Summer analogs 2011

[BethesdaWX]

The high-latitude autumn snow cover is theorized to affect Rossby waves and thus the amplitude of the jet stream in the arctic, hence the -AO/-NAO. As you say, the correlation is small and certainly does not explain this year's extreme -NAO block in December when a colder than normal stratosphere due to the +QBO/Niña should have produced lower heights over the high latitudes. I think a lot of this year's blocking pattern was due to the Atlantic SST and geomagnetic activity associated with the solar minimum. Although the solar minimum in theory should further cool the stratosphere and compound the QBO/Niña, long periods of solar minimum in the past have locked in a -NAO pattern, such as during the Maunder Minimum in the 17th century...it may have to do with the fact that the natural downward variation in the NAO ascribed to the decadal cycle becomes "stuck" in a jet stream that is slower and less prone to fluctuation when we have a solar minimum. We're certainly in the negative NAO decadal cycle, and I think the tri-pole pattern in the Atlantic is exacerbating this...the Newfoundland cold pool (50/50 LOW) is well connected to the Greenland block, especially during the winter. We still see the warm-cold-warm pattern dominating in the Atlantic, despite that the NAO has recovered.

So what does this all mean for the summer? Well, unlike last year, I'm expecting a more +NAO summer...the vortex over Baffin Island has become dominant, probably enhanced by the strong Aleutian ridge which extends all the way back into Siberia, a result of the Niña-like tropical convection patterns. This amplified Aleutian ridge really seems to be cementing the Northern Canada vortex into place, limiting the amount of blocking we're seeing on the Atlantic side. With the Niña holding its ground, I expect this pattern to continue...the combination of the -EPO and this cold pool over Arctic Canada should give the northern tier some cold shots during the summertime, meaning that I'm preliminarily forecasting a below-normal summer for the High Plains/Upper Midwest, and potentially into Northern New England. Given that I see the La Niña potentially restrengthening later on, especially given the inability of the MJO to move into the Niño like Phase 7/8, I expect the Bermuda ridge to be prominent, with the strongest warm anomalies over the drought-stricken areas of the Southern Plains. Although the analogs show the S Plains being hot during April with a fading La Niña, and then cooling off during the summer into below normal values, I'm not sure this is going to happen this year. With the dearth of moisture in the far South and very wet/stormy conditions in the Ohio Valley and Northern Plains, I'm thinking this could augment the amplified ridge/trough configuration we're seeing this April. I expect a hotter and drier summer than normal for the Southwest, Southern Plains, and far Southeast with more normal temperatures as you venture further north, and an active severe weather season continuing unless El Niño somehow gets a foothold.

Agree completely, I just don't think you can say snowcover is a "driver", but more of an "enhancer" to a -AO already in place... although I'm no Met and have no proffessional experience.

Also, do the 11yr Intra-cycle Solar Minimums always correlate with increased Nina conditions? Because I haven't found evidence that they do, neither the AO. The AP-index index correlates very well to the AO/NAO, and isn't really impacted by the SC directly in 11yr fluxes as the sunspot number is, but the NAO/AO tend to follow it.

So the fact that the Magnetic Activity/Flux of the Sun has dipped very low in this minimum, is a sign that a significant Solar Minimum might be on the way, since it seems past solar may have seen the Dip in the Intracycle before following a weaker SC(s) afterwards.

[nzucker]

Agree completely, I just don't think you can say snowcover is a "driver", but more of an "enhancer" to a -AO already in place... although I'm no Met and have no proffessional experience.

Also, do the 11yr Intra-cycle Solar Minimums always correlate with increased Nina conditions? Because I haven't found evidence that they do, neither the AO. The AP-index index correlates very well to the AO/NAO, and isn't really impacted by the SC directly in 11yr fluxes as the sunspot number is, but the NAO/AO tend to follow it.

So the fact that the Magnetic Activity/Flux of the Sun has dipped very low in this minimum, is a sign that a significant Solar Minimum might be on the way, since it seems past solar may have seen the Dip in the Intracycle before following a weaker SC(s) afterwards.

I don't think it's as simple as low solar=La Niña; otherwise we would not have seen so many cold ENSO states during the 50s when solar activity was very high. Theodore Landscheidt writes, "The 11-year sunspot cycle meets these conditions of external forcing. Yet climatologists who exclusively consider the change in the sun’s irradiance solely look at maxima and minima of the sunspot cycle. It is easy to see that these extrema show no consistent and sufficiently strong correlation with the El Nino phenomenon."

Landscheidt proposes that there is a smaller, but equally variable (like the 11-year cycle, it can be longer or shorter depending on solar conditions), 7.15 year magnetic solar cycle within the large cycles, and this is a strong determinant of ENSO. In his view, it is not necessarily periods of intense solar flares/coronal mass ejections (CMEs) that regulate ENSO, but rather the length of different types of solar cycles which are all based on the magnetic activity of the Sun. When the 7.15 year cycle has a normalized value of approximately 0.0, 0.236, 0.382, 0.618, and 0.764 relative to the normal cycle length, there is an increased likelihood historically of an El Niño. Interestingly, the 11-year solar cycle also tends to divide into parts equivalent to some of these values, with the ascending phase generally being around 38.2% of the cycle length, and the descending phase being around 61.8% of the cycle length, something Landscheidt refers to as the "Golden Section."

http://www.john-daly...so/sun-enso.htm

[BethesdaWX]

I don't think it's as simple as low solar=La Niña; otherwise we would not have seen so many cold ENSO states during the 50s when solar activity was very high. Theodore Landscheidt writes, "The 11-year sunspot cycle meets these conditions of external forcing. Yet climatologists who exclusively consider the change in the sun’s irradiance solely look at maxima and minima of the sunspot cycle. It is easy to see that these extrema show no consistent and sufficiently strong correlation with the El Nino phenomenon."

Landscheidt proposes that there is a smaller, but equally variable (like the 11-year cycle, it can be longer or shorter depending on solar conditions), 7.15 year magnetic solar cycle within the large cycles, and this is a strong determinant of ENSO. In his view, it is not necessarily periods of intense solar flares/coronal mass ejections (CMEs) that regulate ENSO, but rather the length of different types of solar cycles which are all based on the magnetic activity of the Sun. When the 7.15 year cycle has a normalized value of approximately 0.0, 0.236, 0.382, 0.618, and 0.764 relative to the normal cycle length, there is an increased likelihood historically of an El Niño. Interestingly, the 11-year solar cycle also tends to divide into parts equivalent to some of these values, with the ascending phase generally being around 38.2% of the cycle length, and the descending phase being around 61.8% of the cycle length, something Landscheidt refers to as the "Golden Section."

http://www.john-daly...so/sun-enso.htm

Of course, I never suggested otherwise. But yeah def, that is very interesting, I've always wondered if SC Length (in between intra-inter) played a role in the Earth's weather/climate system regarding H/LLB & ENSO, on Magnetic activity itself. The 1950's thru 1970's were in the -PDO phase, so La Nina would be expected then anyway, so I don't think solar is a "driver" of ENSO, or at least not directly.

However attributing the Sun to everything seems kind of awkward, Unlike ENSO, the PDO seems to be related to Currents Processing in the oceans "turning", in a sense, as in, driven by the oceans themselves to an extent, while ENSO is more systematically driven, otherwise ENSO would have to act more independantly from the PDO, but yet we see it oscillate in frequency over 30yr spans, and this wouldn't happen unless the ocean has the power on the frequency of ENSO.

[Supercane]

I don't think it's as simple as low solar=La Niña; otherwise we would not have seen so many cold ENSO states during the 50s when solar activity was very high. Theodore Landscheidt writes, "The 11-year sunspot cycle meets these conditions of external forcing. Yet climatologists who exclusively consider the change in the sun’s irradiance solely look at maxima and minima of the sunspot cycle. It is easy to see that these extrema show no consistent and sufficiently strong correlation with the El Nino phenomenon."

Landscheidt proposes that there is a smaller, but equally variable (like the 11-year cycle, it can be longer or shorter depending on solar conditions), 7.15 year magnetic solar cycle within the large cycles, and this is a strong determinant of ENSO. In his view, it is not necessarily periods of intense solar flares/coronal mass ejections (CMEs) that regulate ENSO, but rather the length of different types of solar cycles which are all based on the magnetic activity of the Sun. When the 7.15 year cycle has a normalized value of approximately 0.0, 0.236, 0.382, 0.618, and 0.764 relative to the normal cycle length, there is an increased likelihood historically of an El Niño. Interestingly, the 11-year solar cycle also tends to divide into parts equivalent to some of these values, with the ascending phase generally being around 38.2% of the cycle length, and the descending phase being around 61.8% of the cycle length, something Landscheidt refers to as the "Golden Section."

http://www.john-daly...so/sun-enso.htm

I've noticed both El Niños and La Niñas tend to hold on longer when solar activity is high/rising, and tend to dissipate quicker when solar activity is low/falling. I'm not sure how this would be the case though, or if there has been any extensive research on such a correlation. Maybe increased galactic cosmic rays of the solar minimum = increased cloud heights in the tropics = less stable tropics = less stable ENSO in general?

[nzucker]

Of course, I never suggested otherwise. But yeah def, that is very interesting, I've always wondered if SC Length (in between intra-inter) played a role in the Earth's weather/climate system regarding H/LLB & ENSO, on Magnetic activity itself. The 1950's thru 1970's were in the -PDO phase, so La Nina would be expected then anyway, so I don't think solar is a "driver" of ENSO, or at least not directly.

However attributing the Sun to everything seems kind of awkward, Unlike ENSO, the PDO seems to be related to Currents Processing in the oceans "turning", in a sense, as in, driven by the oceans themselves to an extent, while ENSO is more systematically driven, otherwise ENSO would have to act more independantly from the PDO, but yet we see it oscillate in frequency over 30yr spans, and this wouldn't happen unless the ocean has the power on the frequency of ENSO.

The sun must be somewhat of a driver on ENSO, as Landscheidt was able to predict the moderate El Niño of 02-03 using just solar variables, over 2 years out. He also successfully predicted another Niño in this fashion though not sure which one. Clearly, the background +PDO state with outstanding warmth in the Gulf of Alaska was an impetus for these recent warm ENSO events, but their specific formation was probably due to some tweaking of the geomagnetic activity or cycle length. The problem with the solar theory is that there are so many cycles proposed: 7-year cycle, 11-year cycle, 36 years, 178 years, etc...at least according to Landscheidt, so it becomes a bit confusing. Some believe that we've arrived at the intersection of the minimum of each of these cycles, leading the way to a Grand Minimum; we'll see about that. It is amazing how the structure of the SST anomalies have shifted with the PDO/solar changes in the last decade...

Here was the end of the 2002-03 El Niño that led to a multi-year warm event...almost all the anomalies are reversed from now in the South Atlantic and North Pacific, although we still have the signature of a -NAO regime:

Here is the current map, even though the La Niña has weakened, the "horseshoe" -PDO configuration seems to be strengthening with new cold anomalies showing up near Baja California:

You can see that the MJO seems to be having a tough time making the full push into supporting a Kelvin Wave/WWB:

Trades expected through 4/27, dying off of the westerly anomalies:

[skierinvermont]

I'm still betting on warmer than normal for the SE and Southern Plains, which goes against dying Niña climo. I think the dry soil is going to make for quite a ridge there, and we've already seen a bit of this pattern in March and April with the cut-off for warmer than normal temperatures being around RIC/RDU.

1) The analogs I posted which show below average temperatures for the most of the eastern 2/3s of the country also featured drought conditions and below average precipitation in the preceding winter/early spring. Why didn't the drought conditions in the south those years prevent the cold summer but suddenly it will prevent it this year?

2) wxwatcher is correct that soil moisture's effect is largely confined to the near surface layer and does not force large scale troughs and ridges. Vawxman agreed (which should be good enough for any of us mere mortals) and I assume he made this statement based on his knowledge of atmospheric physics and the peer-reviewed literature on the subject such as the following:

"the effect of the soil moisture anomalies, however, is mostly confined to the near-surface climate variability with little impact on the dynamic variability in the atmosphere, "

http://www.agu.org/j...8JD200010.shtml

"Eat crow." I think you owe someone an apology.

[BethesdaWX]

The sun must be somewhat of a driver on ENSO, as Landscheidt was able to predict the moderate El Niño of 02-03 using just solar variables, over 2 years out. He also successfully predicted another Niño in this fashion though not sure which one. Clearly, the background +PDO state with outstanding warmth in the Gulf of Alaska was an impetus for these recent warm ENSO events, but their specific formation was probably due to some tweaking of the geomagnetic activity or cycle length. The problem with the solar theory is that there are so many cycles proposed: 7-year cycle, 11-year cycle, 36 years, 178 years, etc...at least according to Landscheidt, so it becomes a bit confusing. Some believe that we've arrived at the intersection of the minimum of each of these cycles, leading the way to a Grand Minimum; we'll see about that. It is amazing how the structure of the SST anomalies have shifted with the PDO/solar changes in the last decade...

Here was the end of the 2002-03 El Niño that led to a multi-year warm event...almost all the anomalies are reversed from now in the South Atlantic and North Pacific, although we still have the signature of a -NAO regime:

Here is the current map, even though the La Niña has weakened, the "horseshoe" -PDO configuration seems to be strengthening with new cold anomalies showing up near Baja California:

You can see that the MJO seems to be having a tough time making the full push into supporting a Kelvin Wave/WWB:

Trades expected through 4/27, dying off of the westerly anomalies:

Agree completely, when I said indirectly, I meant Solar's influence on the Atmosphere is what could Influence ENSO, not the Sun itself (crazy me), and that Mechanism Hasn't been found yet... possibly? I'm not sure I can buy into Landscheits predictions completely, because it could be just chance. The issue seems to be that there are so many aspects to the Sun, and the climate system is just so freakin complicated, that finding hard evidence of anything becomes somewhat impossible regarding effect to ENSO.

But another unanswered question, can the climate system influence itself through its own Mechanisms, or Is the Sun required to Drive these Mechanisms in some way? After all, the only reason the Climate system is Technically "alive and running" is due to the Sun & its energy, but yet, could it be like Charging a Battery, and processes within the Earth's own Climate system are interconnecting mechanisms that don't rely on the Sun to Function?

All this is legit stuff that cannot be figured out at this point, which is why I question Landscheit to an extent.

[nzucker]

1) The analogs I posted which show below average temperatures for the most of the eastern 2/3s of the country also featured drought conditions and below average precipitation in the preceding winter/early spring. Why didn't the drought conditions in the south those years prevent the cold summer but suddenly it will prevent it this year?

2) wxwatcher is correct that soil moisture's effect is largely confined to the near surface layer and does not force large scale troughs and ridges. Vawxman agreed (which should be good enough for any of us mere mortals) and I assume he made this statement based on his knowledge of atmospheric physics and the peer-reviewed literature on the subject such as the following:

"the effect of the soil moisture anomalies, however, is mostly confined to the near-surface climate variability with little impact on the dynamic variability in the atmosphere, "

http://www.agu.org/j...8JD200010.shtml

"Eat crow." I think you owe someone an apology.

Why do I owe him an apology? All I said was that he initially doubted my claim, quite vociferously, that high fall snow cover could lead to a -NAO/-AO...he was forced to retract that, hence the colloquial expression "eat crow" after I offered a few articles and analog years like 76-77 and 09-10 where high NH snow cover helped bring about high-latitude blocking during the winter. I never said he should "eat crow" about this matter but just that the old saying "drought begets drought" certainly has many believers in the meteorological community.

Why are you getting pissy again?

BTW I will respond to the rest of your questions regarding my summer ideas in a second, but I just wanted to say that I wasn't claiming he should "eat crow" about soil moisture, just that it's silly not to consider it when it has much support from both folklore and energy mets. It was certainly one of the reasons I doubted Chuck last summer when he had big plus anomalies over the Northern Plains/Northern Rockies where I was living and working for the month of July, and I certainly ended up being right that the cool, wet pattern would continue. We had such an astounding excess of soil moisture, and were in such a consistently rainy pattern, that it was hard to imagine we'd torch.

[skierinvermont]

Why do I owe him an apology? All I said was that he initially doubted my claim, quite vociferously, that high fall snow cover could lead to a -NAO/-AO...he was forced to retract that, hence the colloquial expression "eat crow" after I offered a few articles and analog years like 76-77 and 09-10 where high NH snow cover helped bring about high-latitude blocking during the winter. I never said he should "eat crow" about this matter but just that the old saying "drought begets drought" certainly has many believers in the meteorological community.

Why are you getting pissy again?

I'm not getting pissy I just don't see why you need to tell people how much crow they have eaten in the past, especially when you're wrong (as Vawxman and numerous peer-reviewed studies agree).

[BethesdaWX]

I'm not getting pissy I just don't see why you need to tell people how much crow they have eaten in the past, especially when you're wrong (as Vawxman and numerous peer-reviewed studies agree).

I'm sorry what was he wrong about? I'm having trouble figuring that out, Its My fault I cannot understand

Or is it what he "could be" wrong about?

[skierinvermont]

I'm sorry what was he wrong about? I'm having trouble figuring that out, Its My fault I cannot understand

Or is it what he "could be" wrong about?

He claimed that drought conditions in the SE U.S. would create a ridge and got pretty aggressive towards wxwatcher for suggesting otherwise. However as VaWxman (whose opinion is worth 100X any of ours) and numerous peer-reviewed studies conclude, drought conditions influence mostly just the lowest levels of the atmosphere and does not force ridges or troughs.

[BethesdaWX]

He claimed that drought conditions in the SE U.S. would create a ridge and got pretty aggressive towards wxwatcher for suggesting otherwise. However as VaWxman (whose opinion is worth 100X any of ours) and numerous peer-reviewed studies conclude, drought conditions influence mostly just the lowest levels of the atmosphere and does not force ridges or troughs.

Oh ok, I thought he said it would influence the potential for a hotter summer at the surface, not necessarily cause one directly at the upper levels.

Of course ruling out a Tropical System, which I'd think will save their azzez.

[nzucker]

I'm not getting pissy I just don't see why you need to tell people how much crow they have eaten in the past, especially when you're wrong (as Vawxman and numerous peer-reviewed studies agree).

I just think Sam has a tendency to downplay surface features in forecasting since he likes to use the more complex stuff like the QBO etc for long-range forecasting. When I was suggesting that Winter 10-11 might feature a more -NAO/-AO than expected due to the high snow cover anomaly that was starting to develop in the upper latitudes of the Northern Hemisphere, he was quick to dismiss it in a somewhat condescending manner as if I were some simpleton who didn't have the orange tag next to their name (whatever that BS means anyway)....it turned out plenty of studies backed me up well, as did past analogs. Now, I'm not saying Sam is definitely incorrect about soil moisture being uncorrelated to 500mb heights, but he was once again very dismissive of my claim, especially when VAWXMAN came to his rescue, as if that were somehow an absolute confirmation of what he was thinking. I tend to believe summertime forecasting, as opposed to the winter, is more about short-term variability in soil moisture, sea surface temperatures, wind patterns etc...not to say that the big stuff isn't relevant, but large-scale factors like the NAO, QBO, AO start to break down a bit as opposed to the strong correlations we see during the cold season.

There is clearly a disagreement about the effect of soil moisture on ridging. Here is what DT has to say:

"Let's take a look how this works. It is a well known and proven weather "saying" that drought begets drought and a wet pattern be gets more wet patterns. The reason that these "sayings" are valid hass to do with something called positive feedback. Large areas of dry grounds give off excessive Heat and lower than Normal Humidity especially during the hot Summer months. This additional heat feeds into the atmosphere and reinforces a ridge which might be in place at the jet stream level. Likewise large areas of really wet ground often mean that the soils are colder than normal and the excessive low level humidity from the wet soils feedback into the atmospere in such a way as to keep the mean trough position located over a general area."

http://1664596.sites.myregisteredsite.com/seasonalforcst/summer10/SUMER2010.htm

Here is an interesting study about the Summer 1980 heat wave:

Numerical experiments related to the summer 1980 U.S. heat wave

WOLFSON, N | ATLAS, R | SUD, Y C

Monthly Weather Review. Vol. 115, pp. 1345-1357. July 1987

The NASA Goddard Laboratory for Atmospheres fourth-order GCM was used in a series of medium-range numerical forecast experiments in order to improve understanding of the severe summer 1980 heat wave over the U.S. The results show that the derived soil moisture anomalies in the summer of 1980 contributed positively to the model's simulation of the heat wave maintenance, and suggest that once a region of reduced soil moisture is established, it tends to persist and maintain warmer and drier conditions. The lower soil moisture values resulted in reduced evaporation, higher ground temperatures, increased sensible heat flux from ground to air, higher surface air temperature, lower sea-level pressure, and higher 500-mb height. The effects of North Pacific sea-surface-temperature anomalies were mostly opposite to those of the soil-moisture anomalies: enhanced northerly flow of cooler drier air, increased evaporation, lower ground and air temperature, higher sea level pressure, and lower 500 mb heights over the Great Plains...

http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=TRD&recid=A8750609AH&q=soil+moisture+500mb+anomalies&uid=790643084&setcookie=yes

[skierinvermont]

Well DT is wrong. The study you are citing is 20+ years old and uses the 20+ year old GISS climate model (ironically the same model you bash continually as being a complete failure in the climate change forum). I have read a half a dozen newer studies using newer models and better methods that disagree.

[BethesdaWX]

Well DT is wrong.

What a surprise

[nzucker]

He claimed that drought conditions in the SE U.S. would create a ridge and got pretty aggressive towards wxwatcher for suggesting otherwise. However as VaWxman (whose opinion is worth 100X any of ours) and numerous peer-reviewed studies conclude, drought conditions influence mostly just the lowest levels of the atmosphere and does not force ridges or troughs.

How did I get aggressive towards him? I just said that he had been incorrect about surface conditions being a non-factor in the past, with regards to snow cover...he was quite aggressive towards me on that point of debate, to the contrary.

It's clear that you just love getting me riled up, I guess when there's nothing else to do at 140am it's in good fun.

[skierinvermont]

How did I get aggressive towards him?

Fine, every time you try and forecast something on here I'm going to remind you how much crow you've eaten on in the past. Great idea!

Whatever. I'm not going to continue to derail this thread any more. If you want to remind people how much crow they've eaten go right ahead. I won't say a word.

The fact remains, soil moisture's effect is primarily the lowest levels of the atmosphere not the upper. And the dozen or so Nina analogs I have given also showed drought conditions in March but ended up with below average temperatures in summer, so obviously the predictive power even at the surface is weak at best with a 3+ month lead time.

I think this is because the correlation even at the surface becomes much weaker at lag times of 3+ months.

[nzucker]

Although this is by no means conclusive, using soil moisture as a predictor for summer temperatures would have worked EXTREMELY well in forecasting Summer 2008, 2009, and 2010. Obviously, there are other factors in play, and this is only one piece of the puzzle. Anyway, I am going to post the first map for each year showing the Palmer Drought Severity Index in May, and then the second map is the temperature anomaly for that following summer (June to August).

2008:

May Palmer Index:

Summer Anomalies:

2009:

May Palmer Index:

Summer Anomalies:

2010:

May Palmer Index:

Summer Anomalies:

[skierinvermont]

Looks good in 08 and 09.. but very poor in 2010 probably more wrong than right (negative forecast skill). Lot's of areas blue that ended up toasty and vice versa in 2010. Soil moisture for the eastern 2/3s of the U.S. in may 2010 was around average overall.. the summer was a total torch. But it was good in 08 and 09.

But as I said, that's for May whereas we're only halfway through april and I've only seen data for March. The correlation is much better for a 1-2 month lead than a 3+ month lead.

[nzucker]

Fine, every time you try and forecast something on here I'm going to remind you how much crow you've eaten on in the past. Great idea!

Whatever. I'm not going to continue to derail this thread any more. If you want to remind people how much crow they've eaten go right ahead. I won't say a word.

The fact remains, soil moisture's effect is primarily the lowest levels of the atmosphere not the upper. And the dozen or so Nina analogs I have given also showed drought conditions in March but ended up with below average temperatures in summer, so obviously the predictive power even at the surface is weak at best with a 3+ month lead time.

I think this is because the correlation even at the surface becomes much weaker at lag times of 3+ months.

I don't understand...the only reason I'd said something is because he's shown a tendency before to ignore surface conditions in favor of atmospheric variables when forecasting; I was trying to note that there was a trend, and I find it instructive to take a look at the surface, too. The point wasn't just to remind him of some random mistake he'd made in the past, it was to criticize/debate a forecasting tact of his which I feel sometimes leads to a less than complete picture of the season's patterns. Why do you always do this to me, Andrew? It just seems you purposefully try to start arguments on here instead of just discussing the facts...perhaps "eat crow" wasn't the nicest way to put it, but I don't see why you have to butt in on his behalf. And of course, you just completely assume I'm wrong without accounting for the fact that many other meteorologists seem to be using soil moisture prominently as a tool for forecasting the summer, and some energy meteorologists and studies do find a link between extreme drought/wetness and tendencies in the jet stream. Maybe you should just be patient while I unroll and develop my argument instead of just coming to a preconceived conclusion of "I'm wrong" and then not listening to anything else I say seriously, either. This is what I've asked you before, try to keep your mind open throughout a discussion instead of already having a decision made and then just blocking everything out that disagrees. This is why I don't like to debate with you, because you get glued to a position and then just basically knock everything else down, before you've heard all the argument unroll.

I haven't even gotten into half of why I feel Summer 2011 may be a hotter than expected one, and yet you're already in "You're wrong" mode. It's tiresome..

[skierinvermont]

I don't understand...the only reason I'd said something is because he's shown a tendency before to ignore surface conditions in favor of atmospheric variables when forecasting; I was trying to note that there was a trend, and I find it instructive to take a look at the surface, too. The point wasn't just to remind him of some random mistake he'd made in the past, it was to criticize/debate a forecasting tact of his which I feel sometimes leads to a less than complete picture of the season's patterns. Why do you always do this to me, Andrew? It just seems you purposefully try to start arguments on here instead of just discussing the facts...perhaps "eat crow" wasn't the nicest way to put it, but I don't see why you have to butt in on his behalf. And of course, you just completely assume I'm wrong without accounting for the fact that many other meteorologists seem to be using soil moisture prominently as a tool for forecasting the summer, and some energy meteorologists and studies do find a link between extreme drought/wetness and tendencies in the jet stream. Maybe you should just be patient while I unroll and develop my argument instead of just coming to a preconceived conclusion of "I'm wrong" and then not listening to anything else I say seriously, either. This is what I've asked you before, try to keep your mind open throughout a discussion instead of already having a decision made and then just blocking everything out that disagrees. This is why I don't like to debate with you, because you get glued to a position and then just basically knock everything else down, before you've heard all the argument unroll.

I haven't even gotten into half of why I feel Summer 2011 may be a hotter than expected one, and yet you're already in "You're wrong" mode. It's tiresome..

I'm not saying your forecast is wrong at all. I am simply making two observations 1) soil moisture predicts near surface conditions not ridges and troughs as you suggested 2) the correlation becomes much stronger by May than it is in March. I have no idea what to expect for Summer 2010 and am open to well reasoned thoughts beyond the ENSO climo I have posted. I am making two very specific statements and yet somehow you confuse this as an attack upon your entire forecast. So instead of responding to my two very specific objections you get defensive and spew a bunch of personal criticisms just like you did to Sam. Obviously you have no interest in the actual facts and are in this for ego, so I'm out. Have fun.

There are better ways of saying someone's forecasting tact is wrong than saying they eat crow. And he also was not saying that soil moisture doesn't matter. In fact he specifically said it DOES matter. Just not in the way you were incorrectly applying it.

[nzucker]

Looks good in 08 and 09.. but very poor in 2010 probably more wrong than right (negative forecast skill). Lot's of areas blue that ended up toasty and vice versa in 2010. Soil moisture for the eastern 2/3s of the U.S. in may 2010 was around average overall.. the summer was a total torch. But it was good in 08 and 09.

But as I said, that's for May whereas we're only halfway through april and I've only seen data for March. The correlation is much better for a 1-2 month lead than a 3+ month lead.

Well 2010 had an overwhelming ENSO change that was obviously going to drive the summer pattern regardless of soil moisture...in general, though, the Southeast/Mid-Atlantic was a bit drier and that's where more of the warm anomalies developed...it got wetter as you headed west of the Mississippi relative to average, and those areas stayed out of the big warmth and even finished with some cold anomalies. Also, precipitation was way above average for Nebraska (especially)/Montana/North Dakota in April/May/June and the coldest part of the summer was June and July; you lose a bit of the picture because August warmed up as the soil moisture became less anomalous. In those areas, it's probably more important early in the summer because they are expected to get most of their precipitation in spring due to the seasonal migration of the jet/storm track, so the influence becomes lesser by August, which did indeed have a warming trend. Obviously, other factors were also important such as the block over AK releasing Canadian air that got trapped between that ridge and the ridge over Greenland, leading to a small area of below normal heights in MT/Alberta...

I think one thing you have to be careful of in studies of soil moisture vs. 500mb pattern is the fact that I'm specifically highlighting large regions of EXTREMELY ANOMALOUS conditions, like the historic/exceptional drought underway in the Southern Plains today. You aren't going to find many useful correlations when you have a checkerboard landscape of slightly dry/wet areas, but it is more of a forecasting tool when you do see the emergence of an exceptional area of aridity or moisture, and that was clearly the case with the Northern Rockies in early Summer 2010 and presumably the Southern Plains in Summer 2011. Given that the jet stream is such a large-scale feature, you need a very powerful anomaly that stretches over hundreds of miles to make a difference in the position of a ridge or a trough.

Also, you have to think about how different regions get their summertime precipitation.As the 1989 Delworth/Manabe paper "The Influence of Soil Wetness on Near-Surface Atmospheric Variability," you're going to have higher relative humidities in areas with soil wetness. This could be a key factor for the formation of thunderstorms, or the lack of thunderstorms, in a region like the Southern Plains; since Texas is largely out of the jet stream's storm track during the summer months, a lot of their moisture is going to come from convection, which depends on higher dewpoints to increase instability. With drier soils, and a large-scale ridge in place already capping the atmosphere with warm temperatures all the way up to 500mb, it's going to be increasingly harder to get rainfall...this is going to make the drought worse, and once again increase the temperatures. Obviously, the wild card is a tropical system, which conversely the SE ridge warming the Gulf is increasing the probability of, so there is always that to think about.

In terms of going against the ENSO analogs, it also seems that some of the hotter summers came when we moved back into a stronger Niña...I think this is a possibility given the lack of MJO activity towards Phase 7/8, the continued power of the -PDO, and the seeming tendency for more trade winds to be occurring now that we passed the opportunity for the main Kelvin Wave. Years that had a resurgence of Niña like 1955 and 1999 did have a warmer summer nationally...throw in a lack of blocking aside from a -EPO that won't influence places except for the Northern Tier, and I think the recipe for a toasty one is set:

I am aware my preliminary forecast looks exactly contrast to the post-Niña summers which has a cool South/Southeast and a warmer Northern Plains, but here it is:

[skierinvermont]

FYI soil moisture has been increasing across the SE. In March most of the southern half of the country had dryer than average soil. Basically KS, southern MO, TN, KY, VA and everywhere south of there. Now VA, TN, KY, northern GA and AL all have average to above average soil moisture. Other nearby areas which were very dry before are only slightly dry now, with the real dryness being confined to southern GA and SC, and then TX, OK, LA and southern AR.

And it looks like much of the south is going to receive some good rains this week with a couple storms progressing into the south.

So the dryness is on the retreat. Which is why soil moisture doesn't work as well with a 3+ month lead time.

[nzucker]

FYI soil moisture has been increasing across the SE. In March most of the southern half of the country had dryer than average soil. Basically KS, southern MO, TN, KY, VA and everywhere south of there. Now VA, TN, KY, northern GA and AL all have average to above average soil moisture. Other nearby areas which were very dry before are only slightly dry now, with the real dryness being confined to southern GA and SC, and then TX, OK, LA and southern AR.

And it looks like much of the south is going to receive some good rains this week with a couple storms progressing into the south.

So the dryness is on the retreat. Which is why soil moisture doesn't work as well with a 3+ month lead time.

All the severe weather has made its mark for sure. Although I wouldn't really say the dryness is on the retreat; perhaps in aerial coverage it is, but some places in TX/OK are experiencing a much worse drought now than they were a couple of months ago, with hundreds of thousands of acres of wildfires occurring in the last week in Central TX. In my final summer forecast, which I won't be releasing until mid-May and which will be much more substantiated than whatever BS I've spewed so far, I'm probably going to move the big ridge a bit further west to come more in line with HM's thoughts. I could see the real center of the heat being the Southern Plains into the Southwest, although I'm still not convinced the Southeast will go below normal as many of the Niña analogs suggest.

Also, this is typically a time of year when the Southeast can see big rainfalls due to these large-scale severe outbreaks when you have a Colorado low or Plains low forming and then tracking towards Chicago and either up the St. Lawrence Valley or towards James Bay. This is a very typical pattern for late March/April, especially in Niña years. However, you often see the storm track shift NW as we head into May and the jet retreats towards Canada, so then the warm sector ends up being much more arid as the Bermuda ridge becomes established. Many places such as Upstate SC have been in a ten-year long drought, so we'll see if this rainy pattern is a true sign of relief or just temporary. What happens in early May could influence my thoughts a lot in terms of the summer pattern since it's easy to make up on rainfall now whereas it becomes more difficult later if we start seeing above normal temperatures down there.

[VAwxman]

given the lack of MJO activity towards Phase 7/8

Stepping aside from the soil moisture argument for a bit...

I do not follow the part I quoted.

Obviously this doesn't mean you cannot get a resurgence of la nina, but the most surprising thing about the MJO has been that it has avoided the "typical" nina phases more than p7-p8, which is one reason the nina has taken a hit, along with climatology favoring weakening ENSO events in the spring.

[usedtobe]

Well 2010 had an overwhelming ENSO change that was obviously going to drive the summer pattern regardless of soil moisture...in general, though, the Southeast/Mid-Atlantic was a bit drier and that's where more of the warm anomalies developed...it got wetter as you headed west of the Mississippi relative to average, and those areas stayed out of the big warmth and even finished with some cold anomalies. Also, precipitation was way above average for Nebraska (especially)/Montana/North Dakota in April/May/June and the coldest part of the summer was June and July; you lose a bit of the picture because August warmed up as the soil moisture became less anomalous. In those areas, it's probably more important early in the summer because they are expected to get most of their precipitation in spring due to the seasonal migration of the jet/storm track, so the influence becomes lesser by August, which did indeed have a warming trend. Obviously, other factors were also important such as the block over AK releasing Canadian air that got trapped between that ridge and the ridge over Greenland, leading to a small area of below normal heights in MT/Alberta...

I think one thing you have to be careful of in studies of soil moisture vs. 500mb pattern is the fact that I'm specifically highlighting large regions of EXTREMELY ANOMALOUS conditions, like the historic/exceptional drought underway in the Southern Plains today. You aren't going to find many useful correlations when you have a checkerboard landscape of slightly dry/wet areas, but it is more of a forecasting tool when you do see the emergence of an exceptional area of aridity or moisture, and that was clearly the case with the Northern Rockies in early Summer 2010 and presumably the Southern Plains in Summer 2011. Given that the jet stream is such a large-scale feature, you need a very powerful anomaly that stretches over hundreds of miles to make a difference in the position of a ridge or a trough.

Also, you have to think about how different regions get their summertime precipitation.As the 1989 Delworth/Manabe paper "The Influence of Soil Wetness on Near-Surface Atmospheric Variability," you're going to have higher relative humidities in areas with soil wetness. This could be a key factor for the formation of thunderstorms, or the lack of thunderstorms, in a region like the Southern Plains; since Texas is largely out of the jet stream's storm track during the summer months, a lot of their moisture is going to come from convection, which depends on higher dewpoints to increase instability. With drier soils, and a large-scale ridge in place already capping the atmosphere with warm temperatures all the way up to 500mb, it's going to be increasingly harder to get rainfall...this is going to make the drought worse, and once again increase the temperatures. Obviously, the wild card is a tropical system, which conversely the SE ridge warming the Gulf is increasing the probability of, so there is always that to think about.

In terms of going against the ENSO analogs, it also seems that some of the hotter summers came when we moved back into a stronger Niña...I think this is a possibility given the lack of MJO activity towards Phase 7/8, the continued power of the -PDO, and the seeming tendency for more trade winds to be occurring now that we passed the opportunity for the main Kelvin Wave. Years that had a resurgence of Niña like 1955 and 1999 did have a warmer summer nationally...throw in a lack of blocking aside from a -EPO that won't influence places except for the Northern Tier, and I think the recipe for a toasty one is set:

I am aware my preliminary forecast looks exactly contrast to the post-Niña summers which has a cool South/Southeast and a warmer Northern Plains, but here it is:

Looks like you are banking on a negative nao. It would give you a temp pattern much like your bottom map.

[skierinvermont]

Looks like you are banking on a negative nao. It would give you a temp pattern much like your bottom map.

Looks like a -NAO summer pattern to me as well, but he said he's expecting a +NAO which correlates well to a below average southern tier and above average northern tier, basically the opposite of his map.

So what does this all mean for the summer? Well, unlike last year, I'm expecting a more +NAO summer...

[BethesdaWX]

Wasn't last summer a -NAO? Using HLB alone to forecast a temperature gradient seems dangerous.

[usedtobe]

Wasn't last summer a -NAO? Using HLB alone to forecast a temperature gradient seems dangerous.

Last year was a negative nao summer. I have no feeling whether this will be a positive or negative nao summer but the pattern of warm over the south and cold over the north is pretty typical of a negative nao durin gthe summer months. Here's the correlation of NAO index with temperature during summer.

The correlation is the opposite of the winter one.

[skierinvermont]

And that's pretty consistent with temperatures last summer with the widespread heat concentrated in the southern and central U.S., although the heat was more widespread than one would expect solely on the NAO as some it spread northwards as well.