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2021-22 Global Model QPF/Snowfall Evaluation For PHL. Chubbs 1/22 Event. The GFS Once Again Won The Battle, But Lost (Last Place Finishes) The Details War. EPS 1st With QPF, GGEM 1st With Snow.


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There was no narrow band of heavier precipitation thru PHL to save the models with this event and they returned back to their typical wet bias selves (as far as PHL goes).  So the driest UKMET came in 1st and no stranger to being too wet GGEM came in last. 

 

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  • DebShadow23.0 changed the title to 2021-22 Global Model QPF/Snowfall Evaluation For PHL. 12/28-12/29 Event. The Girl With The Curl UKMET Came In 1st, The Soggy GGEM Came In Last.
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Tom & I want to thank everyone for all the looks this thread gets. Our plans are to keep the same models/ensembles as last season.  We will see if the UKMET remains available, might force a change

euro 10/27 0z: .82 10/27 12z: .91 10/28 0z: .6 10/28 12z: 1 10/29 0z: .94 eps 10/27 0z: 1.22 10/27 12z: .97 10/28 0z: 1.06 10/28 12z: .94  10/29

I think we can go thru 00z on the 26th (this evening) with this one. Plus I am "assuming" an ensemble (hello WEFs) might get us there, can we start the Sunday one with the 12z run today? (25th) F

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On 12/30/2021 at 6:52 PM, tombo82685 said:

euro

12/30 0z: .61

12/30 12z: .49

12/31 0z: .54

12/31 12z: 1.35

1/1 0z: 1.33

eps

12/30 0z: .74 

12/30 12z: .51 

12/31 0z: .77  snow .3

12/31 12z: 1.05  snow .6

1/1 0z: 1.22 snow .2

@tombo82685, I know we can't keep doing the qpf because the rain started, but for this follow up low since all the snow was with it, can we keeping on doing the snow thru the 00z/3rd tonight?

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1 hour ago, DebShadow23.0 said:

@tombo82685, I know we can't keep doing the qpf because the rain started, but for this follow up low since all the snow was with it, can we keeping on doing the snow thru the 00z/3rd tonight?

So you just want the snow aspect, not qpf?

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Just now, tombo82685 said:

euro

1/1 12z: 0

1/2 0z: 2.5

eps

1/1 12z: .2

1/2 0z: 3

They are two separate sheets, so because any snow was going to be tomorrow and not before we can separate them. I knew we are going to keep precipitating on us GFS was going to screw this one up because it had no clear break which exists.

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1 hour ago, tombo82685 said:

Am I stopping with 0z run or going to 12z run today?

Stopping with the 00z run, it did start to snow before 12z even though it didn’t measure.

BTW we can start Thursday night event with 00z run this night.

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First let's give credit where credit is due with the snow to the GFS which went northwest first with the wave and had measurable snow reach PHL one sounding run (48hrs before onset) sooner than the GGEM or Euro.  Now if we could only have stopped there.

The binary will it or wont it aside, the GFS came in last place for the 2nd most inaccurate rainfall and the most inaccurate snowfall forecast for PHL.  Rainfall went to the EPS (getting hot at the right time) and snowfall went to the UKMET.  I couldn't get the EPS for it, but I went farther south and east to ACY to see how the models did with snowfall there.  13.0" at ACY, GFS couldn't be inaccurate there.  Wrong.  It came in last place again because it was too snowy. Not a surprise the UKMET did poorer in ACY, it was too conservative (often is, for a wet model I don't know how it does that) with the snowfall.  Here the OP ECMWF as most accurate (EPS was n/a).

So in a sample of one so far the GFS does ok with qpf when the low pressure systems are traversing Canada, not so much when they are closer to PHL.  

Lastly the GFS made this an impossible to separate precipitation event because it had the last wave initially coming in on Sunday night with the you know, not much break in precipitation. In reality it was.  It should have had a leg up on the other models (qpf and snow) because it had both first, but it did not.

 

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  • DebShadow23.0 changed the title to 2021-22 Global Model QPF/Snowfall Evaluation For PHL. 1/1-1/3 Events With A Special Look At ACY. UKMET Most Accurate With Snow @PHL, OP EC For ACY; QPF Went To EPS, GFS Brought Up The Rear.

euro

1/4/0z: .13 snow 1.3

1/4/12z: .09 snow .9

1/5 0z: .16  snow  1.6

1/5 12z: .19 snow  1.9

1/6 0z: .25 snow 2.5

1/6 12z: .25 snow 2.5

1/7 0z: .3 snow 3

eps

1/4/0z: .3 snow  2.6

1/4/12z: .18 snow 1.7

1/5 0z: .16  snow 1.6

1/5 12z: .2 snow 2

1/6 0z: .27 snow 2.7

1/6 12z: .25 snow 2.5

1/7 0z: .28 snow 2.8

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Unfortunately (or fortunately for the GGEM) the 1/5 event fell thru the cracks.  Looking at the snowfall forecasts for tomorrow and having to subtract the predicted qpf for 1/5, there was a GGEM run that predicted 0.14" of an inch for PHL. It was not the only measurable run it had. No other models/ensembles met our 0.10" threshold. So without a doubt the GGEM came in last by backing heavier precipitation too much to PHL, not sure which OP models had no measurable at all. 

GGEM you can mail those cigars to.....

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On 1/4/2022 at 7:44 PM, tombo82685 said:

euro

1/4/0z: .13 snow 1.3

1/4/12z: .09 snow .9

1/5 0z: .16  snow  1.6

1/5 12z: .19 snow  1.9

eps

1/4/0z: .3 snow  2.6

1/4/12z: .18 snow 1.7

1/5 0z: .16  snow 1.6

1/5 12z: .2 snow 2

We can get seven runs out of this, we can go thru the 00z/7th run tonight.

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  • DebShadow23.0 changed the title to 2021-22 Global Model QPF/Snowfall Evaluation For PHL. Subjective Look At 1/5 Event. GGEM Went West & Ended Last.
On 1/4/2022 at 7:44 PM, tombo82685 said:

euro

1/4/0z: .13 snow 1.3

1/4/12z: .09 snow .9

1/5 0z: .16  snow  1.6

1/5 12z: .19 snow  1.9

1/6 0z: .25 snow 2.5

1/6 12z: .25 snow 2.5

eps

1/4/0z: .3 snow  2.6

1/4/12z: .18 snow 1.7

1/5 0z: .16  snow 1.6

1/5 12z: .2 snow 2

1/6 0z: .27 snow 2.7

1/6 12z: .25 snow 2.5

We can start the Sunday event with the 00z run this morning (7th).  Yeah the include the 00z/7th for the snow also. NAPOLEON 2100-1 TIMBERWOLF ECONOMIZER 26 INCH FREE-STANDING SMALL WOOD BURNING STOVE - BLACK

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Using the standard 10:1 ratio does not work for every event.  Sometimes it makes modeling look better than it was.  With this event, other than the UKMET it made the wet forecast bias more accurate than it was with the snow.  Yes if we were evaluating ABE or even Harrisburg, results probably would have been different.  It is not uncommon for different models/ensembles to do better in different areas.

When it came down to sounding runs with qpf forecasts the OP ECMWF came closest for PHL. Yes earlier runs had the low and heavier precipitation too far east and later runs were too wet, but not as wet as our last place finisher.  The OP GFS came last.  All 7 sounding runs of the GFS was wetter than the GEFS, not a place you want to be and the GFS forecast twice the precipitation amount that actually fell.  With snowfall using the 10:1 ratio the GEFS came in first and the UKMET came in last.  Its snow hole around Philadelphia was too dry and big.

A pattern I have noticed with the OP ECMWF it is saving its most inaccurate forecasts for last.  The last two snow events, they both occurred within 24 hours of go time.  It's almost too much of a correction of what initially has been a too far offshore bias.

 

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On 1/7/2022 at 8:00 AM, tombo82685 said:

euro

1/7 0z: .24

1/7 12z: .39

1/8 0z: .36

1/8 12z: .33

1/9 0z: .32

eps

1/7 0z: .24

1/7 12z: .34

1/8 0z: .34

1/8 12z: .29

1/9 0z: .34

We can include the 12z run.

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  • DebShadow23.0 changed the title to 2021-22 Global Model QPF/Snowfall Evaluation For PHL. Everybody Gets Snow 1/7 Event. EC (1st) Saves Its Best QPF For This Event, The Too Wet GFS Was Last. Snow GEFS (Lower Than GFS) 1st, Snow Hole UKMET Last.

The bizarre cold season continues.  Yet another cold frontal passage with a low pressure system passing near/thru Hudson Bay.  Right on cue the driest model (GGEM) ends in first and the wet bias with synoptic patterns like this ECMWF ends in last.

BTW (Only) The GEFS had a couple of runs with a couple of tenths of snow, rain changing to snow before ending.  I gave at the office and the check is in the mail.

 

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  • DebShadow23.0 changed the title to 2021-22 Global Model QPF/Snowfall Evaluation For PHL. Back To The Bizarre Cold Season 1/11 Event. GGEM In 1st & OP EC In Last.

euro

1/14 0z: 1.25  snow 1.5

1/14 12z: 1.15 snow 1.8

1/15/0z:  1.03 snow 1.5

1/15 12z: 1.22 snow 1.5

1/16 0z: 1.02   snow 1.2

1/16 12z: 1.14 snow 1

eps

1/14 0z:  1.08 snow 2

1/14 12z: 1.02  snow 1.6

1/15/0z: 1.05 snow 1.3

1/15 12z: 1.07 snow 1.5

1/16 0z: 1.15  snow 1.2

1/16 12z: 1.14  snow 1

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On 1/14/2022 at 10:58 PM, tombo82685 said:

euro

1/14 0z: 1.25  snow 1.5

1/14 12z: 1.15 snow 1.8

1/15/0z:  1.03 snow 1.5

1/15 12z: 1.22 snow 1.5

eps

1/14 0z:  1.08 snow 2

1/14 12z: 1.02  snow 1.6

1/15/0z: 1.05 snow 1.3

1/15 12z: 1.07 snow 1.5

I think the 12z run today (16th) is going to be the last one, starting too soon to 00z.  I will let you know about Wednesday.

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On 1/14/2022 at 10:58 PM, tombo82685 said:

euro

1/14 0z: 1.25  snow 1.5

1/14 12z: 1.15 snow 1.8

1/15/0z:  1.03 snow 1.5

1/15 12z: 1.22 snow 1.5

eps

1/14 0z:  1.08 snow 2

1/14 12z: 1.02  snow 1.6

1/15/0z: 1.05 snow 1.3

1/15 12z: 1.07 snow 1.5

Yeah 12z today, 16th last one. 00z run tonight to start the Wed/Thu one.

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euro

1/17 0z: .15

1/17 12z: .07

1/18 0z: .18  snow .4

1/18 12z: .21 snow .6

1/19 0z: .49   snow 1.8

1/19 12z: .41 snow  1.3

1/20 0z: .37 1.1

eps

1/17 0z: .16 snow .3

1/17 12z: .16 snow .1

1/18 0z: .22  snow .8

1/18 12z:  .26 snow 1.1

1/19 0z: .33  snow 1.5

1/19 12z: .35 snow 1.1

1/20 0z: .35 snow  1

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  • DebShadow23.0 changed the title to 2021-22 Global Model QPF/Snowfall Evaluation For PHL. Chubbs 1/22 Event. The GFS Once Again Won The Battle, But Lost (Last Place Finishes) The Details War. EPS 1st With QPF, GGEM 1st With Snow.

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