30 Day Narrative

409 
FXUS07 KWBC 161331
PMD30D
PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830 AM EST THU FEB 16 2017
30-DAY OUTLOOK DISCUSSION FOR MARCH 2017
AN INITIAL REVIEW OF SOME OF THE FACTORS TYPICALLY CONSIDERED IN FORMULATING 
THE HALF MONTH LEAD MONTHLY OUTLOOK INCLUDE CONDITIONS ACROSS THE TROPICS. 
OCEANIC AND MOST ATMOSPHERIC INDICATORS ASSOCIATED WITH LA NINA CONDITIONS HAVE 
FADED AND CPC ISSUED ITS FINAL LA NINA ADVISORY EARLIER THIS MONTH. LA NINA WAS 
NOT CONSIDERED IN THE MARCH 2017 TEMPERATURE AND PRECIPITATION OUTLOOK. AT THE 
SUBSEASONAL TIME SCALE, WE DO HOWEVER, OBSERVE A ROBUST MJO EVENT WITH THE 
ENHANCED CONVECTIVE PHASE CENTERED ACROSS THE WESTERN HEMISPHERE AND THE 
SUPPRESSED CONVECTIVE PHASE LOCATED ACROSS THE INDIAN OCEAN AND MARITIME 
CONTINENT REGION AND THIS SIGNAL WAS CONSIDERED IN DEVELOPING THE MARCH 
OUTLOOK. ANOMALOUS SNOW COVER AND ABOVE NORMAL COASTAL SEA SURFACE TEMPERATURES 
IN SOME AREAS WERE ALSO CONSIDERED.
INFORMATION FROM DYNAMICAL MODEL GUIDANCE PLAYED A LARGE ROLE AS WELL IN THE 
INITIAL MARCH 2017 OUTLOOK AND INCLUDED WEEK 3-4 MODEL GUIDANCE FROM THE CFS 
AND ECMWF MODEL SYSTEMS AND MONTHLY GUIDANCE AS A WHOLE FROM THE CFS. 
STATISTICAL FORECAST GUIDANCE LINKED TO PREDICTORS SUCH AS THE MJO, ENSO AND 
TREND FOR THE WEEK 3-4 TIME PERIOD ALSO CONTRIBUTED TO THE OUTLOOK.
THE MARCH 2017 TEMPERATURE OUTLOOK DEPICTS A CONSIDERABLE AREA OF EQUAL CHANCES 
(EC) AT THIS HALF MONTH LEAD AS THERE IS CONSIDERABLE UNCERTAINTY IN A NUMBER 
OF THE FORECAST TOOLS. LAGGED 200-HPA HEIGHT AND TEMPERATURE COMPOSITES LINKED 
TO THE CURRENT MJO PHASE WOULD TEND TO FAVOR IN TIME NEGATIVE HEIGHT DEPARTURES 
AND AREAS OF BELOW NORMAL TEMPERATURES FOR CONSIDERABLE PORTIONS OF THE CONUS 
DURING LATER FEBRUARY INTO EARLY MARCH INCLUDING THE EASTERN U.S. THIS IS 
CURRENTLY AT ODDS WITH WEEK-2 GUIDANCE WHICH ON AVERAGE CONTINUES TO FAVOR 
ABOVE-NORMAL TEMPERATURES IN THIS REGION CLOSE TO EARLY MARCH.   
FOR THE INITIAL MARCH 2017 OUTLOOK, BELOW NORMAL TEMPERATURES ARE FAVORED FOR A 
REGION WHERE MJO RELATED INFORMATION (ABOVE DESCRIBED COMPOSITES AND 
STATISTICAL FORECAST TOOLS) AND DYNAMICAL MODEL GUIDANCE FROM BOTH WEEK 3-4 AND 
THE CFS MONTHLY FORECAST ARE CONSISTENT. THIS REGION IS FOR A SMALL AREA THAT 
INCLUDES PORTIONS OF THE NORTHERN ROCKIES AND NORTHERN HIGH PLAINS. ABOVE 
NORMAL TEMPERATURES ARE FAVORED ACROSS THE SOUTHERN TIER OF THE CONTIGUOUS U.S. 
WHERE, IN GENERAL, THERE IS AGREEMENT FROM WEEK 3-4 MODEL GUIDANCE FROM THE CFS 
AND ECMWF AND THE CFS MONTHLY FORECAST AS WELL AS SUPPORT FROM LONG TERM 
TRENDS.          ABOVE NORMAL TEMPERATURES ARE FAVORED FOR PORTIONS OF WESTERN 
ALASKA SUPPORTED BY ABOVE NORMAL SEA SURFACE TEMPERATURES IN SOME AREAS AND 
AVAILABLE DYNAMICAL MODEL GUIDANCE. 
THE MARCH 2017 PRECIPITATION OUTLOOK IS STRONGLY BASED ON AVAILABLE DYNAMICAL 
MODEL GUIDANCE AND TO A LESSER DEGREE MJO CONSIDERATIONS. ABOVE MEDIAN 
PRECIPITATION IS FAVORED FOR PORTIONS OF THE SOUTHEAST CONUS IN PART DUE TO MJO 
STATISTICAL FORECAST GUIDANCE AND IS ALSO SUPPORTED BY DYNAMICAL MODEL GUIDANCE 
FROM BOTH THE WEEK 3-4 PERIOD GUIDANCE AS WELL AS THE CFS MONTHLY FORECAST. 
ABOVE MEDIAN PRECIPITATION IS ALSO MOST LIKELY DURING MARCH 2017 FOR AREAS OF 
THE NORTHERN ROCKIES AND NORTHERN HIGH PLAINS WHERE BOTH LONG TERM TRENDS AND 
DYNAMICAL MODEL GUIDANCE DEPICT A POTENTIAL SIGNAL. PRIMARILY BASED ON THE CFS 
MONTHLY FORECAST AND LONG TERM TRENDS, THERE ARE ELEVATED ODDS FOR BELOW-MEDIAN 
PRECIPITATION FOR AREAS STRETCHING FROM ARIZONA TO WEST TEXAS, WHILE 
WEST-CENTRAL ALASKA IS FAVORED TO SEE ABOVE-MEDIAN PRECIPITATION.
FORECASTER: JON GOTTSCHALCK
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 MAR WILL BE ISSUED ON TUE FEBRUARY 28 2017
THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1981-2010 BASE PERIOD.
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