11/28/2022, 1:13 pm EST

Weekly ENSO Diagnostics: La Nina’s 3rd peak of the 2020-22 cold ENSO episode has occurred.

Discussion: The southern oscillation index (SOI) became choppy in November certainly related to an active transient Madden Julian oscillation (MJO). The presence of MJO implies La Nina may be breaking down. The Nino34 SSTA has warmed slightly the past couple weeks (Fig. 1) and given a projected SOI of +0.45 for November (Fig. 2) diagnostics support slight weakening of La Nina. The projected late 2022 La Nina 3rd peak of the 2020-22 cold ENSO event has likely just-occurred. The monthly SOI dip is the lowest since January of last year. Using SOI to project a constructed analog yields deceleration of La Nina ahead with neutral ENSO by FEB/MAR/APR 2022 followed by a choppy El Nino-like signature later next year through 2024 (Fig. 3). Fig. 1: The 12-week Nino SSTA observations. Fig. 2: Monthly southern oscillation index values adding the projected November 2022 estimate. Fig. 3: Using southern oscillation index, a constructed ENSO phase analog projection through 2024 is indicated.    
11/28/2022, 12:53 pm EST

AG Market Global Weather/Climate ALERT PPTX Presentation

11/28/2022, 9:52 am EST

U.S. 16-20-Day Extended-range Forecast: Turning colder East.

Highlight: Turning colder East (3 days ago below).  Extended-range discussion: Ensembles are trending cooler in the East and warmer across the West-Central U.S. including Canada. The West Coast stays in the face of a (weak) storm track and the Tennessee Valley is wetter than normal.    
11/28/2022, 8:29 am EST

U.S. Month 1-3 Ahead Outlook: Cold North/warm South winter outlook although averaging colder than past 3 winter seasons.

Highlight: Cold North/warm South winter outlook although averaging colder than past 3 winter seasons. U.S. drought concerns remain while MS River low water level an ongoing issue. Executive Summary: The Climate Impact Company month 1-3 ahead climate outlooks for the U.S. valid for meteorological winter are updated. The forecast trend for the winter season based on the updated outlook is colder Northwest and Northeast U.S. and warmer across the South States. The precipitation forecast is not as dry as previously indicated for California and wetter for the Northwest while the Gulf States are likely to observe eastward expansion of drought. La Nina climate dominates the winter season alongside influence of regional SSTA pattern either side of North America. Methodology: Recent constructed analog climate forecasts verified with reduced skill. The most recent example is the warm November 2022 U.S. forecast which will finish much colder than normal in the West and Central U.S. Consequently, Climate Impact Company reverts to the “old” forecast process which includes a consensus between NCEP CGS V2 and ECMWF operational models, La Nina climatology, optimum climate normal and consensus (of previous forecasts). Climate discussion: Although the “old” prediction process returns, the relatively new evolution of the Northeast Pacific marine heat wave and North Atlantic warm hole remain as catalysts to the North America climate during November. The upper-level high-pressure ridge associated with the warm SSTA pattern in the Northeast Pacific shifted west to the Aleutian Islands/Gulf of Alaska during November and was compensated for by an opposing chilly upper trough over the Southwest U.S. Meanwhile, across the North Atlantic cool pool south of Greenland a vigorous upper trough was compensated for by a mild upper ridge over the Northeast U.S. The November forecast projected the Northeast/East upper ridge but not the Southwest U.S. trough. During December, on average, the upper air pattern will shift the upper trough farther northward to the Northwest U.S. toward Central Canada while the Northeast upper ridge elongates and is centered on the Southeast States. The described pattern is typical of a La Nina climate and likely to settle-in through mid-winter with a “polar vortex” style pattern producing increased cold and snow risk possible for the second half of winter. U.S. drought: Precipitation required to end soil moisture deficits is present across much of the U.S. except the Northeast, northern half of the Great Lakes region and Lower Mississippi River Valley. Drought will remain a major issue as the 2023 warm season approaches for all of the U.S. except the Northwest U.S. and Tennessee Valley (and vicinity) Mississippi River water level: Reliable precipitation to reverse the low water level in the central and southern Mississippi River Basin is not forecast through the next several months. The wet bias related to La Nina climate is shifted slightly east of this zone. There is potential for significant precipitation during the breakdown of La Nina climate next spring. U.S. gas population weight HDD forecast: The outlook is generally colder than each of the past 3 winter seasons and certainly colder than the 10-year normal (Fig. 1). The outlook is colder than or near the 30-year normal in November and February. Fig. 1: The Climate Impact Company U.S. population weight HDD forecast compared to the last 3 winter seasons and the 10-year climatology. December 2022: The outlook is heavily biased by the 15-day outlook agreed upon by most operational models featuring cold to very cold weather across the Northwest to North-central U.S. and favoring a warm pattern across the Southern U.S. The second half of December is likely to produce a milder climate in the East while the cold weather remains biased to the Northwest States. The December outlook is very similar to a conventional early winter La Nina climate. The precipitation forecast features two storm tracks: California to the Central Rockies and Tennessee Valley to the northern Mid-Atlantic States. The Western U.S. storm track features mostly snow except the California Coast while temperatures are generally warm enough to produce mostly rain in the East. The forecast trend is colder/stormy in the West while the East is about the same. Fig. 2-3: The Climate Impact Company temperature/precipitation anomaly forecast for December 2022.  January 2023: Well-established snow cover keeps Southern Canada colder than normal for mid-winter and some of that cold air mass occasionally shifts south to affect the U.S. except the mostly warmer than normal regime in the Gulf States. However, at times, Pacific “zonal flow” erodes the cold and can quickly warm the U.S. especially south of snow cover. January is forecast to produce a highly variable thermal pattern with “locked-in” cold likely staying to the north. The storm track shifts northward to the Northwest U.S., typical of mid-winter La Nina climate and also stretches from the Mid-south States to the Mid-Atlantic with the northern fringe featuring mostly snow. New England and New York are colder than normal during mid-winter. The forecast trend is colder West/Northwest and not as cold in the East. Fig. 4-5: The Climate Impact Company temperature/precipitation anomaly forecast for January 2023.  February 2023: All forecast processes continue to yield an increased risk of a “polar vortex” pattern in February. The outlook remains cold across the North-central and Midwest U.S. although not quite as cold in Texas. Cold risk into the Northeast increases. The storm track in the Southeast/East U.S. could be stronger than indicated and if so, feature a snow and ice problem for the Interior East and Northeast U.S. The Northwest U.S. storm track is also vigorous featuring mostly snow. Fig. 6-7: The Climate Impact Company temperature/precipitation anomaly forecast for February 2023.