The following content was provided by meteorologist Gail Martell of MartellCropProjections.com:
HRW Rain Chances Increasing
The subtropical jet stream is expected to strengthen late this week bringing a chance for showers to hard red winter wheat. A deep trough of low pressure is expected to develop over the Southwest United States. This would encourage a moist air stream in the Great Plains Saturday, as the Gulf of Mexico opens up.
There may be a sharp cutoff in rainfall across the hard red winter wheat belt, central Kansas having a 50% risk of rainfall, against a 25% chance in the western third of the state. Wheat in western Oklahoma and Texas panhandle may also miss out on rainfall. The High Plains has a semi-arid climate, the western third of the hard red wheat belt. Less than 10% of wheat is irrigated.
Windy Warm Weather on High Plains
The Great Plains forecast calls for strong warming. Tropical air from Mexico would stream up into the Great Plains raising temperatures into the 60s F Wednesday-Thursday, and 10-15 degrees above average. Strong drying would occur on the High Plains with gusty winds and no important rainfall.
Hard red winter wheat worsened January, despite episodes of showers. Oklahoma wheat was reportedly 69% poor-very poor with 75% very short topsoil moisture. Kansas wheat was holding up remarkably well, considering serious drought, the crop reported at 39% poor-very poor, 41% fair and 20% good-excellent.
Midwest Drought Worries Persist
Waves of snow showers on the weekend increased the snow cover in the Upper Midwest. Wildly fluctuating temperatures have led to a freeze-thaw cycle. Very heavy rains that occurred in late January ran off frozen fields in the Upper Midwest, not increasing soil moisture. Growers are worried about dry field conditions, particularly west of the Mississippi River. Drought that began last summer persisted through the fall over a broad area of the central United States. Corn states Nebraska, Iowa, Minnesota, South Dakota and Kansas have not seen much improvement in drought. Nebraska the 3rd top corn state has the worst drought reporting a 8 inch moisture deficit in the long period back to July, 2012. Minnesota and Iowa moisture deficits are 6-7 inches.
Sloppy Wet Forecast in Eastern Midwest
A messy wet forecast is on tap in the southern and Eastern Midwest this week. Not much moisture is anticipated in the northern and western corn belt the next few days, but perhaps on the weekend.
Over .50 inch of moisture is anticipated in the Eastern Midwest, a messy mixture of rain and snow. A swath of heavier moisture above .75 inch is possible in a swath from Missouri into central Illinois. Two bouts of precipitation would occur, the first Wednesday night and Thursday in the eastern Midwest. Daily highs are expected above-freezing, but below freezing at night in Illinois, Indiana and Ohio, leading to sloppy mixture of rain and snow. A second wave of precipitation is predicted Sunday and Monday. The source of all this moisture would be a trough in the subtropical jet stream opening up the Gulf of Mexico encouraging a moist air stream northward, and overrunning frozen Midwest fields. Fluctuating temperatures, with night freezes, suggests significant runoff.
Drought Worries Persist in Argentina and Southern Brazil
Drought concerns continue in Argentina and South Brazil. Despite a rash of showers last week, corn and soybeans did not improve due to persistent hot temperatures and persistent dry field conditions. The last heavy rain occurred more than one month ago.
Hot days and cool nights have been the rule in recent weeks. Recurring high pressure has been very detrimental for crops. The subsiding air associated with high pressure has a drying effect on the atmosphere, lowering the humidity and creating a hostile environment for showers and thunderstorms. Scattered showers have occurred, periodically, but not enough to stem the tide of deterioration.
Argentina crops are most vulnerable to rapid decline, due to delayed planting dates and a shallow root system. A satellite vegetation image for the first half of January showed sub-par vegetation over a widespread area in Argentina's grain belt, worst in Buenos Aires and Cordoba, the top 2 growers of corn and soybeans. Prospects have worsened the past 2 weeks with ongoing dryness.
We are watching a low-pressure system due expected to develop on Thursday morning in southern Argentina that may produce significant rainfall later this week.
Rio Grande do Sul is the worst farm state in Brazil, the nation's 3rd biggest soybean state. Extremely hot temperatures occurred again last week, exceeding 100 F a couple of days in the northwest state. Soil moisture has rapidly declined. Parana crops are relatively better, not experiencing extreme heat, while also receiving relatively heavier rain. Even so, January rainfall was well below average. Parana is the second biggest soybean state, behind Mato Grosso, and Brazil's leading summer corn producer.
While southern Brazil has grown drier, Mato Grosso, the top soybean state, has been hit with heavy rainfall, last week adding up to 100-200 millimeters (4-8 inches).