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Saint Patrick's Day Snow Event


stormtracker

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At 72hr when the heavy precip starts overspreading the region, GFS 0z soundings have us well bellow zero throughout the entire column.

 

http://www.twisterdata.com/index.php?sounding.lat=39.1182&sounding.lon=-77.0689&sndclick=y&prog=forecast&model=GFS&grid=3&model_yyyy=2014&model_mm=03&model_dd=14&model_init_hh=00&fhour=72&parameter=TMPF&level=2&unit=M_ABOVE_GROUND&maximize=n&mode=singlemap&sounding=y&output=image&view=large&archive=false

 

NAM soundings are looking much more like a CAD setup (66 and 69hr on the 6z run look the same, here's the 69hr):

 

http://www.twisterdata.com/index.php?sounding.lat=39.1182&sounding.lon=-77.0689&sndclick=y&prog=forecast&model=NAM&grid=221&model_yyyy=2014&model_mm=03&model_dd=14&model_init_hh=06&fhour=69&parameter=TMPF&level=2&unit=M_ABOVE_GROUND&maximize=n&mode=singlemap&sounding=y&output=image&view=large&archive=false

 

NAM is not showing snow south of the mason dixon line except in western MD, but it's QPF is up in the 1.5"+ range for the entire area for just the first half of the storm. GFS is much lighter on the precip, running 0.6 to 1" of QPF for most of the region. In the case of the GFS, the second storm mostly misses us south. SREF plumes are showing an average of 1.2" QPF (throwing out the one huge high outlier, range is 0.6 to 1.9").

 

Temperature is the real nail-biter here!

 

(Grumble, I want ECMWF but the site I use seems down...)

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looks like a nice thump of snow according to this( 6z nam) but how much qpf is actually rain because you don't list it here. Your quote says a lot of plain rain so I'm a little confused.

 

doh, yes sorry about that. here is what the output looks like. not as much rain as i made it out to be, but def a wintry mix of crap

post-115-0-13521400-1394796951_thumb.jpg

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the only way to do good in  mid march is to get a lot of liquid to fall in a short duration when it is 32 or below, the form is all snow, and it is heavy...if the models start showing that combination, I'll be more intrigued....

and that's real hard to do with a positive tilted trough.   I guess the one saving grace is that the ensembles show lots of uncertainty about the trough evolution and therefore timing of the various periods of enhanced precipitation.   I'm trying to get excited since I have to write and article but was a little disappointed after seeing the Euro.  It's 500h evolution looked better yesterday afternoon. 

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Looking at all the latest guidance it seems like we are converging on a 2-4/3-6 kind of deal with the usual suspects doing better than the usual suspects who don't. The wildcard is IF the trailing energy can add to the totals. Which will be tough given time of day and most guidance showing no big hits. Only 4 euro members show a sizeable amount of trailing precip. There's a bunch showing a tenth to a quarter but that won't get the job done.

To me attm it looks like we rely on the front running stuff and hoping we don't lose too much to warm ground or rain before the switch. Could get lucky with some good rates and it's certainly possible to have that slug juice up as we move into the short range. For now 2-4/3-6 cities and west looks like an ok call.

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This thread has absolute terrible analyzation..Its mid March, we get it..snow is not easy to come by in mid March. But this appears to be a set-up that could deliver a decent snowfall for a large part of the area. This isnt the winter of 2012, its the winter of 2014. With a decently strong Canadian high pressure dropping from Central Canada and tracking east over the north tier of the US, there can easily be a solid stripe of 3-6 inches of snow near and just west of I95. Its still about 72-84 hours out so obviously there will be wiggles in track and timing but I like my chances for >=2 inches near Baltimore at this point.

Perhaps I didn't express myself very well. My bad. I was supposed to be commenting more on the usefullness (or lack of) of the snow maps. Instead I commented more on this event than I meant to. Correct me if I am wrong, but the snow maps are total qpf as snow, not neccesarily what sticks to the ground. 4 to 8 modeled snow might turn out to be nothing more than a couple of inches when you take into account something as simple as sun angle. I love the snow maps and do hope they verify but I am not a firm believer in snow maps.

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09z SREFs have 0c 850 line SE of DCA for pretty much entire period Sun afternoon into Monday afternoon... the 0c 850 line does touche DCA at 15z MON, but then heads slowly back SE

 

2m 0c line crosses through IAD around 2am Monday (06z MON) and through DCA ~3-4am (07z-08z MON).  Temperature does not go above 32 for the rest of the run

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09z SREFs have 0c 850 line SE of DCA for pretty much entire period Sun afternoon into Monday afternoon... the 0c 850 line does touche DCA at 15z MON, but then heads slowly back SE

 

2m 0c line crosses through IAD around 2am Monday (06z MON) and through DCA ~3-4am (07z-08z MON).  Temperature does not go above 32 for the rest of the run

The srefs if correct would imply a good storm out here.  Over 1" on the means as of 87 hours with all of it falling with surface and 850's below 0.

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Thats solid news yoda, much appreciated. On mobile but knew around 9:17 SREF's come out, and had a feeling you'd post. Right on time.

 

I edited the post to add the 2m temp information.  QPF is pretty much 1"+... and its a large area of 1"+ QPF in a 24 the period (as in at hr 81 -- 18z MON, it stretches from the GOM S of FL panhandle up into SNE)

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I edited the post to add the 2m temp information.  QPF is pretty much 1"+... and its a large area of 1"+ QPF in a 24 the period (as in at hr 81 -- 18z MON, it stretches from the GOM S of FL panhandle up into SNE)

 

Think the SREFs are catching on to more energy coming out, hence greater QPF's?  I hope it's a trend setter...

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GFS is a pretty good hit, relative to March.   Still holding to 3 to 5 for this storm.

 

Did you hear?  It can actually snow in March!

 

That isn't what I am seeing.  I see a storm that plows into a bootleg air mass with unimpressive liquid most of which falls by midnight...then some lull....the part 2 is -SN in the middle of the afternoon....the good returns will be coming in at 8-9pm and it will be like 35......GFS is a QPF eater...and it isn't much QPF to eat....first part is maybe 0.4" plowing into a 44 degree air mass

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That isn't what I am seeing.  I see a storm that plows into a bootleg air mass with unimpressive liquid most of which falls by midnight...then some lull....the part 2 is -SN in the middle of the afternoon....the good returns will be coming in at 8-9pm and it will be like 35......GFS is a QPF eater...and it isn't much QPF to eat....first part is maybe 0.4" plowing into a 44 degree air mass

 

I agree, you need better rates than what the GFS is showing....then again, its been terrible with this event & the GGEM has shown much better rates for the initial wave run after run...

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