The remnants of a weak tropical feature came ashore in Texas over the weekend, noted only in reference to how quiet the Tropics have been this season. This weak, nameless blob was about all that had troubled North America this summer so far. It gathered a lot more attention overnight into this morning by dumping torrents of rain on the Dallas metro, leading to flash flooding throughout the Big D and Fort Worth.

At least 2 inches of rain have fallen in broad swaths of North Texas and up to 8 were estimated in some spots, making city streets waterlogged and impassable in some places. Radar shows that more rain is coming, though fortunately, Fort Worth should be drying out.

Flash flooding is different than river flooding, in that the onset is much more rapid and isn’t necessarily confined to existing waterways. River flooding can be planned a bit better for evacuations and bracing for the impacts of rising rivers, but flash flooding, like the rain in Dallas, can happen with a lot of rain coming in just a few hours, and is not as easy to anticipate.

There are two particular amplifiers of flash flooding. One of them is the increasingly paved surfaces we find in urban areas. Water pools, unable to drain from roadways, and can cause vehicles to hydroplane or even float. If the water is moving, for example if a nearby waterway has spilled out of its banks, or if the inundated roadway slopes, just a few inches of water are enough to move a vehicle. If water is deep enough, it can cause engines to stall.

The worst case scenario for flash flooding is usually found in hilly or mountainous terrain, such as what happened in eastern Kentucky this summer. Rainwater is channeled into valleys, causing existing rivers and creeks to rise quickly, and sweep away mud, trees and edifices in the water’s path downward. Unlike normal river flooding, which arises from water coming downstream after snow melts or a long, wet season, flash flooding happens in an instant as water flows downhill. Some of the deadliest flash flooding instances in the US occurred in Oregon and Colorado.

Heavier rains are a response to slow moving storms with higher dew points, and are possible even when severe weather hasn’t occurred. It’s always important to stay aware of your surroundings, and not pass through standing water, because you never know what lies beneath.

Late August usually brings out the posts about the coming tropical season and the increasing threat. The peak of the tropical season is less than a month out, and while the NHC continues to forecast a busier than normal season, the Atlantic remains quiet. So we turn our attention to the rest of August in the continental US.

The 8-14 day outlook from the CPC has much of the country in below normal temperatures. This is accompanied by above normal precipitation in the same regions, and as a reminder that summer is still around, a heat wave on the west coast.

Oceans continue to warm through the summer as the sun angle stays strong, which is why late August and September are busiest in the Atlantic, but over large landmasses, air masses are more vulnerable to changes. While the sun is warming the oceans, the angle is reducing, and the jet starts sinking south. There is more variability in the weather pattern, and when there is variability, there is the threat for thunderstorms.

There might be some instinct to believe that the extremely divergent temperatures relative to normal found on the coasts versus that in the middle of the country. Looking at the upper level pattern, though, this doesn’t quite seem likely. Typically weak summertime flow is going to continue until late in this outlook period, which means these cooler temperatures will probably be a result of moisture and cloud cover thanks to an array of surface perturbations.

Shorter waved features are more spurious, and is why there is less confidence in the below normal temperature field than with the warmer regions, which are a result of strong jet stream ridges in the forecast. There isn’t the full level cold air mass in the middle of country to provide the clash of airmass you need for big severe outbreaks. There will certainly be some thunder embedded within all the rain coming Middle America’s way, but not high risk days from the Storm Prediction Center.

Generally, there is usually a late year severe weather peak at the beginning of fall, as cold air really starts to come back to town. Unlike the spring severe season, cold air is denser and tends to completely supplant warm air. Cold air is reinforced, and warm air has a tougher time coming back, so the severe season is shorter than spring, where warm air keeps trying to bubble up.

Like the tropical season this year, we shouldn’t read to much into this quiet October. The hurricane season, like the fall severe season could still get very interesting very quickly.

Do you like surprises? I like surprises, so I am a fan of how this month turned out. WeatherNation, who very often gloms on to the Weather Service Forecast, found itself oscillating between the Weather Service, the Weather Channel and sometimes it’s own forecast, and managed to grab the Forecaster of the Month award for the month of July. Cagey strategy, and a big reward.

Outlet	Forecast Wins (year)
Weatherbug	6.33
Accuweather	5.99
The Weather Channel	4.83
National Weather Service	4.83
Victoria-Weather	3.99
WeatherNation	3.83
Forecast.io	2.16

We’ve made it all the way to August, and we haven’t awarded the FOTM to our June forecaster yet! That is a consequence of the active forecast and road trip schedule we’ve had of late, but now, certainly, is the time to give some meteorologists their due.

June was a mercifully slow start to the summer, with temperatures and storms more manageable than we’ve seen in recent years. July started to go off the rails, but we can appreciate Victoria-Weather’s victory for June with some sort of peace. Congrats to us!

Outlet	Forecast Wins (year)
Weatherbug	6.33
Accuweather	5.16
The Weather Channel	4.33
National Weather Service	4
Victoria-Weather	3.49
WeatherNation	2
Forecast.io	0.66

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 Niña 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.

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.

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 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!

Outlet	Forecast Wins (year)
National Weather Service	4
Accuweather	3.83
The Weather Channel	3.83
Weatherbug	3.33
Victoria-Weather	2.66
WeatherNation	2
Forecast.io	0.33

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!

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.