Mar 25
Updated 03.25.21 @ 5:45p So far, Indiana has made it through today without little in the way of significant weather. Unfortunately, that won’t be the case through the evening and…
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Permanent link to this article: https://indywx.com/2021/03/25/dinnertime-rambles-dangerous-weather-moves-through-overnight/
Feb 20
Updated 02.20.21 @ 8:29a
Before we dive into the challenges late next week, the potential is still very much alive and kicking for a period of slick conditions to develop Sunday evening/ night. While we’ll likely be in the middle 30s during the majority of the time this light precipitation is falling, the concern remains, given the duration and magnitude of the cold air (ground is now reported frozen “8 to 12”), that any liquid precipitation that falls will freeze on untreated area roadways and sidewalks. If you have travel plans Sunday night, plan to give yourself plenty of extra time.
Light rain should arrive between 8p and 10p (west to east across the state) Sunday before ending as a bit of light snow (little to no accumulation expected as of now). Total precipitation should be 0.20″ or less for most with this event.
As we look ahead, the next item of possible trouble awaits for mid and late week. A cold front will push south of the area Wednesday night into Thursday morning. While this may generate a brief period of light rain transitioning to light snow, it’s what follows that’s of more interest.
Operational guidance (both the European and GFS) suggest this late week system will present a winter storm for our friends in the TN Valley, but we advise to tread with caution for now.
The reason? A strongly negative PNA.
You know the drill by now. This should lead to a more stubborn southeastern ridge and subsequent further north storm track.
Over time, I’d suspect we’ll see just that- the models trending further north with this particular storm system.
As it is, ensemble guidance is already significantly further north than their respective operational counterparts. At the very least, another interesting case study is in front of us…
Stay tuned!
Permanent link to this article: https://indywx.com/2021/02/20/weve-seen-this-before/
Feb 10
Updated 02.10.21 @ 6:23p
Before we look ahead, snow continues to fall across most of central Indiana. So far, immediate downtown Indy has avoided significant snow, but other areas are approaching 1″ to 2″ already as of this post. We continue to believe another band of snow will organize during the overnight into the predawn hours across central Indiana (especially along and north of the I-70 corridor). Given how cold it’s been as of late, even the lightest snow is creating havoc on area roadways. As winds become gusty, blowing and drifting issues will remain into the day Thursday.
As we look ahead, this pattern remains nothing short of remarkable. Feb. 5th (last Friday at 6p) was the last time Indianapolis was above the freezing mark. As we look ahead, we’re likely talking about another 12 days below freezing (if not longer). The “moderation” that some models are hinting at after that time frame isn’t something I’d label as high confidence at this point. That’s rare territory for central Indiana- even during some of the infamous cold winters of the “good ole days.” There’s also already been a fair share of snow events in this pattern. Sure the big one hasn’t hit (yet), but many across the state are getting used to clearing snow off the sidewalk and driveway on a daily basis. Not counting today’s snow, Indianapolis, officially, sits at 2.3″ month-to-date. Areas downstate received as much as half a foot (or more) earlier this week. As we look ahead, there’s a lot more white gold where that came from. (Keep in mind, the “average” snow total during the month of February in Indianapolis is 6.5″).
A fresh intrusion of arctic air will arrive just in time for the weekend. We’re looking at a mostly dry stretch of weather through the weekend, with the exception of some light snow prospects Saturday. Again, given how cold it’s been, even these light snow events will likely create travel trouble.
The coldest morning appears to be Sunday with lows falling to between 3° and 6° below zero. Wind chill values will approach 20° below zero, or worse, in spots.
By this time, all eyes will be on the developing storm system in the northwest Gulf of Mexico. There’s already been a great deal of chatter about this storm and that will only continue to ramp up as we move forward. Given the overall pattern and model consensus at this juncture, there’s plenty reason to believe the Ohio Valley, including central Indiana, is in store for a significant winter storm early next week.
With that said, nothing is a lock in this business. While the negative PNA (image 1 below) argues for the southeast ridge to “flex” it’s muscle and lead to a more inland track, the fact arctic air will be pressing southeast (image 2 below) does at least raise an eyebrow for potential shifts southeast in time over the next couple of days. It’s another fascinating meteorological battle we’ll have the pleasure to watch unfold in real time.
As it sits right now, we favor a storm track that will be far enough west to put central Indiana in play for potentially significant wintry precipitation (far too early to throw numbers out). The early call is for surface low to move out of the northwest Gulf and track west of the mountains before a secondary low take over along the Mid-Atlantic and moves northeast off the New England coast.
If this wasn’t enough, another storm system likely follows later next week that could also produce additional wintry “goods.”
Will every storm produce in your backyard? Negative. That said, when we get to March 1st, central Indiana winter weather fans are likely to look back on February 2021 as a truly special ride.
I suppose time will tell…
Permanent link to this article: https://indywx.com/2021/02/10/reasons-for-and-against-the-big-one-next-week/
Feb 05
Updated 02.05.21 @ 7:18a
Where to begin?! Simply put, the pattern over the next 2 weeks is a winter weather lover’s dream setup. Does that mean central Indiana has to “cash in” on every event? Negative. In fact, by next weekend, we believe the Deep South will even get in on the wintry fun (outside of the higher elevations that have been doing quite well this year). That said, systems will be targeting our general area fast and furious and require us to remain on our toes. Given that a more prolonged period of cold is developing, we should be able to build a nice snowpack for outdoor winter enthusiasts over the next 7-14 days.
The setup is all thanks to a persistent negative to deeply negative AO and the associated high latitude blocking. The Pacific pattern is also changing to allow more meaningful cold (truly arctic air is getting involved in the pattern) into the East with staying power. We can thank the now negative EPO for that. That leads us to the PNA. A negative to even neutral PNA will continue to put resistance on the pattern and result in southern ridging at times. That’s especially true early on in this regime. That puts the Ohio Valley in the cross hairs of these systems. As the arctic air takes hold, I still believe eventually we’ll see a more suppressed storm track for a time but that likely doesn’t develop until late next week. Before that, we have multiple storms to track and a snowpack to build. 🙂
First up is an arctic wave that arrives Saturday evening. This is a system that should deposit 1” to 3” of snow, mainly from Indianapolis and points north (dusting up to 1” across the southern half of the state). This will be a fast moving system that will arrive around 5p across western parts of the state and will be out of here during the predawn hours Sunday.
Temperatures will crash Sunday morning into the single digits and highs will likely only climb into the middle teens. Good thing there’s a Super Bowl to focus on.
Additional upper level energy will result in light snow moving back in here Monday afternoon and night. With cold, arctic air in place, this system should be able to squeeze out an additional dusting to inch of snow (even as weak as it is).
That leads us to Tuesday night and Wednesday. A surface wave is expected to develop in the Ark-la-tex region and lift northeast. This will be a “juicier” event and result in widespread wintry precipitation across the state. Early thinking here is that across central and northern parts of the state, this will be mainly a snow event. Southern portions of the state may mix with sleet and/ or freezing rain. While we can’t throw out numbers this early, where it stays all snow, several inches seem likely.
If that’s not enough, more “fun and games” are dialed up with yet another system next Thursday and Friday. This, too, could be a meaningful winter event, locally, and will require close attention moving forward.
From a temperature perspective, it continues to look like a case of “delayed but not denied” on the topic of truly dangerous arctic air. As the pattern evolves and a snowpack is established, the concern here is that we’re looking at a period of severe cold (double digit below zero temperatures and wind chill values exceeding 20° below zero) by late next week/ next weekend.
More later today! Have a great Friday, friends!
Permanent link to this article: https://indywx.com/2021/02/05/buckle-in/
Nov 22
This morning is once again reminding us that we can deal with wintry “issues” at times even in the midst of an overall mild pattern. As we move down the road, it sure appears as if additional opportunities for wintry weather will present themselves as the pattern evolves towards more of a traditional regime to support such.
More specifically, we’re targeting the period between 11/30 and 12/10. Though still not a “textbook” pattern, the PNA is trending more positive with each run. This favors as eastern trough (example below).
Note how the upper pattern evolves in the coming couple of weeks:
You might be asking yourself, “what would take this pattern to lock-in and become more textbook?” We need the two positives (initially over Saskatchewan and Manitoba to “connect” with the one in the northwestern Atlantic). As it is, we do note the heights continue to build and push towards Greenland. I’m not sure we can pull it off, but the evolution towards a strong PNA can force the issue and eventually lead to a negative AO. Regardless of whether or not we get to that point, which would lead to a more long lasting colder/ stormy regime, I think we’ll have a minimum of 2 opportunities for eastern wintry “fun and games” during the aforementioned period above.
As we get into Week 2 (11/29-12/4), note how the pattern has the look of an active subtropical jet as the “horseshoe” block tries to get established over the top. This is likely still not an overly cold pattern, but one plenty capable of additional wintry fun, even with marginally cold air.
Stay tuned. The closer we get, the more specific we can be regarding the storms. From this distance, if I’m a fan of winter weather, you have to like where you’re sitting as we open up meteorological winter.
Permanent link to this article: https://indywx.com/2020/11/22/troubling-pattern-to-close-november-open-december/
Oct 10
Delta– the remnants of one time powerful Hurricane Delta will curl northeast into the TN Valley today and cross the southern Appalachians Sunday. Central Indiana will miss out on any…
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Permanent link to this article: https://indywx.com/2020/10/10/saturday-morning-rambles-time-to-pull-out-the-heavier-cold-weather-gear/
May 28
Our short-term weather pattern will be dominated by an upper level low (this morning) and a cold front (tomorrow). High pressure will build into the region over the weekend and help supply gorgeous conditions.
The best opportunity for widespread rain over the next week will take place today as the upper low impacts the region. With a tropical airmass in place, this feature will be able to produce a good soaking for most of central Indiana. Widespread moderate rain this morning will continue for the next few hours before being replaced with more scattered activity during the afternoon/ evening.
The next feature we’ll contend with is the cold front itself and it’s still slated for a Friday passage. Scattered showers and storms will remain possible ahead of the boundary but coverage shouldn’t be nearly as widespread as what we’re seeing this morning. Once the front blows through tomorrow afternoon, much drier and cooler air will arrive and stick around for a few days.
Dry conditions will stick around through the weekend and into early next week to result in perfect weather to get some of those outdoor chores knocked out before the warm, muggy stuff returns.
Speaking of that, as we look ahead, we’ll replace the refreshing air with a return of warmth and humidity during the 2nd half of next week. Note how the European ensemble shows the transition.
The JMA Weeklies (fresh in this morning) also show the warmth that looms through the better part of the 1st half of June.
We’ll have to keep close tabs on exactly where the upper level ridge sets up in the Week 2 time period. This will mean the difference between “splash and dash” storm coverage as the mugginess returns vs. more widespread, organized activity in what would be a northwest flow around the periphery of the ridge. Stay tuned.
Permanent link to this article: https://indywx.com/2020/05/28/thursday-morning-rambles-tropical-air-gets-the-boot-eyeing-a-warm-stretch-of-weather-through-the-1st-half-of-june/
May 14
I. After a cold and dry open to May, (Month-to-date, Indianapolis is running 8.4° below avg. and 1.24” below normal in the precipitation department) changes have arrived.
II. A warm front will lift north through the state today and deliver those warmer changes. The transition from cool to more of an early summer feel will be met with a couple rounds of storms today. Some of those storms will be strong to severe (damaging winds being the greatest concern), especially north of the city. Strongest storms should arrive across the northern half of the state during the early to mid afternoon hours.
III. A “half-n-half” weekend is expected. After a wet Friday, drier air is expected to arrive to help us out Saturday. Showers and storms will return Sunday courtesy of a cold front and associated surface low. Locally heavy rainfall will be possible Friday & Sunday and when you add in what falls today, most of the state from the city and points north can expect widespread 2”-2.5” with locally heavier amounts.
IV. An area of low pressure and upper level trough is now shown to “cut off” over the Mid-Atlantic region in the medium range period. This is forecast to dramatically cool the Monday through Thursday time frame (instead of 80s, we’re now talking upper 50s, 60s and low 70s during the period). This is worth keeping an eye on as models can struggle handling these kind of features, but as it stands now, after a brief encounter with warmth this weekend, it doesn’t appear as if we’ll get back to the heat until Memorial Day weekend.
Permanent link to this article: https://indywx.com/2020/05/14/thursday-morning-rambles-storms-accompany-warmth-interesting-twist-to-the-longer-range/
Apr 21
With a little over a week left in April, thoughts continue to focus more and more on May. While our official monthly outlook will come out later next week, we did want to present our early thoughts on the first week of the month.
In short, a rather persistent upper trough is expected to dominate the eastern 1/3 of the country into the 1st week of the month. This should keep things cooler than normal, overall.
This also lines up perfectly with Phase 2 of the MJO in early May. (After a week of disagreement, model data now agrees that the MJO should “flirt” with Phase 3 before cycling back into Phase 2 early May). We note this favors cooler than normal temperatures across our portion of the country.
From a precipitation perspective, there aren’t particularly strong signals for wetter/ drier than average conditions with Phase 2 in May- at least for the Ohio Valley.
The positive PNA, however, can support a bit more of an active storm track through our region and that’s what model data is showing from this distance.
The positive PNA, of course, also supports cooler than normal temperatures across our portion of the country…
Permanent link to this article: https://indywx.com/2020/04/21/early-may-rumblings/
Apr 09
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Permanent link to this article: https://indywx.com/2020/04/09/video-chilly-pattern-settles-in-easter-storm-and-looking-ahead-to-potential-wet-end-to-april/