Storms will blossom very quickly in the Upper Midwest

There is an enhanced risk for severe weather today in Minnesota, though at present, the radar is pretty sparse, save for a few showers in northern Minnesota and the first severe storm in northwest Iowa.

This radar imagery is from about 4:15. Here is a look at the HRRR forecast radar for about 630 this evening.

It looks as though the guidance is a little behind schedule, but the most important thing to note, will be how fast this line develops. This is the forecast radar 45 minutes later, or 715.

This looks like a strong line from Mankato to Storm Lake. Note the distinct blobs within the line. The threat for tornadoes and large hail is real tonight, and it is evidenced by the depiction of discrete cells within this line.

Eventually, and only within another 45 minutes, the storm will metastasize into a line. It will still be strong, and straight line winds will be added to the mix of threats.

This is the epitome of the “pay attention to the skies” days in southeast Minnesota and northern Iowa. Strong, dangerous storms are likely tonight, and they are likely to develop rapidly. It is possible that strong storms can develop and produce tornadoes even between radar scans with rapid development such as this.

Stay alert, heed local warnings, and listen to your gut. If it seems dangerous, take shelter, even if a warning has not yet been issued.

*Even as I was writing this, a tornado watch was issued for the region*

Imelda stalks where Harvey still haunts

Meteorologists everywhere feel a twinge of guilt and pain every time severe weather targets life and property. We all love the weather, but when it turns ugly, it hurts a little differently, like we have somehow been betrayed. It’s worse when the bad weather is somewhat unanticipated.

Imelda was never anticipated to be a strong storm, in terms of central pressure, or wind speed, and it wasn’t anticipated, originally, to linger very long. Eventually, the storm did slow down and tracked over the same tract of land for about 48 hours. The result is images that resemble those from Hurricane Harvey, particularly between Houston and Beaumont.

Here is a look at the heaviest rain of the past 24 hours. There is a swath from the Woodlands in the east Houston metro to Beaumont that saw 10+ inches of rain today. Over the course of the storm, that same area saw close to 2 feet.

I’ve underlined Houston and Beaumont on the map which should show you something else from a couple of different perspectives. Either you will see this map, depending on your perspective. Either you will note that the is a lot of rain for a very large area, or you will note that this is actually a lot less rain than the area saw with Harvey. Both conclusions are true, and should be telling.

Even though there is quantitatively less rain from Imelda, there was a lot of rain for a very large area IT was disruptive, deadly, destructive and evocative of the all time crisis that Harvey brought. This should underscore just what a nightmare Harvey was, but also sound an alarm about the eminent threat of any tropical feature. Just because Imelda’s torrential rain affected a smaller footprint doesn’t mean it wasn’t a major catastrophe. Imelda didn’t bring 5 feet o rain, but 2 is still pretty overwhelming.

The Appalachians and the heat

Usually, when you think of mountains, you think of snow capped peaks and chilly air. In Greensboro last week, they were directly responsible for temperatures not cooling off as quickly as it could have. cold air was rushing south from the Great Lakes, but got hung up in the mountains. Southerly flow with humid air produced clouds and a bit of rain that certainly allowed for a cooldown, but not quite on the order forecast by our model guidance for Friday. Weatherbug had a blend of a good temperature forecast, and were one of only three that had rain in the forecast on Thursday.
Actuals: Thursday – .01 inches of rain, High 95, Low 72
Friday – .01 inches of rain, High 82, Low 72

Grade: A-C

August forecaster of the Month (and a recap of the nasty weather in South Dakota)

Before we begin, I want to highlight just what a miserable several days it’s been in southeastern South Dakota. Three EF-2 tornadoes embedded in a strong squall line tore through the south side of Sioux Falls, the state’s largest city Tuesday night. The massive devastation goes to prove, once again, that these strong squall events should be taken very seriously, because these tornadoes were so quick and briefly on the ground, they were over almost as soon as they were detected on radar.

The heaviest damage seemed to occur in one of the main commercial areas of the city, passing through a shopping center and a mall parking lot, and most noticeably tearing to shreds an Advanced Auto Parts. The City of Sioux Falls added this drone footage to their Twitter feed.

While the tornadoes were embedded in a squall line, the squall line was a part of a persistent pattern of wet weather, that brought massive flooding to southeastern South Dakota and southwest Minnesota. Large tracts of I-90 were closed west of Sioux Falls to Mitchell, and many towns, including Madison, were cut off from the outside world by the rising rivers and creeks in the area. Many places received a foot of rain in a 72 hour period, and the region will remain wet this week. Let’s hope for better days soon.

As for the forecasting in the month of October, WeatherNation’s strategy of associating closely with the Weather Service and changing course only when necessary really only works if you find those situations where you can add value on your own. Well, in August, they did. Not only did WeatherNation win the forecasting title, the NWS dropped all the way to third. Congrats to WeatherNation. (Charts below are for daily forecasts)

OutletMonth wins
National Weather Service1.5
The Weather Channel1
OutletMonth winsyear wins
The Weather Channel111.7
National Weather Service1.57.28

It’s all the same

We took a look at the central Valley in California early last week, and it was a pretty tough verification. Not, perhaps, in the way you think. Fresno wasn’t going to see much weather, and it’s position on the west coast led the lot of us forecasters to rely heavily on model guidance. As a result, there was a FIVE way tie at top of the leaderboard, and the other two outlets, The Weather Channel and Weatherbug were only a degree behind. The trend was for a cooler Tuesday than models indicated, so the forecasts were consistent, they were consistently too warm.
Actuals: Monday High 102, Low 72
Tuesday – High 99, Low 70

Grade: B

Greensboro, North Carolina

The Carolinas were clipped by Dorian, with coastal sections of the states from Charleston to the Outer Banks sustaining damage, primarly due to storm surge and some isolated tornadoes, like the one in North Myrtle Beach. Greensboro was largely unaffected, and now can look instead to the west for their upcoming weather.

At 1152AM, ET, Greensboro was reporting a temperature of 79 degrees with fair skies. There was a little bit of cloud cover across the region, but not so much that the satellite was very busy. A stalled boundary suspended between two areas of low pressure in the Great Lakes was inducing a generally southerly flow, which will likely lead to low clouds and fog when temperatures start to wane.
The western low will start to occlude, while the cold front attached to the boundary to the east will begin to sink further south, decoupling from the western low. There won’t be much energy with the tail of this front as it passes into North Carolina, but after sunset, destabilization aloft might lead to a few showers and storms on Friday evening.
Tomorrow – Sunny and humid, High 92, Low 73
Friday – Mostly cloudy with increasing chances of rain. Cooler, High 83, Low 71

TWC: Tomorrow – Except for a few afternoon clouds, mainly sunny. high 95, Low 72
Friday – Scattered thunderstorms High 81, Low 71

AW: Tomorrow – Mostly sunny, hot, High 94, Low 71
Friday – Intervals of clouds and sun, a couple of showers and a thunderstorm, mainly later; warm High 83, low 72

NWS: Tomorrow – A slight chance of showers and thunderstorms after 2pm. Patchy fog before 9am. Otherwise, sunny,  High 94, Low 71
Friday – A chance of showers and thunderstorms, mainly after 1pm. Increasing clouds, High 86, Low 70

WB: Tomorrow – Sunny. Patchy fog in the morning. A slight chance of showers and thunderstorms in the afternoon. High 93, Low 73
Friday – Partly sunny. A chance of showers and thunderstorms in the afternoon, High 83, Low 73

WN: Tomorrow – Partly cloudy with isolated storms, High 94, low 72
Friday – Partly cloudy with scattered storms, High 86, Low 70

FIO: Tomorrow – Humid and mostly cloudy throughout the day. High 93, Low 70
Friday – Humid and partly cloudy throughout the day. High 84, low 70

Model guidance suggests that temperatures will actually be in the high 70s on Friday, but note how nobody is on board with that. This is because guidance often fails to cope with terrain’s influence on temperature. That heavy, cold air will struggle to clear Appalachia, and with a blanket of mid level clouds, radiative cooling will be unlikely. Here is the satellite, with no clouds to speak of this morning.

Dorian devastates Bahamas, batters East Coast

By now, we’ve all heard the stories of utter devastation for the northern Bahamian islands of Great Abaco and Grand Bahama. The initial storm surge put a lot of Abaco underwater at the initial landfall, and many deaths on the island were the result of drowning during the storm surge, while in this case, the eye’s passage overhead provided a chance for many to get to higher, safer ground.

The storm then sat and spun over the eastern side of Grand Bahama, cutting the largest city, Freeport, off from the rest of the island. The destruction there, thanks to persistent triple digit wind speeds and a very high storm surge, is comprehensive.

Dorian’s slow down fortunately spared the Floridian coast from the worst damage, but the storm spiraled northwards and pummeled Georgia and the Carolinas with rain, storm surge, tornadoes and category 2-3 winds, before it made a brief trek over the Outer Banks, with a landfall at Cape Hatteras. Take a look at the radar imagery to see how close the eye was to Charleston and Wilmington at various points.

Dorian moved away from the Carolina coast and as he weakened, broadened his footprint, meaning more rain and cloud cover further from the center of the storm. A course directly up the Gulf Stream and away from land will allow for maintained intensity until he made another landfall, this time over the weekend in the Canadian Maritimes.

Dorian tracked directly over Halifax, Nova Scotia with hurricane strength winds, and thought it didn’t approach the intensity it had when the storm swept through the Bahamas, he did considerable damage there as well.

The above video provides a good recap of the storms entire course. At least 45 people are confirmed to have died in Dorian’s path, with the majority of the fatalities in the Bahamas, though many more are possible when the affected islands are accessible.

If you can help out and choose to do so, the Red Cross is always accepting donations.

Fresno, California

All eyes remain on Dorian as he batters the northern Bahamas, and we can openly speculate on his further track. It appears as though his course will mean a greater threat for the Carolinas than Florida. Last year, California bore the brunt of weather headlines for much of the year, thanks to drought and fires. This year, California is mercifully off the radar. Let’s check back in.

At 953PM, PT, Fresno was reporting fair skies and a temperature of 87 degrees. While not humid, the dew point was certainly a bit warmer than normal for central California. Despite that, the Golden State was clear, though the monsoon was active with heavy storms over Arizona.
Monsoonal activity will diminish tomorrow, though some high peak showers and storms will be possible, but settled into the valley, a little bit of morning haze will burn off quickly, with hot sunny skies in the afternoons.
Tomorrow – Sunny and hot, High 102, Low 72
Tuesday – Sunny and hot High 102, Low 74

TWC – Mostly sunny skies. High 103, Low 73
Tuesday – Mainly sunny. High 102, Low 73

AW: Tomorrow – Mostly sunny; hot High 103, Low 73
Tuesday – Mostly sunny; hot High 102, Low 72

NWS: Tomorrow – Sunny and hot, High 100, Low 73
Tuesday – Sunny and hot, High 100, Low 73

WB: Tomorrow – Sunny, High 102, Low 74
Tuesday – Sunny, High 101, Low 74

WN: Tomorrow – Sunny, High 100, Low 73
Tuesday – Sunny, High 100, Low 73

FIO: Tomorrow – Partly cloudy throughout the day. High 103, Low 71
Tuesday – Clear throughout the day. High 103, Low 71

The forecast is quite warm, but it’s interesting that the Weather Service is the coolest outlook. That’s not how it usually goes. Chec out this crystal clear satellite.


The forecast in Monroe seemed promising. There was a little bit of rain in the early part of Wednesday, but then the heat was supposed to break. It certainly did not. Instead, high temperatures remained in the mid 90s, which was just as hot as it was before a weak cold front slid through. The National Weather Service and Weathernation weren’t optimistic about a cool down, and ended up claiming a forecast victory.
Actuals: Wednesday – Thunderstorms reported, not measured, High 95, Low 72
Thursday – High 95, Low 70

Grade: C