Web: http://weather.gov/rgv Facebook: NWSBrownsville

Phone: (956) 504-1432 x2 Twitter: NWSBrownsville

E-mail: [email protected] YouTube: NWSBrownsville

@NWSBrownsville www.weather.gov/rgv