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Pattern April Chasing ???⛈⛈⛈

The evolution of this ULL will be critical. The track of it, strength and depth of cold air will change significantly the next few days as models struggle to figure it out as they typically do with these storms. GFS is a middle ground while the euro/icon agree and the 00z fv3/cmc are more suppressed with it.
 
0Z GFS ? gives snow in parts of NC outside of mountains!28E3079D-0263-4E5F-AA22-0D36F5585610.png
 
Typical struggle in spring, BL temps, this would still support a R/S mix but no sort of accumulating snow, I’m pretty sure seeing snowflakes outside the mountains with this possible event is a win
4282054A-0E67-4CE9-8F4A-633A0098B868.png
 
GaWx said:
0Z FV3 warmed up some on 4/1 to no surprise.
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Longwave trough axis is trending weaker aswell, which means less amped/flatter storm and less CAA if any, what I’m wondering is whether the FV is to suppressed, gefs/eps and euro will be very much telling
 
Here a ?, there a ?, everywhere a ? ? ....0Z EPS for your viewing pleasure:
AD0A10A8-C246-4A0F-95FA-40F89FC8D7DB.png
 
I dont know each consecutive run of the euro and its ensemble widens the snow and puts more down each run ... keep up the trend
 
I mean , all the models can’t be wrong?? Can they?
 
Given time of year, early call would be 3”+ mountains, 1-3” foothills, wintry mix to rain elsewhere. Mostly NC.
 
From what I can tell, the Ensembles are beginning to converge, with the overnight runs leaning toward the less snowy solution. The EPS seemed to be a 50/50 split of snow up here with a majority of the 25 showing at least an inch or two from what I can tell. 12Z will determine if a thread should be started.
 
Nick_boynton_ said:
Skeptical ? let’s see the GEFS
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Remember all of those crazy cold FV3 runs with low to mid 30s for over 24 hours straight deep into GA/SC in yesterday’s runs? That 0Z run that I referred to and now the 6Z run are way, way warmer, which of course is no surprise due to strong cold bias. Check out the 6Z FV3 ?, which is similar to the 0Z FV3 and suddenly has NO SE snow other than a little along the TN/NC border. It isn’t just the TT snowfall algorithm that is off. There is a horrible cold bias in addition to that inherent in the model, itself.
7560795D-2E88-43A2-9F54-6B1402CCBF8A.png
 
GaWx said:
Remember all of those crazy cold FV3 runs with low to mid 30s for over 24 hours straight? That 0Z run and now the 6Z run are way, way warmer, which of course is no surprise due to strong cold bias. Check out the 6Z FV3 ?, which is similar to the 0Z FV3 and suddenly has NO SE snow other than a little along the TN/NC border:
View attachment 18128
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Main reason there isn't any snow is because it's far more suppressed than the Euro and GFS as well. The moisture doesn't even make it north of deep south GA and Columbia and a strong low doesn't form until way later when it's OTS. I'm inclined to not believe this since we have seen the FV3 have horrible biases in terms of H5 as well.
 
GaWx said:
Remember all of those crazy cold FV3 runs with low to mid 30s for over 24 hours straight deep into GA/SC in yesterday’s runs? That 0Z run that I referred to and now the 6Z run are way, way warmer, which of course is no surprise due to strong cold bias. Check out the 6Z FV3 ?, which is similar to the 0Z FV3 and suddenly has NO SE snow other than a little along the TN/NC border. It isn’t just the TT snowfall algorithm that is off. There is a horrible cold bias in addition to that inherent in the model, itself.
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The problem is the one ForsythSnow mentioned. The Fv3 now has basically no precip in those areas as it has shifted SE with the precip shield and overall system. It is also much weaker too hence less evaporative and dynamic cooling taking place. Certainly the Fv3 has a cold bias but the reason for it warming so dramatically the past two runs is due to less precip to work with and a weaker/suppressed system. The Euro and GFS would show similar if they shifted to a weaker/suppressed system as well. Right now models are still split with some weaker/suppressed ideas like the Fv3/CMC while the ICON and Euro are a bit stronger. The GFS right now is probably a middle ground blend of these two camps. Since this is a system that will rely on timing, dynamic cooling and a little evaporative cooling to cool things down it's critical where the precip shield sets up and how strong this system is.
fv3p_apcpn24_us_fh108_trend.gif
 
It's worth noting the usually suppressed NAVGEM has a fairly strong coastal that is close to the coast.

1553865994538.png
 
GaWx said:
Remember all of those crazy cold FV3 runs with low to mid 30s for over 24 hours straight deep into GA/SC in yesterday’s runs? That 0Z run that I referred to and now the 6Z run are way, way warmer, which of course is no surprise due to strong cold bias. Check out the 6Z FV3 ?, which is similar to the 0Z FV3 and suddenly has NO SE snow other than a little along the TN/NC border. It isn’t just the TT snowfall algorithm that is off. There is a horrible cold bias in addition to that inherent in the model, itself.
View attachment 18128
Click to expand...
I don’t think that was the cold bias I think that’s just the Fv3 not showing the storm.. it’s not amped at all and doesn’t really turn up the coast just kind of goes out to sea
 
This storm has a very delicate balance... You want it strong enough so that it will be close to the coast and throw enough heavy precip back into the colder air aloft to hopefully drop some snow in some areas but not too strong that it cuts inland or too weak that it's dry/suppressed.
 
Early in the GFS, looks good, cold looks solid, you can see moisture pooling in the gulf and S Tx
 
Pretty late in the game to have one go poof like that. I guess it was really only the EURO an ICON that had big precip into the mountains though. GFS fam and CMC were pretty suppressed the whole time from what I recall.
 
Nomanslandva said:
Pretty late in the game to have one go poof like that. I guess it was really only the EURO an ICON that had big precip into the mountains though. GFS fam and CMC were pretty suppressed the whole time from what I recall.
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Yeah GFS has had precip confined to I-95 in NC and east of there for the most part and is shifting suppressed more now. Fv3 last 3 runs has been very suppressed and CMC has been consistently offshore. This one could still swing back NW though as we get closer but right now the trend today has been for a suppressed look. Not only would this allow temps to be warmer it would also keep the bulk of the precip offshore.
 
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