Weather and Society Watch
The Use of Innovative Communications to Enhance Weather Information for a Rare Winter Storm in South Texas
by Barry S. Goldsmith*, Mike Buchanan**, Scott Cordero***, and John Metz****
From late February 1 - February 4, 2011, significant winter weather impacted nearly 2 million people from the Coastal Bend to the Rio Grande Valley in South Texas, a region known for warm winters. Long durations of frigid temperatures culminated with a prolonged period of freezing rain, which covered exposed surfaces with up to 3.8 cm (1.5 in.) of ice. The widespread icing was the first such event for South Texas in over 20 years, and required a much higher level of decision support due to increased population and impacted infrastructure, including roads, businesses, schools, and health facilities. The National Weather Service (NWS) offices in Corpus Christi and Brownsville used innovative methods and trusted relationships to communicate the threat to emergency management, public health, public safety, and transportation, education, and media partners several days in advance. Early warning resulted in decisions that likely saved lives and mitigated significant economic loss.
A strong cold front swept across South Texas on February 1, followed by a sprawling arctic high pressure ridge, which spread from western Nebraska and eastern Wyoming southward through Texas. By daybreak on February 2, temperatures ranged from -5°C (23°F) at Beeville to 1°C (34°F) at McAllen. Temperatures would remain near freezing (0°C) through the daylight hours of February 2 under a steel-gray overcast, dropping below 0°C in all areas by midnight LST (06 UTC) on February 3.
The approach of an upper level disturbance lifted a limited amount of low level moisture into light precipitation, starting around 7:30 a.m. (1330 UTC) on February 3 near the Lower Rio Grande Valley coast and spreading north and west through the day and overnight, eventually covering all of South Texas with a coating of ice. The freezing drizzle continued for up to 24 hours in some locations. Temperatures remained at or below 0°C for at least 30 hours in South Texas—up to 60 hours in some locations between February 1 and February 4. Ice accretion ranged from 1 cm (0.375 in.) across the Coastal Bend near Corpus Christi, to 3.8 cm (1.5 in.) in Brownsville. Most of the ice accumulated on exposed surfaces, including elevated roadways, bridges, power lines, trees, and grasses.
The long duration freeze and icing caused an estimated $11 million in reported crop damage, particularly to sugar cane. Ornamental, unprotected tropical plants were heavily damaged. Rolling blackouts across the state of Texas were implemented through the arctic outbreak and winter weather to prevent long term outages. Power outages peaked at 65,000 residences. There were nearly 200 reported vehicle accidents on state and federal highways in the Rio Grande Valley; dozens of persons were admitted to local hospitals with injuries from the accidents, and there was one fatality from a vehicle rollover. Dozens more persons suffered minor injuries from slips and falls on the ice.
The NWS offices in Corpus Christi and Brownsville utilized an array of Internet-based communication tools available to their employees and to decision makers in public safety, public health, education, transportation, and the media to provide a continuous stream of weather information, from the planning stages through the entire event. Decision makers were notified a week prior to the event with “heads-up” email messages describing the expectation for a long duration freeze, dangerous and potentially life-threatening wind chill, and increasing confidence for a wintry precipitation mix beginning on February 3. The email notices were supplemented by the following communications at each office:
NWS Corpus Christi added the following innovations:
NWS Brownsville/Rio Grande Valley added the following innovations:
Traditional communications were also used by each office prior to and during the event. These included the official outlook, watch, warning, and advisory text products starting with Public Information Statements on January 30 and continued with Freeze Watches/Warnings and Winter Weather Watches/Warnings/Advisories as the event approached. A Local Area Emergency was issued by the City of Corpus Christi Department of Emergency Management to heighten awareness for life threatening road conditions during the peak of the storm. NWS Corpus Christi relayed the message through the Emergency Alert System, ensuring wide distribution to the general public. Dozens of telephone, radio, and television interviews were conducted. Local Storm Reports (LSRs) were issued in near real-time to update primary media partners on icing conditions, in case innovative communications failed or were not available.
Prior to the current emphasis on weather decision support, the process for meeting the NWS stated mission of “providing…warnings…for the protection of life and property and the enhancement of the national economy” at the local level was predominantly a one-way street driven by government meteorologists issuing ALL CAPS text “products” in a fairly technical language, often assuming that decision makers and other listeners and readers would be able to comprehend the message to carry out their missions in ample time to protect life and property in their communities. Metrics used to define the effectiveness of warning texts included “lead time”, calculated solely on the time the text was issued to the time the first verifying data were observed by trained weather spotters or other trusted sources.
For a significant winter weather event, a lead time of 12 to 18 hours from the first warning message may be considered sufficient from the meteorologist's viewpoint. To the community, that same lead time may be perceived as insufficient. The time required to bring in additional staff and equipment to prepare roads for ice and snow, prepare public utilities for potential power outages, and cancel early morning school bus runs can be longer than 12 hours. Infrastructure preparation, public comprehension and preparedness actions, and overall awareness of the threat are critical to a successful outcome on society.
New tools, techniques, and trust relationships are being implemented throughout the NWS to improve real-world communication well before the first snowflake falls, the first tidal surge arrives, or the explosive growth wildfire is sparked. Objective data and anecdotal evidence from South Texas decision makers involved with the February 1-4, 2011, winter weather episode suggested the NWS focus on advance communication of potential weather hazards, well beyond the typical watch/warning “lead time”, paid dividends and saved life, property, and money.
Independent school district officials who used webinar and email information from NWS Brownsville/Rio Grande Valley were able to close school the night before the arrival of glaze ice in the Cameron and Willacy County on February 3; officials in Hidalgo County elected to hold classes during the morning of February 3, with plans ready for staggered early dismissal based on the forecast arrival of icing later in the day and through continuous contact with staff early in the morning. Public safety and public works personnel were ready to treat and close roads a day before glazing began, and hospitals were staffed in advance to handle additional patients injured in vehicle accidents or from slipping. Airports and sea ports from the Rio Grande Valley to the Coastal Bend prepared for rare de-icing, and moved aircraft and other ice sensitive equipment indoors prior to the onset of freezing rain.
There were nearly 200 vehicle accidents, dozens of accident related injuries, and at least one driving fatality on February 3 across the Rio Grande Valley. Objective data and anecdotal evidence suggests those numbers would have been substantially higher had the Rio Grande Valley not been effectively “shut down” for commerce and education due to advance NWS decision support.
Early February traffic volume across the Rio Grande Valley is among the highest of any time during the year. Local travelers, seasonal residents, and transmigrants combine for more than 100,000 vehicles on elevated highways and interchanges per day. The Annual Average Daily Traffic (AADT) count for Hidalgo County between Weslaco and the Highway 281/Highway 83 interchange (McAllen/Pharr) exceeds 100,000 vehicles, with 131,000 vehicles at the interchange itself (Texas Department of Transportation, 2009). The potential for thousands of accidents is very high on these elevated roads in a region where winter driving is almost never necessary.
Coordinated preparedness actions by jurisdictions from the Rio Grande Valley to the Coastal Bend, triggered by NWS decision support services, reduced the number of travelers on and February 3 and 4 to a small fraction of average. Such reductions may have saved lives, as well as millions of dollars in repair or recovery costs to vehicles and highway infrastructure. Millions more in medical expenses may have been saved by reducing the potential number of critical human casualties in vehicle accidents.
This event, and catastrophic events that followed across the United States through spring and summer of 2011, show the importance of hazardous weather communication to an increasing number of decision making stakeholders. The shift toward synergistic weather information sharing among stakeholders has been aided by the 21 st century communication technology revolution. Innovative approaches to providing this information, from plain language confidence forecasts by trusted NWS employees to the technological tools that allow an increasingly diverse universe of decision makers is making a difference. Evidence from the South Texas winter weather events of February 1-4 showed success in the mission of protecting lives, property, and the economy—a mission that defines all who provide weather information for a safe, healthy, and productive society.
* Barry S. Goldsmith (email@example.com) is the Warning Coordination Meteorologist for the National Weather Service Forecast Office in Brownsville, Texas.
** Mike Buchanan (firstname.lastname@example.org) is the Science and Operations Officer for the National Weather Service Forecast Office in Corpus Christi, Texas.
*** Scott Cordero (email@example.com) is the Meteorologist-in-Charge for the National Weather Service Forecast Office in Corpus Christi, Texas.
**** John Metz (firstname.lastname@example.org) is the Warning Coordination Meteorologist for the National Weather Service Forecast Office in Corpus Christi, Texas.
Figure 1. A portion of the front page of the NWS Brownsville/Rio Grande Valley web site. From top: Winter Weather Update “breaking news” banner headline, which linked to event blog (see Figure 2); Top News of the Day preparedness and safety information; graphical depiction of current conditions and forecast hazards.
Figure 2a. Sample from Winter Storm web log, February 3rd and 4th, 2011, WFO Brownsville/Rio Grande Valley.
Figure 2b. This entry shows Warning Coordination Meteorologist Barry Goldsmith with an “ice dagger”, and explained how dangerous these could become as melting began.
Figure 3. Image of snow (nieve) and ice (hielo) forecasts from briefing provided to Spanish language media and other partners by NWS Corpus Christi, Texas, during the winter storm of February 3rd and 4th, 2011.
Figure 4. Front web page of The McAllen Monitor (Newspaper) website, showing NWS Brownsville/Rio Grande Valley winter storm graphic as featured story of the day, February 2nd, 2011. The use of NWS graphics and information dates back to 2009, agreement was reached to allow use of NWS Brownsville/Rio Grande Valley web graphics with credit provided.
Photo 1: Sign in Brownsville showing melting ice soon to crash onto the ground during the early afternoon of February 4, 2011. (Credit: Jim Campbell, NOAA/NWS)
Photo2: Iced fields and woods around the Brownsville/South Padre Island International Airport on the morning of February 4, 2011. (Credit: Brownsville/South Padre Island International Airport)