07/30/2021, 4:16 am EDT
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
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
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, 5:12 am EDT
A major freeze for Southeast Brazil this week! The cold begins Wednesday morning but peaks Thursday morning with widespread -1C to -4C low temperatures. The chill is likely to linger into late week mornings.
07/26/2021, 11:44 am EDT
La Nina development appears to be developing rapidly! The Nino34 SSTA region is already at the La Nina threshold. Last week, the subsurface equatorial East Pacific cooled rapidly and if that trend continues a La Nina onset will be here quickly, possibly by September
07/26/2021, 8:19 am EDT
A stronger-than-normal Bermuda high-pressure system is contributing to the lack of relative humidity in the middle atmosphere across the tropical/subtropical North Atlantic basin. The lack of RH in the mid-level atmosphere is well-correlated to lack of tropical cyclone activity since Elsa earlier this month.
07/19/2021, 9:37 am EDT
Dramatic warming in the Atlantic Ocean in the eastern equatorial region has been dramatic. The warming is not expanding west and northwest as forecast models have forecast, at least not yet.
07/16/2021, 7:58 am EDT
The North Atlantic Warm Hole (NAWH) is an area of persistent cooler-than-normal sea surface temperature anomalies (SSTA) becoming more prominent in 2013 related to increased melting of the Greenland Ice Sheet and persistent each warm season since that time including 2021. The NAWH has been displaced eastward to just-off Western Europe (Fig. 1). Aloft, the air cools over the NAWH and becomes a home for a persistent upper trough. During July, the upper trough has shifted slightly east from the 2021 source region causing excessive rain storms extending from France to Germany to Poland (Fig. 2). Most recently, the rains have caused devastating widespread flooding in Germany.
07/16/2021, 7:51 am EDT
The catalyst to all of the extreme weather in the U.S. during early summer including historic rains in the northwest Gulf States, a strong Southwest Monsoon and anomalous heat over the Northwest has been, in-part a super intense Bermuda high-pressure system (Fig. 1). So far in July, the Bermuda high-pressure system has averaged an astounding 4-6 MB stronger than normal. SLP has routinely been in the 1030 MB range which is unusually high for summertime.
07/15/2021, 11:46 am EDT
Currently, an unusually warm SSTA pattern persists across the central and east Atlantic tropics. The anomalous warm SSTA represents buoyant low-level atmosphere moisture. The IMME (model) forecasts the warm SSTA to surge westward into the northern coast of South America as a La Nina pattern (also) develops by October. The combination of the two SSTA regimes should yield a much-needed wet climate for Brazil.
07/15/2021, 8:25 am EDT
Another upper-level storm shifting east across Europe brought flash flooding to Germany which caused at least 19 deaths according to Reuters New Service. The event shifts to Southeast Europe where additional flooding rainfall is expected the next couple days.
07/14/2021, 1:40 pm EDT
Given the new source region for extreme heat...the D3/D4 drought area across the Canadian Prairies and North-central U.S., anomalous heat can easily shift eastward reaching Minnesota in 10 days.