Highlight: High Impact Weather to Develop Europe/Western Russia
Fig. 1-3: The strengthening North Atlantic warm hole (NAWH) upper trough in the latest 15-day forecast, the evolving NAWH SSTA pattern and 30-day SSTA change.
Discussion: The re-intensifying semi-permanent North Atlantic warm hole (NAWH) SSTA pattern in the North Atlantic and the attendant upper trough continues to intensify in the latest 15-day forecast (Fig. 1). The upper trough is located over SSTA which is cooler compared to the surrounding environment (Fig. 2) and the cooler trend is vividly displayed in the 30-day SSTA change chart (Fig. 3).
Initially, the amplifying NAWH trough caused a compensating upper-level ridge over Europe to strengthen to prolong the anomalous warmth of recent months. However, the NAWH trough is extending eastward and will now produce another high impact weather regime across Western Europe…excessive rainfall! The GFS 15-day rainfall forecast indicates several in. of rain with high spots >5 in. for Western and Southern Europe for the second half of November (Fig. 4).
Another residual pattern develops. As the high amplitude ridge shifts north across Scandinavia, a downstream trough develops in Western Russia. In this region, cold weather with snowfall develops in the 6-10-day period and should extend through the 8-14-day period (Fig. 5). Usually, cold weather over snow cover in this region is difficult to remove once established during the early cold season.
Fig. 4-5: The GFS 15-day precipitation forecast across Europe and the ECM ENS 8-14-day temperature anomaly forecast into Western Russia.