The atmosphere had a convulsion at the end of April in the transition from winter to summer. The cold polar vortex in the stratosphere did not go gently into summer. Instead of fading slowly into a dome of warm air the whole atmosphere from the surface to the top of the stratosphere convulsed with wave energy driven upwards by an atmospheric dome over Scandinavia. Extraordinary atmospheric heating took place in the over the pole and cold air was pushed towards the temperate latitudes especially over the Pacific ocean. A dome of hot sinking air formed at very high levels over the Arctic pushing cold air and the jet stream south causing unseasonable storms to track across the Pacific ocean into California in mid May.
The European and American models agree on the main features — there will be severe storms beginning this weekend lasting for a week or more — but they have subtle differences in the timing and intensity of individual events. The most severe tornado outbreak is apparently going to begin on Monday or possibly Tuesday. However, severe weather outbreak forecasts aren’t reliable beyond 3 days or so, so expect modifications by local experts. Do not rely on anything I write here. This is written to give an early warning to people and because this is what climate change looks like. Consult your local NOAA weather forecasts to stay safe over the next week. The American model shows an extremely unstable situation developing late Monday over Texas and Oklahoma.
If the European and American models verify on this storm we may witness a tornado outbreak of historic proportions. However, it is also possible that there could be very bad severe weather and flooding without an historic outbreak of tornadoes. It’s too early to make an accurate forecast.
Update: European & American Models Agree on Monday
There has also been an update from NOAA’s Severe Weather Prediction Center. It’s low key because forecasts beyond 3 days are subject to error and revision but it is consistent with what I wrote yesterday. www.spc.noaa.gov/…
At this time there is high uncertainty about the number of tornadoes but the storms are likely to be slow moving and produce very heavy amounts of rain. The problem is that the jet stream is much more intense and further south than usual for mid-May and Gulf waters are very warm now, producing very wet unstable air masses. It’s a recipe for disaster.
End Update
The first round of severe weather will begin Friday in the southern plains. It isn’t expected to be as severe as the weather next week, but again, pay attention to your local forecast.
The outbreaks of severe weather may continue for ten days according to the American model. Obviously the accuracy of the model is not good ten days out, but this is a very large scale wave pattern so this forecast is worth posting to make the point that the severe weather could get as far north as Minnesota, Wisconsin and Michigan. There will be a very hot dome of air building over the southeast and it may persist. These heat domes can be very persistent once they get established.
Dr. Judah Cohen observed a week ago that there was an extreme stratospheric disruption that would cause wild winter weather if it happened in February. It’s becoming apparent that this will cause wild spring weather in May. I suspect it will be an historic outbreak of severe weather.
This isn’t your father’s atmosphere. The climate has changed. This is climate breakdown.
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Addendum
Please note I made an error in my diary 2 weeks ago about the heat dome over Greenland.
www.dailykos.com/…
According to Dutch DMI Scientists 2019 had the second earliest start to the melt season, not the first. I misinterpreted the NSIDC graph which has unusual ways of expressing deviance.
The melt season officially started a month early this year. In 2016 a very unusual weather pattern started melting in mid-April. polarportal.dk/...
Today DMI scientists announced the start of the Greenland melt season, the second earliest in a record that stretches back to 1980. “The start of the melt season occurs on the first of three consecutive days where more than 5% of the ice sheet has melt at the surface.” said scientist Peter Langen. “We use a pretty strict definition as we want to make sure it is a consistent start to melting and not just a blip due to unseasonal weather”. This year’s start of 30th April is second only to 2016, when a very unusual weather pattern caused a very early start to the melt season in mid-April.
“On average, the melt season starts around the 26th May, so we are almost a full month earlier this year” he continued.
Number three on the list is 2nd May 2010 when a similar weather pattern also caused early melt onset closely followed by 2017 on the 7th May, the top four have all occurred within the last ten years.
Note that the top 4 early melting years are all in the last decade. Spring is coming earlier to the Arctic and in many recent years it is happening in ways that disrupt normal northern hemispheric weather patterns with serious consequences to the lower 48 states.
All of this discussion ties to this technical paper published over 10 years ago that found that climate change causes “an atmospheric short circuit” an increased circulation from the weather layer (the troposphere) into the stratosphere, and back. acomstaff.acom.ucar.edu/...