Christmas trees
Field crops
Fruit
Home and yard
Nursery and landscape
Turfgrass
Vegetable
Diagnostic Services
Soil/Plant Nutrient Lab
Enviro-weather
Regional IPM Center
Pesticide safety
Organic: New Ag Network
Invasive species
Sustainable ag & food systems
MSU ANR departments
MSU Extension
Site index
Contacts/permissions
| Landscape Alert newsletter | |||||||
|
|||||||
 |
|||||||
| Vol. 23, No. 7, May 23, 2008 |
|||||||
| In this issue Landscape and nursery Exploring alternatives for disease control on trees and shrubs Floriculture diagnostic updatesTurfgrass The start of summerChristmas trees and forestry Christmas trees and forestry insect update Pest management workshop Gypsy moth spray window updateAround the home Carpenter ants: the other unofficial state insect of Michigan The Oriental beetle: another new state recordOther news New core manuals available Recycle your old plastic garden pots and containers Ecological Restoration Field Day Weather news |
|||||||
| back to top |
|||||||
| Exploring alternatives for disease control on trees and shrubs Keeping an eye out for information on less toxic strategies to control pest problems has increased value now due to public pressure for more safe pesticides to be used in the landscape environment. Recently, I ran across this article in an edition of the Branching Out newsletter from Cornell University. I personally know the author and respect the research she does for the ornamentals industry. I hope you find it to be of value to your business. This article is reprinted with permission from Branching Out, An IPM Newsletter for Trees and Shrubs, Vol 15, No.3 (http://branchingout.cornell.edu/ ) - Tom Dudek, MSUE educator. |
|||||||
| Alternative to what? Alternative products are very much the rage today, as the chemophobic public wants reassurance that their landscape maintenance is not poisoning their living environment. Primarily, this has meant an industry-wide shift away from organophosphate chemistries that have high mammalian toxicity. Organophosphates have been widely used as insecticides for the past few generations. During this same time period, fungicides have been made from chemical classes that are inherently less toxic to humans. However, with some of the older fungicides, the potential for negative effects other than acute toxicity has caused concern. In recent years, certain fungicide materials have been banned under laws in trendsetting places like New York City and California. The New York City Local Law 37, enacted May, 2005, excludes from use on City property any pesticides that EPA lists as Toxicity Category I (Danger label), or as known, probable, likely or possible carcinogens, or that the state of California has classified as developmental toxins. Given the public demand for chemicals without strong potential for negative health or environmental effects, the federal government has recently been favoring the registration of softer materials, and the marketplace is embracing them. This article will cover some of the alternatives to the previously popular fungicides that have now been identified as potentially harmful to people or the environment. Strobilurin fungicides The strobilurin fungicides are a group of newer materials that are quite valuable for their broad-spectrum and effective disease management contributions. They are all at least somewhat systemic, and are thus powerful but relatively at-risk for the development of resistance in pathogens. Fungicide resistance is most likely to develop in powdery mildews, downy mildews and Botrytis. Thus labels specify how many times per season a strobilurin fungicide may be used, and it is important to recognize which fungicides are in this group so that you do not mistakenly rotate from one to another: they all have the same mode of action. Compass (trifloxystrobin) is a strobilurin for which all uses are considered reduced-risk by EPA. It has broad usefulness as an ornamentals fungicide, providing excellent control of many leaf spot diseases including anthracnoses, as well as rusts, downy mildews and powdery mildews. Azoxystrobin and pyraclostrobin, the active ingredients in Heritage and Insignia, respectively, are the other widely-used and similarly-effective strobilurin fungicides. These materials should be used wisely, in order to maintain their usefulness in landscape maintenance for a long time to come.
Phos acids Another category of “safer” systemic materials are the phosphorous acids or phosphonates. The first of these was Aliette, fosetyl-Al, which was introduced decades ago. Now a large number of products including Avalon, Flanker, Phostrol, Alude, Fungi-Phite T&O, and K-Phite have been labeled in New York with the same mode of action as Aliette. These vary in their acidity, and in whether there is aluminum included in the formulation, but they all have similar modes of action. The phos acid materials offer some key uses: downy mildew control on roses, Pythium and Phytophthora management, as well as some suppression against certain bacterial diseases. Aluminum toxicity has been problematic with application of Aliette on some plants, such as azaleas. Precautions given on some of the phos acid labels indicate that they should not be applied to heat-stressed or drought-stressed plants, or within 14-20 days of a copper application. These materials should not be applied if the foliage will not dry promptly. Some of the phos acid products are not safe to tank-mix with spreader-stickers, or with flowable chlorothalonil or mancozeb products, so be careful to read the label of the particular material you are using. The phos acid materials may be used on ornamental and bedding plants in landscape, nursery and greenhouse. The ability of these materials to limit Phytophthora disease is unquestioned—this is their strongest suit. Results on other kinds of diseases will be variable. The leaf spot on English ivy caused by Xanthomonas campestris pv. Hederae is one of the bacterial diseases for which phos acids are labeled. Fire blight suppression is also listed for some ornamentals.
Mefenoxam Mefenoxam, known to us in the product SubdueMAXX, has all of its uses considered “reduced-risk” by EPA. SubdueMAXX is a systemic chemical widely used in the nursery trade as a weapon against Phytophthora and Pythium species during production. This same material may be used in the landscape, as well, primarily to inhibit Phytophthora. This is a long-lasting, effective fungicide when it is used against mefenoxam-sensitive strains of Pythium or Phytophthora—if resistant strains are encountered, use a phos acid fungicide instead. As a resistance management strategy, a long-term fungicide management program should employ both phos acids and mefenoxam in alternation. Bicarbonates Potassium bicarbonate, sold as Armicarb, Milstop and Kaligreen, etc. has been used effectively in powdery mildew control programs for years. Some of the product labels containing potassium bicarbonate allow for use on other diseases as well, and it will take some experimentation to learn which other diseases respond to treatment with this active ingredient. This is a contact action material that generally should be used in alternation with other chemical or biological products for best results. If phytotoxicity develops, usually seen as a marginal leaf scorch, use a lower rate or alternate with another material to increase the interval between applications. Biologicals Biological fungicides tend to have negligible toxicity to humans, and no history of carcinogenic or developmental effects on test animals. Data on the effectiveness of the biologicals in landscape use is often limited, but the labels are helpfully broad, encouraging product use for suppression of many different pathogens. Some of the pathogens named on the label may have been suppressed in laboratory plate tests rather than in field trials; time will tell whether they are also effectively treated for under the less controlled conditions in the outdoor environment. Rather than thinking of biofungicides as cures for diseases, think of them as biological tools for treating plants preventively, decreasing the odds that a pathogen will successfully attack to cause disease. Biological controls are thus used as health insurance, not in response to the appearance of disease symptoms. They are very compatible with overall integrated pest management (IPM) philosophy—but one should not wait for a disease threshold to be reached before deploying a biofungicide. In many instances, the best use of a biological may be occasional treatments in alternation with reduced-risk chemicals. One of the best known of the biologicals for disease control is Rhapsody AS, which contains Bacillus subtilis strain QST 713, a bacterium. This protectant material is even approved by OMRI for use in organic production, as well as for use in a broad range of sites including landscapes and golf courses, plus sod and ornamental production. Using a surfactant to improve coverage is recommended, and the higher labeled rates may be needed under significant disease pressure. Rhapsody may be applied as a spray or as a drench. As a spray, its forté is powdery mildew, but a measurable benefit from Rhapsody has also been seen against some bacterial leaf spots, Cercospora leaf spot, Botrytis blight and downy mildew. Only copper treatments offer similar versatility, with effectiveness against bacteria as well as fungi. As a soil drench, the Rhapsody label offers suppression of Fusarium, Pythium, Phytophthora and Rhizoctonia. Actinovate SP, a biofungicide labeled for production and landscape use, has Streptomyces lydicus WYEC 108, an actinomycete, as its active ingredient. Drenches and foliar sprays may be made in the landscape as new plants are being transplanted, or to established plants. Treatments are of benefit only when made preventively. Actinovate’s original use was for soilborne diseases—the label lists problems caused by Pythium, Rhizoctonia, Phytophthora, Verticillium and Fusarium. Some suppression of powdery mildew, downy mildew, Botrytis, Alternaria, and Sclerotinia is also claimed for foliar applications. Studies on ornamental crops have thus far shown powdery mildew and Botrytis to be measurably reduced by Actinovate treatment. The Actinovate AG label, which relates to agricultural uses, includes a mention of Monilinia control, which suggests that the Actinovate SP may help to keep ornamental cherries free from brown rot. This biocontrol is effective at temperatures above 45ºF. A non-ionic spreader-sticker such as Latron B1956 should be added for the best results. For landscape use, treatment can be at transplant or to established plants. Ornamental bulbs may also be dusted or soaked in a suspension of Actinovate SP prior to planting, or drenched subsequently. The material may also be used for pre-plant treatment of bare-root trees. Using alternatives Whether you are employing strobilurins, phos acids, mefenoxam, bicarbonates or biologicals in your business, use of these materials and others with lower human and environmental risk is forward-thinking and commendable. Stay informed regarding research on the effectiveness of new materials you are not familiar with, and conduct small-scale tests yourself whenever opportunities present themselves. Remember that a test should include a non-treated control—a luxury not always available in the landscapes in which you are striving to maintain ornamental quality. |
|||||||||||||||||||||||||||||||||||
| back to top | |||||||||||||||||||||||||||||||||||
| |
|||||||||||||||||||||||||||||||||||
| Floriculture diagnostic updates |
|||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||
| The start of summer Although the official start of summer is still several weeks away, with the Memorial Day weekend upon us and gas prices at $4, many folks may be spending some time around the home this weekend and that ultimately leads to some strolls around the lawn. The cool weather in May and the scant rainfall have resulted in a rather odd occurrence this year. The twice a week mowing frequency that has often been common during the spring growth flush has largely been absent this year. In some areas of my lawn, I’ve even been able to stretch the mowing frequency to about two weeks, of course I was having trouble finding my little Yorky in the yard at that point, but I did save some money on gas for the mower. Memorial Day fertilization The Memorial Day weekend is a good time to make a fertilizer application prior to the ramp up of summer temperatures. If you haven’t applied a fertilizer yet this spring or maybe applied fertilizer in mid-April and want to sustain the color and quality of your turf throughout the summer, the application of a slow release fertilizer in the next week is advisable. An application of a slow release fertilizer would provide a gradual feeding of the turf over the summer months. There is a diversity of products available including natural organic sources and polymer or sulfur coated urea products. I would avoid using the fast release products, such as urea, because it can result in a rapid flush of growth, and the plant will probably use most of the nitrogen applied in about a couple weeks. Don’t forget to fertilize those newly seeded areas as the young seedlings are just starting, but remember to avoid any fertilizer and herbicide combination products. Wait until that new seeding has been mowed several times before considering any herbicide treatments. As always remember to avoid spreading any fertilizer particles on impervious surfaces, such as driveways or sidewalks. If particles do land on the driveway, make sure to sweep them back into the turf in order to avoid washing the particles into the gutter, which ultimately may lead to a lake or stream. Winter annual weeds say goodbye With the warmer temperatures on the way, you can wave goodbye to many of the winter annuals that have had a really nice roll this spring. Among others, some of the winter annuals that’ll be leaving us until this fall are Sherpherd’s purse, corn speedwell and yellow rocket. Winter annuals complete their lifecycle in the spring after flowering and producing seed. There’s really no reason to apply an herbicide now to control these weeds. The optimal time to treat these weeds is in the fall. If you’re interested in seeing what weeds are flowering in your area of Michigan right now, log on to www.msuturfweeds.net and punch in your zip code. I think I observed my first patch of yellow hawkweed flowering on the way into work this week. Yellow hawkweed looks very similar to dandelion, but usually flowers a little bit after the dandelions are done with their yellow landscape covering display. Yellow hawkweed seems common in country lawns which are often defined by low fertility levels. |
|||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||
| Christmas trees and forestry insect update Eastern spruce gall adelgid The pineapple-shaped, green-to-purple galls are now visible at the bases of new shoots of white, Black Hills or Norway spruce. With small populations, you can clip off and destroy the green galls now before they turn brown and open in late July. If you have an unacceptable amount of damage, your next control window is this fall. Pine needle scale Applying insecticides at the proper time is a key element in controlling pine needle scale. Pine needle scale is most vulnerable to insecticides during the crawler stage. Although crawlers are tiny, they are readily visible on the needles, especially if you use a hand lens or magnifying glass. The ideal time to apply an insecticide spray is after nearly all the pine needle scale eggs have hatched and most crawlers have reached the hyaline stage. At this point, the young crawlers are exposed on the needles and have not yet started to produce the hard, white armor. Spring generation eggs hatch in May or early June at roughly 300 GDD50. Usually, eggs hatch within about a week and most crawlers should be in the hyaline stage by 400 to 500 GDD50 (southern Michigan).
|
|||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||
Pest management workshop Friday, June 13 from 3:00-8:30 PM Pesticide Issues - Mike Bryan, Michigan Department of Agriculture. Insect Identification and Management - Dr. Deb McCullough, Entomology. Insect Identification and Management (continued) - Dr. Deb McCullough, Entomology. Disease Identification and Management - Dr. Dennis Fulbright, Plant Pathology. Hands-on lab - Growers will be able to examine insect and plant samples and discuss identification and management strategies.Participants are welcome to bring their own samples and concerns. For registration materials contact: |
|||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||
| Gypsy moth spray window update The continuing cold weather has resulted in an additional delay of opening of the spray window in the Upper Peninsula portion of Zone 5. The Dimilin spray window open date for the Upper Peninsula counties of Zone 5 is now delayed until after May 31. Spruce, fir and Douglas-fir nursery stock being shipped to destinations outside the gypsy moth regulated area requires a new treatment once the spray window is open. The reason is that gypsy moth hatch is imminent and nursery stock is at risk for infestation by larvae ballooning on their silk. Those who ship nursery stock outside the regulated area should consult with MDA staff for obtaining certification to meet the USDA Gypsy Moth Quarantine. The following chart shows actual and projected open/close dates for application of the two groups of pesticides used for regulatory treatment of gypsy moth in nursery stock and Christmas trees. We are listing the projected dates as guidelines to help you plan your pest management program. Since gypsy moth development will vary by location, you will need to monitor development around your farm. Weather conditions will affect caterpillar development and may effect end date of the spray windows. Growers should watch the Landscape Alert for additional announcements.
|
|||||||||||||||||||||||||||||||||||
| back to top | |||||||||||||||||||||||||||||||||||
| |
|||||||||||||||||||||||||||||||||||
Carpenter ants: the other unofficial state insect of Michigan
|
|||||||||||||||||||||||||||||||||||
| I called him and told him what I had found out. He said no problem and then asked me to pick one. I was honored of course and without hesitation, I named the black carpenter ant, Camponotus pennsylvanicus. After all this time, I remain convinced in wisdom of my decision. Carpenter ants may not be gorgeous, but they are hard working – just like MichigandersThey are highly social animals – just like us. Ants are very advanced; they are at the pinnacle of insect evolution. Based on the number of phone calls I get about them, I have concluded that nearly everybody in this fine state has encountered them. I don’t know if this make them popular, but there is no doubt that many of us share our homes with them. Shouldn’t our state insect be one that we keep so close to us? Forget pretty, cohabitation is a much higher standard. The fact that they are considered a pest should be secondary. Carpenter ants are one of the largest and most common ants in Michigan. Most of the people I talk to about carpenter ants think they eat wood and are serious wood destroying pests. Not true, no house in Michigan has collapsed because of carpenter ants. Unlike termites, they only nest in wood and do not eat it. They will bore into wood, but the wood they chose to bore into is wet and well on its way to becoming rotted. When they nest indoors, they are a symptom of a water problem and water problems in structures are far worse than carpenter ants. One does not have to drive very far out in the county to see old abandoned houses and barns that have caved in because their roofs have rotted away because of water infiltration. When talking about carpenter ants, the first thing I ask people is whether or not they see carpenter ants in their home during the winter months when carpenter ants are not active outside. If they see ants during the winter, it is a very strong indication that a colony of carpenter ants exists inside the building. Finding them indoors during the summer does not necessarily mean they are nesting in your house; they may just be coming in from outside. When they do nest indoors, they prefer an enclosed space that remains wet or damp, more or less, or a permanent basis. Carpenter ants are attracted to excessive moisture conditions around windows, doors, showers, bathtubs, dishwashers, leaky pipes and drains, and under leaky roof shingles or roof vents. They have also been found in dry areas such as hollow-core doors and false beams and in foam insulation. They seem to love foam insulation. My canoe, which I store outside, is home to a colony of carpenter ants. It has foam insulation inside of both ends to keep it from sinking when it’s tipped over in the water. Every time I move it, a steady stream of foam bits sifts out of both ends. Then without fail, a parade of carpenter ants carrying eggs, larvae and pupae comes scrambling out of both ends, no doubt perturbed at me for disturbing them. My canoe is 30-plus years old I doubt that it floats anymore, thanks to my little friends. The presence of winged carpenter ants inside the home during the summer, does not by itself, mean you have a carpenter ant nest in your home. Winged ants are the reproductive forms of the colony and usually issue from the colony in late spring. They drop their wings soon after mating and begin to search for a suitable nesting site. They commonly enter structures, but only rarely do they succeed in finding a nest site and most winged forms die before establishing a nest. However, the presence of winged carpenter ants during the winter months means several things. It means there is a colony nesting in the house, the colony is thriving and has been there for at least two years. The best method of controlling an indoor colony of carpenter ants is to locate the nest and treat it directly with a persistent insecticide registered for indoor use. Finding the nest can be difficult since many of the ant’s favorite nesting sites are inaccessible. Begin looking in the rooms where the greatest numbers are found, and observe where they go or come from. Carpenter ants are nocturnal and are most active at night. Carpenter ants are very tidy housekeepers and quickly remove wood shavings, food debris and dead co-workers from the nest area. In many cases, this nest debris accumulates in basements beneath the nest area, so look for accumulations of coarse sawdust and dead ants along and on top of basement walls and in spider webs. Wood shavings do not always mean carpenter ants. Once a friend of mine asked me to help an old friend of his who thought he had carpenter ants. The man showed me some piles of wood shavings on his basement floor. I looked up and noticed that some new wiring had recently been pulled through holes drilled through the floor joists. The electrician hadn’t swept up. The shavings were from the holes that he had drilled to run the wire through. Oops! To help find the nest, try mixing some grape jelly with one teaspoon of ground up dried pet food and use this as a bait to get them feeding and carrying food back to the nest. Put a teaspoon of the bait on a jar lid or piece of foil and place it near where you see the ants. Hopefully, they will use the bait and lead you to their nest area. Keep in mind that carpenter ants are most active at night, so be prepared to do some late night ant watching. Also, carpenter ants nest located under leaky shingles are not easily detected until the old roof is torn off. Every roof that I have replaced over the years has had carpenter colonies in areas where the roof leaked. Most importantly, be sure to make any repairs, if necessary, to keep the area dry once a carpenter nest has been located and treated. Commercially prepared ant baits are available, but I don’t know how effective they are at controlling carpenter ants. They are probably more effective in the winter when the ant’s favorite foods are not available. One internet supplier of carpenter ant baits is http://www.doyourownpestcontrol.com/carp.htm. Be sure to read and follow all the instructions and safety precautions found on the pesticide label before using any pesticide. |
|||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||
| The Oriental beetle: another new state record Several weeks ago, we received specimens of some white grubs that a nurseryman found in container stock that he recently received from an out-of-state supplier. The grubs’ rastor pattern (hairs on the butt) resembled May/June beetle grubs, but they differed significantly from anything that I had seen before. I tentatively identified them as Oriental beetle grubs and sent them on to Jim Zablotny for confirmation. This past week Jim informed me that the USDA had confirmed them to be Oriental beetles, Exomala orientali (Coleoptera: Scarabaeidae). This bug was found last year in Indiana. It is known to occur in Ohio and throughout the northeastern United States. It is a serious pest of turf and many ornamental plants.
|
|||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||
| New core manuals available Completely rewritten commercial and private certification core manuals are now available from Michigan State University (MSU) Extension. The manual for private pesticide applicators (Extension Bulletin E3007) includes the National Pesticide Applicator Certification Core Manual and the Michigan Private Core Manual Addendum. The commercial manual (Extension Bulletin E3008) consists of the National Pesticide Applicator Certification Core Manual and the Michigan Commercial Core Manual Addendum. Including the National Pesticide Applicator Certification Core Manual facilitates reciprocity between states, making it more likely that state regulatory agencies will recognize the credentials of certified applicators working in other states. The national core manual discusses federal pesticide laws and the Michigan-specific addendums add the state of Michigan pesticide laws and regulations. The private applicator addendum also includes private applicator equipment and calibration information. The new manuals are better organized, illustrated, easier to read and more comprehensive than past editions. They also contain more recent information on regulations and pesticide safety recommendations. These manuals are used to study for the initial and renewal certification exams offered by the Michigan Department of Agriculture. After passing the exams, an individual becomes a certified applicator and can purchase restricted-use pesticides. Applicators must renew their certification every three years by retaking the exams or by attending enough MDA-approved seminars to earn credits toward renewal. Each manual is available for $30 from MSU Bulletin Distribution Center or any county MSU Extension office. To find an office near you, visit www.msue.msu.edu. |
|||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||
| Recycle your old plastic garden pots and containers Join us for a one-time opportunity to recycle your old plastic flower pots, tree and shrub containers, plastic trays and labels. Clean out your garage or garden shed and bring as many old flower pots and plastic trays, even plastic buckets that you can find. When: Saturday, May 31 from 8:00 AM to 2:00 PM Where: Watch for the signs posting the location behind the Plant Biology building off Wilson Avenue (parking lot 46). Michigan State University campus What can be recycled? All pots and containers that have recycle numbers on the bottom as follows: #2 HDPE, # 5 PP, #6 PS. We can also take tray flats, plastic buckets and tags. How to prepare It is not a requirement to wash your items before you bring them, but make sure as much dirt as possible is knocked out of the container. Please check that there are no stones or any other contaminants, since these will eventually be melted down by a local Michigan company. All containers and tags should be sorted before you bring them to campus. Please sort by recycle number and size and nest containers tightly. Please view the website for more details: http://www.hrt.msu.edu/RecyclePlasticPots/Default.htm. This is also the day for the great Horticulture Plant Sale located in the Plant and Soil Science building. That will be around the corner off Bogue Road. Details for the plant sale can be found at: http://www.hrt.msu.edu/outreach.htm. Please encourage all landscape professionals and gardeners to bring their plastic pots to this drive. |
|||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||
| experts from The Nature Conservancy, Michigan Natural Features Inventory, The Stewardship Network, Michigan Department of Natural Resources, Michigan Nature Association and Michigan State University. In the afternoon, participants will choose from fieldtrips to nearby sites with oak savanna, prairie or prairie fen, each managed by different agencies.This one-day event will begin at the MSU MacCready Reserve, located 15 minutes south of Jackson, near Liberty, Michigan. The event is targeted to landowners, educators, conservation agency personnel, natural areas stewards, native ecosystem enthusiasts and master gardeners. Additional information and registration is available at: www.stewardshipnetwork.org/FieldDay Registration deadline is Tuesday, June 25. For more information, contact: Anna Fiedler, Department of Entomology, Michigan State University, fiedlera@msu.edu. |
|||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||
| Weather news A broad ridge of high pressure will move into the Great Lakes region Friday, May 23, resulting in sunny and dry weather for at least the first half of the Memorial Day holiday weekend. As the high pressure moves east of Michigan on Saturday, winds will shift from the northeast around to the southwest and lead to rapid warming trend. High temperatures Saturday will edge back to near normal levels from the low 60's far north to the upper 60's south. Low temperatures Saturday morning will drop back to the mid‑ and upper 30s north to the low 40s and warm to the 40's to low 50's statewide on Sunday morning. Some scattered light frost is possibile Saturday morning in inland, northern sections of the state. By late Sunday, a cool front will approach from the northwest, bringing the chance for showers and thunderstorms beginning in western sections of Upper Michigan Sunday night and then spreading south and eastward into the Lower Peninsula overnight Sunday into Monday (Memorial Day, May 26). This will likely be our best chance for significant precipitation during the next seven days. While area coverage of precipitation is expected to be more than 50 percent, amounts are forecast to generally remain below a half inch. After it passes through Michigan, the cool front is expected to eventually stall out somewhere in the Ohio Valley by the middle of next week with mostly fair and dry weather and near to slightly below normal temperatures expected statewide Tuesday through at least Thursday (highs in the upper 60's to low 70's and lows in the 40's). In the medium‑range forecast period, upper air troughs are forecast across western sections of the United States and across eastern North America. This pattern would support an active frontal boundary somewhere across central and eastern sections of the country with above normal temperatures to the south of the front and near to below normal temperatures to the north. At this point, it appears Michigan and the Great Lake region will remain on the north side of the boundary. National Weather Service 6‑10 day and 8‑14 day outlooks covering May 28‑ June 1and May 30-June 5 both call for below normal mean temperatures and for above normal precipitation totals. Given good agreement among the tools used to create the outlook, forecaster confidence is considered higher than normal. |
|||||||||||||||||||||||||||||||||||
| back to top |
Email the web developer.