September Medium/ Long Range

[Weather Will]

Latest WB EURO weeklies for September.  Looks like more perfect fall weather, although we need rain.

[Weather Will]

Pretty sparse late week rain  chances on the WB 12Z globals.

[Jebman]

Look I apologize for posting this stuff in the modeling long range thread. But I need a real meteorologist like Millville Wx, high risk, WxUSAF,  wxmeddler, or any other red tagged Met to explain this nomenclature to me.

My fields are software engineering and AI engineering, not these apparently statistical terms. I am not really a weather person, only a silly snow weenie in winter wishing 4 feet of snow on DCA from one storm.

This paragraph is from today's AFD for AUS.

The rainy and cloudy weather will support cooler temperatures
beginning this weekend. With a thermal trough in our area during
this period, showers and storms could be more effective at producing
rain-cooled air. The approaching front may also contribute some
cooler air depending how far south it gets, though given the time of
year, most of the cooler temperatures will probably be rain and
cloud driven. This introduces significant uncertainty in
temperatures as illustrated by 7 to 10 degree interquartile ranges
in NBM QMD maximum temperatures on Sunday and Monday. Given the
large uncertainties, the current temperature forecast is aligned
with the NBM, featuring highs in the 80s to low 90s Sunday and
Monday before gradually warming back up into midweek after the
active weather pattern passes.

 

What I would like a meteorologist to do for me here is to please explain to me in 4th grade terms, what interquartile means. This stuff is WAY above my paygrade as well as centuries above my IQ level too. lmao

 

Thanks in advance, I am sorry for posting this in the long range thread BUT I need a real Met to try and explain this term to me.

Another thing, what are standard deviations? What do meteorologists mean when they say in an area forecast disco, that moisture is several standard deviations above normal for that time of year?

 

Might have to send someone some XRP for defining INTERQUARTILE. And standard deviation.

This time next year, xrp is going to be at least 75 dollars a coin. Right now it is about 2.30 I think. It's gonna go up. By 2030 it is gonnabe about 650 a coin.

 

[Weather Will]

If you did not get rain today, no wet weather in sight over the next week. WB 18Z EPS:

[CAPE]

Mostly dry but also normal to below normal temps through mid month. Longwave pattern supports surface HP to our NW/N/NE throughout.

[frd]

Late month warm up seems to be a possiblity.

Not unusual in Septembers that feature cool shots such as this month based on medium range modeling. 

 

[mitchnick]

15 hours ago, frd said:

Late month warm up seems to be a possiblity.

Not unusual in Septembers that feature cool shots such as this month based on medium range modeling. 

 

The regular Eps has been too warm at range since the start of August while the AI version has been better. Maybe the trend continues and maybe not. Either way, until and unless the regular Eps can prevail, I wouldn't be too concerned with that map. Otoh, even if right, we're real close to the +.50-+1.0C line, so a couple degrees F isn't a scorcher.

[Rhino16]

On 9/4/2025 at 1:40 PM, Jebman said:

Look I apologize for posting this stuff in the modeling long range thread. But I need a real meteorologist like Millville Wx, high risk, WxUSAF,  wxmeddler, or any other red tagged Met to explain this nomenclature to me.

This introduces significant uncertainty in temperatures as illustrated by 7 to 10 degree interquartile ranges in NBM QMD maximum temperatures on Sunday and Monday. What I would like a meteorologist to do for me here is to please explain to me in 4th grade terms, what interquartile means. This stuff is WAY above my paygrade as well as centuries above my IQ level too. lmao

 

Basically, we can take a set of numbers and break them into quarters. Just like we do with the months in a year. 

Interquartile is the set of numbers between Q1 and Q3, the numbers in the middle of the dataset. So if the models are putting out numbers that are very spread out and uncertain like in your example, the Interquartile Range will be high. If the models are all putting out similar numbers, the difference between Q3 and Q1 will be low, so making a temperature forecast might be easier.

[Weather Will]

6Z EURO AI:  maybe around the 16th or 22nd we see some rain.

[Jebman]

On 9/8/2025 at 9:08 AM, Rhino16 said:

Basically, we can take a set of numbers and break them into quarters. Just like we do with the months in a year. 

Interquartile is the set of numbers between Q1 and Q3, the numbers in the middle of the dataset. So if the models are putting out numbers that are very spread out and uncertain like in your example, the Interquartile Range will be high. If the models are all putting out similar numbers, the difference between Q3 and Q1 will be low, so making a temperature forecast might be easier.

Hey Rhino16, thank you very much!

Why haven't they red-tagged you yet?

[87storms]

 

On 9/4/2025 at 1:40 PM, Jebman said:

Look I apologize for posting this stuff in the modeling long range thread. But I need a real meteorologist like Millville Wx, high risk, WxUSAF,  wxmeddler, or any other red tagged Met to explain this nomenclature to me.
My fields are software engineering and AI engineering, not these apparently statistical terms. I am not really a weather person, only a silly snow weenie in winter wishing 4 feet of snow on DCA from one storm.
This paragraph is from today's AFD for AUS.

The rainy and cloudy weather will support cooler temperaturesbeginning this weekend. With a thermal trough in our area duringthis period, showers and storms could be more effective at producingrain-cooled air. The approaching front may also contribute somecooler air depending how far south it gets, though given the time ofyear, most of the cooler temperatures will probably be rain andcloud driven. This introduces significant uncertainty intemperatures as illustrated by 7 to 10 degree interquartile rangesin NBM QMD maximum temperatures on Sunday and Monday. Given thelarge uncertainties, the current temperature forecast is alignedwith the NBM, featuring highs in the 80s to low 90s Sunday andMonday before gradually warming back up into midweek after theactive weather pattern passes.

 

 
What I would like a meteorologist to do for me here is to please explain to me in 4th grade terms, what interquartile means. This stuff is WAY above my paygrade as well as centuries above my IQ level too. lmao
 
Thanks in advance, I am sorry for posting this in the long range thread BUT I need a real Met to try and explain this term to me.
Another thing, what are standard deviations? What do meteorologists mean when they say in an area forecast disco, that moisture is several standard deviations above normal for that time of year?
 
Might have to send someone some XRP for defining INTERQUARTILE. And standard deviation.
This time next year, xrp is going to be at least 75 dollars a coin. Right now it is about 2.30 I think. It's gonna go up. By 2030 it is gonnabe about 650 a coin.
 

Standard deviation is just the average distance of each value in a dataset from the dataset’s mean. In a normal (or near normal) distribution (tied to the central limit theorem), then 1, 2, and 3 standard deviations from the mean cover ~68/95/99.7% of the data. So by nature >= 2-3 standard deviations away from the mean implies <= 5% chance of occurrence.

And IQR is just the middle 50% of the ordered data. Replacing a dataset’s tails with anomalies will skew the mean and increase the standard deviation, but not affect the IQR (or even median).

There’s nuances to all of this, but that’s the gist of it.

[Rhino16]

11 hours ago, Jebman said:

Hey Rhino16, thank you very much!

Why haven't they red-tagged you yet?

Not sure, I put in a request back in May, just waiting to hear back and provide whatever proof they need.

[nw baltimore wx]

8 minutes ago, Rhino16 said:

Not sure, I put in a request back in May, just waiting to hear back and provide whatever proof they need.

My guess is that @stormtracker is less active here in the summer months. Maybe one of the local MA administrators will reach out.

[WxUSAF]

20 minutes ago, Rhino16 said:

Not sure, I put in a request back in May, just waiting to hear back and provide whatever proof they need.

 

10 minutes ago, nw baltimore wx said:

My guess is that @stormtracker is less active here in the summer months. Maybe one of the local MA administrators will reach out.

Posted a request in the mod forum but that place is a ghost town. @dendrite can you help?