Category: MJO

Wintry Mix Tomorrow Evening; Fresh Long Range Fun…

Friday will dawn dry, but the mid and high level cloud canopy will be a sign of things to come. These clouds will lower and thicken through the day and eventually give way to a wintry mix by evening. While there may initially be a period of snow (especially north of Indianapolis), the majority of the “overrunning” precipitation should fall as a mixture of sleet and freezing rain. In and around Indianapolis and points north, a light “glaze” of ice is possible Friday evening of up to .10″ (after the possibility of a coating of snow).

Dry air will likely have to be overcome at first, but a burst of snow is possible into the city around 5p to 6p before the transition over to the sleet and freezing rain mixture. Eventually, the icy mixture will transition to a cold rain prior to sunrise Saturday.

MUCH colder air will pour into the state Saturday evening with temperatures falling into the 10s prior to midnight Sunday morning and wind chills into the single digits.

As we look longer term, we don’t see any reason to alter our ongoing thoughts of a colder pattern taking hold, overall, over the upcoming 10-14 day period (and likely into the first half of Feb.). We’ve covered our reasoning in previous posts (Phase 7 of the MJO, positive PNA, neutral EPO, etc.). What’s interesting to note is the rather stark difference in the handling of the EPO between the negative GEFS and positive EPS. The likely end result will be somewhere in between; hence our neutral EPO forecast. At the end of the day, it’s really not the EPO, PNA, or NAO that will drive the mean pattern, but the MJO. And with that said, Phase 7 of the MJO features a cold, stormy look.

The high latitude blocking screams for an active storm track across our neck of the woods (as does the slightly positive PNA and neutral EPO). Sure enough, the latest modeling is going towards this stormy look (active southern stream) in the medium to long range period.

A great mentor once taught me to always be leery of ridges over Hudson Bay in the winter time. Time and time again, this pattern setup results in fairly widespread winter storm events through the Lower 48 and we think there is increased potential in this sometime during the Jan. 25-31 time period. While there’s no way to be specific, just keep a mental note in the back of your mind for this threat.

In closing, a review of the latest JMA Weeklies shows a significantly different pattern than what we’ve grown accustomed to as of late taking up residence through the bulk of the upcoming 3-4 weeks. Given the above, it would be tough to argue this look…

Week 1
Week 2
Weeks 3-4

Fresh video update will hit in the AM with new thoughts around tomorrow evening’s winter weather maker.

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First Comes The Cold, Then Come The Storms…

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VIDEO: Friday-Saturday Storm; Leaning On The MJO In The Long Range…

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VIDEO: Short-Term Update And More On Winter’s Return…

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Once A Foe Becomes An Ally: Reasons As To Why Winter Not Only Returns, But Locks-In…

With a full week now in the books, January has opened much warmer than average from the northern Plains into the eastern portion of the country. Widespread anomalies of 10° to 15° above average dominate from the northern Plains into the Southeast.

However, behind the scenes, significant changes are afoot that will likely deliver a drastically different weather pattern into the Lower 48 around and after the 20th. (Next week will begin the colder transition, but it’s not until the 20th and beyond we think the cold has more staying power).

You know we’ve put all of our eggs in the MJO/ EPO basket through at least mid-February. After that point, it’ll be prudent to additionally pay attention to the NAO and AO.

We note the MJO is set to rumble out of the warm phases and towards much colder phases around and after the middle part of the month. The amplitude of this movement suggests a rather rude shock may await…

Phase 5 is, obviously, a blow torch across the East, but things begin to trend colder through Phase 6 and more substantially so by Phase 7.

On the composites above, note the way high latitude blocking gets established and matures during the transition through Phase 6-7.

(There are reasons to believe this amplitude will continue, taking things into Phases 8,1, and 2 as we close January and head into February). Just for fun, here’s what Phase 8 should produce:

A large part of the reason behind thinking winter “locks-in” has to do with what we think will likely be the MJO making a trip through Phases 1,2, and 3 as we open February.

For those interested in the 500mb pattern through those phases (during the month of February), here you go:

It’s not just the MJO that’s set to push winter back into the region, but the EPO, as well. Note the GEFS and EPS in good agreement developing a negative EPO as we push past the middle of January:

One can argue as to the drivers behind what we think will be a colder (and eventually significantly so) shift in the pattern, but a big reason in our minds has to do with the sea surface temperature (SST) configuration. As the winter pattern matures, we think it really was only a matter of time before the analog research (from way back in the summer) began to pay off.

Out of all of the various modeling out there, I think the JMA Weeklies show how things will likely play out best over the next 2-3 weeks. Note the significant changes between this week (image 1) and the Weeks 3-4 (image 2) time period. Cold is set to begin overwhelming the pattern, but with what should still be an active storm track with resistance from the southeast ridge. This would lead to a continued active pattern with the expanding cold.

Fun times ahead. Stay tuned…

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