The northern branch of the jet stream features a trough over Alaska and northwest Canada. A ridge over north-central Canada and a trough over northeast Canada and western Greenland. This is a mild/warm pattern for Canada. The southern branch of the jet features a trough in the Gulf of Alaska. A ridge in the western U.S. A trough over the central U.S. and a ridge over the eastern U.S. The center of subtropical high pressure is over the southeast U.S.EXTENDED OUTLOOK
The U.S. and European models are in good agreement through 7 days. Fair agreement days 8-10. During the 6-10 day period the northern branch of the jet stream will feature a ridge over Alaska and western Canada. A trough over central Canada and a ridge over eastern Canada and southern Greenland. This will be a mild/warm pattern for western Canada, variable central, mild/cool in the east. The southern branch of the jet will feature a trough in the Gulf of Alaska. A ridge over the western U.S. and a trough in the eastern U.S. The trough position will be far enough to the east to limit rainfall in the Midwest. However it will be in a position to cause cooler than normal temperatures.
This pattern will feature near to below normal temperatures in the Midwest. Rainfall near to below normal. The northern plains will see near to below normal temperatures during the next 5 days, variable days 6-10. Rainfall mostly below normal. The southern plains will see near to below normal temperatures during the next 7 days, variable days 8-10. Rainfall near to above normal during the next 5 days, near to below normal days 6-10. The Delta states will see near to below normal temperatures. Rainfall below normal during the next 5 days, near to above normal days 6-10.
Mike PalmerinoNATIONAL TEMPERATURE/RAINFALL EXTREMES:
HIGH MON...113 AT DEATH VALLEY CA
LOW MON...34 AT GOTHIC CO
24 HOUR RAINFALL AT 7PM YESTERDAY...SIOUX FALLS SD 2.15 INCHESUS OUTLOOK AND MODEL DISCUSSION 6-10 DAY PERIOD:
The US and European models are in fair to good agreement during the outlook period, however there are significant differences on timing of features. A couple of significant changes have occurred in both models during the past 24 hours with implications on the US and Canada weather pattern during the 6-10 day period.
The first change involved the tropical wave now in the western Caribbean that was formerly tropical storm Harvey. The models are now in good agreement that this system will regenerate over the southwest Gulf of Mexico after crossing the Yucatan Peninsula today. The most likely track appears to be towards the coastal bend of Texas with a turn towards the north after landfall.
However since there is no organized system as yet the range of possibilities is high. There is some risk for heavy to torrential rains and damaging winds from northeast Mexico through any part of the Texas coast. The European model stalls the system for a couple of days over the middle Texas coast and would thus feature much heavier rains. The models both turn the low towards the Delta and eventually to the Ohio river valley during the 6-10 day period. However, I would caution this is a highly uncertain forecast and subject to significant day to day changes.
The second change involves the northern branch of the jet stream. The models feature a strong polar trough nosing southward towards the Hudson Bay area of Canada. Upper level ridging to the west along with the strong trough leads to a strong north to south flow and the potential for much colder weather to move southward over northern Canada. This is more evident on the US model with the flow originating over the western Arctic circle and bottoming out near southwest Hudson bay. The European model shows more of a northwest to southeast flow starting in northwest Canada and turing east over southern Hudson Bay and James Bay. The models show the coldest weather to be north to northeast of the key growing areas of the Canadian Prairies at day ten. The US model beyond day ten shows the cold weather retreating again during the 11 to 16 day period.
However, it it certainly much closer to areas that we might be concerned with than it was yesterday at this time.
These changes today make for uncertain forecasts both in the short and the long range. I am more confident in the heavy rain/strong wind risk to Texas than I am in either the heavy rain chance for the Delta or the cold weather risk to the southern Manitoba or northern Minnesota area but both of these will still bear watching.
MAJOR WORLD HIGHLIGHTS/IMPACT:
TROPICS: A large area of disturbed weather over the northwestern Caribbean Sea is associated with the remnants of Harvey. Satellite images and surface observations indicate that the system has not become better organized and tropical cyclone development is not expected before the system moves inland over the Yucatan peninsula this morning. However, environmental conditions are expected to be conducive for development when the system moves over the Bay of Campeche tonight or early Wednesday, and a tropical depression is likely to form over the southwestern Gulf of Mexico on Wednesday or Thursday. Regardless of development, locally heavy rainfall and gusty winds are expected to spread westward across Belize and the Yucatan peninsula during the next day or so.
NORTHERN PLAINS (SPRING WHEAT/CORN/SOYBEANS): Mostly favorable conditions for the harvest of a drought reduced spring wheat crop at this time. A few showers later this week in east and south areas may favor filling corn and soybeans but in general a below normal rainfall pattern continues.
CANADIAN PRAIRIES (Canola/Spring Wheat/Durum Wheat): The rain chance over northern Alberta looks somewhat less today than was indicated yesterday.
Showers in this area and then in the eastern growing areas during Friday-Saturday time frame may favor late filling crops but would be unfavorable to maturing crops and to harvesting. As mentioned above, the turn to cold weather in north Canada during the 6-10 day period will bear watching.
MIDWEST (CORN/SOYBEANS): Rainfall last week and during the weekend and early this week will help to improve the condition of filling crops through the western Midwest region, except areas of Nebraska and Minnesota that experienced flooding. Mostly favorable conditions for filling crops in the eastern Midwest, although parts of central Illinois could use more rain.
WEST TEXAS (COTTON): Showers may occur in the region at times during the next 7 days, along with periods of cooler conditions. Cotton may benefit from the added rainfall, especially through southern growing areas, but would probably prefer more sunshine in some sections.
SOUTHEAST TEXAS (COTTON/ENERGY): There is some risk that a tropical storm would form over the southwest Gulf of Mexico and head towards the Texas coast during the next 24-48 hours. This is associated with the remnants of tropical storm Harvey now nearing the Yucatan Peninsula in the Caribbean. This is expected to threaten the oil and gas rigs in the northwest Gulf of Mexico and it is expected to bring heavy rain and winds to cotton areas of the coastal bend.
UKRAINE/RUSSIA (Winter and Spring grains and oilseeds): Above to well above normal temperatures with little rainfall through much of the region during the two weeks but especially through south and east Ukraine and in south Russia.
This has likely increased stress to filling spring grains and oilseeds and is probably impacting yield prospects at this time. Prior weather during the reproductive growth stages was much more favorable in nature. This may limit the amount of damage that could occur to corn. However oilseeds, including soybeans and sunflower, are more susceptible to below normal rainfall and above or well above normal temperatures during August.
NORTHEAST CHINA (SOYBEANS/CORN): Conditions mostly favor reproductive to filling corn and soybeans at this time due to recent generous rainfall.
However, more rain will be needed to support filling crops as seasonal rains remain below normal. The forecast includes some chance for periodic showers and cooler conditions during this week.
INDIAN MONSOON: Key growing areas for cotton, groundnuts and soybeans area in west Madhya Pradesh to Gujarat and northern Maharashtra. The area had been drier and warmer for much of last week. However, late in the week and during the weekend rain returned to the region. Rain, so far, was heaviest in southern areas of west Madhya Pradesh, in Maharashtra and in eastern and southern areas of Gujarat. This rain was especially beneficial to crop areas of Maharashtra.
EXPANDED SUMMARIES FORECASTS:
Midwest corn, soybean and winter wheat
West: Rain, showers and thunderstorms, 0.50-1.50 inches and locally heavier, occurred in extreme east Nebraska, southeast South Dakota, southwest Minnesota, western and southern Iowa during the past 24 hours. Scattered light showers through northeast Iowa during this time. Temperatures averaged near to below normal yesterday.
East: Showers and some rain, 0.25-1.00 inch and locally heavier, through central and southern Illinois during the past 24 hours. Light to locally moderate rain through northern Illinois and northern Indiana during this time.
A few light showers elsewhere in the north and west, drier southeast areas.
Temperatures averaged above normal yesterday, well above normal through southern areas.
West: Mostly dry today and most of Wednesday. Dry or with only a few light showers, favoring northeast and southwest areas, during Wednesday night or early Thursday. Drier again later Thursday. Temperatures average below normal. Highs mostly 74-82F today and Wednesday, 71-81F Thursday.
Light showers with locally heavier favoring north and west areas Friday and Saturday. A few light showers elsewhere in the region during Sunday.
Temperatures average near to below normal south, below normal north, during this period.
East: Light to locally moderate showers favoring southern and eastern areas during today into tonight. Mostly dry or with only isolated light showers tomorrow and during Thursday. Temperatures average near to above normal today, below normal tomorrow and Thursday.
Mostly dry Friday and Saturday. Dry or with only a few light showers with locally heavier during Sunday. Temperatures average below normal Friday and Saturday, near to below normal Sunday.
6 to 10 day outlook...Temperatures are expected to average near to below normal. Rainfall should average near to below normal west, near to above normal south and east.
North Plains (Spring Wheat and Corn)
Summary: Light to moderate showers with locally heavier through south-central to southeast areas during the past 24 hours. Little elsewhere in the region during this time. Temperatures averaged mostly near normal.
Forecast: Mostly dry today. Dry or with only a few very light showers in eastern areas Wednesday and in western areas Thursday. Temperatures average above normal through Montana and the western Dakotas during this period, near to below normal through the eastern Dakotas and northern Minnesota.
Dry or with only a few light showers with locally heavier favoring south and east areas Friday and Saturday. Dry Sunday. Temperatures average above to well above normal west, near to above normal east.
6-10 Day Outlook: Temperatures are expected to average near to mostly above normal. Rainfall near to mostly below normal.
Canadian Prairies (Spring Wheat, Canola)
Alberta, Saskatchewan, Manitoba
Summary: Dry or with only a few light showers in the eastern areas during the past 24 hours. Temperatures averaged near to below normal.
Forecast: Mostly dry or with only a little very light rain or drizzle in eastern areas today or during Wednesday. Chance for sprinkles or light showers with locally heavier through Alberta, western and northern Saskatchewan Thursday or Thursday night. Temperatures average above normal west and below normal east during this period.
Chance for scattered light showers east, drier west, Friday into Saturday.
Mainly dry Sunday. Temperatures turn somewhat cooler in the west and warmer in the east Friday and Saturday, warmer all areas during Sunday.
6-10 Day Outlook: Temperatures are expected to vary somewhat during this period. Rainfall near to below normal. It looks to turn colder through northern Canada during this period. It is uncertain how far south or west to take this colder weather during the outlook period. If the key growing areas of the Prairies were to turn significantly colder it would probably not occur until late in the outlook period.
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