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October 2019 General Discussions & Observations Thread


Rtd208
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On 10/18/2019 at 11:58 AM, frd said:

You might like this research , it touches on your statement. There is discussion on absolute versus relative anomalies .

This is a new paper on how that warm pool in the central and western equatorial Pacific threw off the winter forecasts last year.  We were discussing this last winter. So it’s good to see a study done on it. But only the abstract is available.

 

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19 hours ago, donsutherland1 said:

Milder conditions will gradually return in coming days. Post-Tropical Storm Nestor will likely track rapidly to the east northeast off the Middle Atlantic coast and out to sea. Its rain should pass south of the New York City Metro area later tomorrow and tomorrow night. There is a small chance that a few showers could reach the area. Parts of the Middle Atlantic region including Washington and Baltimore could see a period of rain from Nestor.

The last week of October will likely start mild but end with a cool shot. The cool conditions increasingly appear likely to persist through the first week of November as the Arctic Oscillation goes negative for at least a time.

The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was +0.4°C for the week centered around October 9. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.88°C and the ENSO Region 3.4 anomaly has averaged +0.12°C. A neutral ENSO is currently the base case for Winter 2019-20.

Since 1981, approximately one out of every seven December cases involved a neutral ENSO. In general, a neutral ENSO in which Region 1+2 had a cold anomaly and Region 3.4 had a warm anomaly (as has been the case in the 6 week moving average) saw a warmer than normal December. Such neutral ENSO cases accounted for about 27% of all neutral ENSO December cases during the 1981-2018 period. This data does not consider blocking, as it is too soon to be confident about that factor in December. However, the greatest warmth coincide with a negative PDO while the coldest outcome coincided with a strongly positive PDO (+1.00 or above for December). Therefore, the first part of winter could start off milder than normal in the Middle Atlantic and southern New England regions.

The SOI was +10.63 today.

Today, the preliminary Arctic Oscillation (AO) figure was -0.989.

Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September through November in New York City was 58.9° (59.6° adjusted). All cases featured a warmer than normal fall. There remains a potential for autumn 2019 to rank among the 30 warmest cases on record. For New York City, that would translate into a September-November mean temperature of at least 58.8°.

In August, the AO averaged -0.722 and in September the AO rose to +0.306. The possible transition to predominantly positive values from September into October has been a relatively uncommon occurrence. Since 1950, only 1963 and 2011 saw a transition of an August value of -0.500 or below to positive values in September and a positive average in October. Both cases featured a warmer than normal November in the Middle Atlantic and southern New England areas. Despite what might be a somewhat cooler than normal start to November, a warmer than normal outcome for the month as a whole remains likely.

On October 18, the MJO was in Phase 2 at an amplitude of 1.362 (RMM). The October 17-adjusted amplitude was 1.117.

In the two prior cases when the MJO moved into Phase 1 in late September or early October and then remained in Phase 1 for 12 or more consecutive days as occurred this year, the average decline in the 14-day average temperature for the 2-3 weeks that followed the MJO's moving out of Phase 1 was gradual. The current long-duration Phase 1 episode suggests that the second half of October could be warmer than normal. For New York City, an October mean temperature of 58.5°-59.5° (1.6° to 2.6° above normal) would be implied by those earlier long-duration Phase 1 cases. Based on the sensitivity analysis, the estimated October mean temperature is currently near 59.0°.

Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal October is approximately 78%.

Its rain should pass south of the New York City Metro area later tomorrow and tomorrow night. There is a small chance that a few showers could reach the area. Parts of the Middle Atlantic region including Washington and Baltimore could see a period of rain from Nestor.

 It’s raining to Canada.... almost every model busted?

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21 minutes ago, qg_omega said:

Its rain should pass south of the New York City Metro area later tomorrow and tomorrow night. There is a small chance that a few showers could reach the area. Parts of the Middle Atlantic region including Washington and Baltimore could see a period of rain from Nestor.

 It’s raining to Canada.... almost every model busted?

Yes. Many models missed how far north the rain came, even as the steadiest and heaviest rain was confined to such cities as Baltimore, Richmond, and Washington.

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some weather people are saying last night nam was south so you can't give the nam any credit..
Why go by what other people said? The Nam is freely available for you to see and make your own opinion. Anyway the Nam scored a big victory with this today. Even the nws discounted it all week long saying the precipitation on the Nam is too far north. The euro and gfs aren't always the best.

Sent from my Samsung Note 8

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22 minutes ago, NycStormChaser said:

Why go by what other people said? The Nam is freely available for you to see and make your own opinion. Anyway the Nam scored a big victory with this today. Even the nws discounted it all week long saying the precipitation on the Nam is too far north. The euro and gfs aren't always the best.

Sent from my Samsung Note 8
 

Yeah several times during the past couple days, they mentioned in their discussion about it being an outlier and discounting it.

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Post-Tropical Storm Nestor took a track closer to the coast bringing steady rain to the New York City area. Rather than turning sharply out to sea from eastern North Carolina or southeast Virginia, Nestor came northward and moved across the southern portion of the Delmarva Peninsula.

Although this subtle northwestward shift in the storm track was most noticeable with today's precipitation, it could also hint that the western Atlantic ridge may be somewhat stronger and more expansive than had previously been modeled.

Rainfall amounts today through 8 pm included:

Baltimore: 1.34"
Islip: 0.41"
New York City: 0.51"
Newark: 0.58"
Norfolk: 1.85"
Philadelphia: 0.48"
Poughkeepsie: 0.21"
Richmond: 1.59"
Sterling, VA: 1.43" (old daily record: 1.27", 1976)
Washington, DC: 1.60"

During the next 7-10 days, temperatures will average warmer than normal. However, October could end with a cool shot. The cool conditions will likely to persist through the first week of November as the Arctic Oscillation goes negative for at least a time.

The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was +0.4°C for the week centered around October 9. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.88°C and the ENSO Region 3.4 anomaly has averaged +0.12°C. A neutral ENSO is currently the base case for Winter 2019-20.

Since 1981, approximately one out of every seven December cases involved a neutral ENSO. In general, a neutral ENSO in which Region 1+2 had a cold anomaly and Region 3.4 had a warm anomaly (as has been the case in the 6 week moving average) saw a warmer than normal December. Such neutral ENSO cases accounted for about 27% of all neutral ENSO December cases during the 1981-2018 period. This data does not consider blocking, as it is too soon to be confident about that factor in December. However, the greatest warmth coincide with a negative PDO while the coldest outcome coincided with a strongly positive PDO (+1.00 or above for December). Therefore, the first part of winter could start off milder than normal in the Middle Atlantic and southern New England regions.

The SOI was +11.21 today.

Today, the preliminary Arctic Oscillation (AO) figure was -0.870.

Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September through November in New York City was 58.9° (59.6° adjusted). All cases featured a warmer than normal fall. There remains a potential for autumn 2019 to rank among the 30 warmest cases on record. For New York City, that would translate into a September-November mean temperature of at least 58.8°.

In August, the AO averaged -0.722 and in September the AO rose to +0.306. The possible transition to predominantly positive values from September into October has been a relatively uncommon occurrence. Since 1950, only 1963 and 2011 saw a transition of an August value of -0.500 or below to positive values in September and a positive average in October. Both cases featured a warmer than normal November in the Middle Atlantic and southern New England areas. Despite what might be a somewhat cooler than normal start to November, a warmer than normal outcome for the month as a whole remains likely.

On October 19, the MJO was in Phase 2 at an amplitude of 1.664 (RMM). The October 18-adjusted amplitude was 1.361.

In the two prior cases when the MJO moved into Phase 1 in late September or early October and then remained in Phase 1 for 12 or more consecutive days as occurred this year, the average decline in the 14-day average temperature for the 2-3 weeks that followed the MJO's moving out of Phase 1 was gradual. The current long-duration Phase 1 episode suggests that the second half of October could be warmer than normal. For New York City, an October mean temperature of 58.5°-59.5° (1.6° to 2.6° above normal) would be implied by those earlier long-duration Phase 1 cases. Based on the sensitivity analysis, the estimated October mean temperature is currently near 58.5°.

Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal October is approximately 75%.

With today's rainfall, there is an implied 61% probability (1971-2018 data) that New York City will reach at least 50.00" annual precipitation this year.

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2 hours ago, doncat said:

Yeah several times during the past couple days, they mentioned in their discussion about it being an outlier and discounting it.

sometimes the outlier is the correct solution.  While the big amts the NAM had a few runs didn't pan out, it had the best general idea of precip well into New England.

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“Yet another 100° heat index today... this is really getting old!! We've never used the pool this late in the year, but records are meant to be broken I guess. A rhubarb gin & tonic helps take the edge off. ;-) #Miami “

 

See, I disregard this post as sensationalist garbage when you tell us you have never used a pool in late October in Miami.

Miami is swimmable year round with the exception of some cool shots that happen in the dead of winter. Always has been.

That’s why I fly full flights to S florida all winter long ✈️

 

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5 hours ago, bluewave said:

I guess we shouldn’t be surprised that the storm came further north with the SE Ridge on steroids.

 

I really can not understand the glibness and stupidity of tweets like this. This is alarming, no cause for celebration/unwinding. your city's going to be underwater in the not so distant future dude

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1 hour ago, jfklganyc said:

“Yet another 100° heat index today... this is really getting old!! We've never used the pool this late in the year, but records are meant to be broken I guess. A rhubarb gin & tonic helps take the edge off. ;-) #Miami “

 

See, I disregard this post as sensationalist garbage when you tell us you have never used a pool in late October in Miami.

Miami is swimmable year round with the exception of some cool shots that happen in the dead of winter. Always has been.

That’s why I fly full flights to S florida all winter long ✈️

 

Maybe they dont have a heated pool and need the pool water to be 85 to go in? Alot of people down there dont have heaters and don't swim unless the water is like a tub (most of my family lives in S. Fla)

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