Roidzilla Storm Mode - January 23, 2016 Updated Final Call

I can honestly say I did not expect to do this tonight. I am putting the forum - I think for the first time - under Roidzilla Storm Mode. I expect widespread 24" snow amounts to fall from southeastern PA - NJ - NYC - and LI.



The 500mb low closed off and is heading east-northeast. The ridge downstream is preventing it from moving north - which is why we're likely to see cut-offs in the first place. The trough is neutral with heights rising well into NJ / PA. It remains to be seen whether the trough goes negative at any point during this storm. At this time I think no. The decaying ridge will flatten heights and keep the flow progressive. But the block to the north, H5 closing off early, and favorably positioned jet streaks is what will keep the low close to the coast.



Here are 250mb winds valid 1pm tomorrow afternoon on a World map. Look at that Sub-Tropical Jet Stream! There is Pacific air feeding into this storm. There is also the northern jet phasing in with the STJ off the coast. THIS could be why some models are chasing convection on the east end of the trough.



It's not just the Pacific feeding the storm. There is also Caribbean moisture streaming up the coast. This is why current radar shows thunderstorms getting into the southeast and southern Mid-Atlantic. As these thunderstorms ride into the cold air mass, that will spark snow rates to intensify. Aka thundersnow!





The primary low is dying over western NC and a secondary is taking over off the coast of NC. Convection is streaming N-NW and H5 heights are pointing north. This argues for the surface low to take a track right up the coast. Once the ridge to the west collapses and the H250 jet streaks shift east, that is when the surface low will begin to pull away from the coast and track east. The timing of when this happens is critical for those near the gradient. If this happens quickly, the cut-off is real and areas just south will see a historic storm. If it takes time to develop, the surface low will track north enough to bring substantial banding into HV and CT.





The GFS (top) is elongated with 700mb vertical velocities, or where the greatest lift will be. Meanwhile, the NAM nicely pivots H7 VV's around the H7 low. The NAM - as well as other mesoscale models - keep the surface low organized and close to the coast while Globals broaden it out. Regardless, both models show incredible lift getting into the area in the early afternoon. The CCB is likely to be very impressive with thundersnow and snow rates of 2-3" an hour.

The NAM, RGEM, HRRR, RAP show Roidzilla-criteria snow falling over PARTS of the area.

UPDATED SNOW MAP



AGAIN, this means my confidence is HIGH that the POTENTIAL for 24" is possible if you're in the purple or red shading!!

Wow what a gradient u have frank 10 miles south of me up to 24. Hey it will b what it will I'm still stoked. Lol news 12 5 to 9 max.

SoulSingMG wrote:UPTON!!!!!!!!!!!!

the 18 to 24 nws literally ends about 3 miles north of me wow.

SoulSingMG wrote:UPTON!!!!!!!!!!!!

Orange county solidly in 8-12 on that map and still only a winter storm watch.

I suppose the thinking is if that ridge in the west collapses to soon as is still very much on the table as frank has mentioned the HV is scrooed.

I will not sleep well tonight.

Omg news12 is terrible new update 5 to 9 inches. I can't believe no state of emergency.

snow247 wrote:

CPcantmeasuresnow wrote:

SoulSingMG wrote:UPTON!!!!!!!!!!!!

Orange county solidly in 8-12 on that map and still only a winter storm watch.

I suppose the thinking is if that ridge in the west collapses to soon as is still very much on the table as frank has mentioned the HV is scrooed.

I will not sleep well tonight.

A lot of people are saying this could come even further north.

give me 20 miles I to the 18 to 24 I'll b even happier. Dr k in hand this is the best.

algae888 wrote:jman blizzard warning for mt Vernon just came over my phone!!!!!!!!

we in same county wth? Weird not shown on nws map. What carrier do u have? T-Mobile not gr8. That's what I have.

Orange = blizzard warning

Al it changed on map. Still coming through. Not in txt yet. Here we go!