Category Archives: Story

An outbreak looms

Unseasonably warm temperatures have embraced the Eastern United States. While many people are undoubtedly basking in the warm sunshine, there are probably a few people out there thinking “this isn’t quite right!” One of those people is Mother Nature, who is preparing a dose of reality over the weekend.

A broad upper level trough in the northern Plains is starting to move incrementally eastward, and over the weekend, there is going to be a bit of a repetitive pattern at the surface, with a low developing in the southern Plains and shifting towards the Great Lakes. The first such system has already developed and is halfway through it’s course, with some showers and storms in the mid-Mississippi Valley and snow in the Upper Midwest.

As soon as Saturday morning, the next area of low pressure will crop up around the Oklahoma Panhandle and start moving to the east northeast. This version will have a little bit more upper level support, which means more cold air pulled in from the north and more moisture drawn in from the Gulf of Mexico. Given the warmth that is seated in the east and southeast, that’s a recipe for, you guessed it – severe weather.

This is an outlook for day 3, or Saturday, featuring a very large “slight risk” though I suspect by the time Friday morning rolls around, there will be a red “moderate risk” from about Memphis to Shreveport.

The central low pressure is in the colder part of the system, and the tornado threat won’t be extreme, but strong straight line winds seem like a sure thing.

This is going to be the first wide spread severe event of the year, and it is the always underrated squall line variety. While tornadoes cause a great deal of devastation, they often do so in isolated locations. Squall lines like the one expected this weekend touch a lot more lives, even if they don’t necessarily produce the destruction a twister would.

Oh, and on the northwest end of this feature? We’ll be looking at a late season snow storm for the Upper Midwest, with some locations looking forward to a foot of snow over the weekend, on top of the 3-6″ they are seeing tonight with the first wave.

A tale of two outputs

A quick moving, potentially hard hitting system is moving through the Mid-Atlantic this afternoon and evening is proving somewhat enigmatic for the model outputs. Let’s take a look at what I mean by that, and just look at where the NAM and GFS differ so wildly.

Look at the precipitation outputs for the 06z time frame, or about midnight tonight, when the storm will be battering Long Island and Southern New England. The NAM, with robust precipitation totals is on top, the GFS, which is more docile, is on the bottom.

That’s a pretty significant difference in the amount of available moisture for this system, and this lack of clarity is reflected in the confidence forecasts from the NWS on Long Island. Here is the max and min snowfall possibilities for the forecast area.

That’s an 8 inch range in New York City, which is obviously an untenable situation for the Nation’s most populous region. This forecast is nearly 10 hours old, however, so maybe we can hone it a little bit. The best way to start is to see how the models have initialized. Here is the radar for the Ohio Valley, followed by the models in the same order, so you can see how the performance looks to start.

The radar is a bit further advanced than the model period noted above, but the trend is still easily discerned. The NAM is doing better with the voluminous precipitation, however the NAM is a full state too far south with the placement, with the heaviest rain and snow in the Ohio Valley, rather than over Tennessee. If this trend continues, that means that the precipitation as it arrives on the coast will also be further to the north, or as the case may be on the coast, further inland.

One thing that we can see from the observations is that the rain-snow line, the position of the low and the temperature profile are pretty much in line for both the NAM and the GFS. I’ve drawn the rain-snow line on the map below, while the center of low pressure appears to be near Jackson, Kentucky.

This bodes poorly for a “light snow” event, though with so much moisture on the north side of the feature, it seems possible that the accumulations will be blunted by warmer temperatures at the middle layers.

So yes, there will be more snow than the GFS expects, but not as much as the maximum accumulation that the Weather Service fears. I would guess most of the region, excluding the typically warm Montauk and Hamptons will be in the 5-8″ range for accumulation. The big winners will likely be the Berkshires and places in land. Half a foot of snow can sure tie things up, but at least it isn’t 10 inches, and at least it is coming on a holiday weekend.

One-Two Punch For Northern Plains

The Northern Plains/Upper Midwest had been persistently cold the last couple of weeks until a change in the pattern finally warmed things up a bit over the last 2-3 days. An arctic boundary moved through and temperatures tonight are expected to plummet to near zero here in MSP and well below zero further north. The big story, however, is what the models are churning out for Sunday into Tuesday. An area of low pressure that’s currently over the Aleutian Islands will finally shift into the Pacific Northwest Saturday afternoon then continue eastward over the Northern Plains on Sunday. The main track of snow associated with this system will be over ND and into Northern MN and current model guidance is churning out 6-12″ with it. A second system looks to affect the region Sunday night through Monday, but with it still 72-96 hours out, the confidence on this system has been less than stellar, with the main swath happening anywhere from IA/Southern WI to SD/Northern MN. Another 6-10″ looks possible from this second system, but it remains to be seen who will get the bulls-eye from this activity.

Minneapolis is usually a bit warmer

Darren Rovell is the ESPN sports economics reporter, and he had this rather mean spirited tweet before the game was played or any of the numbers were released, Until Friday and Saturday, it really wasn’t as bracingly cold, and frankly, this time of year, it’s not generally this cold.

While the game was, far and away, the coldest Super Bowl in history (that is to say, the city temperature… it was played indoors) it was also a solid 20 degrees below normal, and it was in the mid 40s the week before.

It’s hard to convince people that Minneapolis isn’t generally this intolerable (weatherwise, it’s wonderful otherwise), especially if visitors are still looking at the local forecast. It’s not expected to reach normal for at least a week.

Congratulations to the Philadelphia Eagles on their victory!

January Forecaster of the Month

The big story this month was the icy cold that gripped so much of the country. Yes, there was extensive discussion of the bomb cyclone off the east coast, which made many people giggle, but the weather impacts were no joke. In the icy grips of winter, Accuweather kept their cool, and was the easy winner of the forecaster of the month title.

I hope you like this weather

The middle of the country is experiencing a bit of a temperature renaissance, but after a Clipper moving through the western Great Lakes will pull some cold air behind it, and that’s essentially the pattern for about 10 days. Mostly cold, followed by some bouts of warm weather, shortly trailed by a burst of snow and more cold air.

There is a blocking pattern over Alaska right now, which is part of the reason that the Continental US has been able to avoid big systems for a week or so. More relevant is that the wave pattern across the middle latitudes is fairly static. Here is the upper level chart at the GFS initial time:

The big difference between the current chart and the one from a weak from now is the absence of that arch over the Bering Strait.

The other components, like the strong jet over the western Pacific, a ridge in the eastern Pacific and a general trough through the eastern part of the country remain the same. That’s not a recipe for a fungible weather pattern.

With a fairly consistent upper level stream over the center of the country, don’t be surprised if there are a few more busts of snow this week in the Western Great Lakes. The rest of the country should think about getting comfortable with their weather for a little while.

The thaw will come to an end soon

One of the unusual things about the recent snow storm that strafed the Midwest is that it wasn’t accompanied by a slug of cold air to make it extra miserable. In fact, nearly a week later, it’s in the mid to upper 40s in the Twin Cities, and in the 60s in places like Washington DC.

Never fear, I have come bearing bad news. It’s going to get cold again, and it will do so as soon as next week. Here is a look at the 8-14 day outlook.

While Washington won’t see temperatures plummet, they will return to normal, while the Upper Midwest will definitely see some crashing temperatures. The interesting thing is that it won’t be on the heels of a big storm in the Plains, but rather a fairly significant developing low in northern Quebec. A very active cold front will develop along that line of above and below temperatures, from Virginia to Houston. More snow is possible in Nashville next week with rain possible in Atlanta.

And cold air for the Twin Cities and Chicago. Very, very cold, once again. Enjoy the warmth while it lasts.

Minneapolis gets hit by heaviest snow in 6 years

It snowed…. more than a foot

A post shared by Ryan Henning (@victoriawxrhino) on

I mentioned a couple of days ago the the center of the country was preparing for a large, dangerous storm. I can assure you that the wintry portion of the storm delivered. Above, you can see what I saw when I opened the garage at my house in the southwest Twin Cities suburbs. While this caption is a well executed pun, the wind actually caused snow to drift away from this part of my house, and the total accumulation in my neck of the woods was around 15 inches.

Here is a map from the Weather Service, highlighting some snow reports, so you can see where the heaviest accumulations were. The oranges and yellows are the greatest totals, Check out some values for those dots here.

As I noted in the post headline, this was the largest snow total at Minneapolis-St. Paul International Airport in 6 years, since December 2011. The significant snow fell in places like North Platte, Nebraska and Goodland, Kansas, as well, and while it impacted fewer people, you can believe that the driving winds and empty country made it much more treacherous.

The good news is that the region now has several days to dig themselves out of the heaping snow. For the next week the central Plains look as though they will enjoy a great deal of sunshine to help whittle down the fresh snowpack.

Massive spring-like system clobbering the center of the country

One of the hallmarks of big March or April storms is that they tend to come with a couple of different faces. There is often a wintry component, as well a severe thunderstorm component. We have that with a huge system moving through the Plains tonight.

The snow has been impressive in the Front Range of the Rockies to the Black Hills where some locations have received up to a foot, particularly east of Casper in Wyoming. That’s to say nothing of the snow from this same storm in the higher terrain, where the Wasatch universally received a foot, and the mountains near Grand Junction got THREE feet.

Scale: Anything orange or darker received over a foot. Dark red – 36″ Source: http://www.weather.gov/crh/snowfall

This is all before the system really got wound up. The northern Plains are widely believed to be winter wonderlands, but in truth, big snowfalls are few and far between (the cold is the truth, though). That makes the snow expected to fall from central Nebraska, through Iowa and Minnesota and into the western Great Lakes something truly impressive.

This is a particularly difficult forecast in the Twin Cities, which has recently seen an incredible streak of busted forecasts on major snow events, and are now situated along a very sharp gradient for forecast snowfall totals. If current forecasts hold, the southeast metro will receive over a foot of snow, while the northwest metro might only see an inch or two. This forecast is from earlier in the afternoon, but I assure you, the latest model runs will only serve to sow more confusion.

On the other hand, we had tornado watch number 1 for 2018. It took a few weeks, but it showed up in the Texarkana and Fort Smith area during the evening, and TW 002 showed up just to the east, and remains on going. Here is where the first watch of the year showed up.

Unfortunately, there have been a few reports that indicate these watches and the attendant warnings were warranted. For example, there were reports of damage near Winnsboro and Dekalb, Texas,.

While the severe weather is ongoing, including some tornado warnings in southern and western Arkansas, particularly in the Hot Springs and Pine Bluff areas, the severe weather won’t last much longer. As the low winds up in the Upper Midwest, there won’t be the same clash of air masses in the more succulent lower Mississippi Valley air. There might be thunderstorms, but they won’t match the intensity seen tonight.

Keep an eye out for those severe thunderstorms tonight, especially in Arkansas, and prepare for a tough day of shoveling from North Platte to Wausau tomorrow morning!

Another round of cold air

By my count, this is the third significant incursion of very cold air into the part of the country east of the Rockies. The first came after Christmas, plunging temperatures down into the double digits below zero into the middle of the county, and eventually east towards the coast.

The second round came early last week, and after a bit of a reprieve, it’s coming back just a couple of days later. One of the more visually intriguing parts of this particular round of chill is that a simple look at the surface radar will tell you just where the cold air has advanced.

These cold air pools making their way into the Plains are part of high amplitude waves, meaning there is a bit of a dichotomy. For it to be cold in Kansas City, it must be warm elsewhere. In this case, that somewhere else is in Alaska, where temperatures have been significantly warmer than normal all winter!