No Rest For The Weary; Reviewing The New European Weeklies…

In the short-term, rainfall will increase in overall coverage and intensity as we progress through the overnight and on into Tuesday morning.

Most central Indiana rain gauges can expect to accumulate between 0.50″ and 1.00″ tonight into Tuesday morning. Heavier amounts will be found downstate.

We continue to closely monitor the precise track of vigorous upper level energy that will result in a narrow, but more intense, band of snow Tuesday afternoon into the evening hours. While temperatures will be marginal, it wouldn’t shock us in the least by a wet 1″ to 2″ stripe of snow that’s laid down in a narrow southwest to northeast corridor and this will warrant close attention with subsequent model updates overnight. An early idea of where this may be is below:

Regardless of where this potentially more significant snowband lies, all of us will get in on the “backlash” snow showers/ squall action Tuesday evening and night.

Looking ahead, continued active times loom. We’re tracking additional storms Thursday night into Friday and again over the upcoming weekend. Yet another storm is slated for an arrival early parts of the following week. As cold air continues to get more involved, these storm systems will be plenty capable of dealing out more in the way of wintry “fun and games,” but the pattern is “hectic” right now and each storm will have to be dealt with as they come. Understanding that it’s still in the 6-10 day time period, the storm early next week seems to have the greatest potential of widespread wintry implications of significance. This is given the overall pattern evolution away from the “transitional” period we’re currently in and squarely inside the cold/ wintry window we’ve been outlining from 2/18 through 3/10. Time will tell…

European Weeklies

The new European Weeklies show the cold currently confined to the PAC NW and northern Plains “spreading out” and encompassing a more widespread portion of the country- especially from the Appalachians and points west (but periodically making it as far east as the coast). The cold is forecast by the model to dive deep into the southern Plains and into the Southeast as we move into the latter parts of February into early March. Perhaps the biggest change from tonight’s update from Thursday is the idea that the cold will linger deeper into March than previously thought. (Please note this doesn’t change our current *official* idea of cold lifting by mid-month, but simply just rehashing model output). Let’s see if we can get some consistency to develop before altering our current forecast.

From a teleconnection stand point, the model does take the NAO neutral to negative late Feb into early March before returning things solidly positive by mid-month.

Weekend Threat: Subtle Differences Make All The Difference…

We wanted to take a quick opportunity to discuss the weekend snow threat. While certainly on the table, it’s far from etched in stone. We note the models doing their usual “herky-jerky” moves 5-6 days out. At the end of the day, there’s a notable threat present, but we prefer to watch things unfold over the next few days before beginning to get too excited.

Subtle differences between the European model (image 1) and GFS (image 2) are seen in the handling of the 500mb pattern. The GFS is quicker to phase the upper energy and leads to a more robust system.  The European isn’t nearly as excited and instead dampens the energy coming east.  These seemingly minute differences can make all the difference when it comes to the sensible weather that may (or may not) impact your weekend plans.  If the European is correct, this is a rather non-event, locally.  However, should the GFS idea be correct, this will be a widespread Ohio Valley snow event that’ll require gassing up the snow plows…

The European model weakens the energy coming east needed to fuel a more substantial storm Friday into Saturday.

The GFS model bundles the upper energy and phases things- leading to a more significant wintry threat by Saturday.

Stay tuned as we’re still a few days out from having confidence needed to begin to sound the alarm. 😉

In the longer range, tonight’s data continues to head in the direction where winter will make up for lost time to close January and head on into February.  Delayed, but not denied…

Pre-Christmas Weather Rambles…

I. While we certainly aren’t talking about significant weather events between now and Christmas Day, there will be a couple of impulses of upper level energy that may be just strong enough to produce snow showers and flurries at times.  We’re tracking (2) weak disturbances that stand a chance to get a couple of snow showers going Sunday evening and again Christmas Day.  The one on Christmas, itself, will be a bit stronger and may have a shield of more organized precipitation- likely that would start as wet snow before transitioning to rain before ending.

II. A much stronger storm system will wrap up to our northwest Wednesday night and Thursday.  We’ll notice an increasingly strong southerly breeze during this time period and rain will be on the increase as we progress through the day Thursday.  The trade-off?  Highs between 55° and 60° to close the week- though those temperatures may actually come Thursday evening before cooler air begins to slip in here during the day Friday.

As things stand now, both the GFS and European models, courtesy of Weathermodels.com, aren’t overly excited on rainfall amounts with this storm system, but I think they’ll trend wetter as time goes on.  We’ll continue to forecast amounts between 0.50″ and 1″.

III. All attention is squarely focused on a significant pattern change that takes shape as we head into the new year.  As mentioned in previous posts and discussions, the transition is likely to be a stormy one, but it’s far too early to talk precipitation types.  A combination of ingredients appears to be aligning to create a colder than normal (and potentially significantly so) pattern at the traditionally coldest time of year (mid-Jan).

In the more immediate term, we note the latest GEFS showcases a classic “horse shoe” block that will favor a wintry regime across the east to open the new year- thanks to Tropicaltidbits.com.