It's hard to come indoors from a blizzard without some snowflakes blowing in before you shut the door. So any assessment of the work of the congressional Commission on Immigration Reform should begin with admiration for the job that chairwoman Barbara Jordan did in keeping out most of the "flakes" swirling about in the stormy debate over immigration.

The nine-member commission, the latest bipartisan panel to study this hellishly complex and emotional topic, issued its final set of policy recommendations last week in Washington. The report is 245 pages long, reflecting the detail in which commission members studied immigration. To their credit, they came up with generally reasonable and balanced proposals.

Still, even Jordan--a former member of Congress from Texas largely remembered and justly admired for her measured approach in the Watergate hearings--was affected by the nativist political pressures that have set the negative tone of the immigration debate, especially since last year's vote on Proposition 187 here in California.

Jordan and her fellow commissioners did not buy into the doomsday scenario of extreme restrictionists--that immigration must come to a halt because this country has reached its "carrying capacity." The commission instead concluded that a properly regulated flow of immigrants is in the national interest, bringing in newcomers who help create economic opportunity and enhance American culture, among other benefits. The commission also agreed that the United States should continue its honorable tradition of accepting political refugees.

The commission's recommendations for reordering the priorities under which immigrants are admitted are also level-headed. Priority would go to children and spouses of U.S. citizens and legal residents. Parents would get the next priority. Admission categories for siblings would be eliminated, a practical way to prevent a crush of applications by members of large, extended families. So far, so good.

But the commission stumbled when it decided to recommend lowering the number of legal immigrants admitted each year by about 24%, from the present 725,000 to 550,000, without bothering to explain why in its many pages of documentation.

Neither number is magic, of course. After all, the reason immigration is hard to control is because it responds not to legislated limits but to demographics and economics, the two sciences hardest to predict because they deal with the vagaries of human behavior. That's why the commission should simply have urged Congress to make the number of immigrant visas flexible, to be reviewed and revised annually by the Immigration and Naturalization Service.