A cold front will whip through central Indiana Tuesday evening. Showers will accompany the frontal passage, but we still don’t anticipate much in the way of significant moisture across central Indiana. Heavier rainfall totals in excess of 0.50″ will likely fall across drought-stricken areas downstate.
Colder and blustery conditions will be with us Wednesday and Thursday, including wind chills in the upper 20s at times Wednesday morning.
A moderating trend will get underway this weekend as a gusty southwesterly breeze takes hold on the backside of retreating high pressure. This will lead to a couple of days of above normal warmth early next week (not quite done with the 70s just yet).
We’ll continue to monitor for a wet and stormy time of things Monday PM into Tuesday. The severe threat is to be determined and will require fine tuning as we push ahead over the next several days.
Once this area of low pressure and associated cold front blow through, colder air will arrive on gusty northwest winds by the middle to latter portions of next week.
This will set the tone for a rather significant colder shift as we get set to put a bow on the month of October. A secondary and more significant trough will descend into the region just after Day 10. With a developing negative EPO, positive PNA, and MJO heading for Phase 2, it’s time to start “beating the cold drum” a bit harder. In fact, latest 500mb charts would indicate there’s the potential of at least a little wintry mischief present to go along with the colder shift.
This should at least kick up the lake effect snow guns for the first time this season, and we’ll have to monitor things for the possibility of “backside” energy digging south at the base of the trough that would present the possibility of a little early season snow across parts of the Ohio Valley region as Halloween week nears…
Times, they are, indeed, ‘a changing…
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…