Written by Sig Silber

Updated at 10:40 AM EDT June 18, 2021 to Include the just received JAMSTEC Forecast. Updated at 4:20 PM EDT June 18, 2021 to incorporate the Week 3/4 forecast to improve the visual consistency validation of the forecast.

Here is the June 17, 2021, NOAA four-season forecast for CONUS and Alaska including the Early Outlook for July, 2021. It covers a period that begins one month later than the forecast last month and extends one month longer. Also included is the updated three-month drought forecast. The main changes seem to be a better North American Monsoon this summer as compared to the forecast last month but much drier conditions than forecast last month from OND this year through MAM 2022 in all or part of the Southern Tier. This second change is very bad news. In two or three days we hope to publish the comparison with the JAMSTEC forecast.

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The bad news from the NOAA Discussion.

See the Appendix for how to enter this fun contest. There is no quarantee but it is entirely possible that the information in this article will help those who enter the contest win a home weather station. Participating in the contest is a very good way to learn about the Southwest Monsoon also called the North American Monsoon and perhaps most correctly the Sonoran Monsoon.

A. Focus on the NOAA Update

A note about terminology; the deviations from climatology/normal are color-coded but also labeled “A” for more than (above) normal and “B” for less than (below) normal. The area designated EC means Equal Chances of being more or less than normal. In my comments for the shorter-term maps, NOAA uses “N” instead of “EC” as they believe they can be more definitive for shorter time frames. So the words “warm”, “cool”, “wet”, “dry” should be generally interpreted as being relative to climatology/normal for that location and time of year.

First, we will take a look at the NOAA Early Outlook for July 2021. It is called the Early Outlook because it will be updated at the end of June. Only the July Outlook will be updated at that time.

Temperature

Precipitation

We have nothing to compare these maps with as NOAA does not provide in their Update a forecast for each of the subsequent two months separate from their three-month forecast. Thus I do not have forecast maps for July from the previous NOAA Report to compare against. The current month is not over so we can not really compare the forecast for next month against the actual for this month. If we do the comparison with JAMSTEC, we have been receiving monthly forecasts for the first three months so we may be comparing the NOAA and JAMSTEC forecasts for July but I have not yet received the forecast from JAMSTEC so I do not know if I will. We will see. It is probably best in this article to just try to understand what NOAA is trying to convey about July*. For Temperature, Southern Alaska is warm. Most of CONUS is warm but there is a very large EC area. The highest probabilities for being warmer than normal are in Nevada and Utah and in part of New England.

With respect to precipitation, Alaska is mostly wet with NE Alaska EC and the Panhandle dry. That dry anomaly continues it seems into the Northwest exteding into North and South Dakota. There is a large Southeast wet anomaly but the southern part of Florida is EC. Listen up all those planning to play the Monsoon Fantasy Game describe at the end of this article. NOAA is forecasting a normal North American Monsoon in July. You might want to pay attention to the three-month forecast.

* compared to normal/climatology for the indicated time of the year.

Visual Consistency Testing.

It is useful to see how the month forecast fits with the set of shorter forecasts that we have. The first two maps cover only June and the third map as of today covers through July 9. Thus only the third of the three maps is at all useful for this purpose. The Seasonal Outlook was issued early this month since the third Thursday fell on June 17. The earliest possible issue of the forecast is on the 15th of the month. We are publishing on a Thursday so we do not have the updated Week 3-4 forecast. 9 days is not an adequate basis for doing this visual consistency testing but it is worth looking at. There are 31 days in July. We have now updated this article and we now have 16 days which is marginally adequate for our purposes.

First Temperature

The new monthly forecast is to the right. Does it appear to be reflective of the parts of the month for which we have forecasts?		We have updated this section since the Week 3 – 4 forecast has been issued this Friday, June 18, 2021 We will revisit the forecast at the end of June when the July forecast is updated. It does not look like South Florida will work out as shown in the Monthly forecast if the Week 3/4 forecast proves to be accurate.

And then Precipitation

The new monthly forecast is to the right. Does it appear to be reflective of the parts of the month for which we have forecasts?		We have updated this section since the Week 3 – 4 forecast was issued this Friday, June 18, 2021 We will also revisit the forecast at the end of June when the July forecast is updated. The month forecast looks pretty good but the wet area may be shown as too far east but we will see how it works out.

Sometimes it is useful to look at the Week 3-4 Discussion. We have now added it when it was issued on Friday June 18, 2021.

Week 3-4 Forecast Discussion Valid Sat Jul 03 2021-Fri Jul 16 2021

ENSO-neutral conditions remain across the tropical Pacific. As indicated by RMM indices, weak convection associated with the Madden Julian Oscillation (MJO) is observed over the Indian Ocean. Dynamical model guidance suggests that the MJO will become inactive in the coming days. There is potential for weak convection to re-emerge over the Western Hemisphere during Week-2, but model uncertainty exists with regard to the amplitude of the signal. Furthermore, tropical impacts on North American sensible weather during the summer months are often weak. Today’s Week 3-4 temperature and precipitation forecasts rely on dynamical model guidance with considerations from long-term trends and soil moisture conditions.

There is reasonable agreement among forecast guidance in terms of the predicted large-scale 500-hPa circulation patterns. The dynamical models (CFS, GEFS, ECWMF, JMA, and the SubX multi-model ensemble) consistently forecast ridging over the Aleutian Islands and over the Northern Rockies and Plains, although the JMA solution is weaker in amplitude relative to the ECWMF and the CFS. Larger discrepancies are also noted over the Gulf of Alaska where solutions range from weakly negative 500-hPa height anomalies (GEFS) to positive height anomalies (CFS).

The temperature forecast for the Week 3-4 period tilts toward above normal probabilities for much of the northern tier of CONUS, consistent with the predicted ridging over the region and decadal trends. The highest probabilities are forecast over the Intermountain West where model agreement is strongest. Below normal temperature probabilities along the Gulf Coast are favored by dynamical model guidance and are further supported by the high soil moisture in that region. Over Alaska, equal chances are forecast for much of the state due to conflicting signals across the model guidance, but above normal temperature probabilities are consistently favored for the Aleutian Islands and the North Slope.

The precipitation forecast also reflects the aforementioned ridging over the Northern Plains and decadal trends resulting in enhanced probabilities for dry conditions over the Pacific Northwest extending into the Plains. Elevated probabilities for above normal precipitation are forecast along the Gulf Coast from Alabama to Texas. Some models (particularly the GEFS) indicated the potential for moisture into the Southwest related to tropical cyclone activity during the Week 2-3 period, but track/intensity are highly uncertain at these time scales and thus equal chances are forecast. Equal chances are also favored for the East Coast as well as Alaska due to high model uncertainty.

Near-normal sea surface temperatures dominate the region surrounding Hawaii. Dynamical model guidance from the SubX suite indicates equal chances with a slight tilt toward above normal temperature probabilities in the northwest islands. Similarly, dynamical models favor equal chances in the southeast, increasing to slightly above normal probabilities in the northwest.

Now we consider the three-month Outlook.

Notice that the three-month periods are abbreviated e.g July/August/September is shown as JAS. You will see such abbreviations often in this report.

Prior Temperature Outlook for JAS 2021

New Temperature Outlook for JAS 2021

Now Precipitation.

Prior forecast for JAS 2021

New Precipitation Outlook for JAS 2021

I can make the comparison easier by showing the prior forecast and the current forecast side by side.

	Prior Forecast	New Forecast
Temperature
Precipitation

Now let us focus on the long-term situation.

First Temperature

Prior 14 Month Temperature Outlook: JAS 2021 – JJA 2022

New 14 Month Temperature Outlook: ASO 2021 – JAS 2022

To compare maps from one release to another, one needs to remember that the new release drops one three-month period and adds a later one. So to make the comparisons one has to shift the new maps to the right one position and that makes the map on the right drop-down to become the left-most map in the next level. I do not have a computer software tool for doing that for you so you have to do it mentally. When I do the comparison, I print the two sets of maps and put them side by side and number the same three-month maps 1, 2, 3,…..,11 in both sets of maps to make it easier for me to easily compare the same three-month period in the new with the previous forecast.

I am now showing them side by side in addition to one after another. It is easier to make the comparison this way but to do it I have to make the maps smaller and readers have to remember how to compare two sets of maps when one starts a month later than the other. Here goes:

Forecast Issued Last Month	Forecast Issued This Month

Based on this procedure, I conclude that:

Now Precipitation

Prior 14 Month Precipitation Outlook: JAS 2021 – JJA 2022

New 14 Month Precipitation Outlook: ASO 2021 – JAS 2022

I am also going to show the two graphics side by side. It is tricky because the array for the current month starts one month later. So you have to follow the instructions I provided with the temperature array of maps. So you can compare the forecast maps by looking at the large ones which are shown with the prior month forecast followed by the forecast this month or you can look at them side by side.

Last Month	This Month

If you want larger versions of each newly issued map (temperature and precipitation) you can find them here. And then each of those maps can be clicked on to further enlarge them.

Sometimes it is useful to compare the three-month outlook to the forecast for the first of the three months. It shows how much the pattern changes over the three months.

One can mentally subtract the First-Month Outlook from the Three-month Outlook and create the Outlook for the last two months in the three months.

*The concept is that the probabilities of a deviation from climatology in the First Month and the combined Month Two-Three forecast that one derives must average out to the probabilities shown in the three-month maps.

Below is the NOAA Discussion (slightly reorganized) released by NOAA on June 17, 2021. Headings that are “Initial Cap” only rather than all caps were added by the Author of this Update Report for clarity. Also, we have organized the sequence of the sections of NOAA Discussion to first present the Atmospheric and Oceanic Conditions and then the Initial Month (July), the NOAA Summary for JAS, and finally the remainder of the 15-Month Forecast.

CURRENT ATMOSPHERIC AND OCEANIC CONDITIONS

The coupled oceanic and atmospheric observations reflect ENSO-neutral conditions. During the past four weeks, sea surface temperatures (SSTs) returned to near average across most of the equatorial Pacific Ocean. In the last two months, positive subsurface temperature anomalies extended across most of the Pacific Ocean. However, recently, negative anomalies have emerged in the Central Pacific at 50-200m depth. Beginning in mid-March, integrated upper-ocean heat anomalies have been positive. Since early May, these positive anomalies have weakened to near zero. During the past 30 days, suppressed convection was located south of the Equator near the Date Line and over parts of Indonesia. Enhanced convection was evident over the far western Pacific Ocean. The RMM index recently emerged over Africa with enhanced convection noted over the tropical Atlantic. A weakening of this signal is anticipated and models are predicting a potential new intraseasonal feature over the Western Hemisphere by late June.

PROGNOSTIC DISCUSSION OF SST FORECASTS

A majority of the models in the IRI/CPC plume predict ENSO-neutral to continue through the fall 2021. By the late fall and winter, La Nina chances increase to near 50 percent, reflecting the historical tendency for a second winter of La Nina following the first, and also the predictions from the North American Multi-Model Ensemble. However, these cooler conditions are predicted to exist for a short duration (3 overlapping seasons) and these predictions are still over 6 months into the future. In summary, ENSO-neutral is favored through the Northern Hemisphere summer (greater than 60 percent chance for the JAS season) and fall (50 percent chance for the SON season). El Nino is the least likely scenario (less than 10 percent chance) through the upcoming winter.

30-DAY OUTLOOK DISCUSSION FOR JULY 2021

The July 2021 outlook was prepared based on dynamical model and statistical forecast guidance, current soil moisture/drought conditions, potential impacts from the MJO, and newly derived long term trends from the 1991-2020 base period.

ENSO neutral is likely to continue through the outlooks period. The MJO may also influence the climate pattern. Model predictions for MJO indicate a strengthening over Africa and the western Indian Ocean, though there is another area of upper-level divergence over the Western Pacific. If the signal emerges, it would increase the variability throughout the month. That potential resulted in some lower probabilities for some regions, as explained below. Drought is largely entrenched over the western CONUS and Northern Plains, and the summer months are prime months when current soil moisture values can impact temperature and precipitation in following months.

Temperature

Above normal temperatures are favored along the Rockies and across the West, with the highest odds in the Great Basin and Four Corners region. The deeply entrenched drought, long-term trends , and numerical guidance (dynamical models and statistical tools) all indicate above normal temperatures are most likely. For the Pacific Northwest and Northern Rockies, an active MJO could result in more variable conditions, so the odds are more modest in those regions. Sea surface temperatures are also likely to be below normal near the California coast, moderating odds there as well. Equal chances for above, near, and below normal are indicated across the Southern Plains, Middle and Lower Mississippi Valleys, and portions of the Southeast. Temperature trends as indicated in the OCN are not as strong there. The suite of dynamical model guidance from the NMME, C3S, and CFS all indicate a relative relaxation of probabilities for above normal temperatures, while some statistical tools favor below normal temperatures, so the mixed indications from the tools result in EC. For the Great Lakes and Northeast, trends , dynamical model guidance, and statistical tools are all largely in agreement for above normal temperatures. Across Alaska, the signals are a bit more mixed as summer trends are not as strong as winter trends , and some NMME models indicate below normal temperatures. More recent model runs and some statistical tools (SST-CA and ENSO-OCN) support higher odds over southern Mainland and eastern Alaska in the outlook.

Precipitation

Above normal precipitation is indicated from the Gulf Coast to the Ohio Valley, consistent with dynamical model guidance, though the guidance has shown variability in recent runs for the Carolinas and Florida, so odds in those places are low. Statistical tools and dynamical models show a consistent signal for below normal precipitation from the Pacific Northwest to the Northern Plains, though an active MJO could introduce short-term wetness in mid to late July (however this would be very atypical), so below-normal precipitation is still favored, but probabilities are lower along the coast. Some dynamical models indicate wetness into the Four Corners region, but half of the statistical tools (CCA and SST-CA) do not. The precipitation OCN shows a weak wet signal from Central California to Oklahoma in a broad swath, though amounts are low and the pattern is not similar to other tools, so equal chances is indicated in the outlook. NMME, C3S, and statistical tools support above-normal precipitation for western mainland Alaska.

SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS (Focus on July through September)

ENSO-neutral conditions are present across the equatorial Pacific Ocean, as represented in current oceanic and atmospheric observations. The official CPC ENSO forecast indicates that ENSO-neutral conditions are likely to persist through the fall. Looking further ahead, El Nino is the least likely scenario through the upcoming winter.

Temperature

The July-August-September (JAS) 2021 temperature outlook favors above normal temperatures for Alaska, the western half of the CONUS, the eastern quarter of the CONUS, and the Northern Plains, with the largest probabilities (greater than 60 percent) forecast across the Northeast.

Precipitation

The JAS 2021 precipitation outlook depicts enhanced probabilities of below normal precipitation amounts across the Pacific Northwest, Rockies, and parts of the High Plains. Above-normal precipitation is more likely from the Eastern Seaboard to the Lower Mississippi Valley and parts of the Southern Plains. Above normal precipitation amounts are slightly favored for parts of northwestern Alaska. Equal chances (EC) are forecast for areas where probabilities for each category of seasonal mean temperatures and seasonal accumulated precipitation amounts are expected to be similar to climatological probabilities.

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 when they are available, as was the objective, historical skill weighted consolidation, that combines both dynamical and statistical forecast tools.

Additionally, the official ENSO forecast depicts probabilities of El Nino that are significantly less than climatological probabilities through the upcoming winter. This anticipated lack of an El Nino signal played a role in the construction of these outlooks. Anomalously wet (dry) soil moisture conditions was also a factor in the temperature outlook across the Southern Plains and Lower Mississippi Valley (northern Great Plains) during summer and early fall.

At later leads, decadal trends in temperature and precipitation were increasingly relied upon in creating the seasonal outlooks.

PROGNOSTIC DISCUSSION OF OUTLOOKS – JAS 2021 TO JAS 2022

TEMPERATURE

Above normal temperatures are favored throughout a majority of the forecast domain during JAS, except for parts of the Southern and Central Plains and the Lower and Middle Mississippi Valley, where equal chances (EC) of below, near, or above normal temperatures are forecast. This EC area is due to weaker signals among temperature tools coupled with abnormally wet soil moisture conditions across most of this region and represents a reduction in above normal temperature probabilities relative to last month’s outlook. Probabilities of above normal temperatures are increased relative to last month across the Northern Plains due, in part, to continued dry soils. Chances of above normal temperatures are also increased for the Northeast due to excellent agreement among both dynamical and statistical guidance. Above normal temperatures are favored throughout Alaska during JAS, but with a reduction of probabilities across the Panhandle compared to last month where dynamical model support is the weakest.

From ASO through SON, above normal temperatures are favored across the entire CONUS as soil moisture impacts begin to diminish. Thereafter, the forecast pattern increasingly begins to reflect trends with above normal temperatures favored across the southern and eastern CONUS through the fall, winter, and next spring. Probabilities of above normal temperatures peak in the Southeast during the winter, consistent with an anticipated absence of El Nino, and again later next Spring, as trends play a greater role. Conversely, below normal temperatures are slightly favored for the Northern Plains late this upcoming winter into early spring consistent with recent trends and corresponding to a strong cold signal from ENSO composites. Elevated chances of above normal temperatures return to the entire West Coast by late next Spring consistent with trends. Forecast uncertainty is generally high across much of Alaska, where warm trends conflict with colder ENSO composites and dynamical model guidance to varying degrees. EC is forecast across much of southern Alaska from late fall through early spring where disagreements among these conflicting tools are at its greatest. Otherwise above normal temperatures are generally forecast for northern Alaska where the trend signal is the strongest.

PRECIPITATION

Model guidance remains consistent from previous months depicting elevated probabilities of below normal precipitation for the Pacific Northwest, Rockies, and northern to central High Plains during JAS. However, the strength of the signal diminishes considerably farther to the south, resulting in a forecast of EC across much of the Southwest Monsoon Region. Farther to the east, above normal precipitation is favored from the Southern Plains to the Northeast. The highest confidence for above normal precipitation is across the Lower Mississippi Valley, consistent with the strongest signal among dynamical model guidance, and for parts of the Mid-Atlantic States and the Northeast, where statistical tools depict the strongest signal. A small region of elevated probabilities of above normal precipitation is also indicated for parts of northwestern Alaska, consistent with CPC’s skill weighted consolidation tool. EC is indicated for the rest of the forecast domain as signals for the various dynamical and statistical tools are too weak or conflicting to issue a forecast with a sufficient degree of confidence.

As we progress further into late summer and into the fall, dynamical and statistical guidance converge on a drier solution for the Southwest Monsoon Region. This dry signal is consistent with the anticipated absence of El Nino conditions and, consequently, the potential inhibition of tropical activity in the Pacific. Looking further ahead the dry signal expands eastward to encompass the entire Southern Tier from coast to coast by late fall through most of the winter, consistent with absence of El Nino. Thereafter, a region of elevated probabilities of above normal precipitation is indicated for parts of the Mississippi and Ohio valleys late winter into early spring consistent with trends. This region of favored above normal precipitation expands southward to the Southern Plains and eastward to parts of the East Coast during the spring consistent with trends and ENSO composites. Trends also favor dryness for parts of the western CONUS as we progress deeper in the Spring into next summer. As was the case with temperature, uncertainty in the precipitation forecast across much of Alaska is quite high and EC is indicated across much of the state for all forecast leads. However above normal precipitation is favored for parts of the South Coast late in the summer into early fall consistent with ENSO composites and the C3S. Above normal precipitation is also favored for northern Alaska beginning in the fall through early spring due to trends and for eastern Alaska during the winter due to a wet ENSO signal. Trends and ENSO composites also lead to favored wetter than normal conditions for parts of eastern Alaska next summer.

We will discuss this more when we compare the JAMSTEC to the NOAA forecast. But it is useful to look at the JAMSTEC discussion. Just received.

ENSO forecast:
As predicted earlier, observation shows that the tropical Pacific returned to a neutral state. The SINTEX-F predicts that a weak La Nina Modoki-like state will appear in boreal autumn.

Indian Ocean forecast:
Observation shows that the central/eastern tropical Indian Ocean is warmer-than-normal. The SINTEX-F predicts that a negative Indian Ocean Dipole will occur in boreal summer and autumn.

Regional forecast:
On a seasonal scale, the SINTEX-F predicts that most parts of the globe will experience a hotter-than-normal condition in boreal summer (austral winter) except for northern parts of the South American Continent, some parts of India, Indonesia, and northwestern Russia. In boreal autumn (austral spring), the model still predicts most parts of the globe will experience a warmer-than-normal condition, except for Alaska, northern parts of the South American Continent, some parts of Indonesia, India, Indochina, eastern China, Saudi Arabia, and the Middle East.

As regards to the seasonally averaged rainfall in boreal summer (austral winter), a drier-than-normal condition is predicted for central parts of the North American Continent, southern parts of the South American Continent, most parts of the Eurasian Continent, southern part of the Sahara Desert. In contrast, southern Alaska, the western coastal area of Canada, southeastern U.S.A., northern parts of the South American Continent, Philippines, Indonesia, some parts of West Africa, some parts of Central Africa, northern parts of the Eurasian Continent, India, some parts of the Indochina Peninsula, eastern China, and the Korean Peninsula will experience a wetter-than-normal condition.

In boreal autumn (austral spring), a wetter-than-normal condition is predicted for the western coastal area of Canada, most parts of the South American Continent, eastern Australia, eastern parts of southern Africa, northern parts of Europe, northern parts of the Eurasian Continent, India, Philippines, and Indonesia. In contrast, most parts of U.S.A., La Plata Basin, western parts of southern Africa, some parts of West Africa, southern parts of Europe, and eastern China will experience a drier-than-normal condition. Extremely wetter-than-normal conditions in Indonesia will be mostly due to the evolving negative Indian Ocean Dipole.

The model predicts most parts of Japan will experience a hotter-than-normal condition in summer and autumn as a seasonal average. As regards to the seasonally averaged rainfall, Hokkaido will experience a slightly wetter-than-normal condition in summer. Monthly prediction suggests a wetter-than-normal condition in August.

Drought Forecasts

These two forecasts (Monthly and Season) are issued by the same agency but to obtain them you need to access two different links here (for the single month forecast which comes out at the end of the month and here for the forecast issued with the Seasonal Outlook.

Here is the Three-Month Drought Forecast that was issued on June 17, 2021

We can compare the new forecast to the prior forecast recognizing that the new forecast is for a three-month period that begins one month later.

Prior Forecast	New Forecast

There are two versions of the discussion of the seasonal drought outlook: long and short and this month I am providing the long version.

Discussion for the Seasonal Drought Outlook

Tools used in the U.S. Seasonal Drought Outlook (SDO) included the Climate Prediction Center (CPC) temperature and precipitation outlooks for July and July through September 2021 (JAS), various short- and medium-range forecasts and models such as the 7-day quantitative precipitation forecast (QPF) totals from the Weather Prediction Center (WPC), the 6-10 day and 8-14 day CPC extended-range forecasts (ERFs), the Week 3-4 outlooks and related tools from CPC, dynamical models at the monthly and seasonal time scales, the 384-hour total precipitation forecasts from several runs of the GFS, climatology for the JAS season, and initial conditions such as soil moisture. The USDM valid on June 15 was used for initial drought conditions. ENSO-neutral conditions are likely during this outlook period.

Drought remains firmly entrenched across the western CONUS, with nearly 90 percent of the Western Region experiencing drought conditions (D1 or worse) according to the US Drought Monitor valid on 8 June 2021. Recently, the climatological summer ridge shifted to western North America and amplified, resulting in record breaking heat across multiple states and subnormal precipitation for the Northwest. Abnormal heat and dry conditions are favored to continue over the next two weeks based on guidance from the WPC and CPC, and the CPC seasonal outlook favors below-normal precipitation for the Northwest and above-normal temperatures across the entire Western region. The summer dry season in California coupled with below-average snowpack conditions yields little opportunity for drought relief, and the outlooks at all time scales favor drought persistence and expansion across the Northwest. The only region where drought relief is favored is across the southern portions of Arizona and New Mexico, where the CPC seasonal outlook indicates no shift in the climate signal. Monsoon convection typically provides more than 50 percent of the annual rainfall across southern Arizona and New Mexico, so some relief is likely. Due to the spotty nature of the monsoon convection, however, the relief will be localized to some areas, while other areas will experience continued severe to exceptional drought conditions. No drought development is anticipated across Alaska. Across Hawaii, the CPC seasonal outlook indicates enhanced chances for below-normal precipitation. Therefore, continued expansion of drought conditions across the islands is anticipated.

Forecast confidence is moderate to high for the Western Region.

Over the past four weeks, increased wetness improved drought conditions across much of Colorado northward across western Nebraska and South Dakota. Dry weather and warm temperatures resulted in drought expansion across northeastern Nebraska and eastern South Dakota. The JAS period is a wet time of year climatologically for the High Plains, as series of mesoscale convective systems tied to shortwave troughs move over the climatological summer ridge. Precipitation tends to decrease in September. During the next week, the WPC QPF forecast shows generally light accumulations, with the heaviest amounts (0.5 inch) occurring over the far eastern portions of the Dakotas. The Week-2 outlook from CPC shows mixed, low amplitude signals, while the seasonal outlook favors below-median precipitation across parts of the Northern High Plains. Based on the lack of a clear wet signal in the guidance and the long term nature of the drought conditions across the Dakotas, persistence seems to be the most likely outcome. Drought development is possible across southeastern Wyoming, southwestern South Dakota, and northwestern Nebraska based on dry soil conditions and the drier seasonal outlook. The unpredictable nature of high-impact short-term convective events at seasonal time scales reduces outlook confidence in this region.

Forecast confidence is low for the High Plains Region.

Persistent dry weather and periods of above-normal temperatures resulted in drought expansion across parts of the Corn Belt and Great Lakes region. Longer term impacts from drought have begun to set in across the Midwest Region, which makes substantial improvements less likely in the absence of a clear wet signal. Widespread moderate to heavy rainfall (locally exceeding 1.75 inches) is forecast over Iowa, southern Wisconsin, and northern Illinois during the next 7 days, but these amounts are unlikely to substantially dislodge the long term drought conditions. 60-day precipitation departures in the region generally range between 4 and 8 inches. The CPC 8-14 day outlook favors a continuation of above-median rainfall, but probabilities in the core drought area are below 40 percent. The monthly and seasonal outlooks both maintain equal chances for below-, near-, and above-median precipitation. Given the incipient conditions, it is unlikely that climatological precipitation would substantially reduce drought conditions, therefore drought persistence is maintained across the western Corn Belt and Michigan. Since the summer months are a wet time of year and the shorter term outlooks favor wetness, no drought development is indicated. Should a period of hot, dry weather materialize later in the summer, however, flash drought conditions are not out of the question for parts of the central or eastern Corn Belt. Please refer to the monthly drought outlook issued at the end of June for updates.

Forecast confidence is low for the Midwest Region.

In contrast to much of the rest of the CONUS which has experienced dry weather during the past month, parts of the Southern Region, particularly across Texas and the lower Mississippi Delta region experienced copious amounts of rainfall, generating widespread flooding. Small portions of drought remain across far western Texas and central Oklahoma, where rainfall totals were significantly less. In the short to medium term, the National Hurricane Center is monitoring a disturbance over the southern Gulf of Mexico that, regardless of development, is forecast to bring additional heavy rainfall to the central Gulf Coast. Given the wet incipient conditions, short term forecasts showing additional rains, and a wet climatology, no widespread drought development is anticipated in this region. Monsoon convection may help alleviate drought across western Texas, while a lack of a clear wet signal favors persistence of the remaining drought in Oklahoma.

Forecast confidence is moderate to high for the Southern Region.

Subnormal rainfall over the past two months has resulted in pockets of drought in South Florida, parts of the Carolinas and Virginia, northern New England, and eastern Puerto Rico. During the upcoming week, widespread rainfall of 0.75 to 1.5 inches is forecast across the drought areas of New England and the mid-Atlantic, while the summer seabreeze convective regime is anticipated to generate locally higher amounts across southern Florida. Above-median rainfall is slightly favored to continue across the East during Week-2, and both the monthly and seasonal outlooks from CPC favor wetness across the entire Eastern Seaboard. Given these outlooks and the wet climatology, drought removal seems the most likely outcome east of the Appalachians. Summer convection will likely continue to erode drought across Florida and Puerto Rico, and September is the peak of the Atlantic hurricane season. The lowest confidence for drought improvements exists across Maine and far upstate New York, where streamflows are currently very low.

Forecast confidence is high for the Southeast Region, and low to moderate for the Northeast Region.

ENSO Considerations

We have covered some of this when we reported on the IRI/CPC analysis on June 10, 2021. We may discuss it again when we do the NOAA/JAMSTEC Comparison.

Now let us look at the NOAA recent ENSO Update. This happens every month on the second Thursday. I show this because it is the information that NOAA works from in producing the Four-Season Forecast.

ENSO Update [The WOTUS Proposal is at the End of the Article under Environmental News]

The Southern Oscillation Index or SOI being above 7 confirms that the Atmosphere is in tune with the Sea Surface Temperatures in the Pacific along the Equator. At least temporarily the SOI Index is in neutral territory. This is another graphic that we have not frozen.

Below is the graphic above but also one issued five days later. (I believe these images are five-day averages centered on the date shown.)

Prior Version	Updated Version

Here is the BOM (Australia Bureau of Meteorology) Nino3.4 tracker.

Here is their current forecast.

B. Conclusion

From the perspective of NOAA, we are no longer in a La Nina. There is an issue as to how long we remain in that Neutral condition. The tools NOAA uses to forecast the state of ENSO has introduced the concept of a possible double-dip La Nina. That is not unusual. It would be devastating for the West. The change since last month re the prediction for Fall and winter precipitation is by itself pretty devastating news. But the forecast for the North American Monsoon is better but whatever moisture comes via the Monsoon will most impact Arizona and New Mexico and possibly Southern California or Texas but will not have widespread impacts.

Special Appendix

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