Tornadoes
If you are looking at this you may realise it's very out of date! I will be finding time to update it, so check back over the next few days - 13/04/2021
Potential Severe Weather Episodes - 10/03/2021
The first multi-day severe weather event of 2021 is expected as we got closer and closer to the heart of tornado season. The SPC has a slight risk across parts of the Central U.S. today, with a 5% tornado chance across Iowa, Minnesota and Wisconsin.
The threat for tornadoes is greater further north where a few tornadoes are possible. CAPE of 1000-2000j/kg is being modelled on the HRRR, as well as decent low level shear. Hodographs show nice low level curvature as well as good ventilation of the anvil level winds. Fast storm motion parallel to the boundary should help keep things discrete before storms start to turn into a line. There is clearing and destabilisation already evident on satellite, so things do seem to be going to 'plan', but still time for this to change.
One of the concerns was lack of moisture, but surface dew points have already exceeded 60F in places, and more is expected, so in summary, a couple of tornadoes are possible across the N Midwest today. I wouldn't completely rule out a strong tornado as well - you never know.
Slight Risk of Tornadoes today - 28/02/2021
2021 has got off to quite a slow start in terms of tornadoes, though we have had quite a few strong ones - Damascus GA, Brunswick NC, Fultondale AL. However we do have another tornado risk on our hands today, though not a big one.
5% tornado probabilities within 25 miles of a point. The SPC mentions the chance for a couple tornadoes associated with an MCS that is expected through the slight risk area. The environment isn't all that bad - good shear, some good instability as well, it's just the general setup doesn't support discrete long-lived supercells, rather an MCS.
The HRRR does support a few discrete cells ahead of the MCS, but they are quite small and there isn't great model to model consistency, but could be something to watch.
Tornado Threats this Week - 15/02/2021
This is all due to a very active jet stream driving troughs through parts of the US. It's the shortwave troughs that form around the base of the main troughs that cause most of the severe weather.
Today's threat is largely conditional, but does have the potential to spawn a few tornadoes across parts of Florida and Georgia. There is a very strong low-level jet expected over parts of Dixie Alley this evening, and this will be causing a highly sheared environment, and so any organised storm has the potential to produce a tornado, possibly even a strong one. Later this week, we have another severe weather threat. There is less to say about this one as it is further away, but a few tornadoes as well as strong straight-line winds look possible.