Feb 1/2 Obs

[Bob Chill]

we'd still get a snowstorm with that track...not all snow, but we'd get accumulating snow

Absolutely. Just not a "perfect" one. Expectations after the euro and 2 gfs runs are high. And they should be but not without caution. We're still 72 hours out.

[packbacker]

There was a cluster of euro members with slp in n wva and 18z gefs has it as well. It's something to be wary of.

Navgem and jma also take the low from wv to overhead. Yes, those aren't models we typically take into consideration but if something is going to go wrong, a nw track would be problem from what I'm seeing.

 

I counted 4/21 that tracked the low over you or NW of you, similar to this member below.  But there was also 3 or so that tracked them in s-NC, which jackpot c-VA,  but majority were great tracks for you guys.  Hold it steady for the next few days.

[Deck Pic]

18z GFS breakdown for DCA plus surface temp at end of each 3 hours...7am on Tuesday morning is -1

 

1pm - 4pm - T - 35

4pm - 7pm - 0.04" - 32

7pm - 10pm - 0.04" - 31

10pm - 1am - 0.15" - 31

1am - 4am - 0.32" - 30

4am - 7am - 0.16" - 23

7am - 10am - 0.08" - 20

10am - 1pm - 0.04" - 19

[Bob Chill]

I counted 4/21 that tracked the low over you or NW of you, similar to this member below. But there was also 3 or so that tracked them in s-NC, which jackpot c-VA, but majority were great tracks for you guys. Hold it steady for the next few days.

Thankfully we're at the range where ops can be used with some skill. Just like you guys, we worry a lot here because fails come too easy at times. I don't want to see any notable nw trend with 0z ops.

[BTRWx]

Thankfully we're at the range where ops can be used with some skill. Just like you guys, we worry a lot here because fails come too easy at times. I don't want to see any notable nw trend with 0z ops.

You should have a colored tag.

[mitchnick]

Yeah, 87 hour SREF and all, but that 850mb zero line is cutting it really close.

but if you run a loop you can see that the 0-line reached its max northerly progression at 84 hours. and then started backing down at 87

[MN Transplant]

but if you run a loop you can see that the 0-line reached its max northerly progression at 84 hours. and then started backing down at 87

 

The 18z GFS was obviously all snow, but the morning sounding did show that the 850 level was the max.  So, there wasn't anything sneaky.

[Amped]

The things keeping it from being a cutter are the strong vortex in Canada and the strong westerly pacjet behind it.    It can still go far enough north to screw us though.

[mitchnick]

Thankfully we're at the range where ops can be used with some skill. Just like you guys, we worry a lot here because fails come too easy at times. I don't want to see any notable nw trend with 0z ops.

This year, the vorts have trended SE but I don't know if we're in a new regime after the bliz reset the stage so to speak.

Frankly, I worry just as much about suppression as northerly track so I don't know which side of my mouth to take my Valiums.   lol

I will say that, at least with the old GFS, it always seemed to model the 50/50 too strong days out and that was the usual explanation for the last minute shifts north.

Hopefully, that doesn't happen this time, especially since all the medium range models, save the NAVGEM/JMA, are in unusual agreement at T-72 hrs.

[mitchnick]

The things keeping it from being a cutter are the strong vortex in Canada and the strong westerly pacjet behind it.    It can still go far enough north to screw us though.

yep, and that is reflected in the PNA graph that the ensembles were dropping to 0 the other day when modeling was favoring a northerly track

now, although the PNA is modeled to drop a bit, it stays clearly positive

ftp://ftp.cdc.noaa.gov/Public/gbates/reforecast2/teleconn/4panel.png

[bigjohndc]

Hopefully this is an acceptable meterological question.

Is there a resource (or someone on here) that can explain why last Monday's storm phased, creating the second coastal low. As compared to upcoming Super Bowl storm that will stay intact and track east?

[WxMan1]

but if you run a loop you can see that the 0-line reached its max northerly progression at 84 hours. and then started backing down at 87

 

Often times when the 850 0 is that close, there ends up being a +0.5 somewhere farther up, generally between 800-750 mb.  Obviously the soundings would tell the whole story.  But again, just from a conceptual, climatological standpoint, we want to be closer to the -3 to -6C range at 850 rather than flirting with the 0C.  Because when we get that close, even if we're not mixing (yet), typically the max dendritic growth zone is displaced farther to the north, meaning it can still be snowing ("yay"), but juts not with the best rates ("boo").  I still think DCA and points along/north of I-66 and Rte 50 can get a nice thump, but I would wager that the best rates and total snowfall accumulation are going to be along and north of 70.  At least taking a consensus with the current operational runs.

 

Would like to see the SLP and 850-700 thermals drop south another 50 or so miles. 

[Deck Pic]

The 18z GFS was obviously all snow, but the morning sounding did show that the 850 level was the max.  So, there wasn't anything sneaky.

 

84 hours was the riskiest sounding and the warm nose is still around -1.5...850mb is -3

 

[Bob Chill]

You should have a colored tag.

Yea, a pink one if you remember those. Lol

I never even looked at a weather model until 2006 and learned everything from Wes, HM, Matt, Ian and a bunch of other regulars on the board. And my only niche is snow in my backyard. Weird hobby but fun nonetheless.

[mitchnick]

Often times when the 850 0 is that close, there ends up being a +0.5 somewhere farther up, generally between 800-750 mb.  Obviously the soundings would tell the whole story.  But again, just from a conceptual, climatological standpoint, we want to be closer to the -3 to -6C range at 850 rather than flirting with the 0C.  Because when we get that close, typically the max dendritic growth zone is displaced farther to the north.  I still think DCA and points along/north of I-66 and Rte 50 can get a nice thump, but I would wager that the best rates and total snowfall accumulation are going to be along and north of 70.  At least taking a consensus with the current operational runs.

 

Would like to see the SLP and 850-700 thermals drop south another 50 or so miles. 

agree, but since it's the srefs we really can't get a "sounding" per se

wrt the srefs, they look darn good to me and, taken with all the other guidance, reflect the best chance we've had all year for a mod/major event....and that's all we can hope for now

[Bob Chill]

Great post WxMan1. It's the precise reason why we see the the parrs-parkton jackpot over and over. Nothing to do with luck and everything to do with location and climo. Elevation never hurts when there's ne-e surface winds either.

[ravensrule]

Yea, a pink one if you remember those. Lol

I never even looked at a weather model until 2006 and learned everything from Wes, HM, Matt, Ian and a bunch of other regulars on the board. And my only niche is snow in my backyard. Weird hobby but fun nonetheless.

You are one smart and patient student then. You and Matt know as much as a pro met.

[Deck Pic]

You are one smart and patient student then. You and Matt know as much as a pro met.

 

thanks, but no dude...I just like snow

[WxMan1]

84 hours was the riskiest sounding and the warm nose is still around -1.5...850mb is -3

 

84.png

 

This is encouraging...just look at that relatively deep layer between -10 and -20.  While not isothermal...it's still pretty damn deep! Good for dendrites!

 

BobChill -- Agreed!

[Bob Chill]

You are one smart and patient student then. You and Matt know as much as a pro met.

Just a weird quirk Tbh. I studied hard during my years in the Rockies because snow setups are basically range specific. Since I was addicted to powder skiing I spent a lot of time understanding exactly what to look for to get good snow in my specific county. I was really good at it. It's no different with my yard here. Unfortunately much less prolific. Haha

Eta: what matt said. I'm a one trick pony in small region. It really is silly but fun.

[ravensrule]

thanks, but no dude...I just like snow

Don't want to argue but I would put your knowledge up there with most mets. Either way it is damn impressive.

[usedtobe]

This is encouraging...just look at that relatively deep layer between -10 and -20.  While not isothermal...it's still pretty damn deep! Good for dendrites!

 

BobChill -- Agreed!

The sounding is a good one but there still is enough uncertainty about the track to make me nervous.   

[ravensrule]

Just a weird quirk Tbh. I studied hard during my years in the Rockies because snow setups are basically range specific. Since I was addicted to powder skiing I spent a lot of time understanding exactly what to look for to get good snow in my specific county. I was really good at it. It's no different with my yard here. Unfortunately much less prolific. Haha

I wish i was as patient as you to learn everything but my bad ADD prevents it. Plus with my crazy sports following, work and 5 kids I would probably be divorced if i lasered everything like you. On to the Nam and ill put any further banter in one of the 12 threads.

[Deck Pic]

The sounding is a good one but there still is enough uncertainty about the track to make me nervous.   

 

we could easily mix..though I sort of expect the 0z models to nudge south

[WxMan1]

The sounding is a good one but there still is enough uncertainty about the track to make me nervous.   

 

Absolutely Wes...especially for us east of the fall line and along/south of Rte. 50..

[usedtobe]

we could easily mix..though I sort of expect the 0z models to nudge south

I like wiggle room because of where I live.  Even with a non perfect track we see accumulating snow, it's just how much. 

[mitchnick]

I note NAM is .9C colder at 850 Sat. evening at BWI vs. 12Z

small and insignificant? idk, but I'd rather see it colder than warmer

[ers-wxman1]

This is a critical run. If it stays impressive...we could be looking at headlines tomorrow.

[MN Transplant]

Looks a little north with the vort out west, but that doesn't necessarily mean anything.

[WxMan1]

we could easily mix..though I sort of expect the 0z models to nudge south

 

Any bit would help.  50 miles would be nice.  This is more of a BL issue, but there is pretty good snowpack to our northeast. We could see better low level northerly ageos flow and CAD signature than the models are hinting at.