Saturday, March 1, 2014

Unbroken

UNBROKEN
(FACEBOOK STATUS UPDATE FROM OLD MAN WINTER, 
WHEN THE PROGRAM ASKED, "HOW ARE YOU FEELING TODAY?")


  • SIGNIFICANT MULTI-DAY, COAST-TO-COAST WINTER PRECIPITATION EVENT NOW UNDERWAY AS ARCTIC FRONT PRESSES SOUTH & EAST. 
  • TEMPS DURING STORM DROP TO SINGLE DIGITS IN OHIO VALLEY AND INTO THE TEENS FOR MID-ATLANTIC AND NORTHEAST


EARLIER, WINTER STORM WATCHES AND WARNINGS STRETCHED FROM 
U.S. ATLANTIC COAST TO NORTHERN CASCADES OF WASHINGTON STATE



6:50 PM 3/1 (Winter Stormcast Team) Earlier today, we chose not to wish you a "Good First Morning" of March, because there was nothing good about the enclosed NWS watch/warning map. 
A basic guide to how we think this storm will play out as it marches East: Expect similar amounts of snowfall or sleet/freezing rain as you received in the February 13-14 Event. For the Mid-Atlantic, below are the two projected scenarios we see at this time. We are adding additional text to the report to qualify the 40% vs. 60% situations. We are also currently finalizing a new snowfall map for the region, to be posted between 8 and 9 PM EST.


NARROWING THE OPTIONS
Our Winter Stormcast Team often refers to a set of factors that influence storm track and eventual results. The TV weather community does as well, but this storm situation provides an excellent opportunity to explain the science BEHIND what drives an outcome like Scenario B to have greater probability in our projection. 
  • SCENARIO A (All Precip Types Ahead) - Due to a more southward pressing Arctic High pressure building in from the Northwest territories (of Canada!), we project a 40% probability that cold air will remain in place across much of the storm track. A northeast fetch of wind ahead of low pressure waves along a front will convert moisture to snow overnight Sunday, but also lead to an expansive area of freezing rain for a large portion of the central and eastern U.S., then changing to heavy wet snow overnight into Monday. The I-95 corridor would see most known precipitation types in this setup, from rain to sleet to freezing rain to snow, and yes perhaps even our old friend GRAUPEL!
  • SCENARIO B (The Big SnowBomb) - Were the southern low pressure waves to travel ever further south and east toward the coast, the area of heavy snow could easily spread over the major cities and coastal communities of the Mid-Atlantic and Northeast. With liquid equivalents of 1.00"+ and ratios of 15:1 inland and 10:1 near the coast, snowfall could rival what was observed in the Feb 13-14 event. We have assigned a 60% chance of this scenario given the most current information available. 

WHY COULD THIS TURN INTO A SNOWBOMB? It's all about the O- as in the NAO. The North Atlantic Oscillation is key large scale air pressure force that can strongly influence the outcome of storm tracks through the Eastern U.S. If the NAO is trending DOWNWARD (or mimicking a trend toward neutral), that means a fresh press of Arctic Air can push southward and edge a storm track a few miles more out to sea. The effect is that more Atlantic moisture can be tapped and wrapped back around over the coast and inland areas... hence you get a much snowier situation than first expected. This link to a research page at Columbia University provides a detailed look at the various teleconnections our team uses to track complex storm patterns 





For a full overview of our previous scenarios can be seen in the report posted on 2/28

LATEST ANALYSIS RESOURCES

36 comments:

NeedaSnowday said...

Funny Tina!

Here is Morph ....http://darthdev.deviantart.com/art/snow-fist-356975772

Andy, Southern York County Pa said...

Statement as of 3:23 AM EST on March 01, 2014

... Winter Storm Watch in effect from Sunday evening through
Monday afternoon...

The National Weather Service in Baltimore MD/Washington has
issued a Winter Storm Watch... which is in effect from Sunday
evening through Monday afternoon.

* Precipitation type... freezing rain... sleet... and snow.

* Accumulations... potential for freezing rain followed by five or
more inches of snow.

* Timing... freezing rain and sleet looks to begin Sunday evening
changing to snow... heavy at times... overnight Sunday through
Monday.

* Temperatures... in the lower 30s Sunday evening... mid 20s through
Monday.

* Winds... north 5 to 15 mph with gusts up to 25 mph.

* Impacts... potential for hazardous travel Sunday evening from
icy roads... becoming snowy for Monday.

Precautionary/preparedness actions...

A Winter Storm Watch means there is a potential for significant
snow... sleet... and ice accumulations that may impact travel.
Continue to monitor the latest forecasts.

Andy, Southern York County Pa said...

Statement as of 3:33 AM EST on March 01, 2014

... Winter Storm Watch in effect from Sunday afternoon through
Monday afternoon...

The National Weather Service in State College has issued a Winter
Storm Watch... which is in effect from Sunday afternoon through
Monday afternoon.

* Snow accumulations... potential for 6 inches or more.

* Timing... the period of heaviest snow and significant
accumulation from Sunday night through Monday morning.

* Impacts... dangerous travel conditions due to snow covered roads
and reduced visibility. The Monday morning commute may be
significantly impacted.

Precautionary/preparedness actions...

A Winter Storm Watch means there is the potential for significant
snow... sleet... or ice accumulations that may impact travel. For
the latest weather information... go to weather.Gov/ctp or stay
tuned to NOAA Weather Radio.

Tara said...

Two weather alerts with different snow totals? I'm confused. 5 inches for Balt/Wash but more elsewhere? Someone decode please!

Tara said...

Oh... It appears all of this just went up and more info is coming. Nevermind!

Baltimore Ravens champ 1015 said...

Tara, one is for Balt/Wash and the other is State College, pa

Christian Walker said...

However, when the winter storm warning is issued, either tonight or tomorrow, NWS will provide a more defined range....

Andy, Southern York County Pa said...

One thing to take into account when looking at QPF and snow maps is that ratios will be above to considerably above the normal 10:1 ratios at which maps are created. I could see most of this region averaging 15:1 ratios. QPF is generally 1.0-1.2 inches in Baltimore metro through rt 30 in York County PA. What that means with those kind of ratios is a "GENERAL" 15 inch snow. I think it is fair to say that most of us from southern York, Adams, Lancaster counties down through Baltimore, Washington, to Annapolis are looking at a GENERAL 12-18 inch type snow. The will be banding etc that will create localized higher totals.

I had a hunch that this storm would not be a rain or ice storm because of the way the PV has been modeled in past events. It has almost always trended stronger and cold has been a winner this year.

Once it started to go that way again I knew there was likely no return. So I was more comfortable with the general notion of 8-12, with 12-16 north and west of Baltimore for the last day to day and 1/2 and threw it out there as the general idea.

Now that the general idea has SOLID support we can start to fine tune things a little.

I think the Eastern shore gets in on the fun here as well. Foot's forecast will issue maps as time goes on and they do a GREAT job breaking things down. I use the Rich Foot method of looking at storms, and conducting "storm investigations".

This has been a great year to track and a winter that keeps on giving. For all of us who have not been involuntarily committed by Court order to insane asylums and love storms, no better place than here on Foot's Forecast in my book!

People take weather too seriously, but luckily we don't here, we just try to figure out what's coming our way.

Tara said...

Ah State College, I thought that was somewhere near Towson, MD or something.

I do not come out from under my rock very often. My apologize!

Unknown said...

You guys at Foots continue to do a fantastic job.

NeedaSnowday said...
This comment has been removed by the author.
NeedaSnowday said...

Morph gets NAM'd.... That fuscia color looks good on you!

http://forums.accuweather.com/index.php?act=attach&type=post&id=230264

ravensbbr said...

I think we need to organize a Foot Clan sledding meetup of the regulars on this board somewhere...thoughts?

Darin, Columbia Md. said...

Thank you Andy that information was very helpful. I have lurked here all winter and I always come to read your forecasts.

Butch Dynomite said...

Great job footies ! I am learning and appriciative. Go snow!

Morpheus, Bowie MD said...

Hey Needa. I sure hope my area gets NAM'd or slammed, muffling my shouts of RAIN...I am still worried about temps on sunday of ~50 degrees??? Has plenty of precip. In previous storms, just the wrong type. I was a bit sad to read this on the foots page "Expect similar amounts of snowfall or sleet/freezing rain as you received in the February 13-14 Event." Translation 4 inches. :-(

BioPat said...

Apparently Sunday night when temps start falling we'll see the onset as rain, but Monday should be an all heavy snow event with temps bombing out as the snow falls so will the temps or vice versa.

NeedaSnowday said...

Very cool.... Nice work JB!!

http://m.youtube.com/watch?a=&v=5lKeDJJBmKw&feature=youtu.be

Morpheus, Bowie MD said...

BP - Yes it looks that way and it seems with such a complex setup, as other have explained well, only time will tell where the ptype line will setup initially and how long it take for the pvortex/storm strengthening to push south.
To be honest it is great to be discussing a potential high impact event this late in the year considering the past few years...so I am happily waiting to see how things shake out. Its been great to have fellow foot's followers cheering on snow for the lowlands! Thanks you all.

NeedaSnowday said...

http://m.youtube.com/watch?v=_ojZxCNT8M4

JB shows potential for a lil disturbance on Thursday....

Unknown said...

The 18z NAM gives anyone north of Baltimore about 2"...it was preaching closer it a foot a number of runs before. Geez...these things are trash.

Julee said...

My NPR station just reported a "total of 3 inches after this whole thing winds down."
THREE inches? THREE INCHES????????

Unknown said...

I'm gonna be pissed if this misses us I want a foot or more let's go snow for everyone. Andy any new thoughts to add.

NeedaSnowday said...

http://www.erh.noaa.gov/lwx/winter/images/StormTotalSnowRange.png

Perryhallpowderhound said...

Some folks may be mixing up total precipitation with actual snow totals. We are gonna get a good dose of old man winter's beautiful white tears.

Tina said...

Well, holy heck! Have spent quality time at that canine ER dealing with a dog that thought putting a nail through her foot would be a good idea. Silly dog. :((

In the meantime, apparently, lower DE has gone from 0 to 60, er, 3" to MAYBE 10"!!!

Tina said...

My 10+ possibility came from the NWS site, not JB. Who has us at a piddly 2+ish.

My nerves, my NERVES!!!

Morpheus, Bowie MD said...

Exciting, no? Well Acu met was saying that he feels the models are overshooting the southern track...so us lowlanders hang in the balance. I think we need the blocking or is it steering (perhaps I am mixing this up) - Andy have you seen your scantily clad, voluptuous friend?

Andy, Southern York County Pa said...

Too much reliance on model runs jumping back and forth with the strength of the confluence created by the PV. I like the general idea of what we have been talking about and we will fine tune numbers Sunday afternoon. Baltimore metro is in for 8-12, and 12-16 just to the north is a reasonable idea.

Remember if you are learning to read models or following the interpretation of models by others, that models are not forecasts, but forecasting tools.

Models have a nasty tendency to consolidate precip shields closer to the center of a low pressure system. Precip shields generally are more expansive then modeled come game time. The final analysis depends on the exact track, but factoring model performance, climatology, ratios, and regional topography, gives you a sense of what is the most likely scenario based on all reliable numerical guidance.

If there is some TITANIC change in the general idea overnight that would alter these general numbers we will jump on that. I have seen no titanic shift that would lend any credibility to a change in the general idea of this storm.

The 0Z runs tonight should give us a better idea of the exact track of the lp waves as they traverse the boundary, as well as the strength and placement of the PV.

In the meantime, go to the liquor store, lingerie shop for the girlfriend (just don't let the wife know), and hug your favorite model (numerical of course), we have a MAJOR SNOW STORM FOR MARCH on the doorstep, and if you love snow you will be very happy Monday.

NeedaSnowday said...

Okay, I'm totally puzzled and baffled by people that follow Justin Berk only to complain about snow?!? I guess the main purpose for following is find out about springtime showers, summer heat and humidity, and hurricanes, yes?

Powderhound's are excited about what's potentially coming ...I'm just not sure why you would choose follow a meteorologist and then whine and complain about the fact that we're going to get snow ....you live in Maryland for crying out loud, not Florida....

::: walks away shakin her head ::: do they not care about Morph??

Tina said...

GettingaSnowday... sing it!! Did you see the person last week who complained that all he (and the site) did was talk about weather???!!!

W.T.H???

Julee said...

Needy - once again, hitting nail on head.

Yesterday people were asking me about this site and what was predicted. As soon as I said 8 - 12 inches, the reaction was an annoyed, "Oh, COME ON!" -- as though I had specifically ignored their request for 75 and sunny. Finally, I just started handing out the web address and told them to check for themselves.

Cathy in BelAir said...

Needy and Tina,
I feel the same way about anyone who complains about the weather around them! If southern California doesn't like sun and heat....MOVE, if the Midwest isn't aware that there is a possibility of tornados.....MOVE, if southern states aren't prepared for the possibilities of hurricanes.....MOVE, - and so on. Some of this is catastrophic weather and can cause loss of life and destruction of property, and for that I do feel for them, but we're talking about snow here! Get food in and grab a good book and wait it out! If youre not a powder hound, thats OK, but this is the weather where you choose to live, settle down and get a grip!

BioPat said...

I have to admit the excitement in the anticipation of a good storm rivals waiting for Santa, why is it some of us just revel in a good old SNOW DAY! I am so looking forward to waiting for the first snowflake early Monday morning.

Anonymous said...

I worry it isn't going to happen.

Unknown said...

We are seeing rain in Westminster, MD