March 6-8th Ocean Storm Discussion Part III

[weatherMA]

What a brutal situation for TV mets. Boston could get 4" or 20". I think it's a little easier for ORH area now. 8-12" seems like a good call.

[ORH_wxman]

I am kind of wondering if there is a significant cut off even just N of bos by like even 10- 15 miles.

 

Will, not to be a pain, but for the N shore crowd and over to 128 what's KBVY or KBED lookin like if you have it near you, otherwise i think we get the picture.

 

 

BVY is like 1.5"...BED is aorund 1"...that is right on the line between ORH and RAY...maybe slightly more for BED. I hope you realize these 10 mile differences do not matter right now. If someone is 10 miles north of a place that has 0.75" more than them...that doesn't mean jack right now. It could easily shift 25 miles north or south. You just need to know that shifts will probably matter, but actually taking these locations at face value right now is not very useful.

[HarveyLeonardFan]

I just checked the DC area obs as of 1252 and the surface observations aren't as impressive as the radar.  The viz is 1.25 miles at Dulles with a temp of 33 and 35 at National Airport with a viz of 3 miles.

[Clinch Leatherwood]

What a brutal situation for TV mets. Boston could get 4" or 20". I think it's a little easier for ORH area now. 8-12" seems like a good call.

 

I'm not sure it's really that brutal.  Just back from the water I think 8+ is pretty much assured by all the models aside of the 0z NAM which is probably overruled by all of it's meso offshoots.

 

Even the woefully conservative Wunderground maps are like 15-20" just SW of Boston.  Heck even I get like 12-13" by that algorithm....conservatively.

[ORH_wxman]

I just checked the DC area obs as of 1252 and the surface observations aren't as impressive as the radar.  The viz is 1.25 miles at Dulles with a temp of 33 and 35 at National Airport with a viz of 3 miles.

 

 

They are still mixing out and dynamically cooling the warmish BL...they'll be ripping really soon.

[N. OF PIKE]

good point will. were all a little geek'd up from following this storm for 3 straight days and sometimes i lose that perspective and go overboard on model qpf trends and cut offs.

 

it's pretty late and not as busy so i also wanted to share my concern the euro was running a bit to cold during the day thursday. i think a degree or degree in ahalf difference could be huge wrt ratio's esp with firehose during the day.

[eduggs]

It's rare to see such modeled duration of intense QPF as showed on the Euro... and most guidance.  I love that look for SE areas.  Could be a total crush job.  But it's difficult to shake the debbie in me that notices how tiny the spatial extent of heavy snow is and how far SE the SLP tracks.  And the good stuff is still a day and a half away.  The anticipation for this snow will likely be nerve wracking.  If something's off that QPF max goes from 2.5 to .75.

[Clinch Leatherwood]

It's rare to see such modeled duration of intense QPF as showed on the Euro... and most guidance.  I love that look for SE areas.  Could be a total crush job.  But it's difficult to shake the debbie in me that notices how tiny the spatial extent of heavy snow is and how far SE the SLP tracks.  And the good stuff is still a day and a half away.  The anticipation for this snow will likely be nerve wracking.  If something's off that QPF max goes from 2.5 to .75.

 

It's all going to come down to how strong the s/w diving down is.  That's a lot of what we've got going on with the mechanisms behind the snow between the initial burst and the later stuff.  If you loop the GFS/Euro they're really pretty similar now at all levels.  The Euro is just stronger at 5h coming into PA.

 

I'd say compare the earlier GFS runs but you can't because they were so bad you can't really compare strength from earlier runs to this one.  They totally caved to the Euro.  Take a look at 57 hours on the GFS at 5h, compare to the same Euro..pretty close right but the Euro is stronger?  Now look at the 63h 18z run of the Euro...exiting the coast a few hundred miles SE.  Unusable.

 

Otherwise it's now a pretty good match for the Euro, the differences in QPF are probably now related to the weaker 5h feature.  Maybe it's right, but the fact that it's been all over the place and the Euro and others pretty consistent makes me think it just blows, TBH.

[mattb65]

It's rare to see such modeled duration of intense QPF as showed on the Euro... and most guidance.  I love that look for SE areas.  Could be a total crush job.  But it's difficult to shake the debbie in me that notices how tiny the spatial extent of heavy snow is and how far SE the SLP tracks.  And the good stuff is still a day and a half away.  The anticipation for this snow will likely be nerve wracking.  If something's off that QPF max goes from 2.5 to .75.

Yup and it goes from a long duration of hours and hours with ~1"/hr down to almost non accumulating snow for the CP if that happens.  It's definitely a tough call and I can see why the local mets are so gun-shy, it's such an unusual setup for big snows.

[N. OF PIKE]

Yup and it goes from a long duration of hours and hours with ~1"/hr down to almost non accumulating snow for the CP if that happens.  It's definitely a tough call and I can see why the local mets are so gun-shy, it's such an unusual setup for big snows.

exactly.

 

HPC percentages are sky high for just west of DC area wrt to foot plus totals.  For SNE probs are equally high for the mega totals (2ft plus) but much lower (all lower than 80) for 8 inches anwhere in SNE thru Friday nite on the 48 hour outlook. Well see how these 48 hour probs shift as event draws near....next update on them should be around 8am

[Clinch Leatherwood]

Yup and it goes from a long duration of hours and hours with ~1"/hr down to almost non accumulating snow for the CP if that happens.  It's definitely a tough call and I can see why the local mets are so gun-shy, it's such an unusual setup for big snows.

 

NOAA probably has it covered for now.  Any other event and people would be forecasting 8-12 or 10+ by now.  The Euro, the NAM (removing the 1 warm wedge that none of it's higher res subordinates have), the RGEM, GGEM, all the mesos support it.  Even the GFS is close.    I'd want to see one more run over the GFS and probably the Euro.  The Euro JMHO did make the normal move to slightly more progressive this run.  In the last 3 runs it went north then east.  Could be wobbles, could be the beginning of a move. 

 

The GFS has been so erratic it makes comparisons difficult.  I'd probably split the difference between the GFS and Euro at this stage.  that's still a lot of snow.

 

TBH I don't think the reason the TV crew was so cautious had much to do with rates. 

 

EDIT it should be noted all models that have a stronger s/w coming down out of Canada have a firehose in the middle 40-60 hours that the GFS does not.  The UK and GFS insist the s/w coming down is no big deal.  But they've been terrible so far in handling the features.

[Logan11]

Good thing Kevin slept through the Euro.

 

 

Looks solid here with the inverted trough on target though.

[Ji]

Where is my thread about how Boston gets snow From every possible scenario including a blocked mid Atlantic monster

[ORH_wxman]

Where is my thread about how Boston gets snow From every possible scenario including a blocked mid Atlantic monster

 

 

I didn't know you made one...enjoy your snow.

[ORH_wxman]

That firehose look on the Euro is great looking...if it held like that and didn't shift SE...I would back the QPF up further W too.

[Clinch Leatherwood]

That firehose look on the Euro is great looking...if it held like that and didn't shift SE...I would back the QPF up further W too.

 

Yeah exactly.  Same thing all the mesos were doing.   NCEP went with the 0z GFS/Euro blend...I kind of said the same thing but TBH looking at how bad the 18z to 0z GFS shifts were aloft I'm not sure one can justify it.  But, I suppose it's the safe play for now because what we may see compromise out later is the GFS stronger with the diving s/w but the Euro continue to be a wedge more progressive offshore...so it'll roughly even out. 

 

MODEL DIAGNOSTIC DISCUSSION

NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

133 AM EST WED MAR 06 2013

VALID MAR 06/0000 UTC THRU MAR 09/1200 UTC

...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR

INGEST...

...EVALUATION OF ALL AVAILABLE 00Z MODEL GUIDANCE INCLUDING FINAL

PREFERENCES/FCST CONFIDENCE...

ANY INITIALIZATION ERRORS WITH THE 00Z NAM WERE NOT DEEMED TO BE

SIGNIFICANT ENOUGH TO IMPACTS ITS FCST. MEANWHILE...THE 00Z GFS

SEEMS TO MISHANDLE THE MOISTURE CONTENT ACRS SRN FL AS IT COULD

NOT RESOLVE THE GRADIENT IN PWATS FROM TAMPA BAY TO MIAMI.

...STRENGTHENING CLOSED LOW MOVING FROM THE UPR TN VALLEY TOWARD

THE LWR MID-ATLC OVERNIGHT...

...LOW CENTER EVENTUALLY SHIFTING NEWRD JUST E OF COASTAL NEW

ENGLAND...

FINAL PREFERENCE/FCST CONFIDENCE: GENERAL MODEL COMPROMISE FOR THE

FIRST 24 HRS (HIGH CONFIDENCE)...THEREAFTER WILL FAVOR A COMBO OF

THE 00Z GFS/ECMWF (BELOW AVG CONFIDENCE)

A WELL DEVELOPED CYCLONE WHICH HAS ALREADY DROPPED ABUNDANT

SNOWFALL FROM THE NRN PLAINS/UPR MIDWEST DOWN THRU THE UPR GRT

LAKES WILL SLIDE S OF E TOWARD THE LWR MID-ATLC TNGT. AS THIS

OCCURS...THE SYSTEM SHOULD CONTINUE TO DEEPEN WITH WINTRY PCPN

EXPECTED ACRS THE REGION TONIGHT AND INTO WED. THIS

INTENSIFICATION PROCESS IS FCST TO INDUCE A DEEPENING SFC LOW

WHICH WILL TRACK FROM NC ACRS THE VA CAPES AND EVENTUALLY OUT TO

SEA. THEREAFTER...THIS DISTURBANCE SHOULD GRADUALLY MAKES IT WAY

TOWARD THE N AND E WITH SOME OF ITS PROGRESS BEING IMPEDED BY A

MID-LEVEL BLOCKING PATTERN TO THE N. OVERALL...THE 00Z/18Z NAM ARE

IN LINE AND JUST AHEAD OF THE 12Z RUN ON WED AS THE SYSTEM

STRADDLES THE NC/VA BORDER. MEANWHILE...THE 00Z GFS IS A HAIR

FASTER THAN ITS PREVIOUS RUNS EARLY ON. AS THE CLOSED LOW LIFTS E

OF 70E LONGITUDE...THE PAST FEW RUNS OF THE NAM SUGGEST THE

CYCLONE WILL NEARLY STALL GIVEN THE BLOCK IN PLACE. ONLY MINIMAL

RUN-TO-RUN DIFFERENCES WERE NOTED. ON THE OTHER HAND...DIFFERENCES

UPSTREAM LEAD TO THE 00Z GFS BEING FARTHER E THAN THE 18Z/12Z

RUNS. EARLY IN THE PERIOD...THE SUBTLE DIFFERENCES WHICH HAD

EARLIER APPEARED WERE RESOLVED AS THE 00Z CMC/UKMET CAME IN

STRONGER ALOFT MATCHING THE INTENSITY OF THE CONSENSUS SOLN. LATER

ON...THE GUIDANCE IS IN HALF-DECENT AGREEMENT AS THE UPR LOW

STALLS E OF THE 40N/70E BENCHMARK. WHILE THE CORE OF THE CYCLONE

STAYS E OF COASTAL NEW ENGLAND...THE NWRN EDGE OF THE CYCLONIC

CIRCULATION MAY IMPACT THE REGION. IT APPEARS THE 00Z/12Z UKMET

ARE A BIT QUICKER AT PUSHING THIS SYSTEM EWRD WHILE THE 21Z SREF

MEAN IS OFF TO THE W AS IT IS INFLUENCED BY A MORE PROGRESSIVE

UPSTREAM CYCLONE. FOR THE FIRST 24 HRS OF THE PERIOD...WILL FOLLOW

A GENERAL MODEL COMPROMISE GIVEN THE 00Z CMC/UKMET HAVE COME IN

LINE WITH OTHER MODELS.  LATER ON...GIVEN THE UPSTREAM INFLUENCES

OF THE UPR LOW CROSSING THE UPR MID-ATLC...WILL FAVOR A SOLN

SIMILAR TO THAT SYSTEM. THAT IS A COMBO OF THE 00Z GFS/ECWMF.

 

 

[Logan11]

Then how would you explain last winter when I guess they had less than 6 inches ..or was it less than 3 inches? 

 

Where is my thread about how Boston gets snow From every possible scenario including a blocked mid Atlantic monster

[joey2002]

That firehose look on the Euro is great looking...if it held like that and didn't shift SE...I would back the QPF up further W too.

 

Yeah, I'm sure we have lots of surprises in store over the next few days.

[N. OF PIKE]

is DC crew sleeping at all tonite

[Clinch Leatherwood]

Airport impact looks pretty significant?

[TheSnowman]

Well the water vapor imagery loop is Just about to start forming an eye. You can easily see. So feeling good this storm will have the Classic Historic Look. (Right in Southern WV)

[ORH_wxman]

Euro has sub-504 thicknesses by Mar 15th over the area with incoming powder clipper...slightly off topic but I'm posting it because about 6 of us are online here right now and its slow.

 

Spring Fling!!

[Logan11]

Off topic, but it's backing ridiculous cold into Europe also from Russia.  

 

It would be nice if the Monday system could trend  a little south..lots of cold just north as that approaches.

Euro has sub-504 thicknesses by Mar 15th over the area with incoming powder clipper...slightly off topic but I'm posting it because about 6 of us are online here right now and its slow.

 

Spring Fling!!

[Clinch Leatherwood]

Euro has sub-504 thicknesses by Mar 15th over the area with incoming powder clipper...slightly off topic but I'm posting it because about 6 of us are online here right now and its slow.

Spring Fling!!

That's pretty insane really. I'm glad Mother Nature needed a normal march.

[free_man]

Euro has sub-504 thicknesses by Mar 15th over the area with incoming powder clipper...slightly off topic but I'm posting it because about 6 of us are online here right now and its slow.

 

Spring Fling!!

I'm looking at the free euro now,  it looks better than most patterns we get in the winter.   Schweet.

[eduggs]

EDIT it should be noted all models that have a stronger s/w coming down out of Canada have a firehose in the middle 40-60 hours that the GFS does not.  The UK and GFS insist the s/w coming down is no big deal.  But they've been terrible so far in handling the features.

I definitely see your point.  But I still think you overstate the differences.  To my eye, the moisture train on the GFS 700mb and 850mb panels looks basically similar to the Euro "firehouse," just toned down.  We might even call the GFS a firehose if we were not comparing to 3" solutions.  I think it's an unjustified presumption that we can deduce the cause of the QPF differences based on a visual analysis of graphical charts.  The processes at work require supercomputers to resolve.  It could just be a simple model phsyics issue.  I think the GFS is too light with QPF, but primarily because it's the driest outlier.  And the GEFS are dreadfully boring with QPF. 

[Clinch Leatherwood]

Well...I'm not sure how they can come on air in a few hours with slushy snow showers in the CP.

Gfs mirrors noaa, the euro is probably 1-2 feet, 4km nam the same, ggem 8-12" or better, etc etc. this may still dovetail some SE but a lot of snow should fall just in the first burst that lasts 6-15 hours. Even the gfs supports some insane snow rates. The difference between nice and historic comes after that first dump anyway.

[ORH_wxman]

That's pretty insane really. I'm glad Mother Nature needed a normal march.

 

 

We haven't had many cold ones recently, and its unclear if this one will even qualify when its over. Cold winters (and esp Marches) are hard to come by these days in our region of the world since about 2005....yet they are getting absolutely brutalized in Europe and Asia recently. When the pendulum flips back, I'm sure people will be shocked...but maybe we are just in a tough spot for them until further notice due to climate change and sea ice forcing the blocking pattern to favor the other side of the pole where all the cold has been recently...but that speculation on cause/effect is really a topic for the climate change forum...but its always fascinating to me how we sometimes go through these stretches where the weather seems to repeat itself

[Logan11]

Good that it looks like we banish Morch to the dustbin this year.

 

Now what I want is a big early season cold/snowy pattern starting in November like the old days. I'm sick of pissing away the first month of met winter.  Maybe we can go six months from last snow to first snow.

I'm looking at the free euro now,  it looks better than most patterns we get in the winter.   Schweet.

[Logan11]

Hah well taken verbatim there is a just a tad bit of difference around here with the GFS .35" qpf and the NAM's 1.6"! I think the GGEM is like .8" But yeah I see your broader point.

I definitely see your point. But I still think you overstate the differences. To my eye, the moisture train on the GFS 700mb and 850mb panels looks basically similar to the Euro "firehouse," just toned down. We might even call the GFS a firehose if we were not comparing to 3" solutions. I think it's an unjustified presumption that we can deduce the cause of the QPF differences based on a visual analysis of graphical charts. The processes at work require supercomputers to resolve. It could just be a simple model phsyics issue. I think the GFS is too light with QPF, but primarily because it's the driest outlier. And the GEFS are dreadfully boring with QPF.