Spring 2025 Banter

[Wannabehippie]

Spring has sprung. Weather pattern seems to be in full spring mode now. Interior sections of the tri-state area might see some really warm conditions on Saturday. Everyone ready for spring weather?

[MJO812]

1 hour ago, Wannabehippie said:

Spring has sprung. Weather pattern seems to be in full spring mode now. Interior sections of the tri-state area might see some really warm conditions on Saturday. Everyone ready for spring weather?

No

[SnoSki14]

On 3/25/2025 at 8:03 PM, MJO812 said:

No

Blocking showing up on ensembles for 2nd week of April onward on EPS

[MJO812]

1 hour ago, SnoSki14 said:

Blocking showing up on ensembles for 2nd week of April onward on EPS

AI

[SnoSki14]

3 hours ago, MJO812 said:

AI

This doesn't mean it'll snow (it won't) just that there will probably be some chillier days

[MJO812]

On 3/28/2025 at 10:59 AM, SnoSki14 said:

This doesn't mean it'll snow (it won't) just that there will probably be some chillier days

AI still showing it and you are wrong. This is snow.

[MJO812]

4 hours ago, MJO812 said:

AI still showing it and you are wrong. This is snow.

And still showing  that 

[jm1220]

On 3/28/2025 at 7:45 AM, MJO812 said:

AI

Skynet's drunk. Hide the vodka.

In all seriousness though most models are cold, enough for another couple/few freezes for most away from the city.

[Brian5671]

14 hours ago, jm1220 said:

Skynet's drunk. Hide the vodka.

In all seriousness though most models are cold, enough for another couple/few freezes for most away from the city.

Not of that ever verifies or even comes close...agree with you, a couple more frosts and freeezes outside the urban areas

[MJO812]

15 hours ago, jm1220 said:

Skynet's drunk. Hide the vodka.

In all seriousness though most models are cold, enough for another couple/few freezes for most away from the city.

I doubt this verifies but we have seen snow in April.  I have no clue why people are shocked.

[Sundog]

3 minutes ago, MJO812 said:

I doubt this verifies but we have seen snow in April.  I have no clue why people are shocked.

Yea it's not like it's unprecedented. That doesn't mean I believe that it will snow of course. 

[forkyfork]

On 3/28/2025 at 7:45 AM, MJO812 said:

AI

your phone needs parental blocks on it that i control

[donsutherland1]

Artificial Intelligence (AI) has garnered significant attention this winter and early spring in forecasting. Multiple AI initiatives are ongoing. In some cases, such as forecast 500 mb patterns, AI has shown improvement over the best-of-class operational ECMWF model.

One area that has not garnered as much attention is longer-range forecasting. Can AI make advances that push the frontiers of long-range forecasting? Chaos and non-linearity become more important as one expands the forecasting timeframe.

To take a closer look, I constructed some AI models to forecast the coming April. The AI-generated standard error and coefficient of determination hint at a large improvement over linear forecasting techniques. I say "hint," because I remain cautious about a hindcasting problem where things look good against past data only to break down in an actual forecasting situation. Consider, for example, the initial promise and more limited impact of using the Siberian Snow Advance Index (SAI) for winter forecasting.

I will share the results here for New York City (Central Park).

April 2025 AI Forecast:
Monthly mean temperature: 53.7°
Monthly maximum temperature: 84°
Monthly minimum temperature: 35°
Monthly precipitation: 4.32"

Those are equivalent to ensemble means. Some additional information:

Monthly mean temperature:
Below 52°: 17% trees or members
Below 53°: 41% of members
54° or above: 51% of members
55° or above: 28% of members
56° or above: 4% of members

This indicates that although somewhat more members show an above normal temperature, the smaller number of cool members are sufficiently cool to skew the overall average.

Monthly precipitation:
Below 3": 25%
4" or above: 61%
5" or above: 21%

Monthly Snowfall:
No measurable snowfall: 86% of members
Trace of snow: 13% of members
Measurable snow: 1% of members

I also inquired about how many members showed an April freeze. 29% had a monthly minimum temperature of 32° or below.

1991-2020 Baselines:

Monthly Mean: 53.7°
Monthly Maximum: 83°
Monthly Minimum: 33°
Monthly Precipitation: 4.09"
Monthly Snowfall: 0.4"

Comparison: CFSv2 Forecasts:

Miscellaneous:

The AI model suggested that both Phoenix (above normal on the CFSv2) and Boston (normal on the CFSv2) would be above normal with April mean temperatures of 74.1° and 49.4° respectively. The AI model also suggested that Phoenix would have an April monthly maximum of 100° (range of scenarios: 97°-105° with 47% of members at 100° or above). In terms of rainfall, the mean forecast for Phoenix was 0.22" (normal). 33% of members showed no measurable rainfall; 67% had measurable rainfall; 28% had 0.25" or more; 13% had 0.50" or more; and, 8% had 1.00" or more.

My expectation:

I am agnostic about the AI forecasts. Aside from my own thinking that an April freeze is unlikely and that NYC has very likely seen its last measurable snowfall, I have no strong views about the possible outcomes. I note that this time around, the AI forecasts seem to be broadly in line with the CFSv2 ideas. 

Outcome:

The outcome will be verified at the end of the month.