donsutherland1

DCA _ NYC _ BOS _ ORD _ ATL _ IAH _ DEN _ PHX _ SEA +3.5 +2.7 +2.2 +5.3 +2.0 +0.9 +2.7 +0.2 +3.0

Here's the composite outcome for an AO-/EPO- pattern for the November 15-December 15 period: Nevertheless, there is an unpleasant warmer cluster: If North America is flooded with Pacific Air courtesy of the ongoing strong El Niño and/or the EPO-/AO- fails to develop, warmer outcomes would be on the table. One clue might be how much warmth is in Canada 5-10 days before the forecast period. If Canada is largely covered by warm anomalies, particularly within five days of the development of the EPO-/AO- pattern, that has often been a precursor to the warmer cluster.

Both the ECMWF and AIFS show 1" or more precipitation across the region. Here are the average figures for Central Park (IFS-AIFS mean). The conventional ECMWF (IFS) is currently wetter than the AIFS.

The latest NBM continues to show a mild start to November for the New York City area.

A photo:

Currently, the extended range shows the development of an EPO+/WPO+/AO-/NAO-/PNA+ pattern. The ECMWF-AIFS is shows temperature anomalies consistent with such a pattern at 240 hours. Its solution is especially close to a cluster of past teleconnection cases. When rolled forward 5 days, the cluster matches up quite well with the 360-hour ECMWF-AIFS forecast. I narrowed the temperature range so the anaomalies are easier to see. So far, there's nothing truly eventful. However, five days out, one see a lot more cool air in the CONUS. Canada remains mild. That would be at odds with the powerful El Niño in the run-up to December. However, it could be a hint of how the potential early-season stratospheric warming event impacts North America. What that suggests is that November 20 +/- a few days might be a reasonable timeframe to begin to see effects from the stratospheric warming event, should it occur. For now, that's speculative. The El Niño will likely remain the dominant factor shaping North American patterns, so even a cooldown might not necessarily mean unseasonable cold. The ECMWF weekly forecast for November 23-30 shows this quite well. The true area of cool anomalies is smaller, while a large part of the southern half of the CONUS has near normal readings. Finally, for those who track teleconnections, NOAA is no longer updating daily EPO and WPO values.

It seems odd that smoke would have created the phenomenon, but it's tough to be sure.

Tomorrow will be another unseasonably mild day. Much of the region could approach or reach 70°. Unseasonable warmth will continue into the first week of November. Dry conditions will likely persist until late next week. The ENSO Region 1+2 anomaly was +5.2°C and the Region 3.4 anomaly was +3.4°C for the week centered around October 14. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +5.08°C and the ENSO Region 3.4 anomaly has averaged +3.22°C. ENSO Region 3.4 breaks the all-time record most recently set in the prior week. The ongoing strong El Niño, will continue to strengthen through the mid-fall. The SOI was +10.31 yesterday. The preliminary Arctic Oscillation (AO) was +0.842 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal October (1991-2020 normal). October will likely finish with a mean temperature near 59.2° (1.3° above normal). Supplemental Information: The projected mean would be 2.3° above the 1981-2010 normal monthly value.

Record warmth affected parts of the upper Midwest today. Some of that air will move across the region over the next few days. As a result, it will turn noticeably milder tomorrow. The temperature will warm into the middle and upper 60s for the remainder of the work week. Much of the region could approach or reach 70° on Friday. Unseasonable warmth will continue into the start of November. Dry conditions will likely persist through next week. The ENSO Region 1+2 anomaly was +5.2°C and the Region 3.4 anomaly was +3.4°C for the week centered around October 14. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +5.08°C and the ENSO Region 3.4 anomaly has averaged +3.22°C. ENSO Region 3.4 breaks the all-time record most recently set in the prior week. The ongoing strong El Niño, will continue to strengthen through the mid-fall. The SOI was +10.31 today. The preliminary Arctic Oscillation (AO) was +1.219 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal October (1991-2020 normal). October will likely finish with a mean temperature near 59.2° (1.3° above normal). Supplemental Information: The projected mean would be 2.3° above the 1981-2010 normal monthly value.

One. The bottom right photo. There appears to be a contrail in that photo.

Cirrus, cirrocumulus, altocumulus clouds early this afternoon.

The latest NBM remains very mild for the start of November. Uncertainty increases at the end of the run.

Tomorrow will be another fair day. Highs will top out in the lower 60s across much of the region. Afterward, temperatures will warm into the middle and upper 60s for the remainder of the work week. Much of the region could approach or reach 70° on Friday. Unseasonable warmth will continue into the start of November. Dry conditions will likely persist through next week. The ENSO Region 1+2 anomaly was +5.2°C and the Region 3.4 anomaly was +3.4°C for the week centered around October 14. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +5.08°C and the ENSO Region 3.4 anomaly has averaged +3.22°C. ENSO Region 3.4 breaks the all-time record most recently set in the prior week. The ongoing strong El Niño, will continue to strengthen through the mid-fall. The SOI was +12.57 today. The preliminary Arctic Oscillation (AO) was +1.303 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 99% probability that New York City will have a warmer than normal October (1991-2020 normal). October will likely finish with a mean temperature near 59.4° (1.5° above normal). Supplemental Information: The projected mean would be 2.5° above the 1981-2010 normal monthly value.

The most recent NBM cycles have grown slightly cooler for the start of November. Nevertheless, readings remain well above average.

The AIFS ensembles are particularly warm for the first week of November. The regular ECMWF ensembles are still warm (highs in the 60s), but cooler than their AI counterparts. The extended range of the NBM is also closer to the regular ECMWF ensembles. Both sets of ECMWF ensembles have high spreads (uncertainty), especially after November 3. However, the uncertainty concerns the magnitude of warmth, not whether it will be warmer than normal. The idea of a warmer than normal start to November has been a recurrent theme on the guidance. The most recent ECMWF weekly guidance is below.