Not quite a drought, but it is dry

There has been no shortage of severe weather this season, but it hasn’t been accompanied by broad swaths of rain. Even after a wet spring, the Heartland is starting to get browner. The below normal spots are fairly piecemeal, which is a good indicator that isolated thunderstorms have roamed the country.

Below, see a comparison of the drought monitor from this week versus last week, and you can see just where the increasingly crispy lawns are located.

La NiƱa years tend to be drier years for a lot of the country, so there isn’t a lot to read into on this in terms of long term ramifications, but for the short term, it will may lead to a difficult growing season for some crops. Corn, famously, likes dry, hoy summers, and after the soggy spring, it’s coming around robustly in some parts of the Midwest.

There has been quite a lot of rain in the west of late, but as you can see, there was barely a dent in the drought. “dry” is different than “drought”. Dry can be turned around in short order with a couple of good rains. Drought is a lot stickier. It needs some above average rainy months or seasons in order to start making a dent. In fact, one really good rain storm might be counter productive, with run off and flash flooding becoming a problem on hard ground that is not capable of taking on the rain water.

It looks like the southwest will have a wet season, so that long term moisture will be good for recovery. Also note that there has been some retreat of the drought in northwest. It’s not necessarily a great outlook, but it’s a little better than it has been for a while. The drought in the west may lighten a bit, and by the end of July, Mississippi Valley lawns will be green again.

Cool and wet in…. the Desert Southwest?

Everything being relative, of course, there was a rare sight on the CPC page. The Desert Southwest, particularly Arizona and fire ravaged New Mexico are expected to see below normal temperatures and above normal precipitation next week. This qualifies as good news, if it dents the drought and doesn’t fully inundate the region.

A combination of factors will lead to this tandem of potential results. First, the monsoon is expected to get a bit more active this week, producing thunderstorms across the southern Rockies between Arizona and New Mexico. Tropical Storm Celia is spinning off the coast of Mexico. It poses no threat to land, but will generate mid level moisture accessible by the air mass over the Land of Enchantment.

Second, an area of low pressure moving through the Northern US is going to leave a stationary front across the Plains, which is going to connect with the dry line and monsoonal flow in New Mexico and Arizona. Robust shower and thunderstorm activity is anticipated throughout much of the week.

Lightning is a threat to fire prone parts of the landscape, and dust will be a concern. Any heavy rain, especially in the undulating terrain could lead to flash floods. Despite these individual perils, it seems like the rain and the cooler temperatures are good things.

Dangerous heat spreading northward

As noted in the forecast for Grand Forks forecast, some oppressive heat is getting ready to surge to the north for Fathers Day and the beginning of next week, It’s already quite hot in the south central US, but after somewhat cool springs, it will be a sudden shot of summer for many in the northern US.

Frequent bouts of severe weather have swept across the region. Strong storms have afflicted every state from South Dakota to Michigan, and even the tier to the south in the last few weeks, indicating for those that didn’t know that the jet stream has lingered over the northern US through much of the spring. The stormy activity and jet’s sag have kept temperatures cool.

Now as we approach the peak sun angle, and the warmth of June, the jet is weakening and starting to wobble. A sharp trough in the Pacific Northwest is going to be a factor in lee troughing in the High Plains, but the troughing will be well ahead of the low, giving a lot of runway to the southerly flow and the warm air that follows. Triple digits may reach the Canadian border.

Strong storms are continuing through the eastern Great Lakes after the latest round of severe weather that started earlier this week in Wisconsin and Illinois, but after today’s (enhanced risk) threat of severe storms In New York, Pennsylvania and surrounding areas, the severe threat peters out. A wonderful side effect of the weaker jet is a lower likelihood of strong storms, and this bout of severe weather looks to be the last for at least a few days.

May forecaster of the Month

May was one of the busier months we have had in quite some time, so there were a lot of data points when trying to identify the top forecaster. Most of the really rough weather this year ended up falling in the north central US, which is definitely atypical, and we had some very bumpy forecasts along the way. One thing that is not entirely unheard of is a solid month of May from The Weather Channel, who alway seem to shine during the transitional seasons, and those times of year with the busiest weather. Congrats, TWC!

OutletForecast Wins (year)
National Weather Service4
Accuweather3.83
The Weather Channel3.83
Weatherbug3.33
Victoria-Weather2.66
WeatherNation2
Forecast.io0.33

Above average Atlantic, Below Average Pacific

Welcome to hurricane season, everyone! For the first time in quite a while, the Atlantic has managed to avoid having a named storm crop up before the season started, though nevertheless, a busier than normal season is expected this year.

Even as this post is written, the remnants of Tropical Storm Agatha are being monitored for redevelopment in the southern Gulf of Mexico. It would be an interesting way to kick off the season, but the more traditional means of tropical development are, as now, pretty quiet across the Atlantic.

That portends to activity picking up later in the season. Even though this is the beginning of the tropical season, historically the most active period in the Atlantic comes at the end of summer, when the oceans are at there warmest. If the season waits to start and gets busier as it goes on, that will lead to a rough August and September.

Despite Agatha’s emergence in the eastern Pacific, the NHC projects a quieter than average season in the central Pacific. This is particularly important for both Hawai’i and surfers who come looking for big swells around the islands. There aren’t many other land masses that stand to be impacted by tropical features in the middle of the ocean, and even in busy years, Hawai’i isn’t impacted with much frequency.

Of course, with any season, what we remember is the storms that make landfall. Most residents of the Caribbean would agree that the Atlantic can be as busy as it wants to be, just so long as the storms stay out to sea and leave their islands alone. A quiet season in the central Pacific means nothing if one rogue cyclone nails Honolulu.

One last note. The beginning of hurricane season is also the dawning of meteorological summer. We made it, everyone. Happy summer!

Slow moving Agatha threatens Mexico.

The Pacific hurricane season gets an earlier start than the Atlantic, historically, thanks to abeing a vast body of water that doesn’t see the same changes in temperatures the Atlantic can undergo. It’s not terribly surprising to see Tropical Storm Agatha lurking off the coast of Mexico, but what is surprising is that this feature is expected to back up into the Mexican coast.

Pacific storms tend to start in this area, but the tropical wave they gear up from tend to maintain some momentum, allowing them to shift off to sea. Agatha is nearly stationary, and looks as though she will begin to move poleward earlier than is typical in the Pacific, and back up into Oaxaca.

If there is any good news, it is that Agatha isn’t a large storm. She is expected to become a hurricane before making land fall, which means the wind will be stronger along the beaches of southern Mexico, but the breadth of territory affected by the associated heavy rain should be mitigated. Additionally, that Agatha has backed up and moved northeast fairly recently suggests that storm surge will not be a primary concern either.

Even so, it looks like the storm won’t landfall until Monday, and changes are always possible. Notably, a storm over warm waters always possess the ability to get stronger, though of course, we hope that doesn’t happen.

Severe weather again, but a different story

Last week, a two day storm event brought rough weather first to the Twin Cities on Wednesday, followed by this howling, apocalyptic dust storm to Sioux Falls. There were tornadoes in Minnesota, South Dakota, Nebraska and Iowa, but the real show were a couple of bowing lines of thunderstorms that rolled through each town.

There was more severe weather on Thursday in the Upper Midwest and into the Great Lakes. Severe watches were out from Missouri to Kentucky, and also popped up from Minnesota into Wisconsin and Iowa. There was a particularly different feel to these storms than the ones last week, though, and much of it has to do with the orientation of the upper level pattern.

Last week, the upper level pattern featured a brisk south to north jet streak butting against a stout ridge in the east and situated on the eastern flank of the trough that was allowing the storm system to develop. One of the results was a very narrow opportunity for a warm sector of any consequence, but a lingering “warm front” boundary was the perfect environment for bowing lines and derechos, which is what we got, twice, last week.

This week, the system brought a wider warm sector, and was able to advance cold air. Initially, on Thursday, it lead to some significant hail, such as what I saw in downtown St. Paul Thursday afternoon.

As the storm moved on, the progressive low with access to warm moist air was a ripe environment for tornadoes, of which one struck Gaylord, Michigan. This storm was an EF-3 tornado, which is quite strong in general, but in particular for northern Michigan.

The wave, which again, because it was more open than the one from last week, has continued it’s course, and has allowed the parent area of low pressure into Canada. But again, because it is advancing, has brought cold air in on the back side. Even tonight, there is an ongoing threat of some severe weather thanks to a ranging cold front from the eastern Great Lakes to Texas.

Clashing air masses and strong jet streams are good environments for severe weather. Differing patterns and flows might lead to different results, but as the last couple of weeks have shown, they can all be dangerous.

April forecaster of the month

I’m as shocked as you are to see that I am able to put together this award ceremony in a mostly timely manner. It features a return of last year’s overall champion to a spot at the top. I have to commend Weatherbug on their growth through the years. Very often, they were tied to a Weather Channel forecast, and made changes with deleterious results. Now, in 2021, and at least in April 2022, they seem to have figured things out. Congratulations, Weatherbug!

OutletForecast Wins (year)
National Weather Service3.5
Accuweather2.83
Victoria-Weather2.33
Weatherbug2
The Weather Channel1.83
WeatherNation0.5
Forecast.io

Dangerous weather through the weekend

The weather has certainly been active this spring, and especially so if you consider how busy the Storm Prediction Center has remained since December of last year. Fortunately, since the devastation wrought in western Kentucky, southern Illinois and many places surrounding, we haven’t seen the type of devastation that stays in headlines for days.

That’s not to say the storms have been any less violent so far this year. In fact, there was an EF-4 tornado last month that swept through Winterset, Iowa, claiming the life of 6. That was as strong as the Mayfield, Kentucky tornado. The substantive difference is that Winterset is not as large a town as Mayfield, but the Winterset tornado also did not have as long a track as the western Kentucky storm.

A look at the tornado tracks this year show that, while there have indeed been many twisters this year, most of them were weak, and a lot of them were in Dixie Alley.

By Supportstorm – Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=115162410

By and large, those storms are avoiding the largest population centers, and haven’t been particularly virulent, as tornadoes go.

The pending change is twofold. First, tomorrow, the threat for significant weather targets an area including Tulsa and Wichita. Over the weekend, the threat includes the Dallas Fort Worth area. In general, the storms are going to affect a more populated area. Second, the storms are going to possess a notably higher threat for strong tornadoes. The hatched area in the SPC’s outlook for tomorrow indicates a threat of large (EF-2 or greater) tornadoes in an area. Those are big twisters dangerously close to Kansas City and Oklahoma City, potentially.

Big storms in more populated places remind us that we are definitely in severe weather season, and it is time to keep an extra eye on the sky.

A sluggish, stormy spring

Everyone loves to talk about the weather, as I’m sure you do (you’re here at this site, after all) but depending on where you are this April, you might have a decidedly different conversation. If you are in the southern US, you are probably talking about how stormy this year has been. In the north, you probably can’t get over how chilly things have remained all spring.

For an explanation, we need to look even bigger than we usually do, beyond the confines of the Contiguous US. The answer lies in the jet structure across the United States. As you may already be aware, bigger features are more challenging to move in the atmosphere, and there is an enormous trough that keeps recycling and sustaining itself, and the base of that trough has run across the northern United States.

Take a look at the big picture, the jet forecast for this afternoon.

Typically, if I am looking at the US forecast, I would note the deep trough coming to the west coast was, or even noting the ripple in the northern Great Lakes, but when taking into account the spring writ large thus far, and unfortunately for the coming weeks, the immediate notice is that the larger waves are the ridges bracketing the United States.

There are semi-permanent features in the ocean, certainly, including the Bermuda High, and the existence of the ridges are not unusual. Some things that are factoring into making this spring unusual is the amplitude of the trough over North America. It should be starting to retreat into Canada, bringing some calm to the south, and allowing warmth to filter back north, but the mean trough is instead littered with localized troughs like the one set to upset this weekend.

Another peculiarity is how weak the trough in the Gulf of Alaska is. The Aleutian Low is as permanent s the Bermuda High, but right now, and for a while, this feature has been replaced by transient features moving into the Pacific Northwest. This gives this larger continental wave more breadth, and makes it more difficult to move.

With the mean trough over the US running through the northern tier of states, it is penning cold air that same swath of the country. On the same note, the sun is getting stronger, so warmth is building south of the jet. This clash of air masses at the surface, when coupled with the relatively shorter waves moving across the nation, is making for an active storm season, and a chilly spring, depending on what side of the divide you are on. Eventually, the pattern will break, but there isn’t an immediate sign of that happening quite yet.