Climate Prediction Center - Week 3-4 Outlook

Prognostic Discussion for Week 3-4 Temperature and Precipitation Outlooks
NWS Climate Prediction Center College Park MD
300PM EST Fri Jan 16 2026

Week 3-4 Forecast Discussion Valid Sat Jan 31 2026-Fri Feb 13 2026

La Niña conditions persist with below-average sea surface temperatures (SSTs) observed across the equatorial east-central Pacific and enhanced (suppressed) convection over the Maritime Continent (equatorial central Pacific). During early January, the Madden-Julian Oscillation (MJO) strengthened with a more coherent wave-1 pattern of anomalous upper-level divergence over the Pacific and anomalous upper-level convergence shifting east from the Atlantic to the Indian Ocean. From January 9 to 15, the amplitude of the Realtime Multivariate MJO (RMM) index increased in phase 6 (West Pacific). Dynamical model RMM index forecasts remain consistent and in good agreement that the MJO propagates eastward over the Western Hemisphere during the latter half of January. Given the good model agreement and continuity along with low ensemble spread, the MJO influence on the mid-latitude circulation pattern was a major factor in the Week 3-4 Temperature Outlook. The multivariate linear regression tool which includes MJO forcing was given considerable weight in the manual forecast blend. Lagged MJO composites, from phases 6 and 7, would favor anomalous cold across the eastern two-thirds of the contiguous U.S. (CONUS). The Weeks 3-4 Temperature and Precipitation Outlooks, valid January 31-February 13, were also based on dynamical model forecasts (CFS, GEFS, ECMWF, and JMA) and typical La Niña influences during the winter.

During mid to late January, a negative phase of the Arctic Oscillation (AO) is likely to continue with the dynamical models depicting positive (negative) 500-hPa height anomalies over the high (middle) latitudes of the Northern Hemisphere. The predicted MJO evolution would favor this -AO persisting into early February and anomalous cold across the north-central and eastern CONUS. Therefore, the Weeks 3-4 Temperature Outlook hedged colder than the dynamical model output from the Great Plains to the East Coast. Based on -AO and MJO composites along with the calibrated GEFS, ECMWF, CFS, and JMA temperature forecasts, below-normal temperatures are favored (33-50 percent chane) for the Midwest, Mid-Atlantic, and Northeast. The manual blend depicts a mean 500-hPa ridge axis centered near the West Coast with positive height anomalies over the western CONUS. This longwave pattern yields an increased chance of above normal temperatures across parts of Oregon, California, the Southwest, and Rio Grande Valley. Although the predicted longwave pattern along with the dynamical model output would also favor above-normal temperatures further East to include the Great Plains, equal chances (EC) of below, near, or above-normal temperatures are forecast for this region. Forecast uncertainty is high for the Great Plains as positive 500-hPa height anomalies over the high latitudes of North America may promote an Arctic air outbreak during early February. In addition, MJO composites favor a much colder outcome than the dynamical model output.

An amplified 500-hPa trough over eastern North America, most prominent in the GEFS and JMA models, would suppress the typical La Niña storm track south of the Ohio Valley. Consistent with the Weeks 3-4 Temperature Outlook along with support from the dynamical model consensus, an increased chance of below-normal precipitation extends from the Northeast to the Upper Ohio Valley. The predicted longwave pattern would favor even a larger area with a dry tilt across the Ohio Valley, but consistency with the February Precipitation Outlook (released on January 15) was considered. The anomalous 500-hPa trough over the north-central Pacific and enhanced Pacific flow leads to elevated above-normal precipitation probabilities from the Pacific Northwest east to the Northern Rockies. The wet tilt extends east to the High Plains of Montana and Wyoming with an expectation of upslope flow later in the outlook period. A large coverage of EC was warranted for a majority of the lower 48 states due to weak or conflicting signals among the dynamical model output.

The GEFS, CFS, and ECMWF models are in good agreement with an amplified 500-hPa trough (ridge) over the Aleutians (eastern Mainland Alaska or western Canada). This predicted longwave pattern and enhanced southwesterly flow supports an increased chance of above-normal precipitation and temperatures across southern Mainland Alaska.

Calibrated dynamical model output and positive SST anomalies favor above-normal temperatures for Hawaii. Based on the manual blend, the precipitation outlook leans slightly towards the wet side across Hawaii.

Forecaster: Brad Pugh

The next week 3-4 outlook will be issued on Friday, Jan 23, 2026

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

These are three category outlooks consistent with what is currently used for the monthly and seasonal forecasts.

The shading on the temperature map depicts the most favored category, either above-normal (A), below-normal (B), or near-normal (N) with the solid lines giving the probability ( >33%) of this more likely category (above, below, or near).

The shading on the precipitation map depicts the most favored category, either above-normal (A), below-normal (B), or near-normal with the solid lines giving the probability ( >33%) of this more likely category (above, below, or near).

In areas where the likelihoods of 2-week mean temperatures and accumulated precipitation amounts are similar to climatological probabilities, equal chances (EC) is indicated.