We note the modeling continues to want to keep the North Atlantic Oscillation (NAO) negative into late month. As mentioned in previous discussions, the NAO is “king” late winter and spring.
It should be no surprise that the GEFS 5-day temperature anomaly shows widespread below normal air centered on March 22nd.
This doesn’t mean brief surges of warmth, originating in the southern Plains, can’t shoot into the Ohio Valley for a couple of days. Perhaps we’ll “luck out” and enjoy a briefly milder time for St. Patrick’s Day. This does, however, mean that overall we have a long, long way to go before “stick and hold” spring can arrive, locally, and the balance of the upcoming 2-3 weeks looks colder than average.
Side note: The upcoming couple weeks looks drier than average for our region, while the TN Valley into the Carolinas remains abnormally wet. Our friends in the southern Plains continue to deal with dry times and the drought will only worsen in coming weeks there…
The first few days of March have gotten off to a warmer than average start, but the coming 5-10 days will run colder than average across a large portion of our region.
Perhaps of more importance, and a greater focus, locally, is the potential one of these storms will slow down and intensify into something more significant than a 12-24 hour period of snow showers and squalls. The first contender arrives over the upcoming weekend, but with this being 4-5 days out, confidence remains low.
However, it’s important to understand model biases from this distance. So often, the GFS can rush things along in the medium range, only to later correct as time draws closer. If things slow, the associated energy will merge and result in the possibility of a significant, if not major, late-winter storm for portions of the Ohio Valley. As it is, a few of the GEFS ensemble members show this potential.
Unfortunately, there’s no way to be more specific from this distance. It’s easy to see both arguments (for and against a more significant storm) from this point, but with high latitude blocking in place (an ingredient missing most of the time from this winter, and several of the past few winters), we most certainly need to keep close tabs on subsequent model runs. Long-time Hoosiers remember when storms of significance actually did, indeed, impact the area. 🙂
II. The next item we continue to monitor has to do with an initial piece of energy that will scoot across the Ohio Valley Friday. This is ahead of a more significant storm that will likely develop over the weekend and models continue to fluctuate on how they handle things. For now, we’ll maintain a rain/ snow mix Friday, but simply can’t get more specific than that. There are ways this could deposit a stripe of accumulating wet snow for some of the region, but it’s premature to try and nail down where this may occur.
III. We also have to continue to keep a close eye on what transpires Sunday. We favor one surface low tracking along the Ohio River into the Appalachians before a secondary low takes over along the Mid Atlantic coastline Monday. Again, a swath of wet snow north of the low’s track Sunday into early Monday.
IV. While we should see warmth eject out of the southern Plains in the Week 2 time frame, the large majority of data says this will only be temporary and that cooler than normal temperatures will persist through the balance of the upcoming several weeks. With late season high latitude blocking in place it’s hard to disagree with that idea. Once blocking sets up (especially late in the season), it can be like “pulling teeth” to get any sort of sustained warmth. Just an idea here.
Model data continues to show this idea has merit and now we’ll have to handle the individual storms as they come. As we’d expect late in the winter, challenges abound, but this is a pattern that has potential. Can we turn potential into reality? That’s the question that will be answered over the next couple weeks.
The next item on the agenda will arrive Friday afternoon into Friday night. It, too, should spread snow across a portion of the Ohio Valley. With this being in the Day 6 time period, expect fine tuning as we move through the upcoming week.
Finally, a third system will impact the area about this time next week, and it’s this system that appears to be the most significant of the group. Far too early to get detailed, but it certainly warrants our attention.
The overall pattern we’ll “enjoy” over the next couple of weeks is one that’s been lacking for the better part of the past few winters. With blocking in place, storm systems trying to lift into the Great Lakes will be “forced” south and result in an active time of things around these parts- including the east coast, as well, over the better part of the upcoming 10-15 days.
Our next storm system will arrive Monday. Clouds will increase overnight and showers (mostly light) will arrive on the scene during the day. Rainfall amounts aren’t expected to be significant this go around (in general, 0.25″ to 0.40″ for most). Winds will turn strong and gusty during the day Monday, continuing Tuesday and Wednesday.
Colder air will get pulled into the Ohio Valley Tuesday evening and as upper level energy moves overhead, mixed rain and snow showers will develop Tuesday night through Thursday morning.
By next Thursday morning, widespread lows in the 20s can be expected.
The early spring “fling” has lulled many into believing winter’s finished. While the worst of the winter is certainly behind us, we continue to think a dose of “reality” awaits as we progress through the better part of the first half of March. To be more specific, we feel the period March 6th through the 20th will offer up below average temperatures and an active pattern- capable of producing wintry threats.
Sure enough, modeling is going to the pattern that will produce below normal temperatures (doesn’t appear to be anything particularly frigid, but colder than average, nonetheless) through mid-month.
With blocking in place, an undercutting jet will serve to deliver an active storm track.
Keeping in mind March winter events need multiple items to come together to create impactful situations, it’s also important not to simply “buy in” to the idea that just because it’s been warm lately that winter is finished. March can be a wild month, as long-time Hoosiers are aware. The pattern we’re heading into over the next 10-14 days is one that’s been void most of the winter (high latitude blocking in place) and can serve as the player needed to flip a “nuisance” variety late-winter event to one that’s much more significant. We’ll need to remain on guard for the potential of one or two “more significant” wintry events as we move through the first couple weeks of the month.
The end result is one that should promote colder than average times over the next couple weeks, overall, along with an active storm track. With blocking in place, the potential of one or two more significant late-winter events are on the table, and we’ll have to fine tune specifics as the individual storms come. While confidence is high that someone within the Ohio Valley region is likely to still deal with a big-hitter event, there’s no way to get specific until the individual players are on the field. Thereafter, the pattern should begin to transition to one more conducive for “stick and hold” spring conditions during the latter portion of the month.