My Summer Outlook 2019 VERIFICATION

[Isotherm]

Summer outlook can be found here:

 

http://www.lightinthestorm.com/

 ***Scroll down for temperature/pcpn departure forecast details and maps, as well as 90F day forecast.

 

NJ map of total snowfall for the 2018-19 winter:

 

http://www.lightinthestorm.com/nj-snowfall

 

Comments and/or inquiries are appreciated.

[Roger Smith]

I came to very similar conclusions from a different research perspective (summary posted in whatever we call the main forum, I call it the Quiet Zone). 

Would not be surprised if there is some exceptional heat at some point in July or August as you seem to be implying. 

Good luck with your forecast, if you're right, I'm right. 

[LibertyBell]

I see quite a few going for a warm and dry summer but enhanced risk of tropical activity later on along the east coast

[Isotherm]

5 hours ago, Roger Smith said:

I came to very similar conclusions from a different research perspective (summary posted in whatever we call the main forum, I call it the Quiet Zone). 

Would not be surprised if there is some exceptional heat at some point in July or August as you seem to be implying. 

Good luck with your forecast, if you're right, I'm right. 

 

 

Thanks, Roger, and I concur, [while the language was qualified somewhat due to long range precautions] I saw some distinct signals for potential major heat. Good luck with your forecast as well. 

[CIK62]

Isn't it taken for granted that any 3-month (seasonal forecast) will come in AN a disproportionate number of times, like weighted dice?      The average age of all Top Ten Coolest Summers [NYC] is about 120 years.     For all the Top Ten Warmest, the age is about 35 years!    I am guessing this extends all the way down/up  the line in both cases.

It appears sagacious to say nothing, unless you really have evidence for BN.

Did you consider the Stratospheric Warming which is affecting southern latitudes too, as of late?    Weaker  SE Ridge a possible outcome here.

I am hoping for short-term heatwaves of three or fewer days duration.     Your 26, 90-degree days implies at least one 5/6+stretch, I would bet.

 

[Isotherm]

The SSTA profile similarities b/t present [2019] and late May 2002 are quite striking. The degree of structural symmetry is impressive, on a hemispheric and even global scale.

 

 

 

[Isotherm]

On 5/26/2019 at 5:40 PM, CIK62 said:

Isn't it taken for granted that any 3-month (seasonal forecast) will come in AN a disproportionate number of times, like weighted dice?      The average age of all Top Ten Coolest Summers [NYC] is about 120 years.     For all the Top Ten Warmest, the age is about 35 years!    I am guessing this extends all the way down/up  the line in both cases.

It appears sagacious to say nothing, unless you really have evidence for BN.

Did you consider the Stratospheric Warming which is affecting southern latitudes too, as of late?    Weaker  SE Ridge a possible outcome here.

I am hoping for short-term heatwaves of three or fewer days duration.     Your 26, 90-degree days implies at least one 5/6+stretch, I would bet.

 

 

The background state is certainly a not insignificant factor inculcated in the overall long range forecast equation, from my standpoint. 

[NYCweatherNOW]

So another way of putting it ,warm and dry? 

[denvillenj]

thanks Isotherm for the snowfall map.  I look forward to seeing it every year 

[Isotherm]

http://www.lightinthestorm.com/archives/1195

 

 

VERIFICATION

Temperature Departure Forecast JJA: +1 to +2

NYC/NJ Local Station Departures:

NYC: +1.2

LGA: +2

EWR: +1.3

JFK: +1.2

BDR: +1.9

 

ISP: +2.1

 

Mean of all stations: +1.6

 

This fell directly within the target range. The notion that June would be near normal with increasing heat and humidity in July and August was correct, as well as the forecast for at least one major heat spell.

 

Precipitation Forecast for JJA was wetter than normal. Results:

 

NYC: +0.49″

EWR: +2.1″

LGA: +0.53″

JFK: +0.75″

BDR: +0.92″

ISP: -0.35″

 

Mean of all stations = +0.74″ wetter than normal

 

This was a wet and active T-storm season overall, as anticipated in the Northeast and Mid-Atlantic.

 

90 degree day projections / actual:

 

90 Degree Day Projections / actual  through 9/2/2019:

BOS: 14 / 14 error: 0
NYC: 26 / 14 error: +12
LGA: 30 / 23 error: +7
EWR: 33 / 24 error: +9
PHL: 36 / 31 error: +5
DCA: 45 / 52 error: -7
RDU: 52  / 61 error: -9

 

 

Total error: +17 [overall, slightly warmer than anticipated]

 

This was a very good forecast considering the high level of difficulty; the numbers were virtually on target for the Mid-Atlantic and New England. It was slightly too many for the PHL-NYC corridor.

 

Summer Outlook 2019 Grade:

 

This will be considered a hit. The forecast was “A” locally. Including the nation-wide picture, the expectation for a very hot West Coast and Mid-atlantic/SE US was correct, and warmer than normal most other locations. The primary flaw was slightly cooler anomalies in the N/C Plains. The nationwide grade is therefore a B+.

 

The overall final grade is A-

 

 

 

 

 

 

 

[nzucker]

We didn't really have "increasing heat and humidity" in August. I think the month finished +0.3F with 3 days that hit exactly 90F. That's not exactly a warm August.

 

[Isotherm]

2 hours ago, nzucker said:

We didn't really have "increasing heat and humidity" in August. I think the month finished +0.3F with 3 days that hit exactly 90F. That's not exactly a warm August.

 

 

Dew points were quite high most of August through the third week. It was very humid, and most in the Northeast corridor were slightly warmer than normal. While August was slightly cooler departure wise than expected, July compensated. The trimonthly range is most important for long range seasonals (which directly hit). I often debate whether I should even include monthlies, because it's substantially higher difficulty than the already difficult seasonal, and people will tend to myopically focus on any comparatively diminutive error in one of the monthlies. 

And the "increasing heat and humidity" was taken a bit out of context. July and August certainly featured increased heat and humidity compared to June, with respect to normal. The assertion in the outlook was that the first 1/3 of summer would be coolest relative to normal with increasing warmth/humidity thereafter, which verified objectively.

[Isotherm]

This is a warmer than average August for most of the Northeast and Mid-Atlantic. Slightly warmer than normal (but remember, the forecast for August was not very hot either).

 

[nzucker]

3 hours ago, Isotherm said:

 

Dew points were quite high most of August through the third week. It was very humid, and most in the Northeast corridor were slightly warmer than normal. While August was slightly cooler departure wise than expected, July compensated. The trimonthly range is most important for long range seasonals (which directly hit). I often debate whether I should even include monthlies, because it's substantially higher difficulty than the already difficult seasonal, and people will tend to myopically focus on any comparatively diminutive error in one of the monthlies. 

And the "increasing heat and humidity" was taken a bit out of context. July and August certainly featured increased heat and humidity compared to June, with respect to normal. The assertion in the outlook was that the first 1/3 of summer would be coolest relative to normal with increasing warmth/humidity thereafter, which verified objectively.

I mean overall your forecast was a hit, but the idea of heat returning in the 2nd half of August never really came to pass. 

July was an extremely hot month, nearly up there with '55 and '66. 

Also, you went a little heavy on 90-degree days; part may be attributable to the vegetation in Central Park.

 

 

[Isotherm]

5 hours ago, nzucker said:

I mean overall your forecast was a hit, but the idea of heat returning in the 2nd half of August never really came to pass. 

July was an extremely hot month, nearly up there with '55 and '66. 

Also, you went a little heavy on 90-degree days; part may be attributable to the vegetation in Central Park.

 

 

 

Yes, no disagreement there. The second half of August tended cooler and 90F days were too high in the PHL-NYC corridor as noted in the verification above. There may actually be 1 to 3 more chances for 90F for many of these stations but we'll see on that.

[psv88]

14 hours ago, Isotherm said:

 

Yes, no disagreement there. The second half of August tended cooler and 90F days were too high in the PHL-NYC corridor as noted in the verification above. There may actually be 1 to 3 more chances for 90F for many of these stations but we'll see on that.

Good forecast Tom. Looking forward to your winter outlook. 

[Isotherm]

13 minutes ago, psv88 said:

Good forecast Tom. Looking forward to your winter outlook. 

 

Thanks, Paul. 

I'm envisioning another interesting outlook season -- think there will be a bit more divergence in forecasts this year.

[nzucker]

10 hours ago, Isotherm said:

 

Thanks, Paul. 

I'm envisioning another interesting outlook season -- think there will be a bit more divergence in forecasts this year.

I like the looks of a weak Niña, warm NP, and low solar activity.

How is ozone and strat temps?

[LibertyBell]

On 9/8/2019 at 8:42 AM, Isotherm said:

 

Yes, no disagreement there. The second half of August tended cooler and 90F days were too high in the PHL-NYC corridor as noted in the verification above. There may actually be 1 to 3 more chances for 90F for many of these stations but we'll see on that.

we probably wont have another historically hot summer until 2021 (you know why), what I mean is dry heat with rainfall under 3" for each summer month, like 2010.

[WEATHER53]

Yes. Very good again.

When is your winter?

[Isotherm]

On 10/15/2019 at 12:47 AM, WEATHER53 said:

Yes. Very good again.

When is your winter?

 

Thanks, @WEATHER53. Should be in approximately 2-3 weeks.

[WEATHER53]

4 hours ago, Isotherm said:

 

Thanks, @WEATHER53. Should be in approximately 2-3 weeks.

I did mine over in mid Atlantic so along with where else  you put yours could you put yours in that thread?

[JBG]

On 9/8/2019 at 8:42 AM, Isotherm said:

 

Yes, no disagreement there. The second half of August tended cooler and 90F days were too high in the PHL-NYC corridor as noted in the verification above. There may actually be 1 to 3 more chances for 90F for many of these stations but we'll see on that.

Well, October 2, 2019.