September 2013 Observations And Discussions

[Weathergun]

In this case, we may be seeing the blocking ridge too strong too our west or close by, for the ocean storm to affect our area. The block initially is keep the storm well to our south.

 

 

When the block starts breaking down and leaving, the storm has room to escape east, ahead of the next trough:

 

[bluewave]

In this case, we may be seeing the blocking ridge too strong our west or close by, for the ocean storm to affect our area.

 

The ocean storm is too far east to phase with the northern stream disturbance coming through the Lakes

and the block breaks down over the next 5 days. I guess this is par for the course in a La Nina

pattern with such a strong northern branch of the jet stream. The Euro ensembles have been

doing a better job recently than the OP. Last week we saw the ensembles correctly keep the 

southern low suppressed while the OP Euro was too far north initially.

 

 

[jm1220]

I would still look for some sort of significant weather event to impact the region in the next 1-2 weeks as the NAO transitions back to positive. Historically we've seen some of our biggest coastals with a transitioning NAO.

 

The trough that phased with Sandy was poised to blow up into a major Nor'easter anyway given the block to the east of it and strong energy diving down. It's certainly possible that there could be a significant weather event here, I'd like to see more of a block near Greenland and a depressed south jet with a strong enough S/W to spawn something more notable for here.

[Weathergun]

The ocean storm is too far east to phase with the northern stream disturbance coming through the Lakes

and the block breaks down over the next 5 days. I guess this is par for the course in a La Nina

pattern with such a strong northern branch of the jet stream. The Euro ensembles have been

doing a better job recently than the OP. Last week we saw the ensembles correctly keep the 

southern low suppressed while the OP Euro was too far north initially.

 

f120.gif

 

gblav_c300nv_h120.gif

The blocking ridge initially over the East Coast this weekend, keeps the ocean storm and northern stream disturbance separate. After it starts breaking down, both systems try to merge. But the flow is too fast.

[IsentropicLift]

This system was always based on blocking, which does initially force the system west, but it breaks down to quickly, at least on the GFS and allows it to escape east just in time.

[Isotherm]

Local color:




 

[Isotherm]

2010 - 2013, especially 10 and 11 were significantly warmer aug/sep.   Far too cool too early for my liking. 

 

 

Yeah I would've liked to get a bit more summer stuff in (cough cough, pool) but hopefully we get a longer season next year. Seemed short because May/June was coolish and rainy.

[Isotherm]

Seems that the cooler won out the rolller coaster depsite the guidance the week of the 9th saying otherwise similar to the end of July.  This past saturday was very late summer likebut that was an oasis in this early fall regime.

 

 

Initially it was looking like maybe some upper 70s for late this week / weekend but too much of an onshore flow for anything above 75. Pool's down to 66 now and getting ready for winter mode.

[Isotherm]

Now -1.3 temp departure on the month here.

[bluewave]

The blocking ridge initially over the East Coast this weekend, keeps the ocean storm and northern stream disturbance separate. After it starts breaking down, both systems try to merge. But the flow is too fast.

 

We really got lucky last February when the storm was able to blow up close enough to the area instead of out to sea in the 

fast Nina flow.

[IntenseBlizzard2014]

The 12Z GEFS has an elongated trough for the Eastern 2/3rds of the country and a nice Greenland Block+West Coast Ridge by October 7th. There is consistency showing. 

[jm1220]

We really got lucky last February when the storm was able to blow up close enough to the area instead of out to sea in the 

fast Nina flow.

Hopefully this winter we can see the flow slow down some and allow more opportunities for us to the south of New England. Even though the Feb event worked out by the skin of its teeth, other events which nailed eastern New England could have been a lot better for us with a little more blocking and the storm developing sooner. Too-late miller B's are the hallmark of any Nina around these parts.

[Guest Imperator]

12z Euro is far from the coast.

[SACRUS]

The 12Z GEFS has an elongated trough for the Eastern 2/3rds of the country and a nice Greenland Block+West Coast Ridge by October 7th. There is consistency showing. 

 

Models have been hinting for a deep trough amplification in that period.  Suspect 10/5 or 6 to about the 9th will be cool and potential storm.

[bluewave]

it looks like temperatures the first week of October should be close to average for this time of year with

a +EPO/-NAO/-AO pattern.

 

 

 

[doncat]

Now -1.3 temp departure on the month here.

Yeah similar departure here after today.

[forkyfork]

the blocking associated with sandy existed for at least a week prior

edit: better loop

[bluewave]

the blocking associated with sandy existed for at least a week prior

 

And had record 500 mb heights for October.

 

 

 

 

[SnoSki14]

All those reasons are why it's highly unlikely we will ever see anything close to Sandy in our lifetime, but you don't need Sandy-sequel storms to do major damage. We could get plenty of tropical threats in the future, probably along the lines of Irene although a few could be somewhat stronger. Both 1938 New England and Sandy are unlikely to occur anytime soon. However with strong blocking being a theme, we could see some strong coastal storms this year or others in the future. 

 

Kind of a shame we won't have a coastal this weekend, at least it would make the weather more interesting. I do see more interesting weather after the 1st week of October, the troughs get more powerful and we could get some stronger cold shots along with maybe some coastal development given the -NAO. The most likely change would be when it shifts from negative to positive if we have a disturbance to work with.

[jm1220]

And had record 500 mb heights for October.

 

BLOCK.png

 

Sandy_500anoms.jpg

That block was a huge contributor to the storm's intensity and track, no doubt. Not only did it cause the storm to stop heading NE and veer to almost WNW for a time, it also forced the massive trough to its west to collide right into it and make an even more Perfect Storm. With a weaker block, Sandy likely would have had much reduced impacts here.

[Isotherm]

The Sandy synoptic set-up was very rare, but that's not to say we're off the hook for damaging storms or hurricanes in the near future (coming decade). Hurricanes like the Donna, Carol, Gloria, etc. occurred in different large scale patterns, generally without the anomalous Newfoundland block. Most of them have a western ridge / eastern trough with some type of HP ridge in the Atlantic or NW Atlantic. However, not as anomalous as the Sandy block which forced the NW retrograde.

 

1944, Donna, Carol, Gloria

 

 

 

 

 

 

[bluewave]

That block was a huge contributor to the storm's intensity and track, no doubt. Not only did it cause the storm to stop heading NE and veer to almost WNW for a time, it also forced the massive trough to its west to collide right into it and make an even more Perfect Storm. With a weaker block, Sandy likely would have had much reduced impacts here.

 

Yeah, without such a strong block Sandy would have missed the phase and gone out to sea well east of the area.

The left turn into the Jersey Shore from the east was calculated to have a 714 year return period in a static climate.

 

http://www.ldeo.columbia.edu/~sobel/Papers/hall_sobel_grl_submitted.pdf

 

Abstract  Hurricane Sandy’s track crossed the New Jersey coastline at an angle closer to perpendicular than any previous hurricane in the historic record. This steep angle was one of many contributing factors to a surge-plus-tide peak-water level that  surpassed 4m in parts of New Jersey and New York. The lack of precedent in the historic record makes it difficult to estimate the rate of Sandy-like events using  solely historic landfalls. Here we use a stochastic model built on historical hurricane  data from the entire North Atlantic to generate a large sample of synthetic hurricane  tracks. From this synthetic set we calculate that under long-term average climate  conditions a hurricane of Sandy’s intensity or greater (category 1+) is expected to  make NJ landfall at least as close to perpendicular as Sandy at an average annual rate of only 0.0014 yr-1 (95% confidence range 0.0007 to 0.0023); i.e., a return period of 714 yr (95% confidence range 1429 to 435). Thus, either Sandy was an exceedingly rare storm, or our assumption of long-term average climate conditions  is erroneous, and Sandy’s track was made more likely by climate change in a way that is yet to be fully determined. 

[SnoSki14]

Given the ridging and blocking pattern expected for possibly 10+ days, one could argue it wouldn't be a bad setup for getting tropical systems up here, but since this year can barely produce anything then we are off the hook. 

 

It looks really warm to start October, I think we could be looking at some 80s around here. Certainly don't mind if it's warm now, I'd rather save the cold up for when it matters.

[Snow_Miser]

Given the ridging and blocking pattern expected for possibly 10+ days, one could argue it wouldn't be a bad setup for getting tropical systems up here, but since this year can barely produce anything then we are off the hook. 

 

It looks really warm to start October, I think we could be looking at some 80s around here. Certainly don't mind if it's warm now, I'd rather save the cold up for when it matters.

 

The Euro 2 Meter temperature maps do show a couple days that eclipse 80 in the medium range, so it does seem to be possible that we see a late gasp of 80 degree temperatures.

 

There is a huge signal for an amplifying trough in early October though on the GEFS. Every single member has some sort of negative height anomalies in the eastern part of the country. This would help to eliminate some of the positive anomalies to start October.

 

[winterwarlock]

I guess it will be delayed but not denied with the 80 degree temps next week....and while I like it hot, the fact that everyday is sunny and at least 70 means Im still wearing shorts and short sleeves and to me that's awesome. Love that the nasty rain and clouds have stayed away and so despite my disappointment with the temperatures I cannot argue too much with beautiful weather like this

[MJO812]

I guess it will be delayed but not denied with the 80 degree temps next week....and while I like it hot, the fact that everyday is sunny and at least 70 means Im still wearing shorts and short sleeves and to me that's awesome. Love that the nasty rain and clouds have stayed away and so despite my disappointment with the temperatures I cannot argue too much with beautiful weather like this

 

I'm done wearing shorts. I have been wearing pants for the past two weeks.

[SACRUS]

I guess it will be delayed but not denied with the 80 degree temps next week....and while I like it hot, the fact that everyday is sunny and at least 70 means Im still wearing shorts and short sleeves and to me that's awesome. Love that the nasty rain and clouds have stayed away and so despite my disappointment with the temperatures I cannot argue too much with beautiful weather like this

 

It has been very nice out.  Looks like the best shot at 80 would be tue/wed (10/1 -2) but im still uncertain we'll get that warm yet.

[Isotherm]

46F this morning for my 14th morning in the 40s this month. I think this is the most 40s that I can remember experiencing for the month of September. Impressive number considering my average low hasn't gone under 50 yet.

[uncle W]

It has been very nice out.  Looks like the best shot at 80 would be tue/wed (10/1 -2) but im still uncertain we'll get that warm yet.

long term average max for October is 79 and 80 since 1980...average long term minimum is 37...I expect at least one 80 degree day for the high and at least one day in the upper 30's for the low...probably around mid month for the cold and early in the month for the warmth...all in all I expect a cooler than average October...analogs 1964 and 1981...

[SACRUS]

46F this morning for my 14th morning in the 40s this month. I think this is the most 40s that I can remember experiencing for the month of September. Impressive number considering my average low hasn't gone under 50 yet.

 

Wow - I havent counted but that is impressive.  Dryness looks to continue.