WxUSAF Posted October 28, 2011 Share Posted October 28, 2011 based on my QPF maps, 1.25-1.5 for all of DC/Balt metro Hmmm...seems lower based on Wunderground maps. Only 2 3-hr panels with most of the area in >0.25" precip. 00z had 3 or 4 panels with that much. What was 00z? Link to comment Share on other sites More sharing options...
yoda Posted October 28, 2011 Share Posted October 28, 2011 15z SREFs not as bullish with QPF... looks like easily 1"+, but the 2" contour from the 09z SREFs is gone (besides a very tiny 2 in S PA) It looks like it still takes the h5 low south of us through RIC then just SE of us I believe Link to comment Share on other sites More sharing options...
WxUSAF Posted October 28, 2011 Share Posted October 28, 2011 Although we're getting into the short-range where ensemble forecasting becomes less reliable, the 12z GFS ensembles mean is colder than the Op. 850 0C line seems right on I-95 at hr 24 and 30 for many members. Link to comment Share on other sites More sharing options...
yoda Posted October 28, 2011 Share Posted October 28, 2011 Nam has initialized... If it holds serve in regards to its 12z run, what would you think Matt? Outlier? Link to comment Share on other sites More sharing options...
TUweathermanDD Posted October 28, 2011 Share Posted October 28, 2011 Although we're getting into the short-range where ensemble forecasting becomes less reliable, the 12z GFS ensembles mean is colder than the Op. 850 0C line seems right on I-95 at hr 24 and 30 for many members. Agree, interesting stuff here. http://raleighwx.americanwx.com/models/gfsensemble/members/12zsnowf048.html overdone of course but much better than the OP, maybe she'll get a little colder at 18z. Link to comment Share on other sites More sharing options...
MN Transplant Posted October 28, 2011 Share Posted October 28, 2011 Warm nose still at 750, but certainly still colder than the other models. Link to comment Share on other sites More sharing options...
Wonderdog Posted October 28, 2011 Share Posted October 28, 2011 Low is a smidge east at hour 18. Link to comment Share on other sites More sharing options...
WxUSAF Posted October 28, 2011 Share Posted October 28, 2011 A tick warmer than 12z through 18hr. Vort max hanging back as well. Link to comment Share on other sites More sharing options...
mitchnick Posted October 28, 2011 Share Posted October 28, 2011 Low is a smidge east at hour 18. that 850 low "looks" like it wants to collapse after 18 hrs, but it didn't done what we've needed it to due at 12z Link to comment Share on other sites More sharing options...
yoda Posted October 28, 2011 Share Posted October 28, 2011 850 line at 18 slices SW-NE on 18z NAM through DC or just west Link to comment Share on other sites More sharing options...
yoda Posted October 28, 2011 Share Posted October 28, 2011 that 850 low "looks" like it wants to collapse after 18 hrs, but it didn't done what we've needed it to due at 12z It does at 21... its in extreme S MD http://mag.ncep.noaa.gov/GemPakTier/MagGemPakImages/nam/20111028/18/nam_namer_021_850_temp_ht.gif Link to comment Share on other sites More sharing options...
mappy Posted October 28, 2011 Share Posted October 28, 2011 850 line at 18 slices SW-NE on 18z NAM through DC or just west And looks to stay there at 21hr... a little more precip then it was from 12z Link to comment Share on other sites More sharing options...
MN Transplant Posted October 28, 2011 Share Posted October 28, 2011 A tick warmer than 12z through 18hr. Vort max hanging back as well. Yeah, unbelievably borderline in DC. From here to Delaware is the 850 track Link to comment Share on other sites More sharing options...
mitchnick Posted October 28, 2011 Share Posted October 28, 2011 here's the sim radar at 21 hours we used to be under the yellows in prior runs that were snowy for us this is telling http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller?prevPage=Param&MainPage=indexℑ=&page=Param&cycle=10%2F28%2F2011+18UTC&rname=SFC-LAYER+PARMS&pname=sim_radar&pdesc=&model=NAM&area=NAMER&cat=MODEL+GUIDANCE&fcast=021&areaDesc=North+America+-+US+Canada+and+northern+Mexico&prevArea=NAMER&currKey=model&returnToModel=&imageSize=L Link to comment Share on other sites More sharing options...
eurojosh Posted October 28, 2011 Share Posted October 28, 2011 No... Through 24 hrs manages to shift the 850 0c to the NW... fringes DC and Baltimore... game GFS? Link to comment Share on other sites More sharing options...
psuhoffman Posted October 28, 2011 Share Posted October 28, 2011 The 850 line runs right through the heart of Baltimore and DC at 18z....then presumably crashes, but only about .15" of precip after 18z.....my best guess is the 850mb low passes just to the southeast of DC but much closer than we want it....my best guess on the euro is you want to be further west than Marcus/Psu Hoffman....I think the Catoctins/Hagerstown/MRB are in good shape for accumulating snows This is splitting hairs but the Euro taken exactly as is, actually is very good for my exact location. Soundings for Westminster MD show 850s stay well below 0 and surface temps about 33-34 the entire event with 1.41 liquid and that is 7 miles south of me and 250 feet lower in elevation. Probably implies 8-10" of very heavy wet snow. Not my prediction. Link to comment Share on other sites More sharing options...
yoda Posted October 28, 2011 Share Posted October 28, 2011 No... Through 24 hrs manages to shift the 850 0c to the NW... fringes DC and Baltimore... game GFS? Actually its moving SE through DC at 24 and way east at 27 Link to comment Share on other sites More sharing options...
RodneyS Posted October 28, 2011 Share Posted October 28, 2011 guidance was not as good back then and I believe there was much more cold air to work with....it way overperformed, but I think there was snow forecast for all of DC metro "The story begins on the evening of November 10, 1987. A cold high pressure for the time of year was to the north of the D.C. area, while a weak 'upper air disturbance' was forecasted to pass to the south of D.C .overnight which would include the D.C. area in the northern fringe of its limited precipitation shield. The term 'upper air disturbance' was years later confirmed by a University of Maryland climatologist to me as being what I had suspected all along: that the meteorologists don’t know what it actually is and that it is 'up in the air' and is indeed a disturbance since it is producing cloudiness or precipitation, hence the term upper air disturbance. The local National Weather Service (NWS) as well as every local news meteorologist including Bob Ryan of channel 4, Sue Palka of channel 5, and Gordon Barnes of channel 9 predicted flurries for the area that night. The fact that the local news meteorologists went with the NWS is of no surprise because they rarely deviated from the others and actually stated what they were thinking, if anything." See http://localnews.col...erans-day-storm Link to comment Share on other sites More sharing options...
mitchnick Posted October 28, 2011 Share Posted October 28, 2011 No... Through 24 hrs manages to shift the 850 0c to the NW... fringes DC and Baltimore... game GFS? NAM's been moving west and GFS was the first model to bring it west, so yep, GFS, as of now, looks to score the coup Link to comment Share on other sites More sharing options...
usedtobe Posted October 28, 2011 Share Posted October 28, 2011 Warm nose still at 750, but certainly still colder than the other models. Looks like we might see a period of sleet or sleet mixed with rain prior to any changeover. As you say, it's still a colder run than the other models. Places like frederick would do well. Link to comment Share on other sites More sharing options...
Wonderdog Posted October 28, 2011 Share Posted October 28, 2011 Really hugging the coast. Link to comment Share on other sites More sharing options...
AlYourWxPal Posted October 28, 2011 Share Posted October 28, 2011 Looks like we might see a period of sleet or sleet mixed with rain prior to any changeover. As you say, it's still a colder run than the other models. Places like frederick would do well. Haha Wes, moving from Charles County to Hagerstown helped me out this time! Link to comment Share on other sites More sharing options...
usedtobe Posted October 28, 2011 Share Posted October 28, 2011 "The story begins on the evening of November 10, 1987. A cold high pressure for the time of year was to the north of the D.C. area, while a weak 'upper air disturbance' was forecasted to pass to the south of D.C .overnight which would include the D.C. area in the northern fringe of its limited precipitation shield. The term 'upper air disturbance' was years later confirmed by a University of Maryland climatologist to me as being what I had suspected all along: that the meteorologists don’t know what it actually is and that it is 'up in the air' and is indeed a disturbance since it is producing cloudiness or precipitation, hence the term upper air disturbance. The local National Weather Service (NWS) as well as every local news meteorologist including Bob Ryan of channel 4, Sue Palka of channel 5, and Gordon Barnes of channel 9 predicted flurries for the area that night. The fact that the local news meteorologists went with the NWS is of no surprise because they rarely deviated from the others and actually stated what they were thinking, if anything." See http://localnews.col...erans-day-storm Actually, Brain Korty of HPC put a forecast for 2-4 inches out prior to the event but none of the local forecasters bought because it was based on then brand new NGM. They were relying more on the LFM and old AVN. Link to comment Share on other sites More sharing options...
MN Transplant Posted October 28, 2011 Share Posted October 28, 2011 No... Through 24 hrs manages to shift the 850 0c to the NW... fringes DC and Baltimore... game GFS? Actually its moving SE through DC at 24 It kinks and surges northward at 20 hours (14z), with the warmest at 16z, and then is cooling by 18z. It probably is snow by 18/19z in DC. Link to comment Share on other sites More sharing options...
MD Snow Posted October 28, 2011 Share Posted October 28, 2011 Looks like DC might get dry slotted with the heaviest of precip to the west in hrs 24-27 Link to comment Share on other sites More sharing options...
usedtobe Posted October 28, 2011 Share Posted October 28, 2011 Haha Wes, moving from Charles County to Hagerstown helped me out this time! It certainly should unless you lose power and end up with no water or heat. Link to comment Share on other sites More sharing options...
yoda Posted October 28, 2011 Share Posted October 28, 2011 It kinks and surges northward at 20 hours (14z), with the warmest at 16z, and then is cooling by 18z. It probably is snow by 18/19z in DC. Thats what I saw... and snow continues for about 3-5 hrs after. Link to comment Share on other sites More sharing options...
TUweathermanDD Posted October 28, 2011 Share Posted October 28, 2011 need someone to check soundings for hrs 27-30, maybe close for a changeover and some snow for DC/BAL. Link to comment Share on other sites More sharing options...
MN Transplant Posted October 28, 2011 Share Posted October 28, 2011 Customary clown map Link to comment Share on other sites More sharing options...
Wonderdog Posted October 28, 2011 Share Posted October 28, 2011 NAM's been moving west and GFS was the first model to bring it west, so yep, GFS, as of now, looks to score the coup So you don't think the NAM basically held its serve from the 12z run? Link to comment Share on other sites More sharing options...
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