Jump to content
  • Member Statistics

    17,586
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

Weekend Mixed Bag of WTF storm thread


Ji

Recommended Posts

  • Replies 1.9k
  • Created
  • Last Reply

amped solutions have mostly failed this year

That's because of the NAO/AO combo.  In this pattern anything coming at us from the west we are better off being a weak wave.  Now the storm later next week coming up from the eastern Gulf...that one we can hope amps up because its starting off far enough east that cutting is not as much a threat. 

Link to comment
Share on other sites

GFS 18/0z run forecast for 18z on Saturday had the low as a 998 over Amarillo.  Today's 19/12z run has it as a 1010mb near Texarkana.  High off the coast is also farther north and east.  

 

Been a huge deamplification trend within 72 hours for almost every storm this year (that's not hitting Boston).  

Link to comment
Share on other sites

GFS 18/0z run forecast for 18z on Saturday had the low as a 998 over Amarillo.  Today's 19/12z run has it as a 1010mb near Texarkana.  High off the coast is also farther north and east.

 

Been a huge deamplification trend within 72 hours for almost every storm this year (that's not hitting Boston).  

To me, that is the ticket for us.

Link to comment
Share on other sites

Not that it matters much at this range, but there is that GD Shen. Valley dry slot again on the GFS map.  WTF?

This is basically an overunning with SW flow, that means your winds are downsloping off the 4,000 ft mountains over WV to your southwest.  In this case it makes perfect sense to see a rainshadow or "snowshadow" effect.  I had the same happen when I was at Penn State anytime the winds were out of the SW off the Allegheny mtns. 

Link to comment
Share on other sites

6:1 snow  w/ temps in the teens?

 

Goodness, that makes Monday's ratio debacle look like dendrite heaven.

ratios are overrated.  Trust me!  Up here all my snows have been high ratio fluff...then the next day half of it sublimates when the sun hits it no matter how cold, then the other half blows away into the woods or sides of buildings.  Denser snow holds better afterwards.  I would take 4" of low ratio snow over 6" of fluff every time. 

Link to comment
Share on other sites

Based on the GFS trends (supported by the 12Z NAM)...It wouldn't surprise me to see this as a mainly snow event (2-4/3-5" accums). We've seen these types before coming out of an arctic surge. Initial WAA pcpn is predominantly snow...maybe not the best dendritic profile aloft but still 10-1/9-1 snow...then the pcpn shuts off as light sleet/fzra or even drizzle as the layers aloft continue to warm (while surface temps stay close to freezing with the fresh snow, lack of strong southerly/warm surge, and thus some lingering in-situ CAD wedging).

If we want all snow or predominantly snow, we definitely want these sheared trends in the models when we can cash in with the first batch of precipitating WAA/isentropic ascent.

Link to comment
Share on other sites

This is basically an overunning with SW flow, that means your winds are downsloping off the 4,000 ft mountains over WV to your southwest.  In this case it makes perfect sense to see a rainshadow or "snowshadow" effect.  I had the same happen when I was at Penn State anytime the winds were out of the SW off the Allegheny mtns. 

 

Makes sense, though still frustrating as every event this year here has seemingly been significantly drier than the region.  It probably usually is though.

 

I realize the BR mountains to the east aren't as high, but why is there no similar rain shadow effect to the east? 

Link to comment
Share on other sites

Makes sense, though still frustrating as every event this year here has seemingly been significantly drier than the region.  It probably usually is though.

 

I realize the BR mountains to the east aren't as high, but why is there no similar rain shadow effect to the east? 

There is, just not as pronounced, but when there are clippers a lot of times the precip redevelops east of the blue ridge, and gets heavier as you move east from the blue ridge...sometimes DC will get more qpf then IAD because of the shadow effect in those cases.  But as you said those mountains are not as high so its less of an effect.  This year sucks because of lot of our events have been weak waves from the west and thus you get the shadow effect.  You really need a system that is amping up to our southeast where you have northeast flow.  Due to the NAO we have not had many of those as systems that do amp in this pattern are going to want to cut.  We would need perfect timing of something to dig down and phase at just the perfect spot over the southeast to get that to work out for us.  (next week maybe)

Link to comment
Share on other sites

There is, just not as pronounced, but when there are clippers a lot of times the precip redevelops east of the blue ridge, and gets heavier as you move east from the blue ridge...sometimes DC will get more qpf then IAD because of the shadow effect in those cases.  But as you said those mountains are not as high so its less of an effect.  This year sucks because of lot of our events have been weak waves from the west and thus you get the shadow effect.  You really need a system that is amping up to our southeast where you have northeast flow.  Due to the NAO we have not had many of those as systems that do amp in this pattern are going to want to cut.  We would need perfect timing of something to dig down and phase at just the perfect spot over the southeast to get that to work out for us.  (next week maybe)

 

Interesting and educational.  Appreciate the explanation.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...