PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK 
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 
300PM EST FRIDAY FEB 28 2014 
 
30-DAY OUTLOOK DISCUSSION FOR MARCH 2014 
 
THE FORECAST RATIONALE FOR THE MARCH MONTHLY TEMPERATURE OUTLOOK REMAINS 
GENERALLY UNCHANGED FROM THE MIDDLE OF LAST WEEK. INFORMATION FROM SHORT-, 
MEDIUM- AND EXTENDED-RANGE MODEL GUIDANCE WAS USED TO ADJUST THE ORIGINAL 
OUTLOOK AND TENDED TO INCREASE COVERAGE AND PROBABILITIES IN MANY AREAS. 
 
THE HIGHLIGHTED REGION OF FAVORED BELOW NORMAL TEMPERATURES OVER THE EASTERN 
CONUS WAS EXPANDED IN ALL DIRECTIONS DUE TO A PERIOD OF MUCH BELOW NORMAL 
TEMPERATURES FAVORED FOR THE FIRST WEEK OF MARCH FOR MUCH OF THE CENTRAL AND 
EASTERN CONUS, A CONTINUATION OF FAVORED BELOW NORMAL TEMPERATURES IN 
EXTENDED-RANGE MODEL GUIDANCE UNTIL AT LEAST MID-MARCH AND A TENDENCY FOR BELOW 
NORMAL TEMPERATURES ACROSS PARTS OF THE CENTRAL AND EASTERN CONUS ASSOCIATED 
WITH STRENGTHENING AND FORECAST MJO ACTIVITY OVER THE NEXT FEW WEEKS. THE CFS 
ALSO DEPICTS QUITE HIGH PROBABILITIES FOR BELOW NORMAL TEMPERATURES FOR MARCH 
FOR THESE AREAS. 
 
AN ENHANCED LIKELIHOOD OF ABOVE-NORMAL TEMPERATURES REMAINS FOR PORTIONS OF THE 
WESTERN CONUS WITH A FEW MINOR ADJUSTMENTS TO COVERAGE AND PROBABILITIES FROM 
THE ORIGINAL MARCH OUTLOOK. THE TEMPERATURE FORECAST FOR ALASKA WAS ADJUSTED TO 
INCLUDE FAVORED ABOVE-NORMAL TEMPERATURES ACROSS THE SOUTHEAST PORTION OF THE 
STATE WHILE REMOVING ENHANCED PROBABILITIES FOR SOME PARTS OF NORTHWEST ALASKA. 
THESE ADJUSTMENTS ARE PRIMARILY BASED ON RECENT RUNS OF THE CFS. 
 
THERE ARE LARGE CHANGES TO THE MARCH PRECIPITATION OUTLOOK. DURING PREPARATION 
FOR THE ORIGINAL MARCH OUTLOOK, SUBSTANTIAL PRECIPITATION CHANCES FOR THE WEST 
COAST AND WESTERN CONUS WERE PRIMARILY FAVORED TO OCCUR EITHER PRIOR TO THE 
BEGINNING OF MARCH AND/OR ACROSS NORTHERN CALIFORNIA AND THE CENTRAL GREAT 
BASIN. SINCE THIS TIME, MODEL GUIDANCE HAS TRENDED SLOWER AND FARTHER SOUTH 
WITH THIS MOISTURE SO THAT PRECIPITATION IS NOW LIKELY TO OCCUR IN VERY EARLY 
MARCH FOR AREAS OF SOUTHERN CALIFORNIA AND THE SOUTHWEST, REGIONS IN WHICH 
CLIMATOLOGICAL PRECIPITATION IS SOMEWHAT LOW THIS TIME OF THE YEAR. 
CONSEQUENTLY, A TWO-CLASS CHANGE IS NECESSARY IN THE OUTLOOK ACROSS SOME AREAS 
IN THE SOUTHWEST. 
 
THE AREA OF FAVORED BELOW-MEDIAN PRECIPITATION HAS BEEN REMOVED AND THE FAVORED 
ABOVE-MEDIAN PRECIPITATION AREA IS SHIFTED CONSIDERABLY SOUTH ACROSS THE 
SOUTHWEST. THIS CHANGE REFLECTS IMPACTS VERY EARLY IN MARCH RATHER THAN ANY 
CONFIDENCE IN A LONGER TERM PATTERN CHANGE OF WHAT HAS BEEN SO FAR A DRY WINTER 
IN THESE AREAS. 
 
EXTENDED RANGE AND LONGER-RANGE CFS MODEL GUIDANCE FAVOR BELOW MEDIAN 
PRECIPITATION ON AVERAGE ACROSS AREAS OF THE NORTHERN PLAINS AND GREAT LAKES 
SITUATED UPSTREAM OF THE MEAN EASTERN NORTH AMERICA TROUGH. 
 
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PREVIOUS DISCUSSION FROM 2/20 IS BELOW. 
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ALTHOUGH ENSO-NEUTRAL CONDITIONS REMAIN IN PLACE, THERE CONTINUES TO PERSIST A 
LOW FREQUENCY SIGNAL FAVORING ENHANCED TROPICAL CONVECTION ACROSS THE EASTERN 
MARITIME CONTINENT AND WESTERN PACIFIC REGION. THIS AREA OF ENHANCED TROPICAL 
RAINFALL HAS PERSISTED SINCE LATE NOVEMBER AND HAS SLOWLY SHIFTED EASTWARD WITH 
TIME. SUBSEASONAL VARIABILITY HAS ON OCCASION SUPPRESSED CONVECTION IN THIS 
REGION, SUCH AS IN EARLY FEBRUARY. IN THE COMING 1-2 WEEKS, SUBSEASONAL 
VARIABILITY IS LIKELY TO REINFORCE THE AFOREMENTIONED LOW FREQUENCY ANOMALOUS 
CONVECTION AND THIS SCENARIO IS INDICATED BY CFS DYNAMICAL MODEL FORECASTS. 
 
THIS ORIENTATION OF TROPICAL CONVECTION IS GENERALLY CONSISTENT WITH THE CFS 
FORECAST CIRCULATION DURING LATE FEBRUARY INTO MARCH WHICH FAVORS, IN THE MEAN, 
UPPER-LEVEL TROUGHING ACROSS THE NORTH PACIFIC, RIDGING NEAR THE WEST COAST OF 
NORTH AMERICA AND TROUGHING ACROSS EASTERN NORTH AMERICA. THE MARCH TEMPERATURE 
OUTLOOK INDICATES AN AREA OF FAVORED BELOW NORMAL MONTHLY MEAN TEMPERATURES FOR 
PORTIONS OF THE NORTHERN PLAINS, GREAT LAKES, OHIO VALLEY AND NORTHEAST. 
DYNAMICAL MODEL GUIDANCE AND MORE TRADITIONAL STATISTICAL FORECAST TOOLS FAVOR 
ABOVE NORMAL TEMPERATURES FOR MUCH OF THE SOUTHWEST QUARTER OF THE CONUS. 
ANTICIPATED RIDGING ACROSS PORTIONS OF WESTERN NORTH AMERICA INTO ALASKA 
SUPPORTS STRONG MEAN SOUTHERLY FLOW INTO ALASKA, ESPECIALLY EARLY IN THE MONTH 
SO ABOVE NORMAL TEMPERATURES ARE FAVORED FOR WESTERN AREAS OF ALASKA. BELOW 
AVERAGE SEA ICE EXTENT AND ABOVE AVERAGE SEA SURFACE TEMPERATURES IN THE BERING 
SEA ALSO SUPPORT THIS FORECAST. 
 
IN AREAS WHERE CLIMATE SIGNALS ARE WEAK AND/OR NOT RELIABLE, EQUAL CHANCES (EC) 
OF BELOW-, NEAR- AND ABOVE-NORMAL MEAN MONTHLY TEMPERATURES ARE INDICATED. 
 
THE CONFIDENCE IN THE PRECIPITATION OUTLOOK IS LESS THAN THAT FOR TEMPERATURE, 
WHICH IS OFTEN THE CASE. DYNAMICAL MODEL GUIDANCE CONSISTENT WITH THE ABOVE 
DESCRIBED FORECAST CIRCULATION ACROSS THE PACIFIC NORTH AMERICA REGION IS THE 
PRIMARY FORECAST DRIVER FOR THE MARCH PRECIPITATION OUTLOOK. THE CFS, AS WELL 
AS THE CCA STATISTICAL TOOL, FAVOR BELOW-MEDIAN PRECIPITATION UNDER RIDGING 
ACROSS SOUTHERN CALIFORNIA, MUCH OF ARIZONA AND WESTERN NEW MEXICO. EXTENDED 
RANGE MODEL GUIDANCE HIGHLIGHTS THE POTENTIAL FOR THE WESTERN NORTH AMERICA 
RIDGE FORECAST IN LATE FEBRUARY TO CUTOFF TOWARDS ALASKA ALLOWING THE PACIFIC 
JET TO UNDERCUT THE RIDGE IN EARLY MARCH AND LEAD TO INCREASED MOISTURE INTO 
MUCH OF CALIFORNIA, THE PACIFIC NORTHWEST, THE INTERMOUNTAIN WEST AND NORTHERN 
ROCKIES. CONSEQUENTLY, ELEVATED ODDS OF ABOVE-MEDIAN PRECIPITATION IS INDICATED 
IN THESE AREAS, ALSO CONSISTENT WITH MANY RECENT RUNS OF THE CFS. 
 
ALTHOUGH A POTENTIAL MEAN LONGWAVE TROUGH CENTERED ACROSS EASTERN NORTH AMERICA 
WOULD GENERALLY FAVOR DRIER THAN AVERAGE CONDITIONS IN THE MIDWEST, THERE IS 
SIMPLY TOO MUCH UNCERTAINTY IN THE EXTENT IN WHICH SHORTWAVE TROUGHS MAY 
EMANATE FROM THE WESTERN U.S. INTO AREAS WHERE CLIMATOLOGIES ARE GENERALLY LOW, 
AT LEAST DURING THE FIRST HALF OF THE MONTH. MOREOVER, THERE HAS BEEN 
CONSIDERABLE VARIABILITY IN CFS FORECASTS FOR BOTH THE CENTRAL PORTION OF THE 
COUNTRY AS WELL AS ALONG THE GULF COAST (POTENTIAL WET SIGNAL) FOR HIGHLIGHTED 
AREAS AT THIS TIME. THESE AREAS WILL BE REVISITED WHEN DOING THE MONTHLY 
UPDATE. 
 
IN AREAS WHERE CLIMATE SIGNALS ARE WEAK AND/OR NOT RELIABLE, EQUAL CHANCES (EC) 
OF BELOW-, NEAR- AND ABOVE-MEDIAN TOTAL MONTHLY PRECIPITATION ARE 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: 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. 
 
 
 
THE NEXT MONTHLY OUTLOOK...FOR APR ... WILL BE ISSUED ON THU MAR 20 2014 
 
 
THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1981-2010 BASE PERIOD. 
 
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