Jan 23, 2013: Frigid Temps Continue; Snow Friday Night

Forecast Highlights

Another very cold day has been observed across the area, with high temperatures only peaking in the upper 10s to low 20s across the area, about 15-20 degrees below average for some locations. These frigid temperatures will continue through the weekend, with lows tonight and tomorrow night approaching 0 degrees inland. A storm will affect the area on Friday with light snow accumulations, followed by a temporarily warmer pattern for next week ahead of a colder early February pattern.

Tonight – Thursday: Frigid Temperatures Continue

As of 12 AM, temperatures are generally in the mid 0s inland and the upper 0s to low 10s for the rest of the area, with low to mid 10s in NYC and parts of Long Island. Temperatures will continue to drop slightly tonight, and are expected to bottom out near zero degrees for interior locations and the mid 0s to low 10s for the rest of the area.

Clearing skies are expected on Thursday as a minor snow event in the southern Mid Atlantic races offshore, later undergoing through rapid intensification into an extremely intense and massive 930mb storm in the northern Atlantic Ocean, away from land. Highs on Thursday will remain significantly colder than average, peaking again in the upper 10s to low 20s across the area. Stronger NW winds are expected as well, with gusts likely around the 30 mph range, resulting in wind chills near to below zero across most of the area.

Friday – Weekend: Snow, Then Cold Again

The outlook for Friday has been difficult over the last few days – what initially appeared to be a widespread moderate snowstorm significantly changed on the model guidance, which has struggled to handle the setup for the storm over the last few days but is currently coming closer to a consensus. The original expectation for a strong Ohio Valley low pressure is no longer valid, with a 1012mb weak low pressure expected to move east through the Great Lakes region as widespread snow showers spread across the Northeast US region. A low pressure will develop off the coast, but with a lack of enough amplification and a trough axis too far east for a much stronger low to develop and track closer to the coast, this will remain a progressive and fast moving low pressure, intensifying too late and too far offshore for a widespread moderate snowstorm to affect the region.

While the expectation for a high confidence of snow to fall across the area with accumulations has not changed, the overall evolution of the storm and thus the accumulation range have changed, and latest indications are pointing to more of a light accumulating snow event, with light snow developing in the mid afternoon hours on Friday, lasting through the early-mid overnight hours before ending as the storm quickly races offshore. Snow to liquid ratios are expected to be higher than the standard 10:1 ratio, with at least 1 to 2 inches of snow likely across the area. Accumulations may be locally higher especially further east and south of NYC. A final accumulation forecast will be posted with Thursday’s update.

Behind the storm, another short round of cold temperatures is expected with highs on Saturday peaking in the mid to upper 20s across the area, and lows dropping into the upper 0s to low 10s inland and the low to mid 10s for the rest of the area, slightly higher near NYC and the immediate coast. Temperatures will slightly warm on Sunday into the upper 20s to low 30s.

Next Week: Temporarily Warmer, Some Rain

By next week, the pattern will temporarily turn warmer for the region with a trough developing in the western US with a moderately negative PNA, as well as the trough lifting out of the region resulting in rising heights aloft across the region and warmer temperatures, back into the 30s and 40s for highs. This time period will be associated with increased cloudiness, with light rain/snow possible north of NYC on Monday, followed by additional showers by the late week with a cold front passage expected. More information on the pattern for early-mid February, currently shaping up to be another cold one but not as cold as this week, will be posted with the next pattern outlook.