Blown Away wrote:LarryWx wrote:Category5Kaiju wrote:Question: given current trends and historic ENSO behavior, could we safely state yet that this will likely end up being a multi-year La Nina?
6 of the last 8 cases back to the late 1800s of strong+ Nino followed by Niña then had a second Niña. However, only 3 of 12 weak to mod Nino’s (and 0 of 7 mod, alone) followed by Niña had a 2nd Niña. Based on RONI, 23-4 Nino was high end mod.
OTOH, 10 of last 14 Niñas (and 5 of last 6) were 2+ years.
Based on that and stats for Niña followed by Nino, I’m going 75% chance of at least a double Niña coming up.
Larry, the timing of the cold neutral into hurricane season and likely moderate Nina into ASO seems to significantly increase the chances for a hurricane for NE Caribbean, SE Bahamas, and SFL. Many of the big storms for these areas occurred under a similar setup and the wildcard are these epic SST’s. Don’t you think there is a likelihood of a big impact in these areas??
The research I did was for CONUS landfalls overall. It showed that on RONI basis, the highest risk vs climo for one’s area ON AVG is especially when ASO is -0.5 to -1.0 with closer to avg risk for one’s area when it is already below -1.0. With RONI likely already down to -0.2 to -0.4 and with Aug still 2.5 months away, the odds favor below -1.0 for ASO or thus close to avg risk for CONUS landfalls overall.
Out of curiosity to see if there was a suggestion of an agreement with this finding, I decided to look at CONUS precip anomalies map for ASO for seasons with ASO RONI -0.5 to -1.0 vs seasons with sub -1.0:
Here’s precip anomalies for ASO RONI -0.5 to -1.0:
https://psl.noaa.gov/cgi-bin/data/uscli ... reate+Plot Notice that the wettest anomalies are concentrated from FL peninsula up the E coast with dry to the west of the wetness stretching from TX to the N and NE
Now, here’s precip anomalies for ASO RONI sub -1.0:
https://psl.noaa.gov/cgi-bin/data/uscli ... reate+Plot Notice that the wettest anomalies go from FL Panhandle westward to SE 1/3 of TX with the dryness further west in W/NW TX N to NB and W into SW US. The FL pen and up E seaboard averages out NN.
So, these maps suggest the tendency for storms to move into the FL pen and/or go up the E coast (i.e., some recurvature tendency near the E coast) for ASO RONI -0.5 to -1.0 vs tendency of further W most active storm track N or NW into Gulf coast with subsequent N movement inland for ASO RONI sub -1.0.
Interesting! This seems to imply the mean steering high is centered further west and/or stronger when La Niña is stronger during ASO. Does this make sense?
RONI:
https://www.cpc.ncep.noaa.gov/data/indi ... .ascii.txt*Edited for modifications