Updated - See Below
It's Friday! Time to get the weekend thoughts in motion.
I wish I had a day like yesterday to bring by you for the forecast this weekend, but it's a little murkier than that-- starting with today. You can follow the temperatures in the tracking tools below, but suffice it to say this is another one of those days where some of us will be moving as much as 40-degrees from the morning low to the afternoon high. Here's what's on our plate:
|HPC - Friday 2pm||HPC - Friday 8pm||HPC - Saturday 2am
As we've talked about before a "Low Pressure System" typically has a Warm front out ahead of it, and a cold front dragging behind it. This stands to reason because the air circulation around a low pressure center in the Northern Hemisphere rotates counter-clockwise. This puts winds out of the south (warming) on the eastern side, and the back end has the colder winds wrapping around from the north. Both fronts are capable of generating precipitation. The cold front, however, is often the generation point of your thunderstorms, because it marks the digging of colder air into a situation that has already been well warmed. Colder air is more dense than warm air, which allows it to slide under and lift up as it approaches, offering an easy trigger for showers and storms. The models are picking up the two separate incidents of rain opportunities well. Here, for example, is the GFS:
|GFS - 2pm Friday
||GFS - 2am Saturday
So it's not so much the initial 'warm front' showers we're going to be concerned about, but instead the showers and storms associated with the cold front as it scrapes through. As we discussed the other day, often it's where the front is during the prime heating time of the afternoon that becomes the best opportunity for storm formation (like we saw on Wednesday). The Storm Prediction Center is also looking at this combination of events when it paints a sliver of our area into the "slight risk" category for severe weather.
We'll have to keep an eye on this for our entire area too, but the cold front (the triggering mechanism) doesn't get to most of our area until sunset or later, so the opportunity to strike during max heating will be past. Some of the dynamics aren't as strong with this event, but some isolated strong/severe storms could still stumble into our zones. You'll get the full suite of tracking tools today :-)
The weekend looks "okay" at this point, with a break coming in starting Saturday around lunch and continuing into lunchtime Sunday as well, though we may not be able to make it through the entire weekend completely dry. But still, you'll have several consecutive hours of salvageable weather for outdoor plans. Don't forget, we're still tracking a larger storm system ahead for next week, but we'll talk about that again soon enough...For now, your tracking tools :-)
Update 10:30am - The Storm Prediction Center has part of our area under a "Slight Risk" for severe weather, with a rather impressive impulse expected to fire up this mid-afternoon (again, prime-time heating-wise) in Indiana and Illinois. Here's the breakdown of what's expected with these storms...
|SPC - Hail Threat||SPC - Wind Threat||SPC - Tornado Threat|
The idea here is that there will be strong/severe storms on the maps this afternoon, and we can track them across areas north of the Ohio River, but they will weaken somewhat as they make their approach to our area (the dynamics are weaker when the sun is removed from the equation). So, there should be a good amount of action this afternoon, but just outside our area. The folks that have the greatest potential to be affected by these strong/severe storms later this evening/overnight will be those in interior sections of Ohio. Check the tracking tools for updated SPC products and storm reports, and of course we have the radars and warning maps updated continuously.
Update 4:45pm - The line of storms that will have our attention into the night has started to form in Illinois, Indiana, and western Ohio. It will take a while for it to get into our area, so we can see what kind of a punch it packs when as it approaches. Western and northern sections of our area stand the highest risk of encountering a strong/severe storm, because these will be weakening as we lose sunlight.
|Regional Radar/Satellite with Warnings Tracking||
From the Storm Prediction Center (below): Click For a Larger Image
|Activity Overview||Storm Outlook||Watches||Potential Watches||Storm Reports|
|Temperatures||HD Doppler Radar||Estimated Rainfall||Active Warnings|
|Click For Larger||Click For Interactive Radar||Click For Larger||Click For Larger|
Have a great day everyone!