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 Mar 07 2025

Week 3-4 Forecast Discussion Valid Sat Mar 22 2025-Fri Apr 04 2025

La Niña conditions are currently present and an advisory is in effect. Equatorial sea surface temperatures (SSTs) are near-to-below average in the central and east-central Pacific Ocean. SSTs are above average in the eastern Pacific Ocean. La Niña conditions are expected to persist in the near-term, with a transition to ENSO-neutral likely during March-May 2025 (66% chance).

The global tropical propagation of the Madden Julian Oscillation (MJO) has been erratic lately as multiple modes of variability have interfered with each other. However, while a wave-2 structure has begun to emerge in recent days, the models disagree on the amplitude of this signal with GEFS and CFS propagating an enhanced MJO, and ECMWF suppressing any convection ahead of the weeks 3-4 outlook period.

An equal blend of the dynamical forecast guidance for the weeks 3-4 period indicates that a trough off the southern coast of Alaska, and an elongated ridge across CONUS, are expected to influence the 500-hPa height pattern. The guidance varies on the placement of the trough with CFS, GEFS, and JMA generally centering the trough minimum over Alaska's Panhandle, as ECMWF shifts the trough minimum over the Hudson Bay. The guidance also disagrees on the placement of the ridge maximum with CFS and GEFS placing it over the eastern seaboard and JMA and ECMWF placing it further off shore over the North Atlantic Ocean.

The dynamical guidance agrees on above average temperatures across the eastern two-thirds of CONUS. Disagreement is greatest across the West Coast where ECMWF and JMA forecast weak-to-moderate chances of above average temperatures and CFS and GEFS forecast weak-to-moderate chances of below average temperatures. Given the disagreement among the forecast guidance, Equal Chances (EC) are forecast primarily west of the Rocky Mountains. All models agree on enhanced chances of below average temperatures for Alaska, with the exception of ECMWF which forecasts elevated chances of above average temperatures for the Southern Mainland of Alaska. Given the different guidance from ECMWF, chances of below average temperatures are lowest along the South Coast.

Dynamical guidance agrees on wetter than average conditions for the Pacific Northwest and for the Great Lakes, Upper Mississippi Valley, and Ohio Valley. While the guidance agrees on drier than average conditions for a broad area in the middle of CONUS, they disagree on where, and to what extent, that dry signal covers. CFS and GEFS center the driest signal over the Colorado and Oklahoma border and beyond to the Four Corners region and the border with Mexico. Meanwhile JMA moves the driest area to the Colorado and Wyoming border but forecasts the largest extent of below average precipitation that extends from Wisconsin to southern California. ECMWF forecasts a broad area of mixed, weak probabilities. Given the dynamical guidance, slightly elevated chances of drier than average conditions are forecast for the southern Plains and Four Corners region. Dynamical model guidance agrees on drier than average conditions across Alaska with the highest confidence in this signal located over the central interior of the state.

For Hawaii, surrounding SST anomalies are above normal. The temperature outlook favors above normal temperatures for all the islands. Precipitation is forecast to be drier than average for Hilo, near normal for Kahului, and wetter than average for Honolulu and Lihue.

Temperature Precipitation

FCST FCST

Hilo A55 B 5

Kahului A60 EC

Honolulu A55 A55

Lihue A55 A55

Forecaster: Emerson LaJoie

The next week 3-4 outlook will be issued on Friday, Mar 14, 2025

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

These are two category outlooks and differ from official current three category outlooks currently used for the monthly and seasonal forecasts.

The shading on the temperature map depicts the most favored category, either above-normal (A) or below-normal (B) with the solid lines giving the probability ( >50%) of this more likely category (above or below).

The shading on the precipitation map depicts the most favored category, either above-median (A) or below-median (B) with the solid lines giving the probability ( >50%) of this more likely category (above or below).

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