Prognostic Discussion for Monthly Outlook
NWS Climate Prediction Center College Park MD
830 AM EST Thu Jan 19 2023


30-DAY OUTLOOK DISCUSSION FOR FEBRUARY 2023

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.

An updated monthly outlook... for Feb will be issued on Tue January 31 2023

These outlooks are based on departures from the 1991-2020 base period.
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