Category: Forecast Models

Tuesday Morning Rambles: Opportunity For Cross Polar Flow Late Month And Looking Ahead To A Renewed Active Pattern…

Updated 02.06.24 @ 5:27a

We’re pushing 6 days now since our last measurable precipitation and that unusually calm, boring stretch of weather will continue for a couple more days. Despite some low clouds at times, expect our quiet and unseasonably mild weather pattern to continue. A late week frontal passage (FROPA) will pull a true taste of spring north into the Ohio Valley and lower Great Lakes Thursday into Friday. We still don’t anticipate this being a significant precipitation maker for central Indiana.

A secondary (much stronger) low pressure system will ride along this pressing boundary and impact areas to our east (and south) with heavier precipitation over the weekend into early next week. The southern Appalachians once again may “cash in” on a hefty snow event.

This more active period comes as a wholesale pattern change gets underway with a significantly colder air mass aimed to overwhelm much of the Lower 48 as we push into next week.


We note longer range models showing cross polar flow setting up late February. To no surprise, the ante is upped for the threat of a period of significant cold prior to month’s end.

We’ll watch for the threat of new winter weather opportunities to emerge during this colder pattern down the road.

Permanent link to this article: https://indywx.com/2024/02/06/tuesday-morning-rambles-opportunity-for-cross-polar-flow-late-month-and-looking-ahead-to-a-renewed-active-pattern/

VIDEO: Potential Of Significant Period Of Cold; #Plant24 Pattern Thoughts…

Updated 02.05.24 @ 6p Potential is on the increase for a period of notable cold during late-February. We look into this along with the staying power, and early thoughts on…

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VIDEO: Enjoy A Quiet And Mild Week Ahead Of A Significant Pattern Change…

Updated 02.05.24 @ 7:30a This week will be about as quiet and mild as it gets around these parts for early-February. Enjoy, friends. A weak frontal boundary will slip through…

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Permanent link to this article: https://indywx.com/2024/02/05/video-enjoy-a-quiet-and-mild-week-ahead-of-a-significant-pattern-change/

We Know The Cold Is Set To Return, But What About The Precipitation Pattern Mid-Feb Into Mid-March?

Updated 02.04.24 @ 11:11a

The coming pattern change back to cold has been long advertised and fits the overall theme of El Nino winters. The question now centers squarely on not “if” the cold is going to return, but just “how” cold will it get? Should we spend time in Phase 8 then the door opens for another opportunity to rival the magnitude of cold we saw in January. The strongly negative AO and NAO argues for pronounced high latitude blocking to develop yet again, and likely with more staying power than our January blocking episode.

500mb pattern Feb. 10 – Mar. 10

But enough about the return of below normal temperatures. What is the longer range guidance suggesting as far as the overall precipitation pattern goes? During the pattern “transition state” (late week into Week 2), we favor a more active precipitation pattern as at least (2) more organized storm systems should roll through the Ohio Valley. Specifically, we’re targeting a system 2/8 into 2/9 followed by a more organized and heavier precipitation maker in the 2/11 -2/13 timeframe.

Beyond mid-month, the majority of extended, long range forecast models highlight a drier than normal pattern returning to the picture. This is forecast to continue into the 1st half of March. A more active (wet) pattern is forecast for the Southeast. Not shocking, especially given the anticipated colder than normal regime.

This doesn’t mean snowfall will run below average, but it’s also impossible to get specific with winter storm potential more than a week out. While we’ll keep an eye on next weekend, the threat of winter weather potential will increase through the 2nd half of the month and into the 1st half of March with the colder pattern returning. The latest ensemble guidance is bullish on a snow pattern emerging during that time period.

Perhaps we’re gearing up for a busy 2nd half of the season?

Permanent link to this article: https://indywx.com/2024/02/04/we-know-the-cold-is-set-to-return-but-what-about-the-precipitation-pattern-mid-feb-into-mid-march/

Mild Week Ahead; More Prolonged Cold Pattern On The Table?

Updated 02.04.24 @ 8:55a

An unseasonably mild and quiet week is on tap. We aren’t forecasting rain to return into the picture until late week and the upcoming Super Bowl weekend. Highs will likely flirt with, if not exceed, the 60° mark Friday ahead of a frontal passage.

An unseasonably mild week is on tap.
Highs will flirt with, if not surpass, the 60° mark Friday.

After Friday’s FROPA, we’ll watch the trailing, more significant piece of energy impact the Ohio Valley next weekend. Obviously, it’s far too early to determine if we’re talking about more rain and/ or snow, but the initial hunch here is that this should be primarily a liquid event, despite the snowy solution on the overnight European model. We’ll watch carefully in the coming days.

The more active pattern late week and over the weekend is a signal that the pattern is changing. Once again, we believe that we’re heading into more of a prolonged version of what we dealt with in January, thought the jury is still out on the extreme solutions on the table with respect to just how cold (should we get into Phase 8 of the MJO then look out). As it is, the teleconnection suite aligning in a manner that they are is reason enough to be fired up on an all-out return of winter for mid-February. The forecasted strongly negative NAO (North Atlantic Oscillation) provides us with a greater than normal confidence level that this cold pattern will have staying power not only through the remainder of the month, but into the 1st half of March (at least).

Latest long range modeling highlights the prolonged nature of the cold pattern:

Temperature anomalies Feb. 17 – Mar. 20

Make it a great Sunday, friends!

Permanent link to this article: https://indywx.com/2024/02/04/mild-week-ahead-more-prolonged-cold-pattern-on-the-table/

VIDEO: All Is Quiet (For Now); Initial Spring And Summer Ideas As We Head To La Nina…

Updated 02.03.24 @ 10:12a The calm weather pattern that we’ll enjoy this weekend is giving us time to look ahead to a significant pattern transition to La Nina and the…

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Permanent link to this article: https://indywx.com/2024/02/03/video-all-is-quiet-for-now-initial-spring-and-summer-ideas-as-we-head-to-la-nina/

Friday Morning Notes On The Pattern Ahead…

Updated 02.02.24 @ 7:37a

We don’t see any reason to deviate from the longstanding ideas on the overall pattern evolution ahead. February will continue to provide an unseasonably mild and quiet stretch through the first 1/3 of the month ahead of a pattern transition back to colder around or just after 2/10.

2/2 – 2/8

2/9 – 2/16

Note the ridge begins to break down across the East during the Week 2 period above. This is the transition to colder times, locally, as heights begin to build across western Canada and the northeastern Pacific. By mid-month, we’re talking about an entirely different pattern as a trough continues to deepen across the East along with unseasonably cold air become more entrenched.

In the shorter term period, not only are we talking about unseasonably warm temperatures (it’ll push 60°+ here late next week) but also incredibly quiet weather. In fact, we aren’t looking at another opportunity for measurable precipitation until next Thursday.

A warm front and trailing cold front will return a round of unsettled weather (rain and even thunderstorm potential) here as we get set to close the work week next week. More on expected rain coverage and amounts as we get into the weekend and next week.

Permanent link to this article: https://indywx.com/2024/02/02/friday-morning-notes-on-the-pattern-ahead/

Welcome To February…

Updated 02.01.24 @ 7:45a Aside from a dry back door cold front overnight, all is quiet in the weather world, locally, but changes are on the horizon around the 10th…

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Unseasonably Dry And Calm Open To February; Winter’s Return…

Updated 01.31.24 @7:06a

In the short term, there’s really nothing of significance to discuss. We have no changes to our thinking that February opens on an unusually dry and mild note. In fact, we don’t forecast our next opportunity of measurable precipitation until late next week or next weekend.

Upcoming 10-day precipitation anomalies
Upcoming 10-day temperature anomalies

Despite the well earned thaw that we’ll enjoy now, winter is far from over. In fact, not only do we forecast a return to a cold, wintry pattern around Feb 10th (give or take a day or two), but it’s easy to build a case that this should be a more prolonged cold blast when compared to its January predecessor. The reason? Alignment with the teleconnection suite (emphasizing the anticipated strong negative NAO). We also anticipate the MJO getting into Phase 8 by mid-month which opens up the window for the potential of more extreme cold.

To no surprise, the latest ensemble data is pointing towards where the pattern is heading once past the first 1/3 of February.

Once we lock into the colder pattern, thinking here is we’ll remain locked in with an overall cold signal to close Feb and open March (first 10-14 days). It may be a “rubber band” type pattern. Cold to open before an abrupt flip to significantly warmer (hot?) conditions for the second half of March.

Permanent link to this article: https://indywx.com/2024/01/31/unseasonably-dry-and-calm-open-to-february-winters-return/

VIDEO: Weak Clipper Today; Unusually Quiet Stretch Of Weather Ahead…

Updated 01.30.24 @ 7:16a A weak clipper will deliver mixed showers this morning and a round of light snow showers this evening. Totals with both rounds of precipitation will be…

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