NWS GSP Hydrology Products Review and Application NWS

NWS GSP Hydrology Products Review and Application NWS GSP Integrated Warning Team Meeting Charlotte, NC October 25, 2016

Hydrology Products 1 2 WFO Greenville-Spartanburg Outline Preparation Products Take-Action Products Flood a a. Hydrolo b. Flood c Flash Watch gic Outlook b. Flood c Flood Watch d Flash Flood Advisor Warnin Emerge y g g ncy & Severity & Lead Typical product severity lead time Time 3 4 Products & Streamgauges a River b Flash Flood Fcst Gauges 2016 Integrated Warning Team Meeting – Charlotte

Hydrology Products WFO Greenville-Spartanburg Preparation Products: Summary Product s Hydrologic Outlook Flood Watch Flash Flood Watch Purpos e Alert public/partners of Inform public/partners of of rapid of significant heavy Flashincreased TAKEAWAY: Floodlikelihood Watches areincreased morelikelihood commonly “slow” (>6 hrs) stream & (<6 hrs) stream & overland rain & flood potential issued for W NC, Upstate SC, and NE GA due to flooding overland flooding; flash flooding; mainstem 24 -48 hours to 7 days threat lower, not zero. possible, but secondary. in advance of event topography andbut urban influences. Content s Headline; Synopsis; Affected Nearly identical to Flood Headline; Expected Regions/Counties; Rainfall & Timing; but mainstem flooding TAKEAWAY: Flood/Flash Flood. Effective Watches. Watch, highlight the area Time; Antecedent Conditions; may not be expected or Weather Synopsis; forecasters think flooding is most doesdue NOT mean Mainstem Floodinglikely Details; . This prioritized to more Antecedent Conditions; Impact & Action convective event. Impacts & Severity areas outside of the watch will. Statements be flood-free, justnature that ofthe Desired Respon se Monitor latest forecasts; initial preparation for flood. TAKEAWAY: prone areas; know warning response; begin coordination predicted threat is lower. Similar to Flood Watch, but Closely monitor weather & river forecasts; finalize prep be aware increased likelihood & warning action plan for of rapid flooding may require Flood and Flash Flood Watches differentiate flood-/slide-prone areas; an adjusted response plan. assess travel/event betweenplans; enhance coordination response times, NOT the severity of flooding. Prepare – Take Action – Severity & Lead Time – Products &

Hydrology Products WFO Greenville-Spartanburg Take-Action Products: Summary Product s Purpos e Desired Respon se Impacts Flood Advisory Flood Warning Flash Flood Warning Emergency Warn public/partners Alert public/partners of “slow” (>6 hrs) of nuisance flooding Credit: NCDOT minor, mod, major, and/or streams just or record stream & out of their banks overland flooding Warn public/partners of rapid (<6 hrs) minor to record flooding Elevate ongoing event for catastrophic rapid flooding; urge immediate life-saving measures Use caution when driving; take property precautions; be alert/ready/prepared for more serious flooding (warnings) Assess risk; move property to higher ground; Turn Around, Don’t Drown; obey barricades & official evacuations Seek higher ground NOW; Turn Around, Don’t Drown; obey barricades; avoid flood-prone areas, crossings even if dry. Avoid warned area; strongly discourage travel within area; obey local official evacuations, orders (State of Emergency) Flooding from clogged or poor storm drainage; ponding within low-lying areas; minimal flooding of farmlands Wide-ranging based on severity of flood; can include widespread/deep overland, road, & structure flooding Rapid flooding of Numerous swift water smaller streams; sig. rescues & road/bridge overland flooding & washouts; significant road closures; iso/scat structure flooding; Credit: NC National Guard evacuations; Credit: structure flooding & USGS ongoing road washouts sig. dam failures Prepare – Take Action – Severity & Lead Time – Products &

Hydrology Products WFO Greenville-Spartanburg Take-Action Products: Summary Product s Purpos e Desired Respon se Flood Advisory Flood Warning Flash Flood Emergency TAKEAWAY: Diversity of flood products exists to help provide an appropriate level of risk assessment and response to a diverse range of flood types based on severity and response time. Impacts Prepare – Take Action – Severity & Lead Time – Products &

Hydrology Products WFO Greenville-Spartanburg Severity and Lead Time 5 -7 hours Flash Flood 30 min FFE Emergency Warning Product Flood Moder ate 24 hrs 48 hrs FFW Major Flash Flood 2 hrs Flood Warning Flood Advisory Flood Watch Flash Flood Watch Minor Flood Advisory Hydrologic Outlook Severity Lead Time from Rainfall Onset Prepare – Take Action – Severity & Lead Time – Products &

Hydrology Products WFO Greenville-Spartanburg Products and Streamgauges: River Forecast Gauges Hydrographs, Impact Statements, Crest History, Photos: http: //water. weather. gov/ahps 2/index. php? wfo=gsp For a given crest… Flood Warning Hydrologic. Outlook (FLW) Flood Advisory (FLS) Impact Verification: 1) Call media, Impact Verification: 1) Call EMs, media, etc. and. EMs, review socialetc. Flood and review social media; 2) perform site Watch media; 2) perform site visit/flood survey; 3) adjust impacts and Watch visit/flood stages assurvey; needed 3) adjust impacts and flood stages as needed Prepare – Take Action – Severity & Lead Time – Products &

Hydrology Products WFO Greenville-Spartanburg Products and Streamgauges: Flash Flood Gauges Hydrographs, Impact Statements, Crest History, Photos: http: //water. weather. gov/ahps 2/index. php? wfo=gsp For a given crest… Flash Flood Emergency F F W Flash Flood Watch Transition to Flood Warning or Advisory if other flooding remains in area Flash Flood Warning (FFW) Flood Advisory (FLS) Impact Verification: 1) Call EMs, media, etc. and review social media; 2) adjust impacts and flood stages as needed Prepare – Take Action – Severity & Lead Time – Products &

Hydrology Products WFO Greenville-Spartanburg Products and Streamgauges: Takaways Hydrographs, Impact Statements, Crest History, Photos: http: //water. weather. gov/ahps 2/index. php? wfo=gsp TAKEAWAY: Please share stream-based impacts with us to help us improve our impact statements and warnings! TAKEAWAY: Nearest forecast points to Charlotte: South Fork Catawba River at Lowell; and Rocky River at Norwood Forecasts provided by the Southeast River Forecast Center in Peachtree City, GA (www. weather. gov/serfc) Prepare – Take Action – Severity & Lead Time – Products &

Hydrology Products WFO Greenville-Spartanburg The End Thank You! We look forward to working with you! Questions, Comments, Feedback? Please contact Joshua Palmer, Service Hydrologist joshua. palmer@noaa. gov 2016 Integrated Warning Team Meeting – Charlotte