Almost a year after Congress learned of a budget scandal at the National Weather Service, lawmakers are still trying to get a realistic estimate of what it costs to run the nation’s first line of defense against the effects of hurricanes, tornadoes and winter storms.

The National Weather Service has struggled in recent years to find money to operate a nationwide network of forecasting offices while also adding new technology intended to improve predictions. That’s raised doubts about the reliability of a program that produces about 1.5 million forecasts and 50,000 warnings a year, aiding citizens who may be in the path of dangerous storms, farmers trying to protect crops and airlines planning their daily schedules.

The administrator and chief financial officer of the National Weather Service resigned last year after the discovery that millions of dollars had been shuffled without notice from technology accounts in fiscal 2010 and fiscal 2011. The money was used to cover shortfalls in forecasting offices, where salaries are the key cost. There has been no allegation that anyone profited personally from these actions, described in a later investigation as “colorizing” or “washing” money. But agencies are not supposed to take such actions, called reprogramming, without consent from Congress.

Now, the agency’s budget is something of a mess and congressional appropriators have demanded that the NWS give them at least a timeline for when it will be able to deliver a realistic budget. When President Barack Obama signed the fiscal 2013 spending package (PL 113-6) into law March 26, he triggered a 30-day deadline for the agency to deliver a report to Congress with detailed information about how it will prevent future unauthorized shifting of money between accounts.

“Concern remains that the inappropriate movement of funds within the NWS could have jeopardized the NWS’ ability to accurately forecast the weather and that these actions may negatively impact the NWS’ ability to make forecast improvements in the future,” appropriators said in a report that accompanied the spending package. “In addition, dissatisfaction remains with NOAA’s failure to determine the true costs necessary to support NWS operational needs.”

With the sequester stripping $85 billion from federal operating expenses by September, the weather service is facing the June 1 start of the hurricane season with some delays in the development of newer computer systems and a hiring freeze in place. The union representing the agency’s forecasters says that will exacerbate the short staffing that’s already led to fatigue and constant shift-switching at the network of 122 forecasting offices.

This short staffing comes even though the Weather Service has benefited from some relative congressional generosity in recent years. Appropriators last year signed off on a $36 million reprogramming request for the NWS after the improper budgeting was made public, a financial move that made official more reductions of technology accounts in order to prevent furloughs. For fiscal 2013, the appropriators provided the National Weather Service with $926.1 million, a $34 million increase. The bulk of the weather service budget always goes toward the Local Warnings and Forecasts base budget — $655 million in the case of fiscal 2013.

Even amid the current budget crunch, the House lawmaker with direct responsibility for the weather service’s parent Commerce Department has implored the department to make certain the nation’s forecasting offices have the money they need to help the public cope with tornadoes, hurricanes and other storms.

“This committee will be prepared to reprogram,” Rep. Frank R. Wolf, R-Va., chairman of the House Commerce, Justice and Science Appropriations Subcommittee, said at a March 5 hearing. “They should look far out on the horizon. We can find other programs to take it from. No one should be able to say that there have been damages, loss of life or anything because the weather bureau says, ‘We don’t have the money.’”

Wolf’s Senate counterpart, Barbara A. Mikulski, D-Md., has long worried that the National Oceanic and Atmospheric Administration has let its focus on troubled satellite programs overshadow its needs for weather-forecasting operations. Mikulski, who has proposed moving management of the satellite program to NASA, is an ardent booster of Maryland-based NOAA’s forecasting unit.

“Many people don’t realize that the wonderful weather reports they get in their communities come because of the NOAA weather administration,” Mikulski said in 2009. “We all love The Weather Channel, but The Weather Channel depends on NOAA.”

Rep. Chaka Fattah of Pennsylvania, the top Democrat on the House Commerce, Justice and Science Appropriations Subcommittee, says he is confident Congress will get better information on the weather service’s needs for the next budget cycle. To Fattah, the NWS is one of the federal agencies on the front lines of major battles between Democrats and Republicans over the size of the federal government and the programs the public depends on.

“The question is, are we willing to make the decisions needed to fund them,” Fattah said.

The National Weather Service employees union argues that the program’s employees already have seen the effects of restrained domestic spending. Excluding supervisors, the size of the weather service’s workforce has dropped by 193 people since 2010 to 3,684, according to the union.

“Even on fair weather days, offices report overtime and temporary promotions to fill the gaps, leaving forecasters fatigued from working off rotation shifts or shifts with a quick turnaround,” Daniel Sobien, the union president, said in a statement. “In one office, it was called, ‘a scheduling nightmare in which no one works their regular schedule anymore.’”

Sobien said in an interview that short staffing is affecting the quality of the forecasts. The agency has support in Congress, he said, but faces challenges within NOAA.

“For some reason, they weren’t asking for enough money all along,” he said. “NOAA has a lot of competing interests and its own priorities.”