The photo above comes from NOAA Satellite imagery. (ZOOM.EARTH is a great place to see updated satellite images, make sure you check them out!) It shows the two systems that will impact the Great Lakes Region today and tomorrow. Read on to find out more!
This was a post that originally was going to go up yesterday, but the latter of the two systems continues to evolve more, so I figured a day wait would be good. Of course, this did delay the 2nd Paris post, but that will actually go up tomorrow morning at 8 AM followed by an update regarding tomorrow’s system. (Go read Post One about Paris in the meantime…if you haven’t already. And I know if you did or didn’t!)
We have two systems that will be impacting the Great Lakes Region today. The first is a rather rare occurrence as Tropical Depression Cristobal continues to inch northward. The second is a negative tilt shortwave along with a surface cold front that moves through the area tomorrow (more typical for this time of the year). These two systems combined could cause some issues over the next 24 to 36 hours.
Cristobal Remnants (Tropical Depression/Post-Tropical Depression) – We’re going to focus on Cristobal first, as it is the one that will be affecting us in the near-term. First, what is now Cristobal, began as an area of disturbance in the Bay of Campeche, named Tropical Depression Two-E. This was back on May 31st. That same day, the storm became Tropical Storm Amanda and then made landfall in Guatemala. It’s remnants ended up moving north and northwest as this second area of disturbance was back in the Bay of Campeche. At this time, it became Tropical Depression Three and then eventually became Tropical Storm Cristobal on June 1st (the earliest third named storm in Atlantic Hurricane history…on the official start date of Hurricane Season). The storm then made landfall near Atasta, Mexico where it really began to weaken (usually noticed by a decrease in thunderstorm activity near the center). The storm really began to lose its structure, clipped Guatemala, then moved northward quicker than anticipated, allowing it to strenghten quicker over the open waters of the Gulf. As it moved away from the Yucatan however, it began to lose a lot of its central structure. With dry-air interaction and an upper-level trough, Cristobal was taking on the appearance of a subtropical cyclone (much of like we do get in the Midwest) with most of the convection being east and north of the circulation. Even with it’s structure not being like that of a Tropical Cyclone, it still remained a Tropical Storm with sustained winds in the category. At 5:10 PM on June 7th, Tropical Storm Cristobal made landfall near Grand Isle, Louisiana.
Since then, Cristobal has continued to churn northward, but the approaching cold front will push it slightly eastward later. The National Hurricane Center has just issued their final advisory on Cristobal, whose center of circulation is over Northern Missouri. This means that later this evening, Tropical Depression Cristobal will no longer be a tropical system and will become subtropical/post-tropical depression. What this means for the Midwest/Great Lakes states won’t necessarily change the effects of the storm, but it does bring about something very interesting. While tropical systems sometimes to make it to the Great Lakes region, it is rather uncommon. We in the Great Lakes will be getting a Tropical Depression this afternoon into the evening. Just think of how weird that sounds for a second.
Much like any tropical system, the rainfall is a big issue. The center part of the system will move over parts of Iowa, Minnesota, Wisconsin and then the Upper Peninsula of Michigan before exiting into Canada. The rainfall, as well as associated winds, will be big here (and, actually, its possible that Cristobal could become a Post-Tropical Storm before it exits the United States). Also, much like any tropical system, the front right quadrant (Northeast) of the center of circulation is where the biggest risk for intense storms could be. As Cristobal continues to move north, it is dragging up a very humid tropical air mass into areas of the Midwest (with a warm front). Temps in the high 80s and low 90s are expected throughout many of the Great Lakes States today, even for those locations along the lakeshore where the lake usually helps keep you cool….not happening today! This will accompany high dew points, leading to a really humid situation…much like you would find in the tropics. Heavy rain bands of Cristobal are lagging to the south of the circulation a bit, around portions of Western Kentucky & Tennessee. It is ahead of these rain bands that we have to watch for any more rain bands to develop.
Any of the associated bands in the front-right quadrant has a chance of producing severe weather. As this is a tropical system, the threats with the storms will be damaging winds and tornadoes. Tornadoes that develop in these systems are usually extremely quick and are short lived, making them even a bit more dangerous because warnings usually come as they are occurring, so keeping an eye on the situation is the best form of protection. You may notice on the SPC forecast that there is an area of Enhanced Risk over parts of Kansas & Nebraska. This doesn’t have anything to do with Cristobal, instead, it is part of the system we have moving in tomorrow.
Back to the Great Lakes region, almost all of Illinois as well as Indiana and Southwest Michigan have the highest likelihood of seeing severe weather today. Even so, it isn’t a slam dunk because Tropical Systems are Tropical Systems….but when severe weather does form, it forms in a hurry. What we will have to worry about is, as the arcing bands continue to push/rotate through, low-level shear as well as the backed surface winds, which lie ahead of the approaching cold front, does spell a tornado concern. Once again, these would be brief spin-ups and not your long-lived monsters for the most part. In addition, a 65 knot low level jet is expected to develop overhead in parts of Western Michigan/Northern Indiana, leading to an increase in risk for damaging winds in any convection. Hail will NOT be a threat for today’s storms. The largest threat will be for Indiana and Illinois for this, but Southwestern Michigan needs to keep an eye on it. There will be a lag between the conditions (CAPE arrives much earlier than the helicity), but there will still be a few hours of favorable enough conditions for severe weather, and any storms that form within bands in Northern Indiana could definitely maintain themselves as they move North/Northwestward.
Coastal Counties in West Michigan as well as counties in Wisconsin should watch for high winds that will run along the developing low-level jet on the east side of Cristobal. In Michigan, these winds will also end up being enhanced by convective activity.
As with any system in the past, have a way to get warnings. Keep an eye on the weather, watch your local news station and check out your local NWS office at www.weather.gov for warning updates. Some radar apps, such as MyRadar, will also notify you if a watch or warning is issued for your area.
I will point out the primary uncertainty faced in the region of risk today…will there be enough surface heating within the richer moisture plumes from Cristobal. That’s what will lead to higher severe weather chances. With the increasing threat means higher probabilities for wind or tornadoes. All still remains to be seen. Make sure you check out the NWS office graphics included below…note that these are ever-evolving too!
The Second System – Shortwave/Cold Front: Not going to focus on this system too much today because we have to get through the first punch still. But I will briefly discuss it just so we know what may be coming. This system has evolved a bit over the past few days. Yesterday, the system was expected to be in the extreme eastern portions of the Great Lakes region by afternoon time. The timing on the system has slowed down a bit and may slow even more.
The shortwave and cold front will not clear the area now until later in the day, giving ample time for prime conditions to develop. Not a slam dunk again, but just something to be aware about. Destabilization could lead to surface based CAPE (Convective Available Potential Energy) approaching 2000 j/kg along with surface dew points in the 70s ahead of the cold front. Couple this with deep layer shear values above 50 knots, and we have all severe modes in play…damaging winds, large hail, and tornadoes. The highest threat will be areas east of US-131 in Michigan as well as Eastern Indiana, much of Ohio and parts of New York State. That all also depends on how much the system slows down. That’s why I don’t want to get too much into the system today. Things can always change. But for now, it is a system to keep an eye on because it could get dicey tomorrow too. I have included the SPC Outlook for tomorrow below (remember, this will change and evolve)
As models continue to evolve, I may update below with some images from model runs on PivotalWeather. This goes for both Cristobal as well as tomorrow’s system. In the meantime, make sure you follow me on Twitter at www.twitter.com/universeofadv for the latest updates with the weather. I’ll also be re-tweeting watches and warnings so everyone is aware (as much as I can, at least). Don’t forget to follow on Facebook and subscribe by entering your email on the right. You’ll always get notified when new content drops! No spam, just content!
Remember, have a way to receive warnings. That is the most important thing for today and tomorrow. You can always engage in conversation with me in the comments below or on Twitter/Facebook, I’m here to make sure everyone is aware of what is going on.
Until tomorrow, “When clouds appear like towers, the Earth is refreshed by frequent showers”
Adventure Brett (or Forecaster Brett?)