sure looks nasty. This is from the Purdue U site.

Snow Molds

Two types of snow molds, gray snow mold and pink snow mold, are recognized on turf grass species. They are caused by different pathogens but often occur under the same environmental conditions.

Gray snow mold is first noticeable in early spring, after snow melt is complete. It commonly occurs in areas where snow accumulation is the greatest, e.g. along driveways and in areas where drifts develop. It is caused by a fungus that inhabits most soils. The pathogen becomes active at cold temperatures; only under snow cover when soil is not frozen. Special structures are produced by the fungus to ensure its survival during summer months. Turf affected by gray snow mold has a matted, bleached, gray-white appearance. In most cases, infected grass blades are killed, but crowns and roots usually survive.

Pink snow mold (also called Fusarium patch) also is caused by a pathogen that inhabits midwestern soils. Snow cover is not required for the development of pink snow mold. The pathogen may also be active during cool (40º - 50º F) wet weather in spring and fall. In recent years in Indiana, pink snow mold outbreaks occured as late as mid-June. The fungus is able to survive periods of summer heat and drought as mycelium and dormant spores in the soil. Under favorable conditions, growth of the fungus on grass blades results in a pink cast to affected areas (hence the name pink snow mold). The patches of affected turf become brown or tan as warm dry weather returns. Like gray snow mold, pink snow mold usually kills leaf blades only. However, under especially severe conditions, crowns and roots may be severely damaged or killed.

Management options for midwestern lawns are similar for both gray and pink snow mold. Cultivars of perennial ryegrass, Kentucky bluegrass, and tall fescue that exhibit any resistance to snow mold infection are not available. Also, chemical control is neither practical nor necessary. Serious snow mold problems can be minimized by mowing turf at the recommended heights well into the fall to avoid the exposure of long, lush turf to disease favorable conditions. Eliminating snow piles or accumulations that prolong the duration of snow cover in problem areas will help reduce the snow mold threat. Other practices will help reduce snow mold injury to lawns include improving drainage to eliminate wet pockets within the stand, and lightly raking affected areas in the spring to break up and dry out the matted grass. Reseeding may be necessary if infected areas do not recover by early May.

.... and more from Purdue -

Melting snows revealed some significant snow mold damage. As you know there are two types of snow mold diseases, gray snow mold (aka Typhula blight) and pink snow mold (Microdochium patch). Although they create similar symptoms (circular patches of tan turfÂsometimes with orange/brown margins) the pathogens are not closely related and they have different temperature requirements for infection. Infection by the gray snow mold pathogen occurs within a narrow range of cold temperatures (32 Â 36 degrees Fahrenheit). The insulating effect of snow cover offers extended periods when such temperatures are maintained at the turf surface. Gray snow mold is not common in Indiana, but I have found plenty of it where snow piles have remained all winter. The gray snow mold pathogen produces survival structures called sclerotia that are about the size of a period printed on this page.

Pink snow mold is much more common in the lower Midwest because infection occurs under a wide range of temperatures (32F Â 50F). Symptoms that develop after snow melts, during cold wet weather in spring are attributed to the Microdochium patch phase of the disease. The pathogen produces spores (called conidia) at the edge of circular patches. The conidia may be washed down slope to create new infections, especially on putting greens. Juvenile (less than one year old) creeping bentgrass is unusually susceptible to snow mold damage.

At this time of year, controlling gray snow mold is all about hastening recovery of the patches. Because of the narrow range of temperatures required for infection, the disease will not spread any more this year. Disturbing (raking) the matted turf and perhaps a light application of N will accelerate turf growth as temperatures rise and mitigate the effects of the disease.

We treat pink snow mold differently because it remains a threat through April and May. I do not think fungicides are warranted for fairways, but I would consider an application on tees and putting greens if numerous patches developed over the winter. Turf within the patches are thinned by disease progress and therefore are vulnerable to colonization by Poa annua. It is likely that only a contact fungicide (chlorothalonil) will limit spread while turf remains dormant. Once turf is actively growing, a penetrant fungicide (such as a DMI) may provide more effective control.

Not to worry thisismelissa. I'm here in Masachusetts and I get it every year. Go outside and simply rake all the areas. That is all you need to do. You do not need to apply any type of chemical. Trust me it's unsightly but once you give it a good raking and the sun hits it you'll be OK. My lawn was covered with it this winter. Just last week I raked and Voila,never knew that it was there.

to simplify it all ....

IGNORE IT ... for another few weeks...

first the soil needs to dry out... reducing water.. reduces mold/mildews ...

your next problem is lack of sunshine in the snowwy north .. mildews/molds can not prosper in full sun ... [when is last frost date in z4.. august?? .. lol]

so in a couple weeks.. winter will go away.. the sun will come out ... the soil will dry.. and you will be 90% of the way toward it being gone ...

then go rake thru it.. and get rid of the dead stuff without ripping out the plants .. and see if the lawn is starting to green ...

give it another week or so .... if no sign of life... rake deeper into the soil.. add some PROPER seed ... and plant a lawn that has more resistance ...

its just not something you need to get all wound up about RIGHT NOW ....

now that is all gut .. read all those fine posts above me... and add that to my simple explanation.. and relax.. and see what happens ...

its one of those things that.. IN MY EXPERIENCE.. in the great white north .. is just not that big a deal ... some rotting plant material.. excess water... frozen soil.. and lack of sun.. all get fixed .. MOST OF THE TIME.. all by themselves ...

ken

I believe Melissa may also have been confused by the meaning of "rake" as suggested to her by her local garden center. It seems she's interpreting this as going over the lawn with either a landscaping rake or dethatching rake, while bogey and donald seem to be implying they just used the typical plastic leaf rake to just "fluff" the grass a little to remove any matting and help it dry out. I'm thinking the leaf rake is what was intended, but it may help Melissa if this can be confirmed by those of you who have experienced this before.

I believe I was told to use a metal tine leaf rake to fluff up the grass. However, all I have is a plastic tine leaf rake and it was doing NOTHING. So, I did move to the garden rake. It has done a good job of fluffing the lawn and has only removed minimal blades... and my presumption is that the blades I'm seeing were leftover blade mulch from mowing last fall.... I do not think I've removed any plants attached to roots.

At this point, I've raked the vast majority of the back yard (at least the part where we play). And I made a good dent in the front yard this afternoon and will finish that this evening. The two side yards may be the most challenge as they are very matted down and are, in some places, still quite wet.

We had rain yesterday, but other days have been dry and today was wonderful sunny 60º. So the lawn, for the most part, is dried out and I was able to really see fruit for my labor today as when I was raking, I was able to uncover some new grass trying to pop thru, but was unable to because of the matting.