MN Transplant Posted January 20, 2012 Share Posted January 20, 2012 NAM is about as good as I think we will see with the front end A 4 hr period of snow probably changing to sleet 50-75% of the way through and maybe 0.15-.2" QPF....1/2" to 1" of snow and then some crust on top....epic for this winter Yeah, that is a good read. Maybe three hours of snow, switching over to sleet/zr. Then a fairly long lull with maybe some fr drizzle before the next batch. Link to comment Share on other sites More sharing options...
weathergeek Posted January 20, 2012 Share Posted January 20, 2012 where can us newbies see the sim radar? Link to comment Share on other sites More sharing options...
MN Transplant Posted January 20, 2012 Share Posted January 20, 2012 where can us newbies see the sim radar? http://www.instantweathermaps.com is my preferred spot at the moment twisterdata and NCEP are also fine. twisterdata has forecast soundings. Link to comment Share on other sites More sharing options...
MN Transplant Posted January 20, 2012 Share Posted January 20, 2012 The QPF looks more reasonable You seeing this at 14-15-16z? Maybe stays ZR down into the city. Link to comment Share on other sites More sharing options...
yoda Posted January 20, 2012 Share Posted January 20, 2012 still a formidable ice event NW of DC...someone might even stay snow longer than progged Perhaps even just N and W (aka Loudoun/ W Montgomery)... 12z NAM at 15z SAT had 2m 0c line in MD... 18z still has south of N VA (IAD prob 30/31) Link to comment Share on other sites More sharing options...
yoda Posted January 20, 2012 Share Posted January 20, 2012 You seeing this at 14-15-16z? Maybe stays ZR down into the city. 15z at IAD def frozen... DCA prob frozen transitioning to rain from what I see Link to comment Share on other sites More sharing options...
ThePhotoGuy Posted January 20, 2012 Share Posted January 20, 2012 where can us newbies see the sim radar? Click "Sim Radar" http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller?prevPage=Model&MainPage=indexℑ=&page=Param&cycle=01%2F20%2F2012+18UTC&rname=SFC-LAYER+PARMS&pname=sim_radar&pdesc=&model=NAM&area=NAMER&cat=MODEL+GUIDANCE&fcast=&areaDesc=North+America+-+US+Canada+and+northern+Mexico&prevArea=NAMER&currKey=model&returnToModel=&imageSize=M Link to comment Share on other sites More sharing options...
mitchnick Posted January 20, 2012 Share Posted January 20, 2012 I wonder if NAM is going to have it changing back with that 2nd batch it'll be close I think Link to comment Share on other sites More sharing options...
TUweathermanDD Posted January 20, 2012 Share Posted January 20, 2012 NAM much colder than 12z this run, zr hangs on around BWI down to DC. Nam snow map on Raleigh Baltimore 3-4'' About as wintry as its been on the NAM so far, colder yet again. Link to comment Share on other sites More sharing options...
MN Transplant Posted January 20, 2012 Share Posted January 20, 2012 I wonder if NAM is going to have it changing back with that 2nd batch it'll be close I think Changing back? Link to comment Share on other sites More sharing options...
mitchnick Posted January 20, 2012 Share Posted January 20, 2012 Changing back? to snow at the end GFS hinted at it Link to comment Share on other sites More sharing options...
MN Transplant Posted January 20, 2012 Share Posted January 20, 2012 Have to see the text, but that might be 0.2" to 0.25" of ice for nw burbs just over 3 hours in the morning. Link to comment Share on other sites More sharing options...
MN Transplant Posted January 20, 2012 Share Posted January 20, 2012 to snow at the end GFS hinted at it 850s are +5 at 10am, unless I'm getting what you mean mixed up. Link to comment Share on other sites More sharing options...
yoda Posted January 20, 2012 Share Posted January 20, 2012 I'd probably take off 0.05 to at most 0.1 for rain (21-24 hrs)... but good QPF still Link to comment Share on other sites More sharing options...
TUweathermanDD Posted January 20, 2012 Share Posted January 20, 2012 forget what I said about QPF...Nam is still a cold juicy beast :lol Yes indeed, hey its trying to win us over. Link to comment Share on other sites More sharing options...
stormtracker Posted January 20, 2012 Share Posted January 20, 2012 Not out of the question DC could see up to 2" before changeover IF the Nam is correct. Not sure where this "crippling" meme is coming from as it never looked that way around the city anyway. Near the Mason Dixon line could be another story...but it's survivable. Link to comment Share on other sites More sharing options...
TUweathermanDD Posted January 20, 2012 Share Posted January 20, 2012 Not out of the question DC could see up to 2" before changeover IF the Nam is correct. Not sure where this "crippling" meme is coming from as it never looked that way around the city anyway. Near the Mason Dixon line could be another story...but it's survivable. Nothing historic obviously, nam was pretty wintry this run regardless. Link to comment Share on other sites More sharing options...
mappy Posted January 20, 2012 Share Posted January 20, 2012 Not out of the question DC could see up to 2" before changeover IF the Nam is correct. Not sure where this "crippling" meme is coming from as it never looked that way around the city anyway. Near the Mason Dixon line could be another story...but it's survivable. I'm not expecting to survive this. Link to comment Share on other sites More sharing options...
stormtracker Posted January 20, 2012 Share Posted January 20, 2012 Damn..NAM still has DC sfc at freezing around 15z Link to comment Share on other sites More sharing options...
stormtracker Posted January 20, 2012 Share Posted January 20, 2012 I'm not expecting to survive this. I will be praying for you. Link to comment Share on other sites More sharing options...
usedtobe Posted January 20, 2012 Share Posted January 20, 2012 850s are +5 at 10am, unless I'm getting what you mean mixed up. It's interesting, the temps in the warm layer drop between 10 am and 1 PM. Here's the sounding for IAD off the plymouth site. It's still below freezing at the surface and the max temp in the warm layer is below plus 3 which on average is a sleet sounding. The other interesting thing is the temp on the sounding below does not jive with 2m temp on the plane view on the NCEP site Date: 24 hour Eta valid 18Z SAT 21 JAN 12 Station: KIAD Latitude: 38.95 Longitude: -77.45 ------------------------------------------------------------------------------- LEV PRES HGHT TEMP DEWP RH DD WETB DIR SPD THETA THE-V THE-W THE-E W mb m C C % C C deg knt K K K K g/kg ------------------------------------------------------------------------------- SFC 1003 100 -0.1 -0.9 94 0.9 -0.4 321 7 272.9 273.5 272.6 282.5 3.55 1 1000 121 -0.1 327 7 273.1 2 950 530 -1.5 -1.8 98 0.2 -1.6 336 9 275.6 276.2 274.2 285.3 3.53 3 900 962 2.1 2.0 99 0.2 2.1 313 17 283.7 284.6 280.2 297.4 4.90 4 850 1425 2.8 2.4 97 0.4 2.6 304 14 289.0 290.0 283.1 304.3 5.35 5 800 1916 2.2 1.9 98 0.4 2.1 265 28 293.5 294.5 285.1 309.5 5.48 6 750 2435 -0.1 -0.2 100 0.0 -0.2 262 33 296.4 297.4 285.8 311.3 5.04 7 700 2985 -2.6 -2.9 98 0.3 -2.7 258 32 299.6 300.4 286.4 312.9 4.42 8 650 3571 -5.4 -6.0 96 0.5 -5.7 259 41 302.8 303.5 286.9 314.3 3.77 9 600 4194 -9.1 -10.0 93 0.9 -9.4 254 49 305.6 306.2 287.1 314.9 2.98 10 550 4863 -13.2 -14.4 91 1.2 -13.6 247 51 308.4 308.8 287.3 315.6 2.27 11 500 5582 -18.0 -19.5 88 1.5 -18.4 242 51 311.1 311.4 287.6 316.5 1.64 12 450 6360 -23.8 -25.7 84 1.9 -24.2 239 50 313.3 313.5 287.7 316.9 1.05 13 400 7207 -31.4 -33.9 79 2.5 -31.7 240 52 314.2 314.3 287.5 316.1 0.55 14 350 8135 -39.5 -42.7 71 3.2 -39.7 240 59 315.5 315.6 287.6 316.4 0.25 15 300 9171 -47.6 -51.6 63 4.0 -47.7 241 75 318.3 318.3 288.3 318.7 0.11 16 250 10352 -56.6 238 84 321.9 17 200 11739 -61.3 248 70 335.8 18 150 13534 -59.2 262 67 368.0 19 100 16067 -60.8 257 51 410.3 Link to comment Share on other sites More sharing options...
yoda Posted January 20, 2012 Share Posted January 20, 2012 Damn..NAM still has DC sfc at freezing around 15z Yes... its prob in the middle of transitioning to rain... just north and west of DC proper still FZRA Link to comment Share on other sites More sharing options...
WxUSAF Posted January 20, 2012 Share Posted January 20, 2012 maybe it scores a coup...go NAM! Ahem...if there is ~3" of snow in central MD tomorrow morning, it will be the RGEM that scored the coup Link to comment Share on other sites More sharing options...
mappy Posted January 20, 2012 Share Posted January 20, 2012 I will be praying for you. Thank you for the kind words Link to comment Share on other sites More sharing options...
Ian Posted January 20, 2012 Author Share Posted January 20, 2012 And with that Ian, NAM a bit wetter thru 9 and slightly colder with the 850's. Also, precip shield a few miles south. SREF QPF > NAM QPF at this range probably. Tho I really have not looked at much today as I'm crushed at work. Link to comment Share on other sites More sharing options...
TUweathermanDD Posted January 20, 2012 Share Posted January 20, 2012 Ahem...if there is ~3" of snow in central MD tomorrow morning, it will be the RGEM that scored the coup True true, well there is certainly a chance. Link to comment Share on other sites More sharing options...
yoda Posted January 20, 2012 Share Posted January 20, 2012 FWIW AREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 302 PM EST FRI JAN 20 2012 .SYNOPSIS... -- Changed Discussion -- LOW PRESSURE WILL BRING A WINTRY MIX OF PRECIPITATION TO MID ATLANTIC REGION OVERNIGHT AND SATURDAY...FOLLOWED BY A COLD FRONT SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTH SUNDAY INTO EARLY MONDAY...WITH LOW PRESSURE PASSING TO THE SOUTH. A SECOND COLD FRONT WILL MOVE ACROSS THE REGION MONDAY NIGHT INTO TUESDAY. -- End Changed Discussion -- && .NEAR TERM /THROUGH SATURDAY/... -- Changed Discussion -- COLD FRONT NOW SITUATED ACROSS THE CAROLINAS...WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. OVER THE LAST SEVERAL HOURS...HAVE NOTICED DEWPOINTS ARE SEVERAL DEGREES LOWER THAN MODEL GUIDANCE AND TEMPS HAVE ALSO BEEN SLOWER TO RISE TODAY. RIDGE AXIS WILL SHIFT OFFSHORE EARLY THIS EVENING AS LOW PRESSURE MOVES INTO THE MID ATLANTIC FROM THE TN VALLEY. THE LOW CENTER IS EXPECTED TO PASS OVER THE EXTREME SOUTHERN CWFA OR JUST TO THE SOUTH. MOISTURE WILL BEGIN TO OVERSPREAD THE COLD AND DRY AIRMASS IN PLACE FOR THE REMAINDER OF THE AFTERNOON AND EARLY EVENING HOURS. PRECIP IS EXPECTED TO BREAK OUT IN THE WEST FIRST AND SPREAD TO THE EAST BY THE LATE EVENING. BUFKIT SOUNDINGS DO SHOW A WINTRY MIX OF SNOW...SLEET AND FREEZING RAIN FOR OVERNIGHT AND EARLY SATURDAY ACROSS MUCH OF THE CWFA. SOME RAIN MAY MIX WITH SLEET ACROSS LOWER SOUTHERN MARYLAND. MODELS HAVE COME IN COLDER THE PAST FEW RUNS...SO MORE SLEET/SNOW MAY MIX WITH THE FREEZING RAIN...ESPECIALLY ACROSS THE NW AND ALONG THE MASON DIXON LINE. ONE TO THREE INCHES OF SNOW/SLEET IS POSSIBLE ESPECIALLY ALONG THE MASON DIXON LINE. SNOW/SLEET WILL TRANSITION OVER TO FREEZING RAIN LATE EARLY SATURDAY MORNING. ICE ACCUMULATIONS BETWEEN ONE AND TWO TENTHS OF AN INCH ARE EXPECTED ACROSS THE NORTHERN TWO THIRDS OF THE CWFA...WHILE LESS THAN A TENTH OF AN INCH IS EXPECTED ACROSS THE SOUTHERN THIRD OF THE CWFA. LOCALLY HIGHER AMOUNTS OF ICING ARE POSSIBLE ACROSS NORTHEAST MD...NEAR THE MASON DIXON LINE...AND ACROSS THE FAR WESTERN SUBURBS OF DC. THIS AXIS OF LOCALLY HIGHER ICING (MESOSCALE BANDING) MAY SHIFT WITH LATER MODEL RUNS...SO NOT CONFIDENT ENOUGH TO ISSUE A WARNING AT THIS TIME. FREEZING RAIN EARLY SATURDAY MORNING WILL HANG ON THE LONGEST ACROSS THE NORTHERN QUARTER OF THE CWFA...WHERE COLD AIR IS HARD TO SCOUR OUT. ELSEWHERE...FREEZING RAIN WILL TRANSITION TO ALL RAIN DURING THE MID TO LATE MORNING. PRECIP IS EXPECTED TO HANG ON NEAR THE FRONT THROUGH THE AFTERNOON. -- End Changed Discussion -- Link to comment Share on other sites More sharing options...
WinterWxLuvr Posted January 20, 2012 Share Posted January 20, 2012 SREF QPF > NAM QPF at this range probably. Tho I really have not looked at much today as I'm crushed at work. It's wetter than it was at 9z. Temps at a quick glance seem comparable. Link to comment Share on other sites More sharing options...
mappy Posted January 20, 2012 Share Posted January 20, 2012 High res NAM on e wall has snow starting in DC around 1am Link to comment Share on other sites More sharing options...
Ian Posted January 20, 2012 Author Share Posted January 20, 2012 my benchmark for significant is from a weenie perspective and in the context of DC climo in general and this winter...I don't need to have widespread week long power outages, felled trees on roofs and wires and roads, thousands of minor/major auto accidents and loss of life to enjoy a weather event or judge its impact no one needs the above to make it a decent event. plenty of folks have been taking forecast precip and calling it all ice. this is like a mod event as forecast, maybe mod+ if the "worst case" happens. yeah in this winter its like feb 5-6. Link to comment Share on other sites More sharing options...
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