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WinterWxLuvr

January Medium/Long Range Discussion Part 2

1,216 posts in this topic

35 minutes ago, SnowGoose69 said:

Someone here probably can remember the date.  I want to say it was prior to the blizzard but it was relatively historic in that I'd never before seen that happen

There was a storm about a week before or maybe 10 days that was forced under the blocking and took a decent track but there was no cold anywhere. It was frustrating. That might be the one your talking about. 

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8 minutes ago, psuhoffman said:

There was a storm about a week before or maybe 10 days that was forced under the blocking and took a decent track but there was no cold anywhere. It was frustrating. That might be the one your talking about. 

Meh, there are no numbers less than 40 in the Canadian number system,  hence cold cannot make it south of 40N. 

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00z NAM at the very end of its run has SN/IP/FRZ Rain in C VA... 1047 high exactly where we want it placed, with 1042 contour wedged beneath us

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Just checked the sounding on the NAM imby (because I'm desperate! ), and it looks like it would fall as snow after initial period of sleet.  Dry air would clearly drop temps once precip started.

CAVEAT: I AM A PATHETIC WEENIE. DO NOT READ THIS POST.

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Just now, mitchnick said:

Just checked the sounding on the NAM imby (because I'm desperate! ), and it looks like it would fall as snow after initial period of sleet.  Dry air would clearly drop temps once precip started.

CAVEAT: I AM A PATHETIC WEENIE. DO NOT READ THIS POST.

This is an outstanding post.  Thank you sir.  

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84 nam colder then 18z gfs for same time stamp fwiw..maybe mean  little but..euro also colder so..

As others have stated this event will surely trend colder for Saturday 

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Here's what I'm talking about wrt the dry air dropping temps very soon after the onset of precip. Per text sounding, max temp is +.8c at 1851 meters above ground while rh is 16.3%.

 

52162510_profile.gif

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this is great and all but the precip is so spotty on all the models....

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36 minutes ago, Ji said:

this is great and all but the precip is so spotty on all the models....

Gfs stepped it up to .25 or more for most of us by 18z sat. #trending 

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2 hours ago, yoda said:

QPF all frozen?

The trend continues. Euro drops 1.5-2.5" of snow through 18z sat and light ice after. Midlevels good through 18z sat and surface below 32 for most through 6z sun.  Lol. 

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1 minute ago, Bob Chill said:

The trend continues. Euro drops 1.5-2.5" of snow through 18z sat and light ice after. Midlevels good through 18z sat and surface below 32 for most through 6z sun.  Lol. 

Nice. Thanks for the info Bob.

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The trend continues. Euro drops 1.5-2.5" of snow through 18z sat and light ice after. Midlevels good through 18z sat and surface below 32 for most through 6z sun.  Lol. 


Best snow run of the winter!

Sent from my SM-G930V using Tapatalk

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00Z EPS snowfall mean has improved once again for the week end time period. Puts the whole of MD, except the southern eastern shore, into the half inch category. Northern portions of counties bordering the MD/PA line are now sitting within the 1' inch except for NE MD, the snow capital, where the 1 inch line juts down. Total precip through the weekend period sits at roughly .25 for the whole metro region. 

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CMC and GFS for this weekend. Some of this will likely be sleet/freezing rain. Gotta watch that chance.

Are we allowed to post EURO maps?

cmc2.png

GFS1.png

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Talking at range, a day or two centered around day 13, but in my opinion at this time the GEFS and the EPS are both strongly signaling a somewhat significant low somewhere in the eastern portion of the CONUS and have been for several runs now. As far as track, temps, snow, no snow etc... no idea. Those are facts that would come into better clarity the next week or so. That is if the models even hold onto this signal over subsequent runs. 

00Z EPS mean shows a strong low in the lakes earlier in the period with a transfer of a low off of OC later in the period. Casually glancing over the individual ensembles show a different story though. The solutions being thrown out are varied but the two major camps seem to be a major low in the lakes earlier in the period or a fairly strong coastal low later in the period. And again there are many solutions being thrown out but most of the members agree on a fairly strong if not significant low from the Midwest to off the coast. I will mention that the trough placement and axis favors a more westerly solution.

Like the EPS the 00Z GEFS members also have varied solutions with the two major camps being a strong Great Lakes low or a strong southern low running up the coast. The 500's though support the solution of a southern storm running up the coast.

Not to be left out the 00Z CMS also supports the southern low with low mslp mean anomalies showing a low in the gulf running up the Eastern seaboard. The 500's support this solution as well. 

It will be interesting to see if the models hold onto this and if they do how they evolve.

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10 minutes ago, snowdude said:

CMC and GFS for this weekend. Some of this will likely be sleet/freezing rain. Gotta watch that chance.

Are we allowed to post EURO maps?

 

 

From free sites and their limited maps, yes. From the pay sites, not so much.

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Noticeable shift south with the boundary for this weekend on the 06Z GFS. Can be seen by looking at the snowfall maps that have shifted everything south 25-50 miles.

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17 minutes ago, showmethesnow said:

Noticeable shift south with the boundary for this weekend on the 06Z GFS. Can be seen by looking at the snowfall maps that have shifted everything south 25-50 miles.

Not surprised. I posted yesterday that this had the look of something sneaky with the cold high pressing down and a stalled front to the south with waves moving along it. Its trending towards a light snow to ice event especially the northern part of MD and N VA. Euro has been hinting at this for a few runs.

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At least things haven't gone to a raging dumpster fire. This weekend event has remained relevant against the odds given the overlying h5 pattern. Then by the time we get to next week we may see some potential on the horizon with enough clarity to start tracking. At the least the pattern is moving towards workable out at range. 

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35 minutes ago, showmethesnow said:

Talking at range, a day or two centered around day 13, but in my opinion at this time the GEFS and the EPS are both strongly signaling a somewhat significant low somewhere in the eastern portion of the CONUS and have been for several runs now. As far as track, temps, snow, no snow etc... no idea. Those are facts that would come into better clarity the next week or so. That is if the models even hold onto this signal over subsequent runs. 

00Z EPS mean shows a strong low in the lakes earlier in the period with a transfer of a low off of OC later in the period. Casually glancing over the individual ensembles show a different story though. The solutions being thrown out are varied but the two major camps seem to be a major low in the lakes earlier in the period or a fairly strong coastal low later in the period. And again there are many solutions being thrown out but most of the members agree on a fairly strong if not significant low from the Midwest to off the coast. I will mention that the trough placement and axis favors a more westerly solution.

Like the EPS the 00Z GEFS members also have varied solutions with the two major camps being a strong Great Lakes low or a strong southern low running up the coast. The 500's though support the solution of a southern storm running up the coast.

Not to be left out the 00Z CMS also supports the southern low with low mslp mean anomalies showing a low in the gulf running up the Eastern seaboard. The 500's support this solution as well. 

It will be interesting to see if the models hold onto this and if they do how they evolve.

The day 13 deal looks like it could be something Miller B-ish, but at least for now per the EPS, it would be difficult to get enough cold in here until after that potential storm. Certainly worth watching for trends, but that likely would be a more western track. Probably a few days too soon in the pattern progression.

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Just now, C.A.P.E. said:

Not surprised. I posted yesterday that this had the look of something sneaky with the cold high pressing down and a stalled front to the south with waves moving along it. Its trending towards a light snow to ice event especially the norther part of MD and N VA. Euro has been hinting at this for a few runs.

Been interesting watching the models on this feature. Just a few days ago the Euro had the boundary north of our area into central if not northern PA. GFS was south at that point and then started moving towards the Euro's northern solution as the Euro started moving south towards the GFS' old solution, Now we have the GFS moved back and in fairly good agreement with the Euro. Fun times. :)

Question, if you know. Euro has a tendency to under do precip totals on the North and western sector when dealing with coastals. Do you know off hand if that may also be the case when dealing with impulses running across a boundary? I myself can't recall. I ask because we see a little disconnect between the GFS and the Euro in that regards.

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16 minutes ago, showmethesnow said:

Noticeable shift south with the boundary for this weekend on the 06Z GFS. Can be seen by looking at the snowfall maps that have shifted everything south 25-50 miles.

The precip type totals show it well.  Note this includes the rain we're getting this week before the weekend event.  

IMG_0025.PNG

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When I saw both the GFS and EC prog a 1040+ High to our north (Hudson Valley) reinforced by the strong upper level confluence, and the elongated SW upper flow, I thought man that looks like ice for us. I kept thinking wait until this gets into the NAM's range -- say what you want about the NAM, but it does have better vertical resolution in the low levels compared to the globals. Thus it came as no surprise that the NAM (3km in particular) did better in the last fzra even in maintaining the sub-freezing surface temps -- which would be the preferred trend so long as it's precipitating and/or you've already got an ice layer going. That diabatic/latent cooling from evaporation and any ice that's melting keeps us stuck at 32F or lower a lot longer than MOS would suggest in these types of CAD setups. It'll come down to how much precip can we can squeeze out if this. 

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11 minutes ago, nj2va said:

The precip type totals show it well.  Note this includes the rain we're getting this week before the weekend event.  

IMG_0025.PNG

6z GFS is a nice little event even for DC, much colder than previous runs.  The 12 hour precip map from at 84 hour has DC in the 0.25 contour and according to TT precip maps it's still frozen.  Maybe an inch of snow and a little crust on top.    

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EURO has DCA above freezing for all but 27 of the next 228 hours; however IF it holds, light snow could begin Saturday morning around 3 AM and continue into the early afternoon (0.19 liquid by 1 PM Sat when 800 mb T touches 0 C) before changing to light sleet/freezing rain (0.14 liquid).  Ambient Temperature rising very slowly from 29 to 32. 

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