So About Next Week…

Tonight's 00Z European Model Forecast for Next Wednesday Evening (http://www.meteo.psu.edu/~gadomski)

I’m not one to go bonkers when it comes to any particular storm (in fact, you read me discussing how I would be apt to NOT hype next week a couple days ago). But I think now it’s obvious we have something rather significant showing up here. The three major models tonight all went nuts for the middle of next week, showing an absolutely massive storm slowly rolling up the East Coast. When all three models lock in on a massive storm, that very often means that they’re right. Models struggle and they can be a bit inconsistent at times, but when it comes to the extremely large, widespread or historic sized events, they are usually quick to hit on things. I’m not saying that next week’s storm will be historic, but there’s no question we’re now looking at a significant to major event for much of the Mid-Atlantic and Northeast.

Tonight's 00Z GFS Model Forecast for Next Wednesday Evening (http://www.meteo.psu.edu/~gadomski)

So what are the details? Well, it’s far too early to speculate, but we’ll do just that because we can. Based on tonight’s model runs, we’d be looking at a snow to mix/rain ending as snow event from I-95 to the coast (and even a little further inland from there), with extremely heavy snow/mix possible from the Smokeys north into Upstate NY and interior New England. The storm is also extremely slow moving. For example, the precip begins in Philly on tonight’s Euro run at about Midnight Wednesday and does not end until about 9-11 AM Thursday. Snow moves into the Albany area around 9 AM Wednesday and doesn’t depart until after Noon on Thursday. These aren’t forecasts…they’re just examples of what the model is showing and emphasis on a 24+ hour event.

Tonight's 00Z Canadian Model Forecast for Next Wednesday Evening (http://www.meteo.psu.edu/~gadomski)

The other issue then is track. Tonight’s runs are up along or just inland from the coast. That is extremely unfavorable for heavy snow from DC-Boston…that’s a wet track, not a white one. However, if you look closely at each model’s ensemble mean, you’ll see the track is still fairly far offshore. What does this mean? That the operational models *may* be on the extreme west edge of the track forecast envelope. I wouldn’t go shouting from the rooftops just yet, but it’s something to keep in mind.

We’ve seen a lot of storms the last couple winters, but this one I think is the most impressive looking in terms of physical size and slow track. We’re in a powder keg pattern right now, and this may be the fuse that helps things explode. I’m not going to get into details of the meteorology behind what’s happening right now, but we need to watch things very closely over the next few days. But each model run has looked more impressive with this storm, not less impressive, and that trend may continue as we get closer.

Unfortunately, I’m heading out of town Friday afternoon…well, actually I’m moving, but taking a week or so to drive to Texas, so my updates will be much more infrequent. However, make sure you “like” State of Occlusion on Facebook, as I’ll post updates each night/morning with the latest information. This really could be a big time event, so stay tuned!

What 2 Watch 4

Watching the Onion Sports Dome tonight, so there’s a play on SportsCenter. A couple things to watch. As the annoying snow/ice/sleet/rain storm exits the Northeast tonight, attention focuses on the next two systems. The first one looks to bring a quick hitting shot of snow in a couple days, followed by a much stronger and larger system next week, who’s ultimate fate remains to be seen.

GFS Forecast for Friday Morning, credit: PSU E-Wall (http://www.meteo.psu.edu/~gadomski)

A very quick moving system will swing through the Mid-Atlantic and Northeast Thursday night and exiting Friday afternoon. The map to the left shows the GFS forecast for Friday morning, which has a pocket of moderate to heavy precip in Central Jersey and just south of Long Island. This is a pretty cut and dry situation, with the system sliding through. The only final question is on track. Once that’s in line, we can pin down amounts and locations. Right now it appears that there will be a solid stripe of 2-4″, surrounded by lighter amounts. At this point, the models pin it north of the Mason-Dixon Line and northwest of I-95. So Philly-NYC expect roughly 2-4″ right now. There is the chance it could be closer to 5-6″ in spots, but this will not be a major storm. Then, as the storm blows up exiting the New England coastal region, we could see some heavy snow fly back toward Boston and Eastern Massachusetts. I wouldn’t be shocked to see higher amounts there. Heavy snow will also fall in western Maryland and western PA and parts of WV.

Now heading into next week, the models continue to advertise a significant East Coast event. I’m not entirely convinced this will be a big snow event for anyone in particular. The three main models (Canadian, American, and European) all show the storm. The GFS is a little more suppressed, which isn’t abnormal. So it would just be a mild snow event. The European and Canadian models are much stronger and hug the coast. So what we have here is a situation. We’re a week away and we have a storm showing up, and it could be potentially strong. We’ve got it showing up a little further west than more recent big snow events on the whole. And we have disagreements on overall track.

So, I’ve gotten a lot of questions about next week. The bottom line: Way too far out to hype this thing. It could do any number of things. It could be snow, it could be rain, it could be a mix, it could be nothing. So stay tuned!

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State of Occlusion is on Facebook! I’ll post some additional cool links, quick model status updates, and snow maps early on that page. “Like” the blog by clicking here!

It’s a Christmas Miracle? Flip a Coin.

Just a quick update. I won’t be drawing a snow map this evening for a couple of reasons: One, it’s Christmas Eve, two, the Euro won’t be out for another hour+, and three, the amount of inconsistency and volatility regarding this storm is something I’ve heard people with years of forecasting experience beyond my own, say they have never ever witnessed. In other words: You’re looking at one of the most complex storm systems we’ve ever seen…moreso because of the location it may or may not impact rather than because of the storm itself.

But I will provide you with a couple of major teases. The two maps I place at the end of this entry are raw snowfall forecasts from the GFS and NAM computer models from this evening. Now, don’t go shouting from the rooftops. I STILL am not behind this storm. I still see flaws. I still think the models are suffering problems (given their wild swings and disagreements over the last 2-4 days or so, this may seem obvious). And I still think we’re in for changes here in the final 36-48 hours before gametime. The Hydrometeorological Prediction Center’s model discussion this evening is once again hinting at the potential that the models are erring, and that could be leading to solutions later in their runs that are, well, incorrect.

CONSOLIDATING UPPER LOW OVER THE EAST...
LOW PRESSURE FORMING UP THE EAST COAST...PREFERENCE FOR A 00Z
NAM/15Z SREF MEAN COMPROMISE
THERE ARE SMALL SCALE DETAILS THE NAM/GFS/ECWMF ARE SHOWING ISSUES
WITH WHICH MAY IMPACT ITS FORECAST LATER ON.  THEIR SOUTHERN
STREAM SHORTWAVE IN TEXAS ARE 30-40 METERS TOO WEAK AT THE 500 HPA
LEVEL BASED ON RAOB REPORTS FROM TEXAS.  THE NAM DOES NOT CAPTURE
THE ONGOING CONVECTION IN EASTERN TEXAS.  THE 18Z AND 00Z GFS RUNS
ARE SHOWING SIGNS OF CONVECTIVE/GRIDSCALE FEEDBACK AS THE SYSTEM
MOVES ALONG THE GULF COAST WHICH COULD BE MAKING ITS SOLUTION AT
THE SURFACE AND ALOFT TOO STRONG.  THERE ARE HINTS THAT THE RIDGE
INITIALLY ALONG THE EAST COAST IS MORE AMPLIFIED THAN THE
NAM...WHICH WOULD BE CLOSEST TO THE 12Z ECMWF/12Z ECMWF ENSEMBLE
MEAN FORECASTS FOR 00Z.  ANY OF THESE DETAILS COULD
DEGRADE/NEGATIVELY AFFECT THE SHORT RANGE FORECAST.

So there’s still much uncertainty. I mean, honestly, there’s NO forecast out there now that stands much chance of being right on, including my own. This is simply one of those storms where you sit back, roll the dice, and pray you come close.

Consider a compromise of the maps below as the potential for the maximum impact of this storm. Click on either map to enlarge it. Consider my forecast map from earlier this morning the potential for minimum impact of this storm. So enjoy the tease, because tomorrow is going to tell us that either a hefty dose of reality is going to kick in, or you really will believe in miracles. Merry Christmas!

00Z NAM Forecast Snow: http://wxcaster4.com (Worth bookmarking)
00Z GFS Forecast Snowfall: http://wxcaster4.com

Tomas & Haiti? Plus Storm, Heat, and MeteoPolitics!

Wind shear and 24 hour change in the Atlantic Basin, credit: University of Wisconsin CIMMS

Tomas continues along in the Caribbean today, about 265 miles west of St. Lucia, chugging off slightly north of due west around 10 mph. Tomas bumped up to a Cat 2 storm overnight, but has since weakened, back to a minimal 75 mph category one storm. Reconnaissance aircraft visited the storm earlier and helped quantify what satellite had been showing all day. It looks pretty ragged, as some dry air and shear have begun to take their toll on Tomas. You can see  the ragged structure of Tomas here. The darker area to the west of the storm indicates the presence of at least some drier air too. The image to the left shows the current wind shear analysis in the Atlantic, as well as the trend. The red area near the hurricane symbol indicates that Tomas is in an area of enhanced shear. Assuming things gradually progress from west to east, it would appear things are only going to get more hostile for Tomas the next day or so. In fact, the model guidance suggests that the shear remains over Tomas into Tuesday, before pulling away. Provided Tomas can maintain its core and overall structure, even if it weakens into, say, a tropical storm, it will have an opportunity later Tuesday and through Wednesday to intensify, and given the water temperatures in that region, it could be explosive strengthening if the conditions are right.

In terms of the track of Tomas, while things may change some in the next day or two as the storm fluctuates in intensity,

Morning Model Guidance Spaghetti Plot of Tomas' Tracks, credit: South Florida Water Management District

you can see that most of the models track Tomas to just south of Hispaniola. After that, they generally either stall or it lift it northward. In reality, given the normal uncertainty of tropical systems, anything is possible, from Cuba to east of the Dominican Republica. Unfortunately though, Haiti looks to be right in the middle of the possibilities. And again, unfortunately, regardless of the intensity of Tomas at landfall, this is really looking like it could be a very grim situation for that country, and if you thought things couldn’t get worse in Haiti, this would be how it can. Current model projections (which generally do a poor job handling specifics of tropical system precipitation totals) are dropping 8-10″ on southern Haiti. This is really a disheartening situation to watch, and hopefully precautions are already being taken to ensure the safety of residents and relief workers.

Elsewhere…

Still watching this storm for next week. In my forecasting for California next week, it was pretty obvious the differences in the main models (Euro and GFS). The GFS cuts down the western ridge and slides it to the Lee of the Rockies on Friday/Saturday, which has almost no support from any other model or its own ensemble members.

Euro Depiction of a Mess in the East, credit: Allan Huffman's Weather Model Page: http://raleighwx.easternuswx.com/

So what it’s doing is forcing everything in the east to develop further east, and therefore not as amplified. The Euro however last night took a deeper low out of the gulf and up the Appalachians into Western NY, wrapping the possibility of at least a few inches of snow on the backside for much of the mountains of Tennessee/North Carolina, up through West Virginia, eastern Ohio, western PA, Michigan, and western NY and Ontario, along with some lake effect or lake enhanced snow on the wrap around. The European has some support from the Canadian model (which is taking a 980 mb landbomb from the Carolinas northwest into OH/IN), which is also encouraging for confidence. This morning’s verison of the Euro was a little further east, and brought the chances for snow from the mountains of NC/TN up through WV’s mountains, and perhaps some in W PA and Eastern Ohio/Western NY, as well as Ontario and northern Michigan. It has to hit a fairly narrow window for snow, but if I had to place bets right now, I’d lean on Ontario/Michigan and not much more than that at the moment. Stay tuned.

Election Day Weather

With the big midterm elections coming up, there are all sorts of anecdotes about weather and people’s voting habits. Well, we’ll test the theory again this year, but primarily in the south. It looks like areas from Houston to New Orleans up through Mississippi and into Memphis and over to Little Rock will see the worst weather in the US on Election Day (as the late week storm begins to develop). Otherwise, other than a couple showers in the Northwest and parts of Minnesota it looks dry. So no excuses to stay home…go vote.

Cali Heat

I discussed how the European model keeps the western ridge in tact. Well that ridge is going to lead to searing autumn heat in California, with Santa Ana winds possibly leading to temperatures into the mid or upper 90s here in SoCal. It looks blazing hot Tuesday and Wednesday. Tuesday’s record high for Downtown LA is 99 degrees, and Wednesday’s is 95 degrees. Tuesday’s looks a lot safer than Wednesday’s at the moment. I suspect we could be talking record heat for a day or two in parts of SoCal. Been a year of some ridiculous temperature extremes out here.

 

Twin Tropical Trouble + Latest on Next Week

European Model Surface Plots (Left: Thursday morning, Right: Friday morning), From PSU E-Wall.

Not too much to add this afternoon on next week’s eastern system. There are still glaring differences between the models. The European model continues to go all bomb’s away off the East Coast. The GFS model continues to be flat..dumps some pretty chilly air in, but no storm. I continue to side with the Euro for the most part on this, with maybe not as much of an explosive system to develop later next week. Check this out. The European model (images above) takes the storm from about a 1008 mb weak low on the Carolina coast Thursday morning to a 972 mb beast in Central Maine on Friday morning. One key change with the European model today though is that it is not flinging quite as much moisture back into the cold air on the west side of the storm. This would spell less snow, except perhaps for the higher terrain of Northern New England (which would be hammered if the European model is correct).

So the take home message today is that, there’s still a chance for a pretty interesting storm. There’s a chance snow will be involved in some interior sections. There’s also a slight chance we could be dealing with another bomb cyclone, which could potentially cause significant weather impacts in parts of Northern New England and Quebec. So stay tuned…these sorts of battles aren’t uncommon between the two models. This will be a good test for the upcoming winter. Sometimes if a model shows a radical solution (like the Euro) and ends up correct, you can occasionally give that model some extra confidence through the winter season. In a tough situation, sometimes that can pay off huge if you’re a forecaster. So we will see.

In other news….

Model Spaghetti plot of tracks for Tropical Storm Shary, from South Florida Water Management District

The National Hurricane Center has started issuing advisories on two new tropical systems in the last 24 hours: Shary and Tomas. This brings the 2010 Atlantic Hurricane Season tally to: 19 named storms, 10 hurricanes, and 5 major hurricanes. Normal is 11/6/2 I believe. So we’re long gone in terms of normal.

So what about these two storms? Shary is more of a nuisance than anything. Expecting a mid-grade tropical storm (current winds 60 mph) that will bring gusty winds and locally heavy rain to Bermuda. Then it should scoot out to sea.

Tomas, on the other hand, has a potentially much more sinister future ahead. Tomas just formed, so its winds are only 40 mph, and it will scoot along in the Caribbean, likely not impacting anyone through the weekend (except perhaps some cruises or some outer rain bands/gusty winds on some of the islands). But Tomas is headed into an area of very favorable ocean and environmental conditions for development.

Model Spaghetti plot of tracks for Tropical Storm Tomas from South Florida Water Management District

The latest image from the LSU Earth Scan Lab shows a whole lotta red in the Caribbean. This spells development if the environmental conditions are right. And it appears they will be as we go into next week. The official track of Tomas from the NHC shows it becoming a major hurricane next week as it begins to turn north toward, sadly, Haiti. If there is one place in the Atlantic Basin that could really use a season without a direct impact from a storm, it’s Haiti. Still a long way to go, but this could very well shape up to be a devastating storm for someone. We’ll see.

More Power/Less Power

Some renewable energy news to close things out.

California is fast tracking several big time solar plants to get in before a critical deadline.

Wind power, however, has slowed down considerably, back to 2007 levels. I do think wind will pick back up with the economy though.

More later…

Intriguing Scenario Next Week, Video of a Tennessee Tornado, and More

Looking ahead, we might have some interesting weather on the horizon around or just after Election Day. Both of the main models we assess…the GFS (American model) and ECMWF (European model) are suggesting low pressure to develop in the East early to middle next week. But, the models disagree on exactly how things are going to pan out. The GFS is a little flatter and slower with the system, which means it doesn’t draw in nearly the same amount of cold air, and doesn’t really deepen the storm as much. The European model is much deeper and is enough to draw in cold air and flip rain to snow over many interior locations (well west of I-95 and the Big Cities).

Wednesday Morning's European Model 500 mb Forecast
Wednesday Morning's GFS 500 mb Forecast

So at left, I’ve posted both 500 mb (maps of what’s happening about 20,000 feet up) maps for next Wednesday morning. And I think one of the keys is what’s happening out west. If you notice, the Euro (left) paints a fairly robust ridge of high pressure over the West (which is going to create significant heat for California and the interior for the first half of next week). If you compare that to the GFS (right), the ridge is a little skinnier, tilted northeast, weaker and slightly further east (and also has a much broader upper low centered over Texas, Arkansas, and Louisiana).

A good rule of thumb for those of you in the east is that if there is a Western ridge centered around the same longitude as Boise, ID, that’s a favorable position for getting interior snow and a decent East Coast storm. The Euro has that; the GFS does not. So which model is right? Generally, this far out, you put your money on the European model. My philosophy when forecasting for California today was that the Euro had the right idea (though not quite AS aggressive as the model is showing) and the GFS broke the western ridge down too quickly. If you look at the ensembles (each model has a set of similar models run with different conditions to provide a forecast blend), you’ll clearly see that the Euro is a little too aggressive with this ridge in the West, and the average falls somewhere between it and the GFS solution.

So my current thinking? Rain, maybe ending as snow for interior locations like Syracuse, State College, and much of West Virginia. If the Euro is right, we will be talking about some accumulating snow in interior parts of New York, Pennsylvania and the mountains of WV and MD. If the GFS is right, don’t expect much. I’ll watch it evolve and post more as we get closer.

More on the Midwest Storm

A good article from WLFI in Lafayette, IN summing up the damage in their viewing area. Some good pictures and details here.

Stu Ostro of The Weather Channel, as always, has a great write up putting the storm in some historical context…in that, while it was a really, really strong, epic storm…it really lacked some of the features of those truly epic storms of the past. The reason? Well, I’ll let him explain.

A couple of fantastic NWS post-mortems with great imagery and details: Duluth, MN and Grand Forks, ND

Bonus video: Surveillance footage of a tornado near a dam outside Chattanooga, TN.

And I’m not 100% sure if this is included in the above, but this is absolutely ridiculous footage of that tornado (I think), destroying trailers. Incredible…and scary.

Other Links

Speaking of The Weather Channel, it sounds like they’re backpedaling somewhat from their comments about going away from weather only programming.

It’s been a year of extremes nationally, but looking at it more locally, it’s been a rather incredible year in Baltimore, MD.

The Washington Post reports on the last home on a sinking Chesapeake Bay island that has collapsed. A rather interesting read.