the cause of the polar vortex is the difference in temperatures between the poles and the equator. the vortex has been unable to form this year due to the difference not ramping up as it usually does when the polar night takes effect, due to the dramatically increased greenhouse effect trapping heat into the upper atmosphere. this inability for the vortex to strengthen has led to some "polar air" falling south, but that "polar air" is not very cold due to the increased greenhouse effect. it is not reducing temperatures here substantively.

the out of date models, which have not been updated to adjust for the reality of an already substantively altered climate, are continuing to rely on out of date science to make projections. they can be expected to consistently be wrong by a factor and that factor will continue to increase until they update it to account for the already warmed planet. in fact, that factor will increase exponentially.

the polar models are not accounting for an increased greenhouse effect being particularly and increasingly strong at the poles. for that reason, they will continue to exaggerate the effect of polar vortex weakening and continue to overshoot cold snaps. the clickbait weather forecasters will not make adjustments and will instead continue to profit off of disseminating mass ignorance.

there is a very short remaining time window for a vortex to form before the sun returns and it will continue to rely on the size of temperature differences between the equator and the poles.  

there was a last minute change n the forecast to suggest the possibility of frost here this weekend, but they revised it back to above freezing at the last second and it doesn't look like the actual reading is going to get much lower than 3 or 4 C.

it's very late in the season here to have avoided even a single frost overnight and the temperature really hasn't even undergone it's yearly crash yet. we have had a few moderately cool dips but we have not seen sustained daytime highs below 15 C yet.