1. Winter/Spring Outlook: 2018 - 2019
ALBL 78th Annual Meeting
New Orleans
5 December 2018
Jay Grymes
WAFB Chief Meteorologist
LSU AgCenter Climatologist

2. Annual Precipitation Trends: since 1900
USGCRP (2017): NCA4 Climate Science Special Report

3. LOUISIANA STATEWIDE AVERAGE RAINFALL

4. Seasonal Precipitation Trends: since 1900
USGCRP (2017): NCA4 Climate Science Special Report

6. VERY
WET
VERY
WET
VERY
WET
VERY
WET
VERY
DRY

9. U.S. Drought Monitor: 29 November
None
D2 – Severe Drought
D0 – Abnormally Dry
D3 – Extreme Drought
D1 – Moderate Drought
D1 – Exceptional Drought

10. These are “climatological outlooks” … not “weather forecasts”
NWS Climate Prediction Center “Monthly Outlooks”
These are “climatological outlooks” …
not “weather forecasts”
They present the “best scientific guess” for
averages of temperature & precipitation …
… they do NOT provide guidance with respect to extreme weather events.

11. Temperature: December
~40% Above-Normal
33% Near-Normal
~27% Below-Normal
~35% to 45% chance that monthly average temperatures
across Louisiana will be “significantly” above normal

12. Rainfall: December ~50% Above-Normal 33% Near-Normal ~17% Below-Normal
~45% to 55% chance that monthly total rainfall across Louisiana
will be “significantly” above normal

13. “Near-normal” to “Wet”
Temperature:
Jan-Feb-Mar
“EC” – Equal Chances
No Tendency
Rainfall:
Jan-Feb-Mar
“Near-normal” to “Wet”

14. Temperature: Jan-Feb-Mar
“EC” –
No tendencies
No ‘hints’ as to monthly average temperature tendencies
for Louisiana for the period

15. Rainfall: Jan-Feb-Mar
~40% Above-Normal
33% Near-Normal
~27% Below-Normal
~35% to 45% chance that monthly total rainfall across Louisiana
will be “significantly” above normal

16. Rainfall: Jan-Feb-Mar
Locally, a “wet” leaning outlook . . .
. . . but a “dry” leaning outlook for the Ohio Basin
is potentially good news for the Lower Mississippi

17. ENSO – El Niño / Southern Oscillation
-- Ocean-Atmosphere linkage that produces
“shifts” in regional / global weather and
climate patterns teleconnections
El Niño / La Niña: ocean temperature (SST)
‘signature’
Southern Oscillation: atmosphere pressure-
pattern ‘signature’

18. El Niño ‘signature’ along Gulf Coast:
‘Active’ Sub-Tropical Jet - ’Rainmaker’
Sub-Tropical Jet
More Frequent
Gulf Lows
“Warm” SSTs

19. La Niña ’signature’ along Gulf Coast:
‘Less Persistent’ Winter Sub-Tropical Jet
Fewer
Gulf Lows
“Cool” SSTs

20. Pacific Sea-Surface Temps (SSTs) El Niño on the way?
Region of “warm” SSTs
El Niño
on the way?

21. ENSO – El Niño / Southern Oscillation
El Niño – “warm” phase … ~25% of time
La Niña – “cool” phase … ~ 25% of time
La Nada – “near normal”
El Niño
La Niña

22. El Niño Median Rainfall: La Niña Median Rainfall:
November thru March
El Niño in Winter/Spring:
“wet” Gulf Coast
La Niña Median Rainfall:
November thru March
La Niña in Winter/Spring:
“dry” Gulf Coast

23. Average January - April Rainfall El Niño vs. non-El Niño periods

24. Average January - April Rainfall El Niño vs. non-El Niño periods

25. Average January - April Rainfall
Southeast Louisiana

26. ENSO and Bayou State Rainfall
Solid relationships between South Louisiana rain during winter and spring, but weak link for the northern parishes
ENSO can serve as a predictor (“Guidance”) for South LA rainfall for at least part of the year

27. WAFB Chief Meteorologist LSU AgCenter Climatologist (Ret.)
“Thank You!”
Jay Grymes
WAFB Chief Meteorologist
LSU AgCenter Climatologist (Ret.)
225 /

28. This does NOT mean that $LOSSES are declining!
CAREFUL!
This does NOT mean that $LOSSES are declining!