June 2025 Obs/Disco

[dendrite]

13 minutes ago, powderfreak said:

1 minute.

1:54pm... 95F

1:55pm... 84F

Yeah something is wrong. To pull down a 5min mean from 95F to 84F in 1 minute requires a big number coming off and a low one going on.

[Typhoon Tip]

Jun 25, 1:55 pm	84	70	62	88	ENE	14	10.00	SCT060		29.96	29.98
Jun 25, 1:54 pm	95	68	42	100	ENE	14	10.00	FEW037 BKN065	1015.10	29.96	29.98	95	78
Jun 25, 1:50 pm	93	68	44	98	ENE	14	10.00	SCT050 BKN070		29.96	29.98
Jun 25, 1:45 pm	93	68	44	98	E	14	10.00	SCT050 BKN070		29.96	29.98
Jun 25, 1:43 pm	93	68	44	98	E	15G21	10.00	SCT050 BKN070		29.96	29.98
Jun 25, 1:40 pm	86	68	55	89	E	10	10.00	BKN050 BKN070		29.96	29.98
Jun 25, 1:35 pm	84	68	58	87	E	10	10.00	BKN050 BKN070		29.95	29.97
Jun 25, 1:30 pm	82	68	62	85	E	10	10.00	BKN050 BKN070		29.96	29.98
Jun 25, 1:25 pm	79	66	65		ESE	9	10.00	BKN050 BKN070		29.96	29.98

[CoastalWx]

I would also expect to see a baro change and dewpoint change with such temp fluctuations and I don't see any.

[Damage In Tolland]

23 minutes ago, WxWatcher007 said:

Really? That’s nuts. Not even 2011?

I don’t have any physical records but I don’t recall 3 straight days of 90+ here since 2005. 
Did ORH do it then?

[Damage In Tolland]

8 minutes ago, CoastalWx said:

I don't know, but something is off. I can't explain it as a rogue heat plume off the runway. 

Beer?

[dendrite]

4 minutes ago, CoastalWx said:

I would also expect to see a baro change and dewpoint change with such temp fluctuations and I don't see any.

Nothing from the Winthrop CWOP. 

https://www.weather.gov/wrh/timeseries?site=D3706&hours=24

[powderfreak]

8 minutes ago, CoastalWx said:

I would also expect to see a baro change and dewpoint change with such temp fluctuations and I don't see any.

Yeah the dews stand out.  No real change.  If it was mixing out, and 10-15F temp changes in short order, you'd think you'd see at least 5-8 dew changes?

I just think when we saw PBG up here do a 15 degree increase to 100F, the dew plummeted with the temp change.

 

[dendrite]

2 minutes ago, Damage In Tolland said:

I don’t have any physical records but I don’t recall 3 straight days of 90+ here since 2005. 
Did ORH do it then?

There's no way this is your first heat wave there. None. I've had like 10 of them here.

[CoastalWx]

1 minute ago, dendrite said:

Nothing from the Winthrop CWOP. 

https://www.weather.gov/wrh/timeseries?site=D3706&hours=24

 

1 minute ago, powderfreak said:

Yeah the dews stand out.  No real change.  If it was mixing out, and 10-15F temp changes in short order, you'd think you'd see at least 5-8 dew changes?

 

Yeah I would expect to see some change. It's interesting. Usually if they overachieve on temps with a seabreeze it's an ESE wind which IIRC allows more land to be heated before reaching ASOS. But this one is peculiar. 

[CoastalWx]

2 minutes ago, dendrite said:

There's no way this is your first heat wave there. None. I've had like 10 of them here.

Very ACATT of him to say that.

[SouthCoastMA]

Tip learned a lot about swirlies in high school

[bristolri_wx]

4 minutes ago, CoastalWx said:

Very ACATT of him to say that.

WTF does ACATT mean??  TYIA!

[ineedsnow]

Just now, bristolri_wx said:

WTF does ACATT mean??  TYIA!

All cold all the time

[CoastalWx]

Wish I had access to the aircraft reports out of Logan. Curious how shallow sea breeze is.

[bristolri_wx]

7 minutes ago, ineedsnow said:

All cold all the time

Never would have guessed that… even here on this forum. 

[dendrite]

17 minutes ago, CoastalWx said:

 

Yeah I would expect to see some change. It's interesting. Usually if they overachieve on temps with a seabreeze it's an ESE wind which IIRC allows more land to be heated before reaching ASOS. But this one is peculiar. 

Let's assume the real raw temp was 80F. The 1-min obs are 5-min means of the raw 1-min averaged temps. So to drop 11F in a minute it would require a delta of 55F change. So in theory 15F of it is on the 95 to 80 side, but you'd have to be losing an ob of +40F on the other end (135F). 

Am I missing something here?

[dendrite]

However, the 5 min avg never got above 95F (6hr max at 1754z was 95F). And the temp spiked and triggered a SPECI at 1743z when it jumped from 86F to 93F in 3 minutes. So there must have been a few random big spikes thrown in there with normal 80-82F obs unless I have no clue what I'm talking about anymore.

[CoastalWx]

2 minutes ago, dendrite said:

Let's assume the real raw temp was 80F. The 1-min obs are 5-min means of the raw 1-min averaged temps. So to drop 11F in a minute it would require a delta of 55F change. So in theory 15F of it is on the 95 to 80 side, but you'd have to be losing an ob of +40F on the other end (135F). 

Am I missing something here?

WTF. I don't think I realized that. But even so, nobody else around them had that jump. I'm sorry, but downtown BOS is not cooler than Logan on a stout E wind in late June. 

[dendrite]

@OceanStWx Can you get early access to the raw 1-min data?

[TheClimateChanger]

7 minutes ago, dendrite said:

Let's assume the real raw temp was 80F. The 1-min obs are 5-min means of the raw 1-min averaged temps. So to drop 11F in a minute it would require a delta of 55F change. So in theory 15F of it is on the 95 to 80 side, but you'd have to be losing an ob of +40F on the other end (135F). 

Am I missing something here?

IEM says ASOS temperatures are based on 2-minute averages, perhaps that's the discrepancy. If it's two minute averaging, those temperatures jumps are plausible.

Source: EM :: Wagering on ASOS Temperatures

 

[wxeyeNH]

87/769F  awaiting the cool air...

I wanted to give an update about the 81.8F dew that I reported 2 days ago.  I have one weather station, my Davis Vantage Pro2.  It is on a 2m tripod out in the field.  For years, I have used 2 standard consoles in different places of the house.  Several months ago I decided to upgrade and bought their new LED monitor.  I put one of the standard consoles away to use as a backup in the future.  

The new console works fine.  The temperatures on the new and old console is the same.  The new console is located in our sun room where I spend most of my time.  It recorded that 81.8F dew.  Later in the day I noticed my old console was reporting a dew about 2F lower.  Brian explained they ping the station at different times so perhaps that was why.  Yesterday I dug out my extra old console and plugged it in.  Just like my other old one the dews were about the same and remained that way for the rest of the day while the new console was always about 2F higher.  I called Davis and they were stumped.  I did figure out to go into the advance settings and lower the outside humidity display to match the other two.  So now everything is in sync, but it is weird. 

 

 

[dendrite]

4 minutes ago, TheClimateChanger said:

IEM says ASOS temperatures are based on 2-minute averages, perhaps that's the discrepancy. If it's two minute averaging, those temperatures jumps are plausible.

Source: EM :: Wagering on ASOS Temperatures

 

I swear I remember it being 5 min unless it was changed.

[dryslot]

The heat has really affected the thought processes on here................

[snowman21]

1 minute ago, dendrite said:

I swear I remember it being 5 min unless it was changed.

I think it still is a 5-minute average sampled every 10 seconds. That 2-minute/5-second thing looks more like wind measurements.

[dendrite]

3 minutes ago, snowman21 said:

I think it still is a 5-minute average sampled every 10 seconds. That 2-minute/5-second thing looks more like wind measurements.

I know it was 5 mins in 2011 because BOS had a raw minute of 104F in there surrounded by 103F and the high for the day went in as 103F.

[kdxken]

51 minutes ago, powderfreak said:

Back down to 81F.

That's a swing.

What happened from 1:40pm to 1:43pm?  And then 1:54pm to 1:55pm.

Ditty with a blowtorch ?

[dendrite]

Looks like Iowa St gets the 1-min data in within 2 days so we'll see.

[TheClimateChanger]

9 minutes ago, dendrite said:

I swear I remember it being 5 min unless it was changed.

That's how I remember it and found an old document from the EPA that has the same value.  With that said, Daryl Herzmann and IEM is an extremely reputable source, which would suggest it may have been changed at some time for consistency with wind measurements. Not sure. The WMO standard is for 5-minute averaging, but not all jurisdictions use that. The UKMET Office uses only 1-minute averaging for its platinum resistance thermometers, which I only recently learned from some complaining denialists from across the pond. These guys are always the biggest snowflakes. Oh, there's too much red on the weather map. The temperature is illegitimate because it's based on only a 1-minute average instead of a WMO 5-minute average! Etc., etc...

[dendrite]

@CoastalWx 7/22/2011 for BOS. 104F at 1949z

https://mesonet.agron.iastate.edu/cgi-bin/request/asos1min.py?station=BOS&tz=UTC&year1=2011&month1=7&day1=22&hour1=0&minute1=0&year2=2011&month2=7&day2=22&hour2=23&minute2=0&vars=tmpf&sample=1min&what=view&delim=comma&gis=no

[Typhoon Tip]

Plus, the sensor's offline at the moment so ... not likely unrelated