gymengineer Posted December 21, 2016 Share Posted December 21, 2016 Background: The I-95 Northeast Metropolis cities are defined by KU as DC, Baltimore, Philadelphia, NYC, and Boston. The winter of 1995/1996 marked the start of breaking the biggest all-time records for these cities-- the snow total for the season and the single storm record. In that winter, we also entered into the new regime of ramped up frequency in extreme individual winter storms. 95/96: DC- highest seasonal total ever at DCA. #2 for city records. Baltimore- record seasonal total. Philadelphia- record single storm (Blizzard of 96) and record seasonal total. NYC- record seasonal total. Boston- record seasonal total. With Philadelphia's inflated (hourly melted liquid-to-snow conversion based solely on a temperature ratio chart) 30.7" blizzard total that smashed their single storm record by almost 10", the era of the 25"+ snowstorms was kicked off that season. 02/03: Baltimore- record single storm (PDII- 28.2" if you accept LWX's lumping of all four days together into one event- which it clearly wasn't). Boston- record single storm (PDII- 27.5"- somehow Logan airport/Winthrop, MA, got into the bullseye for the entire metropolitan area; easiest cleanup for a record setting storm until NYC's record in 2006). 05/06- NYC- record single storm (2/06- 26.9" but easy cleanup as this was a 'warm' storm overall) 09/10- DC- record seasonal total. *I believe this was the hardest record broken of all on this list, since this actually happened at DCA, not a friendlier climate site.* Baltimore- record seasonal total. Philadelphia- record seasonal total. 14/15- Boston- record seasonal total (incredible feat to beat 95/96). 15/16- Baltimore- record single storm (29.2" in the blizzard). NYC- record single storm (27.5" blizzard total revised up after the NWS service assessment.) So DC, Baltimore, Philly, and Boston ended up having a subsequent season beat their totals from 95/96. NYC is the one city left to experience an epic season that can beat the 95/96 total. So one major all-time record remains: DC's single storm record is the only major record in the Northeast Metropolis that hasn't been beaten from 1995/1996 onward. Do you all think it's even possible for DCA to surpass 28.0"? What would that snowstorm look like? DC's top three snowstorms feature one moisture bomb (Knickerbocker) and two extreme cold events (Blizzard of 1899 and PDI). The stall in the Knickerbocker storm with the subsequent ENE drift (and therefore sparing New England altogether) has been echoed in various degrees by 1/96, 2-5-6/10, and 1/16. I think 2/5-6/10 came closest to matching 1/22, especially taking into account where the reporting station was in 1/22. If the low elevation spots including DCA had just been 2-3 degrees colder in the first six hours of 2/5-6/10, that would have gotten DCA easily over the 20" mark and maybe even pushed their total towards 24". But DCA still wouldn't have hit 28". Of course, IAD's total (where LWX staff superceded the IAD crew) in that storm was an incredible 32.4". So the best banding plus good enough temps set up just west of I-95 in Howard County and further west in Loudoun County. I have a hard time picturing a marginal temperature, but super-wet, storm as the one getting DCA to 28", though. I think the lowest elevations will continue to underperform the liquid equivalent in that scenario. With the frigid powder bombs like 2/1899 and 2/79, the question is whether those storms linger long enough to push to 28". Neither achieved that benchmark, so it's also hard to picture how that would work too. Maybe a storm like PDII (2/03) with the hours and hours of overrunning but a somewhat better CAD scenario as the coastal starts to form? Get 10" into the bank and then crank out another 19" with a rapidly intensifying coastal low. Or 1/16 without the dry-slot? Sure, some GFS and NAM and other individual runs bulls-eyed DC, but the consensus discussion was that the Blue Ridge areas would still do the best in spite of any single model run. And that's what verified. So, I think it would be difficult for a 1/96 or 1/16 type outcome to hit 28". That's the type of storm with a middle negative "surprise" (mixing, dry slot, etc.). What do you all think as the likeliest scenario to get DCA to 28.1"? Link to comment Share on other sites More sharing options...
ge0 Posted December 21, 2016 Share Posted December 21, 2016 Don't know if it's possible without the nearby suburbs getting 40+. And even if 28.1" fell, would they actually report it? I remember someone mentioning that they reported 17.8" in the Jan '16 storm and then an 18.0" snowpack the day after... Link to comment Share on other sites More sharing options...
PrinceFrederickWx Posted December 21, 2016 Share Posted December 21, 2016 I often wonder what the theoretical max is that we could get from one system (or three days as LWX defines it). Could DCA or BWI ever crack the 30" mark? Could IAD ever reach 40"? I have no idea. Link to comment Share on other sites More sharing options...
Scarlet Pimpernel Posted December 21, 2016 Share Posted December 21, 2016 8 hours ago, gymengineer said: So one major all-time record remains: DC's single storm record is the only major record in the Northeast Metropolis that hasn't been beaten from 1995/1996 onward. Do you all think it's even possible for DCA to surpass 28.0"? What would that snowstorm look like? DC's top three snowstorms feature one moisture bomb (Knickerbocker) and two extreme cold events (Blizzard of 1899 and PDI). The stall in the Knickerbocker storm with the subsequent ENE drift (and therefore sparing New England altogether) has been echoed in various degrees by 1/96, 2-5-6/10, and 1/16. I think 2/5-6/10 came closest to matching 1/22, especially taking into account where the reporting station was in 1/22. If the low elevation spots including DCA had just been 2-3 degrees colder in the first six hours of 2/5-6/10, that would have gotten DCA easily over the 20" mark and maybe even pushed their total towards 24". But DCA still wouldn't have hit 28". Of course, IAD's total (where LWX staff superceded the IAD crew) in that storm was an incredible 32.4". So the best banding plus good enough temps set up just west of I-95 in Howard County and further west in Loudoun County. I have a hard time picturing a marginal temperature, but super-wet, storm as the one getting DCA to 28", though. I think the lowest elevations will continue to underperform the liquid equivalent in that scenario. With the frigid powder bombs like 2/1899 and 2/79, the question is whether those storms linger long enough to push to 28". Neither achieved that benchmark, so it's also hard to picture how that would work too. Maybe a storm like PDII (2/03) with the hours and hours of overrunning but a somewhat better CAD scenario as the coastal starts to form? Get 10" into the bank and then crank out another 19" with a rapidly intensifying coastal low. Or 1/16 without the dry-slot? Sure, some GFS and NAM and other individual runs bulls-eyed DC, but the consensus discussion was that the Blue Ridge areas would still do the best in spite of any single model run. And that's what verified. So, I think it would be difficult for a 1/96 or 1/16 type outcome to hit 28". That's the type of storm with a middle negative "surprise" (mixing, dry slot, etc.). What do you all think as the likeliest scenario to get DCA to 28.1"? I don't know if DCA itself will ever break 28", though areas in the immediate suburban area have come close to that recently (and areas a bit farther out of the immediate metro have exceeded it). Several reports within the District itself were in the 20-25" range during recent big storms. As a start I'd like to see DCA actually crack 20" for the first time ever. Was the Knickerbocker measurement actually officially taken somewhere in Georgetown in DC? The micro-climate and lower elevation of DCA just simply may be difficult to overcome even for large events. I won't get into measurement issues here, but throw that in there as well I guess! As for the likeliest scenario for DCA to break/approach 28"...or even 20"...I think we've seen that in recent years though it didn't happen there. I seriously thought that DCA would get near the Knickerbocker total during Snowmageddon (Feb. 5-6, 2010), and again thought they would during this past January's blizzard (Jan. 22-23, 2016). In both cases, I thought they'd easily get over 20" and be the top storm at the DCA location; especially the January blizzard because that was very cold from the start. Neither storm did of course, and in fact both registered "only" 17.8", interestingly enough. I actually recall reading one of the LWX forecast discussions right as Snowmageddon was upon us (might still have it saved), and they mused over the possibility of topping the Knickerbocker event at that time. Link to comment Share on other sites More sharing options...
MN Transplant Posted December 21, 2016 Share Posted December 21, 2016 January 28, 1772: This storm was named the Washington and Jefferson Snow Storm since both of their diaries recorded it. The storm left 36 inches of snow (3 feet) in central and northern Virginia and the Washington area. Official weather records did not begin until after the Civil War. Therefore, this storm is not listed as the record, but it was the largest snow for this area ever noted. Link to comment Share on other sites More sharing options...
MN Transplant Posted December 21, 2016 Share Posted December 21, 2016 As noted before, the most likely scenario is a more perfect Feb. 2010 with better temps on the front end and perfect snow growth temps aloft. Something that has the stall and pivot. Alternatively, we could just go Biblical and work up a 1993 with an eastern track. Link to comment Share on other sites More sharing options...
gymengineer Posted December 21, 2016 Author Share Posted December 21, 2016 2 hours ago, Always in Zugzwang said: I don't know if DCA itself will ever break 28", though areas in the immediate suburban area have come close to that recently (and areas a bit farther out of the immediate metro have exceeded it). Several reports within the District itself were in the 20-25" range during recent big storms. As a start I'd like to see DCA actually crack 20" for the first time ever. Was the Knickerbocker measurement actually officially taken somewhere in Georgetown in DC? The micro-climate and lower elevation of DCA just simply may be difficult to overcome even for large events. I won't get into measurement issues here, but throw that in there as well I guess! As for the likeliest scenario for DCA to break/approach 28"...or even 20"...I think we've seen that in recent years though it didn't happen there. I seriously thought that DCA would get near the Knickerbocker total during Snowmageddon (Feb. 5-6, 2010), and again thought they would during this past January's blizzard (Jan. 22-23, 2016). In both cases, I thought they'd easily get over 20" and be the top storm at the DCA location; especially the January blizzard because that was very cold from the start. Neither storm did of course, and in fact both registered "only" 17.8", interestingly enough. I actually recall reading one of the LWX forecast discussions right as Snowmageddon was upon us (might still have it saved), and they mused over the possibility of topping the Knickerbocker event at that time. And even with no measuring issues, both 2/5-6/10 and 1/16 just plain fell short of challenging the Knickerbocker storm at DCA, as you alluded to. Both had one phase that the modeling suggested, but maybe not to the extent of what actually happened. Most models ran too cold for the lowest elevations for 2/5-6/10, suggesting significant daytime accumulations whereas areas around DCA and Old Town Alexandria took almost until nightfall before the snow really began to accumulate, costing them a few inches. And while models showed a dry slot verbatim for 1/16, how far west it punched was not forecast well ahead of time. That also goes the larger point--- the super cold storms where there's not even a hint of mixing for DCA have been just a tad too progressive to get anywhere in DC near 30". The ones that stall out like 1/96, 2/5-6/10, and 1/16 have all introduced other wrinkles like mixing/temperature concerns/dry slots during the actual progression of the storm. The Knickerbocker Storm was pretty unique in its track too--- the low center was further east off the coast than 1/96, 2/5-6/10, or 1/16. So the max stripe of precip literally bulls-eyed the I-95 corridor instead of against the Blue Ridge, and we were kept in the 20's for most of the storm. Maybe it's as straight forward as that: We just need a slow moving storm with the Knickerbocker track instead of the more 'classic' track just off of Norfolk. Link to comment Share on other sites More sharing options...
Bob Chill Posted December 21, 2016 Share Posted December 21, 2016 IMO- the hardest thing for DC with a single 24 hour event is that a storm big enough to produce those kinds of precip totals will almost always mix. A two pronged storm like PDII could do it though or a noreaster with a trailing ULL for "round 2" or something like that. Being on the NW side of a perfect track dynamic closed ULL can have some sick totals but they are bullseye style. Link to comment Share on other sites More sharing options...
EastCoast NPZ Posted December 21, 2016 Share Posted December 21, 2016 It is hard to imagine that 28" total is ever reached again in DC proper, especially at Reagan. That is right up there, it seems, with breaking the all-time record low temp. A product of a bygone era, no longer possible in a warming, super-urban environment. Link to comment Share on other sites More sharing options...
gymengineer Posted December 21, 2016 Author Share Posted December 21, 2016 17 minutes ago, EastCoast NPZ said: It is hard to imagine that 28" total is ever reached again in DC proper, especially at Reagan. That is right up there, it seems, with breaking the all-time record low temp. A product of a bygone era, no longer possible in a warming, super-urban environment. Yes on the all-time record low. But when even 95/96 couldn't get it done, most probably assumed the same impossibility for the seasonal snowfall record. Then 09/10 happened. Link to comment Share on other sites More sharing options...
TJ3 Posted December 22, 2016 Share Posted December 22, 2016 8 hours ago, gymengineer said: And even with no measuring issues, both 2/5-6/10 and 1/16 just plain fell short of challenging the Knickerbocker storm at DCA, as you alluded to. Both had one phase that the modeling suggested, but maybe not to the extent of what actually happened. Most models ran too cold for the lowest elevations for 2/5-6/10, suggesting significant daytime accumulations whereas areas around DCA and Old Town Alexandria took almost until nightfall before the snow really began to accumulate, costing them a few inches. And while models showed a dry slot verbatim for 1/16, how far west it punched was not forecast well ahead of time. That also goes the larger point--- the super cold storms where there's not even a hint of mixing for DCA have been just a tad too progressive to get anywhere in DC near 30". The ones that stall out like 1/96, 2/5-6/10, and 1/16 have all introduced other wrinkles like mixing/temperature concerns/dry slots during the actual progression of the storm. The Knickerbocker Storm was pretty unique in its track too--- the low center was further east off the coast than 1/96, 2/5-6/10, or 1/16. So the max stripe of precip literally bulls-eyed the I-95 corridor instead of against the Blue Ridge, and we were kept in the 20's for most of the storm. Maybe it's as straight forward as that: We just need a slow moving storm with the Knickerbocker track instead of the more 'classic' track just off of Norfolk. Didn't PD 1 have a track further of the coast? Is that the kind of track that one would want to see again for such high totals? Link to comment Share on other sites More sharing options...
gymengineer Posted December 22, 2016 Author Share Posted December 22, 2016 50 minutes ago, TJ3 said: Didn't PD 1 have a track further of the coast? Is that the kind of track that one would want to see again for such high totals? PD1 was closer to the coast near our latitude but, yes, it then headed out to sea sparing New England altogether. It maxed out in the 20-25" range in the eastern suburbs, so it was just too fast to have been a contender for all-time highest. That track plus a stall for 6 hours right off the lower Delmarva would have made it an all-time highest contender. Link to comment Share on other sites More sharing options...
Scarlet Pimpernel Posted December 22, 2016 Share Posted December 22, 2016 15 hours ago, gymengineer said: PD1 was closer to the coast near our latitude but, yes, it then headed out to sea sparing New England altogether. It maxed out in the 20-25" range in the eastern suburbs, so it was just too fast to have been a contender for all-time highest. That track plus a stall for 6 hours right off the lower Delmarva would have made it an all-time highest contender. Interesting point...and yes, that storm really only hit the mid-Atlantic before going out to sea. Areas just to the east of DC got the greatest totals as you say. The irony is that even though it might not have been an all-time highest event in most areas, PD-I stands as the largest single storm total at DCA (with just over 18" I believe)! I still think (hope?) that one day, DCA will actually top the 20" mark...as I said above, I honestly thought that Snowmageddon or the January 2016 blizzard would have easily done that, but alas, it was not to be at DCA. Link to comment Share on other sites More sharing options...
PrinceFrederickWx Posted December 22, 2016 Share Posted December 22, 2016 20 hours ago, EastCoast NPZ said: It is hard to imagine that 28" total is ever reached again in DC proper, especially at Reagan. That is right up there, it seems, with breaking the all-time record low temp. A product of a bygone era, no longer possible in a warming, super-urban environment. I disagree- I mean we recently had one of the top five coldest months ever in February 2015, no reason we can't do it for a day. This decade has really been incredible when you think about it- we've broken heat records, cold records, snowfall records... even lowest barometric pressure recorded. Multiple HECS, tropical systems, etc. Link to comment Share on other sites More sharing options...
MN Transplant Posted December 22, 2016 Share Posted December 22, 2016 37 minutes ago, PrinceFrederickWx said: I disagree- I mean we recently had one of the top five coldest months ever in February 2015, no reason we can't do it for a day. This decade has really been incredible when you think about it- we've broken heat records, cold records, snowfall records... even lowest barometric pressure recorded. Multiple HECS, tropical systems, etc. I think it may actually be easier to do it for a month than a day. The DCA problem has so many aspects. First, it requires the river to be completely frozen over. That is generally doable in a situation where we are talking about negative teens. The second part is harder - we need a breeze. DCA just won't radiate like the other sites do in cold, clear, calm conditions. So, you are talking negative teens where you aren't even under the core of the high pressure. A thick, fresh snowcover would help also, and it is just rare that we get a cold outbreak after a big storm. Link to comment Share on other sites More sharing options...
PrinceFrederickWx Posted December 22, 2016 Share Posted December 22, 2016 58 minutes ago, MN Transplant said: I think it may actually be easier to do it for a month than a day. The DCA problem has so many aspects. First, it requires the river to be completely frozen over. That is generally doable in a situation where we are talking about negative teens. The second part is harder - we need a breeze. DCA just won't radiate like the other sites do in cold, clear, calm conditions. So, you are talking negative teens where you aren't even under the core of the high pressure. A thick, fresh snowcover would help also, and it is just rare that we get a cold outbreak after a big storm. I see your point. DCA would also be very hard cause the record from the old site is so low (-15!?). BWI seems more doable with the record "only" at -7, since we were able to hit -5 in the "modern era" (1994). Link to comment Share on other sites More sharing options...
ORH_wxman Posted December 22, 2016 Share Posted December 22, 2016 39 minutes ago, PrinceFrederickWx said: I see your point. DCA would also be very hard cause the record from the old site is so low (-15!?). BWI seems more doable with the record "only" at -7, since we were able to hit -5 in the "modern era" (1994). Jan 1982 was actually when the -5F at DCA was recorded...I think 1994 was -4F. But yeah, those are the coldest temps recorded at the Reagan airport site since it came into existence in 1941. The siting change would almost certainly be too much of an obstacle to overcome even without any backround warming of the climate. Link to comment Share on other sites More sharing options...
EastCoast NPZ Posted December 22, 2016 Share Posted December 22, 2016 4 hours ago, PrinceFrederickWx said: I disagree- I mean we recently had one of the top five coldest months ever in February 2015, no reason we can't do it for a day. This decade has really been incredible when you think about it- we've broken heat records, cold records, snowfall records... even lowest barometric pressure recorded. Multiple HECS, tropical systems, etc. -15F at National is not happening. Ever. Link to comment Share on other sites More sharing options...
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