NOAA Updates its March Outlook on February 28, 2025

Unexplained shift in the temperature pattern to the east and up into the Northern Great Plains.

PART I

At the end of every month, NOAA updates its Outlook for the following month which in this case is March of 2025. We are reporting on that tonight. In this article, I refer to March 2025 as "The New Month".

There have been some significant changes in the temperature Outlook for the new month compared to the Mid-Month Outlook.

Changes made are addressed in the NOAA Discussion so it is well worth reading. We provided the prior Mid-Month Outlook for the new month for comparison. It is easy to see substantial changes made to the weather outlook by comparing the Mid-Month and Updated Maps.

The article includes the Drought Outlook for the new month. NOAA also adjusted the previously issued three-month Drought Outlook to reflect any changes in the new month's Drought Outlook. We also provide the Week 2/3 Tropical Outlook for the World. The Tropical Outlet includes both direct and indirect potential impacts to the Southern Tier of CONUS.

The best way to understand the updated outlook for the new month is to view the maps and read the NOAA discussion. I have highlighted the key statements in the NOAA Discussion.

I am going to start with graphics that show the updated Outlook for the new month and the earlier Mid-Month Outlook for the new month. This is followed by a graphic that shows both the Updated Outlook for the new month and the previously issued Outlook for the three-month period. So you get the full picture in three graphics.

Here is the updated Outlook for March 2025.

For Comparison Purposes, Here is the earlier Mid-Month Outlook for March, 2025

It is important to remember that the maps show deviations from the current definition of normal which is the period 1991 through 2020. So this is not a forecast of the absolute value of temperature or precipitation but the change from what is defined as normal or to use the technical term climatology.

There is some significant change with respect to temperature from the Mid-Month outlook issued just 8 days ago. This then raises some questions with respect to the February 20, 2025 three-month MAM temperature Outlook which is shown in the following graphic. At this point we have not yet concluded that the MAM temperature Outlook is incorrect.

NOAA provided a combination of the Updated Outlook for the New Month and the Three-Month Outlook.

The top pair of maps are the updated outlook for the new month. There is a temperature map and a precipitation map. The bottom row shows the previously issued three-month outlooks which includes the new month. I think the outlook maps are self-explanatory.

The basic information for March is shown above. There is a lot more information in Part II of this article.

Part II

Here are larger versions of the March Temperature and Precipitation Outlook maps.

NOAA (Really the National Weather Service Climate Prediction Division CPC) Discussion.

I have shown certain important points in bold type. My comments if any are in brackets [ ].

30-DAY OUTLOOK DISCUSSION FOR MARCH 2025

The March 2025 Monthly Temperature and Precipitation Outlooks are updated with input from the Climate Prediction Center (CPC) Extended Range and Subseasonal Outlooks, dynamical model guidance for week 2 and weeks 3-4, background climate states such as the Madden Julian Oscillation (MJO) and El Niño Southern Oscillation (ENSO), recent Climate Forecast System version 2 (CFSv2) monthly forecasts of temperature and precipitation, and experimental monthly forecasts of temperature and precipitation from extended runs of the Global Ensemble Forecast System version 12 (GEFSv12) and the European Centre for Medium-Range Weather Forecasts (ECMWF) models. A La Niña Advisory is still in effect. The latest weekly sea surface temperature (SST) departures reached -0.5 degrees Celsius in the Niño 4 region and -0.3 degrees Celsius in the Niño 3 region over the last week. This is a weak La Niña event, so while we may expect some of the typical impacts, we also expect greater variability in temperature and precipitation during the month or season. The MJO has begun to weaken and stall in Phase 8, retreating back into the unit circle, due to destructive interference with equatorial Rossby wave activity and the low-frequency base state, however, dynamical model forecasts of the Realtime Multivariate MJO (RMM) index favor the return of eastward propagation of the signal, but this is also weak and there is uncertainty in models on the strength of the MJO, with GEFS favoring a stronger MJO and ECWMF keeping the MJO rather weak. Given the weakness of these drivers as well as the variability seen in shorter term forecasts, we expect a fairly transient pattern through at least the first half of March.

In the near-term forecast period (i.e. the 6-10 day and 8-14 day forecasts through about mid-March), an active, transient pattern is expected which would bring variable weather to the Contiguous United States (CONUS). In the 6-10 day period, the mean mid-level height pattern favors below normal heights across much of the eastern CONUS to the Pacific Northwest, with near normal heights favored over the West and Central CONUS. An active southern stream and associated shortwave troughing add to the transient forecast for early March. The pattern is less progressive into the week-2 period, but still active and complex. This transient pattern in the first half of March adds some uncertainty to the monthly forecast. In the Weeks 3-4 period (through approximately the end of March), models favor mid-level troughing over Alaska and the Northwest, and weak ridging over the South and East with the ridge axis favored to be off the East Coast. Overall, the March forecast is complex and variability is expected, particularly in the first half of the month.

Temperature

The updated March 2025 Temperature Outlook features below normal temperatures over the Northwest and approximately the northern half of California, and the southern two-thirds of Alaska. Above normal temperatures are favored over the Northern Plains, central CONUS, and southern U.S. including the Gulf States and parts of the southern Mid-Atlantic [Author’s Note: This pattern was considered but rejected in the Mid-Month Outlook so we do not consider the change to be other than being able to read the tea leaves better eight days later] and Southern CONUS, which leads to relatively enhanced probabilities over these regions. A significant swing in the pattern and temperatures is expected early in March over Alaska, where shorter term forecasts favor a rapid swap from above normal temperatures to below normal temperatures as troughing moves into the region, which then remains consistent into the Weeks 3-4 period. As the above normal temperatures appear to be shorter lived over Alaska, the overall March forecast has a tilt toward below normal. Swings in temperatures are also expected in the short term (early March) over the East, with periods of below normal temperatures possible, particularly for the Northeast. This gives way to ridging and above normal temperatures by the middle to end of March. Despite the variability in early March, much of the southern half of the East Coast is favored to be above normal given the forecasts for the mid to end of March given weaker signals for below normal temperatures, while Equal Chances (EC) of above, near, and below normal temperatures are favored for the Northeast where some periods of below normal temperatures are more strongly forecasted.

Precipitation

In contrast to temperatures, model forecasts have been more consistent on the precipitation signals. Mid-level troughing and onshore flow supports enhanced probabilities of above normal precipitation over parts of California and the Northwest, though there is some uncertainty on how far south the above normal precipitation will reach given dynamical models and the La Niña teleconnection that support below normal precipitation over southern California. Thus, EC of above, near, and below normal precipitation are appropriate over southern California, despite the early March above normal precipitation signal that covers much of the state. Above normal precipitation is also favored over the Great Lakes and parts of northern New England, as supported by dynamical models, and the La Niña teleconnection. Most dynamical models favor above normal precipitation over Alaska and it is the climatologically driest time of year for precipitation, as such a tilt toward above normal is indicated over much of the state. Below normal precipitation is favored over the Southwest and Southern Plains given model consistency, though most models also tilt toward below normal over the Gulf Coast and Florida consistent with what we might expect from La Niña. However, there is a chance for above normal precipitation over the Gulf States in the short term, so EC is favored. EC is also favored over the Northern Plains given weak and inconsistent signals among models and tools.

Drought Outlook

Here is the newly issued Drought Outlook for the month.

You can see where drought development or persistence is likely. The summary and detailed discussions that accompany this graphic can be accessed HERE, but the short version is shown below.

Here is the short version of the drought summary

Latest Monthly Assessment - During the past 4 weeks, periodic heavy precipitation across the Pacific West, Intermountain West and Rockies brought 1 to 2 class drought amelioration. An extreme precipitation activity also brought widespread flooding to Kentucky and portions of the Tennessee Valley and central Appalachians and resulted in some drought reduction (1 to 3 class improvement) in the regions and northeastward into many parts of Virginia. However, widespread precipitation deficits were observed across many parts of the lower 48 states. A 1 to 2 class drought degradations were seen in many parts of the Midwest and Southeast, with the largest expansion of drought occurring across the Great Basin, Four Corners states and northwestern Southern Region due to below normal precipitation coupled with generally above normal temperatures. With La Nina conditions continue to be favored in the March period, the CPC monthly outlooks favor a canonical La Nina response pattern, with drier and warmer conditions across parts of the southern tier of the CONUS, a winter storm track favoring for the Great Lakes, Tennessee-Ohio Valleys, and interior New England, and an enhanced wet month for the Northwest. Therefore, drought reduction is favored across parts of the Northwest, Midwest, Tennessee Valley and Northeast. Across the southern tier, drought persistence is favored across the existing drought over much of the Southwest with expansion is expected for portions of Arizona, New Mexico, southwestern Texas, and the Southeast.

Below normal snowpack is a concern across the southern tier of Alaska for the spring time melting. However, no drought conditions are currently present or favored to develop across Alaska for March. During the past few weeks the existing drought and abnormal dry conditions were quickly improved across much of the Hawaii Islands. March is a climatological wet season for the Islands with the La Nina conditions typically favoring enhanced rainfall across the region, but drought reduction is only likely for parts of northern islands with forecast enhanced trades for March. No drought conditions are currently present or favored to develop across Puerto Rico and the US Virgin Islands.

We also have an updated Seasonal Drought Outlook (link).

This three-month outlook forecast is a combination of the mid-month three-month drought forecast and the revised drought forecast for March.

It is a dramatic expansion of the drought.

The Tropical Forecast can Impact the Outlook in ways not reflected in the NOAA discussion. This shows the Weeks 2 and 3 Outlooks.

I do not see anything here that is very significant for the U.S. but there is a lot that is significant for other parts of the World such as Australia. To update this forecast (which updates on Tuesdays), click HERE

It is useful to review the prior month.

Month-to-date Temperature for the prior month can be found below. As we head into the new month, the month to date Temperature can be found HERE

Month-to-date Precipitation for the prior month can be found below. As we head into the new month, the month to date Precipitation can be found HERE

It looks a lot like a La Nina pattern.

I hope you found this article interesting and useful