I interput it as leading the vortex to being disrupted having to move off the pole. I may be wrong and can be corrected but didnt we have something similar latter half December and its 3 to 4 week lag is whats causing the lobe we are tracking trying to get up under the block. Im Probably way off
There are various strat diagnostics to look at, but for our weather, the biggest thing we are looking for is the lower strat (100mb) to be in a weakened state. Simon Lee's research states that -NAO is 7 times more likely when the lower strat is in a weakened state. But yes, that weakened state favors more potential for blocking and cold air outbreaks. An SSW that occurs higher in the stratosphere (10mb) and downwells into the lower stratosphere is one way to get the lower stratosphere in a weakened state, but it's not the only way. Sometimes things align where the lower strat is weak without an SSW (e.g. winters of 2010-2011 and 1995-1996).
Thanks!Although there is a split in the contours here, an actual hardcore split would be when the entire Strat PV splits into completely separate 'daughter' low anomalies. So, this is showing an SPV that is stretched and pushed off the NPole a bit, which is how a SSW Displacement would be. But either way, the SPV is highly disturbed right now. The NASA GEOS MERRA forecast shows the lower stratosphere dropping to record / near record lows in mid-Jan (100mb)
This image is from the 06z GFS run. This covers the full stratosphere and troposphere (1mb down to 1000mb). The blue coloring shows how the zonal winds are weaker than normal thru the stratosphere with some downwelling occurring in the forecast. Source: http://weatheriscool.com/
You can get some good Strat images for free here with the NASA GMAO GEOS forecasts. Note that images can be slow to load when you click on them on that site (i.e. Animate button), but otherwise the loops work well once loaded. Source: https://fluid.nccs.nasa.gov/wxmaps//
Yeah, I think the going theme is that we already have a weakened SPV thru the full strat. An SSW occurring in mid-Jan would only accentuate the condition - it wouldn't need to downwell quickly because the weakness is already there in the lower strat. Attempts of model diagnostics showing the SPV increasing in strength have failed recently. Strengthening could come down the line, but probably not in the foresesable future.
No.
Phase 8 w/El Nino coming to a theater near you in early-mid Feb with renewed blocking. Are yall ready for this??
Ignore how the line stops and curls around in Phase 6. No reason to think this won't just continue on. Phase 6 here 20 days from now (Jan 26). Then 10 or so more days to Phase 8
Am I reading this right that we don’t necessarily want phases 1 and 2 the further we go into January?
Ok thanks. The MJO is something that I’ve really tried to learn more about the last couple years, and I always thought that we needed a lot of help in other areas when it’s not in 8,1,2 so this is good to know. From the looks of this, even 4,5, and 6 look good during February ninos.
@Chazwin the way I interpret this is phase 4 is the 2nd worst phase you can be in Jan. with a 3.8 percent chance. That flips to one of the more favorable in Feb. But that 1st chart looks like that's all ENSO states combined. When you break it down by Enso phase 4 is still the 2nd worse in an El Nino. But that's not broken down by month and includes DJFM so I'm not sure if that changes toward mid Jan. Either way the favorable period being talked about from the 15th through 20th is almost surely going to be a strong phase 4. So it seems chances are certainly not zero, but they are greatly reduced. Maybe the blocking works wonders and we beat the odds. Who knows?
I’m personally not convinced that we ever go high amp. The RMM charts have really not been very accurate this year on the progression of the MJO. Even still as we get later in the month, we move closer to where 4-6 definitely improves. Also, something I’ve noticed is at times this winter, the models have really been wanting to pump the SER like what the CMC showed last night, but as we get closer in, it becomes more muted. I clearly think this is due to the influence of the active Nino STJ which keeps the SER muted.
