Stormsfury
Member
ETA, AVN, NGM
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Wintry January 3rd-6th, 2018 Winter Storm The ARCC/Xtreme Weather Special
- Thread starter TheBatman
- Start date
ETA, AVN, NGM
The GFS is clearly shifting the qpf NW with each run. It may be slow but we're still nearly 2 days away from the event. If this slow but steady NW qpf shift were to continue over the next 6-7 runs, it will increase substantially on land considering how much closer the 1"+ qpf is getting. The NW qpf shift has averaged, say 20 miles/run. If that were to continue, that could still be another 140 miles NW shift. With it now being only 50-100 miles to the SE, a 140 mile NW shift would bring it onshore.
Flo
Member
Is this good or bad for CAE?
GeorgiaGirl
Member
I think a pro met on the other board said that the OPs don't make significant shifts in the short range.
Webberweather53
Meteorologist
Lol that's total garbage you only have to go back to early December to realize that's not true and even after the models adjusted they were still wrong even near hour 0
packfan98
Moderator
LovingGulfLows
Member
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- Jan 5, 2017
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I definitely agree they make NW adjustments in the precip field, but I just think the NAM is truly 'best case scenario'. Perhaps I just find it insanely hard to believe this storm will produce 12+ inch amounts deep in GA/SC and 20+ inch amounts in NC. I just think the RGEM is a good compromise between the NAM and globals give or take another 50 mile or so shift. If the RGEM trends towards the super amped NAM, then I'd put all my chips on the NAM.
I would gladly take what the rgem is showing with a nice S to SSE flow at h7 and h85.
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It would not be wise imo to bet on the wet biased NAM literally. In the past when it has been much wetter than model consensus, it has almost always busted way too wet. However, if one were to cut the NAM qpf in half (especially the biblical highest qpf areas), that would imo be a reasonable compromise. After cutting the last few NAM runs' qpf in half, many areas are still hit with a severe winter storm. Also, the NAM has been pretty consistent with its trending at H5 and the surface. Sometimes the NAM likes to jump around wildly from one run to the next and that's when I ignore it for guidance. But in the current case, that's clearly not happening making me think it really may be onto something. Thus I'm not throwing it out....just cutting in half the insanely high qpf and then considering it a a viable option.
I still think that a big key is how the surface low moves from Grand Bamaha Island.
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Meanwhile for the coastal sections, there is huge disagreement not only about qpf but also about the form that that qpf would take %wise. For SAV-CHS, I'm suspecting that a lot that is showing up as ZR will verify as sleet and snow. The ZR just doesn't look reasonable with 850s of only +1 to +2. Climo says that would usually be IP. Moreover, I'm not sure I believe the warmer models' +1 to +2 850s for the first part of the storm. Also, ZR this doesn't seem like a classical ZR setup, with shallow cold air/wedging. Are these models properly taking into account evaporative cooling at 850 and possible dynamic cooling from such a potent system?
packfan98
Moderator
Brad PanovichVerified account @wxbrad 3m3 minutes ago
Here are my 1st thoughts on the Coastal storm Wednesday into Thursday. Very tight gradients for the snow to nothing along I-95 with ice closer to the coast mixed in.
Here are my 1st thoughts on the Coastal storm Wednesday into Thursday. Very tight gradients for the snow to nothing along I-95 with ice closer to the coast mixed in.
packfan98
Moderator
Looks like B rad, is riding the GFS , lol! But he's also the one that 2 days before the big December storm, said no one in NC would see accumulating snow outside the mtns! Whoops!Brad PanovichVerified account @wxbrad 3m3 minutes ago
Here are my 1st thoughts on the Coastal storm Wednesday into Thursday. Very tight gradients for the snow to nothing along I-95 with ice closer to the coast mixed in.
He always does the same thing. Says no no no then dumps it on everyone
Webberweather53
Meteorologist
Yeah it's pretty obvious he's dry humping the global models... lol
I am not quite sure what to believe. Something just tells me that the NAM is off it's rocker, to an extent. You really mean to tell me that the majority of the Global operational and ensemble members are all missing what the NAM sees?
The NAM is a very big deal, and still, even with the RGEM "hinting", is a giant difference versus everything.
The NAM is a very big deal, and still, even with the RGEM "hinting", is a giant difference versus everything.
And the UKMET, and the Euro, and the CMC, and the, . . . shall I go on? Rule for snowfall in the SE: go with the warmest model and the one showing the least amount of snow.
Sorry if it's already been mentioned but tropical tidbits now has a 2.5km hd rgem... unfortunately it cuts off majority of the southeast so no idea what it is doing downstream for those in NC. Also only goes out to 48hours.
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Sorry if it's already been mentioned but tropical tidbits now has a 2.5km hd rgem... unfortunately it cuts off majority of the southeast so no idea what it is doing downstream for those in NC. Also only goes out to 48hours.
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I just did research into the 2.5KM. The only grib files, which are experimental, is that view. Sadly. We can't even make the maps our selves for the SE.
