PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK 
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 
830AM EDT THURSDAY JUL 17 2014 
 
30-DAY OUTLOOK DISCUSSION FOR AUGUST 2014 
 
RECENT OCEANIC CONDITIONS ACROSS THE TROPICAL PACIFIC CONTINUE TO SUPPORT THE 
FAVORED TRANSITION FROM ENSO-NEUTRAL TO EL NINO LATER THIS SUMMER. HOWEVER, THE 
ATMOSPHERE REMAINS SOMEWHAT DECOUPLED WITH THE RELATIVELY WARM SEA SURFACE 
TEMPERATURES (SST) AND THE SUBSURFACE WARMTH OF THE TROPICAL PACIFIC. THESE 
OBSERVATIONS SUGGESTS THAT THE ENSO PHASE IS STILL NEUTRAL. IT NOW APPEARS THAT 
THE PREDICTED EL NINO MAY PEAK AT WEAK TO MODERATE STRENGTH BY LATE 
AUTUMN/EARLY WINTER, COMPARED TO PREVIOUS EXPECTATIONS OF FAVORED MODERATE 
INTENSITY PEAKING DURING THE SAME PERIOD. 
 
DURING THE PAST FEW WEEKS, POSITIVE SST ANOMALIES PERSISTED (THOUGH WEAKENED 
SLIGHTLY) IN THE EASTERN EQUATORIAL PACIFIC, AND ANOMALIES ARE CLOSE TO ZERO IN 
THE CENTRAL PACIFIC (180W-150W). THE LATEST WEEKLY SST DEPARTURE IN THE 
EAST-CENTRAL PACIFIC (NINO 3.4 REGION) IS +0.3C. THE OCEANIC HEAT CONTENT 
(SUBSURFACE TEMPERATURE ANOMALIES IN THE UPPERMOST 300-METERS OF THE EASTERN 
AND CENTRAL EQUATORIAL PACIFIC) DECLINED FAIRLY RAPIDLY IN THE LAST FEW MONTHS, 
AND ANOMALIES ARE NOW CLOSE TO ZERO. DURING THIS SAME PERIOD, THE LARGE 
RESERVOIR OF SUBSURFACE WARMTH OVER THE CENTRAL AND EASTERN EQUATORIAL PACIFIC 
HAS DIMINISHED SIGNIFICANTLY IN COVERAGE AND MAGNITUDE, AND IS NOW CONFINED 
FROM ABOUT 145W-85W, AND EXTENDS DOWN TO A DEPTH OF ABOUT 75 METERS. DURING THE 
PAST 30-DAYS, TROPICAL RAINFALL WAS SLIGHTLY ABOVE-AVERAGE IN INDONESIA AND THE 
WESTERN EQUATORIAL PACIFIC, AND LOW-LEVEL (850-HPA) WINDS WERE NEAR LONG-TERM 
AVERAGES ACROSS MOST OF THE EQUATORIAL PACIFIC. 
 
MONTHLY MEAN TEMPERATURES FOR AUGUST 2014 ARE FAVORED TO BE ABOVE-NORMAL ACROSS 
THE SOUTHERN HALVES OF BOTH THE LOWER GREAT PLAINS AND MISSISSIPPI VALLEY, THE 
SOUTHEAST, TENNESSEE VALLEY, AND MUCH OF THE MID-ATLANTIC REGION, AS WELL AS IN 
THE PACIFIC NORTHWEST, MOST OF NEVADA AND CALIFORNIA, AND ALASKA. BELOW-NORMAL 
MONTHLY MEAN TEMPERATURES ARE MOST LIKELY OVER PORTIONS OF THE NORTHERN GREAT 
PLAINS, UPPER MISSISSIPPI VALLEY, AND UPPER GREAT LAKES REGION. THIS OUTLOOK IS 
BASED PRIMARILY ON RECENT RUNS OF THE CFS DYNAMICAL MODEL, NMME, IMME, AND 
THEIR CONSTITUENT CLIMATE MODELS. IT IS ALSO BASED ON, TO A LESSER DEGREE, THE 
CAS, SMLR, CCA, AND OCN STATISTICAL TOOLS, AS WELL AS SOIL MOISTURE 
CONSIDERATIONS. AREAS OF DIMINISHED CONFIDENCE INCLUDE THE FOUR CORNERS MONSOON 
REGION (WHERE THE CFS IN PARTICULAR PREDICTS ENHANCED ODDS OF BELOW-NORMAL 
TEMPERATURES, AS OPPOSED TO THE EUROPEAN AND OTHER CLIMATE MODELS WHICH FAVOR 
NEAR OR EVEN ABOVE-NORMAL TEMPERATURES), AND NORTHERN ALASKA. IN THIS LATTER 
AREA, RECENT RUNS OF THE CFS APPEAR TO BE TOO COLD, ESPECIALLY GIVEN THE 
ANOMALOUSLY LOW ICE COVER OBSERVED OVER THE BEAUFORT SEA. IN AREAS WHERE 
CLIMATE SIGNALS ARE WEAK AND/OR UNRELIABLE, EQUAL CHANCES (EC) OF BELOW-, 
NEAR-, AND ABOVE-NORMAL MONTHLY MEAN TEMPERATURES IS INDICATED. 
 
PRECIPITATION FOR AUGUST 2014 IS ANTICIPATED TO BE ABOVE-MEDIAN OVER MUCH OF 
THE INTERIOR WEST. BELOW-MEDIAN PRECIPITATION AMOUNTS ARE SLIGHTLY FAVORED FOR 
MOST OF THE GULF COAST REGION, AND PORTIONS OF GEORGIA AND SOUTH CAROLINA. 
THE OUTLOOK IS BASED PRIMARILY ON THE SAME TOOLS NOTED ABOVE FOR TEMPERATURE. 
FOR THE SOUTHWEST, IT IS CONSISTENT WITH THE EXPECTATION OF BOTH AN ENHANCED 
MONSOON AND AN ENHANCED EASTERN PACIFIC HURRICANE SEASON. IN THE NORTHERN HIGH 
PLAINS AND NORTHERN ROCKIES, IT IS MOST LIKELY DUE TO FRONTAL ACTIVITY. PERHAPS 
THE MOST UNCERTAIN PART OF THIS FORECAST IS THE ANTICIPATED REGION OF FAVORED 
BELOW-MEDIAN RAINFALL OVER THE GULF COAST STATES AND ADJACENT PORTIONS OF 
GEORGIA AND SOUTH CAROLINA. THE CFS AND IMME SUPPORT SOME EXTENSION OF THIS 
AREA OF RELATIVE DRYNESS THROUGH NORTH CAROLINA AND PARTS OF THE MID-ATLANTIC 
REGION, WHILE THE NMME INCLUDES ONLY TEXAS AND LOUISIANA. THIS IS COMPLICATED 
BY WHAT APPEARS TO BE THE EARLY STAGES OF A FLASH DROUGHT TRYING TO DEVELOP 
FROM ALABAMA AND THE FLORIDA PANHANDLE NORTHEASTWARD INTO SOUTHWESTERN 
VIRGINIA. THE PRECIPITATION FORECAST FOR THE UPCOMING 7-DAYS CALLS FOR 
SIGNIFICANT RAINFALL (RANGING FROM 0.5 TO 4 INCHES) TO OCCUR ACROSS THE GULF 
COAST REGION AND SOUTHEAST, WHICH MAY (AT LEAST TEMPORARILY) HELP TO OFFSET THE 
RAPIDLY DETERIORATING SOIL MOISTURE CONDITIONS NOW SETTING UP IN THE SOUTHEAST. 
THE OFFICIAL CPC PRECIPITATION OUTLOOK IS THOUGHT TO BE A REASONABLE COMPROMISE 
BETWEEN VARIOUS COMPETING FACTORS. IN AREAS WHERE CLIMATE SIGNALS ARE WEAK 
AND/OR UNRELIABLE, EQUAL CHANCES (EC) OF BELOW-, NEAR-, AND ABOVE-MEDIAN 
PRECIPITATION AMOUNTS IS INDICATED. 
 
THE MAIN FACTORS THAT USUALLY INFLUENCE THE MONTHLY CLIMATE OUTLOOK INCLUDE: 
1) EL NINO AND LA NINA - WHICH COMPRISE ENSO. IMPACTS OF THESE EVENTS ARE 
SUMMARIZED BY SEPARATING 3-MONTH OBSERVATIONS FROM THREE OR MORE DECADES INTO 
EL NINO, NEUTRAL AND LA NINA SETS, AVERAGING EACH SEPARATELY, AND THEN 
COMPUTING ANOMALIES. THESE ARE CALLED "COMPOSITES" AND USED AT TIMES TO 
SUBJECTIVELY MODIFY THE FORECAST. 
2) TRENDS - APPROXIMATED BY THE OCN TOOL AS THE DIFFERENCE BETWEEN THE MOST 
RECENT 10-YEAR MEAN OF TEMPERATURE OR 15-YEAR MEAN OF PRECIPITATION FOR A GIVEN 
LOCATION AND TIME OF YEAR AND THE 30-YEAR CLIMATOLOGY PERIOD (CURRENTLY 
1981-2010). 
3) THE TROPICAL 30-60 DAY OSCILLATION - CALLED THE MADDEN JULIAN OSCILLATION 
(MJO) - AFFECTS CLIMATE VARIABILITY WITHIN SEASONS. 
4) THE ARCTIC OSCILLATION (AO), THE SIMILAR NORTH ATLANTIC OSCILLATION (NAO), 
AND THE PACIFIC NORTH AMERICAN (PNA) PATTERNS - WHICH AFFECT THE TEMPERATURE 
ANOMALY PATTERN ESPECIALLY DURING BOREAL WINTER AND ARE GENERALLY CONSIDERED TO 
HAVE LOW PREDICTABILITY. 
5) THE PACIFIC DECADAL OSCILLATION (PDO) - AN ENSO-LIKE PATTERN OF CLIMATE 
VARIABILITY AFFECTING THE TROPICS AND THE NORTH PACIFIC AND NORTH AMERICAN 
REGIONS, BUT WHICH VARIES ON A MUCH LONGER TIME-SCALE THAN ENSO. 
6) PERSISTENTLY DRY OR WET SOILS IN THE SPRING AND SUMMER AND SNOW AND ICE 
COVER ANOMALIES IN THE WINTER. THESE FACTORS TEND TO PERSIST FOR LONG PERIODS 
AND ACT AS A KIND OF MEMORY IN THE CLIMATE SYSTEM. 
7) STATISTICAL FORECAST MODELS - CANONICAL CORRELATION ANALYSIS (CCA), 
SCREENING MULTIPLE LINEAR REGRESSION (SMLR), CONSTRUCTED ANALOG (CA), AND 
ENSEMBLE CCA (ECCA). 
8) DYNAMICAL FORECAST MODELS - INCLUDING THE NCEP CLIMATE FORECAST SYSTEM 
VERSION 2 (CFS) AND FOR THE ZERO-LEAD UPDATE FORECASTS THE NCEP GLOBAL ENSEMBLE 
FORECAST SYSTEM (GEFS).  AN EXPERIMENTAL FORECAST SYSTEM, THE NATIONAL 
MULTI-MODEL ENSEMBLE (NMME), COMPRISED OF SEVERAL DYNAMICAL MODELS IS ALSO USED. 
 
 
FORECASTER: ANTHONY ARTUSA 
 
 
THE CLIMATIC NORMALS ARE BASED ON CONDITIONS BETWEEN 1981 AND 2010, FOLLOWING 
THE WORLD METEOROLOGICAL ORGANIZATION CONVENTION OF USING THE MOST RECENT 3 
COMPLETE DECADES AS THE CLIMATE 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. 
 
 
 
AN UPDATED MONTHLY OUTLOOK... FOR AUG WILL BE ISSUED ON THU JULY 31 2014 
 
 
THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1981-2010 BASE PERIOD. 
 
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