February 15-MOrch possible wintry threats

[phlwx]

Friday of next week looks more interesting in my view. 

 

Next weekend might be the last really good shot at a solid winter storm for the season if the warm signal for March is to be believed.  Obviously could snow later into March but in terms of getting an equal opportunity storm, that might be the last really solid shot.

[chubbs]

Also, let me just, for the sake of hype (lol), say this:

If the NAO can become more defined than what, say, the GFS portrays, I am prepared to up the probability of a KU storm in our area. At this time, I am holding the idea from yesterday and still favoring something "sub KU levels" for our area but notable/significant (like a 6-12" type of snow).

Between the next set of Pac waves and NAO, there is definitely a chance this entire things trends more south and east initially before it jumps to the coast.

 

As advertised nice shift SE last night's guidance.

[chubbs]

Next weekend might be the last really good shot at a solid winter storm for the season if the warm signal for March is to be believed.  Obviously could snow later into March but in terms of getting an equal opportunity storm, that might be the last really solid shot.

 

Models are indicating that the storm chances continue after next weekends storm. The D10 Euro ensemble shows a split flow with an active southern stream. GEFS are similar and continue the pattern well beyond D10 with a nice west based -NAO developing. 

[jrodd321]

Does this image excite any one else? I think this would scream snowstorm for us. 

 

[Allsnow]

Does this image excite any one else? I think this would scream snowstorm for us.

Why are the euro and gfs shearing it out after? Is this something we should be concerned about?

[tombo82685]

Why are the euro and gfs shearing it out after? Is this something we should be concerned about?

Confluence shears it out, It definitely can happen. The storm is 7 days away. If it has it like that by tues night i would. 

[Allsnow]

Confluence shears it out, It definitely can happen. The storm is 7 days away. If it has it like that by tues night i would.

Do you like the pattern for a storm at the end of next week?

[tombo82685]

Do you like the pattern for a storm at the end of next week?

Yes...you have blocking, a nice high in place with a 50/50 low. If there is a storm i would favor frozen based on those aspects. Keep in the back of your mind that their are ways it may not work out. For instance, the block weakens and it cuts and redevelops to late for us. Or that it gets sheared out.

[Zir0b]

12z ggem looked absolutely ridiculous for next week and beyond...in a good way

[Mitchell Gaines]

I still think Friday will shift south on the models, maybe similar to an event a few weeks ago that tried to cut into an arctic airmass. Modeling seven days out had it cut into Canada then there was even a danger that system would go to far south as time got closer. we'll see. 

[WeatherQ]

Yes...you have blocking, a nice high in place with a 50/50 low. If there is a storm i would favor frozen based on those aspects. Keep in the back of your mind that their are ways it may not work out. For instance, the block weakens and it cuts and redevelops to late for us. Or that it gets sheared out.

 

With the 12z models yesterday honking for a storm and now 60F outside and NOTHING for this weekend, I just can't buy into a solid threat next weekend, whether its at hour 176 or 216. Even with the modeling of a +PNA, west-based -NAO and -AO. Then there's the absolute fantasy snowmeggedon at Hr 384.

 

With this Winter.....Can almost hear the faint tones of Don Meredith from Monday Night Football back in the day....."Turn out the lights....the party's over......"

 

Should be an interesting severe weather season. Bring it.

[tombo82685]

I still think Friday will shift south on the models, maybe similar to an event a few weeks ago that tried to cut into an arctic airmass. Modeling seven days out had it cut into Canada then there was even a danger that system would go to far south as time got closer. we'll see. 

the 12z euro brought it further south than sheared it. Va and dc get a nice evnt, but the precip is meh looking as it gets here. Pretty much a 1-3 ordeal with the 2-3 out towards lns and mdt. The day 10 euro has a nice storm, but that's way out.

[Porsche]

the 12z euro brought it further south than sheared it. Va and dc get a nice evnt, but the precip is meh looking as it gets here. Pretty much a 1-3 ordeal with the 2-3 out towards lns and mdt. The day 10 euro has a nice storm, but that's way out.

It seems like it's always 7-10 days out and then falls apart, hopefully things turn around, at least Adam and HM have been on board for something next weekend.

[Ellinwood]

Models have been somewhat consistent with next Friday's storm threat. Solid HP to put some CAD in place that will allow for some front-end snow and/or sleet and freezing rain. It's generally looking like a good snow will depend on when and where a secondary low develops after the primary low over the Midwest occludes and weakens. The GFS Op+Ens gets the secondary low cranking faster and further north, which allows for the wetter solution compared to the Euro Op+Ens.

[wxphanatic]

Question about the "always ten days out" phenomenon. For the mets -- is this actually a tendency of the models -- are they prone to developing vortices / LP systems as an artifact of the the model physics behind the models, especially in the long range when the model output is furthest removed in time from the obervational data -- or is this just a perception. That is, we focus on the vortices in the modeling and somehow exaggerate their frequency as compared to reality.

 

Not sure I'm making myself clear, but I guess I am asking about whether there is model feedback such that the long range always has more whopping storms than reality ever does...

[HM]

The models will always do spurious things as you get out in time. All that matters is that we have a legitimate -NAO to contend with which increases the threat for wintry weather 2/21-2/26. Anything sliding under this feature will have the potential to produce snowfall in the Mid Atlantic.

Analogs are not overwhelming for something major but there are a few decent years showing up (see other thread). It is always an interesting thing when the AJ retreats but leaves behind a bunch of eddies / sufficient cold air for snow (sort of like spring wavelengths with winter cold). You can get some very awesome setups with blocking like this. Of course, there were plenty of boring results, too, in past years with somewhat similar patterns.

[fsu_wxgirl]

Both the GFS and Euro look like they are trending a little but colder at 850 for the Tuesday system. Surface temps are still above freezing so possibly looking at freezing rain/wintry mix. In my forecast yesterday I had western PA in the freezing rain, so may have to adjust it a little further east if this continues to be the trend. 

[eastonwx]

Both the GFS and Euro look like they are trending a little but colder at 850 for the Tuesday system. Surface temps are still above freezing so possibly looking at freezing rain/wintry mix. In my forecast yesterday I had western PA in the freezing rain, so may have to adjust it a little further east if this continues to be the trend. 

Start times may impact ptypes as well? I thought I read models showing differences in start?

[fsu_wxgirl]

Precip in the GFS starts a little sooner than the Euro, but not by much. Both look to start around lunch time and then keep precip in our area through the evening hours. 

Start times may impact ptypes as well? I thought I read models showing differences in start?

[Isotherm]

Here's a potential problem with the friday potential. Note the GFS ensembles H5 pattern progged below; it seems to be a situation similar to late dec in which we had an ineffective "blocking ridge" in central-eastern Canada, but this ridge was not strong or expansive enough across the NATL to really suppress the baroclinic zone.

This height anomaly forecast is slightly concerning b/c we see the SE Ridge "hooking up" with the Canadian mid level ridge like we saw earlier this winter. So although we've got a great 50/50 low and some ridging in Canada, it's not true blocking if the height anomaly fields link up from Florida northward to Canada. This could allow the primary low to cut very far north as current models are depicting, though a secondary would eventually have to develop, it might not be far enough south to do us much good.

We'll have to monitor this situation, but if this occurs it basically goes along with the theme of the winter. So close, yet so far. Another ineffective ridge that classifies as a technical -NAO. Maybe we'll change this situation after the 20th.

The MJO pulse through 7-8-1 did manage to produce a monster snowstorm on the 8th of feb, a light even this past Wed, and a mdt event for eastern New England right now. The MJO will be cycling through phases 4-5 over the next 7 days, which should promote a retrogression of the mean trough axis into the Rockies for the time being. This coincides w/ the current forecast of heights falling in the West, rising in the East, making the Friday event an unlikely producer of meaningful snow.

I think our next real window of opportunity for snow accumulation greater than an inch or two is probably the last week of February into the first week of March. Will have to see if the MJO cuts through the COD and propagates back into the more favorable octants by D 5-8, at which time we could see another 1-2 week pulse of snow chances like we just came out of. But as it stands, the friday potential doesn't look great to me.




 

•  

[Isotherm]

With a low in the lakes, the Tuesday event is torcherama for the coastal plains. Probably low 50s.

[rossi]

With a low in the lakes, the Tuesday event is torcherama for the coastal plains. Probably low 50s.

Latest GFS has rain to snow on Tuesday- any comments?

 

Rossi

[famartin]

Latest GFS has rain to snow on Tuesday- any comments?

 

Rossi

Where?  Not in Manalapan, that's for sure.

[famartin]

Latest GFS has rain to snow on Tuesday- any comments?

 

Rossi

No snow on this sounding, that's for sure.

[tombo82685]

Here's a potential problem with the friday potential. Note the GFS ensembles H5 pattern progged below; it seems to be a situation similar to late dec in which we had an ineffective "blocking ridge" in central-eastern Canada, but this ridge was not strong or expansive enough across the NATL to really suppress the baroclinic zone.

This height anomaly forecast is slightly concerning b/c we see the SE Ridge "hooking up" with the Canadian mid level ridge like we saw earlier this winter. So although we've got a great 50/50 low and some ridging in Canada, it's not true blocking if the height anomaly fields link up from Florida northward to Canada. This could allow the primary low to cut very far north as current models are depicting, though a secondary would eventually have to develop, it might not be far enough south to do us much good.

We'll have to monitor this situation, but if this occurs it basically goes along with the theme of the winter. So close, yet so far. Another ineffective ridge that classifies as a technical -NAO. Maybe we'll change this situation after the 20th.

The MJO pulse through 7-8-1 did manage to produce a monster snowstorm on the 8th of feb, a light even this past Wed, and a mdt event for eastern New England right now. The MJO will be cycling through phases 4-5 over the next 7 days, which should promote a retrogression of the mean trough axis into the Rockies for the time being. This coincides w/ the current forecast of heights falling in the West, rising in the East, making the Friday event an unlikely producer of meaningful snow.

I think our next real window of opportunity for snow accumulation greater than an inch or two is probably the last week of February into the first week of March. Will have to see if the MJO cuts through the COD and propagates back into the more favorable octants by D 5-8, at which time we could see another 1-2 week pulse of snow chances like we just came out of. But as it stands, the friday potential doesn't look great to me.

 

•  

What also doesn't help is when that storm does cut towards the lakes it just rots underneath that block. The constant sw winds just warms the mid levels and screws things up for the next storm as currently modeled.

[NEG NAO]

Latest GFS has rain to snow on Tuesday- any comments?

 

Rossi

you must be looking at hour 60 where on the map the 850 line has passed us with mod precip showing in back BUT take a look at the temps at the other levels - too warm

[Heisy]

Rossi,

 

That's a cold front buddy, precip falls before temps drop. 

[Rainshadow]

you must be looking at hour 60 where on the map the 850 line has passed us with mod precip showing in back BUT take a look at the temps at the other levels - too warm

 

This, plus one can't look at the fcst hr temp profile and assume all that pcpn is falling with that profile.

[Rainshadow]

What also doesn't help is when that storm does cut towards the lakes it just rots underneath that block. The constant sw winds just warms the mid levels and screws things up for the next storm as currently modeled.

 

FWIW, I havent looked at much past Tuesday's system, so this is just a generic thought.  If one was to go by the Archambault thesis, based on the GEFS NAO Outlook, it would be sometime around March 1st.  Looks like the MJO "would" be in the COD so less of a downer.  The latitudional track of the secondary the GFS has for Fri/Sat is at least consistent with the NAO being negative and not changing much toward the end of the week. 

 

I'll still golf for it on Thu if I can get over this cold I'm getting by then, somehow my record has remained intact.

[tombo82685]

I can't tell if this is all snow or a pure paste job. From philly area 850s are below and thicknesses are 534-540. If all snow it would probably be a snow bomb of 1-2 ft for next wed into thurs.