JANUARY 19TH-20TH STORM THREAT

First image is showing where the N energy is as well as the southern energy. As you can see our system is still way out over the Pac Ocean, the energy of which doesn't come ashore for about 36-48hrs or so. Notice where the N energy is located. It still has to journey even further N before rounding the N aspect of the TPV before beginning its journey into central Canada by hr 84 indicated by the yellow x's over the black line.



Next Id like to point out that we are still 4 days away and we currently still have changes occurring at H5 from model to model as well as within individual models meaning there is still plenty of time for a trend to cont both favorably as well as unfavorably. Below is simply the diff between 00z Euro and the most recent 12z. I will say three things. First, one run does not make a trend; however, the Ukie, while likely over correcting S&E might be onto something. Second, I do not believe that what I saw at H5 on the 12z Euro matches the surface at all so while we are seeing shifts at H5 you must take the surface with a large grain of salt as they often take time to catch onto the changes aloft. The third point I will make below, so look at the image comparisons Ive illustrated below until you come to my third point.










So my third point is that the changes aloft are a diff of only 12hrs in the timing/arrival of the N energy. IF we cont to see a mere 12 hr delay in the arrival of the N vort(esp this), and/or weaker S energy, and/or a further S track to the S energy; even the coastal plain COULD be in the game for moderate to significant snowfall, both front end and back end. Again one run does not make a trend, but there is some support from Ukie, and GEFS and there is still 4days away. I am not giving up just yet and you shouldn't either. The back end snow possibility for the coastal plain is real. As Rb has mentioned there is a very steep temp gradient such that if the wave of LP passes far enough S&E (likely needs to be S of LI somewhere) while we may start as snow and change to rain, if the phase is right and the track is right there could be a very quick burst of heavy snowfall on the back end.

Could it be a trend weaker with the PNA ridge might actually help us and be what we want?? It slows the speed of the northern vort into the conus; therefore, delays the phase for us. Syo/Jimmy I just read your last comment on the LR thread and I think your hitting the nail on the head.

@bobjohnsonforthehall wrote:How is Deep Thunder in terms of accuracy? Sounds impressive (and maybe a bit dirty) but haven't heard from it in a while. I ask because I hear that the Deep Thunder 12z buries NYC at 12-18 inches and is all snow.

It seemed to catch onto a few systems first last year. Id love to see it if someone has images to post. Hree is the EPS. 00z vs 12z

@Carvin wrote:https://www.facebook.com/groups/304744922905296/permalink/2083483801698057/ deep thunder

Perfect! Thank you.