Vendor Forecast Discussion

[ChescoWx]

Dr Joe D from WB paraphrasing from his AM blog today

He is looking at a west QBO near the solar max and with a negative SOI developing  likely means a colder than normal January and February east and southeast. He notes the negative correlation with positive solar flux and temperatures. A negative as in much of the central and east including the southeast means cold January and February. Note the hint of a block in eastern Canada.

[Blizzard-on-GFS]

 

[ChescoWx]

 

Just a note - this is obviously not a vendor forecast so should not be here - thanks!

[ChescoWx]

Steve D's Final Forecast for Sunday/Monday
PHL and nearby burbs 1-3" snow followed by 0.5 to 0.10" ice
Far N and W burbs (far NW Chesco and out) 2-4" snow followed by 0.15 to 0.25" ice
My Wxsim forecast is a bit more conservative and has 1-2" of snow followed by 0.10" ice

[ChescoWx]

From JB on Weatherbell today on tomorrow's next winter event
Spoke about what he calls "magic" chart. The Magic chart was taking total 700mb upward motion over a 6 hour period and finding the intersection with the -8C line at 5k. Forecasters developed a formula ( when its -8C at 5 k, the depth of the cold is such that it encourages faster crystal growth) that would take precip amounts and sometimes turn them into 3 times the amount of snow forecasted at the 10 to 1. Also mentioned to watch the 528 thickness, with the movement of the -8C line at 5 k to see if any lollipop fluff snow is going to occur. He said his test will be if a place like Hazelton gets as much as PHL.. Hazelton should go to 20 to 1, PHL should stay close to 10-1. Both places should have a 3-6 locally 8 snow

[Blizzard-on-GFS]

[nynjpaweather]

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"

 Yep, and it certainly has been so far.

[ChescoWx]

 Yep, and it certainly has been so far.

Excellent call Steve

keep up the great work!

[ChescoWx]

Paraphrasing From JB this PM on Weatherbell on the next winter event in our future

He is confident about this storm over the weekend (calls this the first storm - as a 2nd is in line next week) being mainly snow north of the Ohio river and Mason Dixon line, with a fight in the coastal plain, is that snow breeds cold and snow breeds snow. He says snowcover makes the air over it colder, which affects the pressure, which expands the dome of cold and also supplies a boundary where cold resists warm. Storms travel further south for one and the dome of cold, if only slightly larger, is big enough so when lifted, cools the air and makes what might have been rain or sleet snow. He sees the trend of the models to be predictable give the cold around, bottom line he likes the ECWMF on number 1 this coming weekend.

[Ralph Wiggum]

Local news timid to take a stab at weekend system going with snow and/or wintry mix to rain for now...all bases covered.

[ChescoWx]

Latest forecast map from Steve at NYNJPA weather via a tweet this AM

[ChescoWx]

Latest JB tweet has him stating that Cold air is indeed likely to hold firm north of the mason dixon line - as he said it just wants to snow in PHL this year!!

[ChescoWx]

JB's latest tweet after 12z runs

"NW Burbs PHL to NYC likely all snow - Cities and southeast change for a time - he likes 3 to 6" for center city Philly and CPK in NYC"

[ChescoWx]

Latest "banding" ideas from Steve at NYNJPA weather

[ChescoWx]

This mornings forecast from Steve at NYNJPA weather

[ChescoWx]

Interesting write up from Steve D from NYNJPA Weather  on what looks to be a very brief warm up and then back to the cold....

 

"Studying all the models beyond seven days, we are heading back into the freezer and with a very active Sub Tropical jet stream to boot.

Let me be clear that once again, the details on the models are not to be trusted.  I can already see many posting the CMC guidance for 192 to 240 hours showing a powerful winter storm the the northern Mid Atlantic.  Stating that, let me be clear that there are clear signs of not only a more powerful negative EPO/WPO pattern than we saw for much of December but now clear signals of a weak negative Arctic Oscillation and North Atlantic Oscillation that will lock in for the first week of January.

 

The key to the shift in the Atlantic will start to evolve with what looks to be a powerful winter storm over northwestern Europe that will force the above normal heights around Scandinavia to shift towards Greenland and towards the North Pole.  This in turn finally kick starts the process of forcing the Polar Vortex over North America further south and produces below normal heights over much of the northern Atlantic.

 

Let me be clear that this pattern is not an a typical negative AO/NAO pattern.  This is a pattern that is driven by the building above normal heights that link up from the western Pacific through Alaska into northeastern Europe, basically driving below normal heights into the eastern two-thirds of the United States and over western Europe.  The result of this pattern when combined with the Sub Tropical jet stream undercutting the ridge over the western Pacific will lead to another round of dynamic contracts between the Tropical air from the Sub Tropical jet stream and the Arctic air masses driven by the Polar and Arctic jet streams.  Note with the Polar jet stream, a clear northwesterly flow will be established from Siberia right into the eastern two-thirds of North America and specifically towards the East coast.

 

The blocking over the Northern Atlantic will likely lead to a better potential for disturbances to interact along the East coast, but we still won't feature an optimal block in this set up.  Expect more of the wintery mix type storms that can be very difficult to forecast for and typically feature isentropic lifting events, called overrunning on media outlets.  Look for a storm track with Arctic cold fronts diving south with clipper like influences followed by Sub Tropical disturbances that will ride along the Arctic boundary.  Depending on interactions with Polar disturbances, these storms can lead to significant winter storms.  One word of caution, the models will likely continue to underestimate the strength of Arctic high pressure systems and Arctic air masses in general."

 

[ChescoWx]

Paraphrasing From WeatherBell and JB today...
Talks about how the last hot shot ended with snow in the mid and north atlantic states and that it may in fact do so again. He sees the GFS hinting and the Canadian moreso, that a "sneaky wave" develops on Christmas eve day and delivers snow where it wants to snow this year - right in our backyards. He is not forecasting this but thinks it has a shot. As it fits with what the pattern has been a small island of warmth in a broad sea of cold.

[dankil13]

 

Interesting write up from Steve D from NYNJPA Weather  on what looks to be a very brief warm up and then back to the cold....

 

"Studying all the models beyond seven days, we are heading back into the freezer and with a very active Sub Tropical jet stream to boot.

Let me be clear that once again, the details on the models are not to be trusted.  I can already see many posting the CMC guidance for 192 to 240 hours showing a powerful winter storm the the northern Mid Atlantic.  Stating that, let me be clear that there are clear signs of not only a more powerful negative EPO/WPO pattern than we saw for much of December but now clear signals of a weak negative Arctic Oscillation and North Atlantic Oscillation that will lock in for the first week of January.

 

The key to the shift in the Atlantic will start to evolve with what looks to be a powerful winter storm over northwestern Europe that will force the above normal heights around Scandinavia to shift towards Greenland and towards the North Pole.  This in turn finally kick starts the process of forcing the Polar Vortex over North America further south and produces below normal heights over much of the northern Atlantic.

 

Let me be clear that this pattern is not an a typical negative AO/NAO pattern.  This is a pattern that is driven by the building above normal heights that link up from the western Pacific through Alaska into northeastern Europe, basically driving below normal heights into the eastern two-thirds of the United States and over western Europe.  The result of this pattern when combined with the Sub Tropical jet stream undercutting the ridge over the western Pacific will lead to another round of dynamic contracts between the Tropical air from the Sub Tropical jet stream and the Arctic air masses driven by the Polar and Arctic jet streams.  Note with the Polar jet stream, a clear northwesterly flow will be established from Siberia right into the eastern two-thirds of North America and specifically towards the East coast.

 

The blocking over the Northern Atlantic will likely lead to a better potential for disturbances to interact along the East coast, but we still won't feature an optimal block in this set up.  Expect more of the wintery mix type storms that can be very difficult to forecast for and typically feature isentropic lifting events, called overrunning on media outlets.  Look for a storm track with Arctic cold fronts diving south with clipper like influences followed by Sub Tropical disturbances that will ride along the Arctic boundary.  Depending on interactions with Polar disturbances, these storms can lead to significant winter storms.  One word of caution, the models will likely continue to underestimate the strength of Arctic high pressure systems and Arctic air masses in general."

 

 

New drinking game... do a shot every time you see the word "clear" in this write-up!  

[ChescoWx]

JB begin to call on the ghosts of that most memorable winter in this area - 1993/94 as he looks at what is shaping up to be a very interesting January

[Snow Man]

That was agreat winter. Tremendous cold followed by a significant snow/ice storm every four days. By the end of the winter my street was like a glacier and my christmas lights were frozen under amountain of snow and ice. I couldn't take them down until April.

[ChescoWx]

Hi Carmen

 

Agreed...probably the most memorable and severe winter in my lifetime (not the snowiest) but for a combination of sustained cold/incredible amount of ice and snow if was the most impactful. I remember driving on Rt 202 in Chester County and trying to avoid the huge blocks of ice that were just littering the highway...and this was 3 days after one of the multiple snow/ice events of that winter season. That was also the winter with the only day in the record books for Chesco that there was a day that the temp never rose past zero during an entire day. I saw today that Steve at NYNJPA is also mentioning that this has a similar look to it to 93/94. No 2 years are ever really the same but it should be a very interesting stretch of winter weather for those who like it cold

[White_Mtn_Wx]

93/94 was historic. I provided field reports to channel 3 OCM David Rogers at the time. Memories....Witnessed 12f and driving rain. I'll never forget walking out to the station provided thermometer to take that ob! Ice on the Cville Reservoir was literally 2' thick. Stuck my hockey stick in an ice fishermans hole and it went halfway down before the blade curled horizontally on the bottom of the ice. It was fascinating to cut a cross section of the backyard glacier in late March, it was like a seeing tree rings, you could revisit each storm that laid its layer. There are so many more to recall. Thanks to Paul and Carmen for inspiring the memories.

[mookiemike]

93/94 was historic. I provided field reports to channel 3 OCM David Rogers at the time. Memories....Witnessed 12f and driving rain. I'll never forget walking out to the station provided thermometer to take that ob! Ice on the Cville Reservoir was literally 2' thick. Stuck my hockey stick in an ice fishermans hole and it went halfway down before the blade curled horizontally on the bottom of the ice. It was fascinating to cut a cross section of the backyard glacier in late March, it was like a seeing tree rings, you could revisit each storm that laid its layer. There are so many more to recall. Thanks to Paul and Carmen for inspiring the memories.

Wasn't that the season of the February 1994 event about three days after an ice storm put down two plus inches of pure ice on Philadelphia? I remember early WSW went up, but still dutifully prepared for school, only to get trapped coming home, deciding to go on foot. There was awesome thundersnow, and though only a mile and a half to home, I almost didn't make it. I realized my weather mortality from that snowfall.

[famartin]

The biggest Philly ice event was Friday January 7th, 1994.  Ice accretions in central NJ and SE PA were 1" in places.  There was another big ice event on Monday January 17th but it wasn't as bad and was mainly northwest of I-95.  This second event was followed by widespread sub-zero readings by Wednesday January 19th.  February featured two heavy snow events, one on Tuesday February 8th which transitioned to sleet and freezing rain (not horrible amounts of ice like in January) and lingered through Wednesday February 9th.  Thursday February 10th was dry but cold and cloudy, then another heavy snow to sleet event enveloped the area on Friday February 11th.

[iceman56]

That January day in 1994 I recorded a max of -1 and a low of -17 here in NW Chesco.

Those subzero reading have been exceedingly rare in recent years even though I'm in a

valley at 352' that radiates very well with snow cover.

[ChescoWx]

That was the day Coatesville recorded the same - it is the only such day in the 120 year dataset. I have only recorded 1 sub zero low here in the 10 years I have lived at this elevation....no doubt a few more at your spot

That January day in 1994 I recorded a max of -1 and a low of -17 here in NW Chesco.

Those subzero reading have been exceedingly rare in recent years even though I'm in a
valley at 352' that radiates very well with snow cover.

[ChescoWx]

From JB at WB this AM to paraphrase

This December will now be the coldest in the US since 2000 for the nation as a whole, He mentions that the rest of the market is giving up on a warm January, which the folks at WB think has alot of similarity to 1994. He stresses that he is not saying it will be as impressive of a snow/ice pattern we had that year, but with the means so close its likely that many lovers of winter weather will find that the best is yet to come in the Plains and the East. He even says it will attack the southeast heat fortress. He closes with the statement what we may wind up with Nationally the coldest October-Jan period since 1976-1977 - now that is impressive!

[KamuSnow]

The biggest Philly ice event was Friday January 7th, 1994.  Ice accretions in central NJ and SE PA were 1" in places.  There was another big ice event on Monday January 17th but it wasn't as bad and was mainly northwest of I-95.  This second event was followed by widespread sub-zero readings by Wednesday January 19th.  February featured two heavy snow events, one on Tuesday February 8th which transitioned to sleet and freezing rain (not horrible amounts of ice like in January) and lingered through Wednesday February 9th.  Thursday February 10th was dry but cold and cloudy, then another heavy snow to sleet event enveloped the area on Friday February 11th.

There had been some freezing rain between 6 and 9 am that Friday but it warmed up a few degrees during the day. I went out and bought a generator in anticipation of what was forecast for that night. And it was impressive. Outside around 11 pm you could hear the regular sound of branches breaking and transformers blowing up in the distance with the accompanying green glow. There were icicles hanging from everything for a few days. Later that winter we were sledding  on 3" of ice on about a 5 degree incline (before we go to the steep part of the yard!). It looked like the ice had been poured over the landscape. That winter was dubbed "the ice winter".

[ChescoWx]

More from JB today on the growing discussion of 1994 similarities

 

"So its starting. Is it exactly the same? No,but its very similar and its telling you that what is on the table is, as we are saying the threat of the coldest Jan for the US as a whole since 1994. Is it going to hit 20 below in chicago, teens in Houston snow 2 feet in NYC and ice up DC a couple of times. I cant say that, but I can say that what will likely be the coldest US December since 2000 should be followed by a big cold month in January"

[tcutter]

There had been some freezing rain between 6 and 9 am that Friday but it warmed up a few degrees during the day. I went out and bought a generator in anticipation of what was forecast for that night. And it was impressive. Outside around 11 pm you could hear the regular sound of branches breaking and transformers blowing up in the distance with the accompanying green glow. There were icicles hanging from everything for a few days. Later that winter we were sledding on 3" of ice on about a 5 degree incline (before we go to the steep part of the yard!). It looked like the ice had been poured over the landscape. That winter was dubbed "the ice winter".

It was almost like the day after tomorrow, everything froze so quickly and in the honey brook area there were ice potholes, it was crazy and even the highways were icy for a few weeks