It’s really supposed to rain Sunday in Philly, ending a record six-week dry run

The Democratic and Republican presidential nominees already had made 39 campaign stops in Pennsylvania. The Phillies were a week away from a disappointing postseason, and the Eagles were prepping for what would be a mortifying defeat in Tampa Bay.

And in what at the time appeared to have all the significance of the Flyers exhibition game that day, on Sept. 28 it rained in Philly. Not much, and it was over by noon, and officially 0.11 inches had landed in the official rain gauge at Philadelphia International Airport.

No rain worth measuring has fallen in the six weeks since, but the people who forecast for a living are all but promising the streak will end Sunday.

“We’re pretty darn certain,” said Amanda Lee, meteorologist at the National Weather Service in Mount Holly. The weather service has stopped short of issuing a rain watch, but she noted that the prospect of a quarter- to half-inch of rain has elicited a certain outsize excitement among the meteorologists.

While no measurable rain has fallen at PHL since Sept. 28, it hasn’t rained more than a quarter-inch since Sept. 7.

Assuming they happen, the rains are more or less the prosaic leftovers of a storm system that has heaped 2 and 3 feet of snow on the Rockies, said John Feerick, senior meteorologist with AccuWeather Inc.

But this “won’t be a drought-busting rain by any means,” he said.

For weeks now, the Northeast has been shielded by rain-repelling descending currents of high pressure that has shut off the Gulf of Mexico moisture pipeline. The high will back off enough to allow rains to develop, probably after sunset, he said, and continue into the morning hours.

Then the dry spell looks to resume, as dryness has a way of begetting dryness. “When in drought, forecast drought,” he said.

The forecast rains come after a week in which the United States appeared to embrace an unprecedented unity — at least in terms of dryness. Close to 88% of the contiguous United States was deemed at least “abnormally dry” by the interagency U.S. Drought Monitor on Thursday.

That was record coverage since the Drought Monitor began keeping score in 2000. That map is likely to undergo change next Thursday, given the storm in the West.

The dry conditions have been somewhat ameliorated by the fact that they are occurring at a time when the foliage and the trees are losing their thirst and people are using less water, but the aridity and winds have set off a rash of brushfires.

Still, drought watches are in effect throughout the region, and all of New Jersey, and brushfires have kept firefighters more than busy.