Prognostic Discussion for Monthly Outlook
NWS Climate Prediction Center College Park MD
300 PM EST Wed Jan 31 2024


30-DAY OUTLOOK DISCUSSION FOR FEBRUARY 2024

The updated February 2024 monthly temperature and precipitation outlooks are 
based on the latest dynamical model guidance, including the CFSv2 and GEFSv12 
forecasts for the month of February, as well as the Weather Prediction Center 
(WPC) temperature and precipitation forecasts for the first week of the month, 
the CPC 6-10 day and 8-14 day temperature and precipitation outlooks, and the 
latest CPC week 3-4 outlook (valid February 10-23). Although the ongoing El 
Niño is predicted to weaken over the next few months, it remains a major 
climate driver impacting the mid-latitude circulation and February temperature 
and precipitation. The Madden-Julian Oscillation (MJO) is currently active with 
enhanced convection over the Western Pacific. However, dynamical models, 
including the ECMWF and GEFS, indicate large uncertainties in the MJO forecast 
and somewhat stationary convection, as the subseasonal variability interacts 
with the El Niño circulation pattern. The MJO was only considered in the 
monthly outlook to the extent that impacts may be associated with variability 
in the dynamical model forecasts for the first two weeks of February. 

A low pressure system is expected to impact the west coast of the contiguous US 
(CONUS) during the first week of the month. Dynamical model forecasts from the 
GEFS and ECMWF ensemble prediction systems predict the mid-level trough near 
the Pacific coast at the start of February to move eastward into the 
southwestern CONUS and weaken during the second week of the month. The most 
recent available ECMWF and GEFS ensemble forecasts predict a positive 500-hPa 
height anomaly extending from Mainland Alaska southward into the western CONUS 
in the third week of February, with a negative 500-hPa height anomaly centered 
over the Northeast. There is significant uncertainty in dynamical model 
forecasts for the end of February, with generally negative 500-hPa height 
anomalies extending across the southern tier of the CONUS in most model 
solutions, positive 500-hPa height anomalies over Alaska, and the CFS 
predicting positive 500-hPa height anomalies extending across the northern tier 
of the CONUS, consistent with the mid-latitude circulation pattern associated 
with El Niño. 

The February outlook slightly favors above normal temperatures across Alaska, 
excluding the western Aleutians, as dynamical model forecasts predict a rapid 
change from likely below normal temperatures in early to mid-February to 
positive 500-hPa height anomalies, southerly flow, and above normal 
temperatures in place during the second half of the month. Above normal 
temperatures are likely across most of the northern CONUS and southward over 
the central CONUS into Northern Texas, consistent with dynamical model 
probability forecasts for the full month from the GEFS and CFS. Probabilities 
for above normal temperatures exceed 70 percent for most of the Northern 
Plains. Near normal temperatures are favored for parts of the Southwest, where 
temperatures are likely to be near-to-below normal early in the month and 
near-to-above normal later in the month, as forecast by the GEFS. Near normal 
temperatures continue to be favored for coastal areas of the Southeast, 
including the Florida Peninsula, where decadal temperature trends are positive, 
while negative temperature anomalies are correlated with El Niño conditions. 

The February outlook favors above normal precipitation for the southern coast 
of Mainland Alaska, supported by dynamical model forecasts for later in 
February and correlations with El Niño conditions. Below normal precipitation 
is favored for the Pacific Northwest and across much of the Midwest and 
Northeast, consistent with canonical impacts of El Niño and recent CFS 
dynamical model forecasts for February. A high probability of above normal 
precipitation, exceeding 60 percent in some areas, is forecast in the February 
outlook for much of Southern California, Nevada, and western Arizona, supported 
by model predictions of substantial precipitation for the first week of the 
month, that may exceed the climatological threshold for above normal 
precipitation amounts for February. Above normal precipitation is favored 
eastward across the Southwest, and northeastward into the Central Plains, as 
far north as Wyoming and South Dakota, with enhanced probabilities of 
precipitation during the first half of February. Probabilities for above normal 
precipitation exceed 50 percent for parts of the Central Plains, where 
climatological precipitation amounts are relatively low and may be exceeded 
early in the month. Above normal precipitation is slightly favored for the 
Southern Plains, where the outlook for the second half of February favors above 
normal precipitation. Above normal precipitation continues to be favored along 
the Gulf of Mexico and southern Atlantic coasts, consistent with recent 
dynamical model forecasts and the impacts of El Niño. 

******* Previous discussion, released on January 18, is below  *******

The February 2024 monthly temperature and precipitation outlooks are made with 
strong current El Niño climate conditions. The most recent weekly and seasonal 
Niño 3.4 sea surface temperature (SST) anomalies are both at +1.9 degrees 
Celsius. SST anomalies over the central and east-central equatorial Pacific 
Ocean have remained steady over the last month, while positive SST anomalies 
over the far eastern equatorial Pacific have weakened slightly. In recent 
weeks, lower level wind anomalies at 850 hPa were westerly over the 
east-central equatorial Pacific Ocean, while upper level wind anomalies at 200 
hPa were easterly over the east-central and eastern equatorial Pacific Ocean. 
Negative outgoing longwave radiation (OLR) anomalies are present near the Date 
Line and north of the equator over the eastern Pacific Ocean, indicating 
anomalously enhanced convection. These ocean and atmosphere conditions indicate 
that the ongoing strong El Niño is well coupled to the atmosphere. El Niño 
remains a primary driver of temperature and precipitation patterns over North 
America in the near future and in the February temperature and precipitation 
outlooks. On subseasonal timescales, the Madden Julian Oscillation (MJO) is 
active in phase 4 with enhanced convection over the Maritime Continent, with 
dynamical model forecasts indicating that the MJO will propagate eastward into 
the western Pacific in the next couple weeks. Lagged composites indicate that 
this active MJO would increase temperatures over the eastern United States in 
the next couple weeks, before returning to potentially cooler temperatures, 
especially over the Northeast, in early February. Impacts of the MJO were 
generally only considered in the February monthly outlook through dynamical 
model forecasts for the week 3-4 period that overlap with the first half of 
February. 

The February temperature and precipitation outlooks were based primarily on a 
skill-weighted consolidation of dynamical model forecasts and a combined 
consolidation of the statistical and dynamical model forecasts. Dynamical model 
forecasts for the month of February are from the North America Multimodel 
Ensemble (NMME). In addition, the full consolidation includes a consolidation 
of the statistical models: the Canonical Correlation Analysis (CCA), the 
Constructed Analog (CA), and an ENSO OCN tool, that combines the impact of 
ENSO, based on the CPC SST consolidation predicted median Niño 3.4 SST anomaly, 
with the Optimum Climate Normal (OCN) representing decadal trends. Daily 
initialized forecasts from the NCEP CFSv2 dynamical model, the most recent 
ECMWF and GEFS dynamical model forecasts for the week 3-4 period that overlaps 
the beginning of the month of February, and a statistical multivariate linear 
regression (MLR) forecast for the first half of February using the current Niño 
3.4 and MJO indices as predictors, were also considered. Recent boundary 
conditions, including coastal SSTs, snow cover anomalies, and soil moisture 
anomalies, were additional factors considered. 

The February temperature outlook favors above normal temperatures over all of 
Alaska, consistent with dynamical model guidance and the monthly temperature 
consolidation. Above normal temperatures are more likely for the south coast of 
Mainland Alaska and Southeast Alaska, consistent with canonical El Niño 
impacts. Above normal temperatures are favored across the northern tier of the 
contiguous U.S. (CONUS), supported by the consolidation of statistical and 
dynamical forecast tools. Probabilities for above normal temperatures exceed 50 
percent over the Pacific Northwest, due to strong signals in the NMME 
consolidation. Equal chances (EC) of below, near and above normal temperatures 
are indicated in the February outlook across much of the southern tier of the 
CONUS, due to conflicting signals from El Niño impacts and dynamical models. 
The outlook indicates enhanced probabilities of near-normal temperatures for 
parts of southeastern New Mexico, most of southern Texas, and for parts of the 
Southeast, consistent with the consolidation forecast and NMME probabilities. 
For the Southeast, decadal temperature trends are positive, while negative 
temperature anomalies are correlated with El Niño conditions. 

The February precipitation outlook favors above normal precipitation for much 
of the south coast of Mainland Alaska and the northern Alaska Panhandle, 
supported primarily by dynamical model forecasts from the NMME and correlation 
of seasonal precipitation to Niño 3.4 SST anomalies. Above normal precipitation 
is favored from Central and Southern California northeastward into parts of 
Nevada, Utah and Arizona, consistent with canonical El Niño impacts, dynamical 
model forecasts from CFSv2 for February, and dynamical model forecasts from the 
ECMWF and GEFS models for the first half of February. Negative decadal 
precipitation trends damp probabilities for above normal precipitation over 
this region. Above normal precipitation is also favored along the Gulf Coast 
and likely for parts of the Southeast, including the Florida Peninsula, where 
correlations of precipitation and the Niño 3.4 SST index are greatest. Below 
normal precipitation is favored from the Central Mississippi Valley, across the 
Ohio Valley, the eastern Great Lakes region, and over northern areas of New 
England, consistent with the CFSv2 model forecasts for February, and ECMWF and 
GEFS model forecasts for the first half of February. 

FORECASTER: Dan Collins

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 15 2024

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