1 / 13

Jay Grymes WAFB Chief Meteorologist LSU AgCenter Climatologist

Flooding in the Amite Basin: I ncreased Threat in the Coming Months?. Jay Grymes WAFB Chief Meteorologist LSU AgCenter Climatologist. Strengthening El Niño?. Flooding in the Amite Basin: I ncreased Threat in the Coming Months?.

keziah
Download Presentation

Jay Grymes WAFB Chief Meteorologist LSU AgCenter Climatologist

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Flooding in the Amite Basin: Increased Threat in the Coming Months? Jay Grymes WAFB Chief Meteorologist LSU AgCenter Climatologist Strengthening El Niño?

  2. Flooding in the Amite Basin: Increased Threat in the Coming Months? -- reviewed daily mean stage for ‘Amite nr Denham Springs’ for the period Oct 1974 – present . . . data courtesy of USGS, Louisiana -- “flood events” defined as at least one day with daily mean stage ≥ 29.0 ft -- “moderate flood” defined as at least one day with daily mean stage ≥ 35.0 ft -- “major flood” defined as instantaneous stage ≥ 39.0 ft

  3. Nov-to-Mar Rainfall: Departure from Normal El Nino Winter/Springs: 1950 - 1995 Rainfall Below Normal Rainfall Above Normal

  4. El Niño ‘Signature’ along the Gulf Coast: ‘Active’ Sub-Tropical Jet Sub-Tropical Jet More Frequent Gulf Lows “Warm” SSTs

  5. December-thru-May Rainfall: Louisiana EC Climate Division 1974-75 thru 2009-10 El Niño La Nada “Neutral” El Niño/Southern Oscillation (ENSO) Ranking La Niña Series Median 6-mo. Rainfall (in.) Seasonal rainfall tends to be greater during El Niño events Rainfall Data: NOAA/National Climatic Data Center ENSO Ranks: NOAA/NWS Climate Prediction Center

  6. Amite River near Denham Springs Flood Events: Oct 1974 – Present by Month 51 Events -- 4 as ‘tropical’ -- 3 in summer/fall ‘Babe’ (1977) ‘Juan’ (1985) ‘Allison’ (2001) ‘Gustav’ (2008) River Stage Data: USGS, Louisiana

  7. Amite River near Denham Springs Flood Events: Oct 1974 – Present by Month 51 Events Apr 1977 & Apr 1983 . . . ‘major’ floods . . . both during El Niños 1983 1977 1990 ‘Major’ Floods: > 39 ft River Stage Data: USGS, Louisiana

  8. Amite River near Denham Springs Flood Events by Year: 1974 – Present (All Months) River Stage Data: USGS, Louisiana

  9. Amite River near Denham Springs Flood Events by Year: 1974 – Present (December thru May) ‘Major’ Floods: > 39 ft River Stage Data: USGS, Louisiana

  10. NWS/CPC ENSO ONI Index: Jan-Feb-Mar Index Score 35 Seasons: 9 El Niños & 9 La Niñas El Niño La Niña ONI Index: NWS Climate Prediction Center

  11. NWS/CPC ENSO ONI Index: Jan-Feb-Mar Index Score & Occurrences of Winter/Spring Floods 5 El Niños: 16 floods in 9 seasons 1 El Niño 1 2 3 1 1 0 2 La Niñas: 5 floods in 9 seasons 0 1 1 0 0 1 0 0 2 La Niña No ‘moderate’ to ‘major’ floods La Nadas: 23 floods in 17 seasons ONI Index: NWS Climate Prediction Center

  12. Flooding in the Amite Basin: Increased Threat in the Coming Months? While flooding in the coming months is not a certainty, climatic signals (El Niño) point to an elevated threat of ‘high water’ along the Amite near Denham Springs . . . and therefore much of the greater Amite Basin.

More Related