WEATHER53 Posted March 14, 2014 Share Posted March 14, 2014 I truely believe that the official Washington records from the 1800's thru 1945 are Completely Irrelevant. Apples and oranges comparing to current times. Even the 40's, 50's, 60, and 70's are sketchy due to the surrounding of the airport by commercial development of a swamp which used to lie immediately to the sw-w-nw of DCA. To me, the coldest day in mid March is back in 1993. Link to comment Share on other sites More sharing options...
olafminesaw Posted March 14, 2014 Share Posted March 14, 2014 The 15z SREF is a huge hit FWIW from what I can tell. 10"+, long duration. Link to comment Share on other sites More sharing options...
mitchnick Posted March 14, 2014 Share Posted March 14, 2014 The 15z SREF is a huge hit FWIW from what I can tell. 10"+, long duration. definitely colder than last run Link to comment Share on other sites More sharing options...
high risk Posted March 14, 2014 Share Posted March 14, 2014 The SPC 09z SREF plumes (waiting for 15z, but I expect little change) are interesting. In a nutshell, 11 members have 4.5" or more (with a few into the crazy range), and 10 are basically nothing. But if you break it down by member, the 7 NMB members, which are initialized off of the NAM, are all members with little snow. This is likely due to whatever the NAM is analyzing at the start to cause the 500 wave to close off feeding into these members, and they all amplify like crazy and have either rain or zr/ip. If you believe that the closed 500 low idea is wrong and toss those NMB members, you would end up with a mean that's even higher than the healthy 6" obtained with the non-snowy NMB members. The ratios in the SREF may be too generous, but all of the members are really wet. Only one member (suppressed) was under 0.75" of liquid for DC. Link to comment Share on other sites More sharing options...
Huffwx Posted March 14, 2014 Share Posted March 14, 2014 Last year with good cold aloft.. we had immediate stick age on palm Sunday. Roads were more slush till the really heavy stuff, but it's not just surface.. temp was at 32. Was .7 or so an hour for 3 hours before skies opened up. Link to comment Share on other sites More sharing options...
yoda Posted March 14, 2014 Share Posted March 14, 2014 definitely colder than last run Def colder at the 850 level... -4c 850 line is down in our area 0c 2m line crosses through DCA ~11pm on 15z SREFs -- I believe it was at 4am or so on the 09z SREFs Link to comment Share on other sites More sharing options...
ecosense Posted March 14, 2014 Share Posted March 14, 2014 As far as stickage last night my backyard had 18" of snowpack and the front had 6". I think if we get snow Monday it will all stick in my yard. Disclaimer is that I am on a north facing 25% slope. The models are looking like a good thump Sunday night probably rules out fieldwork on Monday. Link to comment Share on other sites More sharing options...
Random Chaos Posted March 14, 2014 Share Posted March 14, 2014 In a nutshell, 11 members have 4.5" or more (with a few into the crazy range), and 10 are basically nothing. If you look at the 3-hrly temperatures on the SREF plume, a few of those 0-total members have absolutely unbelievable temperatures (two are even in the upper 50's all night long and into Monday)! Link to comment Share on other sites More sharing options...
Scraff Posted March 14, 2014 Share Posted March 14, 2014 Some very solid analysis for anyone that wants to check it out. Again, Rayno is no non-sense / hype and one of AccuWX best mets. http://www.accuweather.com/en/weather-video/snowstorm-midwest-mid-atlanti/2430839568001?channel=top_story Link to comment Share on other sites More sharing options...
yoda Posted March 14, 2014 Share Posted March 14, 2014 Afternoon LWX AFD .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...HIGHEST IMPACT TIME OF THE LOW PRESSURE SYSTEM WILL BE SUNDAYNIGHT INTO THE MORNING MORNING COMMUTE. MODELS HAVE COME INTOBETTER AGREEMENT TODAY WITH THE GFS AND ECMWF TRENDING COLDER ANDA TAD FURTHER SOUTH WITH THE TRACK OF THE LOW WHICH WOULD BEFAVORABLE FOR ACCUMULATING SNOWFALL ESPECIALLY FROM ABOUT 03ZTHROUGH 12Z MONDAY AS TEMPERATURES FALL INTO THE 20S FOR MOSTAREAS. BOUNDARY LAYER TEMPS MAY HOLD IN A BIT WARMER OVER SOUTHERNPORTIONS OF THE FORECAST AREA...ESPECIALLY SOUTHERN MD WHEREMIXING WITH RAIN AND SLEET MAY BE POSSIBLE BEFORE THE CHANGEOVEROCCURS. MORNING RUNS OF THE SREF AND NAM CONTINUE TO SHOW MOREP-TYPE CONCERNS EAST OF THE BLUE RIDGE BUT GIVEN COLD HIGHPRESSURE LOCKED TO THE NORTH AND WINDS BACKING AROUND TO THENORTH...TOUGH TO SEE HOW BL TEMPS STAY ABOVE FREEZING AS LONG ASTHEY HAVE SHOWN. HIGHEST CONFIDENCE FOR MODERATE TO PERHAPSSIGNIFICANT SNOWFALL IS NORTH AND WEST OF I-95/METRO AREAS...MORESO NORTH ALONG I-81 AS PRECIP SHOULD BE MOSTLY SNOW FOR THE ENTIREEVENT. A BIT CONCERNED WITH THE CONTINUED SOUTHWARD SHIFT AND APRECIP GRADIENT DEVELOPING AS OCCURRED DURING A SIMILAR EVENT ACOUPLE WEEKS AGO. EITHER WAY...SITUATION IS TRENDING TOWARD A MORESIGNIFICANT EVENT AND WATCHES MAY NEED TO BE CONSIDERED DURING THEOVERNIGHT SHIFT. Link to comment Share on other sites More sharing options...
high risk Posted March 14, 2014 Share Posted March 14, 2014 If you look at the 3-hrly temperatures on the SREF plume, a few of those 0-total members have absolutely unbelievable temperatures (two are even in the upper 50's all night long and into Monday)! yes, those are 2 NMB members which amplify like crazy and therefore pull plenty of warm air north. They each have the rain/non-rain line way up in northern PA. Link to comment Share on other sites More sharing options...
mitchnick Posted March 14, 2014 Share Posted March 14, 2014 If you look at the 3-hrly temperatures on the SREF plume, a few of those 0-total members have absolutely unbelievable temperatures (two are even in the upper 50's all night long and into Monday)! 12Z NAM is more wound up than the CRASS any model that is more wound up than the CRASS is flat out wrong Link to comment Share on other sites More sharing options...
smokeybandit Posted March 14, 2014 Share Posted March 14, 2014 As far as stickage last night my backyard had 18" of snowpack and the front had 6". I think if we get snow Monday it will all stick in my yard. Disclaimer is that I am on a north facing 25% slope. I did the Baltimore to State College, PA, drive up and back this morning. There was basically no snow cover the entire way there except the plowed piles and shaded banks. Link to comment Share on other sites More sharing options...
paulythegun Posted March 14, 2014 Share Posted March 14, 2014 As someone said above, the 15z SREF (like 09z) has a couple of members with unrealistically warm temps Monday. The SREF MEDIAN (more appropriate than the mean) is 10" of snow here....we're now in the point of the model runs where I start drooling over a potential historic late March storm before eventually settling back to the reality that 3-5" would be pretty cool. Link to comment Share on other sites More sharing options...
Deck Pic Posted March 14, 2014 Share Posted March 14, 2014 FWIW, Euro Ens mean, supports the OP...though a bit further south and drier,. Link to comment Share on other sites More sharing options...
midatlanticweather Posted March 14, 2014 Share Posted March 14, 2014 FWIW, Euro Ens mean, supports the OP...though a bit further south and drier,. From what I am seeing, a further shift to the south seems possible.. I am amazed by the shifts south this year. On another note, last system had an insane dry slot.. any hints of this or is that the whole gap in precip thing? Link to comment Share on other sites More sharing options...
SLPressure Posted March 14, 2014 Share Posted March 14, 2014 At what point does one rely more on the Op over the ensembles? I've heard 5 days and 3 days thrown around. Also, what time frame are the SREF's most dependable? Thanks in advance. Link to comment Share on other sites More sharing options...
high risk Posted March 14, 2014 Share Posted March 14, 2014 The parallel NAM, using the background error covariances from the GFS, looks a lot more like the other guidance - less amplified. Compared to the ops NAM, it's slower with the onset of the precip, not as far north, and more snowy in DC (although it's amplified enough to still mix with sleet from DC to the south later Sunday night.) http://www.emc.ncep.noaa.gov/mmb/mmbpll/nampll_namx/ Link to comment Share on other sites More sharing options...
hosj III Posted March 14, 2014 Share Posted March 14, 2014 At what point does one rely more on the Op over the ensembles? I've heard 5 days and 3 days thrown around. Also, what time frame are the SREF's most dependable? Thanks in advance. Probably 3 days. And SREF's are never dependable unless you cut QPF in half and add 2-5 degrees. Link to comment Share on other sites More sharing options...
T. August Posted March 14, 2014 Share Posted March 14, 2014 Probably 3 days. And SREF's are never dependable unless you cut QPF in half and add 2-5 degrees. I thought they run a little on the warmer side? Link to comment Share on other sites More sharing options...
Heisy Posted March 14, 2014 Share Posted March 14, 2014 NAM is going to be a perfect example of what HM is talking about. Energy is still buried, but we a good amount still escapes. This should be a nice run for DC Link to comment Share on other sites More sharing options...
RIC_WX Posted March 14, 2014 Share Posted March 14, 2014 I did the Baltimore to State College, PA, drive up and back this morning. There was basically no snow cover the entire way there except the plowed piles and shaded banks. On the contrary, I did the PA Turnpike Wednesday AM from US 15 to PHL and was amazed how much snowcover lingered along the way (and the tree damage), even as far east as 476. But can only assume a lot of this attritted by Wednesday PM when the cold front arrived. It was near 70* when I left PHL in the afternoon. Link to comment Share on other sites More sharing options...
hosj III Posted March 14, 2014 Share Posted March 14, 2014 I thought they run a little on the warmer side? At the long range, because they tend to amp things up and warm southern places. however, when you get closer to the event and they stop amping it up so much but still spit out too much QPF that is affecting their temps. Link to comment Share on other sites More sharing options...
Heisy Posted March 14, 2014 Share Posted March 14, 2014 Meh it ended up a bit north, but I imagine that area of heavy precip will shift S come 00z...NW bias on display. Link to comment Share on other sites More sharing options...
Deck Pic Posted March 14, 2014 Share Posted March 14, 2014 Meh it ended up a bit north, but I imagine that area of heavy precip will shift S come 00z...NW bias on display. lol...it nails you.... Link to comment Share on other sites More sharing options...
T. August Posted March 14, 2014 Share Posted March 14, 2014 Meh it ended up a bit north, but I imagine that area of heavy precip will shift S come 00z...NW bias on display. From what I'm looking at it looks more south compared to 12z. Maybe I'm wrong... Also, maybe a bit colder? Link to comment Share on other sites More sharing options...
Scarlet Pimpernel Posted March 14, 2014 Share Posted March 14, 2014 From what I'm looking at it looks more south compared to 12z. Maybe I'm wrong... Hard to say, but kinda looks a bit colder at 850-mb than 12Z... ETA: this is through 60-h, running a bit slow here. Link to comment Share on other sites More sharing options...
Ji Posted March 14, 2014 Share Posted March 14, 2014 NAMED but its bs Link to comment Share on other sites More sharing options...
WinterWxLuvr Posted March 14, 2014 Share Posted March 14, 2014 Think I'll just go with the HPC Link to comment Share on other sites More sharing options...
T. August Posted March 14, 2014 Share Posted March 14, 2014 Hard to say, but kinda looks a bit colder at 850-mb than 12Z... You can really tell if you compare the snowfall maps (yeah, I know!) on Instant Weather Maps. the 12z barely got 3" south of the M/D line, but it now has 12" just north of Baltimore. This is all of course based on snow maps lol. Link to comment Share on other sites More sharing options...
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