Severe storms possible Saturday as smoke lingers

Smoke Updates

Wildfire smoke continues to impact air quality across the Finger Lakes. There should be some improvement in conditions today, but on and off bouts of smoke will remain possible this weekend, next week, and for as long as the fires over Canada burn. The good news is the area burning is expected to get several rounds of rain in the coming days.

On Wednesday, I mentioned how many of the forecast maps floating around social media were actually single images from a single run of a new, still experimental model. I cautioned that we didn’t know the biases or overall accuracy of that model yet.

Like most forecast models, it did decent at the overall picture but struggled with the fine details.

For example, it showed reduced air quality across the Great Lakes and northeast, going all the way to the very worst, Maroon/Level 6/Hazardous level. That did happen. But, it painted a much larger area experiencing these conditions than was reality… such as here in the Finger Lakes, where we have generally been in the Red/Level 4/Unhealthy level.

Another example is the model consistently showing improving air quality from north to south Thursday night and Friday. That is happening, but it is much slower in reality than the model suggested. Even the most recent runs of the model indicate that, as of 8 am Friday as I write this, we should be back to completely normal air quality. Instead, we remain hovering in that Red/Level 4 zone.

This is why I have a major issue with the tendency of the modern meteorology/amateur weather enthusiast posting raw model data and passing it off to the public as a forecast. Almost every weather graphic which shows “future radar”, every weather app that gives you an hourly forecast for anywhere in the world at the tap of the screen, is model data. It takes trained meteorologists AND a wealth of forecasting experience to interpret these models and then relay accurate, useful information to the public.

The point I am trying to make is to be very cautious with any of these graphics and to never take them completely at face value as the gospel truth for what will actually happen.

So what is this new air quality model show for the weekend?

After the smoke pushes south today and air quality improves at least a little, an incoming weather system tomorrow (more on that below) will turn winds back to the south and bring it back into the area. The smoke may be a bit less concentrated, but air quality will likely still be unhealthy. Sunday is less certain but looks as though the air may be cleaner than the last few days.

Severe Thunderstorm Potential Saturday

Low pressure will pass by the area on Saturday, bringing a chance for severe thunderstorms to the area. As usual, though, there are many factors in play, some that are favorable for storms, and others that could be limiting.

An initial area of rain and thunder is expected Saturday morning as a warm front lifts through the area. There could be a small severe risk with this initial band, especially if it comes in the latter half of the morning. Generally, though, this should not be a major concern.

During the midday and first half of the afternoon, the atmosphere will warm up and destabilize. At least it should. However, if the smoke is thick, it will reduce the temperature some and thus reduce how well the atmosphere recovers from the morning rain. Likewise, if the warm front is slow enough, its clouds and rain may eat into the window available for heating as well.

Even if there are some limits placed on the early afternoon recovery period, there still should be enough to trigger scattered showers and thunderstorms during the mid afternoon and some sort of thunderstorm complex in the late afternoon. This complex will be the one to especially watch as it drops south-southeast across the region. If it becomes well organized, there may be corridors of or even widespread wind damage.

There will also be a tornado threat across the area, both from individual scattered cells ahead of the late day complex, and within the complex itself. The June 18th tornadoes in Rock Stream and Cortland, for example, were from a supercell structure that was embedded within a broader complex of thunderstorms. A similar scenario could play out tomorrow. It does not mean it will for sure, though.

So, to summarize concisely:

• Morning showers and a few storms. Minimal severe threat, but not no severe threat
• Midday and early afternoon primarily dry. Clouds and smoke will partially determine set up for later in the day
• Mid to late afternoon: scattered individual severe thunderstorms
• Late afternoon (5-7 PM?): widespread thunderstorm complex with at least some severe weather but potential for a widespread severe event

Watching Tuesday, Too

The Storm Prediction Center (SPC) has our area outlined for severe thunderstorm potential on Tuesday, July 21 as well. Our area only sees a Day 5 severe classification from the SPC a couple times a year, so it is always noteworthy when the confidence is high enough in a severe weather event of some sort that far in advance.

I will be studying that through the weekend and will have more information Monday morning.

Admin Note

I will be back on my normal posting routine next week, starting Sunday night. This means weather planner posts focused on the next days most evenings Sunday-Thursday and extended looks at the next week or so most weekday mornings. Plus, as always, special updates when the weather turns hazardous (such as tomorrow when I will likely have at least one but probably multiple posts) and severe weather warnings automatically posting to the website.

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