February 12-13 Storm, Part III: Trilogy ends and then Obs thread soon!

[Minnesota Meso]

Been reading this thread and I'm fascinated about all the opinions out there.  Won't comment to much b/c of my location, so just a heads up. The RUC backup now has this in it's domain or just on approach. 

 

http://ruc.noaa.gov/RUC/Welcome.cgi

[Wonderdog]

How often in a setup like this does a SLP track inland. Usually, a Gulf storm or a Southeast storm tracks to around Hatteras and continues NE or follows the coastline, doesn't it?

[ravensrule]

With this forecast i do not understand how there is no warning up yet, but who really cares.

 

• Wednesday NightSnow. Low around 23. East wind 6 to 13 mph becoming north after midnight. Chance of precipitation is 100%. New snow accumulation of 3 to 5 inches possible.
• ThursdaySnow. High near 33. Breezy, with a north wind 15 to 20 mph, with gusts as high as 33 mph. Chance of precipitation is 100%.
• Thursday NightSnow likely before midnight. Mostly cloudy, with a low around 23. Northwest wind 9 to 17 mph. Chance of precipitation is 60%.

[ohleary]

do you just give it to them with the rest of your info?

 

Not really, the products are sent out by the CARCAH folks to the TOC (NWS Telecommunications Ops Center) who disseminate NWS products.  I see they are specifically sent to CMC, UKMet, Tokyo, Brasil, Argentina...and the WMO Global Telecommunications System who make them available as well.

[cng885]

Has anyone read the argument by wxsynopsis? 

 

Basically he is arguing the low is developing further south according to water vapor with stronger back flow.

 

https://www.facebook.com/WxSynopsis

 

Thoughts anyone?

[yoda]

1" QPF line went way west on 21z SREF out toward I-81 corridor...

 

[ravensrule]

Sorry if this was answered earlier, but is there a radio show tonight

There was supposed to be, but the banner is gone so i have no clue.

[mitchnick]

well, new SREF has the 0-850 line passing west of BWI for a few hours, definitely warmer than last run and the first time the 0 line came west of mby.....meh, it continues

[EasternUSWX]

Has anyone read the argument by wxsynopsis? 

 

Basically he is arguing the low is developing further south according to water vapor with stronger back flow.

 

https://www.facebook.com/WxSynopsis

 

Thoughts anyone?

 

Just weenie non sense. 

[mitchnick]

1" QPF line went way west on 21z SREF out toward I-81 corridor... image in a sec

yep, see my post re the 850 line

[PDIII]

How often in a setup like this does a SLP track inland. Usually, a Gulf storm or a Southeast storm tracks to around Hatteras and continues NE or follows the coastline, doesn't it?

No I think they track where ever... generally from west to east in our latitude but that is about all you can guarantee.. weather is generally chaotic 

[mitchnick]

if you run the precip maps through the end of the SREF run, you can see the CBB precip around the MA at the end of the run, so maybe the backside will overperform

[yoda]

well, new SREF has the 0-850 line passing west of BWI for a few hours, definitely warmer than last run and the first time the 0 line came west of mby.....meh, it continues

 

Um... 15z-21z THUR its like right at zero... maybe barely west of the I-95 corridor for a few hrs... but its not like its horrible +4 or something... more like +1 at most if that.  Before 15z THUR, 850 line is fine

[Kmlwx]

well, new SREF has the 0-850 line passing west of BWI for a few hours, definitely warmer than last run and the first time the 0 line came west of mby.....meh, it continues

It seems to be becoming higher confidence that we'll mix or even changeover for a while at least. I think a lot of eggs need to be in the front end stuff. We can still do really well before the 850s get unfavorable, I think. 

[mattmfm]

Concerns for I-95 at the moment I'd rate as dryslot > sleet > temp > ability to accumulate > rain. I think a 5-8" dump overnight seems like a good bet, teeter on the dryslot, and then 2-4" on backend CCB. Talk in this thread aside, dryslot really appears the biggest concern--and probably a flip to mist/light sleet dependent on its western advance. Even the NAM rips it northward to just east of the I-95 corridor. GFS (I think Wes flagged this during the afternoon), aside from it's odd QPF alignment, doesn't tug 850s down as you'd expect in a CCB. In fact GFS has dryslot bit further east than NAM, which is a half-decent sign.

 

Stay on the western edge and we'll rock, but otherwise probably shuts it off for a few hours. So 7-12" seems like a good consensus for now.

 

[nj2va]

Based on the mean spread of the SLP, there's likely a fair amount of members west of the mean.

Mean is 998 off Norfolk at 18z.

[mattmfm]

1" QPF line went way west on 21z SREF out toward I-81 corridor...

 

 

Huge boost of confidence--SREF QPF lag was one of my last remaining concern points. 

[stormtracker]

well, new SREF has the 0-850 line passing west of BWI for a few hours, definitely warmer than last run and the first time the 0 line came west of mby.....meh, it continues

Get the fork ready, we're about to be done. When I saw the inch line way west I kinda thought the 850s would follow.

[Kmlwx]

Based on the mean spread of the SLP, there's likely a fair amount of members west of the op.

Mean is 998 off Norfolk at 18z.

Is there really an "OP" though on the SREF? I thought it was just a collection of models - unlike the GFS where there's actually an OP run. 

[Ian]

if you run the precip maps through the end of the SREF run, you can see the CBB precip around the MA at the ed of the run, so maybe the backside will overperform

That happens a lot. My guess is the NaM starts giving in.

[Yeoman]

I get the sense LWX is too close to HQ etc. They have good mets but are among the worst offices when it comes to decisionmaking. I don't necessarily fault them for waiting but now that we are surrounded by warnings you'd think at the least they could hoist them in their high probability areas. They say low confidence but that's not what their numbers suggest when it comes to a warning at the least.

 

Most if not all of my non-enthusiast friends wouldn't have a clue what the difference is between a Winter Storm Watch and a Warning. This is more of a weenie gloating thing..

[dallen7908]

Is the 18Z NAM the operational for the SREFs? 

[DCAlexandria]

Based on the mean spread of the SLP, there's likely a fair amount of members west of the op.

Mean is 998 off Norfolk at 18z.

Hard to imagine we can go wrong with the branch mark.

[Ian]

Huge boost of confidence--SREF QPF lag was one of my last remaining concern points.

This ain't New England my friend.

[gymengineer]

Huge boost of confidence--SREF QPF lag was one of my last remaining concern points.

I agree. The precip bomb models all have a period of impressive snows before any potential changeover. That's much much better than what the GFS is showing.

[Sparky]

Justin Berk on fb made a bet with Tony Pann that Carroll County gets an official report of 12 or more inches.  Tony doesn't think that much will fall...lunches for bet.

[BTRWx]

Concerns for I-95 at the moment I'd rate as dryslot > sleet > temp > ability to accumulate > rain. I think a 5-8" dump overnight seems like a good bet, teeter on the dryslot, and then 2-4" on backend CCB. Talk in this thread aside, dryslot really appears the biggest concern--and probably a flip to mist/light sleet dependent on its western advance. Even the NAM rips it northward to just east of the I-95 corridor. GFS (I think Wes flagged this during the afternoon), aside from it's odd QPF alignment, doesn't tug 850s down as you'd expect in a CCB. In fact GFS has dryslot bit further east than NAM, which is a half-decent sign.

 

Stay on the western edge and we'll rock, but otherwise probably shuts it off for a few hours. So 7-12" seems like a good consensus for now.

 

nam_namer_045_700_rh_ht.gif

I like your analysis. I don't really remember much thunder-snow from 2010 unlike the potential of this system, but I might be wrong on that.

 

*my attempt at adding to the analysis

[nj2va]

Is there really an "OP" though on the SREF? I thought it was just a collection of models - unlike the GFS where there's actually an OP run.

No there is a mean though. I meant to say mean and not OP.

[Bob Chill]

DCA precip totals through 7am thurs. Most recent run of each model.

Rgem 1.3

Ggem 1.2

Nam .75

Euro .70

Gfs .52

I didn't check when the Canadians flip but I know those totals are not all snow

[gymengineer]

It seems to be becoming higher confidence that we'll mix or even changeover for a while at least. I think a lot of eggs need to be in the front end stuff. We can still do really well before the 850s get unfavorable, I think.

Once you're at peace with the changeover, then you want to root for a super wet solution. Even the 18z RGEM was an intense pre-mix dump.