Friday, January 21st Storm Discussion

[capecod04]

Are we looking at a Thursday night start or Friday morning start?

[Mr Torchey]

Looks a lot like the nam and euro to me, nice consensus on a region wide 2-6 inches of powder, less nw a little more se should be a nice mantle on top of the ice setting the stage for a frigid weekend.

[Zeus]

Are we looking at a Thursday night start or Friday morning start?

Yes.

[Damage In Tolland]

Are we looking at a Thursday night start or Friday morning start?

3:00-5:00 am start time from sw to NE

[CoastalWx]

You're not going to get much snow if you can't even close off an 850 circulation. I'd still give it a chance for something more interesting, given we're 48 hrs out. As it is now, the GFS would imply some dam good ratios.

[Kbosch]

It's not much but with that good fluffability it's a nice advisory event. We have time, especially this winter, to work things out further.

[weatherwiz]

The differences at H5 between the NAM/GFS are pretty crazy.

[CoastalWx]

I think the one interesting thing that I like, is the band of snow that shoots out way to the northeast, due to mid level frontogenesis. Notice how far the mid levels are saturated by 06z to 12z Friday....right into sne. This may promote a band of fluff, before the main stuff develops from the CCB.

[ORH_wxman]

You're not going to get much snow if you can't even close off an 850 circulation. I'd still give it a chance for something more interesting, given we're 48 hrs out. As it is now, the GFS would imply some dam good ratios.

Its basically an advisory type event produced via isentropic upglide....there's no real CCB or anything similar that ever develops in time for us. At least we may have some good ratios on our side, but the look at 500mb is not very encouraging for those trying to get a bigger event out of this.

Hopefully we'll see it trend back a bit deeper and get the vortmax underneath us, but its going the wrong direction right now, not the correct one which is a problem this close in.

[Typhoon Tip]

The problem with this Friday deal is that a potential rapid cyclogenesis that clips middle and eastern areas has a very small tolerance for error. The models et al are playing too many games with vort field intensities, as well as discrete jet stream interactions between the north and south flows. The 06z vort max that cuts over or just south of the area is about 10-15 whole units stronger then the 12z, and it is hard to see where the variance comes from as all the contributing players are in the denser sounding grid - so why would it lose? (rhetorical question).

It wouldn't shock me if some run like 18z or 00z tonight, or 06z tomorrow morning, suddenly flashed back on the NAM and the FRH data grids back on in with over 1" liq equiv all the sudden, just as much as it wouldn't shock me if it didn't. There really isn't any way to correct for uncertainties in this type of situation, because it is beta-meso scales where dynamical interactions will dictate how that all evolves, which is not really well teleconnector driven for starters. That said, the back-ground +PNA is the best thing going because with the NAO rising and positive, that does tend to raise SE heights and narrows said range for error on this deal.

[weatherwiz]

Definitely going to come down from my widespread 6-12'' thinking...when things begin to look less encouraging as you get closer rather than becoming more encouraging that should be a red flag. Luckily we'll have good ratios which will get us to the advisory levels.

[Mr. Windcredible!]

Still thinking this is a light-mod event for most. Advisories...maybe low-end warning criteria in some lucky spots. I'll take it though...will just be nice to get some fresh powder on what's left of my snow pack down here.

[Damage In Tolland]

Definitely going to come down from my widespread 6-12'' thinking...when things begin to look less encouraging as you get closer rather than becoming more encouraging that should be a red flag. Luckily we'll have good ratios which will get us to the advisory levels.

I wouldn't if I were you. 00z runs tonight are gonna make this a much bigger deal. Watch..and wait

[OKpowdah]

if we dont start seeing a deeper low extending further into the mid levels on the 12z gefs, euro, cmc, etc. I'm throwing in the towel on 12+

[weatherwiz]

I wouldn't if I were you. 00z runs tonight are gonna make this a much bigger deal. Watch..and wait

I'm just not sure if that is going to happen or not, with the 12z runs I was hoping to see at least one of the models show more digging of the northern stream but that did not happen at all, if anything the northern stream looks even less impressive than past runs as far as the digging goes. It doesn't appear either that there will be much southern stream interaction either, so this will be predominately northern stream. Luckily though the main s/w in the northern stream does seem to intensify over our region and does become negatively tilted.

However, I think the strongest lift might end up being to the north and west our our locations. The RH fields though do look very moist so it shouldn't take much lift to generate snow but nothing is really looking positive for a moderate to major event.

[Ginx snewx]

Screw the positive NAO sorry NNE guys, looking forward to slow deep systems soon. See ya

[Damage In Tolland]

I'm just not sure if that is going to happen or not, with the 12z runs I was hoping to see at least one of the models show more digging of the northern stream but that did not happen at all, if anything the northern stream looks even less impressive than past runs as far as the digging goes. It doesn't appear either that there will be much southern stream interaction either, so this will be predominately northern stream. Luckily though the main s/w in the northern stream does seem to intensify over our region and does become negatively tilted.

However, I think the strongest lift might end up being to the north and west our our locations. The RH fields though do look very moist so it shouldn't take much lift to generate snow but nothing is really looking positive for a moderate to major event.

You've seen 2 runs from the garbage US models..You haven't seen any 12z ensembles or any foreign guidance

[mahk_webstah]

I don't see any updated blog for Joe L.

[OSUmetstud]

The problem with this Friday deal is that a potential rapid cyclogenesis that clips middle and eastern areas has a very small tolerance for error. The models et al are playing too many games with vort field intensities, as well as discrete jet stream interactions between the north and south flows. The 06z vort max that cuts over or just south of the area is about 10-15 whole units stronger then the 12z, and it is hard to see where the variance comes from as all the contributing players are in the denser sounding grid - so why would it lose? (rhetorical question).

It wouldn't shock me if some run like 18z or 00z tonight, or 06z tomorrow morning, suddenly flashed back on the NAM and the FRH data grids back on in with over 1" liq equiv all the sudden, just as much as it wouldn't shock me if it didn't. There really isn't any way to correct for uncertainties in this type of situation, because it is beta-meso scales where dynamical interactions will dictate how that all evolves, which is not really well teleconnector driven for starters. That said, the back-ground +PNA is the best thing going because with the NAO rising and positive, that does tend to raise SE heights and narrows said range for error on this deal.

John, the CPC teleconnectors show the NAO is slightly positive and falling negative. It does appear to be a central or east based -NAO though. You can see a big ridge in the central Atlantic at 60 hours with a 564 dm height line east of Greenland. I don't know if that changes your thinking on this event, however.

[Baroclinic Zone]

So far the 12z runs are very disappointing.

?

For what, your MECS?

I see nothing wrong with what the NAM/GFS are showing.

[ORH_wxman]

12z Ukie looks quite similar to the GFS.

[Boston-winter08]

12z Ukie looks quite similar to the GFS.

ya i was just going to post on it, doesn't it show 2-4 exluding the 6hr frame with the most QPF?

[ORH_wxman]

12z ukie looks not too bad, though we're missing the critical 6-hr frame

2-4 not including the potential best frame (probably another 3-6)....i would guess 5-10 on the crazy uncle as a whole

???

It shows 0.10"-0.15" of qpf for 42-48h...at most we'd see another 0.20-0.25" with that track, except perhaps a tad more on the Cape.

It looked almost identical to the GFS at 48h. I see a 2-5" solution on the Ukie...maybe a smidge more far SE areas like Cape.

[weatherwiz]

You've seen 2 runs from the garbage US models..You haven't seen any 12z ensembles or any foreign guidance

Instead of thinking widespread 6-12'' I'd go with widespread 3-7'' with the highest totals occurring up across E MA and the lesser totals occurring across western/southwestern CT.

[OKpowdah]

?

For what, your MECS?

I see nothing wrong with what the NAM/GFS are showing.

ok

[Boston-winter08]

???

It shows 0.10"-0.15" of qpf for 42-48h...at most we'd see another 0.20-0.25" with that track, except perhaps a tad more on the Cape.

It looked almost identical to the GFS at 48h. I see a 2-5" solution on the Ukie...maybe a smidge more far SE areas like Cape.

oh, maybe you're site's resolution is better than the one I use...

http://weather.uwyo.edu/cgi-bin/model?MODEL=ukmet&TIME=2011011912&REGION=USLCC&FCST=all&LEVEL=0&F2=none&C1=hght&C2=tmpc&VEC=none&F1=p06i

[Kbosch]

There is a big disconnect here from those expecting something large and others expecting an advisory event. I expect the latter and have for the entire time but naturally want more.

For example, this is fine for me from the 12z NAM...not much precip to work with but good ratios, AWT.

110121/0600Z  42  11004KT  27.5F  SNOW    12:1| 0.1|| 0.1    0.012|| 0.01     0.00|| 0.00    0.00|| 0.00   100|  0|  0
----------------------------------------------+----++-------------++--------------++-------------++-----------+---+---
110121/0700Z  43  10004KT  27.7F  SNOW    11:1| 0.3|| 0.4    0.028|| 0.04     0.00|| 0.00    0.00|| 0.00   100|  0|  0
110121/0800Z  44  07005KT  27.5F  SNOW    10:1| 0.2|| 0.7    0.024|| 0.06     0.00|| 0.00    0.00|| 0.00   100|  0|  0
110121/0900Z  45  07007KT  27.0F  SNOW    10:1| 0.3|| 1.0    0.031|| 0.09     0.00|| 0.00    0.00|| 0.00   100|  0|  0
110121/1000Z  46  07007KT  26.6F  SNOW    11:1| 0.3|| 1.3    0.031|| 0.13     0.00|| 0.00    0.00|| 0.00   100|  0|  0
110121/1100Z  47  07008KT  26.6F  SNOW    11:1| 0.3|| 1.6    0.028|| 0.15     0.00|| 0.00    0.00|| 0.00   100|  0|  0
110121/1200Z  48  07008KT  26.4F  SNOW    15:1| 0.3|| 2.0    0.024|| 0.18     0.00|| 0.00    0.00|| 0.00   100|  0|  0
----------------------------------------------+----++-------------++--------------++-------------++-----------+---+---
110121/1300Z  49  07008KT  26.4F  SNOW    15:1| 0.3|| 2.3    0.020|| 0.20     0.00|| 0.00    0.00|| 0.00   100|  0|  0
110121/1400Z  50  05007KT  26.8F  SNOW    15:1| 0.3|| 2.6    0.020|| 0.22     0.00|| 0.00    0.00|| 0.00   100|  0|  0
110121/1500Z  51  02007KT  27.0F  SNOW    17:1| 0.5|| 3.0    0.028|| 0.24     0.00|| 0.00    0.00|| 0.00   100|  0|  0
110121/1600Z  52  36008KT  26.8F  SNOW    21:1| 0.6|| 3.6    0.028|| 0.27     0.00|| 0.00    0.00|| 0.00   100|  0|  0
110121/1700Z  53  35009KT  26.2F  SNOW    21:1| 0.6|| 4.2    0.028|| 0.30     0.00|| 0.00    0.00|| 0.00   100|  0|  0
110121/1800Z  54  34010KT  26.4F  SNOW    18:1| 0.4|| 4.6    0.020|| 0.32     0.00|| 0.00    0.00|| 0.00   100|  0|  0
----------------------------------------------+----++-------------++--------------++-------------++-----------+---+---
110121/1900Z  55  33010KT  26.8F  SNOW    15:1| 0.2|| 4.7    0.012|| 0.33     0.00|| 0.00    0.00|| 0.00   100|  0|  0

[MJHUB]

I would take the Local accuweather amout of 5.5 inches for me in Seekonk and run, then again they had me getting 6 inches yesterday which was clearly a failure. 5 inches in RI/MA border is perfect next week we. icing is already a problem as i busted my ass leaving the house this morning throw some powder ontop and driving is a no go.

[mahk_webstah]

12Z NAM EVALUATION

ANY INITIALIZATION ERRORS WITH THE NAM DO NOT APPEAR TO

SIGNIFICANTLY IMPACT ITS SOLUTION.

...CLIPPER DEVELOPING INTO NORTHEAST SHRTWV TROF WITH MID-ATLC NEW

ENG COASTAL SFC LOW ...

NAM HAS TRENDED FASTER AND SHARPER WITH THE DEVELOPING TROF

ESPECIALLY EARLY IN THE PD. THIS CORRESPONDS TO A FASTER/STRONGER

LOW DEVELOPMENT... BUT QPF TO NEW ENG DOES NOT SEEM TO BE

SIGNIFICANTLY DIFFERENT THAN 00Z CYCLE. THE LOW TRACK SEEN IN THE

NAM IS ON THE EAST SIDE OF THE SPREAD.

[Organizing Low]

my 12-18 lollis might bust