07/30/2021, 4:16 am EDT

Brazil Slammed With Historic Snow, Ice and Freeze!

For many folks in Southeast Brazil a first-time experience witnessing snow and ice occurred on Thursday as a historic cold outbreak surged northward across all of the South/southeast Brazil crop areas.
07/29/2021, 2:38 pm EDT

Pacific Decadal Oscillation/Atlantic Multi-decadal Oscillation Outlook

The cool phase of the Pacific decadal oscillation is likely to persist through northern hemisphere winter while the Atlantic multi-decadal oscillation warms for tropical cyclone season before shifting back to neutral phase late in the year.
07/28/2021, 5:51 am EDT

Following The Current And Future Temperature Extremes

Thermal extremes are present and more are ahead! The Central U.S. heat wave marches on and fades later this week into early next week. Another heat wave re-emerges in the West and expands to the North-central U.S. later next week. A North Africa to Western Russia heat wave emerges next week. Meanwhile a freeze strikes Southeast Brazil.
07/27/2021, 12:41 pm EDT

AG Research: -PDO/+AMO Influence Increases Midwest Dry Risk

-PDO/+AMO Influence Increases Midwest Dry Risk While Southwest Wet Monsoon Likely To Reverse Much Drier Fig. 1: ECMWF global SSTA forecast for September 2021 identifies a developing La Nina and related persistent -PDO pattern. The +AMO pattern in the North Atlantic is strengthening. A full-throttle -IOD regime develops northwest of Australia and the South Pacific “warm blob” (cause of the Chilean drought) continues to flourish. Fig. 2: Research has shown a relationship between warm season drought risk across the U.S. and the combination of PDO/AMO regimes. The -PDO/+AMO regime is present now which leads to increased drought risk (red) in the Southwest and Midwest U.S. Discussion: Currently, cool phase of the Pacific decadal oscillation (-PDO) is in-place. Additionally, a marginally warm phase of the Atlantic multi-decadal oscillation (+AMO) is present and likely to gain some strength during late summer. ENSO is currently neutral although La Nina is likely to develop within 1-2 months (Fig. 1). Historically, during the warm season when -PDO and +AMO are established there is increased drought risk to the Southwest U.S. and parts of the Central U.S. (Fig. 2). The well-established -PDO/+AMO regime is anticipated for AUG/SEP/OCT 2021. Consequently, based on PDO/AMO research, the (current) wet Southwest U.S. Monsoon should reverse dry and the tendency for increasing dryness into the Midwest States should increase. Well-established drought in the Far Northwest U.S. should begin to ease especially if La Nina becomes concurrent with -PDO. The diminished drought risk in the Mid-Atlantic States is related to a wet risk for that region enhanced by tropical cyclone activity. Do operational climate forecasts reflect the historical -PDO/+AMO drought risk? The probability forecasts from NOAA (Fig. 3) and IRI (Fig. 4) see the drier change for the Southwest States and carry that dryness into the Great Plains. The CIC forecast also projects a drier Southwest and Midwest climate pattern ahead for late summer to early autumn (Fig. 5). Fig. 3-5: NOAA and IRI probabilistic precipitation forecasts for AUG/SEP/OCT 2021 plus the CIC precipitation anomaly outlook for the same timeframe. Conclusion: Due to the developing -PDO/+AMO regime, risk of drought expansion in the western Great Plains and into the Midwest U.S. increases during AUG/SEP/OCT 2021 (Fig. 6). Already established drought in the West and North-central U.S. strengthens. The exception is the far Northwest U.S. where some wet relief is on the way. Interior Mid-Atlantic drought is also erased by an anticipated wet regime for late summer/early autumn likely related to tropical influences. Fig. 6: NOAA U.S. Drought Monitor and annotated expected changes over the next 1-3 months.