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Pattern ENSO Updates

Even after several weeks of strong trades east of the dateline, all it took was a momentary lapse over the past week and change, and now the downwelling kelvin wave over the CP is having little trouble infiltrating into the eastern boundary region, expect the NINO 1-2 & NINO 3 regions to warm quite a bit in early June. When your base state is characterized by strong-very strong easterly trade winds and you even a have a momentary hiccup to upset the wind-gravity balance, that could be enough to flip the ENSO state especially if there's already some pre-existing momentum in place like there was here. I still like the chances of a weak-moderate El Nino developing for this upcoming winter, the odds are probably at least double climatology (> 60-65%)

wkxzteq_anm.gif
 
Even after several weeks of strong trades east of the dateline, all it took was a momentary lapse over the past week and change, and now the downwelling kelvin wave over the CP is having little trouble infiltrating into the eastern boundary region, expect the NINO 1-2 & NINO 3 regions to warm quite a bit in early June. When your base state is characterized by strong-very strong easterly trade winds and you even a have a momentary hiccup to upset the wind-gravity balance, that could be enough to flip the ENSO state especially if there's already some pre-existing momentum in place like there was here. I still like the chances of a weak-moderate El Nino developing for this upcoming winter, the odds are probably at least double climatology (> 60-65%)

The subsurface seems to be slowly rewarming. If this continues for a few more weeks, it is liable to exceed +1.0 C by mid summer. This would be a strong indicator that a weak to moderate El Niño peak in late fall or winter has a good chance. Otoh, that May Eurosip map suggests to me that the ONI (trimonthly) would very likely not reach +0.5 until after ASO.
 
The subsurface seems to be slowly rewarming. If this continues for a few more weeks, it is liable to exceed +1.0 C by mid summer. This would be a strong indicator that a weak to moderate El Niño peak in late fall or winter has a good chance. Otoh, that May Eurosip map suggests to me that the ONI (trimonthly) would very likely not reach +0.5 until after ASO.

Indeed, this morning's weekly update has the OHC now up to a new high for this season of +0.94. That in itself tells me the odds are increasing for a weak to moderate Modoki El Niño peak late fall or more likely winter. However, the May Eurosip ASO forecast of only warm neutral tells me to expect any El Niño, should it occur, to be late in starting based on ONI since the May Eurosip has had a history of a warm bias. This is going to be interesting to follow.

The weekly 3.4 update had no change and is still at -0.1.
 
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The weekly update for 3.4 has it slightly warmer at 0.0. The OHC rose from +0.94 to +1.01, a pretty notable rise considering these already solidly warm levels.
The MAM ONI came in at -0.4.
 
Warmest May OHC anomaly back to 1979/Later ENSO peak/May SOI

+2.01 1997/ lead to strong El Nino/ May SOI: -19.0
+1.53 2015/ lead to strong El Nino/ May SOI: -13.1
+1.14 1980/ El Nino fail/neutral/ May SOI: -2.6
+0.96 1982/ lead to strong El Nino/ May SOI: -7.1
+0.95 2014/ lead to weak El Nino/ May SOI: +4.3
+0.89 2018/ ???????????????/ May SOI: +2.7
+0.87 2009/ lead to strong El Nino/ May SOI: -5.0
+0.76 1991/ lead to strong El Nino/ May SOI: -17.9
+0.61 1989/ warmed only to neutral/ May SOI: +15.1
+0.58 1987/ lead to strong El Nino/ May SOI: -19.6
+0.54 2006/ lead to weak El Nino/ May SOI: -7.7

So, 8 of the 10 (80%) of the surrounding years were El Nino by late in the year. The two that failed had a May SOI of -2.6 (1980) and +15.1 (1989). Of the 7 that had a May SOI -5.0 or lower, 6 went onto a strong Nino peak and one went only to a weak El Nino peak. None of the 3 that were higher than -5.0 went to a moderate or stronger El Nino. This all tells me that the chance for strong El Nino by winter remains low, but the chance for weak (to perhaps moderate) El Nino is increasing. However, I still think ASO will only be warm neutral based on the warm biased Eurosip, which in May forecasted warm neutral for ASO.
 
I just noticed something quite interesting about the May, 2018, pressures at Tahiti and Darwin:

Darwin monthly SLP: http://www.cpc.ncep.noaa.gov/data/indices/darwin

Tahiti monthly SLP: http://www.cpc.ncep.noaa.gov/data/indices/tahiti

- Tahiti's May, 2018, SLP, which was 1014.1, was the highest on record back to 1951! The normal is only 1012.7. The four highest on record preceding El Nino were 1013.9 (2014 and 1976) followed by 13.7 (2004) and 13.3 (1979), all 4 weak Ninos.
- However, Darwin's was also above normal with its 1012.2. Only 9 of the prior 67 years had higher and 3 were the same. The four cited weak Nino years all had lower Darwin pressures ranging from 10.6 to 12.0. That's why all 4 of those years had a +SOI in May.
- All of the above along with the latest Eurosip for ASO being only warm neutral tells me that any 2018-9 El Nino, which is strongly hinted at by the current +1.01 OHC, would likely be weak to low end moderate.
 
I wouldn't get too caught up over the Eurosip forecast NINO bias, but it's better to look at the large-scale conditions rather than focus on the bias of the model forecasting those conditions because the latter is ridden w/ far more uncertainty and unknowns.
In other news, this guy is a prime example of why you don't want to get caught in windshield wiper mode during every sub seasonal forcing change in the Eq Pacific. The integrated effect of several MJO events over a period of several months is what really matters and this favors weak El Nino regardless of whether we somehow get a few weeks of stronger than normal trades (which is normal btw), or the noisy southern oscillation index for a particular month or two is of "x" value.

Screen Shot 2018-06-04 at 7.22.06 PM.png
Screen Shot 2018-06-04 at 7.17.22 PM.png
 
Nino 3.4 held at 0.0.

Per yesterday's Euro runs largely averaged out and adjusted for biases, here's my rough SOI projections for the next 10 days:
6/11: -26
6/12: -28
6/13: -9
6/14: +1
6/15: 0
6/16: -7
6/17: -13
6/18: -17
6/19: -13
6/20: -9

Based on this, I'm guessing the 6/1-20 SOI will be near -8 and will mean June as a whole has a pretty high chance to end up negative and a pretty good chance to end up sub -5. That would be pretty supportive of a later in the year weak to low end moderate El Nino based on history back to the late 1800s and especially when considering the subsurface now being near or warmer than +1.0.

I'm projecting Tahiti to be in or near the 1014-1014.25 range and Darwin to be in or near the 1014.3-1014.7 range for 6/1-20. Consider these stats:

Avg June Darwin SLP minus 1000: 13.0
Avg June Tahiti SLP minus 1000: 13.7

Avg June Darwin SLP minus 1000 strong Nino: 13.5
Avg June Darwin SLP minus 1000 wk-mod Nino: 13.0
Avg June Darwin SLP minus 1000 weak Nina: 13.0
Avg June Darwin SLP minus 1000 mod-str Nina: 12.8

Avg June Tahiti SLP minus 1000 strong Nino: 12.8
Avg June Tahiti SLP minus 1000 wk-mod Nino: 13.5
Avg June Tahiti SLP minus 1000 weak Nina: 14.2
Avg June Tahiti SLP minus 1000 mod-str Nina: 14.1

So, the Darwin SLP appears on the way to above normal for June with Tahiti slightly above. Actually, there have been only 3 Junes with Darwin SLP higher than 1014 mb since 1950: 2004 (preceded weak El Nino), 1997 (preceded SEN), and 1965 (preceded SEN). So, Darwin, alone, favors El Nino.

Have there been any Tahiti Junes in the high 1013s or higher that preceded El Nino? Actually, there have been a pretty good number but mainly weak: 1965 SEN (1013.7), 1968 MEN (1014.9), 1969 WEN (1013.8), 1976 WEN (1013.8), 1979 WEN (1014.5), 1991 SEN (1013.8), 2004 WEN (1013.7), and 2006 WEN (1013.8).

Conclusion: I'm leaning toward a late oncoming (after ASO in deference to the Eurosip May Nino 3.4 forecast for ASO being only warm neutral) weak to low end moderate El Nino this year.

*Edit: The 6/11 daily SOI should have been released by now. Maybe they're on vacation.
 
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Nino 3.4 warmed to 0.2 C. And CPC issued a El Niño Watch.

Thanks. However, note that despite the 0.2 warming in Niño 3.4, the upper OHC actually cooled a bit to +0.82 after having been near +1.0 in late May. So, perhaps that means any further warming over the next couple of months will be slow overall. I’m still thinking only warm neutral for ASO (based largely on the warm biased May Eurosip being only at warm neutral for ASO) followed by warming to weak to low end moderate El Niño later in fall to winter.
 
Thanks. However, note that despite the 0.2 warming in Niño 3.4, the upper OHC actually cooled a bit to +0.82 after having been near +1.0 in late May. So, perhaps that means any further warming over the next couple of months will be slow overall. I’m still thinking only warm neutral for ASO (based largely on the warm biased May Eurosip being only at warm neutral for ASO) followed by warming to weak to low end moderate El Niño later in fall to winter.

It was hardly above +0.9 and barely dropped to +0.8, we had a larger drop in April and that really didn't mean much. It's not going to make that much of a difference in the grand scheme of things, I wouldn't delve too much into it, especially when there's been more WWBs.
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It was hardly above +0.9 and barely dropped to +0.8, we had a larger drop in April and that really didn't mean much. It's not going to make that much of a difference in the grand scheme of things, I wouldn't delve too much into it, especially when there's been more WWBs.
View attachment 5380


Eric,
The OHC graph within the 6/4/18 report did actually show near +1.0 as per this post:
http://southernwx.com/community/threads/enso-updates.146/page-16#post-101602

CPC has since cooled it back some for that period in each of the subsequent two weekly releases, but it was showing near +1.0 then.

Regardless of exactly how much it has cooled back, it has cooled a small amount and I'm sticking with my prediction that the ASO trimonth will be warm neutral (cooler than +0.5) based largely on the May Eurosip being only warm neutral for ASO. During 2005-17 it never missed a category to the cool side. The average miss was a whopping +0.5, a very significant warm bias. I'm expecting ONI based El Nino to start during the SON trimonth or later.

What are you predicting for the ASO trimonth for Nino 3.4?

Regardless of my prediction of only warm neutral for ASO, I still expect the tropics to be affected negatively by the anticipated oncoming El Nino
 
Eric,
The OHC graph within the 6/4/18 report did actually show near +1.0 as per this post:
http://southernwx.com/community/threads/enso-updates.146/page-16#post-101602

CPC has since cooled it back some for that period in each of the subsequent two weekly releases, but it was showing near +1.0 then.

Regardless of exactly how much it has cooled back, it has cooled a small amount and I'm sticking with my prediction that the ASO trimonth will be warm neutral (cooler than +0.5) based largely on the May Eurosip being only warm neutral for ASO. During 2005-17 it never missed a category to the cool side. The average miss was a whopping +0.5, a very significant warm bias. I'm expecting ONI based El Nino to start during the SON trimonth or later.

What are you predicting for the ASO trimonth for Nino 3.4?

Regardless of my prediction of only warm neutral for ASO, I still expect the tropics to be affected negatively by the anticipated oncoming El Nino
Where are you getting +1.01C from because it’s not listed in the CPCs weekly report? If you're just eyeballing it then that doesn't count, it certainly seems to have barely ticked above +0.9C. Regardless you have to keep in mind that the GODAS analysis the CPC uses is often much different than the actual data provided by the TAO buoys, a change of a tenth or two degrees C is well within the understood error range of this product. I think you’re overreacting to this apparent downturn in OHC.
 
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Where are you getting +1.01C from because it’s not listed in the CPCs weekly report? If you're just eyeballing it then that doesn't count, it certainly seems to have barely ticked above +0.9C. Regardless you have to keep in mind that the GODAS analysis the CPC uses is often much different than the actual data provided by the TAO buoys, a change of a tenth or two degrees C is well within the understood error range of this product. I think you’re overreacting to this apparent downturn in OHC.

A quarter to a third of degree C (0.33) is well within the understood error range for this product, you only have to look so far as to other ocean models published by ECMWF, JMA, and the BOM to see that this apparent change in the CPC's GODAS product isn't significant or arguably even measurable.
teq_glb_xz_L1.gif

ohc_nino3_4yr.gif
 
Where are you getting +1.01C from because it’s not listed in the CPCs weekly report? If you're just eyeballing it then that doesn't count, it certainly seems to have barely ticked above +0.9C. Regardless you have to keep in mind that the GODAS analysis the CPC uses is often much different than the actual data provided by the TAO buoys, a change of a tenth or two degrees C is well within the understood error range of this product. I think you’re overreacting to this apparent downturn in OHC.

Yes, it was eyeballing. Also, it actually was showing warmer (near +1.0) in the 6/4 report though the 6/11 report wasn't quite as warm and the 6/18 report was even a little cooler.For whatever reason, they often modify earlier periods.

It is Eurosip that is what I had last month based my ASO prediction on. At the time, OHC was rising toward new seasonal highs. The recent slight OHC cooldown came well after that prediction.
What are you predicting for ASO?
 

HOME> Outlook Maps>Seasonal Forecast Discussion

PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830 AM EDT THU JUN 21 2018

SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS

THE JULY-AUGUST-SEPTEMBER (JAS) 2018 TEMPERATURE OUTLOOK FAVORS ABOVE-NORMAL
TEMPERATURES ACROSS A MAJORITY OF THE FORECAST DOMAIN, ALTHOUGH EQUAL CHANCES
OF BELOW-, NEAR-, OR ABOVE-NORMAL TEMPERATURES ARE FORECAST ACROSS THE NORTHERN
GREAT PLAINS AND UPPER MISSISSIPPI VALLEY. THE HIGHEST PROBABILITIES FOR
ABOVE-NORMAL TEMPERATURES ARE FORECAST ACROSS PARTS OF THE GREAT BASIN AND
PACIFIC NORTHWEST. THE JAS 2018 PRECIPITATION OUTLOOK FEATURES ENHANCED ODDS
FOR ABOVE NORMAL PRECIPITATION ACROSS THE MID-ATLANTIC AND EXTENDING FROM
SOUTHERN CALIFORNIA AND THE DESERT SOUTHWEST NORTHEAST TO THE GREAT BASIN AND
CENTRAL ROCKIES. INCREASED CHANCES FOR ABOVE NORMAL PRECIPITATION ARE ALSO
FORECAST ACROSS MAINLAND ALASKA AND THE ALEUTIANS. BELOW-NORMAL PRECIPITATION
IS FAVORED ACROSS THE WESTERN GULF COAST, LOWER MISSISSIPPI VALLEY, AND PACIFIC
NORTHWEST.

DURING THE FALL AND WINTER 2018-19, THE TEMPERATURE AND PRECIPITATION OUTLOOKS
ARE CONSISTENT WITH INCREASING ODDS OF EL NINO DEVELOPMENT AND ITS TYPICAL
INFLUENCES. CHANCES FOR ABOVE NORMAL PRECIPITATION HAVE INCREASED ACROSS THE
SOUTHERN TIER OF THE CONUS, COMPARED TO PREVIOUS OUTLOOKS. ODDS FOR ABOVE
NORMAL TEMPERATURES CONTINUE TO INCREASE DURING THE WINTER 2018-19, FROM THE
PACIFIC NORTHWEST EAST TO THE NORTHERN GREAT PLAINS AND UPPER MISSISSIPPI
VALLEY.

EQUAL CHANCES (EC) ARE FORECAST IN AREAS WHERE THE LIKELIHOOD OF SEASONAL MEAN
TEMPERATURES OR SEASONAL ACCUMULATED PRECIPITATION AMOUNTS ARE EXPECTED TO BE
SIMILAR TO CLIMATOLOGICAL PROBABILITIES.

BASIS AND SUMMARY OF THE CURRENT LONG-LEAD OUTLOOKS
NOTE: FOR GRAPHICAL DISPLAYS OF THE FORECAST TOOLS DISCUSSED BELOW SEE:
HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/90DAY/TOOLS/BRIEFING

CURRENT ATMOSPHERIC AND OCEANIC CONDITIONS

OCEANIC AND ATMOSPHERIC OBSERVATIONS ACROSS THE EQUATORIAL PACIFIC INDICATE
ENSO-NEUTRAL CONDITIONS PERSISTED THROUGH MAY. THE OBSERVED WEEKLY SSTS,
CENTERED ON JUNE 13, FEATURE POSITIVE ANOMALIES OF MORE THAN 0.5 DEGREE C FROM
140-100 DEGREES W AND ALSO WEST OF THE DATE LINE. POSITIVE SUBSURFACE
TEMPERATURE ANOMALIES (AVERAGED ACROSS 180-100 DEGREES W) CONTINUED TO
INCREASE, DUE TO ANOTHER DOWNWELLING OCEANIC KELVIN WAVE.

OUTGOING LONGWAVE RADIATION (OLR) ANOMALIES INDICATED SUPPRESSED CONVECTION
FROM PAPUA NEW GUINEA EAST TO THE CENTRAL EQUATORIAL PACIFIC OCEAN FROM MAY 18
TO JUNE 12. THE WIND ANOMALIES AT THE LOWER AND UPPER-LEVELS WERE NEAR AVERAGE
ACROSS THE EQUATORIAL PACIFIC. THESE ATMOSPHERIC INDICATORS ARE CONSISTENT WITH
ENSO NEUTRAL CONDITIONS.


PROGNOSTIC DISCUSSION OF SST FORECASTS

THE CPC SST CONSOLIDATION (CON) FOR THE NINO 3.4 REGION INDICATES AN INCREASE
IN ANOMALIES TO +0.5 DEGREES C BY SON WITH POSITIVE ANOMALIES PEAKING CLOSER TO
1.0 DEGREES C DURING NDJ AND DJF 2018-19. THE SST CONSTRUCTED ANALOG AND MARKOV
MODEL INDICATE PEAK ANOMALY VALUES GREATER THAN 1.0 C THIS UPCOMING WINTER. THE
CPC/IRI CONSENSUS FORECAST FAVORS THE ONSET OF EL NINO DURING THE NORTHERN
HEMISPHERE FALL WITH PROBABILITIES OF EL NINO ABOVE 60 PERCENT FROM NDJ 2018-19
JFM 2019.

PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS

THE INCREASING LIKELIHOOD OF EL NINO DEVELOPMENT CONTINUES TO PLAY A MAJOR
FACTOR IN THE FALL AND WINTER 2018-19 OUTLOOKS. TOOLS USED FOR THE SEASONAL
OUTLOOKS INCLUDED DYNAMICAL MODEL FORECAST GUIDANCE SUCH AS THE NORTH AMERICAN
MULTI-MODEL ENSEMBLE (NMME), THE ENSO-OCN STATISTICAL MODEL, THE SST
CONSTRUCTED ANALOG MODEL, AND EL NINO COMPOSITES. A RELATIVELY NEW TOOL IN OUR
SUITE IS THE CBAM TOOL, OR CALIBRATION, BRIDGING, AND MERGING FORECAST TOOL.
THIS USES A BAYESIAN APPROACH TO THE NMME MODEL CONSOLIDATION AS WELL AS A
HYBRIDIZATION WHEREIN EACH CONSTITUENT MODEL'S NINO 3.4 FORECAST IS 'BRIDGED'
TO THE PREDICTAND VIA LINEAR REGRESSION. THE OUTLOOKS DURING THE 2019 WARM
SEASON WERE BASED PRIMARILY ON DECADAL TRENDS.

PROGNOSTIC DISCUSSION OF OUTLOOKS - JAS 2018 TO JAS 2019

TEMPERATURE

ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE CONUS AND ALASKA DURING
JAS WITH THE HIGHEST PROBABILITIES FORECAST ACROSS THE GREAT BASIN AND PACIFIC
NORTHWEST, BASED ON EXCELLENT AGREEMENT AMONG TOOLS INCLUDING A STRONG DECADAL
SIGNAL. PROBABILITIES FOR ABOVE NORMAL TEMPERATURES WERE REDUCED ACROSS THE
SOUTHWEST FROM THE PREVIOUS OUTLOOK DUE TO INCREASING FORECAST CONFIDENCE IN A
WETTER PATTERN. ABOVE NORMAL TEMPERATURES ARE FAVORED TO INCLUDE MORE OF THE
SOUTH-CENTRAL U.S. DURING JAS, COMPARED TO LAST MONTH, WITH THE CONSIDERATION
OF LOW SOIL MOISTURE TO START THE OUTLOOK PERIOD ACROSS THE OZARKS REGION, A
DRIER TREND IN THE SEASONAL TOOLS, AND CONSISTENCY WITH THE JULY TEMPERATURE
OUTLOOK. ALSO, THE IMME INDICATES POSITIVE TEMPERATURES ANOMALIES FOR THE
MIDDLE MISSISSIPPI VALLEY DURING THIS TIME PERIOD. EQUAL CHANCES FOR BELOW-,
NEAR-, OR ABOVE-NORMAL TEMPERATURES ARE FORECAST FOR THE NORTHERN GREAT PLAINS
AND UPPER MISSISSIPPI VALLEY WHERE FORECAST CONFIDENCE IS LOWEST.

THE INCREASING CHANCES FOR EL NINO DEVELOPMENT WERE A FACTOR IN THE TEMPERATURE
OUTLOOK, BEGINNING IN THE FALL AND BECOMING MORE PROMINENT DURING THE WINTER
2018-19. BASED ON EL NINO COMPOSITES, PROBABILITIES FOR ABOVE NORMAL
TEMPERATURES WERE INCREASED ACROSS MUCH OF MAINLAND ALASKA AND ALONG THE
NORTHERN TIER OF THE CONUS WITH A DECREASE IN THE COVERAGE OF ABOVE NORMAL
TEMPERATURES THROUGHOUT THE SOUTHERN TIER OF THE CONUS. AN EXPECTED LACK OF SEA
ICE ELEVATES CHANCES FOR ABOVE NORMAL TEMPERATURES ACROSS NORTHERN ALASKA
DURING THE FALL SEASON. THE TEMPERATURE OUTLOOK AT THE LONGER LEAD TIMES IS
BASED LARGELY ON TRENDS.

PRECIPITATION

THE PRECIPITATION OUTLOOKS ARE BASED ON THE LATEST DYNAMICAL MODEL GUIDANCE,
THROUGH NDJ, ALONG WITH THE TYPICAL INFLUENCES FROM EL NINO DURING THE FALL AND
WINTER 2018-19. COMPARED TO THE PREVIOUS OUTLOOK FOR JAS, ODDS FOR ABOVE NORMAL
PRECIPITATION WERE EXPANDED TO INCLUDE MORE OF THE DESERT SOUTHWEST AND
SOUTHERN CALIFORNIA. THIS IS CONSISTENT WITH THE NMME AND POTENTIAL RAINFALL
ASSOCIATED WITH EAST PACIFIC TROPICAL CYCLONES, WHICH ARE MORE LIKELY TO AFFECT
THESE AREAS DURING A DEVELOPING EL NINO. THE LATEST PRECIPITATION TOOLS,
INDICATE LITTLE TO NO SUPPORT FOR THE INCREASED CHANCES OF BELOW NORMAL
PRECIPITATION FOR FLORIDA, SO THAT WAS REMOVED FROM THE PREVIOUS OUTLOOK. THE
NMME INDICATES RELATIVELY HIGH ODDS FOR BELOW NORMAL PRECIPITATION EXTENDING
FROM THE CARIBBEAN REGION WEST TO THE GULF OF MEXICO AND MUCH OF TEXAS AND THE
LOWER MISSISSIPPI VALLEY. THEREFORE, INCREASED CHANCES FOR BELOW NORMAL
PRECIPITATION WERE INTRODUCED TO PARTS OF TEXAS AND THE LOWER MISSISSIPPI
VALLEY FOR JAS. PRECIPITATION TOOLS REMAINED CONSISTENT FEATURING ENHANCED ODDS
FOR ABOVE (BELOW) NORMAL PRECIPITATION ACROSS PARTS OF THE EASTERN U.S.
(PACIFIC NORTHWEST) AND A RELATIVELY WET PATTERN FOR MUCH OF ALASKA.

EL NINO PRECIPITATION COMPOSITES WERE RELIED UPON IN THE OUTLOOKS DURING THE
FALL AND WINTER SEASONS WHEN ABOVE-NORMAL PRECIPITATION BECOMES MORE LIKELY
ACROSS THE SOUTHWEST, SOUTHERN GREAT PLAINS, GULF COAST STATES, AND SOUTHEAST.
THE STRONGEST WET SIGNAL EXISTS ACROSS FLORIDA DURING NDJ AND DJF, WHILE A DRY
SIGNAL EXISTS FROM THE GREAT LAKES SOUTH TO THE OHIO VALLEY DURING JFM AND FMA.
THE PRECIPITATION OUTLOOK ACROSS ALASKA DURING THE FALL AND WINTER IS
CONSISTENT WITH THE SST CONSTRUCTED ANALOG.

AT THE LONGER LEADS, MJJ THROUGH JAS 2019, THE TILT IN THE ODDS TOWARDS ABOVE
NORMAL PRECIPITATION ACROSS PARTS OF THE CENTRAL AND EASTERN U.S. IS CONSISTENT
WITH TRENDS. ALSO, THE FAVORED AREA FOR BELOW-MEDIAN PRECIPITATION ACROSS THE
NORTHWESTERN CONUS DURING THESE OUTLOOK PERIODS IS RELATED TO TRENDS.

FORECASTER: BRAD PUGH

THE CLIMATIC NORMALS ARE BASED ON CONDITIONS BETWEEN 1981 AND 2010, FOLLOWING
THE WORLD METEROLOGICAL ORGANIZATION CONVENTION OF USING THE MOST RECENT 3
COMPLETE DECADES AS THE CLIMATIC REFERENCE PERIOD. THE PROBABILITY ANOMALIES
FOR TEMPERATURE AND PRECIPITATION BASED ON THESE NEW NORMALS BETTER REPRESENT
SHORTER TERM CLIMATIC ANOMALIES THAN THE FORECASTS BASED ON OLDER NORMALS.

FOR A DESCRIPTION OF OF THE STANDARD FORECAST TOOLS - THEIR SKILL- AND THE
FORECAST FORMAT PLEASE SEE OUR WEB PAGE AT
HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/LONG_RANGE/TOOLS.HTML
(USE LOWER CASE LETTERS)
INFORMATION ON THE FORMATION OF SKILL OF THE CAS FORECASTS MAY BE FOUND AT:
HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/SOILMST_MONITORING/US/OUTLOOK/OUTLOOK.SHTM
L
(USE LOWERCASE LETTERS)
NOTES - THESE CLIMATE OUTLOOKS ARE INTENDED FOR USE PRIOR TO THE START OF THEIR
VALID PERIOD. WITHIN ANY GIVEN VALID PERIOD OBSERVATIONS AND SHORT AND MEDIUM
RANGE FORECASTS SHOULD BE CONSULTED.

THIS SET OF OUTLOOKS WILL BE SUPERSEDED BY THE ISSUANCE OF THE NEW SET NEXT
MONTH ON JUL 19 2018


1981-2010 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE W
 
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