Strong storm predicted for next week abruptly disappears from model guidance

Well, that just shows you how difficult the weather is to forecast a week in advance.

For the last 48 hours, the GFS has been consistently predicted a very powerful low pressure system maturing over western Ontario/eastern Manitoba and moving northeastward into the Hudson Bay. This system looked as though it could produce some very windy, rainy conditions in our state next week, if not severe thunderstorms.

Fast forward to today, and the last three GFS runs have completely nixed this feature from their forecasts:

These images all depict the same timeframe (around 1PM EDT on Thursday November 5th) as forecast by the GFS model run yesterday at 8am, then yesterday at 2pm, then yesterday at 8pm, then this morning at 2am.  Note that the last time the storm is depicted is yesterday's 8am run.  After this, it vanishes completely. 

We're still in store for a warm up, but the cool down that should follow may not quite be as sharp, and certainly shouldn't be as climactic.

Another VERY powerful storm system to target the Great Lakes next week - Michigan in warm sector

The GFS is once again predicting a that a potent mixture of warm, moist air and cold, Canadian November air will spawn another gale-storm in the Great Lakes region next week.  This time, however, Michigan should be in the warm sector rather than the center of the low.

Wind speeds in the upper levels of the atmosphere could reach 120kts with this system.

The upper level winds are rather unique in regards to this system. The obvious feature predicted is the positively-tilted trough descending all the way to Nevada before cranking the winds northeastward to very high levels. However, another not-so-obvious upper level disturbance is also being predicted. This is what's referred to as a "short-wave" trough; it's nowhere near as prominent as the long wave trough to the south, but it can have an even greater impact on the weather local to it. This particular trough should enhance what is an already super-strong 120kt+ jet core.  The result is what you see predicted below:

This type of storm system could produce severe thunderstorms in our area should there be enough instability for them to get off the ground. Note that this is a big if - instability at this time of year is usually hard to come by, even with temperatures in the upper 60s/low 70s at the surface which is what's being predicted.

It remains to be seen just how much moisture this system will be able to suck up from the south, and what the timing of its arrival will be. If it were to have access to as much moisture as the current system overhead right now, I'd be a bit concerned, but this system won't have the remnants of a hurricane to work with and will rely on whatever it can accrete from the Gulf of Mexico. That isn't to say there won't be enough to make for a damaging wind threat, but it can mean the difference between a November gale and a November 17th 2013-style tornado outbreak.

Rainy, windy mess arriving, going to give Michigan grief for the next 36 hours

As I stated in earlier posts, tropical moisture from the remnants of Hurricane Patricia is streaming into a rapidly-deepening cold-core storm system currently spinning to our west.  The result is what you see below:

This mess is going to essentially drench the entire state of Michigan with tropical rain and high winds for the next 24-36 hours.  This is one of our typical "November Gales", and what you would expect to see at this time of year.  If it were frozen, it'd be a major blizzard. Nonetheless, power outages are possible in some areas due to the high winds as they may cross severe thresholds in some areas. Be on the lookout for downed lines and flooded roadways, and stay safe.

A good rain likely mid next week

Remnants of the most powerful hurricane ever recorded in the western hemisphere will likely feed a typical fall cold-core storm system which should develop to our north and west next week. The result is that said storm should deepen and intensify just as it spins over Michigan:

So far, the models are modest about precipitable water values, so flooding shouldn't be a major concern.  A couple days of modest to at times heavy rain is likely, though.

Powerful storm system to target Michigan next week

More rain, potential thunder and very strong winds are going to be on the way for the middle of next week. Several runs of the GFS and ECMWF are predicting that a very potent storm system will form to our west and drench us.

The most impressive feature of the storm is the low-level jet - southern winds >50kts are predicted over Lake Michigan.

If this were summer and temperatures were warmer, severe weather would be a major concern, but as we're dealing with cool fall air, there likely isn't going to be enough fuel for any sustained severe storms. A brief strong thunderstorm forming over the lakes is very likely, though. I'll be keeping my eye on this one for sure, as a rare scenario like November 17th, 2013 can't be ruled out quite yet. So far, though, indications are that timing/instability won't be favorable for an event like that, and this thing should be churning out lots of convection prior to reaching maturity, which would also temper such a scenario.

What's most interesting to me is that our fall weather pattern isn't deviating that much from our summer pattern in terms of storm track; if anything, we're seeing more storm systems target the area. With a record-breaking El Niño in the south, we're likely going to see a warmer than usual winter, defined by low temperatures in the upper teens to twenties on average, with brief thaws of 30-40 degrees. Should this stormy pattern persist into the winter months, we'll likely be looking at a few potentially powerful winter storms dropping heavy snow, layers of ice, or even rain depending on what sector we wind up in and how cold/warm the temperatures will be that surround it.

Much warmer temperatures this week, but also a chance of - yes - thunderstorms

That's right.  We may not be done with thunder and lightning quite yet after all. Despite a very brisk morning here in the thumb, temperatures are expected to rise into the 60s. This should create enough temperature differential to ignite thunderstorms in some areas of the state.

This morning's NAM4KM run is the most aggressive regarding thunderstorm development over lower Michigan this evening.

The warm-up will continue after today.  By Wednesday, some places to the south may even be looking at temperatures in the mid to upper 70s once again.

Time to be thankful for the Great Lakes

It's going to get cold this weekend.

So cold that snow flurries are going to be likely in places close to the lakeshore throughout the state. These lake effect flurries will be driven by some very cold (for this time of year) arctic air being driven down into the midwest.  Eventually that air will make its way eastward, and things will start to warm up again.

However, it's interesting to note just what impact the lakes have on this air and just how cold it will get here compared to other states:

Take a look at the NAM's surface temperature prediction for New England on the morning of October 19th.  Temperatures in parts of New York and Pennsylvania are expected to sink as far as the low 20s in some places. This is also expected in states to our east as depicted by the first picture. By comparison, we're looking at lows in the upper 20s over the next few days. We can thank the warm lake temperatures for this. In the spring, cold lake temperatures tend to keep temps cooler in Michigan as compared to other areas of the country, but in the fall and early winter, the opposite effect occurs. This of course is also responsible for lake effect snow, and even thunderstorms. Last night, northern Huron County actually had a heck of a light show. A very strong thunderstorm, complete with 40-50mph gusts, blinding rain and LOTS of lightning erupted over the eastern Saginaw Bay and drove across Caseville southward into the eastern portion of the county. Temperatures were only in the mid 50s near Pigeon, but it's safe to assume temperatures over the lake were a bit warmer. Factor in the naturally higher humidity over a body of water, and you have enough instability to drive a storm like this.

A freeze watch remains in effect for most of southern lower Michigan (save for the western shoreline). This is because what's known as a "killing freeze" is expected in the next 36 hours; two or more hours at 28°F will basically destroy all fruits and vegetables still outside. Most have already ended their growing seasons, though, and this sort of thing is kind of a given around this time of year in Michigan. I expect this to be upgraded to a warning later today.

First truly cold air of the season arrives this weekend

It's that time again. Where we live shall be revealed once more.

2am run of the GFS, valid for this Sunday at around 8am. Temperatures below 30°F are very likely.

8pm run of the ECMWF, valid for this Sunday at around 8am.  Once again, temps below freezing are predicted.

Run-to-run consistency of both the GFS and ECMWF models is predicting temperatures well below freezing by the early morning hours of Sunday, October 18th.  The GFS is especially aggressive, predicting widespread temperatures in the mid-to-upper 20s. The good news is that temperatures should be back in the upper 60s by early next week.

Yee-ha.

Rain, thunderstorms likely throughout the state late this afternoon into the overnight

What could be one of the last days of thunder this year will come within the next 18-20 hours.

A cold front is making its way south east across the lower peninsula and with it should come widespread rain and thunderstorms.  A band of precipitation is already forming to the north, drenching areas of the U.P.  It will be moving into lower Michigan as the day progresses, promising to make conditions wet.

Temperatures should reach the low to mid 70s by this afternoon across the southern portions of the state and upper 60s to low 70s across the central portions.  By tomorrow they'll be trending back toward the 50s with lows in the 40s.

Bearing witness to a once in a lifetime phenomenon - Much of South Carolina is being washed away

Although I'm deviating from Michigan weather, this needs to be talked about. I've put off posting about it until now for numerous reasons (super busy at work among other things, but mostly I wanted to see just how far this would go), however we're to the point where I think we're crossing a line from a terrible disaster to the altering of geography.

Courtesy of CNN.

The term "disaster" doesn't weigh enough to apply to what's going on here. The news media keeps using terms such as "historic" and "unprecedented" and the latter only begins to apply, while the former is almost laughable in its arrogance regarding what humankind has seen. The threshold for "historic" was crossed by October 1st. The only term that can be used to describe the situation today is "cataclysmic". By the end of the week, we're going to be crossing into "biblical."

After that, I'm not sure what's going to be left - both of descriptions and of the state of South Carolina.

The phenomenon that's causing this is a bit insane. A fairly typical, average, not-even-that-powerful cold front was making its way across the country last week. This was the same cold front that caused some rain here. As it reached the east coast, a truly remarkable and God awful thing occurred. It ran into Hurricane Joaquin.

Satellite imagery taken from October 3rd.

The cold front stalled, and a surface low developed. It began to accrete a truly terrible amount of moisture from the hurricane, and began to dump that moisture as precipitation over the eastern US. It wasn't that strong, but it didn't have to be. Unlike the 1993 Storm of the Century, which exploded as a meteorological bomb and gave it enough power to tow its moisture all the way to New England from the Gulf of Mexico, this one acted as a giant bucket rather than a fire hose - it merely picked up water out of the ocean and dumped it over the coast. Also unlike the 1993 event, this water is falling as liquid rather than snow, and while 20 inches of liquid rain would equate, on average, to between 160-240 inches of snow, it's hard to say which would be worse to endure. One way or another, whether it wants to or not, South Carolina is going to become the benchmark for the first scenario.

I can't overstate just how bad this is. When you think of terrible weather disasters of the last 20 years, Hurricane Katrina and the associated flooding in New Orleans is usually what comes to mind. However, what you have to understand is that what happened in New Orleans, as terrible as it was, was an entirely man made disaster, catalyzed by a natural phenomenon. Hurricane Katrina was a very powerful monster which produced a nearly 30 foot storm surge and inundated the coastline, but it didn't come CLOSE to procuring nearly two feet of water over a diameter greater than 80 miles. Remember that these aren't just feet, but *cubic feet* of water. Taking that into account spread over an 80 mile radius, that's 211,200 cubic feet of water, or 1,579,776 gallons of water confined to that stretch. Note that this is ONE SINGLE STRETCH and not the square mileage, which I'd estimate to be closer to 4800-5000 square miles.

I'll leave that calculation to someone else.

So what kind of damage is occurring from this? Besides the usual staples of flooding such as houses, cars, belongings, pets, and people washing away, South Carolina is dealing with issues such as dam breeches. Millions are stranded as roads and bridges are destroyed by the flood waters. A HUGE 70-mile stretch of north and southbound I-95 is closed between I-20 and I-26. To compare for southeast Michiganders, that would be like closing I-75/U.S. 23 from the southern junction of I-675 in Saginaw County all the way down to the I-96 interchange in Livingston County. No statements have been made as to when the road might reopen, nor what kind of damage has been done.

The green arrow points to the direction the remnants of the low are turning, with the red line representing the hardest hit areas.

The worst part of all this? This crap's not even over yet. This system is still spinning off the coast of South Carolina and threatens to continue to drop rain across the northwestern portions of the state. This is particularly bad for the places already inundated, as this water will wash downstream and out to sea over the coming weeks, directly through the worst-affected areas. With dams already being breached, roads and bridges washing away, and millions of people stranded, there's no telling just what will be left when the waters finally reach sea level again.

This event is going to change more lives in this region than I can possibly come close to empathizing with on an individual level, and is going to make Hurricane Katrina look like a weekend vacation by the time it is over. God go with South Carolina, because the devil certainly is there right now.

Joaquin strengthens to major hurricane as it grazes the bahamas - may affect east coast as tropical storm

Not related to Michigan weather per se, but this definitely could affect our weather patterns in the coming weeks so it's something to pay attention to. Hurricane Joaquin has strengthened very quickly to a powerful Category 3 storm, and is set to strike the eastern shores of the Bahamas. It remains to be seen just how hard of a hit it will be, but nonetheless, my thoughts and prayers are with our island cousins to the southwest.

Latest strength/projection of storm, and warnings currently in place.

12z GFS projection of storm (winds 10m above ground)

The latest GFS run has the storm tracking up the east coast and potentially grazing New England as a tropical storm.  I'll be keeping an eye on this because gale force winds on the lake are not unheard of during these types of events.  There's also the extremely slim chance that its remnants could slide into our area and cause some heavy rains, but as of right now all of the models put the track back out to sea.