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February 2019 Forecast Discussion and Observations


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first one to complain about “nickel and dime” events get banished 

Below is a signal i've truly yet to see all winter long; a stable constructive interference, intra-seasonal signal with what also looks like a dual-low frequency mode along and east of 180 degrees. Th

Reiterating a point I mentioned in a tweet the other day, I'm not overly enthused by this pattern due in part to the largely -PNA & overall, a mid latitude zonal height field. That being said, you

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41 minutes ago, Nchaboy said:

-epo/-pna are going to be tough for us on the coast. The SE ridge might be a killer if we increase the heights on the EC. 

 

The SE ridge will likely become muted and will not be a robust feature as we get past day 10.

 

You want a little SE ridge , as - EPOs favor the coast , they push the Arctic boundary to the coast.

Its the natural teleconnection.

 

Coupled with the MJO going into p 8 and p1 that favors depressing the ridge.

 

Keep the waves weak and you're in business.

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9 minutes ago, Snowman11 said:

A strong negative epo will suppress the heights on the coast. Have to watch out for that.

 

I'm not remotely concerned about that.

I'd be more concerned about the EPO being oriented too far west and producing Apps runners or coastal huggers than suppression.

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Readings around the New York City area surged into the 60s today under bright sunshine. Additional springlike warmth is on tap for tomorrow.

 

The SOI was -0.91 today.

 

The Arctic Oscillation (AO) continues to rise quickly from its February 1 minimum of -3.537. Today's preliminary value was -1.510. The preliminary average for meteorological winter is -0.422.

 

On February 3, the MJO was in Phase 7 at an amplitude of 1.386 (RMM). That amplitude had risen slightly from the February 2-adjusted figure of 1.274.

 

There remains some uncertainty about the MJO's progression. There remains a distinct possibility that the MJO could fall to low amplitude or return to Phase 6 in coming days. Afterward, it should return to Phase 7 before making a possible slow advance toward Phase 8, which it could approach or reach within a few days of mid-month. Outlying guidance--the EPS idea of a fairly fast move into Phase 8 and the Canadian Ensemble forecast of a shift to Phase 5 and slow move toward Phases 6 and 7 afterward-- is discounted. Outlying guidance has typically fared poorly in recent weeks.

 

Phase 6 at a high amplitude and Phase 7 at low amplitude typically favor a positive AO. As a result, the AO will likely continue to rise in the coming days. There remains strong ensemble consensus for this rise and growing consensus for the AO's reaching positive values in about 2-6 days.

 

Based on sensitivity analysis applied to the latest guidance, the probability that the first week of February will see above normal readings in and around New York City has now risen to near 95%. However, colder air should return during coming weekend.

 

There remains a possibility that a predominantly colder than normal regime could then lock in for at least a 2-3 week period, especially as the EPO is expected to go negative and blocking could redevelop.

 

Based on the latest ENSO Region data, the currently fading El Niño is not likely to evolve into a central Pacific-based event this month. Instead, it will retain the characteristics of a basin-wide event. Overall, neutral-warm to possibly borderline El Niño conditions will be present for much or all of February.

The latest data is as follows:

 

Region 1+2 anomaly: +1.0°C (4-week moving average: +0.65°C)

Region 3.4 anomaly: +0.30°C (+0.40°C)

 

This development suggests that the probability of a snowy February has decreased. Should the modeled AO+/PNA- pattern develop, that would reinforce the idea of a lower than climatological probability of snowfall in the Middle Atlantic region.

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12 minutes ago, donsutherland1 said:

Readings around the New York City area surged into the 60s today under bright sunshine. Additional springlike warmth is on tap for tomorrow.

 

The SOI was -0.91 today.

 

The Arctic Oscillation (AO) continues to rise quickly from its February 1 minimum of -3.537. Today's preliminary value was -1.510. The preliminary average for meteorological winter is -0.422.

 

On February 3, the MJO was in Phase 7 at an amplitude of 1.386 (RMM). That amplitude had risen slightly from the February 2-adjusted figure of 1.274.

 

There remains some uncertainty about the MJO's progression. There remains a distinct possibility that the MJO could fall to low amplitude or return to Phase 6 in coming days. Afterward, it should return to Phase 7 before making a possible slow advance toward Phase 8, which it could approach or reach within a few days of mid-month. Outlying guidance--the EPS idea of a fairly fast move into Phase 8 and the Canadian Ensemble forecast of a shift to Phase 5 and slow move toward Phases 6 and 7 afterward-- is discounted. Outlying guidance has typically fared poorly in recent weeks.

 

Phase 6 at a high amplitude and Phase 7 at low amplitude typically favor a positive AO. As a result, the AO will likely continue to rise in the coming days. There remains strong ensemble consensus for this rise and growing consensus for the AO's reaching positive values in about 2-6 days.

 

Based on sensitivity analysis applied to the latest guidance, the probability that the first week of February will see above normal readings in and around New York City has now risen to near 95%. However, colder air should return during coming weekend.

 

There remains a possibility that a predominantly colder than normal regime could then lock in for at least a 2-3 week period, especially as the EPO is expected to go negative and blocking could redevelop.

 

Based on the latest ENSO Region data, the currently fading El Niño is not likely to evolve into a central Pacific-based event this month. Instead, it will retain the characteristics of a basin-wide event. Overall, neutral-warm to possibly borderline El Niño conditions will be present for much or all of February.

The latest data is as follows:

 

Region 1+2 anomaly: +1.0°C (4-week moving average: +0.65°C)

Region 3.4 anomaly: +0.30°C (+0.40°C)

 

This development suggests that the probability of a snowy February has decreased. Should the modeled AO+/PNA- pattern develop, that would reinforce the idea of a lower than climatological probability of snowfall in the Middle Atlantic region.

This is the other issue, that @donsutherland1 has perfectly explained. The warm waters continue to be where we don’t want them. It has been one of the biggest reasons this winter has failed imo 

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Just now, Allsnow said:

This is the other issue, that @donsutherland1 has perfectly explained. The warm waters continue to be where we don’t want them. It has been one of the biggest reasons this winter has failed imo 

Doesn't man we can't cash in on a 1-2 week gradient pattern during the peak snowfall climo. ;) 

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1 minute ago, Snowman11 said:

Weeklies failed like the other models have. This time we will have the mjo in our favor and a negative epo.

The weeklies also now have a +ao for February. It agrees with the rest of the guidance now. Re: -pna -epo +ao southeast ridge 

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+ AO means nothing when the flow gets pushed over the pole and thru the UMW as a result of a -EPO

 

+AO in this regime is not the kiss of death as long as you hold onto the pos pushing poleward thru Alaska

 

20190204_141618.png

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