08/16/2022, 5:48 am EDT

U.S. Week 2-4 Outlook: Southern rains suppress heat risk.

Highlight: Southern rains suppress heat risk. Northwest to North-central U.S. dryness and warmth elevates drought concerns. Chart of the day: Weekly U.S. population weight CDD anomaly summer of 2022 observations and 4-week forecast plus a busy 7-day rainfall forecast. Discussion: Nationally, each week of meteorological summer (except June 3-9) has produced above normal cooling demand. The hottest part of summer, mid-to-late July, observed the anomalous highest demand. The 4-week CDD anomaly forecast maintains the streak of above normal cooling demand into early September. Meanwhile, the NOAA/WPC 7-day rainfall forecast indicates several areas of heavy rain potential. Most impressive is the enhancement of the Mexico/Southwest U.S. Monsoon the next several days as remnants of heavy rain area crossing Southern Texas the past several days moves into this zone. Heavy rain/severe thunderstorms in Arkansas shift south and expand a wet pattern across the Gulf States. Another batch of rain for the southern Great Plains next weekend. The Upper Midwest to Midwest is struck by a 2-3-day rain event beginning Thursday. New England rainfall is biased mostly toward Maine. Week-2 Ahead Forecast valid August 22-28, 2022: Rain-cooled South! Discussion: An impressively wet forecast is indicated by ECM ENS for the Southwest U.S., Texas to Mid-south States and into the Northeast Corridor for next week. The forecast trend is wetter Northeast and drier in California. The wet weather causes a sprawling area of suppressed heat risk. The Northwest to northern California is hot and dry while the Northeast is very humid. Week-3 Ahead Forecast valid August 29-September 4, 2022: Likely to stay wet South/dry and hot Northwest into early September. Discussion: If next week is as wet as indicated, a feedback mechanism to the atmosphere of wetter soils across the South may cause an upper trough to linger to keep the southern tier of the U.S. on the wet side continuing to suppress heat risk. The upper trough also has a tendency to deflect any tropical entity westward into Mexico or northeastward out-to-sea. North of the wet regime dryness and anomalous warmth continue as Northwest to North-central U.S. and Canadian Prairie drought concerns increase. Week-4 Ahead Forecast valid September 5-11, 2022: Almost pattern change. Discussion: The Northwest should cool off and warmth shift eastward as the middle third of September arrives. During that time, a robust tropical regime is likely. However, the week-4 forecast maintains one more week of persistence. Notable is the ECM forecast of the wet weather core over the Southwest U.S. shifting into California. Needed rain could cause more problems than benefit with flash flooding and mudslides. A low confidence forecast but critical if correct.