PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 300 PM EDT THU MAR 31 2016 30-DAY OUTLOOK DISCUSSION FOR APRIL 2016 THE APRIL MONTHLY UPDATE IS A CHALLENGING FORECAST AS CONSIDERABLE VARIABILITY IS EXPECTED OVER THE NEXT FEW WEEKS FOR MANY AREAS ACROSS THE COUNTRY. SHORT-RANGE, EXTENDED RANGE AND SUBSEASONAL INFORMATION WAS ALL CONSIDERED AND REQUIRED IN ADJUSTING THE APRIL 2016 OUTLOOK FROM MID-MONTH. AT THE START OF THE MONTH, A STRONG RIDGE-TROUGH PATTERN IS FORECAST BY DYNAMICAL MODEL GUIDANCE ACROSS THE CONUS FROM WEST TO EAST AND IS LIKELY TO RESULT IN A PERIOD OF BELOW NORMAL TEMPERATURES FOR AREAS OF THE EASTERN GREAT LAKES AND NORTHEAST FOR THE FIRST WEEK INTO THE START OF THE SECOND WEEK OF APRIL. ALTHOUGH LATER IN WEEK-2 AND EXPERIMENTAL WEEK 3-4 GUIDANCE FAVORS THIS PATTERN TO EASE WITH WARMER TEMPERATURES, THE COLD START TO THE MONTH TILTS THE ODDS SLIGHTLY TOWARD BELOW NORMAL MONTHLY MEAN TEMPERATURES. THE APRIL UPDATED OUTLOOK FAVORS ABOVE NORMAL TEMPERATURES FOR ALASKA AND THE WESTERN CONUS SIMILAR TO THE MID-MONTH OUTLOOK AS SHORT RANGE, EXTENDED RANGE AND WEEK 3-4 EXPERIMENTAL GUIDANCE ALL FAVOR WARMER THAN AVERAGE CONDITIONS IN MOST AREAS, AS DOES THE MONTHLY CFS FORECAST FOR MOST LOCATIONS. PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INCREASED ACROSS MOST OF THE WESTERN CONUS. MOREOVER, ELEVATED ODDS OF ABOVE NORMAL TEMPERATURES ARE EXPANDED, ALBEIT AT MODEST PROBABILITIES, ACROSS THE INTERIOR OF THE CONUS TO THE PLAINS AND EASTWARD TO THE OHIO AND TENNESSEE VALLEYS. FOR PRECIPITATION, SHORT RANGE POTENTIAL HEAVY RAINFALL EARLY IN THE PERIOD TILTS THE ODDS TOWARDS ABOVE MEDIAN FOR MONTHLY PRECIPITATION TOTALS FOR SOME AREAS OF THE SOUTHEAST. THEREAFTER, THE AFOREMENTIONED RIDGE TROUGH PATTERN ACROSS THE CONUS FAVORS ANOMALOUS HIGH PRESSURE ACROSS MUCH OF THE INTERIOR PORTIONS OF THE COUNTRY SOUTHWARD TO THE GULF COAST DURING THE MEDIUM AND EXTENDED RANGE PERIODS. THE BELOW MEDIAN PRECIPITATION AREA HIGHLIGHTED IN THE MID-MONTH OUTLOOK NEAR THE GREAT LAKES IS EXPANDED WESTWARD AND SOUTHWARD AS A RESULT. EXTENDED RANGE GUIDANCE FAVORS ABOVE MEDIAN PRECIPITATION FOR PARTS OF CALIFORNIA, THE SOUTHWEST, THE GREAT BASIN AND THE ROCKIES AS DOES EXPERIMENTAL WEEK 3-4 GUIDANCE FOR AREAS OF THE SOUTHERN AND CENTRAL HIGH PLAINS. MOREOVER, ABOVE MEDIAN PRECIPITATION IS FAVORED IN MONTHLY INTEGRATED CFS MODEL FORECASTS. CONSEQUENTLY, ALTHOUGH CONFIDENCE IS LOW, THE FORECAST FOR ELEVATED ODDS FOR ABOVE MEDIAN PRECIPITATION REMAINS FROM THE MID-MONTH OUTLOOK IN THESE REGIONS. FAVORED BELOW MEDIAN PRECIPITATION FOR THE PACIFIC NORTHWEST AND ABOVE MEDIAN PRECIPITATION FOR AREAS IN ALASKA ARE MAINTAINED IN THE UPDATED OUTLOOK. PREVIOUS DISCUSSION THE APRIL TEMPERATURE AND PRECIPITATION OUTLOOKS WERE PREPARED WITH CONSIDERATIONS FROM ONGOING STRONG EL NINO CONDITIONS, CURRENT MJO ACTIVITY, MOST RECENT SOIL MOISTURE CONDITIONS AS WELL AS AVAILABLE DYNAMICAL MODEL GUIDANCE INTEGRATED OVER MULTIPLE TIME PERIODS. STRONG EL NINO CONDITIONS REMAIN IN PLACE ACROSS THE EQUATORIAL PACIFIC OCEAN WHILE THE MJO CONTINUES TO BE ACTIVE WITH THE ENHANCED CONVECTIVE PHASE NOW CENTERED ACROSS THE EASTERN INDIAN OCEAN AND PROPAGATING EASTWARD WITH TIME. THE MJO IS FORECAST TO REMAIN ACTIVE OVER THE NEXT COUPLE OF WEEKS AND PROPAGATE ACROSS THE MARITIME CONTINENT TO THE WESTERN AND CENTRAL PACIFIC BY APRIL. THE MJO WILL FIRST DESTRUCTIVELY, THEN CONSTRUCTIVELY INTERFERE WITH THE EL NINO BASE STATE OVER THIS PERIOD AND THERE IS LIKELY TO BE CONSIDERABLE VARIABILITY IN THE PATTERN OF ANOMALOUS TROPICAL CONVECTION ACROSS THE MARITIME CONTINENT AND WESTERN PACIFIC DURING THIS PERIOD. BY APRIL, THERE MAY EMERGE A COUPLET OF EQUATORIAL SUPPRESSED/ENHANCED CONVECTION ACROSS THE MARITIME CONTINENT AND WESTERN PACIFIC THAT CAN BE CONSIDERED FOR POTENTIAL TELECONNECTION TO THE HIGHER LATITUDES DURING EARLY APRIL. ABOVE AVERAGE SOIL MOISTURE CONDITIONS ARE EVIDENT IN MID-MARCH FOR A REGION FROM THE SOUTH-CENTRAL CONUS NORTHEASTWARD TO PARTS OF THE MIDWEST AND OHIO VALLEY. THE APRIL TEMPERATURE OUTLOOK FAVORS ABOVE NORMAL TEMPERATURES FOR ALASKA, THE WESTERN CONUS AND PARTS OF THE EASTERN GREAT LAKES, MID-ATLANTIC AND NORTHEAST. AREAS IN ALASKA, THE PACIFIC NORTHWEST AND NORTHERN ROCKIES ARE CONSISTENT WITH EL NINO CONDITIONS AND STRONGLY SUPPORTED BY DYNAMICAL MODEL GUIDANCE AS WELL. ABOVE AVERAGE SEA SURFACE TEMPERATURES (SSTS) IN WATERS NEIGHBORING SOUTHERN ALASKA AND THE WEST COAST ALSO SUPPORT ABOVE NORMAL TEMPERATURES IN THESE AREAS. DYNAMICAL MODEL GUIDANCE SUPPORTS ABOVE NORMAL TEMPERATURES FOR THE CENTRAL AND SOUTHERN ROCKIES AND SOUTHWEST WHICH IS CONSISTENT WITH THE LACK OF EL NINO PRECIPITATION DURING THE WINTER MONTHS IN MANY OF THESE AREAS. LAGGED COMPOSITES WITH CURRENT MJO ACTIVITY SUPPORT POTENTIAL MEAN RIDGING AND ABOVE NORMAL TEMPERATURES ACROSS THE NORTHEAST CORNER OF THE CONUS IN EARLY APRIL AND THIS ALONG WITH SOME DYNAMICAL MODEL GUIDANCE SUPPORT FAVORS A TILT IN THE ODDS FOR ABOVE NORMAL TEMPERATURES IN THIS AREA. WET SURFACE CONDITIONS, POTENTIAL ABOVE MEDIAN PRECIPITATION ON AVERAGE OVER THE PERIOD AND MODEST DYNAMICAL MODEL SUPPORT FAVOR BELOW NORMAL TEMPERATURES FOR PARTS OF THE LOWER MISSISSIPPI VALLEY. THE APRIL PRECIPITATION OUTLOOK FAVORS ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE SOUTHERN HALF OF THE CONUS AND ALSO FOR PARTS OF WESTERN ALASKA. EL NINO CONDITIONS AND DYNAMICAL MODEL GUIDANCE SUPPORT AREAS ACROSS THE WEST, THE PLAINS AND GULF COAST STATES. MJO CONSIDERATIONS ALSO SUPPORT A SLIGHT TILT IN THE ODDS FOR ABOVE MEDIAN PRECIPITATION FOR AREAS IN THE OHIO VALLEY, TENNESSEE VALLEY AND SOUTHEAST EARLY IN THE MONTH. FOR ALASKA, BELOW AVERAGE SEA ICE COVERAGE AND CFS GUIDANCE SUPPORT ABOVE MEDIAN PRECIPITATION IN THE HIGHLIGHTED AREA. BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE ALASKA PANHANDLE, PARTS OF THE PACIFIC NORTHWEST, NORTHERN PLAINS AND WESTERN GREAT LAKES AND IS CONSISTENT WITH EL NINO CONDITIONS AS WELL AS THE MAJORITY OF AVAILABLE DYNAMICAL MODEL GUIDANCE. 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 MAY ... WILL BE ISSUED ON THU APR 21 2016 THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1981-2010 BASE PERIOD. $$