Prognostic Discussion for Monthly Outlook 
NWS Climate Prediction Center College Park MD 
300 PM EDT Sun May 31 2026 
 
 
30-DAY OUTLOOK DISCUSSION FOR JUN 2026 
 
The updated June 2026 Monthly Outlook is based on the latest dynamical model 
guidance, including CFSv2 forecasts for the month of June, as well as the 
Weather Prediction Center (WPC) temperature and precipitation forecasts for the 
first week of the month, the Climate Prediction Center (CPC) 6-10 day and 8-14 
day temperature and precipitation outlooks, and the latest CPC Week 3-4 Outlook 
(valid June 13-26). Dynamical model forecasts from the ECMWF were also 
consulted for weeks 2 through 4. 
 
Transition to an El Nino background state appears under way over the equatorial 
Pacific and could possibly impact the climate of North America in June. The 
latest weekly Nino 3.4 index is +0.5 degrees Celsius. Weak El Nino conditions 
are likely to be present for the three month season centered on June, with a 
probability exceeding 80 percent. The Madden Julian Oscillation (MJO) 
convective phase propagated across the Maritime Continent and amplified over 
the Western Pacific, as it interacted with the emerging El Nino signal. 
Dynamical model forecasts, including the ECMWF, predict a deamplification of 
the MJO signal as it propagates eastward out of the Western Pacific. Impacts of 
tropical variability were primarily considered in the updated June Monthly 
Outlook through canonical seasonal impacts of the likely El Nino state, in 
addition to the dynamical model forecasts of tropical impacts on the climate of 
North America. 
 
The updated June temperature outlook favors below normal temperatures for the 
Alaska Peninsula, the southwestern and western southern coasts of Mainland 
Alaska, and islands in the southeastern Bering Sea and western Gulf of Alaska, 
due to negative sea surface temperature (SST) anomalies in adjacent waters and 
consistent with recent ECMWF dynamical model forecasts for weeks 1 through 4. 
Above normal temperatures continue to be favored for central and eastern 
interior Mainland Alaska and Southeast Alaska, consistent with recent CFSv2 
forecasts for June, as well as ECMWF model forecasts for the first half of June 
and week 4. Above normal temperatures continue to be likely across the western 
contiguous United States (CONUS) from the Pacific coast to the Rocky Mountains, 
consistent with dynamical model guidance and CPC and WPC outlooks for all 
timescales. Elevated probabilities of above normal temperatures exceeding 60 
percent across much of the northwestern interior are also supported by negative 
correlations between precipitation and temperature. Above normal temperatures 
are favored across the northern central and northeastern CONUS in the updated 
June Monthly Outlook, consistent with WPC temperature forecasts for the first 
week of June, the CPC forecast for week 2, and the CFSv2 temperature forecast 
for the month. Equal chances of below, near and above normal temperatures are 
forecast for most of the southern central and southeastern CONUS, where 
temperatures are forecast to be near or below normal early in the month and 
below normal in the latest CPC Week 3-4 Outlook for the southern central CONUS. 
Above normal temperatures are likely for the southern Florida Peninsula in 
June, consistent with the CFSv2 forecast and ECMWF model forecasts for weeks 1 
through 4. 
 
The updated June precipitation outlook favors above normal precipitation for 
eastern Mainland Alaska, consistent with the CPC Week 2 Outlook and ECMWF 
forecasts for weeks 3 and 4. Below normal precipitation is favored for far 
southern Southeast Alaska and most of the northwestern CONUS, consistent with 
the CFSv2 forecast, model forecasts for early June, and the CPC Week 3-4 
Outlook. Above normal precipitation is favored from eastern areas of the 
Southwest northeastward into parts of the Central Plains, consistent with the 
CPC Week 2 and Week 3-4 Outlooks, and the WPC precipitation forecast for the 
first seven days of June. Probabilities are enhanced to exceed 50 percent for 
parts of New Mexico and West Texas, where predicted precipitation amounts for 
the first week of the month are near the climatological threshold for above 
normal precipitation for the entire month. The updated June precipitation 
outlook favors below normal precipitation for most of the Great Lakes region 
and northern New York and New England, consistent with model precipitation 
forecasts for the first week of June and recent CFSv2 precipitation forecasts 
for the month. Above normal precipitation is favored for most of the Gulf Coast 
states and the Southeast Atlantic coast, consistent with the CFSv2 
precipitation forecast for June and ECMWF forecasts for the first half of the 
month. 
 
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***** Previous mid-month discussion below 
 ***** 
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The June 2026 Monthly Outlook was made with El Nino conditions expected to 
develop by this summer. The most recent weekly Nino 3.4 sea surface temperature 
(SST) anomaly is about +0.5 degrees Celsius, corresponding to the threshold 
between ENSO-neutral and El Nino. Positive SST anomalies in the central and 
eastern equatorial Pacific Ocean are greater than in the Nino 3.4 region. 
Outgoing longwave radiation (OLR) anomalies were positive over the far western 
Pacific Ocean, associated with suppressed convection and precipitation over 
parts of the Maritime Continent. Negative OLR anomalies, indicating enhanced 
convection and precipitation, were present near the International Date Line to 
the north of the equator, consistent with developing El Nino conditions. 
Low-level (850-hPa) easterly trade winds were near average across the 
equatorial Pacific. Upper-level (200-hPa) wind anomalies were westerly over the 
central and eastern equatorial Pacific Ocean in recent weeks. Positive 
subsurface ocean temperature anomalies increased in magnitude near the surface 
in the central and eastern equatorial Pacific Ocean, increasing the likelihood 
and potential strength of an El Nino. Dynamical model forecasts and the CPC El 
Nino Southern Oscillation (ENSO) Outlook predict El Nino conditions are likely 
to be weak for the May-June-July season with a probability slightly greater 
than 70 percent. El Nino conditions are most likely to strengthen in the summer 
and autumn seasons. Although potential El Nino conditions are likely to be weak 
and not impact the predictability of the June climate outlook, subseasonal 
forcing and tropical-extratropical teleconnections may impact the outlook. 
 
The Madden Julian Oscillation (MJO) has begun to propagate with enhanced 
convection currently over the eastern Indian Ocean. Dynamical models , including 
the ECMWF, predict the propagation of the MJO signal eastward into and across 
the Western Pacific in early June. The MJO in this phase enhances the chances 
of cooler conditions over the east-central contiguous United States (CONUS) in 
early June extending into the Northeast with time. The combined influence of 
the MJO, the current state of ENSO, and decadal trends  were considered in the 
June climate outlook, using a multivariate linear regression (MLR) statistical 
model. 
 
The June temperature and precipitation outlooks were based primarily on 
dynamical model and statistical model forecasts. Dynamical model forecasts for 
the month of June are from the North America Multimodel Ensemble (NMME) and the 
International Multimodel Ensemble (IMME). In addition to the NMME, a 
consolidation of model forecasts was utilized, which includes the following 
statistical tools: 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 Nino 3.4 SST anomaly, with the 
Optimum Climate Normal (OCN) to represent decadal trends . Daily initialized 
forecasts from the Climate Forecast System (CFSv2) dynamical model for the 
month of June and the most recent ECMWF dynamical model forecasts for the week 
3-4 period that is valid for June 2-15 were also considered. Recent boundary 
conditions, including coastal SSTs and soil moisture anomalies, were additional 
factors considered in the outlook. 
 
The June outlook favors below normal temperatures for the Alaska Peninsula, 
coastal southwestern Mainland Alaska, and islands in the southeastern Bering 
Sea, due to negative SST anomalies in the adjacent waters and consistent with 
dynamical model forecasts from the IMME and CFSv2. Above normal temperatures 
are favored for most of the remainder of Mainland Alaska and for Southeast 
Alaska, consistent with dynamical model forecasts from the NMME, IMME and 
CFSv2, as well as the combined impacts of developing El Nino conditions and the 
predicted propagation of the MJO into the Western Pacific. Above normal 
temperatures are favored across the western CONUS from the Pacific coast to the 
Rocky Mountains and High Plains, across the Central Plains and much of the 
Southern Plains, into the Central and Lower Mississippi Valley, the Ohio 
Valley, Mid-Atlantic, and Southeast. Probabilities exceed 60 percent over much 
of the northwestern CONUS, consistent with recent temperature forecasts from 
the CFSv2, the consolidation, and decadal trends . Probabilities for above 
normal temperatures for this region are also enhanced by the correlation 
between predicted below normal precipitation and above normal temperatures. 
Probabilities favoring above normal temperatures exceed 50 percent over the 
Southeast Atlantic coast, consistent with most dynamical model forecasts for 
June and ECMWF and MLR forecasts for the first half of the month. Equal chances 
of below, near, and above normal temperatures are forecast for the 
north-central and northeastern CONUS, due to uncertainty in temperature 
forecast tools for the first half of June and low predictability as indicated 
by the calibrated NMME forecasts. 
 
The June outlook favors above normal precipitation for northwestern Mainland 
Alaska, consistent with NMME and IMME anomaly forecasts, the consolidation of 
dynamical and statistical model precipitation forecasts, and decadal trends . 
Below normal precipitation is favored for Southeast Alaska, consistent with 
dynamical model forecasts for June and the MLR and ECMWF forecasts for early 
June. Below normal precipitation is favored over much of the northwestern CONUS 
from the Pacific Northwest to the northern Rockies, consistent with the CFSv2 
forecast for June, the ECMWF forecast for the first half of the month, and 
decadal trends . Above normal precipitation is favored for much of the 
Southwest, central Rockies, and southern High Plains, as well as for much of 
the Southeast, consistent with NMME, IMME, and CFSv2 dynamical model forecasts 
for June, as well as ECMWF forecasts for the first half of June. Equal chances 
of below, near, and above normal precipitation is indicated for the remainder 
of the CONUS, where there is greater variability among precipitation forecast 
tools. 
 
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 Jul ... will be issued on Thu Jun 18 2026 
 
These outlooks are based on departures from the 1991-2020 base period. 
$$