March 26th Snowstorm - continued discussion and observations

[Clinch Leatherwood]

Just taking the panels of the NAM probably about .3 to .4 here, consistent.  I will still believe it when I see it. 

 

Pressure drops to 952 as it passes, not bad.  50-75 miles and this was a historic system but no blocking.

[Wx4cast]

Looks like "bombs-away" based on H2O sat pix. Looks to me like a tropopause fold associated with the eastern LP.

[Wx4cast]

Just taking the panels of the NAM probably about .3 to .4 here, consistent.  I will still believe it when I see it.

Pressure drops to 952 as it passes, not bad.  50-75 miles and this was a historic system but no blocking.

No blocking the story of this winter!

[CCHurricane]

NAM waits until after 3am but still hits the Cape hard and gets measurable into eastern MA.

 

Per the 00z NAM fwiw...Pinwheel precip comes a bit closer to shore.

 

Hyannis (dead center of Cape Cod) = 10 inches of snow

 

Chatham (eastern Cape Cod) = 14 inches of snow

 

Nantucket = 16 inches of snow

[Clinch Leatherwood]

No blocking the story of this winter!

 

Yet we had a good winter.  This is really one for the history/text books.

This one tonight.  I'm being grumpy out of frustration BUT.....  normally I look for the .5 line as the near/back edge of the heavy snow.   I follow that a lot for systems that come so close it rains just out of curiosity.   Normally it's a very good guide for around where, or actually slightly EAST of where the real heavy bands will back.  A lot of times the .5 line ends up being a crude divider between the really heavy snows as the deform band sets up, and much less.

 

The NAM still has that right around the SE tip of PYM County and by the canal.  The gradient is almost grid scale at that point IMO.  Either it's compensating and we are going to see the heavy stuff stop around the eastern Cape or maybe it's the other way and the really heavy stuff is actually going to get west for a time into extreme SE MA/canal area.

 

Something to watch, as it could mean maybe a really heavy band of so does make it to the mainland.

[powderfreak]

I'm thinking the same, The trends have been east and with such a sharp cut off NW it won't take much of a shift to the east to really cut into the accumalations

The dreaded last minute east shift after forecasts get ramped up high...we've all seen that before. I think in coastal systems it seems more likely for a system to be further east than progged. It seems rarer to get that stronger and more west finish than 24 hour progs have in east coast cyclones for whatever reason.

[Ginx snewx]

Yeah it's clearly way offshore. I think the 0z runs will continue moving it east. I really don't expect this to be much of a deal at all the western 1/2 of the Cape. Even the winds look manageable now.

NAM has 90 knots at 925 on the Cape with 110 knots just offshore

[dryslot]

The dreaded last minute east shift after forecasts get ramped up high...we've all seen that before. I think in coastal systems it seems more likely for a system to be further east than progged. It seems rarer to get that stronger and more west finish than 24 hour progs have in east coast cyclones for whatever reason.

 

Its is with this type and the fact its more of a Miller A, Which i don't particularly like, I would much rather have a Miller B type system to deal with lot less chance of something going wrong as it gains latitude up this way, To many times i have watched these Miller A's do the ENE jog once they hit the BM instead of continuing NNW

[Clinch Leatherwood]

NAM has 90 knots at 925 on the Cape with 110 knots just offshore

 

Yeah NAM is still impressive but it's also 10 mb stronger than most of the guidance up to this point. 

 

4km NAM is further west with the precip and would involve most of east coastal MA in the heavier stuff. 

 

Schools are already closing down here, so it had better snow or the ire of angry parents will far outshine their ire for the weathermen.

[TauntonBlizzard2013]

People are outraged that school isn't called off here yet. Its like they look at a weenie map 5 days ago, and never look again. My boss told me today Bridgewater was getting 8-12. I told him there's a better shot we may not see a single flake lol

[HIPPYVALLEY]

The dreaded last minute east shift after forecasts get ramped up high...we've all seen that before. I think in coastal systems it seems more likely for a system to be further east than progged. It seems rarer to get that stronger and more west finish than 24 hour progs have in east coast cyclones for whatever reason.

 

I dunno' it seems to go both ways.  Living out here I dread the E shift but when I lived on the coast it felt like we were often dealing with the dreaded tick W and p-type issues.  Maybe the difference between Miller A's vs B's as Dryslot mentioned and without doing historical analysis I can't really say. 

[Clinch Leatherwood]

Ginxy, happy face on....the 18z RGEM was a step up, and the 0z NAM and 4km are probably two of the harder hitting runs for this system.  Interesting trends, partially owed to 950ish I'm sure.  Let's see what shakes.

 

NAM has a wall of snow spinning in from the SSE in about 2 hours.

[SouthCoastMA]

NAM says Phil ftw

[Clinch Leatherwood]

996 to 949 in 18 hours...wtf.  Is that even possible?

[Wx4cast]

Yet we had a good winter.  This is really one for the history/text books.

This one tonight.  I'm being grumpy out of frustration BUT.....  normally I look for the .5 line as the near/back edge of the heavy snow.   I follow that a lot for systems that come so close it rains just out of curiosity.   Normally it's a very good guide for around where, or actually slightly EAST of where the real heavy bands will back.  A lot of times the .5 line ends up being a crude divider between the really heavy snows as the deform band sets up, and much less.

 

The NAM still has that right around the SE tip of PYM County and by the canal.  The gradient is almost grid scale at that point IMO.  Either it's compensating and we are going to see the heavy stuff stop around the eastern Cape or maybe it's the other way and the really heavy stuff is actually going to get west for a time into extreme SE MA/canal area.

 

Something to watch, as it could mean maybe a really heavy band of so does make it to the mainland.

Nice reasoning. I like to use some old school relationships associated w/ the cut off at H7. More often than not I have seen the precip shield much more compacted than modeled. The more contours aloft the more compacted the precip shield to the NW, often from the LP aloft back to the third/fourth closed contour.

[Ginx snewx]

Yeah NAM is still impressive but it's also 10 mb stronger than most of the guidance up to this point.

4km NAM is further west with the precip and would involve most of east coastal MA in the heavier stuff.

Schools are already closing down here, so it had better snow or the ire of angry parents will far outshine their ire for the weathermen.

any parent with any sense knows this could easily be life threatening, we are snowlovers but hurricane gusts alone and I don't want my kid outside never mind in a bus

[Clinch Leatherwood]

any parent with any sense knows this could easily be life threatening, we are snowlovers but hurricane gusts alone and I don't want my kid outside never mind in a bus

 

There's a logistic issue too along the water with some of the routes, and with the bridges and the possibility of closure. 

 

The NAM drops about 50 mb in the next 18 hours.  Not bad.

[SouthCoastMA]

996 to 949 in 18 hours...wtf. Is that even possible?

Overdone.. but here's too hoping. The NAM backs my 'thinking' that you still get 5"+.. 10 miles means so much..and its too close to write off even within 6-12 hours. At least the east ticks have stopped

[CCHurricane]

any parent with any sense knows this could easily be life threatening, we are snowlovers but hurricane gusts alone and I don't want my kid outside never mind in a bus

 

00z NAM has sustained winds between 45-55 for most of the Cape tomorrow morning, gust past 70mph for central and eastern sections on the Cape. With your without snow falling, that kind of wind can do some serious damage. Add in snow, and there's no WAY schools will have kids driving/walking to school.

 

I'm on a southern facing beach, but I'll let you guys know what my Davis Vantage Pro 2 spits out tomorrow!

[Clinch Leatherwood]

00z NAM has sustained winds between 45-55 for most of the Cape tomorrow morning, gust past 70mph for central and eastern sections on the Cape. With your without snow falling, that kind of wind can do some serious damage. Add in snow, and there's no WAY schools will have kids driving/walking to school.

 

All true but it's also all contingent on the best moisture getting west.  It's not a chance they can take because there are too many variables, so it's a wise call.

 

That said I'll believe the winds 45+ sustained when they occur.  We've had significant winds with storms this winter predicted that didn't really come close to meeting expectations.  Bad yes, but there's a huge difference between 25-35 and 45-55.

[Clinch Leatherwood]

Overdone.. but here's too hoping. The NAM backs my 'thinking' that you still get 5"+.. 10 miles means so much..and its too close to write off even within 6-12 hours. At least the east ticks have stopped

 

That's the 4k version. 996 now to a peak of 949 in 18 hours.  That's a WTF if I've ever seen one.

[JC-CT]

There's a logistic issue too along the water with some of the routes, and with the bridges and the possibility of closure. 

 

The NAM drops about 50 mb in the next 18 hours.  Not bad.

 

It's an f-ing hurricane. Not sure what else would accurately compare.

[Wx4cast]

996 to 949 in 18 hours...wtf. Is that even possible?

For a warm seclusion. When I was a marine met/forecaster/shiprouter I remember a few storms in both PO and AO dropping 45+ millibars in < than 24 hours.

[Ginx snewx]

Nice reasoning. I like to use some old school relationships associated w/ the cut off at H7. More often than not I have seen the precip shield much more compacted than modeled. The more contours aloft the more compacted the precip shield to the NW, often from the LP aloft back to the third/fourth closed contour.

When was the last time we had a sub 960? I remember a small 954 busting buoys in the GOMaine but that was a microstorm.Can't remember a storm this size since 93,there was a reason this time period analogged 93,placement aside excellent analog

[JC-CT]

I'd swear, you look at the radar and you'd go holy sht we are going to get slammed. But no, it's just gonna hang out there and create a 1000 mile wide tornado instead.

[OceanStWx]

When was the last time we had a sub 960? I remember a small 954 busting buoys in the GOMaine but that was a microstorm.Can't remember a storm this size since 93,there was a reason this time period analogged 93,placement aside excellent analog

 

Sandy? Or are we not counting that.

 

Last February ticked down to 968 as a reference.

[Wx4cast]

When was the last time we had a sub 960? I remember a small 954 busting buoys in the GOMaine but that was a microstorm.Can't remember a storm this size since 93,there was a reason this time period analogged 93,placement aside excellent analog

IIRC two storms 84-88. Not up here but more south MidAtlantic/NC Capes then East and OTS

[Wx4cast]

Sandy? Or are we not counting that.

 

Last February ticked down to 968 as a reference.

Not including Sandy

[Clinch Leatherwood]

Nice reasoning. I like to use some old school relationships associated w/ the cut off at H7. More often than not I have seen the precip shield much more compacted than modeled. The more contours aloft the more compacted the precip shield to the NW, often from the LP aloft back to the third/fourth closed contour.

 

Yep I remember you making that point a couple of times last year.  This one really has my interest again - I hope the RGEM and obs don't stomp on it.  If this type of strengthening is real I think the precip slips a little further west than what might be modeled. 

 

It's an f-ing hurricane. Not sure what else would accurately compare.

It's pretty unprecedented.

 

For a warm seclusion. When I was a marine met/forecaster/shiprouter I remember a few storms in both PO and AO dropping 45+ millibars in < than 24 hours.

 

I imagine this is something not often seen this far south.   Seems more like what we would see further north.

 

When was the last time we had a sub 960? I remember a small 954 busting buoys in the GOMaine but that was a microstorm.Can't remember a storm this size since 93,there was a reason this time period analogged 93,placement aside excellent analog

 

It's been ages.

 

Note the super tight gradient...but it's definitely shifted west again.

[Clinch Leatherwood]

I'd swear, you look at the radar and you'd go holy sht we are going to get slammed. But no, it's just gonna hang out there and create a 1000 mile wide tornado instead.

 

Pretty awesome as the western system is about to take over/phase whatever we want to call it.  How that erupts and how fast....

 

http://weather.rap.ucar.edu/satellite/displaySat.php?region=ALB&itype=wv&size=large&endDate=20140326&endTime=-1&duration=5