Higher Summits Forecast

Mountain weather is subject to rapid changes and extreme conditions. Always be prepared to make your own assessment of travel and weather conditions. This outlook is one tool to help you plan a safe trip. Always travel with adequate clothing, shelter, food, and water.
Friday, July 3, 2009
5:04 AM

The upper level trough that has been steering our weather over the past several days will continue its gradual movement towards the Northeast over the forecast period. During this time, two areas of low pressure will influence our weather. The first is an area of surface low pressure, currently over NY State, will be dragged along the Saint Lawrence River Valley, continually spinning in spokes of unsettled weather. The second will be a low ride along the fringes of the trough, currently over PA, which will ride up the coast later this afternoon into the evening. As a result, rain showers are expected through the forecast period, and after diurnal heating sets off some instability, afternoon thunderstorms may pass. Some stronger convective cells may contain heavy rains, small hail, or high winds in addition to frequent lightning. Tomorrow, steadier rain will become more intermittent with convective cells as the centers of the lows begin to depart. A weak ridge that will begin to build behind the departing low will tighten the pressure gradient resulting in increasing winds. Winds will also shift from a mild southwesterly flow today to a cooler northwesterly flow by tomorrow. The cooler, drier northwesterly flow may allow for some afternoon clearing tomorrow. But with ample low level moisture being seen wrapping around the low this morning on water vapor satellite images, this seems unlikely until possibly Sunday at the earliest. Wind chills are also being reintroduced to the forecast as it will feel like it is below freezing by tomorrow afternoon. Some other notes to keep in mind: Fog will continue to be dense at times during the forecast, especially today with fog starting at about 4000 feet, if not lower this morning. This will make travel between cairns above treeline slow going and easily disorienting. This fog will also make spotting of incoming thunderstorms difficult and dangerous. Slick rocks and trails acting like creeks will make for slow travel as well. And although temperatures will be mild today, the wet weather is prime for hypothermia if you are not wearing the proper clothing. Hypothermic chances will be further increased tomorrow with the addition of the winds and cooler temperatures. Anyone planning on coming up should be prepared to hike down as well.

Ryan Knapp
Staff Meteorologist
Forecast

Today:

In the clouds w/ rain showers likely and a chance of thunderstorms.

Highs: upper 40s°F

Wind: SW shifting W 10-25 mph increasing to 20-35 mph w/ higher gusts likely

Tonight:

In the clouds w/ rain showers likely and a chance of evening thunderstorms.

Lows: lower 40s°F

Wind: W 20-35 mph increasing to 25-40 mph w/ higher gusts likely

Tomorrow:

Mostly in the cloudy under mostly cloudy skies w/ rain showers likely early then a chance of afternoon shower/thunderstorms. Wind chills 20-30 above.

Highs: mid 40s early falling to upper 30s by the afternoon°F

Wind: W shifting NW 25-40 mph increasing to 40-55 mph w/ higher gusts

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