Winter Weather Update Houston/Galveston Monday February 15th, 2021 Overview: Dangerous Cold, Icy Conditions. More Ice Especially Northern Zones Wednesday ● Life-Threatening Cold: Temperatures today will stay in the teens with chill indices near zero. Tonight temperatures will drop to near zero NW, around 10 Greater Houston, teens Galveston . Continued risk of burst pipes, damage to infrastructure. Risk of hypothermia to those caught outside. Concern for people without heat, power.

● When Will it Melt?: Temperatures will likely stay below freezing for northern zones until Friday. For Houston and points south will rise a little above freezing Wednesday but still cold. Would expect little or no melting until temperatures rise above freezing.

● Next Storm Wednesday: Another storm Wednesday will bring a round of rain, south, freezing rain north. Dividing line still uncertain but most of the freezing rain/ice with this next system looks to be northern half. Will depend on surface temperatures. Weather Conditions at Noon Monday Very cold!

Temperatures mainly around 20 immediate coast, teens elsewhere, 10 to 12 NW. Some Sunny Breaks but Also Snow Flurries in Bands Coming Off Warm Bays, Lakes

Some sunny breaks.

Cloud bands producing snow flurries some spots.

Similar to Lake Effect Snow bands that occur most commonly Great Lakes. Watches, Warnings, Advisories Many winter hazards.

Dangerous cold, low wind chills, icy roads. Hard freeze.

Gale Warning coastal waters; low water advisory.

Next storm to bring more ice to northern counties! Min Temperature Forecast Temperatures dropping tonight to near zero Bryan College Station and Madisonville, closer to 10 degrees Greater Houston, upper teens Galveston.

Low Temperature Tuesday Morning Wind Chill Temperature

Wind chill temperatures today through Tuesday morning near zero many spots, below zero N and NW of Houston.

Mon Night/Tuesday Morning Ice Accumulation Forecast from Wednesday System (from Freezing Rain)

Will likely see freezing rain, icing, mainly north of I-10 on Wednesday.

Greatest threat for significant additional icing the farther north you go.

Southern counties more of a cold rain Wednesday but will need to watch out for icy patches at night as temps fall back below freezing. Bryan/College Station https://www.weather.gov/forecastpoints (click on point on map) https://go.usa.gov/xsCPw

Bitterly cold tonight and Tuesday.

Lows near zero tonight, wind chills mostly below zero.

Concern for more freezing rain starting late Tuesday night but especially Wednesday Houston/Harris Co https://www.weather.gov/forecastpoints (click on point on map)

Temperatures holding in the teens today, dropping to high single digits tonight. Would expect very little melting through Tuesday night.

Temperatures recovering to above freezing Wednesday. Period of cold rain, possibly beginning as freezing rain.

Another cold day and night Thursday.

Finally a warming trend Friday and weekend. Highs 40s Fri, 60s Sat and Sun Galveston https://www.weather.gov/forecastpoints (click on point on map) https://go.usa.gov/xsCyc

Bitterly cold Monday tonight and Tuesday with lows in high teens.

Should warm above freezing before next storm arrives Wednesday. Just rain for Galveston. Precipitation Type Maps GFS Model Note precipitation type with next system in GFS at 9 am and 3 pm. Period of freezing rain north. Southern extent of freezing rain uncertain, especially at onset. Could extend down to 1nterstate 10.

GFS Model 9am Wednesday GFS Model 3 pm Wednesday Precipitation Type Maps ECMWF Model Note precipitation type with next system in ECMWF at 6 am and Noon Wednesday. Period of freezing rain north. Southern extent of freezing rain uncertain, especially at onset. Could extend down to 1nterstate 10.

6am Wednesday Noon Wednesday Weather Forecast Office 7-Day Weather Outlook Marine Hazards Houston/Galveston, TX Feb 15 – Feb 21, 2021 Issued February 15, 2021 12:42 PM CT Forecast Highlights/Concerns Water Temp ▪ Warning in effect through this afternoon. Elevated /seas Rise: 0657 thru Thurs. Morgans Point 47° Set: 1809 ▪ Snow showers possible in bands. Galveston ▪ Freezing spray a threat thru Tues afternoon. 47°

▪ Low water in the northern bays. 20 nm south of Rise: 0926 Galveston 56° ▪ Dangerous sub-freezing weather. Tonight/Tuesday morning the Set: 2154 coldest with temps in the teens along the coast & wind chill values 60 nm south of 68° near or below 0°F. Freeport

Thresholds Mon 2/15 Tue 2/16 Wed 2/17 Thu 2/18 Fri 2/19 Sat 2/20 Sun 2/21 Temps 15-25 <35° or >97° Temps WC <5 Precipitation >50% am pm Winds >25 kt Gale Gulf Gulf Seas >6 ft Water Levels > 3.5 or <1 MLLW Low water bays Low water bays Ceilings <1000 ft Visibility < 2 miles Sea smoke San Jac River Flood stage Buffalo Bayou stage Legend Uncertainty - worth monitoring Approaching Thresholds Exceeds Thresholds @NWSHouston weather.gov/Houston Summary, Potential Impacts ● Life-Threatening Cold: Temperatures today will stay in the teens with wind chill indices near zero. Tonight temperatures will drop to near zero NW, around 10 Greater Houston, teens Galveston . Continued risk of burst pipes, damage to infrastructure. Risk of hypothermia to those caught outside. Concern for people without heat, power.

● When Will it Melt?: Temperatures will likely stay below freezing for northern zones until Friday. For Houston and points south will rise a little above freezing Wednesday but still cold. Would expect little or no melting until temperatures rise above freezing. Even after partial daytime melting midweek for some areas, watch out for refreeze at night through Thursday night.

● Next Storm Wednesday: Another storm Wednesday will bring a round of rain, thunderstorms south, freezing rain north. Dividing line still uncertain but most of the freezing rain/ice with this next system looks to be northern half. Will depend on surface temperatures which may still be around freezing even as far south as Metro Houston . Next Briefing

● NWS will continue daily briefings through at least Wednesday. at 1 pm. weather.gov/houston @NWSHouston https://www.weather.gov/forecastpoints https://digital.weather.gov/

Questions?