But first I will repeat the Outlook for the next three months.

Then the following overlapping three-month periods

July through September covers the main part of the North American Monsoon (NAM) and you can see the forecasts is for a slightly better than average monsoon but the moisture is pretty much blocked from extending much beyond Arizona and New Mexico. Utah and Colorado may get some benefits as may Texas. The next map shows that the blocking high dry area continues into October.

NOAA does not provide single-month Outlooks beyond the subsequent month so it is a little hard to interpret a three-month outlook. But if you spend some time looking at these maps you get an idea of what NOAA thinks will happen. That blocking dry area north of Arizona and New Mexico which is probably a high-pressure area limits the impact of the Monsoon on other states.

NOAA Discussion

CURRENT ATMOSPHERIC AND OCEANIC CONDITIONS

Equatorial SSTs and the tropical Pacific atmosphere are consistent with La Niña. During the last 4 weeks, below average SSTs strengthened in the central Pacific Ocean, and recent observed weekly SST departures reached -1.1 degrees Celsius in the NINO3.4 region. Subsurface temperature anomalies (averaged from 180-100W and 0-300 meters) have remained negative since late February, but have been increasing since mid-March. During the last two months, negative subsurface temperature anomalies expanded across the central and eastern Pacific Ocean, while positive anomalies were observed in the western and central Pacific at depth. During the last 30 days, low-level (850-hPa) easterly wind anomalies were evident over the equatorial Pacific Ocean, with enhanced convection over the Philippines and suppressed convection over the central and Western Pacific. These observations are consistent with La Niña conditions.

The Real-time Multivariate Madden Julian Oscillation (RMM) signal recently depicted an elevated amplitude but propagation speed more consistent with a strong Kelvin Wave than a Madden Julian Oscillation (MJO) event. Forecasts of MJO evolution from the Global Ensemble Forecast System (GEFS) depicts a fast eastward propagating signal consistent with a Kelvin Wave, and large uncertainty. Forecasts of MJO evolution from the European Centre for Medium-Range Weather Forecasts (ECMWF) depict a meandering signal across the west-central Pacific, but destructive interference from La Niña is expected to limit eastward propagation.

SSTs along the southern coast of Alaska have shifted from neutral to weakly anomalously cold in recent observations, and cold SSTs have strengthened along the California coast. Gulf of Mexico SSTs, and SSTs near the New England coast remain anomalously warm. In contrast, anomalously cold SSTs are observed off the Mid-Atlantic coast.

PROGNOSTIC DISCUSSION OF SST FORECASTS

The International Research Institute for Climate and Society (IRI) / Climate Prediction Center (CPC) plume average of forecasts for the Niño-3.4 SST region from the last month depicts decreasing odds of La Niña into the late northern hemisphere summer (58% chance in August-October 2022), and increased odds through Northern Hemisphere fall and early winter 2022 (61% chance). Model guidance from the North American Multi-Model Ensemble (NMME) now hints at a strengthening of La Niña conditions again in the fall and upcoming winter. Forecaster consensus predicts borderline La Niña conditions in the Northern Hemisphere summer and increasing odds into the fall and early winter.

30-DAY OUTLOOK DISCUSSION FOR JUNE 2022

The June 2022 temperature and precipitation outlooks are based on dynamical model guidance (including the North American Multi-Model Ensemble (NMME) and the week 3-4 model solutions), statistical tools, current soil moisture conditions, and La Niña composites. The Madden-Julian Oscillation (MJO) remains weak as multiple Kelvin waves (KWs) continue to propagate rapidly eastward over the global tropics. The MJO is not expected to provide any significant influence on the mid-latitude circulation pattern across North America during June. However, the passage of KWs over the Western Hemisphere from late May into June and its potential contribution to the development of an early season tropical cyclone across the western Caribbean Sea was considered as a factor in the precipitation outlook.

Temperature

During early to mid-May, anomalous 500-hPa ridging resulted in much above normal temperatures throughout the southern Great Plains with positive anomalies of more than 6 degrees F across the western half of Texas. Although there could be brief periods of weakening of this subtropical riding, ensemble means depict the anomalous 500-hPa ridging over the southern tier of the CONUS likely persisting through the first half of June. Based on good agreement among dynamical and statistical tools, above-normal temperatures are favored across the southern two-thirds of the CONUS. The largest probabilities (above 60 percent) are forecast for western Texas and New Mexico, coinciding with the lowest soil moisture. Conversely, anomalously wet soil moisture was one reason for equal chances (EC) of below, near, or above-normal temperatures across much of the northern Great Plains and upper Mississippi Valley. Also, the calibrated NMME supports EC for the northern tier of the CONUS. The EC forecast along much of the West Coast was due in part to negative sea surface temperature anomalies nearby. The week 3-4 tools, covering the first two weeks of June, along with most of the inputs to the NMME support slightly elevated probabilities of below normal temperatures across western parts of Oregon and Washington along with the Alaska Panhandle. Due to conflicting and weak signals  among the tools, EC is forecast for the remainder of Alaska.

Pecipitation

The NMME supports elevated probabilities of below-normal precipitation across much of the central to southern Great Plains, extending westward to parts of the Great Basin, Pacific Northwest, and northern California. The slightly larger probabilities, focused from southern Wyoming southward to the Texas Panhandle, was due to La Niña composites and week 3-4 tools. Since June is typically a dry time of year for southern California and the desert Southwest, EC was forecast for these areas. Regardless of any effects from a potential early season tropical cyclone, the GEFS and ECMWF models depict broad upper-level divergence over the Gulf of Mexico and adjacent areas of the northern Gulf Coast and Florida during early to mid-June. This is expected to promote enhanced sea breeze convection. Based on this expectation and support from the NMME, above-normal precipitation is slightly favored for Florida and areas along and close to the northern Gulf Coast. For the remainder of the eastern and northern tier of the CONUS and Alaska, a large area of EC was necessary in the June precipitation outlook due to weak signals  among the dynamical model solutions. This large coverage of EC and prospects for an early season TC, potentially emerging from the western Caribbean Sea, will be reevaluated with the updated June outlook, released on May 31.

SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS (Focus  on JJA 2022)

Temperature

The June-July-August (JJA) 2022 temperature outlook depicts elevated odds of above normal seasonal mean temperatures for most of the U.S., including northern and western Alaska, with the highest probabilities over the western half of the nation. The greatest likelihood for above normal temperatures are located in the Central Great Basin through the Central and Southern Rockies. Equal chances of above, near, or below normal temperatures are forecast for the Pacific Northwest, parts of the Northern Plains and Upper Mississippi Valley where probabilities for each category of seasonal mean temperatures are expected to be similar to climatological probabilities.

Precipitation

The JJA 2022 precipitation outlook favors below normal precipitation stretching from the Pacific Northwest into the Northern Plains, and southward into the Southern Plains. Above normal precipitation is more likely for parts of Alaska, the Southwest, and the Eastern Seaboard. EC of above, near, or below normal precipitation are forecast for areas where probabilities for each category of seasonal accumulated precipitation amounts are expected to be similar to climatological probabilities.

ENSO

A La Niña advisory remains in effect and Equatorial sea surface temperatures (SSTs) are below average across most of the Pacific Ocean, and the tropical Pacific atmosphere is consistent with a La Niña. La Niña is favored to continue through the Northern Hemisphere summer (58% chance in August-October 2022), with slightly increased odds through Northern Hemisphere fall and early winter 2022 (61% chance).

BASIS AND SUMMARY OF THE CURRENT LONG-LEAD OUTLOOKS

PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS

Dynamical model forecasts from the NMME and Copernicus (C3S) multi-model ensemble systems are used extensively for the first six leads [Authors Comment: it is a surprise that they are using dynamical models that part into the outlook] when they are available as was the objective, historical skill weighted consolidation, that combines both dynamical and statistical forecast tools. Current soil moisture conditions played a role in the construction of these outlooks. Recent soil moisture content is abnormally dry for much of the southwestern Continental United States (CONUS), though recent precipitation accumulation in the Northern Plains and Upper Mississippi Valley has increased soil moisture content in these regions. Potential typical impacts known to be associated with La Niña summers are utilized in preparation of the outlook via techniques including composite analysis and regressions anchored to NINO3.4 SSTs. Statistical guidance such as the global SST based Constructed Analog (CA), experimental Calibration, Bridging, and Merging (CBaM) guidance, and long term temperature and precipitation trends  played a role in many of the outlook seasons. Coastal SSTs also are considered, especially at the early leads.

 PROGNOSTIC DISCUSSION OF OUTLOOKS – JJA 2022 TO JJA 2023

TEMPERATURE

The JJA 2022 temperature outlook favors above normal temperatures for much of the CONUS. The greatest odds for above normal temperatures (60 to 70 percent) are located over the Central Great Basin through the Central and Southern Rockies given consistency among dynamical model suites such as NMME and C3S, statistical tools, decadal temperature trends , and anomalously dry soil moisture. In contrast and at odds with warmer guidance from C3S, anomalously wet soil moisture in the Northern Plains and Upper Mississippi Valley led to EC favored for the region. EC is also favored for the Pacific Northwest, consistent with expected La Niña conditions. Elevated odds for above normal temperatures are depicted over New England reflecting decadal trends  and anomalously warm SSTs, as well as high confidence on above normal temperatures in NMME. Dynamical and statistical model guidance are consistent over Alaska and favor overall warm probabilities for much of the state. The highest odds of above normal temperatures are in the northeastern part of the state consistent with warm decadal temperature trends . EC is favored for southern Alaska given recent cool SST anomalies off the southern coast.

Enhanced probability of above normal temperature persists through July-August-September (JAS) 2022 through October-November-December (OND) 2022 across much of the CONUS based on statistical and dynamical model guidance. Wet soil moisture led to damped above normal probabilities in parts of the Great Lakes and Ohio Valley in JJA 2022 (33 to 40 percent), but the region is expected to warm slightly from JJA 2022 to JAS 2022 (40 to 50 percent chance of above normal temperatures) based on consistency in dynamical and statistical model guidance. Probability of above normal temperatures decreases to 33 to 40 percent in August-September-October (ASO) 2022 in the Middle Mississippi, Ohio, and Tennessee Valley regions as decadal trends  shift to neutral and dynamical models depict decreased odds of above normal temperatures. Dynamical models also depict decreased odds of above normal temperatures in the Central Great Basin and Southwest (40 to 50 percent) in JAS 2022 through OND 2022 relative to JJA 2022. Dynamical models  and decadal trends  favor elevated odds of above normal temperatures in northern Alaska through OND 2022.

Statistical guidance from the global SST based Constructed Analog (CA), decadal trends, ENSO composites, and skill-based statistical consolidation were the primary tools considered from November-December-January (NDJ) 2022-2023 through JJA 2023. Elevated odds of above normal temperatures remain for much of the CONUS in NDJ 2022-2023, with the highest probabilities in the western US through the Southwest and along the Eastern Seaboard (40 to 50 percent), though probabilities have been reduced given the absence of dynamical model information. Decadal trends , ENSO, and statistical tools continue to favor above normal temperatures in the western US and along the Eastern Seaboard through JJA 2023. Trend and potential for La Niña teleconnections led to a slight tilt toward below normal probabilities in the Pacific Northwest and Northern Plains in February-March-April (FMA) 2023 through April-May-June (AMJ) 2023. Finally, ENSO, trend, and statistical consolidation tools generally favor above normal temperatures for much of Alaska through JJA 2023, and below normal temperatures over the Alaska panhandle.

PRECIPITATION

The JJA 2022 precipitation outlook favors below normal seasonal precipitation amounts for the region stretching from the Northwestern U.S. across the Central Plains and Southern High Plains given low soil moisture anomalies and consistency among dynamical and statistical models that favor probabilities of below normal precipitation over the region. Over the Southwest, slightly elevated odds of above normal precipitation are favored given the dry pattern over the Plains, which is anti-correlated with the precipitation pattern over the Southwest and can be associated with potential for an early Monsoon. Given recent high soil moisture anomalies in parts of the Northern Plains and Upper Mississippi Valley, EC is favored in the region. Above normal precipitation is favored along the Eastern Seaboard consistent with dynamical model guidance from NMME and C3S as well as statistical tools. Dynamical model guidance from NMME, C3S, and CFS along with decadal trends  support enhanced odds of above normal precipitation over the North Slope, Interior Basin, and South Coast of Alaska.

Throughout the summer and into late fall 2022, below normal precipitation is favored to persist across much of the Plains and interior Northwest. A slight tilt toward above normal precipitation is maintained through JAS 2022 in the Southwest as we expect an enhanced monsoon season given the anti-correlated precipitation pattern. Slightly elevated chance of above normal precipitation remains along the Eastern Seaboard through ASO 2022 consistent with ENSO and trend tools, which diminishes in size consistent with trend in SON 2022 through OND 2022. Above normal precipitation trends  dominate the forecast for the Ohio River Valley while below normal precipitation trends  dominate the forecast for the Southwest in early 2023. April-May-June (AMJ) 2023 through JJA 2023 forecasts depict elevated odds of above normal precipitation in the Southeast owing mainly to ENSO and decadal trends . Trends  support a slight tilt toward above normal precipitation over Northern Alaska through FMA 2023. A slight tilt toward below normal is favored in dynamical models  over the Alaska panhandle in September-October-November (SON) 2022, which persists through AMJ 2023 supported by trends .

Week 3-4 Analysis