148  
FXUS07 KWBC 312001  
PMD30D  
PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
300 PM EST TUE JAN 31 2023  
 
30-DAY OUTLOOK DISCUSSION FOR FEBRUARY 2023  
 
THE CURRENT STATE OF THE EL NIñO SOUTHERN OSCILLATION (ENSO) REMAINS IN THE  
NEGATIVE PHASE WITH THE LATEST WEEKLY OBSERVED NIñO 3.4 INDEX VALUE STANDING AT  
-0.6 DEGREES CELSIUS. MEANWHILE, THE AMPLITUDE OF THE MADDEN JULIAN OSCILLATION  
(MJO) HAS INCREASED DURING LATE JANUARY OVER THE EAST-CENTRAL INDIAN OCEAN AND  
IS FORECAST TO PROPAGATE EASTWARD TO THE MARITIME CONTINENT AND WEST PACIFIC  
THROUGH MID-FEBRUARY. THE ARCTIC OSCILLATION (AO) AND NORTH ATLANTIC  
OSCILLATION (NAO) HAVE BOTH BEEN IN THE POSITIVE PHASE IN RECENT DAYS WHILE THE  
PACIFIC NORTH AMERICAN (PNA) PATTERN HAS TRANSITIONED TO THE NEGATIVE PHASE.  
COMPOSITES DERIVED FROM THE RECENT EVOLUTION OF ENSO AND EXTRA-TROPICAL INDICES  
DEPICT ANOMALOUS RIDGING OFF THE WEST COAST OF NORTH AMERICA AS WELL AS OVER  
THE SOUTHEASTERN CONTIGUOUS UNITED STATES (CONUS). ANOMALOUS TROUGHING IS  
INDICATED ACROSS THE NORTHERN PLAINS TO MUCH OF THE INTERIOR WEST. HOWEVER, MJO  
COMPOSITES SHOW ANOMALOUS RIDGING OVER THE EASTERN CONUS STRETCHING WESTWARD  
ACROSS MUCH OF THE PLAINS. ADDITIONALLY, MJO COMPOSITES DEPICT INCREASED  
TROUGHING OVER ALASKA RELATIVE TO COMPOSITES DERIVED FROM ENSO. THE COMPETING  
INFLUENCES FROM ENSO AND THE MJO INTRODUCES INCREASED UNCERTAINTY ACROSS LARGE  
PORTIONS OF THE FORECAST DOMAIN. THE CURRENT ROBUST MJO EVENT IS EXPECTED TO BE  
A SIGNIFICANT DRIVER FOR THE EVOLUTION OF THE OVERALL PATTERN DURING THE MONTH  
OF FEBRUARY AND IS A MAJOR FACTOR IN CONTRIBUTING TO MODIFICATIONS IN THE  
CURRENT UPDATED OUTLOOKS AS COMPARED TO THE FEBRUARY OUTLOOKS ISSUED ON JANUARY  
19 (HEREIN REFERRED TO AS THE MID-MONTH OUTLOOKS). IN ADDITION TO ANALYSIS OF  
THE CURRENT EVOLUTION OF ENSO, THE MJO, AND EXTRATROPICAL INDICES SUCH AS THE  
AO, NAO, AND PNA, SHORT TERM DYNAMICAL MODEL GUIDANCE IS RELIED UPON WITH THE  
OFFICIAL SHORT AND MEDIUM RANGE OUTLOOKS FROM THE WEATHER PREDICTION CENTER  
(WPC), 6-10 DAY AND 8-14 DAY OUTLOOKS FROM THE CLIMATE PREDICTION CENTER (CPC),  
AND WEEKS 3-4 OUTLOOKS FROM CPC CONTRIBUTING SIGNIFICANTLY TO THE UPDATED  
FEBRUARY 2023 OUTLOOKS. DYNAMICAL MODEL GUIDANCE FROM THE CLIMATE FORECAST  
SYSTEM VERSION 2 (CFSV2), THE GLOBAL FORECAST SYSTEM (GFS), THE EUROPEAN CENTRE  
FOR MEDIUM RANGE WEATHER FORECASTS (ECMWF), AND ENVIRONMENT AND CLIMATE CHANGE  
CANADA (ECCC) WERE UTILIZED TO SUPPLEMENT THE OFFICIAL OUTLOOKS. ANTECEDENT  
CONDITIONS SUCH AS EXTRATROPICAL SEA SURFACE TEMPERATURES (SSTS), SEA ICE  
EXTENT, AND SNOW COVER ANOMALIES ALSO WERE FACTORS IN THE CONSTRUCTION OF THE  
FEBRUARY OUTLOOKS WHERE APPROPRIATE.  
 
SHORT AND MEDIUM RANGE OUTLOOKS FROM WPC AND CPC AS WELL AS ENSO-BASED  
STATISTICAL GUIDANCE ARE IN GOOD AGREEMENT IN FAVORING ABOVE NORMAL  
TEMPERATURES ACROSS MUCH OF THE EASTERN CONUS. MJO COMPOSITES ALSO SUPPORT AN  
EXPANSION OF MILDER THAN NORMAL CONDITIONS WESTWARD ACROSS MOST OF THE PLAINS.  
THEREFORE, THE AREAL EXTENT OF ENHANCED ABOVE NORMAL TEMPERATURE PROBABILITIES  
IS INCREASED RELATIVE TO THE MID-MONTH OUTLOOK AND NOW COVERS MOST OF THE  
EASTERN THIRD OF THE CONUS. ONE EXCEPTION IS FOR NORTHERN NEW ENGLAND, WHERE EC  
IS INDICATED DUE TO THE POTENTIAL FOR A BRIEF COLD SNAP EARLY IN THE MONTH. DUE  
TO THE WARM SIGNAL SHOWN BY MJO-BASED COMPOSITES OVER THE CENTRAL CONUS,  
ENHANCED BELOW NORMAL TEMPERATURES DEPICTED IN THE MID-MONTH OUTLOOK OVER THE  
NORTHERN PLAINS HAS BEEN REMOVED AND EQUAL CHANCES (EC) IS NOW DEPICTED ACROSS  
THIS REGION. CONVERSELY, DYNAMICAL MODEL GUIDANCE FROM THE CFSV2 IS MUCH COLDER  
ACROSS THE SOUTHWESTERN CONUS RELATIVE TO GUIDANCE AVAILABLE IN MID-JANUARY.  
THIS TREND IN THE CFSV2 AS WELL AS SUPPORT FROM CPC’S 6-10 DAY, WEEK-2, AND  
WEEKS 3-4 OUTLOOKS LED TO AN EXPANSION OF ENHANCED BELOW NORMAL TEMPERATURE  
PROBABILITIES ACROSS THE CONUS FROM THE ROCKIES WESTWARD. ANOMALOUS SNOW COVER  
IS ALSO A CONTRIBUTING FACTOR IN INCREASING CHANCES OF BELOW NORMAL  
TEMPERATURES ACROSS PARTS OF THE WEST. UNCERTAINTY IS VERY HIGH FOR THE  
TEMPERATURE OUTLOOK ACROSS THE STATE OF ALASKA. COMPOSITES DERIVED FROM MJO AND  
ENSO YIELD CONFLICTING SIGNALS WITH THE FORMER PRODUCING A MUCH COLDER SIGNAL  
ACROSS WESTERN PARTS OF THE STATE. CONFLICTING SIGNALS ARE ALSO EVIDENT ACROSS  
TIME SCALES AS THE CPC 6-10 DAY AND WEEK-2 OUTLOOKS TILT COLD ACROSS NORTHERN  
AND WESTERN ALASKA WHILE THE CPC WEEKS 3-4 OUTLOOKS DEPICT THE OPPOSITE. DUE TO  
THESE UNCERTAINTIES, EC IS INDICATED ACROSS MUCH OF ALASKA. THE LONE EXCEPTION  
IS ACROSS THE ALEUTIANS AND ALASKA PENINSULA, WHERE A SLIGHT TILT TOWARD ABOVE  
NORMAL TEMPERATURES IS INDICATED BASED PRIMARILY ON CURRENT OBSERVATIONS OF  
ABOVE NORMAL SSTS AND BELOW NORMAL SEA ICE EXTENT.  
 
AN ACTIVE PATTERN IS LIKELY ACROSS MUCH OF THE EASTERN CONUS AS SHORT AND  
MEDIUM RANGE GUIDANCE FROM WPC AND CPC GENERALLY SUPPORT ABOVE NORMAL  
PRECIPITATION ACROSS MUCH OF THE REGION. GUIDANCE FROM THE CFSV2 HAS TRENDED  
SOUTH IN BRINGING INCREASED CHANCES OF ABOVE NORMAL PRECIPITATION CHANCES  
ACROSS MUCH OF THE SOUTHEAST AND LOWER MISSISSIPPI VALLEY, AND SOUTHERN PLAINS,  
IN-LINE WITH CURRENT WPC AND CPC SHORT AND MEDIUM RANGE OUTLOOKS. THEREFORE,  
THE AREA OF ENHANCED ABOVE NORMAL PRECIPITATION CHANCES HAS EXPANDED ACROSS THE  
EASTERN AND CENTRAL CONUS RELATIVE TO THE MID-MONTH OUTLOOK AND NOW EXTENDS  
SOUTHWARD TO THE SOUTHEAST, GULF COAST, LOWER MISSISSIPPI VALLEY, AND SOUTHERN  
PLAINS. CORRESPONDINGLY, AREAS OF ENHANCED BELOW NORMAL PRECIPITATION  
PROBABILITIES ARE SUPPRESSED TO THE FLORIDA PENINSULA AND SOUTHERN TEXAS.  
INCREASED UNCERTAINTY IS EVIDENT FARTHER TO THE WEST, ALONG THE WEST COAST OF  
THE CONUS. THE CFSV2 HAS TRENDED DRIER ALONG THE WEST COAST RELATIVE TO  
MID-MONTH AND ENSO AND MJO-BASED COMPOSITES YIELD CONFLICTING SIGNALS. THESE  
FACTORS, COMBINED WITH RELATIVELY WEAK PROBABILITIES DEPICTED IN CPC’S 6-10  
DAY, WEEK-2, AND WEEKS 3-4 OUTLOOKS RESULTED IN A FORECAST OF EC ALONG THE WEST  
COAST OF THE CONUS. ABOVE NORMAL PRECIPITATION IS STILL FAVORED FOR THE  
NORTHERN ROCKIES, WHERE CPC OUTLOOKS AT VARIOUS TIME SCALES WITHIN THE MONTH OF  
FEBRUARY ARE IN GENERAL AGREEMENT. CONVERSELY, A TILT TOWARD BELOW NORMAL  
PRECIPITATION IS INDICATED FOR PARTS OF THE SOUTHWEST, CONSISTENT WITH THE CPC  
WEEKS 3-4 OUTLOOKS AND WITH RECENT FEBRUARY TRENDS. A TILT TOWARD ABOVE NORMAL  
PRECIPITATION IS INDICATED FOR MUCH OF WESTERN AND SOUTHERN ALASKA, CONSISTENT  
WITH ENSO COMPOSITES, CPC OFFICIAL WEEK-2 AND WEEKS 3-4 OUTLOOKS, AND THE  
LATEST CFSV2 GUIDANCE.  
 
*******************************************************************************  
 
****** PREVIOUS MID-MONTH DISCUSSION BELOW ******  
 
*******************************************************************************  
 
THE FEBRUARY 2023 OUTLOOKS ARE ISSUED AGAINST THE BACKDROP OF AN ONGOING LA  
NIñA EVENT AND A WEAKENING MADDEN JULIAN OSCILLATION (MJO) SIGNAL. THE LATEST  
NIñO 3.4 WEEKLY SEA SURFACE TEMPERATURE (SST) DEPARTURES STOOD AT -0.7 DEGREES  
CELSIUS. DURING THE LAST TWO MONTHS, NEGATIVE SUBSURFACE TEMPERATURE ANOMALIES  
WEAKENED, BUT WEAK ANOMALIES CONTINUE TO RESIDE NEAR THE SURFACE OF THE CENTRAL  
AND EASTERN PACIFIC OCEAN. MEANWHILE, THE MAGNITUDE OF THE REAL-TIME  
MULTIVARIATE (RMM) BASED MJO INDEX HAS WEAKENED AND HAS BECOME QUASI-STATIONARY  
OVER THE WESTERN HEMISPHERE DURING THE PAST WEEK. HOWEVER, THERE IS GENERAL  
AGREEMENT ON THE DEVELOPMENT OF A WELL ORGANIZED AND POTENTIALLY ROBUST INDIAN  
OCEAN MJO EVENT DURING THE NEXT TWO WEEKS. FARTHER TO THE NORTH, ACROSS THE  
EXTRATROPICS OF THE NORTHERN HEMISPHERE, THE ARCTIC OSCILLATION (AO) HAS BEEN  
PREDOMINANTLY NEGATIVE DURING EARLY JANUARY WHILE THE NORTH ATLANTIC  
OSCILLATION (NAO) HAS GENERALLY BEEN POSITIVE. MEANWHILE, THE PACIFIC NORTH  
AMERICA (PNA) INDEX HAS EXHIBITED A WEAKENING POSITIVE SIGNAL AND HAS SWITCHED  
TO THE NEGATIVE PHASE DURING THE PAST FEW DAYS. COMBINED NATURAL ANALOG  
COMPOSITES DERIVED FROM THE RECENT EVOLUTION OF EQUATORIAL PACIFIC, MJO, AND  
EXTRATROPICAL INDICES DEPICT A 500-HPA FLOW PATTERN FOR THE MONTH OF FEBRUARY  
DOMINATED BY BELOW NORMAL HEIGHTS ACROSS THE NORTHERN PLAINS. ANOMALOUS RIDGING  
IS GENERALLY FAVORED OVER THE EASTERN NORTH PACIFIC AND ACROSS THE SOUTHEASTERN  
CONTIGUOUS UNITED STATES (CONUS). TRENDS DURING THE LAST 15 YEARS FAVOR ABOVE  
NORMAL HEIGHTS ACROSS MOST OF ALASKA AND THE SOUTHEASTERN CONUS AND BELOW  
NORMAL HEIGHTS OVER THE NORTHERN PLAINS DURING THE MONTH OF FEBRUARY. NATURAL  
ANALOG COMPOSITES, TRENDS, DYNAMICAL GUIDANCE FROM THE COPERNICUS CLIMATE  
CHANGE SERVICE (C3S), NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME), AND THE  
COUPLED FORECAST SYSTEM VERSION 2 (CFSV2), AS WELL AS INPUT FROM THE CLIMATE  
PREDICTION CENTER (CPC) WEEKS 3 AND 4 OUTLOOKS FORM THE BASIS OF THE FEBRUARY  
OUTLOOKS. ANTECEDENT CONDITIONS SUCH AS EXTRATROPICAL SSTS, SEA ICE EXTENT, AND  
SNOW COVER ANOMALIES WERE ALSO CONSIDERED WHERE APPROPRIATE.  
 
BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE ALASKA PANHANDLE, THE PACIFIC  
NORTHWEST, AND NORTHERN CALIFORNIA EASTWARD TO THE NORTHERN PLAINS, CONSISTENT  
WITH DYNAMICAL MODEL GUIDANCE FROM THE CFSV2 AND WITH ANOMALOUS TROUGHING  
DEPICTED BY NATURAL ANALOG COMPOSITES AND TRENDS ACROSS THE NORTH-CENTRAL  
CONUS. CONVERSELY, DYNAMICAL MODEL GUIDANCE SUPPORTS ENHANCED ABOVE NORMAL  
TEMPERATURE PROBABILITIES ACROSS THE SOUTHEAST, EXTENDING NORTHWARD TO SOUTHERN  
NEW ENGLAND AND WESTWARD TO PARTS OF THE SOUTHERN PLAINS. THE HIGHEST  
PROBABILITIES OF ABOVE NORMAL TEMPERATURES (GREATER THAN 50 PERCENT CHANCES)  
ARE INDICATED FOR THE FLORIDA PENINSULA NORTHWARD TO COASTAL AREAS OF SOUTH  
CAROLINA, ASSOCIATED WITH ANTICIPATED ANOMALOUS RIDGING. ABOVE NORMAL  
TEMPERATURES ARE ALSO FAVORED FOR NORTHERN AND WESTERN ALASKA, CONSISTENT WITH  
DYNAMICAL MODEL GUIDANCE AND WITH CURRENT BELOW NORMAL SEA ICE EXTENT, ABOVE  
NORMAL SEA SURFACE TEMPERATURES IN ICE-FREE REGIONS, AND RECENT TRENDS. EQUAL  
CHANCES (EC) OF ABOVE, NEAR, AND BELOW NORMAL TEMPERATURES ARE INDICATED ACROSS  
THE SOUTHWESTERN CONUS, CENTRAL PLAINS, MUCH OF THE GREAT LAKES, PARTS OF THE  
NORTHEAST, AND MUCH OF MAINLAND ALASKA DUE TO WEAK OR CONFLICTING DYNAMICAL AND  
STATISTICAL GUIDANCE.  
 
DYNAMICAL AND STATISTICAL GUIDANCE ARE IN GOOD AGREEMENT IN DEPICTING INCREASED  
CHANCES OF ABOVE NORMAL PRECIPITATION ACROSS THE OHIO VALLEY, GREAT LAKES, AND  
MUCH OF THE MIDDLE AND UPPER MISSISSIPPI VALLEY, ASSOCIATED WITH AN ANTICIPATED  
ENHANCED BAROCLINIC ZONE. BELOW NORMAL PRECIPITATION IS FAVORED FARTHER TO THE  
SOUTH, ACROSS MUCH OF THE SOUTHEAST, CONSISTENT WITH PREDICTED MEAN ANOMALOUS  
RIDGING. INCREASED CHANCES OF BELOW NORMAL PRECIPITATION EXTEND WESTWARD ALONG  
MUCH OF THE SOUTHERN TIER OF THE CONUS DUE TO GOOD AGREEMENT AMONG NMME, CFSV2,  
AND C3S GUIDANCE. CONVERSELY, A TILT TOWARD ABOVE NORMAL PRECIPITATION IS  
INDICATED ALONG MOST OF THE NORTHERN TIER OF THE CONUS WHERE DYNAMICAL MODEL  
GUIDANCE IS IN GENERAL AGREEMENT. ABOVE NORMAL PRECIPITATION IS ALSO FAVORED  
ACROSS PARTS OF WESTERN MAINLAND ALASKA, WHERE NATURAL ANALOG COMPOSITES DEPICT  
ENHANCED MOIST SOUTHWESTERLY MID-LEVEL FLOW. EC OF ABOVE, NEAR, AND BELOW  
NORMAL PRECIPITATION ARE INDICATED FROM CALIFORNIA EASTWARD TO MUCH OF THE  
CENTRAL AND SOUTHERN PLAINS, PARTS OF THE LOWER MISSISSIPPI VALLEY AND  
SOUTHEAST, COASTAL AREAS OF THE MID-ATLANTIC AND NORTHEAST, AND FOR MUCH OF  
ALASKA DUE TO WEAK OR CONFLICTING DYNAMICAL AND STATISTICAL GUIDANCE.  
 
FORECASTER: SCOTT HANDEL  
 
THE CLIMATIC NORMALS ARE BASED ON CONDITIONS BETWEEN 1991 AND 2020, 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 MAR ... WILL BE ISSUED ON THU FEB 16 2023  
 
THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1991-2020 BASE PERIOD.  

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page