skierinvermont Posted April 21, 2011 Share Posted April 21, 2011 through april 20 bos: .7 nyc: .3 dca: 1.7 guess through the 28th bos: +1.6 nyc: +1.6 dca: +2.9 and then maybe knock them down to 1.3/1.3/2.5 by the end of the month.. toasty april Link to comment Share on other sites More sharing options...
nzucker Posted April 21, 2011 Share Posted April 21, 2011 through april 20 bos: .7 nyc: .3 dca: 1.7 and then maybe knock them down to 1.3/1.3/2.5 by the end of the month.. toasty april My personal guess is that the next few days come in cooler than expected with upper 40s/low 50s for NYC Friday and Saturday. Not really a toasty April though, only if you play by the numbers. Since I personally know there were a lot of midnight highs and seabreeze days, it's not the type of month I would judge "by the numbers." Been a chilly April in this guy's perspective for sure...also, I stayed quite a bit cooler than Central Park a couple days as the WF/gradient set up just south of here. I wish NWS would convert average temperatures to meaning "the average of each hour of the day's temperature" rather than "high+low/2," which is a notoriously inaccurate measurement. We had several days this month where the temperature got up to 58 or so before the sea breeze came in, so it was literally one hour at 58F and the rest of the afternoon at 50F. That's a day that I consider chilly because most of the time is spent below normal, but NWS marks it down as normal. Link to comment Share on other sites More sharing options...
uncle W Posted April 21, 2011 Share Posted April 21, 2011 My personal guess is that the next few days come in cooler than expected with upper 40s/low 50s for NYC Friday and Saturday. Not really a toasty April though, only if you play by the numbers. Since I personally know there were a lot of midnight highs and seabreeze days, it's not the type of month I would judge "by the numbers." Been a chilly April in this guy's perspective for sure...also, I stayed quite a bit cooler than Central Park a couple days as the WF/gradient set up just south of here. I wish NWS would convert average temperatures to meaning "the average of each hour of the day's temperature" rather than "high+low/2," which is a notoriously inaccurate measurement. We had several days this month where the temperature got up to 58 or so before the sea breeze came in, so it was literally one hour at 58F and the rest of the afternoon at 50F. That's a day that I consider chilly because most of the time is spent below normal, but NWS marks it down as normal. there are times when the low temperature is at midnight and could be significantly lower than the morning minimum...This April seems to be having cooler than normal afternoon temperatures if there is such a stat...If there are hourly records available for every day I'd be interested to see what the normals would be... Link to comment Share on other sites More sharing options...
weatherMA Posted April 21, 2011 Share Posted April 21, 2011 My personal guess is that the next few days come in cooler than expected with upper 40s/low 50s for NYC Friday and Saturday. Not really a toasty April though, only if you play by the numbers. Since I personally know there were a lot of midnight highs and seabreeze days, it's not the type of month I would judge "by the numbers." Been a chilly April in this guy's perspective for sure...also, I stayed quite a bit cooler than Central Park a couple days as the WF/gradient set up just south of here. I wish NWS would convert average temperatures to meaning "the average of each hour of the day's temperature" rather than "high+low/2," which is a notoriously inaccurate measurement. We had several days this month where the temperature got up to 58 or so before the sea breeze came in, so it was literally one hour at 58F and the rest of the afternoon at 50F. That's a day that I consider chilly because most of the time is spent below normal, but NWS marks it down as normal. Well, its all relative. Say Bostons high is reached at 1pm of 64F then knocked back to 52F an hour later due to a sea breeze and the high is recorded as 64F anyway, that's still above normal, relative to average, because days like that were contributed to the average. I agree the +1 is a bit deceiving, but I don't think its been chilly for April. There's been plenty of days 60F+ as well as days 40-50F and rain. IMO its felt like an average April and growing season and trees blooming wise its been about average. Link to comment Share on other sites More sharing options...
skierinvermont Posted April 21, 2011 Share Posted April 21, 2011 My personal guess is that the next few days come in cooler than expected with upper 40s/low 50s for NYC Friday and Saturday. Not really a toasty April though, only if you play by the numbers. Since I personally know there were a lot of midnight highs and seabreeze days, it's not the type of month I would judge "by the numbers." Been a chilly April in this guy's perspective for sure...also, I stayed quite a bit cooler than Central Park a couple days as the WF/gradient set up just south of here. I wish NWS would convert average temperatures to meaning "the average of each hour of the day's temperature" rather than "high+low/2," which is a notoriously inaccurate measurement. We had several days this month where the temperature got up to 58 or so before the sea breeze came in, so it was literally one hour at 58F and the rest of the afternoon at 50F. That's a day that I consider chilly because most of the time is spent below normal, but NWS marks it down as normal. I think you'll find it makes very little difference whether you use hourly obs or high/low as to judging this April's temperatures. In fact, I think it might even bump up the anomaly in NYC a couple tenths using an hourly method. It's quite common for afternoon highs to only last an hour. The primary reason for this months +.3 anomaly thus far is that there has been no extreme cold (notice no frosts near NYC) and there was one moderate warm spell with a +13 day. So it's been primarily right around average, with a brief warm spell. The lack of any real cold is the primary reason for the slightly above average reading so far. Your observation is correct that thus far it has not been a toasty April coming in at only +.3 so far. However, I think the last ten days of the month will be solidly above average and pump that up to >+1. Link to comment Share on other sites More sharing options...
skierinvermont Posted April 21, 2011 Share Posted April 21, 2011 Well, its all relative. Say Bostons high is reached at 1pm of 64F then knocked back to 52F an hour later due to a sea breeze and the high is recorded as 64F anyway, that's still above normal, relative to average, because days like that were contributed to the average. I agree the +1 is a bit deceiving, but I don't think its been chilly for April. There's been plenty of days 60F+ as well as days 40-50F and rain. IMO its felt like an average April and growing season and trees blooming wise its been about average. I agree.. I do not have the perception that it has been a chilly April either. There have been a half dozen+ days I have been outside working in a T-shirt by 10 or 11am. Link to comment Share on other sites More sharing options...
uncle W Posted April 21, 2011 Share Posted April 21, 2011 you can use the monthly max and min and get close to the actual monthly average sometimes...Last month NYC saw a max of 77 and a min of 20...that averages out to 48.5...Monthly average was 42.3...January max min was 53/6...That averages 29.5...The monthly average was 29.7...Last July the range was 103/61...82 average...The monthly average was 81.3... Link to comment Share on other sites More sharing options...
nzucker Posted April 22, 2011 Share Posted April 22, 2011 Well, its all relative. Say Bostons high is reached at 1pm of 64F then knocked back to 52F an hour later due to a sea breeze and the high is recorded as 64F anyway, that's still above normal, relative to average, because days like that were contributed to the average. I agree the +1 is a bit deceiving, but I don't think its been chilly for April. There's been plenty of days 60F+ as well as days 40-50F and rain. IMO its felt like an average April and growing season and trees blooming wise its been about average. I don't think it's been a really cold April, either, obviously. A really cold April means ORH has snowpack till April 10th and NYC metro sees a snow event...we certainly didn't have those things this year. This is just a chilly at times but seasonable month. All the trees and plants seem to be about normal here, with the forsythia and magnolias peaking in April's third week and leaf-out on maples/beeches ready to occur in the final days of the month. I think you'll find it makes very little difference whether you use hourly obs or high/low as to judging this April's temperatures. In fact, I think it might even bump up the anomaly in NYC a couple tenths using an hourly method. It's quite common for afternoon highs to only last an hour. The primary reason for this months +.3 anomaly thus far is that there has been no extreme cold (notice no frosts near NYC) and there was one moderate warm spell with a +13 day. So it's been primarily right around average, with a brief warm spell. The lack of any real cold is the primary reason for the slightly above average reading so far. Your observation is correct that thus far it has not been a toasty April coming in at only +.3 so far. However, I think the last ten days of the month will be solidly above average and pump that up to >+1. It's not uncommon for afternoon highs to last only a short while, but this April the gap between the "NWS high" and the temperature during the majority of the afternoon seems to be high. This is one way in which daily NWS normals can be deceiving in terms of what the climate regime's impact is on sensible weather and vegetation/ecology: it's easy for most of the day's temperature to be controlled by the sea breeze but to have a decently mild high temperature before the change in wind direction takes place...sure the 64F you got to contributes to the feeling outside and growing season, but should that number be used to essentially fill in all the other colder values of the afternoon? Anyway, agree that next week looks mild...the GFS and ECM bring in a troughier pattern in the long-range but that looks not to take hold until May. Link to comment Share on other sites More sharing options...
skierinvermont Posted April 22, 2011 Share Posted April 22, 2011 It's not uncommon for afternoon highs to last only a short while, but this April the gap between the "NWS high" and the temperature during the majority of the afternoon seems to be high. Sorry I don't share this perception.. I look at daily climate histories all the time and I haven't noticed afternoon highs being any more short-lived than normal this month. Even if it were true, I highly doubt it would make much of a difference to the anomaly. It's quite common for afternoon highs to be short-lived. Look at 4/19 for example.. all 24hrs of the day were spent within 5F of the afternoon high. So even though the afternoon high was a good 8 degrees below average, most of the day was actually at or above average. The day went in as a -4 in the official books, but if you were using hourly averages, it probably would have gone in as a +1. These things tend to follow normal distributions and balance out in the end. It is extremely hard to get a large bias in one direction over a 30 day period. 4/20 is another less extreme example where hourly averages would yield a warmer anomaly than the high/low system. Officially it went in as 45/65 +1. But if we look at the hourly obs, we find that after reaching an afternoon high of 65F, temps never fell below 57F for the rest of the day, which is of course quite abnormally warm for a day with a high of 65F. Most April days with a high of 65F I'd expect to be down to 55 by 7 or 8 and 50 by midnight. Instead it was still around 60F at midnight, a mere 5F off the afternoon's high. 4/19 is a really extreme example though where most of the day was above average and yet it goes into the record books as -4F when it should have been +1. 4/20 went in as +1 but probably should have been +3 using hourly obs. Link to comment Share on other sites More sharing options...
nzucker Posted April 22, 2011 Share Posted April 22, 2011 Sorry I don't share this perception.. I look at daily climate histories all the time and I haven't noticed afternoon highs being any more short-lived than normal this month. Even if it were true, I highly doubt it would make much of a difference to the anomaly. It's quite common for afternoon highs to be short-lived. Yea but usually when you get a high of 88F in the summer, for example, it's in the mid-upper 80s for a while during the afternoon. This spring it seems like we just can't keep the seabreeze and clouds out to hold the temperature. Also, freeze warning here tonight, pretty late for Dobbs Ferry. I'm not sure we're going to get there given we're still at 44/29, but it's possible I guess. Ironic that the warmer springs seem to come with these late freezes; we're going to get one well past the 50% date in an April which has generally seen very few cold nights, and the last frost in 2010 wasn't until May 10th for most locations in Westchester, which is well outside the 10% 32F date...weird for the warmest spring on record! Link to comment Share on other sites More sharing options...
weatherMA Posted April 22, 2011 Share Posted April 22, 2011 Sorry I don't share this perception.. I look at daily climate histories all the time and I haven't noticed afternoon highs being any more short-lived than normal this month. Even if it were true, I highly doubt it would make much of a difference to the anomaly. It's quite common for afternoon highs to be short-lived. Exactly. The high lasts for a very short time on the average day. I think this is part of the reason that the public in general thinks its in the 70s when its say in the 60s at noon. They see a 72F on the news cast so they think "hey its going to be in the 70s today", when in reality those "70s" last from 2-5pm during peak heating, and its in the 50s/60s for most of the day untill those late afternoon hours. But that's just my perception. Link to comment Share on other sites More sharing options...
nzucker Posted April 22, 2011 Share Posted April 22, 2011 Most April days with a high of 65F I'd expect to be down to 55 by 7 or 8 and 50 by midnight. Instead it was still around 60F at midnight, a mere 5F off the afternoon's high. This is Central Park you're talking about...it'd take an Ice Age for them to radiate 15 degrees in an afternoon/evening. Again not disagreeing with your ideas but just saying that most people perceive this as a cold April since we've had a lot of afternoon sea breezes, cloudy conditions, and rain. Also saying that the impact of some of the high temps on vegetation development hasn't been great since they have been curtailed by sea breeze. Link to comment Share on other sites More sharing options...
skierinvermont Posted April 22, 2011 Share Posted April 22, 2011 This is Central Park you're talking about...it'd take an Ice Age for them to radiate 15 degrees in an afternoon/evening. Again not disagreeing with your ideas but just saying that most people perceive this as a cold April since we've had a lot of afternoon sea breezes, cloudy conditions, and rain. Also saying that the impact of some of the high temps on vegetation development hasn't been great since they have been curtailed by sea breeze. NYC on average radiates 17 degrees from high to low in April. I might have been slightly off but a high of 65F would normally translate to about 55-56 by 8pm and 51 by midnight. Instead they were sitting pretty at 60F. That's a huge difference and would cause the day to come in much warmer using hourly normals. And 4/19 is an even more extreme case where most of the day was near or above average but the day was booked as -4 using the high/low. Well I don't know who most people is but I and most people I've heard don't agree. Link to comment Share on other sites More sharing options...
nzucker Posted April 22, 2011 Share Posted April 22, 2011 Well I don't know who most people is but I and most people I've heard don't agree. NYC on average radiates 17 degrees from high to low in April. I might have been slightly off but a high of 65F would normally translate to about 55-56 by 8pm and 51 by midnight. Instead they were sitting pretty at 60F. That's a huge difference and would cause the day to come in much warmer using hourly normals. And 4/19 is an even more extreme case. Most people around here have been talking about this "awful cold spring"...it was on the Yankee game the other night, my parents have been discussing it, the online gardening forums are full of comments about "the most wintry spring in years" from Upstate NY to Upper Midwest, most of the NYC forum has been complaints about the cool/rainy weather etc. Certainly a strong contrast from the last two years in any case! Link to comment Share on other sites More sharing options...
skierinvermont Posted April 22, 2011 Share Posted April 22, 2011 Most people around here have been talking about this "awful cold spring"...it was on the Yankee game the other night, my parents have been discussing it, the online gardening forums are full of comments about "the most wintry spring in years" from Upstate NY to Upper Midwest, most of the NYC forum has been complaints about the cool/rainy weather etc. Certainly a strong contrast from the last two years in any case! 2000-2010 averaged +1.8F in April in NYC relative to the 1971-2000 base. Even excluding 2009 and 2010 which were close to +4, the 2000-2008 period was +1.3F in April in NYC. Recent Aprils are probably altering the perception of normal. +.3F is positively freezing these days. I would probably guess that using an hourly system would actually bump up NYC's anomaly of +.3 so far by a couple tenths. Link to comment Share on other sites More sharing options...
BethesdaWX Posted April 22, 2011 Share Posted April 22, 2011 Most people around here have been talking about this "awful cold spring"...it was on the Yankee game the other night, my parents have been discussing it, the online gardening forums are full of comments about "the most wintry spring in years" from Upstate NY to Upper Midwest, most of the NYC forum has been complaints about the cool/rainy weather etc. Certainly a strong contrast from the last two years in any case! Well you have it worse than me, but still getting into the 30's tonight with a dump of rain on the way. This spring has been terrible. I'm just hoping we don't get another summer like 2009, which featured some of the "coldest" July readings in a long time. Link to comment Share on other sites More sharing options...
nzucker Posted April 22, 2011 Share Posted April 22, 2011 2000-2010 averaged +1.8F in April in NYC relative to the 1971-2000 base. Even excluding 2009 and 2010 the 2000-2008 period was +1.3F in April in NYC. Recent April's are probably altering the perception of normal. Yes, and for the whole country as well. April has tended to be a warmer month than May relative to the long-term averages in the past decade. Link to comment Share on other sites More sharing options...
skierinvermont Posted April 22, 2011 Share Posted April 22, 2011 Actually using 2001-2010 (ie excluding 2000) the past 10 Aprils come in even higher close to +2.2 it looks like. Link to comment Share on other sites More sharing options...
BethesdaWX Posted April 22, 2011 Share Posted April 22, 2011 Actually using 2001-2010 (ie excluding 2000) the past 10 Aprils come in even higher close to +2.2 it looks like. Last april had to be a Megatorch, do you have that #? I remember reaching 94 degrees in April 2010, and 92 in MAR 2010. Link to comment Share on other sites More sharing options...
skierinvermont Posted April 22, 2011 Share Posted April 22, 2011 Last april had to be a Megatorch, do you have that #? I remember reaching 94 degrees in April 2010, and 92 in MAR 2010. +5.4 NYC Link to comment Share on other sites More sharing options...
nzucker Posted April 22, 2011 Share Posted April 22, 2011 +5.4 NYC DCA was +4.7F for April 2010 and +3.7F for May 2010. NYC had its earliest 90-degree reading ever on April 7, 2010. Central Park hit 92F that day. Link to comment Share on other sites More sharing options...
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