North-central drought and Midwest dry-to-drought update.
Fig. 1-2: Yesterday’s updated U.S. Drought Monitor for the North-central and Midwest U.S. regions.
U.S. spring wheat and west/northwest U.S. Corn Belt drought: D3/D4 drought is present across North Dakota, northwest South Dakota and into southern Canada (Fig. 1). D3/D4 drought conditions during summertime do not erode unless an interaction between the prevailing storm track and tropical moisture (or direct impact from a tropical cyclone) occurs. Interaction with tropical moisture for storms passing the northern Great Plains will have to wait until late summer. As a result, harsh drought continues in this region for the next 8-10 weeks (at least). The northwest and north portion of the U.S. Corn Belt is in mostly D2 drought condition (Fig. 2). Once summer arrives this type of a drought is more likely to intensify until tropical interaction with mid-latitude systems develops late summer/early autumn or the remains of a Gulf tropical cyclone moves across the area. Once again, these potential scenarios are later summer. Consequently, the west/northwest U.S. Corn Belt should expect worsening drought. A wet fetch of subtropical moisture is possible across the south and east Ohio Valley during the summer season. West and northwest U.S. Corn Belt is the primary strengthening drought concern. The intensity of the northern Great Plains is reminiscent of the 2012 drought intensity but not reaching that extreme in the west/northwest Corn Belt.
Latest 15-day precipitation/temperature forecasts: For the reasons stated above, significant rain during June/July across an established strong drought region is difficult to produce. Driest model runs are always preferred especially in the low confidence extended-range forecast. Favored is the ECM ENS output which nicely identifies the June pattern…Wet arc from Texas to the Carolinas and also across Central Canada and dry in-between for the West, North-central, Midwest and Northeast U.S. (Fig. 3). This pattern appears to be locked-in for a while!
Farmers need the rain and very little is in the forecast. However, the problem is twofold. An established large drought region cutoff from any tropical moisture to produce rainfall develops the ability for an atmospheric feedback that warms the air aloft. Consequently, semi-permanent high-pressure develops and continuously produces anomalous heat risk which further aggravates drought and causes flash drought to occur. The North-central U.S. is locked in on an extremely hot weather pattern (Fig. 4) through the middle third of June!
Fig. 3-4: ECM ENS 15-day precipitation and temperature forecast for the U.S.
Europe/Western Russia OK for now: After an arid April, Western Europe crop areas were looking at a potential evolving drought situation with summer approaching. However, May 2021 produced just-the-opposite…a lot of rain (Fig. 5) thwarting any developing drought concerns. The exception is Turkey where harsh drought has developed. The Black Sea region gained wet weather during late spring. The 15-day forecast indicates wet weather will suppress drought risk in Spain and Southeast Europe while Ukraine (and east) is the primary first half of June wet target (Fig. 6). Northern Europe, mostly north of crop areas is dry the next 15 days.
Europe/Western Russia crop areas are OK heading into summertime.
Fig. 5-6: May 2021 rainfall anomalies across Europe and the ECM ENS percent of normal rainfall forecast.