Jump to content



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!


  • Content Count

  • Joined

  • Last visited

  • Days Won


Posts posted by tombo82685

  1. 1 hour ago, tombo82685 said:

    eps, can see we are on the nw flow side of the trough, would need that to kick west some. It does have potential if it can shift west a bit more to give room to run corner


    So let me explain what I mean by to deep into the trough. First off I have a blank map of the USA to illustrate what I'm saying. So the jet stream is the flow of air from west to east, sometimes its zonal (west to east) or meridonal (north/south) So disturbances enter the west coast and either dive down at the base of a trough or go up over a ridge. For this instance we will use a ridge. So when you have a ridge the disturbance goes up over the ridge then dives down the backside of the ridge, or front side of the trough. These usually are weak systems, clippers most likely. Once at the base of the trough is when they can really start to amplify as they tap warmer moist air, then strengthen on their way northeast on the front side of the trough. blank-map-of-the-continental-united-states.PNG.70e0c6ec393f68726bf8c9d0e701fc41.PNG


    Now lets use the eps h5 map. You can see our trough location off the west coast and the ridge axis over the rockies and then trough axis directly over us. So we are basically smack dab in the middle of the trough, basically where a disturbance dives down and starts it bend to turn northeast. Thats why we need the trough axis to push further west so we can be on the upwards side of the trough and not smack dab in the middle of it. 


    • Like 1

  2. 2 minutes ago, Baseball0618 said:

    Completely agree with this sentiment.  These usually trend wetter versus more white for us given the NAO and ridge positioning out west.   Thinking our best potential comes closer to Xmas for our first real snow threat as the ridge out west starts to move east.  

    Nao is actually negative for this which is good and the only reason we are talking possible frozen. The pacific is the issue 

  3. Overall trend with 0z eps to 6z eps. TPV and 50/50 low pretty stable. Greenland ridging a bit stronger, which does help lower hgts a bit more in the east. Energy out west a bit slower/stronger. Which allows for a bit more return flow. You can see in the area I circled comparing 0z to 6z how the blue color get lighter on 6z. That shows some eps members having a bit stronger ridging out ahead of storm and most likely stronger primary cutting west. 


  4. 33 minutes ago, irishbri74 said:

    Let’s see if this has some legs. Some subsidence entering the IOD region , and that standing wave becoming not so standing.(that’s a scientific term 😂). 

    weak signal for now, but it would be a positive going forward. Get some forcings back into the west Pac, which would improve and stabilize a -EPO pattern. We’ll revisit this beginning of next week to see how it looks. 


    just to add what we’re looking at. Subsidence is the orange in the bottom left. Lift (blue) into the 120-140 region. We want that big blue/purple blob over 60E to dissipate/weaken. 

    Yea there looks to may be finally a legit mjo wave try to emerge around end of dec in phase 5/6, which is warm for us but would most likely go into colder phases

  5. 24 minutes ago, Rainshadow said:

    This may help/hurt.  Trend toward strengthening 850mb jet, tightening the thermal gradient (fgen); but then staring at a 50kt+ southerly jet pretty much guarantees a change to non snow.  Of course the warmth comes above this first.


    Yea the tightening of the thermal clash should help with WAA precip. Just hoping for some front end snow. Never thought this was a snowstorm potential for us with how the pacific looks

  6. On 0z eps compared to 12z eps, most of the main features were pretty stable. 50/50 low didn't show much change, except that it was a bit bigger. TPV location remained the same except it stretched out more. The biggest issue continues to be the western energy how to deal with that. The eps trended a bit stronger and slower with it compared to 12z, both things we don't want. What did help this run to mitigate that was a stronger greenland ridge so it pinned down the 50/50 low better. Because of that you can see the flow off the east coast gets compressed more with how the stronger greenland blocking pushes down on the heights on the east coast.  As shawn alluded too, that needs to come out weaker and disjointed to provide a good winter storm. If it comes out strong it's going to pump the ridge to much out ahead of it and it will cut way west with how the pacific pattern looks. 





    • Like 1
  • Create New...