Deck Pic Posted February 18, 2019 Share Posted February 18, 2019 10:1 Kuchera Link to comment Share on other sites More sharing options...
RDM Posted February 18, 2019 Share Posted February 18, 2019 Interesting how the WSW is still cutoff sharply at the M-D. Based on the consensus being dialed in across the models and runs, expected NWS to expand it further N by now, if not at the initial posting. Maybe the next update later this afternoon will see a northward expansion. Link to comment Share on other sites More sharing options...
dsnowman Posted February 18, 2019 Share Posted February 18, 2019 Regarding the two camps (NAM/EURO and GFS/ICON, I'm still paying attention to the globals and how they are handling the SE ridge. The NAM has the moisture feed from the gulf going around a strong SE ridge into TX and OK and then heading towards our area (why it's projecting in MD/PA). The GFS on the other hand has a much quicker turn towards our area (thus a direct DC hit), mainly because it sees the SE ridge relaxing somewhat. I'm leaning more towards the GFS right now in terms of placement of heaviest precipitation (PA versus DC). Link to comment Share on other sites More sharing options...
mappy Posted February 18, 2019 Share Posted February 18, 2019 2 minutes ago, RDM said: Interesting how the WSW is still cutoff sharply at the M-D. Based on the consensus being dialed in across the models and runs, expected NWS to expand it further N by now, if not at the initial posting. Maybe the next update later this afternoon will see a northward expansion. Watches/Warnings come from the individual weather offices. LWX went with a watch -- State College had advisories this morning, but i guess that was for the overnight stuff. I see they have nothing now. Link to comment Share on other sites More sharing options...
packfan98 Posted February 18, 2019 Share Posted February 18, 2019 Quite a bit more freezing rain on this run of the Euro compared to 0z. Looks like at least .25" for most with more NW of DC proper (.7"). Link to comment Share on other sites More sharing options...
JakkelWx Posted February 18, 2019 Share Posted February 18, 2019 Going conservative for my area of a 1 or 2 inch thump before ice then rain. Link to comment Share on other sites More sharing options...
Bazooka Joe Posted February 18, 2019 Share Posted February 18, 2019 New to the forum and really enjoying the discussion. I think this storm might surprise some forecasters relative to the CAD potential. Since the precipitation is going to be moderate to heavy for at least 6 hours for most of the Baltimore/Metro area, if it can stay all snow through Wednesday afternoon, I wouldn't be surprised to see widespread 6-8" of accumulation and as much as 10" close the PA line. Everything would have to come together but I don't think it's out of the question at this point. I would imagine most mets are taking the conservative approach right now. Link to comment Share on other sites More sharing options...
Deck Pic Posted February 18, 2019 Share Posted February 18, 2019 12z GFS - We're flirting with mix at 1 pm, but still look pretty good at 4 pm, depending on 900mb-950mb...I guess rates will matter as usual... DCA 1 pm 4 pm Link to comment Share on other sites More sharing options...
nj2va Posted February 18, 2019 Share Posted February 18, 2019 1 minute ago, Deck Pic said: 12z GFS - We're flirting with mix at 1 pm, but still look pretty good at 4 pm, depending on 900mb-950mb...I guess rates will matter as usual... DCA 1 pm 4 pm Thanks for posting. I could see the afternoon fluctuate between all snow, all sleet, and a mix depending on rates. Will truly be a nowcast thing on Wednesday to see where the heaviest bands set up (wild guess...leesburg to FDK etc). Link to comment Share on other sites More sharing options...
Rhode Islander in Balto Posted February 18, 2019 Share Posted February 18, 2019 Any idea on start time for BWI? My husband is flying in from Florida and arrives just before midnight on Wednesday. Link to comment Share on other sites More sharing options...
North Balti Zen Posted February 18, 2019 Share Posted February 18, 2019 Just now, Rhode Islander in Balto said: Any idea on start time for BWI? My husband is flying in from Florida and arrives just before midnight on Wednesday. I believe that gets him in ahead of start time up this way. Link to comment Share on other sites More sharing options...
ravensrule Posted February 18, 2019 Share Posted February 18, 2019 2 minutes ago, Rhode Islander in Balto said: Any idea on start time for BWI? My husband is flying in from Florida and arrives just before midnight on Wednesday. That’s fine. Start time isn’t until 5-6 am. Link to comment Share on other sites More sharing options...
MN Transplant Posted February 18, 2019 Share Posted February 18, 2019 The Euro is by far the most aggressive in pushing the upper level warmth north. Link to comment Share on other sites More sharing options...
ravensrule Posted February 18, 2019 Share Posted February 18, 2019 Just now, MN Transplant said: The Euro is by far the most aggressive in pushing the upper level warmth north. If the Euro is right there wouldn’t be much snow but sleet and plenty of freezing rain. Let’s hope it’s wrong. Link to comment Share on other sites More sharing options...
DDweatherman Posted February 18, 2019 Share Posted February 18, 2019 Just now, MN Transplant said: The Euro is by far the most aggressive in pushing the upper level warmth north. Personally, based on a blend of the models, the Euro could have some credence, but I'm definitely hedging more a mix, putting N/W of 95 solidly in 3-6/4-6" snow from the thump. Now when it comes to sleet vs zr, there could be more zr as the Euro shows but the snow I'm feeling a blend of things. The ICON and FV3 have been pretty consistent run to run, especially ICON. Link to comment Share on other sites More sharing options...
smokeybandit Posted February 18, 2019 Share Posted February 18, 2019 8 minutes ago, Rhode Islander in Balto said: Any idea on start time for BWI? My husband is flying in from Florida and arrives just before midnight on Wednesday. 4 minutes ago, ravensrule said: That’s fine. Start time isn’t until 5-6 am. Not necessarily. Flight might get in in plenty of time before the storm, but if the plane is to sit there overnight (and that late of a flight it likely will be) airlines may not want to risk having the plane stuck there the next morning, *especially* if it's Southwest. Link to comment Share on other sites More sharing options...
ravensrule Posted February 18, 2019 Share Posted February 18, 2019 Just now, smokeybandit said: Not necessarily. Flight might get in on time, but if the plane is to sit there overnight (and that late of a flight it likely will be) airlines may not want to risk having the plane stuck there the next morning, *especially* if it's Southwest. You are probably correct. Southwest is notorious for that. Link to comment Share on other sites More sharing options...
H2O Posted February 18, 2019 Share Posted February 18, 2019 Let’s keep flight talk in banter please Link to comment Share on other sites More sharing options...
MD Snow Posted February 18, 2019 Share Posted February 18, 2019 7 minutes ago, MN Transplant said: The Euro is by far the most aggressive in pushing the upper level warmth north. Yeah it rains on the cities for 10hrs. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted February 18, 2019 Share Posted February 18, 2019 Love the icier look on the guidance. Hope we jackpot ZR...its so fascinating to track and it's very rare in these parts. Link to comment Share on other sites More sharing options...
Inthepines Posted February 18, 2019 Share Posted February 18, 2019 Just now, MD Snow said: Yeah it rains on the cities for 10hrs. A lot of that is sleet Link to comment Share on other sites More sharing options...
yoda Posted February 18, 2019 Share Posted February 18, 2019 FWIW, Charles county in MD just got added to the WSW Link to comment Share on other sites More sharing options...
NorthArlington101 Posted February 18, 2019 Share Posted February 18, 2019 Someone wanted this. Have to know who to ask. Link to comment Share on other sites More sharing options...
mappy Posted February 18, 2019 Share Posted February 18, 2019 snow maps don't really matter much in this setup.... look at precip totals and know that your area probably flips from all snow to sleet to rain during the event. plus... ukie. Link to comment Share on other sites More sharing options...
MD Snow Posted February 18, 2019 Share Posted February 18, 2019 25 minutes ago, Inthepines said: A lot of that is sleet Yeah, maybe so. I'm going off the maps from weather.us. https://weather.us/model-charts/euro/maryland/significant-weather/20190220-2300z.html Link to comment Share on other sites More sharing options...
WEATHER53 Posted February 18, 2019 Share Posted February 18, 2019 Need the high further west. That will be the key Link to comment Share on other sites More sharing options...
dtk Posted February 18, 2019 Share Posted February 18, 2019 3 hours ago, WxUSAF said: I thought they were essentially abandoned years ago. I think the NAM has a planned sunset as well? @dtk? To this and the other question regarding next steps for HiRes guidance... 1) NAM (including nests) are frozen. They will be replaced in the coming years. 2) SREF is also frozen (and now coarse resolution). Effort is being re-oriented toward true high resolution ensembles. 3) HRRR will include ensembles in the DA in 2020, but we cannot afford a true HRRR-ensemble. The HREF fills some of this void in the interim. 4) All of the above are going to be part of some sort of FV3-based, (truly) high resolution convection allowing ensemble. We are still several years away as there is still science to explore for defining the configuration. There's also serious lack of HPC for a large-domain, convection allowing ensemble. Link to comment Share on other sites More sharing options...
MillvilleWx Posted February 18, 2019 Share Posted February 18, 2019 At work, but I wanted to provide a general synopsis and first call type of post with the this system. **ALL FIGURES BELOW** The system will be prime for distributing a large swath of high QPF into a region situated within a strong CAD regime thanks to a robust surface ridge located over the NE US. A fairly prolific jet streak is currently positioned over the NE US and tailing back into the center of the country, which will play a significant role in the lift provided over the southern US and Mid Atlantic (Fig 1). By Wednesday, the jet core will be located to our north with a ridge extension over the SE US displacing the jet to the north, but maintaining or even strengthening the max as we approach mid week (Fig 2). The combination of a surface reflection to the west and the stout ridge in the eastern US will work in tandem to pump the low and mid level southerly flow from the Gulf, initiating a significant moisture transport East of the Mississippi. PWAT's are currently running at seasonal averages, but by Wednesday morning 12z, we will be peaking into the 90th percentile according to forecasted PWAT's of (0.75-0.80) and correlating into local observed climatology out of IAD (Fig 3). The combination of cold low levels and the WAA pattern will induce strong low and mid level frontogenesis that will provide the much needed forcing to generate banding structures and sufficient growth within the DGZ. Given the moist airmass being advected into the area, there will be very little virga to contend with as precip should start quickly and pick up in intensity as the frontgen will coincide with the initial warm push overhead (Fig 4). Within the prime banding structures, snowfall rates of 1-2"/hr will be common and areas within multiple banding structures and a very deep, fully saturated profile will be able to cash in on the greatest snow totals across the sub-forum. The best areas imo will be the areas west of the fall line out to the I-81 corridor and possibly a little west of there with an added orographic element. Our areas along Parrs Ridge from Montgomery Co up to Carroll will also see a benefit of added topographic enhancement with pulse banding added to the equation with the initial frontogen, so there might be dual maxes located within the region coinciding with one area getting the benefit of the greatest moisture advection (Highest QPF max during the snow stage) and the second being the best dual forcing with topography (Elevated areas north of I-70 and out to I-81). This would place eastern WV and the Panhandle along 81 and to the east along the MD line and adjacent So PA into the max potential for snowfall for my forecast. The steady WAA pattern will continue and mid levels above 850mb will begin to rise above freezing from southwest to northeast, providing a steady changeover in precip type from all snow to snow/sleet mix. to eventually all sleet by the afternoon. Model guidance continues to adjust in time with the depth of the CAD wedge, and to TBH, we will not know which model has the best handle on the thermal environment until the storm actually starts. Typically, WAA setups like this will tend to overperform in the warm nose department, transitioning snow to sleet faster than modeled around this time. HOWEVER, this is not a slam dunk, and snow could very well stick around longer than progged on some models (IE the Euro), and more snow may be seen across the area prior to the inevitable flip. I like a general 2-4" totals along I-95 with 1-4" along the eastern side of the bay out to a latitude of Cambridge. A general incremental increase to 3-6" around the fall line is a good first call for that area with 4-8" and local to 10" along the MD line and west of US 15. Local maxima along Parrs Ridge is possible given the expected banding, so within that window between the fall line and US 15, 4-8" is certainly possible in areas above 600'. Sleet will continue through late afternoon before a transition to freezing rain from south to north as the thermal profile sees enough of a warm nose to dispel any further ice pellet formation and maintenance within the lowest portion of the profile. Surface temperatures will struggle to make it beyond freezing for areas north of I-66 and down to Front Royal along I-81 as weak low pressure will develop Wednesday afternoon along the Delmarva due to a tight baroclinic ribbon along the eastern seaboard, allowing surface winds to become light/calm, and low level inversion to hang on and block the southerly winds from mixing efficiently to the surface. Freezing rain accretion will be a question mark as marginal temperatures near freezing with heavier precip do not promote ice development due to latent heat release, but anyone within light precip could encounter up to 0.10-0.25" of ZR pending the longevity of any rain after sleet, and the surface temperatures in question. Best freezing rain setup will likely occur further west of the fall line with US 15 on west the greatest probability of seeing significant icing concerns along with the snow from earlier. This doesn't mean that areas to the east couldn't see a significant impact with freezing rain, and I might be a little conservative on that aspect of the forecast. This will 100% be an impactful storm to basically anyone in the sub-forum that lives west of the Bay! The most significant impacts will be felt in the usual climo areas with pockets of bad conditions felt outside the usual bubble. All it would take for a great impact is a slightly cooler system, greater precip rates to sustain a cooler profile, or a combo of both to really up the ante. I will try to have a more concrete forecast with regional totals by tomorrow evening. Should be a very good storm for many. Figure 1 Figure 2 Figure 3 Figure 4 Link to comment Share on other sites More sharing options...
Bazooka Joe Posted February 18, 2019 Share Posted February 18, 2019 The 12z GFS/FV3 has the snow arriving earlier and lasting longer than the other models, not changing over to sleet or freezing rain until around 3:00 p.m. The EURO is the fastest to bring in the warmer air aloft. If the GFS ultimately is the winner, the Baltimore/Metro could easily see 6-8" of snow. Link to comment Share on other sites More sharing options...
87storms Posted February 18, 2019 Share Posted February 18, 2019 tremendous moisture plume on the nam. Link to comment Share on other sites More sharing options...
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