FORECAST DISCUSSION: "The Storm They Couldn't Punt" 2/7-2/9

[phlwx]

For PHL, if you throw out the outliers on either side the mean on SREF is about 4.3.

[Boch23]

I know we are still ironing out the details but does anyone have a rough time line of the storm. Most important would be if we change to snow, when the change over would occur.

[tombo82685]

I know we are still ironing out the details but does anyone have a rough time line of the storm. Most important would be if we change to snow, when the change over would occur.

it looks like after eve rush for philly metro

[NaoPos]

Looks like they dropped totals from yesterday? (previous map)

[dssbss]

I know up towards North/West (Berks County) we should be more frozen?  Is the precip supposed to start for AM tomorrow in this area?  I help to decide school delays and I am wondering.

[am19psu]

I know up towards North/West (Berks County) we should be more frozen?  Is the precip supposed to start for AM tomorrow in this area?  I help to decide school delays and I am wondering.

No, it looks like start time, at the earliest changeover/worst case scenario, would be around noon. Most likely occurs after 7pm.

[dssbss]

Thanks...

[Allsnow]

Kind of weenie of me but does someone have a idea of start and end time for edison area? Thank you

[tombo82685]

Kind of weenie of me but does someone have a idea of start and end time for edison area? Thank you

looks like tomorrow morning and ends saturday morning after sunrise, that's off the euro.

[Allsnow]

looks like tomorrow morning and ends saturday morning after sunrise, that's off the euro.

Thanks Tom. Is it 100% snow here, looks like I would mix per euro

[tombo82685]

Thanks Tom. Is it 100% snow here, looks like I would mix per euro

 

you may mix some probably, but the euro has 10 plus for you from the map i saw.

[RedSky]

battle of the models euro vs american as usual. These situations usually work out as a compromise between them. euro has 6-9" upper bucks others would be 2-4" so i think best guess as of now is 3-6" 

[Quakertown needs snow]

3-6" is a good estimate for our area Red, IMO at this time.

Should beat my 4.1", biggest hit of the season .

[chubbs]

SREF 12-hr snow probability from 03z run. These have been increasing in our area for past day or so.  Probability over entire event would be higher to the NE where snow lasts more than 12-hr

[tombo82685]

9z srefs are the wettest yet for the metro area. 1.5 to ttn.. 1.25 to phl... 1 inc back to rdg... looks like atleast .25 frozen in phl

[tombo82685]

Will be interesting to see the sref plumes. They  ramped up the back end of the storm compared to 3z. 

[chubbs]

Will be interesting to see the sref plumes. They  ramped up the back end of the storm compared to 3z. 

 They are a nice improvement. Mean really wraps back the snow as the storm bombs offshore.

[HM]

Interesting how the snowfall projections are moving closer and closer to climo of monster New England-NYC events. I know analogs and descriptions have suggested "miller b" climo but this isn't entirely accurate. For example, Jan 2005 had no southern stream s/w exploding up the East Coast. It was entirely northern stream. But anyway, usually there is a decent gradient between ILG and TTN with these as the northern stream s/w dives toward the DELMARVA. The caveat here is that we aren't waiting for cyclogenesis like a usual Miller B; we are waiting for it to phase with an already intensifying southern wave moving up the coast. Should be interesting to see that kind of moisture being thrown back into the deformation zone of the northern s/w.

Could be a big, big storm now for N NJ-NYC...not just a run-of-the-mill winter storm warning event.

[tombo82685]

Interesting how the snowfall projections are moving closer and closer to climo of monster New England-NYC events. I know analogs and descriptions have suggested "miller b" climo but this isn't entirely accurate. For example, Jan 2005 had no southern stream s/w exploding up the East Coast. It was entirely northern stream. But anyway, usually there is a decent gradient between ILG and TTN with these as the northern stream s/w dives toward the DELMARVA. The caveat here is that we aren't waiting for cyclogenesis like a usual Miller B; we are waiting for it to phase with an already intensifying southern wave moving up the coast. Should be interesting to see that kind of moisture being thrown back into the deformation zone of the northern s/w.

Could be a big, big storm now for N NJ-NYC...not just a run-of-the-mill winter storm warning event.

could we expect any ratios higher than 10:1 I know the wind is going to beat that up and the 700mb temps aren't ideal, but the lift seems pretty good.

[Voyager]

9z srefs are the wettest yet for the metro area. 1.5 to ttn.. 1.25 to phl... 1 inc back to rdg... looks like atleast .25 frozen in phl

 

I don't have access to that stuff, and am not feeling good today (kidney stone). What does it show, if you can see it, for back my way? I'd assume it's a bit less than RDG or ABE. Also, is it mostly/all frozen, or do we get significant p-type issues here as well?

[NaoPos]

Interesting how the snowfall projections are moving closer and closer to climo of monster New England-NYC events. I know analogs and descriptions have suggested "miller b" climo but this isn't entirely accurate. For example, Jan 2005 had no southern stream s/w exploding up the East Coast. It was entirely northern stream. But anyway, usually there is a decent gradient between ILG and TTN with these as the northern stream s/w dives toward the DELMARVA. The caveat here is that we aren't waiting for cyclogenesis like a usual Miller B; we are waiting for it to phase with an already intensifying southern wave moving up the coast. Should be interesting to see that kind of moisture being thrown back into the deformation zone of the northern s/w.Could be a big, big storm now for N NJ-NYC...not just a run-of-the-mill winter storm warning event.

That include the poconos region? I'm selling out and staying up @ a cabin by Camelback.

And quick question, Seeing that this isn't purely Miller A, and not Miller B either, sort of a hybrid A/B? I know MIller A's are purely southern stream (maybe a quick transfer by the carolinas), and Miller B's are Northern stream redevelopers. This seems to me to fit between those 2?

[HM]

 

could we expect any ratios higher than 10:1 I know the wind is going to beat that up and the 700mb temps aren't ideal, but the lift seems pretty good.

 

In this case, I would assume 10:1 ratios and then we'll have a better look at the omega in the SGZ on the 12z runs to determine if we can get to 12-15:1. Definitely hope we can get a few posts from Tony about that, if need be. But usually we are near 10 or 12 to 1 in these setups.

[tombo82685]

I don't have access to that stuff, and am not feeling good today (kidney stone). What does it show, if you can see it, for back my way? I'd assume it's a bit less than RDG or ABE. Also, is it mostly/all frozen, or do we get significant p-type issues here as well?

.75-1, you probably mix or flip to rain during the lull periods. Most of the precip should be frozen.

[chubbs]

Interesting how the snowfall projections are moving closer and closer to climo of monster New England-NYC events. I know analogs and descriptions have suggested "miller b" climo but this isn't entirely accurate. For example, Jan 2005 had no southern stream s/w exploding up the East Coast. It was entirely northern stream. But anyway, usually there is a decent gradient between ILG and TTN with these as the northern stream s/w dives toward the DELMARVA. The caveat here is that we aren't waiting for cyclogenesis like a usual Miller B; we are waiting for it to phase with an already intensifying southern wave moving up the coast. Should be interesting to see that kind of moisture being thrown back into the deformation zone of the northern s/w.

Could be a big, big storm now for N NJ-NYC...not just a run-of-the-mill winter storm warning event.

Starting to look like a run of the mill moderate event for ilg-ttn. Easily the biggest storm of the year.

[NaoPos]

NAM looks better compared to 0z @ 18hours.

Heavier qpf towards middle of the carolinas instead of the coast. Looks slightly stronger (2-4mbs)... Small improvements, but looks to be for the better.

[HM]

 

That include the poconos region? I'm selling out and staying up @ a cabin by Camelback.

And quick question, Seeing that this isn't purely Miller A, and not Miller B either, sort of a hybrid A/B? I know MIller A's are purely southern stream (maybe a quick transfer by the carolinas), and Miller B's are Northern stream redevelopers. This seems to me to fit between those 2?

 

Yes you are going to benefit from the northern stream going negatively tilted and diving toward the DELMARVA coastline. The deformation zone will hang out over our region through about 9z Saturday or so.

I would call this setup a hybrid for sure with a lean toward a miller A.

[Quakertown needs snow]

[NaoPos]

NAM Coming in WAYY Better looking than 0z. the h5 vort down south is a lot more presentable, and the northern stream is digging more. Earlier phase ongoing.

[Quakertown needs snow]

nam looks colder at hr30, probably snow at abe, northern bucks

[ChescoWx]

Just ran Wxsim with 6z data and it has trended colder but I am now growing convinced this will be a much colder storm than currently modeled. Fresh cold air is drilling down from the NNE and I believe the Wxsim will bust quite a bit too high today (it currently has highs today here of 37 - I would bet we do not even get to freezing). Not saying this will be an all snow event but for areas N and W of the city I am thinking Steve D may be on to something that we never go to plain rain. Still believe this will be a greater than 5" storm here in NW Chesco which will make this the biggest storm of the winter to date.