Texas Weather and Climate: Patterns, Trends, Events and Useful Resources
National Weather Service Austin-San Antonio TX Paul Yura, Warning Coordination Meteorologist Who is the National Weather Service? Who13 is Forecast the National Offices Weather Service? 13 TX Offices 3 NWS River ForecastWho Offices is the National Weather Service?James Paul, ABRFC Service Coordination Hydrologist [email protected]
Jeff Graschel, LMRFC Service Coordination Hydrologist [email protected]
Greg Waller, WGRFC Service Coordination Hydrologist • Run river models • Forecast height/flow [email protected] RFCs provide hydrologic • Compile/estimate rainfall totals support to NWS forecast • Coordinate with water partners offices (USGS, USACE, IBWC) Forecasting the River Heights Minor - Minimal or no property damage - Possibly some public threat or inconvenience
Moderate - Some inundation of structures/roads near streams - May need some evacuations of people /property
Forecast Major Height - Extensive inundation of structures and roads - Likely evacuations of people / property
Measured Height
https://water.weather.gov/ahps/index.php Flood Wave Travel Times “County Warning Area”
33 Counties
7 Day Forecasts
Watches/Warnings
Decision Support to EMCs, Deployments to EOC
Local Research/Outreach
36,000 mi2 NWS Mission: Protection of Life and Property
It Takes Partner Relationships… Emergency Management Media (TV, Radio, Newspaper, Social Media) State/Fed agencies First responders Amateur radio General Public Texas has more flooding deaths than any other state Over half of the flood fatalities in Texas occurred while people were in their car.
Stats will vary by location
Data from NWS National Hazard Statistics Diverse Watershed Characteristics in Texas
Snowpack - Water Supply
Hill Country Hydrology - Flash Flood threats - Rapid River responses - Cycles of Flood/Drought River Basins of Texas
Where and How the Water Flows
Complex flow patterns Types of Flooding
Ponding & Sheet Flow Flooding
Flash Flooding
River Flooding
Coastal Flooding Flood Timeline
Flash or Areal Before Event Onset Flood Flood Warning Flash Flood Advisory Emergency River Flood Warning
Increasing Impact Potential ALL Situations Represent Threatening Conditions to Life and/or Property
Note: Flooding can (and does) occur without a Flash Flood Watch! Its all about Location, Location, Location
30ft - 72 hrs Flash Flood
• Topography River • Urbanization • Soil conditions Flood 30ft - 2 hrs
ATXFloods.com Situational Awareness
ATXFloods.com
Never drive through flooded low water Bexarflood.org crossings! Remember: 6-12-24 Weather Patterns that Trigger Flash Flooding
• Cell Mergers (storms combine) • Training (move over same area) • Stationary (storms don’t move) • Tropical System (efficient rain) • Stalled Weather System • Upstream Rain Events • Combination • Burn Scar Cell Mergers (storms combine)
2.58 inches in 15 minutes 6.13 inches in 1 hour 8.59 inches in 1.5 hours 9.46 inches in 2 hours 13.70 inches in 4 hours 15.31 inches in 5 hours 17.00 inches in 24 hours Training (move over same area)
Multiple Rounds of Storms
• “Train” over the area • Large rain totals • Storms are moving same direction as the upper level winds Stationary (storms don’t move)
Several campsites washed away Tropical System (efficient rain) Hurricane Harvey 2017
• Historic rains 40+ inches • Once in a lifetime? Stalled Weather System Summer Low pressure system stalls 2002 over TX…sits for days
Canyon Lake overflows Upstream Rain Events
Don’t be fooled by good weather / little rain
“Wimberley Event” 2015 Combination (Upstream, Training, Tropical, Mergers)
The “98” Flood…30+ inches / 18 hrs Burn Scar
Vegetation is lost Flash Floods / Mudslides / Landslides Have 3 Ways to Receive Weather Warnings
Mass Notification Weather Apps Weather Radio Television Commercial Radio Social Media WEA Messages Originated by NWS
Controls are in “Notifications” settings page (iphone)
360 characters, Spanish messages
Weather.gov/wrn/wea NWS Mobile Device Webpage mobile.weather.gov
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