Vendor Forecast Discussion

[uncle W]

I mentioned 1971 the other day...JB's stealing my analogs... ...NYC got 1.35" of precipitation and a trace of snow...Temperature the morning of the event was 26...By the time the precip started temps were above freezing...Albany N.Y. recieved 22.5"...

[ChescoWx]

Dave T at Wxrisk on FB just said "As much as I would love to see a snowstorm in VA and NC from a 2nd low on Thanksgiving - even though this is what the 12z GFS is showing - I cannot in good conscience support this ridiculous idea - Keep in mind this is the 8th consecutive model run of the operational GFS and every single run has been vastly different from anything else. At least the Euro model has CONSISTENCY with it's solutions something the wretchedly awful GFS seems utterly incapable of"

 

He does make you laugh with his bluntness...

[ChescoWx]

Paraphrasing from JBs midday update today - He has no change to his ideas of a New Orleans to Norfolk to Nova Scotia track of the storm in the Tuesday-Thursday period. The GFS is likely having major problems with feedback and the handling of the two different streams. JBs main reasons to believe the storm will run the coast is the pattern and time of the year. The water off the east coast is very warm, and the trough is back in the Gulf of Alaska. So you have the GFS at 96 hours with too much of the northern branch in front, suppressing the flow and causing the southern branch energy to stream out in front of the main max. So the GFS looks like it is once again in its usual error mode. He goes on to mention given this overall pattern next few weeks, its time to hoist the Weatherbell winter storm flag! The pattern is a good one setting up for those who like winter weather. He also says any warm December forecasts will fall the way of the warm November forecasts.

[ChescoWx]

Paraphrasing from JBs midday post today - The storm will hug the coast to around Norfolk, then move up into New England. While he may have to adjust the track a bit west at the end, he thinks the rain cooled air in the coastal plain and the very warm water sitting offshore will provide the boundary for the storm to run along Wednesday a thermally induced ridge will develop over the piedmont and the storm comes up east of that and deepens. It emphasized again that this is NOT AND NEVER HAS BEEN A BIG CITY SNOWSTORM! He does think it will try to end as snow, perhaps even sticking, but its always been a storm targeted further west. He mentioned his post earlier last week that had the 1938,1971,1989 Thanksgiving events analogs and he said then that this looked more like 71.

[ChescoWx]

JB paraphrasing from this AM - interesting read on his take on how cold he sees it getting over the next month. He likes a blend of the NAM and ECWMF for the storm, He still thinks this will end as snow in the big cities, though the 1.5 to 2.5 inches of rain before hand is the big deal. He goes on to take a swing at the GW crew and Al Roker saying - nice , a guy that had no idea last week at this time this storm was coming and  and thinks Sandy was a sign of global warming is now telling you all you need to know. JB goes on to say that what he is emphasizing to his clients, is that no matter how much it looks like a ridge may want to show up in the southeast, with ridging over Alaska and negative WPO, the cold will win  So while the current end of November is impressive for the cold and the major storm around Thanksgiving, what is coming down the road may be even more impressive in terms of cold.. and if its as cold as it looks, the snow and ice will take care of itself for many

[uncle W]

I mentioned 1971 the other day...JB's stealing my analogs... ...NYC got 1.35" of precipitation and a trace of snow...Temperature the morning of the event was 26...By the time the precip started temps were above freezing...Albany N.Y. recieved 22.5"...

Albany N.Y. probably won't get anywhere near the snowfall it got in 1971...1971 analog is a wash out...11/28/93 could be a good analog for this storm...this year it will get colder behind the storm than in 1993...

[ChescoWx]

Albany N.Y. probably won't get anywhere near the snowfall it got in 1971...1971 analog is a wash out...11/28/93 could be a good analog for this storm...this year it will get colder behind the storm than in 1993...

Should be a very interesting storm - thanks Unc !

[ChescoWx]

JB paraphrased musings from today where he told his clients this morning that an extreme cold pattern centered over the central US will evolve out of this, and a major fight may be set up between the southeast ridge that will try to show up and the fact relative to size and intensity, the coldest air in the world will be over North America the next 2-3 weeks. He spoke a bit about he WPO/EPO couplet as ruling the roost over the AO and NAO, He mentions he sees the western trough as exploding east in week two as the negative EPO/WPO does not favor a West based trough in winter. He has been bringing up 1983 as an example that was cold all over the states with a vast positively tilted trough.

[NJ_Ken]

JB paraphrased musings from today where he told his clients this morning that an extreme cold pattern centered over the central US will evolve out of this, and a major fight may be set up between the southeast ridge that will try to show up and the fact relative to size and intensity, the coldest air in the world will be over North America the next 2-3 weeks. He spoke a bit about he WPO/EPO couplet as ruling the roost over the AO and NAO, He mentions he sees the western trough as exploding east in week two as the negative EPO/WPO does not favor a West based trough in winter. He has been bringing up 1983 as an example that was cold all over the states with a vast positively tilted trough.

 

I assume by '83, JB is referring to the winter of 83-84.  I just went back to refresh my own memory about that winter, and it was, indeed, pretty darn cold.  Arguably, it was one of the last truly frigid winters we've had in the Mid-Atlantic coastal plain (there have been a few others... 93-94 and 03-04 come to mind... but winters with extended periods of truly frigid cold seem to have stopped being a regular thing around here after the mid-80s).  I only looked at PHL numbers, but, between December 20, 1983 and February 10, 1984, there were a total of 22 days where highs did not break 32 F.  In that same span, there were a total of 26 days with lows in the teens F or below including 8 days in the single digits F and 3 days below 0 F!  That stretch included a couple of historically cold days:  Christmas Day 1983 had a high/low of 10 F/1 F, and January 20 to 22, 1984 featured low temperatures of -3 F, -3 F and -7 F (I am pretty sure that -7 F is the coldest temp at PHL in my lifetime... and I am pretty darn old)!  Ironically enough, for all that intense cold, PHL did not get all that much snow that winter.  Really, there were only two storms of note (a 6-incher in mid-January and 7-incher in early March that is more famous as the storm the old Baltimore Colts used as cover to sneak out of Baltimore for Indianapolis).  Aside from those two events, we had the usual array of flizzards and snow-to-rain events that got us up to 21.1", which is right at PHL's average. 

[ravensrule]

I assume by '83, JB is referring to the winter of 83-84.  I just went back to refresh my own memory about that winter, and it was, indeed, pretty darn cold.  Arguably, it was one of the last truly frigid winters we've had in the Mid-Atlantic coastal plain (there have been a few others... 93-94 and 03-04 come to mind... but winters with extended periods of truly frigid cold seem to have stopped being a regular thing around here after the mid-80s).  I only looked at PHL numbers, but, between December 20, 1983 and February 10, 1984, there were a total of 22 days where highs did not break 32 F.  In that same span, there were a total of 26 days with lows in the teens F or below including 8 days in the single digits F and 3 days below 0 F!  That stretch included a couple of historically cold days:  Christmas Day 1983 had a high/low of 10 F/1 F, and January 20 to 22, 1984 featured low temperatures of -3 F, -3 F and -7 F (I am pretty sure that -7 F is the coldest temp at PHL in my lifetime... and I am pretty darn old)!  Ironically enough, for all that intense cold, PHL did not get all that much snow that winter.  Really, there were only two storms of note (a 6-incher in mid-January and 7-incher in early March that is more famous as the storm the old Baltimore Colts used as cover to sneak out of Baltimore for Indianapolis).  Aside from those two events, we had the usual array of flizzards and snow-to-rain events that got us up to 21.1", which is right at PHL's average. 

Which left me in massive depression for 12 years, at least we got a better team than the loser one that left.

[ChescoWx]

From JBs evening post he has a big worry in days 6-10 in the east that it's not nearly as warm as the old GFS paints it. He says as it usually does it loses the system out in front coming through the ridge and thinks we could wind up with a storm near the east coast Tuesday and Wednesday with northeast winds - He says the ECWMF is all over this as it normally is when the flow is splitting.

[uncle W]

1983-84 was forecasted to be a rough one by some...If it wasn't for the mild february it would have been great...NYC got near average snowfall...NYC got 1" of snow Christmas eve after a deluge of rain a few days before...The first white Christmas since 1980...January was cold with two significant snows...March was very cold and had a 7" storm on the 8th and 3" slush storm on the 29th...

[ChescoWx]

Tweet this AM from Steve D at NYNJPA weather
"A major pattern change is on the way that will eventually lead to a very cold and stormy weather pattern after the first week of December"

[HM]

1982-83/1983-84 are never a good idea to use for analogs for the same reasons 1991-92 through 1993-94 are bad...they are volcanic winters. Now, I'm not saying that we can share similar patterns or behave like these years for a time; but, most peer-reviewed research will reject these winters in their analysis. So, if you are only using 1983, you are likely making a major mistake or your thinking will ultimately lead to error down-the-road, should you get lucky.  

 

1983 is simply hype. Having said that, there is no denying the cold coming into America. But there are many other years to choose from that are more respectable.

[NJ_Ken]

1982-83/1983-84 are never a good idea to use for analogs for the same reasons 1991-92 through 1993-94 are bad...they are volcanic winters. Now, I'm not saying that we can share similar patterns or behave like these years for a time; but, most peer-reviewed research will reject these winters in their analysis. So, if you are only using 1983, you are likely making a major mistake or your thinking will ultimately lead to error down-the-road, should you get lucky.  

 

1983 is simply hype. Having said that, there is no denying the cold coming into America. But there are many other years to choose from that are more respectable.

 

Thanks for the info, HM.  Somewhere deep in the bowels of brain, I am pretty sure I had an inkling of that, but my conscious mind sure wasn't remembering.  

 

It is kind of ironic... well, no, actually, it isn't ironic at all... that the last three times (I think) that PHL reported lows below 0 F ( Jan 1984, Jan 85 and Jan 94) were almost certainly the partial result of volcanic eruptions.        

[RedSky]

Heard there are an unprecedented six volcanoes erupting maybe combined they can help our winter  

[famartin]

Heard there are an unprecedented six volcanoes erupting maybe combined they can help our winter

Too late, main effects won't be til the following winter...maybe later

[HM]

Thanks for the info, HM.  Somewhere deep in the bowels of brain, I am pretty sure I had an inkling of that, but my conscious mind sure wasn't remembering.  

 

It is kind of ironic... well, no, actually, it isn't ironic at all... that the last three times (I think) that PHL reported lows below 0 F ( Jan 1984, Jan 85 and Jan 94) were almost certainly the partial result of volcanic eruptions.        

 

These volcanic winters, in recent-times, coincided with El Niño. There is no evidence they caused the El Niño but no one is saying one way or another here, either. Equatorial stratovolcanoes produce a general strong PV/+AO winter in the first year; however, there is evidence the NAM state gets more disturbed in the following winters with a general winter cooling.

 

The sulfur dioxide is a known ozone destroyer, which weakens the Brewer-Dobson Circulation and strengthens the polar vortex.

 

Remember that this is only for equatorial volcanoes whose eruptions reach the stratosphere.

[HM]

Heard there are an unprecedented six volcanoes erupting maybe combined they can help our winter

 

I heard about the eruptions. Any word on if they reached the stratosphere?

 

Unfortunately, it would only help keep the AO more positive this winter.

[mcwx]

I heard about the eruptions. Any word on if they reached the stratosphere?

 

Unfortunately, it would only help keep the AO more positive this winter.

Mount Sinabung in Sumatra has sent ash to 2000 m the last I read

[HM]

Mount Sinabung in Sumatra has sent ash to 2000 m the last I read

 

Oh okay, that's nothing. Typically over the Tropics, the coldest layer is between 12-18km. For reference, El Chichon reached 20-25km and I think Pinatubo reached up to 30km!

[RedSky]

Mount Sinabung is the largest. There is another in Indonesia, one in mexico the others are minor small eruptions. Don't believe any are on a scale large enough to reach the stratosphere

[mcwx]

Sakurajima (Kyushu, Japan): After a short phase of weaker activity, the volcano began to erupt more violently yesterday with a series of powerful explosions that sent ash plumes up to 15,000 ft (4,5 km). Near-constant ash emissions have been taking place from the Showa crater.

Sinabung (Sumatra, Indonesia): The activity of the volcano continues to increase. More vulcanian-type explosions have occurred over the past days. Since yesterday evening alone, at least 8 explosions have been registered, the biggest one being probably one this morning that produced an ash plume rising to 25,000 ft (7.5 km) and drifting 60 nautical miles to the NW.

These are the two that seem to be ejecting ash into the atmosphere. 

A new island was created off of Japan this week from eruptions. 

[ChescoWx]

Steve D at NYNJPA weather paraphrased from his premium discussions this morning -
He sees the potential is growing high for this winter pattern to really get very snowy and cold for the northern Mid Atlantic.  Development of convection around the date line and the trend towards a weak, west-based El Nino for this winter (unofficially of course) is a huge warning sign for anyone expecting a warm winter.  He is most concerned of the potential of that upper level low over the Southwestern United States.  Based on his research of similar Pacific patterns, he sees the upper level low is likely to retrograde off the California coast as the ridge over Alaska and western Canada builds.  As a result, Arctic air constantly streams in via a cross polar flow and disturbance after disturbances runs in from the Tropical Pacific cutting across the southern Plain with a resulting track towards the Gulf of Mexico and then up the East coast. He summarizes that all the ingredients are now here to make this winter a very stormy and cold winter for the Eastern United States, especially from the Northern Mid Atlantic on south to the Gulf Coast.

[ChescoWx]

Some JB musings from his post this midday

He talked a bit about his dismay with both US  and ECWMF models, which got killed in November and had the entire nation warm in December. However it appears the JMA has been catching what is going on more and the Korean, as he showed this week also had a temp representation that looked more like what we see modeling going to. But there are contradictions here that Joe D and JB are focusing on and trying to point out. The WPO and EPO to both of them, has been winning the temp representation battle overall, as the warmups that have come ( and one is going on now) have been met with cold even stronger and longer behind them. JB sees a period for a while before what I think is going to be a cold January, that warm can try to beat cold, but given the amount of cold in Canada, all it takes is slight buckling and the cold later in the December comes again, in what might look like a warm pattern.

He goes on to talk about all the happy talking about it getting so warm would need to be trimmed and indeed it has.  Its milder east ( but near normal for Dec 1). He thinks the cold coming into the west and plains will be, for this time of the year "punishing". with teens in Dallas,....above normal snow and ice is going to occur from the southern plains to the mid and north atlantic states ( for this time of the year) He mentioned that we see the ECMWF seeing the pressing cold and what may be a "phantom" storm for the 8th

[ChescoWx]

JB paraphrasing from today 
 Talks of this being the nations coldest November since 1996, largely unforecasted, and a cold outbreak to start the month that resembles 2009 (which did not have the cold November) the battle turns to how mild it might get after?. Look at this current warm up we are in the midst of now - In 5 days it will be gone, replaced by 10 days of cold, 5 of them extreme, in the nation's breadbasket. So he sees the threat of another warm up in week 3 but once again it will be beaten back and reversed as cold continues to outduel warm as it has all fall and now into met winter. He says perhaps this time the warm will out duel the cold ) but the post Arctic shot period may be a case of warmth that comes and goes again. This is what to keep in the back of your mind with model waffling and pronouncements of warm ups, even as the details of cold in front of us have not yet been seen for what they are. He highlights that there were close to 1,000 low temperature records the last week of November.

He says that once into weeks 3 and 4, we should look at the ensemble means. That means of a lot of options, one of them being something like this, everyone jumps into the warmer boat, and then yet another "surprise" cold shot shows up in areas. He takes a shot at the GFS runs and the reactions all will have to deal with there..

[ChescoWx]

Per Steve D. NYNJPA Weather on his 4pm public tweet and article today

"Threat for Winter Storm Growing for Next Week"

"My theory is this cold air is going to be stronger than what is currently modeled and we have a sense of the models catching up to this potential as the surface high pressure systems associated with this air mass are showing up stronger with each passing day.  This is a major concern because the more stubborn the cold air is to be routed out, if it ever is, the higher the threat will be for ice accumulation in the form of sleet and freezing rain.  This threat at this time is primarily for locations in higher elevations like in interior eastern Pennsylvania, northwestern New Jersey, the Hudson Valley, and northwestern Connecticut"  "My point here today is to tell you, yes there is a winter storm threat brewing for next week and you will likely hear a lot about this threat with model snow maps and the like.  However, there are a lot of details to consider before snow map considerations and other aspects.  I suspect the models won’t catch on to the strength of the Arctic air until that air mass is knocking on the door step of Texas by mid week.  Further, I have little trust in any model handling the disturbances embedded in this Sub Tropical jet stream thanks to the lack of sampling and the known errors of even the best models in these types of cases"

[ChescoWx]

From NYNJPA weather Steve D this AM

An advancing warm front will produce periods of snow on Sunday night changing over to sleet and freezing rain by Monday morning and finally rain by Monday afternoon.  Snow and ice accumulations are expected before a change over to rain.  Temperatures will range from the mid to upper 20′s for lows and the upper 30′s to mid 40′s for highs.

[ChescoWx]

From Steve D at NYNJPA Weather this AM  - He is very bullish on accumulating snow for Saturday AM before the next Sunday night event
The overall theme here is that the Arctic cold front will drop south through the Philadelphia and New York City metropolitan areas on Friday night into Saturday morning.  Cold air will drive towards the coast leading to temperatures falling below freezing over the interior and close to freezing along the coast by Saturday morning.  Meanwhile, a strong disturbance at 500 MB to 700 MB combined with a tight thermal gradient will support a period of light to moderate snow as the Arctic cold front exits.

 

The threat for accumulating snowfall is highest over eastern Pennsylvania, especially as you head towards central Pennsylvania where as much as six inches of snow will be possible.  Time of the cold air at the surface to support accumulation will be the primary wild card.  Overall I'm expecting much of eastern interior Pennsylvania (generally 10 to 15 miles west of the Delaware River) to support snowfall totals of 2 to 5 inches with the majority on cold surfaces and the grass.  Further to the east, snowfall accumulation will be limited to cold, grassy surfaces and less likely on the roadways.  Snowfall accumulations just northwest of the major cities will range from one to three inches and a trace to an inch in the urban areas and along the coast.

 

After this Arctic cold front moves through, then we turn our attention to Sunday night into Monday which I will discuss in the Long Range Thoughts.

[RedSky]

ECM has been indicating a small accumulation of snow in PA N&W of Philly before precipitation ends on saturday morning up to 1"