30 Day Narrative

181 
FXUS07 KWBC 211230
PMD30D
PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830 AM EDT THU JUL 21 2016
30-DAY OUTLOOK DISCUSSION FOR AUGUST 2016
THE AUGUST 2016 TEMPERATURE AND PRECIPITATION OUTLOOKS ARE BASED ON DYNAMICAL 
MODEL GUIDANCE AND STATISTICAL TOOLS, WITH SOME CONSIDERATION OF CURRENT SOIL 
MOISTURE CONDITIONS. ENSO IS NOW IN ITS NEUTRAL PHASE ACROSS THE TROPICAL 
PACIFIC. LA NINA IS FAVORED TO DEVELOP DURING THE AUGUST-OCTOBER SEASON, WITH 
ABOUT A 55-60 PERCENT CHANCE OF LA NINA DURING THE UPCOMING AUTUMN AND WINTER. 
PLEASE REFER TO THE ENSO DIAGNOSTIC DISCUSSION AT: 
HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/ANALYSIS_MONITORING/ENSO_ADVISORY/ FOR A 
MORE DETAILED ANALYSIS OF ENSO CONDITIONS ACROSS THE EQUATORIAL PACIFIC. DURING 
THE PAST WEEK, THE WHEELER-HENDON RMM INDEX INDICATED SOME STRENGTHENING OF THE 
MADDEN-JULIAN OSCILLATION (MJO) SIGNAL OVER AFRICA. DURING THE NEXT TWO WEEKS, 
THE GFS ENSEMBLE INDICATES EASTWARD PROPAGATION AND GRADUAL WEAKENING OF THE 
MJO SIGNAL OVER THE INDIAN OCEAN. NEITHER THE CURRENT NEUTRAL PHASE OF ENSO NOR 
THE MJO SIGNAL ARE EXPECTED TO PROVIDE MUCH GUIDANCE IN THE FORMULATION OF THE 
MONTHLY TEMPERATURE AND PRECIPITATION OUTLOOKS FOR AUGUST 2016. THEREFORE, THE 
OUTLOOKS RELY PRIMARILY UPON THE LATEST DYNAMICAL MODEL GUIDANCE FROM THE NCEP 
CLIMATE FORECAST SYSTEM (CFS), THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME), 
THE INTERNATIONAL MULTI-MODEL ENSEMBLE (IMME), AND MODEL GUIDANCE FOR WEEKS 3 
AND 4 FROM THE CFS, JAPAN METEOROLOGICAL AGENCY (JMA), AND ECMWF, AS WELL AS 
CLIMATE RELATIONSHIPS TO CURRENT SOIL MOISTURE CONDITIONS.
DYNAMICAL MODELS INDICATE INCREASED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES 
ACROSS MUCH OF THE CONTIGUOUS U.S. AND ALASKA, WITH THE EXCEPTION OF PARTS OF 
THE NORTHERN AND CENTRAL PLAINS, UPPER MISSISSIPPI VALLEY, MOST OF THE GREAT 
LAKES REGION, AND PORTIONS OF THE SOUTHERN PLAINS, WHERE A NUMBER OF MODELS 
PREDICT EITHER THE LOWER OR MIDDLE TERCILE FOR TEMPERATURE. CURRENT SOIL 
MOISTURE CONDITIONS IN THESE AREAS GENERALLY RANK ABOVE THE 80TH PERCENTILE, 
AND CPC'S EXPERIMENTAL WEEK 3 AND 4 FORECASTS FAVOR EQUAL CHANCES (EC) OF BELOW 
AND ABOVE-NORMAL TEMPERATURES FOR MUCH OF THIS REGION, AND REDUCED 
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ACROSS THE SOUTHERN PLAINS. BASED 
ON SOME OF THE DYNAMICAL MODELS, CURRENT SOIL MOISTURE CONDITIONS, AND THE 
EXPERIMENTAL WEEK 3 AND 4 FORECASTS, EC IS CONSIDERED THE MOST LIKELY OPTION. 
HOWEVER, AS NOTED EARLIER, MUCH OF THE CONTIGUOUS U.S. AND ALASKA ARE FORECAST 
TO EXPERIENCE ABOVE-NORMAL TEMPERATURES DURING AUGUST. THIS IS CONSISTENT WITH 
MOST DYNAMICAL MODEL PREDICTIONS AND STATISTICAL TOOLS, WHICH INCORPORATE THE 
DECADAL CLIMATE WARMING TRENDS, AS WELL AS THE POTENTIAL INFLUENCE OF SEA 
SURFACE TEMPERATURE (SST) PATTERNS. IN ALASKA, PROBABILITIES FOR ABOVE-NORMAL 
TEMPERATURES ARE GREATEST IN THE FAR SOUTH, DUE IN PART TO SSTS IN EXCESS OF 
1.5-2.0 DEGREES C.
CALIBRATED PROBABILITIES FROM THE CONSENSUS OF THE NMME DYNAMICAL MODELS, AND 
THE CFS, GFDL, NASA, AND CMC (CANADIAN) MODELS INDICATE AN INCREASED CHANCE OF 
ABOVE-MEDIAN PRECIPITATION FOR PORTIONS OF THE NORTHERN AND CENTRAL PLAINS, AND 
THE UPPER AND MIDDLE MISSISSIPPI VALLEY. THESE SAME TOOLS, IN ADDITION TO CPC'S 
WEEK 3 AND 4 FORECASTS, LEND SUPPORT FOR ENHANCED PROBABILITIES OF ABOVE-MEDIAN 
PRECIPITATION FOR PORTIONS OF THE DESERT SOUTHWEST. A CONSENSUS OF DYNAMICAL 
MODEL FORECASTS INDICATES AN INCREASED CHANCE OF ABOVE-MEDIAN PRECIPITATION FOR 
SOUTHEASTERN ALASKA AND THE PANHANDLE REGION. BELOW-MEDIAN PRECIPITATION IS 
FAVORED ACROSS THE INTERIOR NORTHWEST, THE CENTRAL GULF COAST REGION, AND MUCH 
OF THE GREAT LAKES REGION, AND IS SUPPORTED PRIMARILY BY THE IMME AND THE 
LATEST RUNS OF THE CFS. ADDITIONAL MODEL SUPPORT COMES FROM THE CMC, GFDL, AND 
CPC'S WEEK 3 AND 4 FORECASTS.
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 SUN JULY 31 2016
THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1981-2010 BASE PERIOD.
$$