Prognostic Discussion for Monthly Outlook 
NWS Climate Prediction Center College Park MD 
300 PM EDT Sat May 31 2025 
 
 
30-DAY OUTLOOK DISCUSSION FOR JUNE 2025 
 
The updated June Temperature and Precipitation outlooks are based on the latest 
dynamical models, WPC temperature and precipitation forecasts during the first 
week of the month, the CPC 8-14 day temperature and precipitation outlooks, and 
the week 3-4 outlook (valid June 14-27). Soil moisture influence and its 
constructed analog are also factors in the updated June outlook. During late 
May, the Madden-Julian Oscillation (MJO) began to strengthen as the 200-hPa 
velocity potential anomaly field became more coherent and wave-1 spatially with 
anomalous upper-level divergence (convergence) over the Maritime Continent 
(Atlantic and Africa). The ECMWF and GEFS model forecasts depict the Real-time 
Multivariate MJO index gaining amplitude and moving through phases 6, 7, and 8 
during early to mid-June. If the MJO continues to propagate eastward over the 
Western Hemisphere, then the large-scale environment would become favorable for 
tropical cyclone (TC) development initially across the East Pacific and then 
expand to the Caribbean Sea later in June. Prior to this favorable MJO 
response, recent dynamical model solutions and especially the GFS model have 
depicted TC genesis across the western Caribbean Sea during early June. 
 
A cut-off low near the northern Baja Peninsula will steer high anomalous 
moisture, associated with Tropical Depression Alvin in the East Pacific, 
northward to the Desert Southwest on June 1. An unusual wet start to June is 
forecast for this region with WPC depicting widespread precipitation totals of 
0.25 to 1 inch. Model solutions remain consistent that precipitation amounts 
are likely to be enough to warrant large above-normal precipitation 
probabilities (more than 60 percent) across Arizona to southern Utah since June 
is a relatively dry month. This anomalous moisture, interacting with a front, 
is also expected to result in heavy precipitation across much of Colorado and 
northern New Mexico early in June, favoring enhanced above-normal precipitation 
probabilities. Another area that is forecast to have a wet start to the month 
is southeastern Kansas, southwestern Missouri, and Oklahoma with WPC 
forecasting more than 3 inches of precipitation during the first week of June. 
Therefore, above-normal precipitation probabilities are maximized for those 
areas. Based on the WPC 7-day precipitation forecast, CPC 8-14 day outlook, 
Week 3-4 outlook, and the constructed analog from soil moisture, above-normal 
precipitation is favored for much of the Central to Southern Great Plains, 
Middle to Lower Mississippi Valley, and Southeast. The increased chance of 
above-normal precipitation for the Southeast is also consistent with the 
expectation that the MJO would favor TC development across the western 
Caribbean later in June. Conversely, precipitation tools at all time scales 
support elevated below-normal precipitation probabilities extending from the 
Pacific Northwest east to the Northern Great Plains This favored dryness is 
related to a 500-hPa ridge that is forecast to persist either over or upstream 
from these areas. Due to weak or conflicting signals  among the model guidance, 
equal chances (EC) of below, near, or above-normal precipitation are forecast 
for the Midwest and Northeast. EC is also forecast for much of Alaska with only 
a slight lean towards above-normal precipitation forecast across parts of 
southeastern Alaska. 
 
Since the initial June outlook was released on May 15th, model solutions have 
remained consistent that a majority of the lower 48 states are more likely to 
have a warmer-than-normal June. However, the one exception and where EC is 
forecast includes parts of the Central to Southern Great Plains, Ozarks region, 
and Lower Mississippi Valley, due to ongoing high soil moisture (above the 70th 
percentile) and favored wetness during the next month. For the Southeast, 
above-normal temperature probabilities are limited due to the expectation of a 
wetter-than-normal June but the outlook leans on the warmer side with early to 
mid-June favored to have above-normal temperatures. In contrast to the 
likelihood of a warmer-than-normal June for most of the lower 48 states, 
anomalous cold early in the month leads to an increased chance for below-normal 
temperatures for Alaska. Later in the month, the ECENS and GEFS depict a 
weakening of the persistent 500-hPa trough over Alaska which would lead to 
moderating temperatures. Therefore, the updated June outlook only slightly 
leans towards below-normal temperatures for Alaska. The highest forecast 
confidence in the updated June outlook, with above-normal temperature 
probabilities exceeding 50 percent, includes the Northeast and parts of the 
West where temperatures are forecast to average 5 to 10 degrees F above normal 
during the first week of the month and model solutions favor this anomalous 
warmth continuing through at least mid-June. 
 
 
***************************************************************************** 
 Previous mid-month discussion below 
***************************************************************************** 
 
 
The June 2025 Temperature and Precipitation Outlooks are based on the: North 
American Multi-Model Ensemble (NMME) and International Multi-Model Ensemble 
(IMME), consolidation (statistical and dynamical tools), soil moisture 
influence and its constructed analog, and decadal trends . The Madden-Julian 
Oscillation (MJO) remains weak and dynamical model spread is high on whether 
the MJO may strengthen heading into June. Although the MJO is unlikely to 
affect the mid-latitude circulation pattern during June, it will be closely 
monitored as it could contribute to a more favorable environment for an early 
season tropical cyclone in the Atlantic basin. ENSO-neutral conditions are 
forecast to continue throughout June. 
 
The highest forecast confidence in the temperature outlook is for above-normal 
temperatures (probabilities greater than 60 percent) across the Southwest, 
based on the calibrated NMME, warming influence from low soil moisture, and 
consistent with decadal trends . The June outlook reflects the NMME and IMME 
with their decreasing above-normal temperature probabilities farther to the 
north over the West. Probabilities are also lower across much of Oklahoma and 
northeastern Texas where high soil moisture (above the 90th percentile) would 
have a cooling effect on surface temperatures in the coming weeks. In addition, 
a constructed analog derived from soil moisture depicts a weak cold signal. The 
NMME and the decadal trend support an increased chance of above-normal 
temperatures for most of the East with the largest probabilities (exceeding 50 
percent) forecast across the Florida Peninsula. Due to little or no signal in 
the NMME and a more neutral trend, equal chances (EC) of below, near, or 
above-normal temperatures are forecast for parts of the Northeast and Great 
Lakes. Consistent with the NMME and decadal trends , above-normal temperatures 
are more likely across the southern tier of Alaska with EC forecast for the 
northern two-thirds of Mainland Alaska. 
 
Based on the NMME, IMME, constructed analog from soil moisture, and trend, 
below-normal precipitation is favored for parts of the Pacific Northwest, 
northern Intermountain West, Great Basin, Rockies, and High Plains. The largest 
below-normal precipitation probabilities (greater than 40 percent) extend from 
Idaho and southwestern Montana southeastward to the southern High Plains where 
the dynamical model output and statistical tools are in the best agreement. In 
the climatologically drier areas of California and the Southwest, EC is 
forecast. The constructed analog using sea surface temperatures depicts a wet 
signal for the Southwest, implying an early, robust start to the Monsoon. This 
would also be consistent with ongoing low soil moisture for the Southwest. 
However, forecast confidence was not high enough at this time to lean towards 
above-normal precipitation, given the lack of dynamical model support, but this 
region will be reevaluated for the update released on May 31st. A broad area 
with EC covers much of the Great Plains and Mississippi Valley due to a weak 
signal among the precipitation tools along with large uncertainty in predicting 
areas of anomalous convective rainfall at a half-month lead. A slight lean 
towards above-normal precipitation is forecast for the East and parts of the 
Great Lakes with the NMME, IMME, constructed analog from soil moisture, and 
trend at least having a weak signal for a wetter-than-normal June. For Alaska, 
above-normal precipitation is most likely across southeastern parts of the 
state which is supported by the NMME and trend. 
 
FORECASTER: Brad Pugh 
 
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 Jul ... will be issued on Thu Jun 19 2025 
 
These outlooks are based on departures from the 1991-2020 base period. 
$$