Jay Grymes Jay Grymes WAFB Chief Meteorologist WAFB Chief Meteorologist LSU AgCenter Climatologist LSU AgCenter Climatologist Flooding in the Amite Basin: Flooding in the Amite Basin: I I ncreased Threat in the Coming Months? ncreased Threat in the Coming Months? Strengthening El Niño?
Jay Grymes WAFB Chief Meteorologist LSU AgCenter Climatologist
Jan 15, 2016
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?. - PowerPoint PPT Presentation
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Jay GrymesJay GrymesWAFB Chief MeteorologistWAFB Chief Meteorologist
LSU AgCenter ClimatologistLSU AgCenter Climatologist
Flooding in the Amite Basin:Flooding in the Amite Basin: IIncreased Threat in the Coming Months?ncreased Threat in the Coming Months?
Strengthening El Niño?
Flooding in the Amite Basin:Flooding in the Amite Basin: IIncreased Threat in the Coming Months?ncreased Threat in the Coming Months?
-- reviewed daily mean stage for -- reviewed daily mean stage for ‘Amite nr Denham Springs’‘Amite nr Denham Springs’for the period Oct 1974 – present . . .for the period Oct 1974 – present . . .
data courtesy of USGS, Louisianadata courtesy of USGS, Louisiana
-- “flood events” defined as at least one day with -- “flood events” defined as at least one day with daily mean stage ≥ 29.0 ftdaily mean stage ≥ 29.0 ft
-- “moderate flood” defined as at least one day with-- “moderate flood” defined as at least one day withdaily mean stage ≥ 35.0 ftdaily mean stage ≥ 35.0 ft
-- “major flood” defined as -- “major flood” defined as instantaneousinstantaneous stage ≥ 39.0 ft stage ≥ 39.0 ft
Nov-to-Mar Rainfall: Departure from NormalEl Nino Winter/Springs: 1950 - 1995
Rainfall Below Normal Rainfall Above Normal
El Niño El Niño ‘Signature’ along the G‘Signature’ along the Gulf Coast: ulf Coast: ‘‘Active’ Active’ Sub-Tropical JetSub-Tropical Jet
El Niño El Niño ‘Signature’ along the G‘Signature’ along the Gulf Coast: ulf Coast: ‘‘Active’ Active’ Sub-Tropical JetSub-Tropical Jet
Sub-Tropical Jet
““Warm” SSTsWarm” SSTs
More FrequentMore FrequentGulf LowsGulf Lows
El Niño
La Niña
La Nada“Neutral”
December-thru-May Rainfall:Louisiana EC Climate Division
1974-75 thru 2009-10
6-mo. Rainfall (in.)
Rainfall Data: NOAA/National Climatic Data CenterENSO Ranks: NOAA/NWS Climate Prediction Center
El N
iño/
Sout
hern
Osc
illati
on(E
NSO
) Ran
king
Series Median
Seasonal rainfallSeasonal rainfalltends to be greatertends to be greater
during El Niño eventsduring El Niño events
Amite River near Denham SpringsFlood Events: Oct 1974 – Present
by Month
‘Juan’(1985)
‘Allison’(2001)
‘Babe’(1977)
‘Gustav’(2008)
51 Events
River Stage Data: USGS, Louisiana
-- 4 as ‘tropical’-- 3 in summer/fall
Amite River near Denham SpringsFlood Events: Oct 1974 – Present
by Month
19901990
‘Major’ Floods: > 39 ft
1983198319771977
Apr 1977 & Apr 1983Apr 1977 & Apr 1983 . . . ‘major’ floods . . . . . . ‘major’ floods . . .
both during El Niñosboth during El Niños
51 Events
River Stage Data: USGS, Louisiana
Amite River near Denham SpringsFlood Events by Year: 1974 – Present
(All Months)
River Stage Data: USGS, Louisiana
Amite River near Denham SpringsFlood Events by Year: 1974 – Present
(December thru May)
River Stage Data: USGS, Louisiana‘Major’ Floods:
> 39 ft
El NiñoEl Niño
La NiñaLa Niña
ONI Index: NWS Climate Prediction Center
NWS/CPC ENSO ONI Index:Jan-Feb-Mar Index Score
35 Seasons: 9 El Niños & 9 La Niñas
NWS/CPC ENSO ONI Index:Jan-Feb-Mar Index Score
& Occurrences of Winter/Spring Floods
El NiñoEl Niño
La NiñaLa Niña
ONI Index: NWS Climate Prediction Center
11
55
22
22
11
33
11
1100
11
0000
22
1111
00 00
00
El Niños:El Niños:16 floods16 floods
in 9 in 9 seasonsseasons
La Niñas:La Niñas:5 floods5 floods
in 9 in 9 seasonsseasons
La Nadas:La Nadas: 23 floods in 17 seasons23 floods in 17 seasons
No ‘moderate’ to ‘major’ floodsNo ‘moderate’ to ‘major’ floods
ClimaticClimaticRegimeRegime
RatioRatioFloods : SeasonsFloods : Seasons
El NiñoEl Niño 1.8 : 11.8 : 1
La NadaLa Nada 1.4 : 11.4 : 1
La NiñaLa Niña 0.6 : 10.6 : 1
TropicalTropical 0.1 : 10.1 : 1
Flooding in the Amite Basin:Flooding in the Amite Basin: IIncreased Threat in the Coming Months?ncreased Threat in the Coming Months?
ClimaticClimaticRegimeRegime
RatioRatioFloods : SeasonsFloods : Seasons
El NiñoEl Niño 1.8 : 11.8 : 1
La NadaLa Nada 1.4 : 11.4 : 1
La NiñaLa Niña 0.6 : 10.6 : 1
TropicalTropical 0.1 : 10.1 : 1
While flooding in the coming months is not a certainty, climatic signalsWhile flooding in the coming months is not a certainty, climatic signals(El Niño) point to an elevated threat of ‘high water’ along the Amite(El Niño) point to an elevated threat of ‘high water’ along the Amitenear Denham Springs . . . and therefore much of the greater Amite Basin.near Denham Springs . . . and therefore much of the greater Amite Basin.
Related Documents
