Weather Journal: Short Chill Before December Heat Wave

Thursday’s weather will mark this week’s temperature nadir, with the “warmest” readings some 20 degrees colder than Tuesday’s near-record highs.

Temperatures will top out in the low-40s over most of the region. Luckily, brisk northwest winds associated with Wednesday’s cold front should die down enough to keep wind-chill values above freezing. It will still feel much, much colder than it did earlier this week, even if the temperatures are only a degree or two below normal for this time of year.

The return to near-normal early December weather won’t last long. In another day or two, it will be right back into the seasonally adjusted frying pan.

Temperatures from Saturday through next Tuesday will all be 10 to 15 degrees warmer than average once again as a series of Midwestern low-pressure centers funnel warm air and moisture up from the deep South. Rain chances also look to return to the region by Monday, with showers possibly heavy at times.

Until then, skies should become increasingly cloudy as temperatures begin their second unseasonable warmup in the span of a week.

Federal Forecasters Rethink Hurricane Standards

In response to criticism during and after superstorm Sandy, the National Hurricane Center on Wednesday disclosed potential changes to the official definition of a hurricane warning for next year.

The changes, first reported by AccuWeather, are intended to prevent a repeat Sandy scenario in which no official hurricane warnings were issued for Greater New York despite forecasts for record levels of coastal flooding. There is reason to suspect that a lack of clear warnings from federal meteorologists may have confounded local officials charged with weighing evacuation decisions.

Chris Vaccaro, a spokesman for the National Weather Service, said that the proposed changes would allow forecasters to issue watches and warnings for threatening storms that fall short of the hurricane standard. ”The current threshold for hurricane status requires sustained winds in excess of 74 miles per hour, in addition to a fully tropical “warm core” structure. It was this last measure that the hybrid superstorm Sandy failed to attain.

“As part of our review of the 2012 hurricane season, including the Sandy service
assessment, we will review all policies and changes through the existing and established process,” he said.

The National Hurricane Center previously announced an effort to address the mismatch between hurricane warnings based on wind speed and storm surges. According to an interactive map published by The Wall Street Journal, the majority of Sandy victims in New York City died of drowning.

Link: http://blogs.wsj.com/metropolis/2012/12/05/weather-journal-short-chill-before-december-heat-wave/