Hyphnx Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:15 PM, mappy said: ^^ talking about Richmond. Folks, if you are going to be doing model play by play, please please please be specific on what area you are talking about when you do so. Expand On 2/19/2019 at 2:18 PM, Eskimo Joe said: This. Especially if you're on mobile, it's hard to understand where a poster is talking about. Expand Apologies. On 2/19/2019 at 2:16 PM, BristowWx said: in RIC? so you are frozen until that point? interesting I wouldn't have thought that. location dependent there too for sure. Expand This was per the 12zNAM, subject to change. Link to comment Share on other sites More sharing options...
SomeguyfromTakomaPark Posted February 19, 2019 Share Posted February 19, 2019 Initial band at 12z looks fun on 3k. Link to comment Share on other sites More sharing options...
mappy Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:06 PM, snowfan said: 12Z NAM.....DC is over to sleet by 15Z. .3-.4 has fallen by that time, so sticks with the thinking of 1-3/2-4 snow before the flip. Expand not sure what site you are using -- COD has .22 for DC at 15z Link to comment Share on other sites More sharing options...
mappy Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:24 PM, DCTeacherman said: Initial band at 12z looks fun on 3k. Expand Need to be more specific please. Fun for who? DC? Northern MD? Link to comment Share on other sites More sharing options...
Jandurin Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:26 PM, mappy said: not sure what site you are using -- COD has .22 for DC at 15z Expand pivotal says .23-.28 of moisture in the 6hours preceding 15z Link to comment Share on other sites More sharing options...
osfan24 Posted February 19, 2019 Share Posted February 19, 2019 3k NAM has a pretty decent band move through quickly from NOVA to about Baltimore from 5-7 am but then it just falls apart and the run is generally disappointing. Just a couple of inches for most before the flip. Link to comment Share on other sites More sharing options...
jaydreb Posted February 19, 2019 Share Posted February 19, 2019 Close call for OPM. 2-4” is usually not shutdown worthy but the timing is dicey. Link to comment Share on other sites More sharing options...
smokeybandit Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:31 PM, jaydreb said: Close call for OPM. 2-4” is usually not shutdown worthy but the timing is dicey. Expand The word "ice" is there in the forecast. That'll cause them to shut down. Plus the winter storm warnings are already out. Link to comment Share on other sites More sharing options...
Jandurin Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:31 PM, jaydreb said: Close call for OPM. 2-4” is usually not shutdown worthy but the timing is dicey. Expand it's not close at all Snow starts before dawn the storm lasts all day LWX has ridiculous snow numbers they're going to close unless the storm changes completely according to guidance today Link to comment Share on other sites More sharing options...
87storms Posted February 19, 2019 Share Posted February 19, 2019 the key is how long we can hold off on the sleet. given the less than ideal setup, i agree with others that are thinking 1-2/2-4 for dc and tbh i wouldn't be suprised if we ping for a few hours after if the cad is strong enough. the 540 line is all the way up into canada before the precip even gets here. i know that's not the end all, but i don't recall any setups where that's a good thing. Link to comment Share on other sites More sharing options...
zac1245 Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:31 PM, jaydreb said: Close call for OPM. 2-4” is usually not shutdown worthy but the timing is dicey. Expand Dont they usually use the LWX warnings? Which they already put a warning out with more snow than that. Guess they could change it today though. Link to comment Share on other sites More sharing options...
mappy Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:29 PM, Jandurin said: pivotal says .23-.28 of moisture in the 6hours preceding 15z Expand thanks, the .2-.3 range sounds pretty good for DC before the flip. Link to comment Share on other sites More sharing options...
WxUSAF Posted February 19, 2019 Share Posted February 19, 2019 Outside of yesterday’s 12z run, the 3k NAM has been pretty consistent with the front end snow. 2-4”/3-5” depending on latitude and elevation. Link to comment Share on other sites More sharing options...
nj2va Posted February 19, 2019 Share Posted February 19, 2019 3k NAM has about 0.25" for DC before the flip to sleet. Link to comment Share on other sites More sharing options...
osfan24 Posted February 19, 2019 Share Posted February 19, 2019 It has lower totals than almost every other model, which is odd for the NAM, but given the CAD setup, it's hard not to lean on it. And if it can't be used for this type of storm, what can it be used for? Link to comment Share on other sites More sharing options...
WxMan1 Posted February 19, 2019 Share Posted February 19, 2019 12Z NAM3 continues to be underwhelming with the QPF prior to the changeover (~17Z). Generally .15-.20" liquid equivalent. I trust these Ferrier-based SLRs implicitly when riming snow and eventual ptype issues arise, but I still think the continued 1-2" general area-wide average for the cities and I95 corridor through 17Z is lacking with the QPF. I hope so, anyway. Link to comment Share on other sites More sharing options...
WxUSAF Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:41 PM, osfan24 said: It has lower totals than almost every other model, which is odd for the NAM, but given the CAD setup, it's hard not to lean on it. And if it can't be used for this type of storm, what can it be used for? Expand A euro/3k NAM blend is usually a good forecast in a CAD situation like this. That’s where I’d lean. Link to comment Share on other sites More sharing options...
mappy Posted February 19, 2019 Share Posted February 19, 2019 Per the NAM, the northern folks don't flip to pure rain until 00z Thursday, over 1 inch QPF by then. Link to comment Share on other sites More sharing options...
Ji Posted February 19, 2019 Share Posted February 19, 2019 whats frustrating is the 850s are good through 2pm. Is there any chance of a slight error at 700mb? Is that what the canadien high res is seeing? Link to comment Share on other sites More sharing options...
MN Transplant Posted February 19, 2019 Share Posted February 19, 2019 The 12z 3km NAM is frozen in DC through 00z, but only ~0.5" qpf. That is definitely on the low side of what we've been seeing. Link to comment Share on other sites More sharing options...
WxMan1 Posted February 19, 2019 Share Posted February 19, 2019 It still very much feels like a 2-4" thump for most before a layer of sleet and a coating of ice for us along the urban corridor. Hoping for closer to 4" with the snow IMBY, but I have a feeling it'll be closer to 2-3" before the flip. Link to comment Share on other sites More sharing options...
midatlanticweather Posted February 19, 2019 Share Posted February 19, 2019 Jet streak is north - Precip is going north! Link to comment Share on other sites More sharing options...
Scraff Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:34 PM, WxUSAF said: Outside of yesterday’s 12z run, the 3k NAM has been pretty consistent with the front end snow. 2-4”/3-5” depending on latitude and elevation. Expand Where’s your bar set on this one? I’m sure the inquiring minds of the Columbia / Elkridge snow geek crew would appreciate your thoughts. Link to comment Share on other sites More sharing options...
Ji Posted February 19, 2019 Share Posted February 19, 2019 the NAM being dry...what happened to this model? Link to comment Share on other sites More sharing options...
mappy Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 3:00 PM, Ji said: the NAM being dry...what happened to this model? Expand did someone try to unplug and restart it? Link to comment Share on other sites More sharing options...
MN Transplant Posted February 19, 2019 Share Posted February 19, 2019 I know it isn't worth using as a forecasting tool, but as an example of how we at the DC latitude could potentially maximize this storm is the 12z extended HRRR. The sleet line approaches at 15z after 2-3" like the NAM, but then the precipitation ramps up in intensity and effectively "beats back" the mix line so that we end up with 6-7" by 19z. Link to comment Share on other sites More sharing options...
psuhoffman Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:45 PM, Ji said: whats frustrating is the 850s are good through 2pm. Is there any chance of a slight error at 700mb? Is that what the canadien high res is seeing? Expand The issue with the NAM's are where they set up the best banding. They push the best fronto banding north of our area. Even north of my area. After an initial short thump around 7am it focuses the best banding up in PA. You can see the cooling from the heavy band in the morning at 700 mp and then once that lifts north with only lighter rates the WAA takes over and without heavy rates to mix the column we torch at the mid levels. That is how this works. If we stay under heavy banding like the GFS/FV3/GEM/RGEM/HRDRPS/ICON suggest the flip will be delayed a couple hours plus combined with more qpf and we get those 4-8" numbers NWS is pimping. But if the NAM's are right that the best lift and banding ends up to our north in PA, this will be very disappointing to most in here IMO. I am NOT saying I think the NAM is right here...but the NAM progression of this would be a quick 1-3" followed by ice across most of our area. That would probably be considered a fail by most in here considering what the official NWS forecast is right now! Link to comment Share on other sites More sharing options...
high risk Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:52 PM, midatlanticweather said: Jet streak is north - Precip is going north! Expand That's extremely apparent if one looks at the NAM QPF for southern MD. Link to comment Share on other sites More sharing options...
BaltimoreWxGuy Posted February 19, 2019 Share Posted February 19, 2019 ICON looks like a probably a good hit for northern MD...OK for DC but definitely focused from Baltimore N&W Link to comment Share on other sites More sharing options...
Steve25 Posted February 19, 2019 Share Posted February 19, 2019 On 2/19/2019 at 2:51 PM, WxMan1 said: It still very much feels like a 2-4" thump for most before a layer of sleet and a coating of ice for us along the urban corridor. Hoping for closer to 4" with the snow IMBY, but I have a feeling it'll be closer to 2-3" before the flip. Expand You literally took the words right out of my mouth. I'd say in Baltimore it snows approximately from 7 AM- 12 PM. That's 5 hours. I'm not buying the NWS 4-6 inches. That would mean averaging inch per hour rates and during the day I just don't see that happening. I think 2-3 inches is a much safer call and if I'm being honest, I could even see areas near the cities busting low on that, NAM supports that. Typical colder areas could get in the 4-6 inch zone. I expect the sleet to last from 12 PM until about 2 PM at the latest, then freezing rain/rain rest of the day. Honestly when all is done, I think it's going to look a lot like the outcome of last week's storm. Link to comment Share on other sites More sharing options...
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