I have devised a scale to predict how likely it will be a megalopolis city sees a storm 10 inches or greater this winter. 

 

 

I am using the 5 core components to predicting a Northeast Snowstorm. 

 

1)  NAO

2) PNA

3) EPO

4) Cold Source

5) 50/50

 

The above 5 components get the following scale weight, with a wild card added for things such as lead energy in the trough, kickers, complexity of the pattern, something to that affect. 

 

1)  NAO 9

2)  PNA 4

3)  EPO 10

4)  Cold Source  8 

5)  50/50 16

6)  Wild Card 3  points 

 

Add them up divide by 50 multiple times 100 and that's your PERCENTAGE of seeing a 10 plus inch storm in one of the Megalopolis cities. 

 

The worse the component, the lower the score.

 

I will rate the storm at the following intervals:

 

8 days (192 HOURS)

5 days (120 HOURS)

3 days (72 HOURS)

 

The rating is not static over the 4 Megalopolis cities

 

Each may do better based on different variables.  I.E.   The cold source may be bunk for DCA, but serviceable for NYC.  The NAO may be too west for NYC, but good for DCA.  You get the point.

 

AS SUCH, each city must be scaled separately based on historical storms.

 

If you have access to old maps, we can try this out to see how it would work.

 

I think it will help us sort out the model windshield wiper effect. 

 

 

 

 

 

 

This is 48 hours before Juno and then day of Juno. I'm using both since the indexes below aren't always day of indexes. It would be cool to be able to get backwards and see a particular model at  192, 120, 72 but I don't have any of those images so I am going to just rate it as is. Of course, there is likely some hindsight bias in here. I am doing NYC right now

 

1)  NAO 4  - It's east based which is good, but maybe too much.  We get some heights into Iceland but nothing really close.  Nothing over Scandinavia. 

2)  PNA 4  - Stout 

3)  EPO 5 - Higher heights from the PNA do nudge pretty far north, but no closed off epo ridge. 

4)  Cold Source  8  Plenty Cold

5)  50/50 14  You def. low heights where you need it, preventing a cutter

6)  Wild Card 1.5 points.  Miller B tend to go N and E for NYC

 

Total at 48 hours would be about an 73 percent chance for NYC to get 10 or more inches 

 

NYC total was 9.8 inches of snow 

 

 

Great idea and example. Looking forward to this methodology!

a week before the January 2016 storm the AO was at -5sd...I made a post about years with a -5sd usually had a major snowstorm or major cold wave...

4 minutes ago, uncle w said:

a week before the January 2016 storm the AO was at -5sd...I made a post about years with a -5sd usually had a major snowstorm or major cold wave...

So we can use this two ways

 

1)  current state of the atmosphere 

 

And

 

2)  projected

 

 

Both work IMHO 

12/18/10...a week before the post Christmas snowstorm...-5sd ao...

Just now, uncle w said:

12/18/10...a week before the post Christmas snowstorm...-5sd ao...

i'm gonna scale this right now

8 minutes ago, uncle w said:

12/18/10...a week before the post Christmas snowstorm...-5sd ao...

 

 

1)  NAO 7  - Deduction of two points as that block could be suppressive if it doesn't release (we all know it did)

2)  PNA 2 - don't see a trough in the southwest, need to see if it spikes and rolls (we all know it did)

3)  EPO 7 - looks very good with very nice heights where you want it, but not closed off

4)  Cold Source  8 (it was cold that entire month almost and we have a sub pv right where we need it 

5)  50/50 14   it's near textbook

6)  Wild Card 1.5  points at this range i just split the difference as there was nothing at this range that gave anyone a feeling one way or another 

 

 

that's 79 percent chance of 10 inches or more a week out

 

WOW 

5 days before the 12/30/2000 storm...

I like it. 

Awesome idea

2 hours ago, uncle w said:

5 days before the 12/30/2000 storm...

I'll do this for dca phl nyc tonight 

@uncle w

 

 

72 hours please before 12 2000

50 minutes ago, USAwx said:

@uncle w

 

 

72 hours please before 12 2000

 

 

Daily Climate Composites: NOAA Physical Sciences Laboratory

3 minutes ago, uncle w said:

 

Daily Climate Composites: NOAA Physical Sciences Laboratory

I know the link can't do on mobile on road 

7 minutes ago, uncle w said:

 

Thank you 

4 hours ago, uncle w said:

5 days before the 12/30/2000 storm...

1)  NAO 7 - GREAT block, but how will it move?

2)  PNA 3  There is good amplification 

3)  EPO 6 more of an extension of the ridge 

4)  Cold Source  8  brrrrr

5)  50/50 10   displaced to the N and E, that matters for coastal plain

6)  Wild Card 1  points - vort ejecting off the pna - can be very erratic 

 

 

NYC  70 percent chance 10 inches or more at 5 day

 

here is for DCA, PHL and BOS

 

DCA 

NAO 7 - Same as NYC

PNA 2- That is a Miller B pattern out west, generally not favorable for DCA

EPO 6 same

Cold Source 6 just because DCA is further south

50/50 - 5 Not in the best position for DCA historical storms 

wild card  0 - doesn't do well in Miller B

 

52 percent chance for DCA, not a great probability at 5 says 

 

KPHL

NAO 7 - Same 

PNA 4- That is a Miller B pattern out west, can go either way for Philly

EPO 6 same

Cold Source 8 same temp profile as NYC generally in that setup

50/50 - 6  Ok position given Philly being West of the coastal plain

wild card  1 -Miller B tricky

 

64 percent chance KPHL

 

BOS

 

NAO 5 - That is pretty west based, which historically does not favor Boston as much 

PNA 5 - Miller B usually good for Boston

EPO 6 Same

Cold Source 8 plenty cold available 

50/50 2  Not in a good position for Boston being so east 

wild card 2 - Miller B usually good for them

 

56 Percent chance for Boston at this stage 

 

 

 

 

 

in theory, a storm should increase from the 192 hour to 72 hour for its grading

 

that's how you know the pattern is real

 

 

Anyone have any model runs we can use from previous storms? it's fine to do this with re-analysis but would love to do it based on model projections