SUMMER PREVIEW --
20 MAY 2007
|1. REVIEW OF SPRING 2007||5. THE DROUGHT AREAS|
|2. SUMMER 2007 OVERALL||6. La NINA BASICS for SUMMER of 2007|
|3. FORECAST MAPS||7 LA NINA THREAT FOR 2007|
|4. THE OVERALL PATTERN GOING INTO THE SUMMER 2007||8 HURRICANE SEASON 2007|
Text that is in BOLD highlights important ideas or statements. RED BOLD has been so designated because it contains CRITICAL ideas.
Throughout this forecast you will see the acronym "CF" used. The two letters "CF" stands for "Consensus Forecast" which is term that I use to describe the general view or a summary of what most PWSIP (private weather service Information Services) and / or NWS forecasters are saying. The CF is very important in determining how the seasonal trade in Energy and Agriculture markets will unfold as well the operational side of the weather biz. For example State DOTs will often significantly lower their Salt and Sand purchases if the CF is for a Mild winter in their areas. The CF often consists of
a) the CPC (Climate Prediction Center)
carry a lot of weight...
b) large well known Private Weather Service Information Provider (PWSIPs) and
c) some well known Energy/ Ag forecasters.
REVIEW of SPRING 2007
Click on IMAGES to see FULL MAP
The actual forecast can be seen HERE
As a general making seasonal
forecasts for the intermediate seasons -- Autumn & Spring -- are always harder
to make a seasonal forecasts when compared to Summer and Winter seasons. Still
the WxRisk.com Spring forecast was a fairly good but as great as the forecast I
made last Summer (2006).
MARCH 2006 as you can see the temperatures were quite warm over much of the CONUS with a small area of Paul normal temperatures over going on. My temperature forecast called for huge area of above normal temperatures over the heart western and central US but I did not have the above normal as far east --into the Midwest which is exactly what happened in reality. Precipitation wise I did OK over the Southwest states correctly forecasting the Drier than Normal conditions. But I did not pick up on the developing drought over the Southeastern states at all.
APRIL 2006 -- I correctly forecasted the large area of above normal temperatures over the Southwest and central Rockies but I had the above normal temperatures expanding into the Upper Plains and western Great Lakes which was clearly incorrect. I did had an area of Below Normal Temperatures over the Southeast which is not bad but the Below Normal temps I had on my April temperature forecast map did not reaching TX /OK which had a cool month nor did cover northeast was also had a cool April 2007. With regard to the rainfall I had a large area of Drier than Normal conditions over all the Plains and the Midwest which was clearly incorrect and I missed the southern drought again.
MAY 2007 -- my temperature forecast has pretty good so far ... through 5/19. I did not have the area of above normal temperatures reaching all the way into the Ohio valley but in general the temperature forecast has been pretty good. The precipitation forecast for May 2007 was completely wrong.
SUMMER 2007 OVERALL
The Summer of 2007 has a far greater chance than " normal" to have a significant weather problems over large portions of the CONUS as well as the return of significantly Above Normal Hurricane activity in MDR -- Main Development Region of the Tropics (....Tropical Atlantic.... Southeast US Coast... Caribbean Basin and the Gulf of Mexico). A careful study of the significant changes in the pattern over the last 30 days clearly shows or reveals what will likely be the main Summer pattern of 2007.
The overall Summer pattern is going to be determined by several important features.
The large drought area which have developed over the Southwest states and much of the central and northern Rockies
A 2nd but very important drought area over the Deep South that is rapidly expanding and intensifying. This 2nd drought area has already expanded into the Tennessee Valley
A strong and active Pacific Jet stream which will be keeping the mean trough either right along the immediate coastal areas of western North America/ eastern Pacific or over the Pacific Northwest region of North America.
The QBO will continue to drop into the Negative numbers.... probably reaching -20 or greater during the Heart of the Hurricane season.
Unlike Last Season rainfall over Equatorial west Africa in MAY has been Normal to Above Normal so the severe Dust will not be nearly as bad this season when compared to what we saw in the 2006 Hurricane season.
In addition Wxrisk.com sees at least a 50% chance a moderate La Nina developing during the heart of the Summer and into the early autumn and a 25% of seeing the La Nina reaching STRONG threshold for several weeks
HURRICANE SEASON ---Unlike
most private forecasting services as well as government agencies WxRisk.com in
2006 was one of the few well-known PWSIP (Private
weather information Service Providers) that did NOT go for
an Active Hurricane season. And as the 2006 season progressed... that forecast never
from the 2006 Hurricane season forecast
The Hurricane season of 2006 will NOT be nearly as bad as many forecasters are forecasting. WxRisk is calling for 13 named Tropical Cyclones... and it could less than that IF an El Nino develops by AUGUST 2006. There will be nothing like the severe Hurricane activity in the Gulf . WXRISK also strongly disagrees with the assertion made by some other well known Private weather forecast services that the East coast will see an increased chance of seeing several Land falling Hurricane or near Misses in 2006. In fact WXRISK sees a late Summer early Autumn pattern that makes such a forecast extremely unlikely.
click on the two links below to see a FULL review of the of 2006 Summer season forecast and the 2006 Hurricane Season. http://wxrisk.com/Seasonalforcst/Summer2006/summer2006.htm
There were several specific reasons why I forecasted a hurricane season that had activity that was much below expectations....
The lack of Moisture over western and southwest Africa. Studies have shown that Drier than Normal Spring and early Summers can often lead to weaker than Normal Tropical waves coming off the Africa coast (called Cape Verde systems in the weather biz) .
And Drier than Normal Springs and early Summer season often lead to increased heavy Dust events that literally choke off and shut down any tropical system in the far eastern Atlantic .
Many of the Summer and Hurricane forecasts of 2006 were issued extremely early . These early Summer forecasts issued in APRIL of 2006 could not possibly work out since the premise of those forecasts was based on
A) the weak la Nina would last into the Summer of 2006 when in fact the La Nina was already dying. If the La Nina of SPRING 2006 died then we would have La Nada-- or Neutral Conditions in the Equatorial.
B) In Fact an El Nino developed in Late July and August of 2006. Many forecasters have since asserted that the El Nino developing in JULY and AUGUST of 2006 were a surprise .... when in Fact WXRISK.COM did forecast a El Nino for the 2nd half of the Summer of 2006 ( El Nino events reduced Hurricane activity in the MDR while La Nina event enhance it) .
The QBO massive switch 2005 vs 2006. The 3 most destructive and active months of any Hurricane season on record was AUG / SEPT/ OCT 2005. In those months the AUGUST of 2005 QBO value was the strongest Negative Value AUG value ever recorded (since 1950) and 3rd lowest of all time. The QBO value in SEPT 2005 was the lowest Negative QBO value EVER as was OCTOBER 2005. Now in AUG 2006 (+9.10) the QBO was 35 points HIGHER than AUG 2005 .... In SEPT 2006 (+10.20) the QBO Value was 37 points higher .... and in OCT 2006 the QBO value (+10.86) was again +40 Points higher when compared to OCT 2005 . The point is that this massive swing in the QBO was NOT supportive of the forecast for a Much above Normal activity Hurricane season for 2006 .
This time around WxRisk.com does see an INCREASED probability of significantly More active Hurricane season for 2007 . However where I disagree with the consensus forecasts is the subject matter of which regions of the US Coasts are more likely to be hit.... ( Gulf / Florida / SE US coast / NE US CONUS). I see a much reduced chance of the central and eastern Gulf as well as the SE Coast and the Northeast coast being hit as well a much reduced chance of central and northern portions of the Texas coast being hit this year.... with an increased chance of areas from Brownsville /southern TX southward into northern and central Mexico getting hit ... Nor do I see the 2007 Hurricane as a New England year either...
THE FORECAST MAPS
SUMMARY OF 2007 CONDITIONS.... as I
mentioned above the Summer 2007 forecast is based upon several concepts
some which are Now in place and some which are STILL developing and thus pose a
certain amount of uncertainty to this forecast. For
example I strongly suspect that the developing La Nina will reach the MODERATE
threshold and it has a fair chance of reaching the STRONG criteria late in
the Summer ( even if only for a weeks). On the other hand
if La Nina does not develop as forecasted then obviously it would greatly affect
the Summer forecast. The large drought area which now exists over in
the Southwest into the Great Basin and Rockies is a "SET"
feature that is not going change much
this Summer 2007 . Another slight uncertainty is the
developing drought area over the Deep South .
In order to fall this narrative closely I need to set up basic reminders about Weather without getting too technical.
First keep in mind that for every Ridge there is a Trough and for every Trough there is a Ridge.
Second as we move into the heart of the Summer the Jet stream will continue to shift to the north as it always does this time of year (conversely in the Autumn and winter months the Jet stream shifts to the south).
Third large dry areas CAN in
SOME weather patterns enhance the overall Jet stream pattern in some areas.
Fourth Large and persistent pools of Cold or Warm Sea Surface Temperatures (SSTAs) DO affect the Overall Jet Stream .... examples of this would be a La Nina or El Nino or large amounts of Cold SSTA off the West coast of Canada .
Also... the energy region MRO is a close match to the agricultural regions of the Plains & WCB. Likewise the western & central portions of the energy region RFC is equivalent to the ECB
THE OVERALL PATTERN GOING INTO THE SUMMER 2007
The mean pattern we have seen for MAY 2007 has been significantly different from what we saw in March and April. This image depicts the atmosphere across the northern hemisphere at the jet stream level on 8 APRIL 2007.
We can see several important features typical of a mid- Spring pattern -- the areas of dark BLUE represent deep troughs and the Bright RED strong Ridges. As you can see there is a pretty deep trough over the Great Lakes and the Northeast last and no large and deep trough over the eastern Pacific south of the Gulf of Alaska. Not surprisingly this are pattern produced temperatures that were close to normal but also a pattern that was rather wet for much of the central and eastern CONUS. This pattern which produced a wet and cold APRIL for the central and eastern CONUS was a dry one for most of the Deep South as most of the weather systems passed by to the North. As a result the dryness over the deep South over the winter worsen significantly in APRIL and MAY .
APRIL and MAY 2007 have both featured a persistent trough centered over the Pacific Northwest or in over eastern Pacific just off the coast of North America and a pretty strong Ridge over the Rockies. One of the reasons WHY the Trough over the Pacific NW/ Eastern Pacific has been so active this Spring has been the large pool of Cold SSTs (sea surface temps) off the West coast of North America. Let take a look at some of these SSTA maps.
15 APRIL 2007 ... There is large area of cold and very cold SSTs in the Eastern Pacific... from the Gulf of Alaska to off the Baja California coast AND note the large pool of Cold water off the Northeast CONUS coast . Note the cold water pools seem to match up closely with the dark BLUE in the Map above .
6 MAY 2007 -- if anything the areas of cold SSTs in the eastern Pacific has Increased -- in actual coverage and intensity and the cold water of the Northeast CONUS coast has held steady.
20 MAY 2007. As you can see there has been Little if any change in the large pools of cold SSTs in either the Pacific OR in the northwest Atlantic (off the NE CONUS coast)
Since the Jet stream starts in
early APRIL is still fairly far to the south... weather systems have
been tracking into the Pacific NW then moving OVER the top of the Ridge in the northern Rockies have been
dropping down across the Upper Plains into the Great Lakes and Midwest and these
systems have been producing significant rains over much of the Plains/ WCB- MRO
However as you
know the weather pattern over North America for
MAY 2007 is significantly different from what we saw in late March and
APRIL 2007. WHY? One of the reasons is that as you move
into the Summer months the Jet stream of course is going to shift to the North
as it always does. But this typical shift to the north actually allowed the
drought over the Deep South to intensify over the last 30-45 days since there is
now even less chance of seeing significant rains reaching into the Deep South
that we saw in early in April.
As I stated above the development Drought areas - not just a few areas where it is drier than normal but persistent and long-lasting Drought -- can alter a Jet stream pattern much the same way as large areas of cold or warm sea surface temperatures can alter the pattern.
Here is the mean Jet stream pattern for 11 May 2007. I have highlighted the trough and Ridge positions over North America. Here is the May 15 drought monitor map. Again you can clearly know the large drought area over the Southwest the Great Basin and the Rockies and the second drought area over the Deep South.
Now what I've done on this next map is shown where these drought areas would appear on the first map and as you can see the Jet stream appears to be matching the drought areas amazingly well.
Not surprisingly with this sorted of Jet stream pattern we have seen some pretty warm temperatures developing over much of the central US (Plains and Midwest) ... and portions of the Rockies. This map shows a 30-day temperatures from April 18 - May 19 ... and this map shows the temperatures from May 1 to the 19th.
This sort of pattern COULD actually be a good one for those looking for seasonal temps and seasonal rainfall over the Plains and eastern CONUS. For example Here is the drought Map from the Middle of MAY 2004 and as you can see in Mid MAY 2004 the drought over the western CONUS was very similar to what we currently have over the WESTERN CONUS. That western US drought of the Spring and Summer 2004 did NOT impact the central and eastern US. On a seasonal scale the ridge over the Western US supported a deep trough over the Midwest so while there were intervals of hot and dry weather across the central and eastern CONUS these intervals were all pretty typical of what one expects to see during the Summer months. There were no sustained heat waves or droughts during the summer of 2004 over the central and eastern CONUS.
But there is of course a BIG
difference between the 2004 drought map and the one we see for the middle of May
2007. The critical difference is the expanding drought over the Deep South which
in my opinion has already fundamentally alter the pattern. Without the
developing drought developing over the Deep South the overall pattern would look
something like this ... we would still have the drought over the Western CONUS
and still the mean trough and eastern Pacific.
This map is essentially similar to what saw in the Summer of 2004. But as you can see the developing drought over the Deep South alters the pattern because instead of seeing the deep trough over the Midwest and Northeast as we saw in the Summer of 2004 -- which are provide strong cold front and consistent rains -- the drought areas over the Deep South in MAY 2007 is keeping the trough over the Great Lakes very shallow.
This is why in my opinion we have seen a much drier overall pattern over the past 30 days east of the Mississippi River. Without the developing drought area over the Deep South the is what the overall pattern would probably look like for the Summer of 2007....
On the other hand the
eastern Pacific trough / WESTERN CONUS Drought area
supports or Teleconnects to the trough over
the Upper Plains .... this has allowed the very wet pattern of APRIL
2007 to continue over the central & Upper Plains in much of
MAY 2007. In this sense the persistent trough over the Plains and the
Ridge over the eastern US are directly connected.
The effect of this rainy pattern over the Plains can be seen by the MAY 12 edition OF PALMER MOISTURE MAP. What is important to note are the 2 Dark GREEN areas ...one over the Plains from TX into eastern SD and western IA and the other over the Northeast... which also had a wet Spring season. The DRY areas can bee seen by the ORANGE and YELLOW areas.... over CALIF and the SW states into the Rockies and the 2nd area over the Deep South.
THE FUTURE OF THE DROUGHT AREAS OVER THE
WESTERN CONUS & DEEP SOUTH?
However all this being said there is
no guarantee OR even a reasonable amount of certainty that the
drought conditions over particular area will hold or expand. There are numerous
examples of drought areas shrinking during the Spring and
Summer months. We simply cannot look at a drought map and a sea surface
temperature map and conclude that this is what the overall mean pattern is going
to look like for the Summer of 2007
One of the ways that forecasters can follow the expansion of the drought Areas is the use the long-term and short-term drought trends indicator Maps. This product is produced by the folks at the Climate Prediction Center and it is a relatively new product and one which is not been used by most forecasters and forecasting services. However I find this to be particularly useful product in figuring out moisture and drought trends.
Here is the long-term drought command from 5 MAY 2007... AND 19 MAY 2007. These maps are pretty self explanatory. On the long-term drought indicator map of May 5 we can see the drought developing over the Deep South quite nicely as well as the dry conditions of the Southwest and Rockies. But is also very wet conditions over the Ohio valley ( read as ECB/ RFC) as well as the Northeast US. And there is a second area of fairly wet conditions over the central lower Plains running from North Dakota and Minnesota down into Western Texas and New Mexico. If you are to compare these two maps you will see some minor changes over portions of the Plains bike increase in drought developing over northern Florida Southern Georgia and portions of Alabama.
Now lets take a look at the short-term drought indicator Blend maps. Not surprisingly we can see more impressive changes... which of course we should given that this is a short-term drought indicator which involves the trends in precipitation over the past several weeks.
The Wet conditions over Western TX and NM increased from 5 MAY to 19 MAY but the drought conditions over the northern Rockies in the Great Basin also worsened ...shifting from the Yellow to the Red and Brown shadings indicating a significant drying. Over the Plains the Dark blue and Greens that we see on May 5 over KS NEB eastern SD and western IA weakened some which shows SOME drying over the central and Upper Plains (this slow drying is fairly close to normal for the middle and end of MAY). However the major changes in the 5 MAY to 19 MAY time frame was over the Eastern US. First the drought over the Deep South has expanded dramatically and is turned ugly looking with Dark Reds across the entire region!!! This is an impressive change in last two weeks. In addition the Midwest east of the Mississippi which on MAY 5 was close to normal with regards to recent Precipitation as also increased significantly towards the Drier side with moderate drought conditions expanding into Kentucky and southeastern Ohio. And lastly we can see that the wet conditions on 5 MAY in New England have significantly weakened
HYPOTHESIS .... HOW THE LARGE DROUGHT AREAS WILL AFFECT THE SUMMER 2007 PATTERN?
If one were to look at the top 5 driest SPRING seasons over the SE CONUS then searched the data to see what the following Summer seasons were like... you would end up with these two Maps. You end up with DRY Midwest - Delta Deep South some drying over the Plains but also cooler than Normal temperatures over the Deep South and Midwest. How can this be? well typically when there is DRY Spring season over the SE CONUS this comes about because the Jet stream pattern features a deep trough over the Eastern US. This allows HIGH pressure areas to plunges from the Midwest into the Gulf coast . This track of the HIGH pressures areas brings in cool temps but also shuts off the moisture from the Gulf of Mexico
However for THIS Summer the large drought area over the southwest Great Basin and Rockies COMBINED with the drought area over the Deep South will ensure that we will NOT see a cool and dry Summer in 2007.
If we were to focus JUST of the BIG western CONUS drought and the top driest SPRING seasons -- MARCH to MAT then see what Those Summers were like again we get a strong HEAT signal
La NINA BASICS for SUMMER of 2007
The potential development of
La Nina event for the summer of 2007 as already been much talk about so I'm not
going to go into a great deal in detail with regard to this feature. But I do
have a few things to say on it. First you need to understand where and how the
La Nina or El Niņo events are declared by CPC department pictures Center.
El Niņo (warm water) and La Nina (cold water) events occur in a specific portion of the equatorial portion of the Pacific Ocean... this area is known as the ENSO regions and it can be seen here. As you can tell there are FOUR specific areas in the ENSO region.
REGION 1 and 2 is situated right along the Peru coast just SOUTH of the Equatorial.
REGION 3 is the Red box area along the Equator.
REGION 4 is the Yellow area which extends along the Equator out past the Dateline.
REGION 3.4 is area shown by the THICK BLACK LINE .
El Niņo and La Nina events are
"born" develop intensify then weaken in the various sectors of the ENSO regions
El Niņo and online Nina events are declared by CPC when they reach certain threshold criteria for a certain period of time. CPC will declare a El Niņo or La Nina event ONLY when the warm or cold SSTs are either +0.5 degrees Celsius above Normal / -0.5 degrees Celsius Below Normal for three consecutive months in ENSO region 3. 4. When that threshold is reached CPC officially declares that a El Niņo and La Nina event is underway.
Using ENSO region 3.4 works very well when you are dealing with El Niņo events but when you are dealing with La Nina events there is problem. Almost all of the moderate to strong La Nina events that have develop since 1950 how formed off the coast of Peru ... ENSO region 1.2. The cold SSTAs and have then spread westward towards ENSO region 3 and 4. Using the official criteria from CPC will often result in a very late call from them because they're criteria is based upon region 3.4. There have been many cases where the cold SSTAs have developed off the coast of Peru (ENSO region 1.2) for several weeks if not a few months before the Cold SSTAs finally migrate into region 3.4 and then stays cold for at least 3 months!
As a result the forecasters and traders which are relying were counting on the official declaration of a La Nina event from CPC will often end up behind the curve since the La Nina event will often be underway for several weeks before CPC finally gets around to officially declaring the La Nina event is underway.
Also you need to know that there are TWO primary sources for getting the latest data that meteorologists use for SSTAs in the various ENSO regions. MOST forecasters and forecast services use the data from CPC ... this is the LINK
However the Australians also provide track SSTA in the ENSO regions .... but for some reason many forecasts dont know about this source of data. The competing sources of data can be is disagreement sometimes but the evidence is clear. The data from the Aussies is far superior to data from CPC because of the data cutoff. You see BOTH sources issue the latest data Monday Morning. BUT the Data from CPC covers the period from the Previous Friday -- 8 days before the date up to last Thursday. So in other words the CPC data when it comes out Monday morning does NOT include any data from last Friday or Saturday. The Aussies data when it is issued Monday morning covers the period from the previous Sunday to Saturday and therefore has the latest data.
Taking a look at the latest surface temperature maps -- the ones I posted above --- we can clearly see the developing La Nina event right along the Equatorial Pacific.... note the very dark blues and purple color areas off the coast of Peru.
It is not simply a matter of stating that because ANY La Nina that develops you can therefore forecast with a reasonable degree of certainty what the conditions are going to be like over much of the central and eastern CONUS this Summer or the hurricane season is going to be like Atlantic Basin.
However there is a strong connection between Moderate or Strong La Nina events and significantly Hotter and drier summer ( possibly drought conditions). These maps show the Mean temperatures and Precipitation anomalies in the summer JUNE JULY and AUGUST based on average of 12 Moderate and strong La Nina events.
These Maps speak for themselves....
In JUNE Moderate and Strong La Nina events
bring near Normal temps but Much
Below Normal rainfall over the
Plains and Midwest and Above Normal rainfall over
the SE states! In JULY temps tend to run
Above Normal over the Plains and
Midwest and its very dry... but over
the SE states precip is
still slightly Above Normal.
Of course these maps are the MEAN or Averages of 12 Moderate / strong La Nina seasons The SUMMER of 2007 will feature two large drought areas so these images have to be adjusted to fit the current Reality.
THE LA NINA THREAT FOR 2007
Over the past several weeks there has been a lot of talk and speculation about the La Nina Threat for the Summer of 2007.... The opinions have ranged from "its coming"... to "Its fading" ... to "it has stabilized".... to "its taking a long time to develop..."
Getting this correct is HUGE because the development of a Moderate / Strong la Nina vs Weak La Nina versus NO La Nina has huge implications. As I mentioned above Part of the problem is that some of these private forecasts are focusing ONLY on ENSO region 3.4 which means the La Nina could NOT possibly be declared before AUG 2007 at the earliest. But as I have shown ( proven) Most Moderate / strong La Nina events develop in ENSO region 1.2 MONTHS before the cold water reaches Region 3.4.... thus by the time CPC officially declares LA NINA the event could have been underway for many weeks.
Next keep in mind that there
are a lot of climate models that are used in forecasting
El Nino / La Nina events... but the best known of these 19 climate
models is the CFS (climate forecasting system).
The good thing about the CFS is that the model is
daily and actually consists of 20 "versions ".
The good thing about the CFS is NOT that is a
more accurate model than these other climate
models but that forecasters can see the
TRENDS of the model every day.
The chart shows the most recent Climate models and their forecast for SSTAs in ENSO region 3.4 as of 21 MAY. Most of the climate models shows a weak to Moderate La Nina event BUT these models all start off with a temperatures Anomaly of +0.2 degrees C when in fact ENSO Region 3.4 was at -0.25 degrees C. In other words all of the climate Models start with warm SSTS in ENSO region 3.4
These next four maps are some recent runs of the CFS for the 2 BIG or important
ENSO regions... Region 1.2 and Region 3.4. These images are pretty self
explanatory but I did want a point out that while there is some variation in
these runs from time to time ....since early April the CFS has been remarkably
consistent showing a moderate to strong La Nina developing over both these
regions during the heart of the Summer months.
There is some slight differences... for example the APRIL 2 edition of the CFS for region 1.2 showed a very strong La Nina developing by late in spring or early in the summer.... however the May 22 edition of the CFS is not quite as intense with the cold SSTAs in Region 1.2. On the other hand the graphs from April 2 CFS for Region 3.4 is actually quite similar to what we see with the CFS on the May 23 edition ... a moderate to borderline strong La Nina event that develops by July and lasts at least a few months taking us into the early autumn for months
Finally let me conclude that there
besides the use of sometimes unreliable and somewhat speculative computer models
to forecast El Niņo or La Nina events there is a source of data which is out
there on Internet (for free) which can be used to provide almost real-time
updates with regard to the ENSO regions.
Just as the Jet stream drives cold fronts and High-pressure and Low-pressure areas across the world research indicates that the subsurface temperatures from the ocean surface down to about 300 meters is often very important.... and can tell forecasters whether or not the surface Ocean water temperatures might be increasing or decreasing.
The important thing to note here is
that the subsurface temperature profiles show that when large bubbles off cold
water appeared or develop beneath the surface and propagated towards the surface
in easterly direction--- towards PERU Coast / ENSO region 1.2 -- there were
significant drops in the SSTA in the that region... and lesser drops in the
SSTAs in ENSO region 3 ENSO region 4 and ENSO region 3.4
|SUB SURFACE TEMPS IN THE ENSO REGIONS|
|MARCH 28||APRIL 8||MAY 4||MAY 20|
|HERE WE CAN SEE A LARGE POOL OF COLD SSTAs (BLUE SHADING BUILDING) WAS RISING TOWARDS THE PERU COAST (ENSO 1.2) . AT THIS TIME THE SSTs IN THE ENSO REGIONS SHOWED THEIR FIRST BIG DROPS OF THE SPRING DROP||The Large Pool of COLD SSTAs (BLUE SHADING BUILDING) WEAKENED AND THE DROP IN SSTAs LEVELED OFF IN EARLY & MID APRIL||The Large Pool of COLD SSTAs (BLUE SHADING BUILDING) WAS STEADY AND THIS ALLOWED TEMPS IN THE VARIOUS ENSO REGIONS TO HOLD STEADY||The Large Pool of COLD SSTAs (BLUE SHADING BUILDING) WAS INCREASING ...IN SIZE AND DEPTH OF THE COLD WATER.|
HURRICANE SEASON 2007
Obviously a great deal is going to
depend on whether the forecasters are basing their hurricane forecast on
the development of a Weak Moderate or Strong La Nina
event. As I am sure you already know by now moderate or strong La
Nina events greatly enhance hurricane activity in the Atlantic Basin and
suppress hurricane activity off the eastern Pacific Mexican coast.
Some of the hurricane forecast numbers that have come out from the government and from some of the private weather forecasters are beginning to sound a little like a game of one-up-mans- ship which is kind of like the problem we had last season.
While this Summer 2007 forecast was been prepared ... TPC / CPC released their new Hurricane 2007 forecast. All of these various forecasts sure do get a lot of Media attention and given the sensitivity to America's energy needs this is not a surprise.
Keep in mind that 98% of all La Nina hurricane seasons have averaged a least one week's worth of disruption in the Gulf of Mexico from production of Natural Gas and Oil with the average disruption in a typical La Nina Hurricane season is about 98 BBLS.
Here is the sea surface temperature map from the middle of May 2005. As you can see there was a large pool of one warm SSTAs located in the tropical Atlantic Ocean. When you compare that map to the current one for the know of May 2007 we see no such large pool warmer than normal SSTs in the Atlantic Basin.
MAY 2005 MAY 2007
On the other hand the rainfall for the April over Southwest Africa has been pretty good. Not great but certainly wetter than last year with the percentages running 25 to 50% above normal. This is slightly wetter than normal rainfall is likely to reduce the development of large and powerful dust storms coming off the sw coast of Africa and interfering with development of Tropical Waves moving from the African coast to the Cape Verde Islands into the far Eastern Atlantic.
If we start from the premise of a La Nina developing late in the Spring or in the Summer.... there have only been FOUR La Nina events since 1950 that began in that time frame. 1995 and 1998 are two of the more famous events and often times these years get mentioned as possible hurricane analogs to the upcoming 2007 season.
However both of those seasons the QBO that were strongly positive and this year for the QBO over the late summer and early autumn will once again run strongly negative. For these reasons I cannot use the 1995 or 1988 hurricane seasons as a analog to the 2007 Hurricane season.
Instead I kind of like the la Nina Hurricane season of 1964 that is often over looked. Not only was a 1964 Moderate La Nina but the QBO was strongly negative in that season as well .
Interestingly the 1964 hurricane season featured several systems that developed in and around the Central North for a Georgia coast... was some of the storms coming across floor into the Gulf ... in a manner sort of which was similar to some tropical storm ANDRE back in the early portions of May 2007.
The one area that I do not see as a High threat is the central and central TX coastal -- Corpus Christi to Galveston Bay.
The reasoning is based on the idea that the largest drought area centered over the Southwest states ...the Great Basin and the Rockies is likely to favor a strong Ridge anchoring itself in or near the four Corners region of the Southwest. This sort of strong Ridge is probably going to extend out into Texas and as a result any sort of tropical storm or Hurricane which is tracking W or NW towards the central and northern Texas coast is going to be "deflected" or held back by the strong Ridge over the 4 corners / sw states region. As result any sort of Tropical cyclone which comes into the Central golf is likely to bend to the WSW or even SW and make a possible impact south of Brownsville Texas sparing the main natural gas platforms along the central and northern TX Gulf coast.
For the East Coast I see several possible landfall threats in and around the Southeast--- by that I mean from Cape Hatteras south to Jacksonville FL -- but I don't see a particularly favorable pattern for r hurricanes tracking up into New England. I see the mean trough holding over southeastern Canada which is close enough to New England to ensure Hurricanes would curve out to sea or perhaps just clipping southeastern New England (Cape Cod area).
My forecast calls for 15 Named storms of which10 will be hurricanes and 3 intense Hurricanes. IF the La Nina reaches the strong threshold criteria at any point during hurricane season months of August September October... you can raise those numbers to 18 12 and 6 respectively
REVIEW of WINTER FORECAST
This link will bring you to the winter forecast of 2005 --06. The actual forecast can be seen HERE
In the Winter of 2006 --07 WXRISK.COM asserted the following...
The was going to be colder and snowier than expected by the CF (consensus Forecast) over the Midwest and Northeast but NOT colder and / or snowier winter than Normal for most areas
El Nino would NOT reach the Moderate or Strong criteria for sustained period during the winter months... but the El Nino might have a short interval when the El Nino technically reach the "moderate threshold" for a few weeks.
However the second half of the winter in particular will see a decline in the strength and power of this weak El Nino event.
The drought conditions that developed over the lower Plains and eastern Rockies would end in the 2nd of the winter as "split jet stream pattern" developed.
The first half the winter will feature a Above Normal precip over the Pacific NW and warm eastern US in the half
But right now I see the second half the winter as one that is more stormy and cold for the eastern half of the CONUS.