Category Archives: Weather Rambles

Frigid Open To March And Late Month Musings; Reviewing The NEW European Weeklies…

Average temperatures through the 1st (5) days of the month include highs of 46 F and a low of 29 F at Indianapolis. Instead, a frigid pattern will grip the region as we move through early March, including highs that will likely only top out in the lower to middle 20s and lows in the upper single digits to lower 10s as we move through the first week of the month (coldest centered on Sunday through next Wednesday).

Should we get any sort of snow down during the period (still up for debate as of this evening), lows will likely approach 0 F. The best opportunity for accumulating snow over the upcoming week would come Friday night into Saturday, but confidence remains low. Thereafter, we prefer the “suppressed” ideas currently portrayed by modeling as more meaningful winter storm threats impact the lower Ohio/ TN Valley and southern Appalachian region- especially with such an anomalously cold pattern in place.

Speaking of cold, the deep and expansive snowpack across the central and northern Plains won’t allow the late season taste from the arctic to modify as much as it may otherwise. As the frigid air mass settles southeast, below zero wind chill values are a good bet early next week across the northern half of the state. “Tap the breaks” on meteorological winter kicking off March 1st…

With that said, the NAO and AO are expected to remain positive and while initially “trumped” by the significantly negative EPO, this will trend positive by mid-month. These all suggest the cold is limited and that there shouldn’t be any change to the idea that we really begin to feel more spring-like by the middle of March. This is backed up by the continued idea that the MJO rumbles into Phase 4 by mid-March, as well (again argues for warmth).

Sure enough, longer range models show the ridging and associated warmer times ahead:

It should be noted that with the mean trough position taking up shop across the western portion of the country mid-March, not only should we moderate, but we should also see a return of wetter/ stormier times. With the GOM (Gulf of Mexico) running above normal, early season severe weather outbreaks will have to be closely monitored…

The new European Weeklies in this evening also back up the idea of an unseasonably cold 1st half of the month giving way to milder conditions by mid month. The model paints a drier than normal pattern over the Ohio Valley and Mid West over the next couple of weeks before wetter signals return by the middle of March.

No Comments AG Report, AO, Arctic Cold, Client, EPO, Forecast Discussion, Forecast Models, Long Range Discussion, Monthly Outlook, NAO, Plant '19, Rain, Severe Weather, snow, Spring, T-storms, Unseasonably Cool Weather, Unseasonably Warm, Weather Rambles

Disruption In The Force Or Just Noise?

Our longstanding call has been for the period of early to mid-February to feature a “transitional” pattern before locking into one last cold, stormy period for the winter during the 2/18 through 3/10 time frame. The reasoning behind this idea has been stated multiple times in previous updates.

However, there’s no denying that today’s 12z ensemble update (both from the GEFS and EPS) has rattled us a bit with that idea. The GEFS and EPS are in very good agreement at 500mb:

This is in the face of Phases 8 and 1 from an MJO perspective:

Furthermore, the sudden negative “jolt” in the SOI (Southern Oscillation Index) also favors a significant period of cold, stormy weather, locally:

Please understand this isn’t us changing our ongoing forecast that’s out there, but instead making sure we’re presenting a 100% transparent idea from two of the most highly respected ensemble products out there (that have been generating a lot of attention today with this output). We prefer to give it another few days before altering our medium and longer term forecast to see if any sort of consistency can develop.

At the end of the day, this may be a situation where the resistance from the SE ridge puts up enough of a fight to lead to a lack of “suppression” from the hyperactive storm track currently in place, and instead continuing the busy storm track into the TN and Ohio Valley regions as cold air presses.

Rest assured, you’ll be the first to know if a wholesale medium to long range forecast change is required here. Stay tuned.

No Comments Arctic Cold, Client, Forecast Discussion, Forecast Models, Long Range Discussion, SOI Index, Spring, Unseasonably Cool Weather, Unseasonably Warm, Weather Rambles

Accumulating Snow Impacts Central Indiana Saturday…

Light snow is flying across central Indiana this evening, but “light” is the key word here. For most, a dusting is all we’ll muster with this initial wave of energy.

As we move into the first half of the weekend, a more vigorous disturbance will track across the region. We’ll notice snow breaking out across southwest Indiana around lunchtime before the area of snow grows in overall coverage and intensity through the afternoon into the evening hours.

With a cold surface and temperatures in the mid to upper 20s as the snow falls, expect slick roadways across the region Saturday afternoon into the evening. While winds aren’t expected to be particularly strong, the “open country” may experience a few issues with blowing and drifting snow due to the dry, powdery nature.

Most of central Indiana, including Indianapolis, can anticipate 1″ to 2″ of snow with this event Saturday, but there will likely be a couple of 2″+ reports. Snow will diminish from southwest to northeast after midnight.

Attention will then shift to additional snow and severe cold early next week… More on that in the AM.

No Comments Arctic Cold, Blowing/ Drifting, Forecast Discussion, Forecast Models, snow, Unseasonably Cool Weather, Weather Rambles

Looking at the Holiday Week and Ahead to January…

Tomorrow will be a rather uneventful weather day across central Indiana, but things will begin to change as we head into Thursday.

An area of low pressure will track out of the central Plains into the Great Lakes by Friday. The end result will be increasing coverage of showers Thursday afternoon and perhaps even a rumble of thunder Thursday evening.

Most of the concentrated rain should come to an end around dark Thursday. By that time we forecast a general 1/2″ to 1″ to fall in area rain gauges.

More seasonable air will blow in here behind the storm system and we’ll have to keep an eye on energy “attacking” from behind over the weekend. With colder weather in place, snow is possible next weekend.

Looking ahead, a combination of ingredients appears to be coming together to create a rather significant transition in the pattern as we head into January. Note the developing positive PNA…

This will result in more sustained below normal temperatures making a return early January to our neck of the woods…

Additionally, it also appears an active storm track will continue. While impossible to say this far in advance, prospects for above average snowfall (average is 8.6″) appear likely through the month of January.

No Comments 10-day, Arctic Cold, Christmas/ Thanksgiving, Forecast Discussion, Forecast Models, PNA, Rain, snow, Unseasonably Cool Weather, Unseasonably Warm, Weather Rambles

“Pulling The Curtain Back” On The Late December Pattern…

Late December through early January is a critical time period where most folks (even those maybe not normally interested in the weather) are glued in on the forecast.  For some, they’re rooting for a white Christmas, while others are preparing for holiday travel to see loved ones.  The idea here of a transitional pattern remains and this should promote active weather during the holidays this year.

Understanding things can change with respect to timing from this distance (in some cases 2+ weeks out), these are the dates we’re targeting for storm impacts across central Indiana:

  • Dec. 20-21
  • Dec. 24-25
  • Dec. 27
  • Dec. 30-31

Before we talk specifics, it’s important to look at some of the pattern drivers.  Some of these drivers include teleconnections such as the NAO, AO, PNA, and MJO.

Forecast indices with respect to the AO, NAO, and PNA are expected to be more or less neutral through the late month period.  This is what the respective teleconnection “state” would result in the temperature department across the country.

Arctic Oscillation

North Atlantic Oscillation

Pacific North American Pattern

The basis of our late-December forecast is built from the MJO, or Madden-Julian Oscillation.  We note the MJO is expected to rumble through Phase 4 before heading into Phase 5 around Christmas.  Phase 4 (image 2 below) is a warm phase and correlates well to what the week ahead will provide.  However, Phase 5 (image 3 below) is a colder phase and could “up the ante” for the potential of wintry weather around Christmas.

If the MJO amplitude remains, it’ll roll into Phase 6 to close the month and open January.  Here’s how that would correlate in the temperature department:

The upcoming week will run milder than normal- lining up perfectly with MJO Phase 4.

The first of our targeted holiday storm systems will come at the tail end of the warm Phase 4 and will likely deliver a wind-whipped rain in here as early as Wednesday night and Thursday morning.  However, as the storm pulls northeast along the Ohio River, it’ll deepen on its journey into the eastern Great Lakes region.  This will help pull colder air into the region, likely resulting in rain transitioning to snow Friday.  Given the path of the storm, this doesn’t favor some sort of prolonged backlash snow event, but it could be enough to result in accumulating snow across eastern Ohio Valley sections and downwind of the snow belt regions of northern IN, OH, and MI.

The pattern, as a whole, appears to be one of transition to close the month and open January and it’s not really until we get to mid-January where we think all of the drivers “align” to create more of a lock and hold cold pattern.  With that said, a stormy late December pattern can present problems, even in the midst of relatively mild times.  We’ll be here to dissect the storms as they come throughout the holiday season…

No Comments AG Report, AO, Christmas/ Thanksgiving, Forecast Discussion, Forecast Models, GFS, Lake Effect Snow, Long Range Discussion, MJO, NAO, PNA, Rain, snow, Unseasonably Cool Weather, Unseasonably Warm, Weather Classroom, Weather Rambles, Windy