07/28/2022, 7:51 am EDT

Agriculture/Climate Research: What Weather Pattern Makes a Cold Winter in Europe?

Before issuing the Europe winter 2022-23 climate outlook, a review of what makes a cold winter in Europe is reviewed. Wintertime since the turn of the century is examined. Results identify two regimes: A cold period for most of the first 13 winter seasons of this century and generally mild winter seasons during the past 9 years.
07/17/2022, 12:21 pm EDT

Effects on Climate of Warming Reginal SSTA

Highlight: Mid-latitude warming of ocean surface to continue and become dramatic mid-to-late summer across northern hemisphere supporting increased drought/hot risk. Executive Summary: As northern hemisphere mid-summer approaches, mid-latitude ocean waters are warming to much above normal levels off the East Asia Coast, north and northeast of Hawaii and east of the Northeast U.S. plus the Mediterranean Sea. ECMWF projects the warming to continue and intensify. Large areas of very warm sea surface temperature anomalies (SSTA) are well-correlated with stronger-than-normal high-pressure aloft which increases risk of drought and anomalous heat in the affected areas. We’ve already seen the influence of regionally warm SSTA surrounding Europe promoting high-pressure and the ongoing heatwave. Expect subtropical/mid-latitude high-pressure ridging to increase and strengthen causing developing drought to worsen in parts of East Asia to Japan and much of the U.S. plus Europe to the Black Sea region during mid-to-late summer. Conversely, negative Indian Ocean Dipole (-IOD) will drive a wet climate across Australia. Fig. 1: Current global SSTA anomalies and regions of anomalous warmth. Discussion: Typical of the past 10 years, mid-latitude SSTA pattern during mid-to-late summer becomes historically warmer-than-normal. Currently, waters off the East Asia coast may be approaching the warmest on record (Fig. 1). The North/Northeast Pacific “warm blob” has recently expanded eastward reaching the U.S. West Coast in recent days. The cool waters south-southeast of Greenland are blocking northeastward progress of the Gulf Stream causing oiling of warm waters off the Northeast U.S. coast to south and east of Nova Scotia. Super warm waters off the West and North Coast of Europe and especially the Mediterranean Sea are well-correlated to the Europe heat wave. Also of interest, recent warming across the deep tropics in the North Atlantic Basin. A rapidly developing negative Indian Ocean Dipole (-IOD) is developing northwest of Australia. Fig. 2: The 30-day global SSTA trend identifies mid-latitude northern hemisphere warming. The 30-day SSTA trend is MUCH WARMER off the East Asia Coast and north of Hawaii to North America West Coast (Fig. 2). Warming off Southeast Canada is also sharp! Stronger than normal high-pressure across these warm SSTA regions is causing faster-than-normal up-welling easterly wind which has cooled waters just north of Hawaii and south and east of Bermuda. The September 2022 global SSTA forecast by ECMWF indicates the mid-latitude warming in the North Pacific will strengthen (Fig. 3). In the equatorial region, La Nina continues while the -IOD pattern becomes quite intense. The North Atlantic is mixed with very warm SSTA off the Northeast U.S. Coast and off Western Europe while the Sargasso Sea is temperate to cooler than normal. Fig. 3: ECMWF global SSTA forecast for September 2022 maintains warmer trend of SSTA in the middle latitudes. Conclusion: Typical of the past 10 years, mid-latitude oceans warm sharply during mid-to-late summer. In 2022, the very warm mid-latitude ocean surface is emerging most dramatically depicted off the East Asia Coast. The Northeast Pacific “warm blob” is displaced westward toward the Dateline during the past year but recently expanded eastward to the North America West Coast. ECMWF indicates the already impressive warming of the North Pacific will continue. Indicated is support for anomalous high-pressure ridging across East Asia (including Japan) increasing the risk of very dry and hot conditions. If the warming off the West Coast of North America continues, risk of hot high pressure on the West Coast mid-to-late summer increases. In the North Atlantic, the SSTA outlook is mixed. Warming off of Southeast Canada and the Northeast U.S. Coast continues and implies emergence of high-pressure ridging in this zone. Anomalous heat and continued dryness is the result. High-pressure evolving in this region also sets-up steering currents for tropical cyclones toward the Gulf of Mexico and Southeast U.S.
06/28/2022, 8:09 am EDT

AG Market Research: Review of PDSI and EDDI as U.S. is drying out!

Fig. 1: Rainfall needed to neutralize negative Palmer Drought Severity index. Discussion: U.S. drought concerns are increasing. The dry month of June combined with a lot of heat has caused Palmer Drought Severity Index (PDSI) to trend drier. Consequently, the rainfall needed to neutralize that dry soil moisture signature has increased DRAMATICALLY in late June (Fig. 1). Off the chart (>15 in.) values appear in the NOAA/CPC analysis in Washington, California, Texas, Georgia and North Carolina. As impressive is the rapidly developing deficits in the Midwest U.S. and most of the East. The Evaporative Drought Demand Index (EDDI) which combines soil moisture deficit and atmospheric available moisture identifies a large area of deficit across the southern 2/3 of the U.S. most dramatic in California and the Southwest U.S. to Texas and the Carolinas (Fig. 2). Indicated are areas susceptible to worsening drought conditions via a flash drought scenario. The 14-day change identifies the Midwest U.S. as rapidly drying (Fig. 3). The overnight GFS identifies the tendency widespread dry soils have on rainfall…unless directly from the tropics, areas of moisture tend to underperform. The overnight GFS identifies the southern states where direct exposure to the tropics/subtropics have wet risk and areas to the north, particularly the U.S. Corn Belt are dry (Fig. 4). The 24-hour forecast change reveals the wetter South/East scenario and drier forecast in the Midwest (Fig. 5). The wetter change near the U.S./Canada border is likely overstated. Bottom line? Significant summer of 2022 U.S. drought concern increasing rapidly! Fig. 2: Latest U.S. Evaporative Drought Demand Index (EDDI) identifying areas “thirsting” for water. ED3/ED4 zones represent areas already in drought and potential for worsening flash drought. Fig. 3: Now that we’re into meteorological summer, the EDDI short-term (14-day) change analysis becomes important. The Midwest U.S. is drying rapidly. Fig. 4-5: Widespread regions of dry (or drying) soils have a tendency to resist synoptic (non-tropical) rainfall. Note that the overnight GFS is wet where tropical moisture is present (southern states) but to the north the forecast is drier.    
06/26/2022, 8:55 am EDT

AG Market Research: Model Verification Indicates Recent Cooler/Wetter U.S. Forecasts Are Overstated

Model Verification Indicates Recent Cooler/Wetter U.S. Forecasts Are Overstated Fig. 1-2: June 2022 (so far) U.S. temperature and precipitation anomalies. Discussion: So far, June 2022 is hotter and drier than normal for most of the U.S. (Fig. 1-2). The one exception is the Northwest U.S. where cool and wet conditions have persisted. Welcome wet weather has eased Florida drought. Elsewhere, especially in the Central U.S., dryness and heat has dominated. The June 2022 climate forecast from Climate Impact Company (CIC) was based on a constructed analog.  CIC-CA forecasts are heavily biased toward mid-latitude SSTA patterns due to their increased influence on climate during the past decade. Of course, ENSO is also a significant factor. Soil moisture observations and trends are also heavily considered. The CIC-CA June 2022 forecast was aware of the South-central U.S./Texas heat and dryness and has the general warmer than normal national pattern which includes suppressed heat risk in the Northwest (Fig. 3). However, the Midwest and East U.S. forecast was too wet (Fig. 4). The drier pattern is attributed to the influence of large areas of soil moisture deficit on the general climate. Consequently, leading into mid-summer drought concerns have expanded (Fig. 5). Fortunately, for some areas, drought concerns may ease as the upper air pattern for the next 15 days changes and the prevailing mid-latitude westerly flow aloft entrains Southwest U.S. monsoon moisture to unload fast-moving thunderstorms across parts of the Central and East U.S. (Fig. 6). The pattern change described has been hinted at, especially by the GFS for nearly 2 weeks. Cooler temperature forecasts have eased back natural gas prices. The GFS continues to indicate a cool forecast for the North-central U.S. toward the Northeast States during the medium-range. One note of caution, the GFS temperature bias during the past 2 weeks has been much too cool in the North-central U.S. for medium-range forecasts, especially in the 11-15-day period (Fig. 7-8). Additionally, the West U.S. forecasts have been too hot! Previously, identified was a CIC-CA forecast for June 2022 too wet across the eastern states. Similarly, the operational models have that same wet bias. The GFS ENS medium-range forecasts are much too wet across the North and East U.S. for the past 30 days (Fig. 9-10). The problem is macro-scale drought and a dry trend is overwhelming the sensible precipitation pattern. So…although forecasts through the first third of July have trended cooler (less hot) and wetter, the forecast bias of operational models indicates these pattern changes are likely overstated. Fig. 3-4: June 2022 (so far) U.S. temperature and precipitation anomalies. Fig. 5-6: U.S. soil moisture percentile rankings for June 24, 2022 and the 15-day upper air forecast for North America by the ECM ENS. Fig. 7-8: GFS temperature anomaly forecast bias the past 2 weeks for the medium-range.   Fig. 9-10: GFS ENS precipitation anomaly forecast bias the past 30 days for the medium-range.