Ashen crosses will be placed on the foreheads of many area worshipers tomorrow, Ash Wednesday, which is the first day of Lent.

The ashes, made from last year's Palm Sunday palm fronds, are a reminder of the contrast between flesh and spirit and are often applied with the minister saying, "Remember, O man, that dust you are and to dust you shall return."

It is at the liturgical churches, including all Roman Catholic churches and many Episcopal and Lutheran churches, that services will include the imposition of ashes. Other area Protestant churches will begin teh season tonight with Shrove Tuesday pancake suppers. Some others will hold Special Ash Wednesday communion services, mostly at noon.

Shrove Tuesday is the day before Ash Wednesday. Some groups, like Third Baptist Church at 5th and Q Streets NW, prefer to prepare for Lent before its official arrival. Lent, from the Anglo-Saxon word for spring, is the 40 days (excluding Sundays) preceding Easter.

The Orthodox churches, which calculate Easter from the Gregorian calendar, will begin Lent on March 13.Pure Monday.

Groups with different Christian traditions observe Lent in different ways. Since 1966, the Roman Catholic Church has observed greatly eased rules of mandatory fasting and abstinence from meat, but continues to call upon its followers to fast and avoid meat on Ash Wednesday, Good Friday and all Fridays during Lent.

As Wednesday and Good Friday are considered fast days according to the Episcopal Book of Common Prayer.

During the week, special noon and evening services will be held weekly by many Protestant churches, including study groups on ethical and theological questions. Special musical programs are also Lent features. Some groups take special charitable offerings or do extra work for the poor at this time.

"Operation Rice Bowl," a nationwide campaign by American Catholics to provide money for Catholic Relief Service world hunger and local diocesan food projects, will start four days late this year due to Midwest snowstorms.

Eight million cardboard rice bowls into which Catholic families put money saved from eating an austere meal once or more a week will not arrive in parishes for distribution until Sunday because the Elkhart, Ind. plant which makes them was snowed in.

A program by the presiding Bishop of the Episcopal Church, John M. Allin, of recorded two-minute Lenten messages was so popular last year that its phone bill ate up the budget before Easter.

This year, the message has been expanded to a three-minute toll call to New York paid for by the caller. This year, those calling (212) 867-8065 will have one minute to register their "concerns" on tape, following the two-minute message.

Four Lenten lectures and study groups on the United Church of Christ denomination's recently released "Human Sexuality: A Preliminary Study" will be held at the Westemoreland Congregation Church, One Westmoreland Circle. Dr. Francis E. Ringer, associate professor of theology at Lancaster Theological Seminary, will start the series Feb. 15 at 8 p.m., by speaking on sexuality and its theological perspective.