Dec 20
A scan over multiple computer models this morning shows that forecast models remain consistent of the idea of a weekend deluge across central Indiana. Unfortunately, when combined with the snow melt, if even the numbers are half right, we’ll have to deal with significant flooding this weekend, especially Saturday afternoon through Sunday.
Here’s a look at the data. We average multiple computer models together to come up with our precipitation forecasts (both rain and snow) that you see in our daily 7-Day Video Forecasts (available to the right of this post).
Needless to say, when looking over all of the data above, we still feel confident in the forecast we have out…widespread 3-4″ rainfall with locally heavier totals. Preparations should have already begun if you live, or work, in a flood prone area, but if not, please do so today. The question remains not if we’ll see flooding, but how severe the flooding will be.
Permanent link to this article: https://indywx.com/2013/12/20/model-data-not-backing-down-on-flooding-rains-ahead/
Dec 19
As always, your latest 7-Day Video Forecast can be found to the right in the video player. 1.) A milder southerly air flow allowed us to remain above freezing…
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Permanent link to this article: https://indywx.com/2013/12/19/thursday-morning-weather-rambles/
Dec 18
Mother Nature seems determined to put us weather forecasters to hard work as we get set to head into the Christmas season and welcome in 2014. We’re tracking a major flood situation that will unfold across central Indiana over the upcoming weekend, followed by a reload of the cold and potentially a storm with a more wintry component as we get closer to the New Year.
First things first and that’s the significant flood threat in the short-term period. Without trying to go into scare tactic mode, current model data would result in a downright dangerous flooding event for many low lying and flood prone areas this weekend. Rainfall numbers are extremely impressive with this event and with a deep tropical connection, widespread 3-4″ totals are certainly likely, including some localized higher amounts. Note the latest European chart, courtesy of the model suite off Weatherbell Analytics. Needless to say, the Gulf of Mexico is officially “open for business” and will help contribute to excessive rainfall totals and, as stated above, potentially a dangerous flooding event this weekend across central Indiana.
Latest numbers averaged off a variety of computer models would place just under 4″ of rainfall down by noon Sunday, most of which falls between Friday and Sunday morning. We note (2) waves of enhanced rainfall intensity set to impact the region. As of now we’re targeting Saturday afternoon and again late Saturday night/ Sunday morning for extremely heavy rain, shown below.
We still have time to watch the data and monitor the track of the storm. It’s possible the “heaviest of the heavy” axis of rain shifts somewhat in the days ahead, but it’s also important to note that even a light to moderate rain event combined with a frozen ground and a solid snow pack still in place will lead to flooding problems here across central Indiana. The question of whether or not we’ll deal with flooding here this weekend shouldn’t be asked, but instead the question that remains is just how severe will the flooding be? Stay tuned and if you live or work in a flood prone area, we would recommend preparing now for flooding.
Now, as we look ahead and focus on the Christmas to New Years period our thoughts will shift from a flood threat in the near term to one that’s more wintry. We’ll turn dramatically colder Sunday afternoon behind the big rain storm and that will set the stage for a colder-than-average run up to Christmas. In fact, latest raw numbers off some forecast model guidance has some frigid readings ahead next week (upper single digits not ruled out for lows).
The upcoming 10 days off the European forecast model charts show an interesting scenario with the coming thaw, but the key word is brief. Note days 6-10 are back into a colder-than-normal regime.
Additionally, we think we’ll have to deal with another storm prior to the New Year period and with the colder air back in place, there’s the threat we could have to contend with a wintry side to the next storm. The details with storm number two will have to wait until we finish dealing with the first storm and associated serious flood threat it’s presenting.
Permanent link to this article: https://indywx.com/2013/12/18/a-lot-of-weather-to-talk-about/
Dec 18
Your latest 7-Day video forecast can be found in the video player to the right of this post.
We’ve known for over a week now that we’ll have to deal with a pre-Christmas storm. Latest guidance suggests our region undergoes a 3-4 day thaw with a decidedly warmer southwest flow ahead of this storm. Additionally, with the more northern track of the surface low, we’re looking at nearly all of the precipitation associated with this storm falling as rain. Combine our frozen ground with a significant early-season snow pack and multiple inches of rain ahead in the Thursday night through Sunday time period and the stage is set for a significant flood situation this weekend.
Here’s a look at what the latest forecast models show. We’ve posted the GFS, Canadian, and European models below to display total rainfall between Thursday through Sunday. The majority of this rain falls in two waves- Friday and again late Saturday into early Sunday.
If the rainfall numbers are even half of what is projected above, we’re looking at a significant flood situation. Needless to say, if your property is in a low-lying area, or one that is prone to flooding, I would begin to prepare now for major water rise in the days to come.
Much more later!
Permanent link to this article: https://indywx.com/2013/12/18/significant-flood-situation-ahead/
Dec 16
During the late summer and early autumn months we were trying to look at the big picture and potential drivers in the overall weather pattern for the upcoming winter and openly admitted the challenges that were ahead. Here we are now into the second half of December and a much colder and snowier-than-average month is a virtual lock at this point. Furthermore, consider this has all taken place without the presence of a favorable NAO or PNA. Sometimes you have to look for other drivers in a pattern- in this case, the EPO, as well as a growing early fall snow pack across the border to our north. Additionally, we made mention of the likelihood of a southeast US ridge periodically making itself known through the winter of ’13-’14. You can read all of our thoughts posted earlier this fall here, or by clicking the Thoughts On Winter ’13-’14 page above.
As we look ahead towards the upcoming wintry challenge, we’re confident of the overall pattern, but the sensible weather that’ll ensue is still up for great debate. “Gut” tells me central Indiana will be looking at a rain to freezing rain scenario, but this is far from set in stone, and sometimes forecasters who go simply off their instinct can get burned. The pattern is one that (once again) will feature a pressing arctic front against resistance from the southeast US ridge. With this type of scenario, I would advise against looking at each and every individual operational model run, but instead invest time studying the ensembles- an average of several multiple model runs as opposed to just one operational model run. I can guarantee a variety of wild solutions ahead in the days to come, based off the operational runs. (Heck, just the past 24 hours have been reason enough to have the dramamine on hand :-)). That said, let’s take a look at the latest GFS and European ensembles, two models that we rely heavily on in the mid range weather pattern.
First, the GFS, valid Saturday through Monday.
Now, here’s a look at the latest European ensembles (left), again valid Saturday-Monday.
So what do all of these cool maps tell us? Simply put, that “wintry mischief” is brewing for the weekend. That much we know, but the details have to be ironed out. It’s likely heavy snow and a significant ice storm looms for some of the Mid West and Ohio Valley for the upcoming weekend. Is that Indianapolis or Chicago? Perhaps in between? It’s too early to know. Additionally, in the “warmer” sector, heavy rains are likely to combine with an impressive early season snow pack for some to lead to flooding concerns.
A couple of additional items to note. Many times at this stage in the game (still 5+ days out) with this type of pattern, forecast models really struggle with handling low level cold air. Cold air is very dense and, in this type of set up, can easily drain much further east and south than forecast at this juncture. Additionally, sometimes the modeling can put too much “umph” into the associated surface wave that moves along the arctic front resulting in a further north track than what may actually occur when the event draws closer. Just something to keep an eye on as we draw closer…
Needless to say, it’ll be particularly important to keep a close eye on the developing weekend forecast as we move forward. It’s likely folks in the Ohio Valley region have to deal with significant precipitation amounts in the Saturday-Monday time period, including rain, freezing rain, and snow.
Permanent link to this article: https://indywx.com/2013/12/16/major-storm-brewing-this-weekend-but-details-are-murky/
Dec 16
Good Morning, Hoosiers! We’re awaking to a snowy commute, as promised, but our little clipper could certainly be called an “over-achiever.” We’re receiving many reports of snowfall amounts of 1.5″…
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Permanent link to this article: https://indywx.com/2013/12/16/have-to-love-over-achieving-clippers/
Dec 15
Following on the heels of another early winter weather maker, we’re tracking renewed cold blowing into the region and two light snow producers the next couple of days. The first clipper system will likely deliver some light snow accumulations (generally 1″, or less) tonight into the wee morning hours Monday. The latest short-term, high-resolution, model data is picking up on this nicely. While we’re not looking at significant snowfall, it’ll be just enough to lead to a slick Monday morning commute for some, especially from the city and northern ‘burbs.
Here’s a look at the simulated radar valid for this evening at 10 o’clock. Light snow is spreading back into central Indiana.
Additionally, we’ll keep an eye on yet another fast-moving clipper Monday night and early Tuesday that will also have the potential of dropping a quick light accumulating snow (again, most likely 1″ or less). All-in-all, we’re still locking tightly into Old Man Winter’s grip the next few days.
Permanent link to this article: https://indywx.com/2013/12/15/tracking-two-light-snow-producers/
Dec 14
Latest short-term, high resolution, models are showing what’s taking shape nicely this morning. We think the city and points north will undergo a period of moderate to heavy snow from late morning into the early afternoon hours.
Within the highlighted area, we think snowfall rates will approach 1″ per hour between 10a-2p. Yes, within that (4) hour time period, don’t be surprised if a few reports come in with 3-4 additional inches of snow atop what’s already fallen, particularly across the northern half of the highlighted area.
Here’s a look at the latest HRRR model simulated radar showing the swath of moderate to heavy snow coming over the next few hours. Again, high snowfall rates will make plowing duties difficult so if you must travel, please take things slow.
South-central Indiana will see dramatically less snow due to mixing issues (as forecast) and the dry slot that is arriving now. The track of the upper low should lock moderate to heavy snow into central and north-central Indiana into the early to mid afternoon. All of the snow will then begin to diminish and move northeast during the early to mid afternoon, as our storm system departs. This will then allow northwest winds to strengthen and become gusty this evening, with cold air pouring back into the region.
Permanent link to this article: https://indywx.com/2013/12/14/period-of-heavy-snow-coming/
Dec 13
As a whole, we still feel good about our accumulation ideas that we’ve had out a few days now…widespread 4-5″ of snow is a good bet for most of central…
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Permanent link to this article: https://indywx.com/2013/12/13/friday-night-saturday-winter-storm/
Dec 12
Before we discuss what may lie ahead closer to Christmas, our going forecast for Friday night and Saturday’s snow storm hasn’t change…4-5″ for the greater Indianapolis region by late Saturday morning.
Since really back in the middle of October we noted a distinct pattern change that has resulted in a colder than normal regime around these parts ever since. As we look ahead, there really aren’t any indicators that would suggest we’ll deal with warmer than normal air for any period of significant time through the remainder of the year. Furthermore, there are multiple computer models hinting that we’ll have to deal with a significant winter storm and potentially a shot of brutal cold as we rumble closer to the busy Christmas week.
It’s very important to note that we still have several days to watch the goings on for Christmas week, but the stage has at least been set for the possibility of a storm of “importance” being around the region as we near that particular time period.
Confidence is growing on brutal cold (most likely record-breaking) initially dumping into the Plains states towards the latter portion of next week. With time, we think this cold slugs it’s way east. Before the arctic intrusion gains control of the Mid West and Ohio Valley, we think this is the area that stands the greatest chance of dealing with a major winter storm. We have strong ensemble support (pictured below) of the evolution of the overall pattern, but we caution that the precise details will have to be ironed out.
The “sensible” weather that would ensue here across central Indiana could vary wildly from a significant full-blown winter storm with all of the precipitation falling in the form of a wintry variety (i.e. snow, sleet, freezing rain) to a situation that features a western track with briefly milder air surging north into portions of the region and leading to a rain-to-snow situation. The accumulation ideas would swing from a significant, plowable, snow storm to as little as a coating with arctic air blowing in behind the rain to snow scenario.
At the end of the day right now we’re confident on two things: 1.) a major winter storm around the Mid West/ Ohio Valley as we near Christmas week and 2.) brutal arctic air swinging into the area around Christmas. Questions will have to be answered as we move ahead to determine the precise precipitation amounts and type.
In closing, just for fun, we thought we’d provide a look at the latest European forecast model data. Here’s a look at the upcoming 10 day European model snowfall forecast. Of course, these amounts account for the 4-5″ expected here tomorrow night and Saturday, but (2) additional systems also add to the potential growing snow pack…a clipper system Monday and the “more important” system next weekend. Stay tuned.
Permanent link to this article: https://indywx.com/2013/12/12/old-man-winter-jabbing-now-but-is-the-knock-out-punch-coming/
