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Rainshadow

Meteorological Winter Pattern Discussion

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00z Jan 2nd GEFS

Above normal 500mb heights through January 9th (whoops a really awful and not even entirely within week 2 bust) except for passing to the north trof on the 3rd and weakening neg tilt trof afternoon of the 5th.  On January 9th the Pacific remains hostile (+EPO), but +PNA amplification & -NAO retrogression briefly bring bring near normal heights on the 9th & 10th. From the 10th through the 17th heights vary from above to near normal predicated on flexing of the PNA ridge and a developing less hostile EPO pattern (some ridging vs troffing thru Alaska).   This idea seems similar to GEFS from two days ago, but still in week 2 land for the most part.  For now fwiw it looks like a colder air dump west of our area. 

NAEFS 1/10-1/17 has some confidence of above normal weather in our area.  First time since pre Christmas that it has hinted at this. 

 

00z Jan 5th GEFS

Below normal 500mb heights this weekend from departing system and trof diving into New England.  A repeat from a Canadian trof that gets slowed by the -NAO on the 9th & 10th. (Above normal heights between trofs).   Above normal 500mb heights on the 11th & 12th before PNA ridging becomes stronger and next weekend trof moves off the east coast.  On Monday the 14th there is an Aleutian low, the NAO is trending more positive and the EPO while positive looks less hostile.  This leads to above normal heights west and northwest in NOAM and near normal heights here thru the 17th.  To the end of the run on the 20th heights are either below or near normal with the PV sinking toward Hudson's Bay, a +PNA pattern continuing and a -NAO pattern emerging.  I probably would say the EPO remains positive.

NAEFS 1/13-1/20 has alot of uncertainty on the map about temperatures.  We are barely within near normal confidence here. 1/11-1/18 was the first time since pre mid November that our entire area had confidence of above normal temps and with the MJO shooting out of a cannon again, unless a system cuts again that will be tough to average above. 

 

00z Jan 7th GEFS

Above normal 500mb heights through the 8th.  A Canadian trof that gets slowed by the -NAO with below normal heights on the 9th thru 11th. Above normal 500mb heights return on the weekend preceding the southern stream system.  Then what looks like to be the last period of above normal 500mb heights quickly returns thru the 17th.  On the 17th  an Aleutian low is in place, +PNA, weakly -NAO and upper Hudson Bay TPV.   This starts us with near normal 500mb heights which become negative on the 20th and lasts thru end of run on the 22nd.  The EPO still looks positive, but the amplitude of the PNA and weak -NAO more than compensates.

NAEFS 1/15-1/22 keep us in near normal temperature confidence.  I suspect first half of period is warm, second half cold.  GEPS amplitude is less than GEFS.  EPS looks slower than the GEFS and I will side with it because I have been chirping about January 22nd being the SSW day and will vehemently agree with any piece of guidance that corroborates this. 😛😮😉  

 

00z Jan 9th GEFS

Below normal 500mb heights from our Canadian trof slowed by the -NAO lasts into the 11th. Above normal 500mb heights return on the weekend preceding the southern stream system. Our heights average near normal through the work week as a strong western NOAM ridge negates the +EPO flow from a neg tilt eastern Pacific system.  Above normal heights for this week have just about disappeared. On the 17th (the end of modeling skill with teleconnections) we have a upper Hudson Bay PV / +EPO / +PNA / +NAO pattern with our 500mb flow from southern British Columbia.  Over the weekend the NAO trends more negative with the Pacific trof/closed low retrograding. Below normal heights still begin on the 20th (same date as two days ago). Through the end of its run on the 24th, the Hudson Bay PV sinks farther south and the -NAO becomes stronger (Pacific unchanged) with below normal 500mb heights continuing. 

NAEFS 1/17-1/24 keep us in higher confidence of near normal temperatures.  This is on the GEPS which is warmer during the first half of the period than the always colder GEFS.  The EPS is siding with the GEPS with less dollar cost averaging amplitude of systems and keeping the Hudson Bay PV kind of on an island.  So the perspective week 2 biases of each model remain where they have been.   

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1 hour ago, Mitchnick said:

So am I the only one who thought last night's EPS run were not that great. Warm period in there before cooling at the end.

you were the only one. They got colder from 12z run

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1 hour ago, Mitchnick said:

So am I the only one who thought last night's EPS run were not that great. Warm period in there before cooling at the end.

you were the only one. They got colder from 12z run

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It's been a long haul, but our sort of Nino climo wins out.  Ridge builds into Alaska and AO region, allowing PV to slide south.  PV should keep a cold NW flow close by for any storms that ride the souther stream.  STJ active.

gfs_uv250_namer_fh126-198.gif.093fccbe30b8d360f10a5a1613dc5b74.gif

You can see the potential 1/20 storm getting its act together as PNA builds  

gfs_DTpres_nhem_fh156-204.gif.9b530d7828963d3556ede7e2f5412991.gif

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gfs still not bringing really an strong strat effects down. Curious to see why cfs and euro weeklies are so cold unless they think those work downward. Looks like phase 5 by of mjo close to start of feb

geos_nh-u60_20190110.png

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38 minutes ago, tombo82685 said:

gfs still not bringing really an strong strat effects down. Curious to see why cfs and euro weeklies are so cold unless they think those work downward. Looks like phase 5 by of mjo close to start of feb

geos_nh-u60_20190110.png

Wow, basically a warm start to February if it were to hold up? Winter in this area will make you go crazy,ha

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1 hour ago, phillysports11 said:

Wow, basically a warm start to February if it were to hold up? Winter in this area will make you go crazy,ha

No, mjo isn't everything and plus it looks to weakly go into 4/5 right now. You still have just canonical nino forcing in feb and I would assume cfs and euro weeklies have strat effects. Thats what I'm wondering at least

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Jesus... who ran the 18z GFS?! Weenie heaven. 

 

But going forward, the pac is starting to slow down. The Aluetian low will be able to pump up PNA ridges, and as well as the EPO domain. The Atlantic will be neutral- favorable to highly favorable at times. (Part tropospheric influences, part SSW/SPLIT affects). 

We’re just getting started. We’re about to Jekyl and hide this winter...

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Best of the EPS this season. Multiple snow threats and brutal cold look at the end. 

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Going forward, we’re starting to see the strat effects! TPV will be a constant around Hudson Bay, making sporadic visits with any amplified systems dragging it further south. Great cold source region! 

Very active split flow pac jet! That’s a favorable pac set up with systems undercutting the PV. We’re already seeing that on modeling. Doubt we see any “torch” spikes in the next 3-4 weeks. And if any, would be limited. 

 

Winter is here, let’s hope we can all cash in!!

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00z Jan 5th GEFS

Below normal 500mb heights this weekend from departing system and trof diving into New England.  A repeat from a Canadian trof that gets slowed by the -NAO on the 9th & 10th. (Above normal heights between trofs).   Above normal 500mb heights on the 11th & 12th before PNA ridging becomes stronger and next weekend trof moves off the east coast.  On Monday the 14th there is an Aleutian low, the NAO is trending more positive and the EPO while positive looks less hostile.  This leads to above normal heights west and northwest in NOAM and near normal heights here thru the 17th.  To the end of the run on the 20th heights are either below or near normal with the PV sinking toward Hudson's Bay, a +PNA pattern continuing and a -NAO pattern emerging.  I probably would say the EPO remains positive.

NAEFS 1/13-1/20 has alot of uncertainty on the map about temperatures.  We are barely within near normal confidence here. 1/11-1/18 was the first time since pre mid November that our entire area had confidence of above normal temps and with the MJO shooting out of a cannon again, unless a system cuts again that will be tough to average above. 

 

00z Jan 7th GEFS

Above normal 500mb heights through the 8th.  A Canadian trof that gets slowed by the -NAO with below normal heights on the 9th thru 11th. Above normal 500mb heights return on the weekend preceding the southern stream system.  Then what looks like to be the last period of above normal 500mb heights quickly returns thru the 17th.  On the 17th  an Aleutian low is in place, +PNA, weakly -NAO and upper Hudson Bay TPV.   This starts us with near normal 500mb heights which become negative on the 20th and lasts thru end of run on the 22nd.  The EPO still looks positive, but the amplitude of the PNA and weak -NAO more than compensates.

NAEFS 1/15-1/22 keep us in near normal temperature confidence.  I suspect first half of period is warm, second half cold.  GEPS amplitude is less than GEFS.  EPS looks slower than the GEFS and I will side with it because I have been chirping about January 22nd being the SSW day and will vehemently agree with any piece of guidance that corroborates this. 😛😮😉  

 

00z Jan 9th GEFS

Below normal 500mb heights from our Canadian trof slowed by the -NAO lasts into the 11th. Above normal 500mb heights return on the weekend preceding the southern stream system. Our heights average near normal through the work week as a strong western NOAM ridge negates the +EPO flow from a neg tilt eastern Pacific system.  Above normal heights for this week have just about disappeared. On the 17th (the end of modeling skill with teleconnections) we have a upper Hudson Bay PV / +EPO / +PNA / +NAO pattern with our 500mb flow from southern British Columbia.  Over the weekend the NAO trends more negative with the Pacific trof/closed low retrograding. Below normal heights still begin on the 20th (same date as two days ago). Through the end of its run on the 24th, the Hudson Bay PV sinks farther south and the -NAO becomes stronger (Pacific unchanged) with below normal 500mb heights continuing. 

NAEFS 1/17-1/24 keep us in higher confidence of near normal temperatures.  This is on the GEPS which is warmer during the first half of the period than the always colder GEFS.  The EPS is siding with the GEPS with less dollar cost averaging amplitude of systems and keeping the Hudson Bay PV kind of on an island.  So the perspective week 2 biases of each model remain where they have been. 

 

00z Jan 13th GEFS

Above normal 500mb heights (and it still snowed) into the 15th.  Struggle between Hudson Bay Vortex/ -NAO and +EPO as far as our heights go, quite the gradient across eastern NOAM.  Positive heights return before exiting preceding the predicted big system for next weekend.  Neg tilt below normal heights with it on the 20th & 21st.  On the 22nd, we have the Aleutian low, eastern Pacific ridging and -NAO outlooked.  Troffing though is more central NOAM than east from four days ago. Below normal heights can kicked to the 25th (four days later its five days later).  Cold shots are coming, angle of cold as to how brutal here.  Shocker below normal heights with a -NAO/+PNA/Hudson Bay low then continue thru the end of its run on the 28th.  GEPS, EPS similar.

NAEFS for the week of 1/21-1/28 is in I don't know mode as to temperature confidence.   Higher confidence of a cold week are west of us in the Ohio and Mississippi Valleys.

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23 hours ago, tombo82685 said:

GIGI!!!!!!!

 

ecmwf_t2min_nj_37.png

Well I am somehow 1F warmer than PHL (Parsley 7F warmer than PHL, I am jealous), so I have that going for me.

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1 hour ago, tombo82685 said:

 

1 hour ago, tombo82685 said:

GIGI!!!!

903B16EA-70D4-436C-9995-F964CC11F625.png

 

So my name only gets bolded if mins are lower than -5?

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16 minutes ago, Rainshadow said:

So my name only gets bolded if mins are lower than -5?

Lol I was on my phone and I didn’t see option to increase size of text. Anything under 0 is bolder and 72 font size 

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3 hours ago, tombo82685 said:

Lol I was on my phone and I didn’t see option to increase size of text. Anything under 0 is bolder and 72 font size 

At least I am comforted that the OP is a SREF induced outlier.  Ensemble mean for PHL is about 15 degrees warmer which at this point I'd take it.

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One thing that kind of worries me is the lack of ridging out west. I'm not sure if thats in response to an unfavorable mjo or what. That makes the pv location even more important. 

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30 minutes ago, tombo82685 said:

One thing that kind of worries me is the lack of ridging out west. I'm not sure if thats in response to an unfavorable mjo or what. That makes the pv location even more important. 

Maybe it is fast, but the amplitude is increasing (wow, never saw that one coming) and a mode conflict is coming.

diagram_40days_forecast_GEFS_member.gif.333ae7c3a499d5d6a0dfd29afdd27229.gif

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5 minutes ago, Rainshadow said:

Maybe it is fast, but the amplitude is increasing (wow, never saw that one coming) and a mode conflict is coming.

 

yup, but I'm not sure if we get the same response due to where the AAM is at now compared to what it was in dec. Believe dec it was -aam this time I think we have +aam. So we may get a different response. But yea, the mjo is def a mode conflict in terms of what modeling is showing move forward and probably why we can't hold a pna ridge.

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EPS keeps the PV firmly entrenched sending waves of cold and perturbances in the long wave pattern.

image.png.30f865298c8c4799e12f2f5afaaa7bac.png

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