Hazardous Weather Outlook

Hazardous Weather Outlook (HWO)
The Weather Center of JBreezy
Original Post: 2:47 PM – THURS. Feb. 16th, 2012
Update Posted: 12:20 AM - FRI. Feb. 17th, 2012

This HWO is for much of the Eastern U.S., especially in PA.

Days One and Two: Thursday & Friday

A cold front will exit the Mid-Atlantic States tonight, primarily producing rain. A brief period of snow in the northern portions cannot be ruled out. The front will clear New England by Friday Evening.

Days three through five: Saturday through Monday

A low pressure system located over the SW States will head east toward Texas & Louisiana tonight & tomorrow. After arrival, the upper-level low will open up into the flow to the north. While the exact track remains uncertain, it appears more likely that a nor’easter will head in for early next week. This scenario depends on five things: phasing (the upper-level (UL) cut-off low rejoining the main trough to the north), the Newfoundland low, a weak cold front over the Great Lakes, a surface high in the Eastern Plains, and where the nor’easter is in relation to a jet streak.

The phasing is the biggest factor; the other factors will not matter if phasing is too late. Therefore, until the UL cut-off low opens up tomorrow night, uncertainty will be too great to forecast the nor’easter’s track accurately. On the flip side, most models agree that the low will be in the right place near the jet streak for maximum UL divergence; hence, the surface low will be quite strong.

For now, a 50% or greater probability of 6+” to fall sits approximately from Nashville, TN to the Washington, D.C. area.

Stay tuned for further updates on the possible nor’easter.

Thanks to Brian Edwards from AccuWeather. His discussion was very helpful in creating this.