03/01/2024, 5:00 am EST

A Review: Why the Northeast Pacific Marine Heat Wave/North Atlantic Warm Hole are Important to NA/EU Climate

Executive summary: In Part-1, a review of the influence of the 2014-23 Northeast Pacific marine heat wave (MHW) and North Atlantic warm hole (NAWH) on North America and Europe climate is presented. During this time, the MHW and NAWH patterns have profoundly affected North America and Europe climate. Interestingly, for the first time in 10+ years, the Northeast Pacific MHW is not present. The typical mild NAWH influence on Europe winter climate was pushed southward by presence of a Northwest Eurasia polar vortex during winter 2023-24 resulting in Northwest Africa drought and a record warm southeast North Atlantic basin. In part-2, the MAY-SEP 2024 forecast and influences on North America and Europe climate follow. Fig. 1: The east and southeast North Pacific SSTA analysis reveal no marine heat wave near 145W and warming related to El Nino off the U.S. West Coast. Discussion: For the first time in 10 years, a persistent marine heat wave (MHW) in the Northeast Pacific is not present (Fig. 1). There is some warming off the immediate West Coast most likely related to the 2023-24 El Nino episode. The influence of the cooler Northeast Pacific on winter 2023-24 climate patterns (vs. the previous 10 years) is profound! During the past 10 years, related to the Northeast Pacific warming, on average the winter pattern has featured a high-pressure area in the Northeast Pacific basin and a compensating polar vortex over Canada (Fig. 2). The consistency of the pattern created an optimum climate normal (OCN), a decadal pattern different from a standard 30-year climatology. During winter 2023-24 the opposite regime was present. Low pressure persisted off the California Coast and a compensating ridge formed over Eastern Canada centered on Ontario (Fig. 3). The pattern flip (along with El Nino) is causal for the (mostly) just-finished meteorological winter across North America (and Europe). Fig. 2-3: The prevailing upper air pattern across North America during winter 2013-14 through 2022-23 (left) compared with winter 2023-24 (right). The presence of the Northeast Pacific MHW has profoundly affected summertime climate across North America. The annual 2014-2023 upper air pattern (Fig. 4) identifies the Northeast Pacific ridge and while wintertime has a compensating downstream polar vortex over Canada, the summertime pattern usually features expansion of the Northeast Pacific ridge across the Northwest U.S. and Canada (Fig. 5). The summertime upper air pattern helps to explain the tendency for hotter than normal summer climate of the past 10 years and more recently the long-term drought in Canada causal to the horrific fire season last year. Fig. 4-5: The 2014-2023 annual upper air pattern across the Northeast Pacific and North America and the MAY-SEP pattern for the same 10-year period. While the MHW regime was born in the Northeast Pacific during late 2013, an opposite sea surface temperature anomaly (SSTA) pattern formed in the North Atlantic basin. Since the mid-to-late 1990’s, a multi-decadal ocean climate pattern known as the Atlantic multi-decadal oscillation (AMO) changed to the (warm) positive phase. The warming North Atlantic caused an increased number of annual tropical cyclones and warming of the atmosphere biased toward the northern latitudes. The warmer northern latitudes began to accelerate ice and snow melt in Greenland and Northeast Canada during spring and early summer and the fresh-water runoff into the North Atlantic caused a stratified cool water layer usually south of Greenland surrounded by the warming related to the +AMO regime. Climate scientists coined this “cool pool” as the North Atlantic warm hole (NAWH). Similar with the Northeast Pacific MHW climate pattern, the NAWH has generated an upper air regime most profoundly affecting Europe. During the 2014-2023 OCN, the prevailing upper pattern across the North Atlantic eastward to Western Russia has featured an upper trough near the NAWH and compensating ridge over Europe (Fig. 6) helping to explain the tendency for drought and warmer than normal winter and summer seasons. The influence of MHW and NAWH on climate do not act alone. During the winter of 2023-24 an unusual amount of stratospheric warming caused a polar vortex to become semi-permanent over Northwest Eurasia (Fig. 7). Consequently, the high-pressure center over Europe was pushed slightly southward. The high-pressure area caused most Central and South Europe to observe another warm winter season. However, the southern displacement of the high-pressure area caused drought to develop in Northwest Africa (Fig. 8) and intensification of a MHW pattern off Northwest Africa. The MHW pattern has extended to the North Atlantic tropics leading to the warmest ocean temperature anomalies on record for the main development region (MDR) for North Atlantic hurricanes for this time of year (Fig. 9). Fig. 6-7: The prevailing upper air pattern across the North Atlantic to Western Russia during the past 10 years (left) and just finished meteorological winter 2023-24 (right). Fig. 8-9: Europe Drought Observatory soil moisture anomaly analysis reveals a Northwest Africa drought (left) while a vigorous marine heat wave off the Northwest Africa Coast extends to the tropical North Atlantic yielding a record warm tropical North Atlantic (TNA) index in the main development region (MDR) for North Atlantic hurricanes. In Part-2, what is the Northeast Pacific and North Atlantic SSTA pattern forecast for the 2024 warm season (MAY-SEP)?
01/21/2024, 11:44 am EST

AG Market Climate Reseach: Madden Julian Oscillation Inspires Atmospheric River Storm Track To Develop

What is an atmospheric river? A large and narrow stream of high intensity moisture extending from tropical influences pushed by the jet stream across mid-latitude land masses. The North Pacific atmospheric river is the most famous (and effective). What causes an atmospheric river to form? The best way to create an atmospheric river is the phasing (or connection) between the storm track propelled by the subtropical jet stream and increased heavy convection in the deep tropics enhanced by presence of large areas of strong vertical currents known as the positive (or convection) phase of the Madden Julian oscillation (MJO).
01/05/2024, 9:53 am EST

AG Market Research: If El Nino ends quickly and La Nina emerges after mid-2024, what will rainfall pattern be across warm season in U.S., Europe, Russia, and China?

Highlight: If El Nino ends quickly and La Nina emerges after mid-2024, what will rainfall pattern be across warm season in U.S., Europe, Russia, and China? Executive summary: According to a Reuters report issued October 19, “El Nino to continue into mid-2024, threatening agriculture”. However, ENSO may shift rapidly out of El Nino to neutral ENSO by late Q2/2024 with La Nina to follow somewhere during JUN/JUL/AUG 2024 (Fig. 1). While La Nina is generating, the NCP CFS V2 global SSTA forecast maintains the unusual anomalous warmth of the mid-latitude oceans common during the past 10 years (Fig. 2). Using the ENSO projection of El Nino during Q1/2024 into La Nina by Q3/2024 coupled with an optimum climate normal (OCN) representative of the mid-latitude ocean warming of the past 10 years, a preliminary climate forecast for the 2024 warm season across the U.S., Europe, Russia, and China is generated. Fig. 1: The NCEP CFS V2 Nino34 SSTA forecast identifying the 8 most recent forecast members and the consensus of all models. Fig. 2: The NCEP CFS V2 global SSTA forecast for May 2024 identifies developing La Nina and the dominant warmth of mid-latitude oceans. Forecast discussion: A constructed analog (CA) is used to produce temperature and precipitation forecasts for MAY/JUN/JUL and JUL/AUG/SEP 2024 for the U.S., Europe, Russia, and China. The CA forecast is based on decelerating El Nino to La Nina conditions as identified by the operational Nino index (ONI) coupled with the 2014-2023 OCN climate. United States: Entering 2024, dry soil conditions are present across the East-central U.S. including the U.S. Corn Belt and soybean growing areas. The drought condition has continued to prolong low water levels on the Mississippi River. The El Nino-biased climate is likely to maintain dryness in the Midwest while the South-central U.S. trends wetter. However, once the ENSO transition has reversed toward La Nina a pattern change is expected. Wet climate develops during MAY/JUN/JUL 2024 in the Midwest States while the Gulf Coast (and vicinity) reverses from a wet to dry climate. During MAY/JUN/JUL 2024, most of the U.S. (except California) is warmer than normal. The JUL/AUG/SEP 2024 outlook maintains wet climate in the Midwest U.S. while most of the U.S. is hotter than normal except for the West Coast. Bottom line? The Midwest U.S. (and vicinity) shifts into a wet climate for the 2024 warm season largely related to the shifting ENSO regime. Fig. 3-4: Climate Impact Company constructed analog temperature and precipitation anomaly forecast for the U.S. valid MAY/JUN/JUL 2024. Fig. 5-6: Climate Impact Company constructed analog temperature and precipitation anomaly forecast for the U.S. valid JUL/AUG/SEP 2024. Europe/Russia: During late 2023, a wet pattern erased Europe and Western Russia drought. Only Southern France and Italy have a drought condition. As ENSO shifts toward La Nina as midyear approaches, coupled with the anomalous warm North Atlantic, the MAY/JUN/JUL 2024 climate pattern across Europe and Western Russia features 2 regimes. Dryness with very warm temperatures is likely across the Russia spring wheat zone where summer 2024 drought risk develops. Southeast and East Europe are wet suppressing heat risk. During JUL/AUG/SEP 2024 the Russia spring wheat zone shifts into full-blown drought although not far away Northwest Russia is wet. Anomalous heat follows the Russia spring wheat drought. The Black Sea region turns hot and dry mid-to-late summer 2024. Europe avoids drought during summer 2024 except for France where a full-blown drought emerges mid-to-late summer. Bottom line? Drought in 2024 is ahead targeting France and especially the Russia spring wheat zone and the Black Sea region mid-to-late summer. Fig. 7-8: Climate Impact Company constructed analog temperature and precipitation anomaly forecast for Europe/Russia valid MAY/JUN/JUL 2024. Fig. 9-10: Climate Impact Company constructed analog temperature and precipitation anomaly forecast for Europe/Russia valid JUL/AUG/SEP 2024. China: Soil conditions as mid-winter approaches is satisfactory across wheat-growing areas. However, dryness is affecting soils across the far northern and southern corn/soybean areas. As ENSO shifts out of El Nino and toward La Nina during MAY/JUN/JUL 2024, a wet climate is projected across much of China especially wheat-growing zones. During JUL/AUG/SEP 2024, the outlook is hotter than normal although the wet bias in much of the wheat growing areas continues. Bottom line? The early look at 2024 China crop areas does not favor a major drought. Fig. 11-12: Climate Impact Company constructed analog temperature and precipitation anomaly forecast for China/India valid MAY/JUN/JUL 2024. Fig. 13-14: Climate Impact Company constructed analog temperature and precipitation anomaly forecast for China/India valid JUL/AUG/SEP 2024. Summary/conclusions: While drought concern for the northern hemisphere warm season 2024 is certainly warranted, the drought inspiration is likely away from El Nino and more to do with an ENSO transition toward La Nina coupled with the influence on climate of warmer than normal mid-latitude oceans. The outlook indicates drought risk is highest for Russia spring wheat and followed by France and the Black Sea region. The Midwest U.S. and much of China avoids a major drought during the 2024 warm season.
01/03/2024, 12:45 pm EST

AG Market Research: Marine Heatwaves and East Australia Heavy Rains

Charts of the day: Marine heat waves affecting upper air pattern in Australia. Discussion: Emergence of a marine heat wave (MHW) east of Australia extending to the east of New Zealand coupled with another elongated MHW across the central and southeast Indian Ocean are well-correlated to high pressure ridge areas. In-between the ridge areas, a low-pressure area has spawned over the central coast of South Australia. The upper trough combined with the warmer SSTA off the East Coast is causing excessive rainfall in Eastern Australia so far during meteorological summer 2023-24. Week-2 Ahead Forecast valid January 7-13, 2024: More rains East. Discussion: The persistent upper trough causing the excessive rain in the East continues through next week. Hot and dry weather dominates Western Australia. Week-3 Ahead Forecast valid January 14-20, 2024: Widening wet weather zone. Discussion: A large area of tropical/subtropical rains extend from East Australia to New Zealand. Dry and hot weather persists across Western Australia. Week-4 Ahead Forecast valid January 21-27, 2024: Hot/dry West Australia. Discussion: Later in January the wet weather pattern across East Australia eases.