Econintersect Climate and Weather Update, 04 August 2014
Written by Sig Silber
And there are no fiber-optics involved.
Plus NOAA has updated their August Outlook for the U.S. and they do not seem real confident about it. And today’s 6 – 14 Day Outlook bears no resemblance to the August Outlook. Australia says “not so fast on an El Nino”. Is anyone in charge here? The answer is yes: Mother Nature.
First let’s start with the NOAA. On July 17 the following early Outlook was issued for August.
Here is the Outlook issued on July 31. Notice that the area of above climatology temperature in the Southeast has shrunk from the early Outlook.
And here is the early Outlook on precipitation issued on July 17.
And here is the new Outlook on precipitation issued on July 31. Notice the Southeast drought area has been removed except for South Texas.
And here are some excerpts from the discussion that was issued with the maps. Any bold type is emphasis that I have added.
“PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300PM EDT THURSDAY JUL 31 2014
30-DAY OUTLOOK DISCUSSION FOR AUGUST 2014
THE UPDATED 30-DAY OUTLOOK FOR AUGUST 2014 DEPICTS SIGNIFICANT CHANGES FROM THE 0.5-MONTH LEAD OUTLOOK ISSUED JULY 17. THIS IS PARTLY DUE TO SUBSTANTIAL VARIATIONS IN DAY-TO-DAY RUNS OF THE CFS, POTENTIALLY RELATED TO TWO WESTERN PACIFIC TYPHOONS AND THEIR ASSOCIATED INFLUENCE ON THE MID-LATITUDE CIRCULATION UPSTREAM OF THE UNITED STATES. RECENTLY, A WESTERN PACIFIC TYPHOON WAS ABSORBED INTO THE MID-LATITUDE CIRCULATION OFF EAST ASIA, AND MAY HAVE BEEN RELATED TO AN AMPLIFICATION OF THE FLOW PATTERN DOWNSTREAM OVER THE UNITED STATES, FAVORING A WESTERN RIDGE AND EASTERN TROUGH. IT IS CONCEIVABLE THAT THIS SITUATION COULD OCCUR AGAIN AS TWO WESTERN PACIFIC TYPHOONS ARE PREDICTED TO GET CAUGHT UP IN THE WESTERLIES AND USHERED DOWNSTREAM TOWARDS THE UNITED STATES. THE UPDATED 30-DAY OUTLOOK IS BASED PRIMARILY ON FORECASTS OF TEMPERATURE AND PRECIPITATION PATTERNS OUT THROUGH THE EXTENDED-RANGE (THROUGH THE FIRST HALF OF AUGUST), AND RECENT RUNS OF THE CFS. THE ANTICIPATED BACKGROUND 500-HPA CIRCULATION PATTERN THROUGH AT LEAST THE MIDDLE OF AUGUST FAVORS A TROUGH NEAR THE ALEUTIANS, A RIDGE OVER THE FAR WESTERN CONUS, AND ANOTHER TROUGH OVER THE EAST-CENTRAL CONUS. ENSO COMPOSITES PLAYED A VERY SMALL ROLE IN THIS OUTLOOK. IT IS IMPORTANT TO POINT OUT THAT THE LATEST RUNS OF THE GFS (AS OPPOSED TO CFS) MODEL PREDICT A RELAXATION OF THE SOUTHWEST MONSOON DURING WEEK 2, AFTER AN ACTIVE WEEK 1 PERIOD. HOWEVER, THIS RELAXATION APPEARS SHORT-LIVED AND IT WAS DECIDED NOT TO MODIFY THE 30-DAY PRECIPITATION OUTLOOK AS IT NOW STANDS.
THE UPDATED MONTHLY TEMPERATURE OUTLOOK FOR AUGUST 2014 FAVORS ABOVE-NORMAL MEAN TEMPERATURES OVER THE FAR WESTERN CONUS, FLORIDA AND ADJACENT PORTIONS OF BOTH GEORGIA AND ALABAMA, AND ALASKA. BELOW-NORMAL MONTHLY MEAN TEMPERATURES ARE FAVORED OVER THE NORTHERN AND CENTRAL PLAINS, THE UPPER AND MIDDLE MISSISSIPPI VALLEY, AND THE WESTERN GREAT LAKES REGION. SINCE THE RELEASE OF THE 0.5-MONTH LEAD TEMPERATURE OUTLOOK ON JULY 17TH, THE CFS HAS TRENDED COLDER OVER MOST OF THE CONUS, ESPECIALLY OVER THE WEST-CENTRAL AND NORTH-CENTRAL STATES. THE LARGE AREAS OF FAVORED ABOVE-NORMAL MONTHLY MEAN TEMPERATURES ON THE PREVIOUS OUTLOOK HAVE BEEN REDUCED IN SIZE TO INCLUDE ONLY THE FAR WEST, FLORIDA. THE CFS PREDICTIONS FOR ALASKA HAVE BEEN FAIRLY STABLE, WITH THE BEST CHANCES FOR RELATIVE WARMTH OVER THE SOUTHERN AND SOUTHWESTERN PORTIONS OF ALASKA, WITH DECREASING PROBABILITIES FARTHER NORTH. IN AREAS WHERE CLIMATE SIGNALS ARE WEAK AND/OR UNRELIABLE, EQUAL CHANCES (EC) OF BELOW-, NEAR-, AND ABOVE-NORMAL MONTHLY MEAN TEMPERATURES IS INDICATED. THE UPDATED MONTHLY PRECIPITATION OUTLOOK INDICATES ELEVATED ODDS OF ABOVE-MEDIAN PRECIPITATION FROM EASTERN ARIZONA AND COLORADO EASTWARD TO INCLUDE NEW MEXICO AND THE SOUTH-CENTRAL PLAINS. THERE ARE ELEVATED ODDS OF BELOW-MEDIAN PRECIPITATION OVER SOUTHERN TEXAS. THESE TWO SIGNALS ARE REASONABLY CONSISTENT WITH PRECIPITATION DYNAMICAL MODEL GUIDANCE OUT THROUGH 2 WEEKS. IT IS THOUGHT THAT MONSOONAL ACTIVITY WILL BE MORE CONCENTRATED IN THE EASTERN MONSOON REGION (NEW MEXICO, COLORADO, WEST TEXAS), THOUGH AREAS FARTHER WEST ARE ALSO EXPECTED TO RECEIVE MONSOONAL MOISTURE. IN ADDITION, A MEAN FRONTAL BOUNDARY IS PREDICTED TO BE POSITIONED SOMEWHERE IN THE VICINITY OF COLORADO AND WYOMING SOUTHEASTWARD TOWARDS ARKANSAS. RECENT RUNS OF THE CFS CONTINUE TO FAVOR ABOVE-MEDIAN PRECIPITATION ACROSS MOST OF THE INTERIOR WEST, AS WELL AS BELOW-MEDIAN PRECIPITATION IN THE GENERAL VICINITY OF THE GULF COAST. IT IS THOUGHT THAT THE CFS IS OVERDOING BOTH OF THESE SIGNALS, ESPECIALLY THE FAVORED WETNESS IN THE INTERIOR WEST. THE SIGNAL FOR ENHANCED CHANCES OF BELOW-MEDIAN PRECIPITATION IN SOUTHERN TEXAS IS FAIRLY ROBUST. A FINAL CONSIDERATION INVOLVES DROUGHT IN THE SOUTHEAST. WIDESPREAD DETERIORATION OF DROUGHT CONDITIONS APPEARS TO HAVE BEEN PREVENTED BY THE PERSISTENT PRESENCE OF AN AMPLIFIED UPSTREAM TROUGH OVER THE EAST-CENTRAL STATES. THIS IN TURN APPEARS TO BE RELATED TO THE INCORPORATION OF A WESTERN PACIFIC TYPHOON INTO THE WESTERLIES WELL UPSTREAM OF THE U.S. SINCE WE COULD SEE A SIMILAR SITUATION RECUR IN THE NEXT WEEK, IT IS DEEMED TOO RISKY TO FORECAST ANY BELOW-MEDIAN PRECIPITATION NEAR MOST OF THE GULF COAST AND SOUTHEAST. IN AREAS WHERE CLIMATE SIGNALS ARE WEAK AND/OR UNRELIABLE, EQUAL CHANCES (EC) OF BELOW-, NEAR-, AND ABOVE-MEDIAN PRECIPITATION AMOUNTS IS INDICATED.”
So what are these typhoons they are talking about? You can not tell from a daily snapshot but the level of activity in the Western Pacific has declined over the past week.
Well, how does a Tropical storm in the Western Pacific impact weather in the U.S. Midwest?
Here is an explanation related to a Western Pacific Typhoon that impacted the U.S. two years ago. The actual link can be found here.
“The following animations illustrate the evolution of a large-scale atmospheric wave pattern in response to the recurving of Tropical Storm Maliksi in the Northwest Pacific Ocean. Both animations depict the evolution of the wave pattern every 24 hours beginning at 8:00PM Eastern Time on 2 October 2012 and ending at 8:00PM Eastern Time on 5 October 2012. The first animation shows the region from 5 degrees south to 75 degrees north, and from 110 degrees east to 110 degrees west. The second animation shows the region from 5 degrees north to 75 degrees north, and from 150 degrees west to 40 degrees west. The North Pacific Ocean is in the center of the first animation, and the United States is in the center of the second animation.”
And here is Part 2 which overlaps Part 1 but extend across the U.S.
And more explanation:
“Perhaps some of you are still wondering how the displacement of atmospheric mass could contribute to the production of large-scale atmospheric waves? Remember, tropical cyclones, like any large-scale cyclone or small-scale cluster of thunderstorms, act to heat the upper troposphere and cool the lower troposphere. Thus, as part of the internal circulation of tropical cyclones, heat and mass near Earth’s surface are transported upward toward the top of the troposphere (while, to compensate for this upward transport, mass and cooler air from the upper-troposphere are transported toward the surface within and surrounding the tropical cyclone). Now, because this heat and mass cannot be pushed out into space (if you believe in the conservation of atmospheric mass, which you should), it eventually reaches a point where it can no longer be transported upward, and therefore has to be transported sideways (horizontally).
Recalling that the atmosphere is always trying to achieve stability, much of this horizontal transport of heat and mass will occur in the direction of lower temperatures (typically associated with higher latitudes). At the same time, to compensate for this transport of heat and mass toward colder regions, mass (and accompanying cold air) that originates in these colder regions will move in the direction of higher temperatures. Thus, to first-order, you have what appears to be an amplifying sine wave, with one part of the wave moving northward, and the other part of the wave moving southward. The atmospheric response to this displacement of mass is manifest in the formation of large-scale cyclones and associated circulations along these waves. This is how the atmosphere works toward achieving a more stable state, whereby the high latitudes (upper troposphere) are heated, while the low latitudes (lower troposphere) are cooled. This is science at its best.”
Now of course every storm is different but the above is a partial explanation of the term “teleconnections”.
I was going to discuss the PDO some more this week but I will consider the above to have fulfilled that part of my work plan for this week and instead just talk about today’s issued 6 – 14 day forecast and the latest on El Nino and call it an evening.
Todays 6 – 10 Day Outlooks.
Temperature Forecast for days 6 – 10:
6 – 10 Day Precipitation Forecast:
And now what they call Week Two which is days 8 – 14. Notice the overlap of days 8, 9, and 10. This reflects the difficulty of precisely timing the movement of highs (ridges) and lows (troughs) which is the primary mechanism for the development of these forecasts.
The 8 – 14 Day Temperature Forecast:
The 8- 14 Day Precipitation Forecast:
Resemblance between the 6 – 14 day outlook and the monthly NOAA August Outlook especially with regards to precipitation is not obvious (but of course days 6 -14 represent less than a third of a month) and to me indicates some confusion at NOAA as to what is going on. You can perhaps detect that in the follow excerpts from the 6 – 14 day outlook they released today (bold type is my emphasis) and it is more obvious in the discussion from the Monthly Outlook that I have excerpted above….and this is only four days later. My take is that something strange is going on and they do not fully understand it.
And here are some excepts from the discussion.
“6-10 DAY OUTLOOK FOR AUG 10 – 14 2014
THERE IS FAIRLY GOOD AGREEMENT AMONG TODAY’S MODEL SOLUTIONS FOR THE MEAN 500-HPA HEIGHTS OVER NORTH AMERICA AND VICINITY DURING THE 6-10 DAY PERIOD. THE OFFICIAL 500-HPA HEIGHT MANUAL BLEND REVEALS AN ANOMALOUS RIDGE/TROUGH PATTERN FROM WEST TO EAST ACROSS THE CONUS, THOUGH AT LOW AMPLITUDE. THE MOST IMPRESSIVE UPPER-LEVEL FEATURE IS FORECAST OVER ALASKA WHERE AN IMPRESSIVE BLOCK IS ANTICIPATED IN THE MEAN, WITH A DEEP TROUGH CENTERED JUST SOUTH OF ALASKA AND POSITIVE HEIGHT ANOMALIES OF GREATER THAN 180M FORECAST NORTH OF THE STATE. AN ANOMALOUSLY DIFFLUENT FLOW IS FORECAST OVER FAR EASTERN CANADA AND THE NORTH ATLANTIC.
THE SURFACE TEMPERATURE OUTLOOK LARGELY FOLLOWS THE FORECAST HEIGHT ANOMALIES OVER THE CONUS, CONSISTENT WITH THE CALIBRATED GEFS AND BIAS-CORRECTED ECMWF TEMPERATURE TOOLS. SLIGHT PREFERENCE IS GIVEN TO THE ECMWF OVER THE GREAT LAKES, WHERE THE GEFS CALIBRATED TEMPERATURE SEEMS UNDULY INFLUENCED BY BELOW-NORMAL LAKE TEMPERATURES. A LARGE REGION FAVORING NEAR-NORMAL TEMPERATURES IS DEPICTED CENTERED OVER THE CENTRAL CONUS, WHERE FORECAST HEIGHT ANOMALIES ARE ESPECIALLY WEAK AND THERE IS LITTLE INDICATION OF ANY PROLONGED PERIOD IN WHICH AN ANOMALOUS AIR MASS WILL IMPACT THE REGION.”
THE PRECIPITATION OUTLOOK LEANS HEAVILY ON THE GEFS CALIBRATED PRECIPITATION TOOL, AUGMENTED BY A SUBJECTIVE LOOK AT THE ECMWF ENSEMBLE MEAN PRECIPITATION TOTALS. ENHANCED PROBABILITIES FOR ABOVE-MEDIAN RAINFALL ARE CENTERED OVER THE SOUTHEAST, COINCIDENT WITH THE INFERRED BAROCLINIC ZONE DEPICTED BY THE SURFACE TEMPERATURE OUTLOOK. THERE IS A SLIGHT TILT TOWARD BELOW-MEDIAN PRECIPITATION ALONG THE MID-ATLANTIC AND NORTHEAST COAST, WHERE ANOMALOUSLY HIGH MEAN SEA-LEVEL PRESSURE IS SUGGESTED BY THE WEAK RIDGING OVER EASTERN CANADA ASSOCIATED WITH THE AFOREMENTIONED DIFFLUENT FLOW FORECAST OVER THAT REGION. BELOW-MEDIAN PRECIPITATION IS FAVORED OVER MUCH OF THE WESTERN CONUS UNDER UPPER-LEVEL RIDGING AND NO APPRECIABLE SIGNALS FOR AN ENHANCED SOUTHWEST MONSOON.
8-14 DAY OUTLOOK FOR AUG 12 – 18 2014
CHANGES FROM THE 6-10 DAY OUTLOOK CONSIST OF A WESTWARD EXPANSION OF PROBABILITIES FAVORING BELOW-NORMAL TEMPERATURES ACROSS EAST-CENTRAL CONUS AND REDUCED PROBABILITIES IN THE PRECIPITATION OUTLOOK TO REFLECT GREATER UNCERTAINTY. ADDITIONALLY, PROBABILITIES FAVORING ABOVE-MEDIAN PRECIPITATION ARE INTRODUCED CENTERED OVER SOUTHERN NEVADA AND ARE LARGELY DUE TO A NORTHWEST SHIFT IN THE CLIMATOLOGICAL RAINFALL COINCIDING WITH THE MEAN RIDGE POSITION, WHICH IS ALSO SHIFTED NORTHWEST FROM ITS LONG-TERM MEAN.
It is a pretty plain vanilla forecast. No mention of El Nino impacts. No mention of intrusions from the Pacific typhoons and even an Alaska blocking pattern is mentioned. So that impact if any may be for more than 14 days in our future but with the Pacific typhoons dying down that may no longer be a significant factor.
Updated El Nino Information
El Niño indicators ease
Issued on Tuesday 29 July 2014
Despite the tropical Pacific Ocean being primed for an El Niño during much of the first half of 2014, the atmosphere above has largely failed to respond, and hence the ocean and atmosphere have not reinforced each other. As a result, some cooling has now taken place in the central and eastern tropical Pacific Ocean, with most of the key NINO regions returning to neutral values.
While the chance of an El Niño in 2014 has clearly eased, warmer-than-average waters persist in parts of the tropical Pacific, and the (slight) majority of climate models suggest El Niño remains likely for spring. Hence the establishment of El Niño before year’s end cannot be ruled out. If an El Niño were to occur, it is increasingly unlikely to be a strong event.
Given the current observations and the climate model outlooks, the Bureau’s ENSO Tracker has shifted to El Niño WATCH status. This means the chance of El Niño developing in 2014 is approximately 50%, which remains significant at double the normal likelihood of an event.
El Niño is often associated with wide scale below-average rainfall over southern and eastern inland areas of Australia and above-average daytime temperatures over southern Australia. Similar impacts prior to the event becoming fully established regularly occur.
The Indian Ocean Dipole (IOD) index has been below −0.4 °C (the negative IOD threshold) since mid-June, but needs to remain negative into August to be considered an event. Model outlooks suggest this negative IOD is likely to be short lived, and return to neutral by spring. A negative IOD pattern typically brings wetter winter and spring conditions to inland and southern Australia.
Now let us look at the latest from NOAA
You can not tell too much from this but clearly the Central Pacific has cooled which is not exactly the signature of an El Nino. But the Eastern Pacific remains warm. And it does appear that there may be more warm water coming. Also the cooling of the Central Pacific could easily have been predicted by looking at last week’s report as it is consistent with the upwelling phase of the Kelvin Wave that is passing through. So none of this is conclusive but it is not exactly what you would expect if a strong or even moderate El Nino was developing. That could still happen but those who are sticking with the 80% odds are really out on a limb.
I would not be surprised to see an announcement soon by NOAA that their level of confidence in this El Nino happening this winter has declined or a significant downgrading of the predicted strength and impact of this event. The next NOAA Seasonal Weather Outlook on August 21 should be pretty interesting as it is based quite a bit on the El Nino assumption.
A Few Thoughts on the North American Monsoon
The following map is the mid-atmosphere 7-Day chart rather than the surface highs and lows and weather features. In some cases it provides a clearer and less confusing picture as it shows the major pressure gradients – after all, the weather takes place above the ground not at ground level (fog excluded).
Notice the “Four Corner’s High”as of today’s forecast i.e. August 5, for a week from now (the graphic is about Day 7) does not appear to be located in a bad position to draw in moisture from the Gulf of Mexico which right now may be too far to the east to be accessible and the Four Corners High circulation is in a less ideal position for drawing in moisture from the Gulf of California. The 6 – 14 day Outlook appears to be suggesting that the Southwest Monsoon will be taking a bit of a hiatus except for Nevada: not sure how that gets implemented. We will see how things work out as there are many moving pieces right now and it is difficut to put it all together.