Dry over the entire Lower 48: Can it happen?

Dear Tom,
Early afternoon on Jan. 21 the national radar picture showed some snow off
of lakes Erie and Ontario, and patchy rain over California, but nothing
elsewhere. Has there ever been a time when the whole nation was dry?
Joseph Morgenstern
Dear Joseph,
Precipitation-free periods might occur across the 48 contiguous states,
though only rarely and briefly.
Retired meteorologist Robert Johns, a 40-year veteran with the Storm
Prediction Center, says, "The most likely period for a few dry hours would
be the fall (probably late September or October) after low-level moisture
has been swept out of the nation and before the cold blasts needed for Great
Lakes snow/rain bands have developed. During this period you would need a
west-to-east weather pattern with the jet stream displaced north into
Canada, possibly with a weak high pressure system over the north and central
Plains."