News
04/28/2022, 3:38 pm EDT

Soaking Wet and Cool Great Plains/Midwest U.S. Ahead

Climate forecasts for the warm season indicate expanding drought in the Great Plains. However, short-term forecasts are trending much cooler and wetter especially the next 10 days. ECMWF indicates widespread several to as much as 5-6 in. of rain. Climate signals are not particularly supportive of this event BUT forecast models are definitely trending in the cooler/wetter direction.
04/28/2022, 9:11 am EDT

NOAA U.S. Drought Monitor Updated

The NOAA U.S. Weekly Drought Monitor is updated and based on historical dry soil moisture conditions across the Southwest and West-central U.S. plus sneaky historical wet soils in the Upper Midwest and parts of the Interior Northeast.
04/26/2022, 8:42 am EDT

Update on Evaporative Drought Demand Index

Highlight: Southwest U.S., central/south Great Plains to Texas and Carolinas plus parts of Florida in (flash) drought danger. Executive summary: Of interest is the location of ED3 and especially ED4 level(s) of the Evaporative Drought Demand Index (EDDI) as the warm season is approaching. During summertime these regions are susceptible to worsening or flash drought conditions accelerating serious water shortages, rapidly rising fire risk and if the region is sufficiently large generation of a feedback process to the atmosphere to cause drought to rapidly expand. The regions watched most closely right now are the central and southern Great Plains to Texas, California and the Southwest U.S. and parts of Florida to the Carolinas all susceptible to strengthening ED3/ED4 conditions heading toward June. Discussion: According to NOAA’s Physical Sciences Laboratory, EDDI is a drought monitoring and early warning guidance tool most helpful in identifying high water stress areas most susceptible to both flash drought and ongoing drought. EDDI examines how anomalous the atmospheric demand (“thirst of the atmosphere”) is for a given location across a time period of interest. Of interest is where ED4 (the driest level) conditions are located due to the severe drought implications of that regime. Additionally, Climate Impact Company also identifies EW4 regions where (due to wet soils), flash flood risk increases. EDDI is available daily using a 5-day lag-time. Analysis for one week and 12-week time periods are most common. The current EDDI analysis identifies presence of dangerous ED3/ED4 conditions across south-central Nebraska southward to western Texas, coastal California and the Southwest U.S. Desert, southwest Florida, eastern Kentucky and the eastern Carolinas (Fig. 1). Each of these zones are suffering exceptional drought and are at risk of flash drought or worsening drought during the warm season if sufficient rainfall fails to occur. Specifically, these regions are at risk for critical water shortages, high fire risk and potential feedback to the atmosphere during summertime to cause dry/hot high-pressure ridging to amplify and coincidentally cause drought to intensify. The feedback risk is most likely over larger areas of ED4 conditions as observed in California/Arizona right now. Due to snow melt and above normal precipitation, EW4 conditions have developed along parts of the U.S./Canada border. These locations are susceptible to flash flooding given more snow melt ahead and/or heavy precipitation events. The 90-day EDDI change analysis reveals widespread drying across the western Great Plains, Carolinas and Southwest States into coastal California (Fig. 2). Wetter EDDI trend is notable across Quebec to the Great Lakes region and Washington State. The operational forecasts through 15 days indicate some likely relief to the ED3/ED4 condition in the eastern Great Plains. However, other ED3/ED4 drought regions miss most of the rainfall in the 15-day outlook as indicated by the European Ensemble. In the ECMWF week 3-4 precipitation anomaly forecast, wet weather risk is in the Midwest/Great Lakes region while the ED3/ED4 drought areas are generally drier than normal. With the exception of eastern portions of Nebraska and Kansas, ED3/ED4 drought regions are likely to worsen and expand the next 4 weeks. Fig. 1: Current U.S. Evaporative Drought Demand index (EDDI). Fig. 2: The 90-day EDDI change analysis. Fig. 3: ECM ENS 15-day precipitation anomaly forecast across North America. Fig. 4: ECM week 3-4 precipitation anomaly forecast across North America.
04/26/2022, 8:40 am EDT

Update on Evaporative Drought Demand Index

Highlight: Southwest U.S., central/south Great Plains to Texas and Carolinas plus parts of Florida in (flash) drought danger. Executive summary: Of interest is the location of ED3 and especially ED4 level(s) of the Evaporative Drought Demand Index (EDDI) as the warm season is approaching. During summertime these regions are susceptible to worsening or flash drought conditions accelerating serious water shortages, rapidly rising fire risk and if the region is sufficiently large generation of a feedback process to the atmosphere to cause drought to rapidly expand. The regions watched most closely right now are the central and southern Great Plains to Texas, California and the Southwest U.S. and parts of Florida to the Carolinas all susceptible to strengthening ED3/ED4 conditions heading toward June. Discussion: According to NOAA’s Physical Sciences Laboratory, EDDI is a drought monitoring and early warning guidance tool most helpful in identifying high water stress areas most susceptible to both flash drought and ongoing drought. EDDI examines how anomalous the atmospheric demand (“thirst of the atmosphere”) is for a given location across a time period of interest. Of interest is where ED4 (the driest level) conditions are located due to the severe drought implications of that regime. Additionally, Climate Impact Company also identifies EW4 regions where (due to wet soils), flash flood risk increases. EDDI is available daily using a 5-day lag-time. Analysis for one week and 12-week time periods are most common. The current EDDI analysis identifies presence of dangerous ED3/ED4 conditions across south-central Nebraska southward to western Texas, coastal California and the Southwest U.S. Desert, southwest Florida, eastern Kentucky and the eastern Carolinas (Fig. 1). Each of these zones are suffering exceptional drought and are at risk of flash drought or worsening drought during the warm season if sufficient rainfall fails to occur. Specifically, these regions are at risk for critical water shortages, high fire risk and potential feedback to the atmosphere during summertime to cause dry/hot high-pressure ridging to amplify and coincidentally cause drought to intensify. The feedback risk is most likely over larger areas of ED4 conditions as observed in California/Arizona right now. Due to snow melt and above normal precipitation, EW4 conditions have developed along parts of the U.S./Canada border. These locations are susceptible to flash flooding given more snow melt ahead and/or heavy precipitation events. The 90-day EDDI change analysis reveals widespread drying across the western Great Plains, Carolinas and Southwest States into coastal California (Fig. 2). Wetter EDDI trend is notable across Quebec to the Great Lakes region and Washington State. The operational forecasts through 15 days indicate some likely relief to the ED3/ED4 condition in the eastern Great Plains. However, other ED3/ED4 drought regions miss most of the rainfall in the 15-day outlook as indicated by the European Ensemble. In the ECMWF week 3-4 precipitation anomaly forecast, wet weather risk is in the Midwest/Great Lakes region while the ED3/ED4 drought areas are generally drier than normal. With the exception of eastern portions of Nebraska and Kansas, ED3/ED4 drought regions are likely to worsen and expand the next 4 weeks. Fig. 1: Current U.S. Evaporative Drought Demand index (EDDI). Fig. 2: The 90-day EDDI change analysis. Fig. 3: ECM ENS 15-day precipitation anomaly forecast across North America. Fig. 4: ECM week 3-4 precipitation anomaly forecast across North America.