Old man winter is asleep on the Southeast but he’s not dead yet.
We have more rain and more unseasonably warm weather ahead in the coming week (temps 18-26 degrees above-normal) as the cold front that brought the severe weather Saturday stalls out and then drifts back North as a warm front through Tuesday before another cold front moves through on Thursday that will bring back noticeably cooler weather to end the week 50s and 30s and the downward trend will continue next week.
It will turn colder in the medium to long-range period and we may have to monitor another strong thunderstorm chance somewhere along the way in the transition, after a marginal risk of a strong thunderstorm Tuesday afternoon or night.
5-DAY RAINFALL TOTAL ESTIMATE:
1-2 inch rain totals are expected by the time the week ends on AVERAGE, with isolated 4 inch totals possible for localized flooding.
500MB JET STREAM FLOW PATTERN TUESDAY:
An arctic air mass is seen in Southwest Canada while a broad mild Southwest to Northeast jet stream flow is seen for much of the U.S. below I-80 including an active sub-tropical jet flow across the Southland.
However, there is mounting predictive data supportive of a change to a pattern that will support periods of colder weather back to normal highs and lows for dead winter or even some spells of below-normal roughly January 19 into early February with some milder spells in-between but not nearly as warm as recently.
But given poor model performance for many months I will not jump on any long-lasting frigid air yet.
None-the-less the “Modoki El Nino” atmospheric behavior continues and the MJO is forecast into more favorable phases and there is consensus among the various numerical variants for a pattern flip with +PNA West Coast ridging in the jet stream pattern and a -EPO which can deliver colder air and is the opposite of the upper-air flow pattern we have now seen in map above.
The +IOD in the Indian Ocean area and the MJO in the West Pacific have kept the U.S. pattern mild to this point, but changes are afoot as seen in the WxBell Charts:
Weather has cycles and they typically last on the order of 45 days or so sometimes 60 before changing, we are getting close to that from the last chillier jet stream pattern in the U.S that occurred in November and early December after the warm autumn so that fits.
Likewise current data suggest stratospheric warming over the North Pole another signal of pattern change and the warm sea-surface “blob” persists beneath Alaska in the NE Pacific.
The analogs continue to be supportive of a flip in the pattern since there is precedent in past warm winters to end noticeably colder, as recently as 2015 for example.
That has been a common theme of many winters in the 2000s with February and March and I think we’ll do it again as the SE upper ridge gets beaten back down and squashed out of here with the change starting next weekend and increasing in the weeks beyond.
So January 17-27 is a transition period it probably won’t happen overnight but it looks like the pattern will flip and last in on and off fashion into March.
Any snow or ice threat unlikely through Jan 21 but final 11 days of this month OR next month can’t be ruled out. Confidence highest I-40 or a little South but I-20 or South not off the table.
I am just saying winter is far from over, it’s just too early to cancel it.
But keep in mind I am not predicting anything because specifics that far out in time are not scientifically valid so I don’t do that.
IF if and when there is something stronger to say I will.
I try to be right not first to mention snow or ice, this is not supposed to be a game of look at me.
I don’t get extra pay for blogs or tweets or Facebook so I don’t seek attention or likes, retweets, shares or forwards. Nothing in it for me. I also consider unscientific long-range hype to be unethical and unprofessional.
But data is mounting that at the very least we are going to change to at a minimum more neutral conditions in the key teleconnections to one that allows at least the possibility of something to occur in that time frame, maybe maybe January 24th give or take a few days but odds are highest I-40 North not I-20 but nobody can be sure this far out.
So let me reiterate it’s not a forecast for any snow or ice because that can NOT be known this far in advance by anybody or any gadget.
KEY TELECONNECTION LOCATIONS:
I am simply saying a “window of opportunity” as I like to call them may be opening as we end January and continuing at times next month and first half of March.
I do not yet see any EXTREME cold however so far, nor do I see weeks of non-ending cold.
The global numerical prediction models projected pattern flip MJO and GFS ENSEMBLE 500MB JET STREAM:
For more follow me on Twitter @MellishMeterWSB.