Mar 09
Good Sunday afternoon! We’re enjoying beautiful weather and conditions will only improve Monday into Tuesday. That said, a potential winter storm looms Wednesday. Additionally, we’re keeping a close eye on…
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Permanent link to this article: https://indywx.com/sunday-afternoon-update-awesome-stretch-of-weather-before-dramatic-changes/
Mar 05
We continue to closely monitor the goings on towards the middle of the month- more specifically March 12th through the 14th. There are indications a significant late season winter storm is brewing and the overall pattern is one that is aligning itself in a way that certainly has to raise an eye brow. That said, it’s far too early for precise details. Is a major storm possible? Absolutely. Is it okay to pin down a given area for heavy snow totals at this stage? Absolutely not.
First, let’s take a look at the latest ensemble charts.
GFS
European
Canadian
At this stage in the game (more than a week away from the expected event), we suggest investing much more in the ensembles as opposed to a single operational model run. (Case in point just from today alone…the 0z run of the European suggested the interior northeast was ground zero for widespread 12″ type snowfall totals with little to nothing expected across central Indiana. Flip ahead 12 hours later and the 12z European takes the heavy snow axis through the heart of central Indiana on into the Northeast region).
Wikipedia has a nice write up on ensemble forecasting:
Ensemble forecasting is a numerical prediction method that is used to attempt to generate a representative sample of the possible future states of a dynamical system. Ensemble forecasting is a form of Monte Carlo analysis: multiple numerical predictions are conducted using slightly different initial conditions that are all plausible given the past and current set of observations, or measurements. Sometimes the ensemble of forecasts may use different forecast models for different members, or different formulations of a forecast model. The multiple simulations are conducted to account for the two usual sources of uncertainty in forecast models: (1) the errors introduced by the use of imperfect initial conditions, amplified by thechaotic nature of the evolution equations of the dynamical system, which is often referred to as sensitive dependence on the initial conditions; and (2) errors introduced because of imperfections in the model formulation, such as the approximate mathematical methods to solve the equations. Ideally, the verified future dynamical system state should fall within the predicted ensemble spread, and the amount of spread should be related to the uncertainty (error) of the forecast.
Though this is an event set to take shape close to a week from now, confidence on a significant storm across the east is higher than normal due to:
1.) Excellent agreement amongst the three primary mid range ensemble charts.
2.) The significance of the trough depicted on each set of ensembles.
While there are some differences, it’s highly unusual to see such relative agreement at this stage in the game. We continue to bracket March 12th through the 14th time period for potential impacts from this storm across central Indiana. Many questions will remain unanswered for now concerning precipitation type or amount, but we’re leaning more towards a winter weather maker at this early juncture for the Ohio Valley region. We stress this can, and likely will, change multiple times in the days ahead.
Regardless, we strongly agree with the week 2 temperature anomalies courtesy of the GFS. Should this come to fruition then March 12th through the 18th would feel more like early February then early to mid March. Again, we think the GFS is on to something with the return of the cold pattern.
As we move ahead know that we’ll be here keeping a close eye on the goings on behind the scenes around the potential “trouble” brewing for mid month. As we continue to dig into the details with this potential storm, you worry about finding ways to enjoy the spring like feel Friday and again Monday :-). We forecast both days to certainly have many craving spring as temperatures zoom well into the 50s both days. Get out there and enjoy it!
Permanent link to this article: https://indywx.com/trouble-brewing-mid-month/
Mar 03
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5/ 32 |
17/ 36 |
20/ 39 |
24/ 52 |
29/ 39 |
20/ 38 |
29/ 53 |
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Light |
Light |
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Light |
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Forecast Updated 03.04.14 @ 8:22a
Sunny, But Cold…Another day of bright sunshine will help temperatures rebound to the freezing mark Tuesday afternoon. While this is still well below normal and closer to the normal low for this date of 29 degrees, it’ll be a full 14 degrees “milder” than Monday’s high. You know it’s been a cold winter when you’re saying the freezing mark is milder for a high in March.
Weak Weather Maker…A weak clipper system will move towards the region Wednesday evening into Thursday. While this will be an accumulating snow producer for areas to our west, current thinking still moves this moisture towards our region, but with a dry air mass in place we think precipitation starts to fall apart as it moves in. All of that said, light snow and scattered snow showers will fall for parts of the region Wednesday night into early Thursday. We still think most don’t deal with much, if any, accumulation, but a light coating is possible in spots. We’ll continue to monitor.
Eyeing Another Wintry Weekend…Modeling is still far from in agreement on the evolution of things on the weekend, but the general idea is one that brings a cold front through here Friday night into early Saturday morning with a wave of low pressure moving northeast out of the middle Mississippi River Valley into the eastern Ohio Valley Saturday. With fresh cold air oozing south, combined with the associated track of the low, this is a potentially wintry set up for the region and we’re officially calling for a wintry mixture of light snow and/ or sleet across central Indiana Saturday. The key word is light, but it could still be enough to create a few slick spots across the region.
Briefly Milder; Tracking The Next Significant Storm…The GFS and Canadian forecast models keep our region dry during the early to middle part of next week as a surface low tracks out of the Gulf and well south and east of our region. On the other hand, the European forecast model winds a storm up much farther north and west and presents a heavy rain and possible thunderstorm threat here by Tuesday and Wednesday of next week. We still have time to watch this and think the European may be a little too aggressive at present, but stay tuned.
What we are confident on is a briefly milder push of air early next week that could send temperatures well into the 50s. Don’t get used to it, however, as yet another polar plunge arrives by the mid week stretch.
Upcoming 7-Day Precipitation Forecast
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Permanent link to this article: https://indywx.com/a-record-cold-start-possible/
Feb 28
As we’ve been discussing, a significant winter storm is developing this weekend. The set up is one that will feature an arctic cold front sinking south and stalling out across southern and central Indiana Saturday night. Low pressure will then organize over the Ark-la-tex region and head northeast, tracking into the northern Tennessee Valley Sunday and Sunday night. The low will move off the southern Mid Atlantic coastline Monday evening. This will be more of a prolonged event when compared to our last two winter storms as waves of moderate to heavy snow move into central Indiana beginning late Saturday night.
This is an ominous set up for more heavy snow across central Indiana- one that’s notorious for heavy snow events across central Indiana. We hoisted our initial snowfall forecast Thursday morning and placed central Indiana under the threat for 6-8″. As of this morning, we’re remaining firm on that idea. It should be noted that the GFS remains very bullish on heavier totals (and consistent, as well), but it should also be pointed out it’s somewhat of an outlier as of this morning as the GEM and ECMWF are more suppressed with lighter totals. All of that said, we lean more towards the GFS solution versus the more suppressed Canadian and, to some extent, European forecast model. Should the other model data begin to trend towards the snowfall idea per the GFS then the initial 6-8″ forecast will have to be adjusted upward. The storm is just now coming onshore and will be sampled better with model runs later today.
Any way you slice it, a significant and disruptive winter storm is brewing this weekend and could make an absolute mess of your Sunday and Monday. A shot of bitterly cold air will flow in behind our departing storm early next week.
Our current accumulation idea and storm track can be found below: We’ll have another update here late tonight and you can keep up-to-date with all of our thoughts on the go on Twitter (@indywx).
Permanent link to this article: https://indywx.com/more-on-this-weekends-winter-storm/
Feb 16
1.) A scan over the latest data continues to point towards an absolute mess of a Monday afternoon. Our accumulation ideas remain relatively unchanged from this morning’s update, aside from “beefing” expected snow totals for Indy’s northern ‘burbs by 1″. Most of this falls from noon to 6pm and will be followed by a dry, cold, and blustery Monday night. After likely a white-nuckle evening commute Monday, the combination of sub-freezing temperatures and gusty northwest winds Monday night will likely lead to another rough commute for Tuesday morning.
** We caution that this will be another “now cast” situation when it comes to precipitation types and their respected precise zones tomorrow afternoon. Stay tuned here or to your favorite local weather media for updates and potential changes.**
2.) We continue to monitor what will be a brief thaw and associated flood risk mid week. Even without rain, water rise would occur and urban flooding from the combination of melting snow and blocked (from all of the snow) drainage zones. When you add 0.50-1″ of rain atop the melting then problems could arise Wednesday into Thursday. Additionally, we’ll need to prepare for the likelihood of dense fog Wednesday as milder air surges north over a deep snow pack.
3.) For anyone thinking spring is setting in during our mid week thaw will need to think again. Latest model data continues to suggest we reverse things quickly later this week and for the upcoming weekend. In fact, some model data, including the European, suggests central Indiana is under the gun for a weekend winter storm. We’ll continue to monitor closely…
4.) Additionally, prospects continue to grow for another extended period of well below normal cold and renewed wintry precipitation chances in the long term (into March). Both the GFS and European models are in agreement on the mid to long range pattern with a trough settling back into the eastern half of the country.
Permanent link to this article: https://indywx.com/sunday-afternoon-thoughts/
