Powerful storms were threatening communities across the country Tuesday with weather ranging from fire in the Southern High Plains to blizzards in the Midwest.Forecasts also predicted dust storms in the southwest, tornadoes in the South and blizzard conditions in the Central Plains, and were forcingforcing some changes to Mardi Grasin New Orleans. The city moved up and shortened the celebrations two biggest parades. Police were also expected to help keep the parades moving to the finish before winds picked up, authorities said.The weather wasnt stopping Shalaska Jones and her 2-year-old daughter from waving at passing Mardi Gras floats Tuesday and hoping to catch one of the coveted coconuts thrown to the crowd.We was coming out rain, sleet, or snow, Jones said.The alarming forecast was one of the first big tests for the National Weather Service afterhundreds of forecasters were fired last weekas part of President Donald Trumps moves to slash the size of the federal government. Former employees said the firing of meteorologists who make crucial local forecasts across the U.S.could put lives at risk.Country faces a number of weather threatsDust storms brought near-zero visibility to parts of New Mexico and west Texas on Monday, prompting the National Weather Service to issue Dust Storm Warnings. Widespread blowing dust was expected Tuesday, said the weather service office covering Midland and Odessa, Texas.The weeks strong weather system will bring a threat of blizzard conditions, high winds, flash flooding, severe weather, dust storms, and critical to extreme fire weather conditions to the nations heartland, according to a weather service update Monday.The Central Plains and Midwest were bracing for blizzard conditions later Tuesday that forecasters warned could make travel treacherous and potentially life-threatening. The Nebraska Department of Transportation warned that conditions could mean low visibility and whiteout conditions across the state and urged travelers to adjust their plans for Tuesday afternoon and into the night.On Tuesday, twisters, damaging winds, and large hail were all possible as a strong storm system was set to move across the nations midsection into Arkansas, Louisiana, and Mississippi, the federal Storm Prediction Center warned. Tornado watches and warnings were issued Tuesday morning in Oklahoma, Texas, and Arkansas.Storms that swept through Texas and Oklahoma early Tuesday morning brought high winds and rain, overturning tractor-trailers and damaging roofs. Power outages were climbing Tuesday morning in the storms wake, with nearly 400,000 customers without power in Texas and another 25,000 knocked offline in Oklahoma, according toPowerOutage.us, which tracks outages nationwide.The bulls-eye for a heightened risk of severe weather was an area stretching from east Texas to Alabama thats home to more than seven million people. Cities under threat included Baton Rouge and Shreveport in Louisiana; Jackson, Mississippi; and Mobile, Alabama.Region braces for severe weather during Mardi GrasNew Orleans Police Superintendent Anne Kirkpatrick ordered parade-goers to not bring umbrellas, tents, or anything that could fly in the wind and cause mayhem.Just outside New Orleans in neighboring Jefferson Parish, officials canceled planned Mardi Gras Day parades due to anticipated high winds and thunderstorms.This is disappointing, but our top priority is ensuring the well-being of everyone in our community, and we must always prioritize safety above all else, Jefferson Parish President Cynthia Lee Sheng said in a statement.Mardi Gras floats could become unstable and heavy winds could blow down trees and power lines, the National Weather Service warned, adding gusts of up to 60 mph (97 kph) were expected Tuesday afternoon.In Pointe Coupee Parish, near Louisianas capital city of Baton Rouge, the incoming weather forced drastic changes to one of the oldest Mardi Gras celebrations in the state. The parade there was scheduled to roll without any bands, marching teams, or dance groupsa staple of Carnival Season parades.Officials also moved up the start time and urged residents to immediately remove all tents and trash afterward due to the dangers they can present during weather.Other cities with Mardi Gras parades watching forecastsElsewhere, large crowds were expected Tuesday for Mardi Gras celebrations in Mobile, Alabama. Police said they were monitoring the forecast and would announce any celebration changes.Other cities hosting large events included Biloxi, Mississippi, where an annual parade was set for Tuesday afternoon.In downtown Pensacola in the Florida Panhandle, organizers were planning a Big Easystyle festival that included food trucks, dancing, live entertainment, and a low country seafood boil.Jeff Martin and Jack Brook, Associated PressAssociated Press writers Sara Cline, Freida Frisaro, and Susan Montoya Bryan contributed to this report.