tcutter Posted March 29, 2011 Share Posted March 29, 2011 I'd say N&W of 202 at this point looks golden. Between 202 and I-295 (i.e. the I-95 corrdidor) remain in question. Verbatim, the GFS is the only model showing accumulating snow, simply becuase surface temps are too warm on other models. The column is definitely cold enough but remember, it's not January anymore. My guess is rain-->heavy snow with poor ratios, a few inches in Philly and major accumulations in higher elevations (typically above 401') hasn't the euro been a couple of degrees too warm this winter........i thought i remembered that from earlier when we were tracking lots of storms??? Link to comment Share on other sites More sharing options...
NaoPos Posted March 29, 2011 Share Posted March 29, 2011 hasn't the euro been a couple of degrees too warm this winter........i thought i remembered that from earlier when we were tracking lots of storms??? Someone posted an image earlier. It was running bout 1 degree F too warm. As far as surface temps, the bigger issue is the thickness level. As the ccb /deform develops, precipitation rates are intense enough to cool the Column dramatically. So verbatim, the euro is snow Link to comment Share on other sites More sharing options...
DJ Amenzo Posted March 29, 2011 Share Posted March 29, 2011 Everyone need not forget that most if not ALL of this event occurs in late evening and nighttime! Its definitely cold enough for all snow even into the Pine Barrens, imo. I was initially skeptical, but I'm nearly 100% sold now that a historic April snowfall is imminent. I would not be shocked to see 10-15" in PHL metro. Especially with the a) extreme ccb with deform near perfect 500mb vortcity maxima passage c) its April so the suns radiation from the daytime will only act to destabilize the atmosphere, even at night d) the SLP and 850mb low track is perfect right along the BM and concurrent greatest area of baroclinicity. One final thing is that the water in both the DE Bay and the ATL has not warmed much if at all since Feb. This is NOT impossible, it has happened before! Link to comment Share on other sites More sharing options...
Thunder Road Posted March 29, 2011 Share Posted March 29, 2011 hasn't the euro been a couple of degrees too warm this winter........i thought i remembered that from earlier when we were tracking lots of storms??? Yeah amp19psu posted an image that it's been running about 1F too warm lately, so not really enough to invalidate its data. Right now I'm not worried so much about what the models say verbatim, but the fact that it IS April and that surface warmth will be an issue. Watch for models to under-forecast the effect of the late-season sun angle. Link to comment Share on other sites More sharing options...
NaoPos Posted March 29, 2011 Share Posted March 29, 2011 Yeah amp19psu posted an image that it's been running about 1F too warm lately, so not really enough to invalidate its data. Right now I'm not worried so much about what the models say verbatim, but the fact that it IS April and that surface warmth will be an issue. Watch for models to under-forecast the effect of the late-season sun angle. Surface warmth has actual been Kept in check the last few days. Highs in the low 40's and lows @ or around freezing is a lot better than highs in the 50's or even a few days in the 60's. While still a concern bc of the solar radiation, we're not as bad off as we normally could have been( strictly going by pAst climo) Link to comment Share on other sites More sharing options...
Thunder Road Posted March 29, 2011 Share Posted March 29, 2011 Surface warmth has actual been Kept in check the last few days. Highs in the low 40's and lows @ or around freezing is a lot better than highs in the 50's or even a few days in the 60's. While still a concern bc of the solar radiation, we're not as bad off as we normally could have been( strictly going by pAst climo) Yeah I mean we still got a sleetfest in 2007 the day after it was like 72° or something. I'm just saying that this is a wildcard that, imo, should lower confidence. Not saying it can't or won't stick, just that for now the late-season aspect should lower confidence. Link to comment Share on other sites More sharing options...
Thunder Road Posted March 29, 2011 Share Posted March 29, 2011 ECM precip map gives NYC-TTN-DYL-ABE-Pottsville-Scranton and north 1"+ QPF as snow. The rest of us are in that .1"-1" Algreek posted the map in the NYC forum Edit: but it's been deleted already Link to comment Share on other sites More sharing options...
hazwoper Posted March 29, 2011 Share Posted March 29, 2011 Yeah amp19psu posted an image that it's been running about 1F too warm lately, so not really enough to invalidate its data. Right now I'm not worried so much about what the models say verbatim, but the fact that it IS April and that surface warmth will be an issue. Watch for models to under-forecast the effect of the late-season sun angle. Post like yours make me laugh. You do realize that with intense rates being depicted currently on nearly every model and precip occuring for the most part in the over night hours makes your "sun angle" argument nearly moot especially with the temps we are having this week. Just look at what a week 1000mb low on April 9th 1996 did in eastern NJ. Link to comment Share on other sites More sharing options...
Thunder Road Posted March 29, 2011 Share Posted March 29, 2011 Post like yours make me laugh. You do realize that with intense rates being depicted currently on nearly every model and precip occuring for the most part in the over night hours makes your "sun angle" argument nearly moot especially with the temps we are having this week. Just look at what a week 1000mb low on April 9th 1996 did in eastern NJ. Sorry, when I said to watch for it, I meant in the sense that it's a possibility and should not be ruled out, not in the sense that I guarantee the models will bust or anything like that. Link to comment Share on other sites More sharing options...
Yes_Probably_Maybe_No Posted March 29, 2011 Share Posted March 29, 2011 Post like yours make me laugh. You do realize that with intense rates being depicted currently on nearly every model and precip occuring for the most part in the over night hours makes your "sun angle" argument nearly moot especially with the temps we are having this week. Just look at what a week 1000mb low on April 9th 1996 did in eastern NJ. Take another look at that date. This type of stuff doesn't happen often for a reason and thus many are skeptical. Call it sun angle, low probability, whatever...until I see 6" of snow on my driveway, I'm fully prepared to see a cold rain as I think most are (at least around the immediate PHL area). Link to comment Share on other sites More sharing options...
NaoPos Posted March 29, 2011 Share Posted March 29, 2011 Take another look at that date. This type of stuff doesn't happen often for a reason and thus many are skeptical. Call it sun angle, low probability, whatever...until I see 6" of snow on my driveway, I'm fully prepared to see a cold rain, as I think most are (at least around the immediate PHL area). What has 2 thumbs and is expecting snow in Philly? THIS GUY!! On a serious note, the deeper the sytstem, the better chance we have. We got a slushy coating on cars last week in Philly with marginal surface Temps. Yes, I know, diff set up. But it's possible. Especially with a monster storm. Time will tell though. Link to comment Share on other sites More sharing options...
ptb127 Posted March 29, 2011 Share Posted March 29, 2011 Looks like a pretty big snowstorm threat for Friday, huh? Link to comment Share on other sites More sharing options...
hazwoper Posted March 29, 2011 Share Posted March 29, 2011 Take another look at that date. ???? From Rays archive: http://www.njfreeways.com/weather/1996/09-Apr-96.html Link to comment Share on other sites More sharing options...
Yes_Probably_Maybe_No Posted March 29, 2011 Share Posted March 29, 2011 ???? From Rays archive: http://www.njfreeway.../09-Apr-96.html i didn't mean it like that, it was more of a "you're showing me a storm from 15 years ago" type of comment Link to comment Share on other sites More sharing options...
hazwoper Posted March 29, 2011 Share Posted March 29, 2011 i didn't mean it like that, it was more of a "you're showing me a storm from 15 years ago" type of comment Gotcha Last time SEPA/NJ saw 3-6" in April was April 7, 2003 Link to comment Share on other sites More sharing options...
famartin Posted March 29, 2011 Share Posted March 29, 2011 Post like yours make me laugh. You do realize that with intense rates being depicted currently on nearly every model and precip occuring for the most part in the over night hours makes your "sun angle" argument nearly moot especially with the temps we are having this week. Just look at what a week 1000mb low on April 9th 1996 did in eastern NJ. Apparently the models did pretty badly with where the big snows were gonna be during that event. Most forecasts leading up to it had the heavy accumulations in NW NJ and NE PA, but instead those areas got totally ripped off. The CCB sat over SE NJ instead. I was on the edge and had ratios of below 5:1. Link to comment Share on other sites More sharing options...
famartin Posted March 29, 2011 Share Posted March 29, 2011 Gotcha Last time SEPA/NJ saw 3-6" in April was April 7, 2003 As I recall, that event was not well forecast until maybe the 24 hours before. Maybe less. Link to comment Share on other sites More sharing options...
hazwoper Posted March 29, 2011 Share Posted March 29, 2011 Apparently the models did pretty badly with where the big snows were gonna be during that event. Most forecasts leading up to it had the heavy accumulations in NW NJ and NE PA, but instead those areas got totally ripped off. The CCB sat over SE NJ instead. I was on the edge and had ratios of below 5:1. Thanks Ray! Love your site BTW Just goes to show you that with the right set up (and as currently depicted on many models that set up may just occur in SEPA) 6" snowfall is possible in April. In fact, looking at the surface obs on your site from that event, many of the places seeing snow were in the mid 30s during the height of the event. Link to comment Share on other sites More sharing options...
NortheastPAWx Posted March 29, 2011 Share Posted March 29, 2011 atownwxwatcher -- What did the EURO have for NEPA? Link to comment Share on other sites More sharing options...
famartin Posted March 29, 2011 Share Posted March 29, 2011 In the theme of "badly forecast April snow", the April Fool's Day 1997 event was only supposed to be a coating to a couple inches. Instead a widespread swath of central and southern NJ had 6+. Areas in Chester County had over a foot where only a few inches was expected. April 9th 2000, IIRC, was another bust. Anyway, bottom line is we can *hope* the models will have a good idea of what's actually gonna happen 24 hours out. April snows are extra finicky because they're typically thread-the-needle events. Link to comment Share on other sites More sharing options...
JCT777 Posted March 29, 2011 Share Posted March 29, 2011 i didn't mean it like that, it was more of a "you're showing me a storm from 15 years ago" type of comment There was an April 10 storm in 2000 or 2001 (3" of snow for the NW suburbs of Philly), and of course April 7, 2003 which left 4"+ snow and fell mostly during the day. So yes, it's fairly unusual to get 3"+ accumulating snow in the area...but it's possible. And don't forget the March 31 - April 1 storm of 1997 which left 6"+ of snow over most of Bucks and Montgomery counties. Link to comment Share on other sites More sharing options...
atownwxwatcher Posted March 29, 2011 Share Posted March 29, 2011 atownwxwatcher -- What did the EURO have for NEPA? AVP THU 00Z 31-MAR 4.2 -2.9 1015 72 90 0.01 551 538 THU 06Z 31-MAR 0.9 -3.8 1014 98 95 0.06 547 536 THU 12Z 31-MAR 0.8 -3.3 1013 96 72 0.04 546 535 THU 18Z 31-MAR 4.3 -2.9 1011 76 49 0.02 546 537 FRI 00Z 01-APR 2.5 -1.9 1009 91 54 0.02 544 537 FRI 06Z 01-APR 1.2 -1.0 1004 98 89 0.04 540 537 FRI 12Z 01-APR 0.6 -1.7 999 97 90 0.33 535 535 FRI 18Z 01-APR 2.2 -3.7 996 83 95 0.52 530 533 SAT 00Z 02-APR 1.1 -3.0 996 81 86 0.09 530 533 Link to comment Share on other sites More sharing options...
Allsnow Posted March 29, 2011 Share Posted March 29, 2011 mt holly COME THURSDAY NIGHT AND EARLY FRIDAY ALL BETS ARE THEN OFF AS THE LOW IS FORECAST TO INTENSIFY FAIRLY RAPIDLY. THE GFS THERMAL FIELD IS COLDER THAN THE UKMET OR CAN GGEM (HI RES ECMWF NOT VIEWABLE IN TIME). BUT TO A CERTAIN EXTENT, IT DEPENDS UPON WHERE THE DEFORMATION BAND ESTABLISHES ITSELF AS DYNAMIC COOLING WOULD CHANGE THE RAIN TO SNOW REGARDLESS OF LOCATION. PAY ONE NOW OR PAY ONE LATER, WE SUPPOSE IF THE LOW WOULD TREND FARTHER TO THE WEST, THIS WOULD INCREASE THE HYDRO CONCERNS PARTICULARLY IN NJ AS EVENT TOTAL QPF BY THE GFS/CAN GGEM AND UKMET ARE AVERAGING 1.5 TO 2.5 INCHES. THE SYSTEM SHOULD BE EXITING OUR AREA AS FRIDAY CONTINUES AND ONCE THE INTENSITY IS LOST, PRECIPITATION COULD GO BACK TO RAIN. BECAUSE OF MARGINAL TEMPERATURES THIS HAS THE POTENTIAL TO BE A HEAVY WET SNOW EVENT, NOT EXACTLY A UTILITY`S DREAM. WE LOADED IN SOME CONSERVATIVE SNOW AMOUNTS IN THE GRIDS FOR NOW, BUT THIS SHOULD BE VIEWED AS A VERY FIRST GUESS WITH REVISIONS TO FOLLOW. BROUGHT MIN TEMPS CLOSER TO FREEZING FASTER OVERNIGHT BECAUSE OF ANTICIPATED MIXING OR CHANGEOVER AND WITH SNOW PROBABLE ON THE GROUND IN PARTS OF OUR CWA, WENT BELOW MEX MOS FOR MAX TEMPS Link to comment Share on other sites More sharing options...
hazwoper Posted March 29, 2011 Share Posted March 29, 2011 don't look now, but NAM still looks fairly benign with nothing really showing up with the 2nd system. out to 57 on TD Link to comment Share on other sites More sharing options...
jrodd321 Posted March 29, 2011 Share Posted March 29, 2011 Yep amazing how the NAM is all alone with absolutely nothing. Link to comment Share on other sites More sharing options...
Thunder Road Posted March 29, 2011 Share Posted March 29, 2011 Does anyone know Philadelphia's top 10 biggest snow events in April? I know of 1915, but besides that, how do 1997, 2001 and 2003 rank? Could we be talking records broken? Link to comment Share on other sites More sharing options...
atownwxwatcher Posted March 29, 2011 Share Posted March 29, 2011 12 Z ECM means Link to comment Share on other sites More sharing options...
phlwx Posted March 29, 2011 Share Posted March 29, 2011 Does anyone know Philadelphia's top 10 biggest snow events in April? I know of 1915, but besides that, how do 1997, 2001 and 2003 rank? Could we be talking records broken? Snowiest Aprils on record... 19.4 1915 7.0 1917 6.8 1924 5.1 1916 4.3 1971 4.0 1982 3.1 1898 3.0 1965 2.4 1996 2.4 1990 Link to comment Share on other sites More sharing options...
Thunder Road Posted March 29, 2011 Share Posted March 29, 2011 Snowiest Aprils on record... 19.4 1915 7.0 1917 6.8 1924 5.1 1916 4.3 1971 4.0 1982 3.1 1898 3.0 1965 2.4 1996 2.4 1990 Thanks Tom. Interesting that 1915-1916-1917 are all on there. Link to comment Share on other sites More sharing options...
phlwx Posted March 29, 2011 Share Posted March 29, 2011 Thanks Tom. Interesting that 1915-1916-1917 are all on there. 96 is on there too. Link to comment Share on other sites More sharing options...
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