What We’re Concerned About: U.S. Drought Expansion!

Highlight: What we’re concerned about…

Fig. 1-2: Current U.S. soil moisture anomalies and the deep layer (10-200 CM) soil moisture deficits.

Discussion: Our concern as June closes is the widening dry-to-drought regime across many regions of the U.S. (Fig. 1) COUPLED with a massive zone located in the Central U.S. of deep layer soil moisture deficit (Fig. 2). The deep layer soil moisture deficit is caused by long-term climate. The conditions describe foreshadow expanding drought and attendant anomalous heat for mid-to-late summer. The cooler forecast models of the past week or so should start to turn warmer (and drier).

Today’s 12Z GFS is somewhat warmer in the East for days 6-10 (Fig. 3). The cool-biased GFS now lifts the early summer chill north of the U.S./Canada border while Central U.S. warmth expands eastward (Fig. 4). Similarly, and more dramatically, the 11-15-day forecast also trends much warmer in the East (Fig. 5). By days 11-15, most of the U.S. is warmer than normal (Fig. 6). The GFS may be too warm, but the direction is on target!

Fig. 3-4: The 12Z GFS temperature change from 12 hours ago and sensible forecast for days 6-10.

Fig. 5-6: The 12Z GFS temperature change from 12 hours ago and sensible forecast for days 11-15.

Table 1: The 12Z GFS U.S. population weight CDD forecast compared to 12 and 24 hours ago.