Boston high temps?
Alex
around 2 or 3PM. However, most other places hit highs around 5 or 6
PM. When I was in Denver it would get the hottest right around 5:30 or
so. Can anyone explain why we have early hi temps in Boston?
Alex
CRAIG265
you put denver in the same league as Florida. Perhaps that is true during the
late summer monsoon season in denver, but not for the rest of the year.
I agree with your seabreeze effect in boston. Unless there is a strong offshore
breeze , the seabreeze kicks during the spring and summer in particular.
Joseph Bar-Tholomai
Probably the sea breeze. Regarding denver, I think their maximums
occur earlier during the afternoon more than you are aware - clouds
& thundershowers are common during afternoon (though sometimes late
or evening).
Joseph
Joseph Bar-Tholomai
> you put denver in the same league as Florida. Perhaps that is true during the
> late summer monsoon season in denver, but not for the rest of the year.
Actually, most thunderstorms occur during July :
http://www.crh.noaa.gov/den/cli/normals.html
Note that the average 21 days with thunderstorms during June & July is 34.4 %
and the 29.3 during June-August is 31.8 %. The upslope effect is quite
prominent during summer, which is (of course) what I was referring to.
During winter, 5-6 PM is around sunset. Perhaps the statistics would prove
me wrong, but I doubt the average maximum temperature during any season at
Denver is past 3-4 PM.
Joseph
Joseph Bar-Tholomai
Even so, the maximum temperature was almost certainly sometime between 3 & 5
PM MDT (21-23 Z) :
KDEN 081953Z 00000KT 10SM FEW110 35/M01 A3009 RMK AO2 SLP091 T03501011=
KDEN 082053Z 00000KT 10SM FEW110 36/M01 A3008 RMK AO2 SLP086 T03561006 56009=
KDEN 082153Z VRB04KT 10SM FEW110 36/M01 A3007 RMK AO2 SLP083 T03561006=
KDEN 082253Z 36010G15KT 10SM FEW110 36/M01 A3006 RMK AO2 SLP082 T03561006=
KDEN 082353Z 04008KT 10SM FEW110 35/M01 A3006 RMK AO2 SLP080 T03501006 10361
20333 56005=
That's for August 8, though the days aren't becoming that much shorter yet.
The way things seem or are at a specific location can (of course) differ.
Joseph
FerroWX17
reached between 3 and 5 PM, execpt when a cold front (or perhaps a warm front)
pass through at the time of day that doesn't make such a readying occur.
FerroWX17
.....that doesn't make suach a *reading* occur.
Joseph Bar-Tholomai
> I always thought that on the average the highest daily temperatures were
> reached between 3 and 5 PM, execpt when a cold front (or perhaps a warm front)
> pass through at the time of day that doesn't make such a readying occur.
People would probably be surprised to find the average much nearer noon
than they think, considering all days. Very seldom does a maximum occur
at midnight of the previous day - much more often at midnight of the
subsequent day. That is because cold fronts are typically much stronger
than warm fronts. Even if warm air advection occurs during the night,
some cooling also does (even under low clouds). If a strong cold front
passes around midnight, quite often the temperature will decrease until
morning & never increase back to the midnight reading - so you get alot
of 0's using the 24-hour scale. Cloudiness also tend to be much more
abundant during PM than AM at most locations during summer.
(Of course) a maximum is more apt to be late day a clear summer day with
warm air advection. I think the original post assumes we are talking
about a generally clear summer day. Even then, I think it is generally
mid-late afternoon.
Joseph
FerroWX17
King Pineapple
between 1 and 3 PM.
Alex <alex...@mediaone.net> wrote in message
news:3990C8BF...@mediaone.net...
> I have noted the Boston usually hits it's high temperature for the day
> around 2 or 3PM. However, most other places hit highs around 5 or 6
> PM. When I was in Denver it would get the hottest right around 5:30 or
> so. Can anyone explain why we have early hi temps in Boston?
>
> Alex
>
>
Mur Wolf
>> around 2 or 3PM. However, most other places hit highs around 5 or 6
>> PM. When I was in Denver it would get the hottest right around 5:30 or
>> so. Can anyone explain why we have early hi temps in Boston?
>>
>> Alex
In the pre-mocroprocessor/digital age, min/max temperature observations for a
station that didn't have 24 hour manned coverage would either:
a) have someone awake at midnight to record the temperatures and reset the
min/max thermometer or
b) assume that the minimum reading as it appeared on the min/max thermometer in
the morning, occured after midnight, which would be true, most, but not all, of
the time.
Was this problem ignored by pre-digital climatologists, or did they redefine
the min/max temperature day to run from 9:00 P.M.to 9:00 P.M.?
Just wondering.
Steve Okonski
> Here's something I've always been curious about.
> In the pre-mocroprocessor/digital age, min/max temperature observations for a
> station that didn't have 24 hour manned coverage would either:
There exist analog (mercury) thermometers that can record max and min
temperatures. They've been around awhile (long before digital thermometers), but I
don't know exactly when they were invented.
pegleg
from what is known as "Time of Observation bias." For example,
when I was a grad student at Nebraska, I spoke with the campus
police, who took campus observations.
They used 5 PM as their observation time, so that there was a
bias on summer afternoons. I got suspicious after finding days
with 105-105 max temps, and in which the second day was much
cooler at regional 1st order stations.
Conversely, the 5 AM time is also biased to be too low.
There is a project at NCDC, heading by Tom Peterson (I believe)
that is trying to gather long-term records from rural stations
with a consistent time of observation, and where the location
(another bias!) has remained the same.
Bob Strauss
What I would really like to see would be someone integrate the
area under the temperature curve and compare month to month
values from that.
-----------------------------------------------------------
Got questions? Get answers over the phone at Keen.com.
Up to 100 minutes free!
http://www.keen.com
Mur Wolf
>There exist analog (mercury) thermometers that can record max and min
>temperatures. They've been around awhile (long before digital thermometers),
but I
>don't know exactly when they were invented.
Thanks for the response. I guess I wasn't clear in my posting. I know that
there are analog min/max thermometers. I own a couple! My confusion
has to do with how the person who retires for the night at, say, 10:00 P.M.,
and gets up, at, say, 7:00 A.M., can tell whether the min/max readings on
an analog thermometer occured before or after midnight. In other words, when
this person records his minimum temperature observations at 7:00 A.M., does
he attribute the minimum reading to "today's date" or "yesterday's date"?
I hope that clarifies the question.
wxcentral
close to the water...if not right on the water. I've noticed the same
relationships here in NJ/E PA...places like Atlantic City and Wildwood
will often have their highs between 1-4 pm...on days when there isn't a
significant land breeze, of course...whereas places like Philadelphia
and Wilmington will not hit them until 5-6pm.
Brian
Sent via Deja.com http://www.deja.com/
Before you buy.
Joseph Bar-Tholomai
> My confusion has to do with how the person who retires for the night at,
> say, 10:00 P.M., and gets up, at, say, 7:00 A.M., can tell whether the
> min/max readings on an analog thermometer occured before or after midnight.
Sometimes being a good observer involves being a good forecaster. Though
I've only been keeping records a relatively brief year & 5 months :
http://www.enter.net/~jbartlo/mtpdat.htm
I make the commitment to be there at midnight whenever necessary. For many
situations, you can clearly reset the thermometer during early night or even
sometimes evening because you are almost certain the daily maximum/minimum
won't occur before midnight and that the temperature will decrease between
midnight and sunrise will be lower (though that can sometimes be surprising
- even though I've been observing for only that long, I've forecast to some
extent for 17 years, so I wasn't fooled yet to my knowledge regarding that).
> In other words, when this person records his minimum temperature
> observations at 7:00 A.M., does he attribute the minimum reading to
> "today's date" or "yesterday's date"? I hope that clarifies the question.
Nowhere is it carved in stone that the observation must be taken at midnight.
Though this almost certainly best, any consistent 24-hour period is a daily
value. When I was a student at University of Michigan (undergrad & grad),
observations from the North Campus site were taken at 5 PM every day, along
with a max/min for the 24-hour period. The observer (Dennis Kahlbaum) also
took reading during most mornings & attempted to estimate a 24 hour midninght-
midnight min/max. His observations were good, yet took a very long time
before the state climatologist accepted them - probably for 3 primary reasons :
The 5 PM observation time, close proximity of the instruments to the Space
Research Building, and because the office was at Michigan State University ;)
This issue is actually most relevant regarding precipitation. Even daily
values from standard observing stations are not strictly midnight-midnight,
but as typically 5-15 minutes before midnight. This can make a much
greater difference than for temperature - for a rare situation, all
precipitation for one day attributed to another.
Joseph
Mur Wolf
>This issue is actually most relevant regarding precipitation. Even daily
>values from standard observing stations are not strictly midnight-midnight,
>but as typically 5-15 minutes before midnight. This can make a much
>greater difference than for temperature - for a rare situation, all
>precipitation for one day attributed to another.
>
>Joseph
Joseph,
I hadn't even considered the precipitation issue.
I guess I'm just one of those people who believes in holding those who report
weather information to a high standard.
I have no tolerance for the media "temperature extrapolators" - it's 20 degF
in Worcester and it's 28 degF in Boston, so let's broadcast that Framingham,
halfway between the Boston and Worcester, is 24 degF. Or even more aggravating
are the radio stations that rattle off a list of local town temperatures
which you know are made up. Temperatureure extrapolation and plain old making
up of temperatures are worse than "surmising" that the minimum temp occured
after midnight. But, when it comes to news or weather,
I'll take no information over bogus information any day!
Thanks again for the response.
Joseph Bar-Tholomai
> I hadn't even considered the precipitation issue.
> I guess I'm just one of those people who believes in holding those who report
> weather information to a high standard.
This high standard generally does exist. The can set their clocks to the
UNSO master clock
and issue the reports at exactly midnight (or maybe say they do & actually
report at a random time as much as a few minutes different to confuse the
enemy ;) ), but the practical reason why hourly observations are slightly
before the hour is so they can be available at the hour. These days this
is not so much of a problem - during the old days, that 5-15 minutes was
often needed.
> I have no tolerance for the media "temperature extrapolators" - it's 20 degF
> in Worcester and it's 28 degF in Boston, so let's broadcast that Framingham,
> halfway between the Boston and Worcester, is 24 degF.
Even more significant is probably that airports are generally unrepresentative
of the surrounding regions. They tend to have a greater diurnal range -
particularly than rural and wooded areas. Most people are aware of urban
effects also. I stick my thermometer under a bush (just kidding), so although
my location is about 325 feet lower than MPO 2 miles away, their maximum
temperatures are typically 2-3° higher during a sunny summer day.
> Or even more aggravating are the radio stations that rattle off a list of
> local town temperatures which you know are made up.
I'd believe about 60 % of what I hear on radio stations if I listened.
> Thanks again for the response.
You're welcome.
Joseph
Rodney Barney
temperature measurements up here in Canada, and the
standard climatological day runs from 06Z to 06Z.
That means that out west in British Columbia it runs
from 10PM to 10PM local standard time, while here in
the east (Newfoundland) it runs from 2:30 AM to 2:30 AM.
Make that one hour later when on daylight savings time.
This time was arbitrarily chosen because it is in the
middle of the night across the country. It is good for
comparing temperatures in neigbouring locations that
happen to be in different time zones on days when
an abnormal temperature trend occurs.
This practice only applies to hourly reporting stations.
The climat stations, which are run by volunteers who
record the weather daily, and send in their forms at
the end of the month, record the minimum registered
between 8PM and 8AM, and the maximum between 8AM to 8PM,
local time.
Rodney
--
http://www.easternwebworks.com/straitside/weather.html
Striars
for example if it reached 85 degrees at 3 pm cooled off and then reached 85 at
5 pm, what time would the official high be recorded 3 or 5? Same question for
low temps. Thanks.
Alex
can be an ocean thing. There is no wind shift noted. I take OBS and
the hi temp on sunny days occurs between 2-3PM, unless there is a front
of something. There is no wind shift at my house, but it still hits the
high at this time. I live 6 miles WNW of Boston in Cambridge.
Alex
Joseph Bar-Tholomai
As I mentioned in another response, this could vary with specific location
for several reasons. I note that BOS's maximum corresponded with yours
yesterday, but was between 3 & 5 today, with no sea breeze.
Joseph