First Frost - Fall 2008

CanisLupusArctos · 09-10-2008, 09:45 AM

First frost of the new fall season is likely in many areas across the state
late tonight and tomorrow morning. Yesterday's thunderstorms and heavy rain
were caused by a cold air moving down from Canada, and it has now taken control.
With the cold air, high pressure is building into New England and will be
centered over us tonight. This will result in clear and calm conditions that
are perfect for radiational cooling. With no wind or cloud cover to help hold
some heat near the surface after dark, expect today's 65-degree warmth to
radiate back into space. Cold air will fall to the low spots such as valleys
while mountain summits will be a few degrees warmer.

Expect an end to the growing season across many mountain valleys in the northern
half of the state tonight, but there will be areas of frost scattered around the
rest of the state including the seacoast area. Temperatures in the mountain
valleys will likely drop to near 30 while the rest of the state should be within
3 degrees of 40. Remember... sub-freezing temperatures are not required for
frost to occur. To protect plant leaves from frost, cover them or bring them
inside.

Where there are bodies of water there will be fog resulting from the water
giving up its summertime heat to the cold dry air. Those traveling on nearby
roads may find travel delays due to the fog on Thursday morning. Any fog will
burn off within the first two hours of sunlight.

twoplustwo · 09-10-2008, 11:12 AM

I'm not sure whether to be happy this might help my allergies, or be sad that my pumpkins and squash needed more time.

murph · 09-10-2008, 02:37 PM

What is the forecast for this weekend in the lakes region?

This'nThat · 09-10-2008, 08:19 PM

Forecast for this weekend.

CanisLupusArctos · 09-11-2008, 10:43 AM

This weekend low pressure will pass to our north and then deepen in the Canadian Maritimes on Sunday afternoon through Monday. Things may get a little more humid on Friday into Saturday but will become unsettled as the low's associated cold front approaches from the northwest.

This will be the leading edge of more below-average temps for this time of year. High pressure will build behind the front later in the day on Sunday. As the low pressure to our east becomes even lower pressure at the same time as the high pressure tries to move in here, this will create a steepening gradient over us on Sunday night and Monday which means windy. Air flows from where it is, to where it isn't-- from high pressure to low pressure.. and the greater difference/shorter distance between the two, the faster the wind will flow as the high pressure tries to "fill in" the low pressure.)

So this weekend will be a quick battle between the outgoing season and the incoming season. Unsettled weather will be the result (although I can't rule out some sun) and the cold air will win.

Last night's low at Black Cat was 40 F with heat loss fog noted on the water of the lake... water temp down a degree (69) since yesterday.

GWC... · 09-11-2008, 10:47 AM

Looks a bit moist...

Saturday:
http://www.weather.com/maps/maptype/...name=undefined

Sunday:
http://www.weather.com/maps/maptype/...name=undefined

09-10-2008, 09:45 AM	#1
CanisLupusArctos Senior Member Join Date: Jan 2007 Location: Center Harbor Posts: 1,049 Thanks: 15 Thanked 472 Times in 107 Posts	First Frost - Fall 2008 First frost of the new fall season is likely in many areas across the state late tonight and tomorrow morning. Yesterday's thunderstorms and heavy rain were caused by a cold air moving down from Canada, and it has now taken control. With the cold air, high pressure is building into New England and will be centered over us tonight. This will result in clear and calm conditions that are perfect for radiational cooling. With no wind or cloud cover to help hold some heat near the surface after dark, expect today's 65-degree warmth to radiate back into space. Cold air will fall to the low spots such as valleys while mountain summits will be a few degrees warmer. Expect an end to the growing season across many mountain valleys in the northern half of the state tonight, but there will be areas of frost scattered around the rest of the state including the seacoast area. Temperatures in the mountain valleys will likely drop to near 30 while the rest of the state should be within 3 degrees of 40. Remember... sub-freezing temperatures are not required for frost to occur. To protect plant leaves from frost, cover them or bring them inside. Where there are bodies of water there will be fog resulting from the water giving up its summertime heat to the cold dry air. Those traveling on nearby roads may find travel delays due to the fog on Thursday morning. Any fog will burn off within the first two hours of sunlight.

09-10-2008, 11:12 AM	#2
twoplustwo Senior Member Join Date: Dec 2007 Location: Moultonborough Posts: 456 Thanks: 51 Thanked 39 Times in 21 Posts	frost I'm not sure whether to be happy this might help my allergies, or be sad that my pumpkins and squash needed more time.

09-10-2008, 02:37 PM	#3
murph Senior Member Join Date: Apr 2004 Location: Westford/Meredith Posts: 66 Thanks: 0 Thanked 1 Time in 1 Post	Weekend Weather What is the forecast for this weekend in the lakes region?

09-10-2008, 08:19 PM	#4
This'nThat Senior Member Join Date: Dec 2006 Posts: 534 Thanks: 19 Thanked 134 Times in 61 Posts	Forecast for this weekend. Attached Images

09-11-2008, 10:47 AM	#6
GWC... Senior Member Join Date: Apr 2004 Posts: 1,325 Thanks: 5 Thanked 0 Times in 0 Posts	Looks a bit moist... Saturday: http://www.weather.com/maps/maptype/...name=undefined Sunday: http://www.weather.com/maps/maptype/...name=undefined __________________ [Assume funny, clever sig is here. Laugh and reflect... ]

09-11-2008, 10:43 AM	#5
CanisLupusArctos Senior Member Join Date: Jan 2007 Location: Center Harbor Posts: 1,049 Thanks: 15 Thanked 472 Times in 107 Posts	This weekend low pressure will pass to our north and then deepen in the Canadian Maritimes on Sunday afternoon through Monday. Things may get a little more humid on Friday into Saturday but will become unsettled as the low's associated cold front approaches from the northwest. This will be the leading edge of more below-average temps for this time of year. High pressure will build behind the front later in the day on Sunday. As the low pressure to our east becomes even lower pressure at the same time as the high pressure tries to move in here, this will create a steepening gradient over us on Sunday night and Monday which means windy. Air flows from where it is, to where it isn't-- from high pressure to low pressure.. and the greater difference/shorter distance between the two, the faster the wind will flow as the high pressure tries to "fill in" the low pressure.) So this weekend will be a quick battle between the outgoing season and the incoming season. Unsettled weather will be the result (although I can't rule out some sun) and the cold air will win. Last night's low at Black Cat was 40 F with heat loss fog noted on the water of the lake... water temp down a degree (69) since yesterday.