Jump to content

*** PLEASE REGISTER AND JOIN OUR DISCUSSION!!! ***

THE STAFF WANT YOU TO JOIN US AT PHILLYWX!!!

Register as a member today, and become part of the Delaware Valley weather community!

Our pro and seasoned amateur meteorologists, and weather enthusiasts from around the PA and NJ area together form a great group discussion, and we're asking folks that read our site today to register as members and post along with us!

Don't be intimidated if you're not an expert, ask questions if you're curious or want to build your knowledge!

Whether it's adding to our local profiles by reporting observations (and maybe becoming a SkyWarn Spotter!), or contributing more on the model interpretation side, we'd like you to join us in a constructive and insightful dialogue around all things Philly Weather!


tombo82685

Administrator
  • Content Count

    32,881
  • Joined

  • Last visited

  • Days Won

    167

Everything posted by tombo82685

  1. I'd be shocked if anyone gets more than a half inch of snow out of this. This looks more and more like rain over to some festive flakes before ending. Any area that can get a burst of snow could get some minor accum
  2. December looks troubling to me honestly. You already have the canonical nino that generally leans warm for the east. Throw a robust mjo going through torch phases and it may not be good. The unknown variables are nao domain and what happens in the strat which can alter everything
  3. Yea there is going to be some pac flow into western Canada as that Aleutian low moves out a favorable area next week or so. Personally I don't think it's a permanent feature. SST just tell me there wants to be more of ridge out somewhere between alaska and the west coast. I think the bigger issue for December isn't pac flow but more of a -pna esp with where the mjo is headed
  4. So now that we are closing in on mid November, where are headed for the second half of the month? If we look at the current 5 day h5 hgts anomalies from today to Friday. We can see on the map below we have our +pna pushing into the -epo domain then ridge bridge across the top over the pole into Scandinavia. All thise high latitude blocking displaces the cold anomalies that are normally at the pole and relocates it into the mid latitudes. We also have a nice Aleutian low which also teleconnects well to a +pna. All of this basically means there is going to be a nice trough in the east with potentially arctic intrusions with that big -epo, which we have gotten. Here is the next 5 days from nov 15th-20th. We still have our Aleutian low, but it's starting to shift out of the Aleutians and build more towards Siberia and into Alaska. Our PNA ridge has shifted westward off the west coast due to the shuffling of the Aleutian low. The big ridge bridge across the top has broken down and we now have low hgts on the north American side of things but still a big Scand ridge. Without the big poleward -epo and properly placed pna ridge, arctic air into the US should be at a minimum. We should see some Pacific puke start entering the US, specifically the western US/canada into the plains as the ridge out west flattens out a bit in response to the lowering hgts in Alaska. The east will still be under nw flow to start the period but then more zonal to sw flow as the ridge out west retrogrades offshore pulling the trough in the means towards the plains/lakes. Even though there is below normal hgts in the east, the source region is right off the north pacific, so it's not a cold look, nor warm. Next is the 10-15 day period so from nov 20 to nov 25th. We still have our big scand ridge that grows even stronger. This is also starting to push into Greenland for an east base -nao look. We lost the Aleutian low which has moved over Siberia/arctic circle area. The low hgts over this part of the area into Alaska will continue to promote some pacific flow into the US again. The ridge out west continues to be featured off shore mainly which promotes more of a trough into the plains/lakes so not ideal for noreaster developments or snow in this look. In this time period we will have to see how the nao domain starts to materialize as modelling is trying to build something is this timeframe. MJO currently is coming into phase 6 and will be getting into phase 7 by end of this week, then phase 8 and 1 for next week into the start of Thanksgiving. Phase 6 of the MJO favors zonal flow across the US and phase 7 favors cold push into the plains with a se ridge look. This fits well as to what the eps are starting to show for this weekend and beyond. We start with some PAC flow then as the pna ridge retrogrades westward the main trough axis pulls west as we start getting some se ridge looks. Phase 8 favors cold in the northeast, while phase 1 favors a -pna look. Looking at the Wave potential velocity maps, this wave should continue around again through phase 2 and so on. Phase 2 should occur by the end of November which is bias cold in the east but a transition phase. Looking at the strat we are at the peak of our wave 2 hit that helped in bringing multiple Barneys to the area. The wave 2 hits to the strat look to subside over the next week and we start to get a big wave 1 displacement event of the PV. The euro by day 10 is just starting to sniff out the wave 1 look while the GEFS are going full bore on this. this is day 10 on the gefs, you can still see the wave 2 look on the temperature anomalies but the Siberian ridging is starting to take control. By day 15, we have a full on PV displacement off the pole by a significant wave 1 hit as the pv gets displaced to Europe The temperature anomalies are getting close to SSW territory here as there is a robust warm signal over the pole. Right now we have a strong PV but the wave 2 hits we are seeing followed up by a big wave 1 hit weakens the pv zonal winds big time as it's in a free fall. If we were to follow up this big wave 1 hit up with a good wave 2 hit in December it could be enough to shred the PV at some point in Dec. So in conclusion, after the Barney shots of cold this week and then a secondary push this weekend we should moderate to around normal, some days a little below some a little above as we get the influence of PAC flow. As the ridge out west backs up offshore that should pull the trough a bit further west, so while it won't be a torch any stronger system will most likely cut to our west as we get a bit of se ridge in response to where the trough is. I think we may get another shot of colder air just prior to Thanksgiving or right around there in response to where the MJO goes. Strat induced effects to the weather I think will remain quite low and the pattern will be more controlled by the MJO. Any strat impacts I think will be more towards late Thanksgiving and start of December depending on how/if that wave 1 hit develops. One other wild card which may also be influenced by the strat would be in the nao domain. Have to start watching this once we get past Nov 20th as that big scand ridge may try and retrograde a bit into Greenland and also how the strat displacement evolves as well.
  5. euro 11/9 12z: .16 snow .4 11/10 0z: .35 snow .8 11/10 12z: .35 snow .7 11/11 0z: .26 snow .4 11/11 12z: .24 snow .2 11/12 0z: .19 snow .1 eps 11/9 12z: .23 snow .7 11/10 0z: .36 snow .7 11/10 12z: .34 snow .6 11/11 0z: .31 snow .4 11/11 12z: .26 snow .4 11/12 0z: .17 snow .2
  6. No, those maps are counting every flake as sticking which it won’t. I’d be shocked if the city records more than .2
  7. euro still showing some skiffs of snow for the nw burbs. Also, modelling starting to pick up on a little clipper system with some WAA later Thursday could add some more mode flakes.
  8. sorry just seeing this. Damage is already done. Just seed it in spring, you will have weed issues in those spots until the grass is mature enough to be sprayed with a post emerge herbicide. Then around 4th of july put down a grub insecticide and you will be fine
  9. The gefs break down the pna, but the eps are full bore with it still and the Aleutian low still there. As long as that Alaeutian low is there and we don't get low hgts into Alaska that will promote pna ridge. EPS at day 15, you can see it there still. Only thing I'm not keen on is that ridge placement, being on and just off west coast. Core of cold would be west of us, stormy pattern but there will be the potential to cut with that look
  10. Yea, thats why I made it that any snow threat from day 5 out stays in long range thread because of model variability. In all seriousness the shifts ares till within realm of possibilities at day 5 plus. Now if we saw this at day 2, then yea.
  11. Both were no where near lock down mode and never made it inside 4 days so hopefully no one took it to heart. Still was nice to have something to track for a little while
  12. The whole TPV orientation and where it enters the US really hurt this from what it originally looked like. While we still have our wave of low pressure riding up the front because of the shift west of the tpv it brings in se ridging and warms the BL and keeps the storm track west. That change started to occur 2 days ago when the ukmet jumped on it.
  13. way out in weenie gigi-ville, but there is your classic wave 1 displacement of PV
  14. Eps look good still gotta see how the individuals stack up
  15. Euro is like ukmet bit further east with primary low but doing so pushes gradient offshore for 2nd low
  16. tough to tell with ukie, it's been pretty amped last day but looks like it came east a bit, but still not like the gfs. So yes, gfs is outlier right now with the more progressive look, go figure
  17. GGEM looks like the euro as its brings the tpv in further west which allows the first piece of energy to cut west of us, then 2nd piece of energy along front. Still produces some good snow amounts from nw burbs on north, about 1-2 in the city and coastal sections.
  18. Biggest change on gfs is it slid the whole trough axis back east again. With that coming east, it flattens the flow out on the east coast which then allows the piece of energy that was going northwest of us to then come right up at us while the cold air is coming in. Illustrated this on map.
  19. So from original post I talked about two vorts that could get the job done. The vort with the tpv and the piece of energy that ejects out of Baja low. Well over past 24hrs we have seen a shift in the large scale hemispheric trough location westward. So this time yesterday it looked as though that northern stream vort in tandem with a piece of energy off Baja low would develop a wave along the front and bring some light accumulations and another piece of energy off Baja low would get pushed out to sea due to progressive nature of pattern and trough axis. Now 24hrs later with everything bumped westward the first piece of energy from Baja low breaks out ahead of the digging trough in the plains. Because this is much further west it has induced more se ridging and causes that low to cut northwest of us. Since the flow is amplified more so on the east coast it also brings the baroclinic zone for the second piece of energy from the Baja combined with the northern vort. The whole trough axis is is still positive tilted so an area of low pressure will run along the therma gradient of the front. For a bigger system Need this low to form faster but you also don’t want to hold the front up which supplies the cold. So it’s a double edged sword here as usually with anafront. Still looks like a c-3” type event to me right now
×
×
  • Create New...