December 19-20 Talking Points - Part 3

[tornadojay]

I've got good news and bad....my forecast model hits the area with heavy snow....the bad news it aint to good...

cool! You have your own model! You have a name for it, by the way??

[whiteoutwx1796]

Yep,should keep the below normal tendency in our temps going.

In essence that's not even a LA NINA pattern if the southeast is going to be cool like that.

[Snowfreak09]

From a trusted met on another board :

QUOTE (Jimrin1967 @ Dec 17 2010, 07:59 PM) This is STILL not an easy forecast by any means......despite what all of the models show. What do they show? They should the Gulf of Alaska low moving southeast towards the Pacific coast and flattening out the western ridge. To this point, it is not. In fact, compare last night's 24 hour ECMWF with this morning's 24 hour. Despite the final solution of a storm off the coast, last night's run was already flattening the ridge at 24 hours. Today at 24 hours (which is 12 hours later) there is still amplification and it takes until the 48 hour on the 12Z ECMWF to flatten the ridge. What if...just what if...the Gulf of Alaska low continues to move south and the timing of the flattening is pushed back even more? The models also show the southern branch disturbance falling apart in about 6 hours. It was supposed to be weakening during these last 6 hours. Its not. Those are two EXTREMELY important pieces that we have to see how it plays out in real time data.

[rgwp96]

cool! You have your own model! You have a name for it, by the way??

yea its called the JB model

[tornadojay]

Here's what HPC says in their latest update:

EARLY IN THE PERIOD MODELS HAVE HAD A GOOD DEAL OF DIFFICULTY IN

THE AMPLITUDE ALBEIT SUBTLE OF SHORTWAVE ENERGY COMING TO THE EAST

COAST INDUCING COASTAL CYCLOGENESIS. STORM TRACKS OF THE MODELS

HAVE BEEN FLIP FLOPPING RESULTING IN LOCATIONAL DIFFERENCES OF

300-400 MILES FROM RUN TO RUN AS THE SYSTEM DEEPENS IN THE

NORTHWEST ATLANTIC. THIS RESULTS IN CRITICAL DIFFERENCES IN PCPN

AMOUNTS. HAD USED A LAGGED AVERAGE FORECAST TO ACCOUNT FOR THESE

DIFFERENCES AT THE DAY 5 AND BEYOND RANGE BUT WITH THE CLOSER

RANGE OF 4 DAYS AND UNDER THE OPERATIONAL DETERMINISTIC MODELS

SHOULD DO BETTER. TODAYS GROUPING OF LOW PRESSURE CLUSTERING AT

DAY 4 TUES IS A GOOD 350-400 NM EAST OF YESTERDAYS WELL AGREED

UPON 12Z CONSENSUS. HAVE BLENDED MULTI MODELS FOR DAYS 3 WITH A

TREND TOWARDS THE 06Z GFS/ECMWF ENS MEAN AND GFS ENS MEAN LATER IN

THE PERIOD. MAIN EFFECT OF THE NORTHWEST ATLC STORM WILL BE OVER

ERN MA AND COASTAL ME WITH SNOW AND HIGH WINDS MONDAY INTO

TUESDAY.

[bluewave]

In essence that's not even a LA NINA pattern if the southeast is going to be cool like that.

It's what you get when you add extreme blocking to the La Nina.

[famartin]

From a trusted met on another board :

QUOTE (Jimrin1967 @ Dec 17 2010, 07:59 PM) This is STILL not an easy forecast by any means......despite what all of the models show. What do they show? They should the Gulf of Alaska low moving southeast towards the Pacific coast and flattening out the western ridge. To this point, it is not. In fact, compare last night's 24 hour ECMWF with this morning's 24 hour. Despite the final solution of a storm off the coast, last night's run was already flattening the ridge at 24 hours. Today at 24 hours (which is 12 hours later) there is still amplification and it takes until the 48 hour on the 12Z ECMWF to flatten the ridge. What if...just what if...the Gulf of Alaska low continues to move south and the timing of the flattening is pushed back even more? The models also show the southern branch disturbance falling apart in about 6 hours. It was supposed to be weakening during these last 6 hours. Its not. Those are two EXTREMELY important pieces that we have to see how it plays out in real time data.

That's called grasping at straws.

[IsentropicLift]

that has to be one of the lowest confidence forecasts I can remember and the first one at that which seemed to bash all of the global models together....I hate to give myself false hope but this may come down to nowcasting.

[KEITH L.I]

what grade would you give the Euro on this storm..an F..and i'm being nice

[famartin]

that has to be one of the lowest confidence forecasts I can remember and the first one at that which seemed to bash all of the global models together....I hate to give myself false hope but this may come down to nowcasting.

Not really. I now forecast little to no snow in New Jersey on Sunday. And I'm quite confident on that.

[famartin]

what grade would you give the Euro on this storm..an F..and i'm being nice

7 of the last 9 runs have had ZERO precip for I-95. That's actually not that bad, compared to quite a few GFS runs which had something.

[ag3]

that has to be one of the lowest confidence forecasts I can remember and the first one at that which seemed to bash all of the global models together....I hate to give myself false hope but this may come down to nowcasting.

No. Model concensus is clear now. Yesterday you could have made this statement. But today, its a clear forecast. There is no low confidence.

[rgwp96]

7 of the last 9 runs have had ZERO precip for I-95.  That's actually not that bad, compared to quite a few GFS runs which had something.

i dont think 1 or maybe it was one gfs run that gave me .10 of precip.  euro had me at .5 one run than 1.75 the next

[Edge Weather]

I believe 9 out of the last 9 runs of the NOGAPS have had zero precip for I-95.

7 of the last 9 runs have had ZERO precip for I-95. That's actually not that bad, compared to quite a few GFS runs which had something.

[Riptide]

No. Model concensus is clear now. Yesterday you could have made this statement. But today, its a clear forecast. There is no low confidence.

I still think smaller changes within intensity and track are still in the cards(25-50 miles) and this makes a big difference for coastal areas.

[SnowGoose69]

that has to be one of the lowest confidence forecasts I can remember and the first one at that which seemed to bash all of the global models together....I hate to give myself false hope but this may come down to nowcasting.

Given how much of a miss most models are its probably a safe bet this misses but given the wild swings and how much convective issues there has been on many of the NAM runs and some GFS runs off the SE coast there is the possibility there could still be some sort of wild last minute change on this event....normally with this sort of modeling this close you're 98% a miss...in this case maybe its 88-90%.

[famartin]

i dont think 1 or maybe it was one gfs run that gave me .10 of precip. euro had me at .5 one run than 1.75 the next

There were several GFS runs mixed in that edged precip up into I-95. Yeah, not a lot, but they still did. Aside from those two EC runs you mention, the rest had zilch.

[famartin]

12Z EC has not a drop of precip for NJ all the way through 240. That's epic.

[CooL]

12Z EC has not a drop of precip for NJ all the way through 240. That's epic.

Cold and dry? Ha, that sounds familiar

[nynjpaweather]

Talk about a model flip in a span of 24 hours! Blizzard and snow storms to nothing for 24 hours. If this was on the GFS, no one would be surprised.

[IsentropicLift]

taking a loot at the HPC Surface Analysis/Infrared satellite loop it looks to me on the last frame as if their is an occluded front drapped all along the coast, with low pressure trying to form closer to the TX coast line. I don't remember any mention of this front in the discussion.

[KEITH L.I]

12Z EC has not a drop of precip for NJ all the way through 240. That's epic.

I guess it's gonna be right..because it's the King ,that is always right 10 days out..that model sucks long range like every other model, next

[chubbs]

12Z EC has not a drop of precip for NJ all the way through 240. That's epic.

Looks like it is getting ready to warm-up and rain post day 10 with big plains low. Only good thing is - it will change at 00z.

[RutgersWx92]

7 of the last 9 runs have had ZERO precip for I-95. That's actually not that bad, compared to quite a few GFS runs which had something.

Yeah, but it is important to note that the two runs that did have precip for I-95 were only three days from the event. The GFS runs that were comparable to those two Euro runs were farther out IIRC.

[blazess556]

We should start looking toward the miller b midweek

[famartin]

Yeah, but it is important to note that the two runs that did have precip for I-95 were only three days from the event. The GFS runs that were comparable to those two Euro runs were farther out IIRC.

I think the 00Z Thursday GFS had about the same as the EC. We got excited because it was a big change for the EC... nothing different for the GFS.

[IsentropicLift]

still have a 50% chance of snow for sunday and sunday night for my area and I'm in Morris county, a lower probability area to begin with. It was even updated after the Euro came out. I'm confused. I wonder if perhaps they feel as if the models will come back just enough to bring some light snow.

[SnowGoose69]

Looks like it is getting ready to warm-up and rain post day 10 with big plains low. Only good thing is - it will change at 00z.

The Euro has been trying to do that for some time now...eventually this pattern will break down for a bit...likely during that classic mid-January period when it always seems to do it for a week or two...if the Euro has one weakness compared to the GFS its that it often tries to break patterns down near the end of its run while the GFS is often quite good in the 10-16 day period with the general regime, especially if it shows the same overall pattern for multiple runs in a row.

[IsentropicLift]

If anyone cares...the 21z SREF shifted its 0.25 line about thirty miles to the NW. Would give far eastern sections a few inches and a coating into NJ.

[famartin]

still have a 50% chance of snow for sunday and sunday night for my area and I'm in Morris county, a lower probability area to begin with. It was even updated after the Euro came out. I'm confused. I wonder if perhaps they feel as if the models will come back just enough to bring some light snow.

Just a note that the "update time" listed doesn't mean that the WHOLE forecast was updated. It just means that at least one teeny tiny element of the forecast was updated. Usually, significant forecast changes beyond the first or second period are only made at the "scheduled" times... i.e., 4AM/4PM.