TAMPA, Fla. — The U.S. Commerce Department’s inspector general is projecting a 10- to 16-month gap in weather satellite coverage that would limit the National Oceanic and Atmospheric Administration’s ability to forecast three to seven days out.

In written testimony submitted in advance of an April 10 hearing of the Senate Appropriations subcommittee on commerce, justice, science and related agencies, Todd Zinser cited cost overruns, schedule delays and the age of NOAA’s current satellites as likely causes.

NOAA, which is part of the Commerce Department, operates geostationary-orbiting satellites for continental coverage and polar-orbiting craft for global coverage. Budget difficulties and delays to the systems currently under development — the Geostationary Operational Environmental Satellite (GOES)-R  system and Joint Polar Satellite System (JPSS) — have prompted widespread concerns about the coverage gap.

Zinser said that as recently as late March, an internal NOAA report predicted a three-month gap in coverage from polar orbit. He offered a different assessment based on the transition timetable from the existing Suomi NPP satellite, which launched in October 2011, to the JPSS-1.

“We continue to project a potential 10-16-month gap between Suomi NPP’s end of design life and when JPSS-1 satellite data become available for operational use,” Zinser said. He said the 10-month minimum assumes four months between the end of Suomi NPP operations and the JPSS-1 launch, currently scheduled for 2017, and a six-month checkout period following that launch.

“NOAA’s medium-range weather forecasting (3-7 days) could be degraded during the period of time JPSS data are unavailable, but NOAA must do more research using past and current weather events to determine the extent to which forecasts may be affected,” Zinser said.

During the same hearing, Commerce Secretary Penny Pritzker repeatedly said NOAA’s weather satellite programs were “on schedule and on budget.” But she also said, “The potential for a gap is still too high.”

NOAA said that in the case of an early failure of Suomi NPP, the agency would rely on older legacy satellites. But Zinser cautioned against that strategy.

“In the long term those legacy satellites can no longer be expected to function, leaving the JPSS constellation as the sole provider of key data from the afternoon polar orbit,” Zinser said. “This reinforces the need to make the constellation more robust.”

Zinser also warned that if Congress funds the four-satellite GOES-R program below the $980 million level requested for fiscal year 2015, launch of the first satellite, now scheduled for the second quarter of 2016, could be delayed.

The GOES-R development program was restructured in its early phases to control costs, something Zinser said created new issues that have not yet been fully addressed.

“We found that NOAA oversight and GOES-R program management did not sufficiently address problems with the first re-plan that could now lead to increased costs—and NOAA may have to launch a satellite without all of the core ground system capabilities implemented,” he said.

Meanwhile, Zinser said his office has an ongoing investigation after nearly 20 government employees and consultants for the GOES-R ground segment went to see the movie “Star Trek: Into Darkness” in mid-2013 while on the clock. Since then, more than $3,500 that was charged to the government has been returned, he said.

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.