Go Back   Winnipesaukee Forum > Winnipesaukee Forums > Weather
Home Forums Gallery YouTube Channel Classifieds Links Calendar Register FAQDonate Members List Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
Old 06-09-2008, 09:37 AM   #1
CanisLupusArctos
Senior Member
 
CanisLupusArctos's Avatar
 
Join Date: Jan 2007
Location: Center Harbor
Posts: 1,033
Thanks: 12
Thanked 420 Times in 96 Posts
Default Severe Weather Tues June 10?

NOAA's Storm Prediction Center has outlined much of New England, including all of Vermont and New Hampshire, in a risk for severe thunderstorms tomorrow (Tuesday.)

While our hot and humid weather continues, a cold front will be moving south and east into New England tomorrow. Along and ahead of it, thunderstorms will develop in the morning in western NY state and will move east during the day. They will reach our area during the heat of the day (which will reach low 90s.)

This hot and humid air will rise rapidly as the cold air starts to nose underneath it and lift it. The rising action will form thunderstorms, and several of them may become severe.

A severe thunderstorm is defined as having damaging wind and/or damaging hail.

The greatest threat is in the CT river valley (as always, it seems) where the storms will most likely roll through in mid-afternoon. At that time we will probably notice the sky getting darker along the lake's western shores.

Severe weather is very localized and very spontaneous in nature, so therefore tomorrow's forecasts will have a much better handle on it. This is just early warning.

In the wake of the cold front, we will lose the humidity and dry out again (just in time for pine pollen, yayyyyy.) Temps will be 10 degrees cooler. Long range GFS-MRF looks like it's calling for the weather to remain 80/dry through the weekend, and then an omega block for bike week. We'll see. After last winter I wasn't trusting the GFS-MRF much but it did seem to call this heat wave pretty well, a week in advance. Bike week weather is probably a whole new thread.

First thing's first, however... potentially damaging thunderstorms tomorrow (Tuesday) afternoon. There is also a threat today in Vermont, and it's possible that one or two of those storms may stray this way later on today.


SPC's technical discussion for tomorrow follows.

...NERN STATES...
A SHORTWAVE TROUGH ALONG THE BASE OF THE NRN PLAINS UPR LOW WILL
TRANSLATE NEWD INTO THE MIDWEST BY EARLY TUESDAY...THEN BRUSH THE
NERN STATES TUESDAY AFTN/EVENING. ATTENDANT COLD FRONT WILL
LIKEWISE PROGRESS EWD INTO NY AND THE CNTRL APLCNS BY EARLY TUE
AFTN...THEN OFF THE COAST BY 12Z WED. AHEAD OF THE PRIMARY SYNOPTIC
FRONT...A LEE-TROUGH WILL EXIST FROM VA NWD INTO ERN NY.

A BAND OF TSTMS WILL LIKELY EXIST INVOF THE COLD FRONT FROM ONTARIO
SWD INTO THE LWR OH VLY AT 12Z TUESDAY. AIR MASS AHEAD OF THE FRONT
WILL REMAIN VERY WARM AND HUMID THROUGH THE DAY WITH MLCAPES OF
2000-3000 J/KG. TSTMS SHOULD DEVELOP IN WEAKER INHIBITION OVER THE
OH VLY BY LATE MORNING AS LARGE SCALE HEIGHT FALLS ASSOCD WITH THE
UPR TROUGH TRANSLATE NEWD. THESE STORMS WILL PROGRESS EWD DURING
PEAK HEATING AND WILL LIKELY MERGE WITH OTHER STORMS DEVELOPING NEAR
THE LEE-TROUGH LATE IN THE AFTN/EVENING.

STRONGER VERTICAL SHEAR OF 35-45 KTS WILL TEND TO BE RELEGATED TO
THE OH VLY NEWD INTO NY AND CNTRL/NRN NEW ENGLAND WHERE ORGANIZED
STORMS...INCLUDING SUPERCELLS...ARE POSSIBLE. GIVEN THE
UNIDIRECTIONAL FLOW REGIME...QUICK TRANSITIONS INTO BOWING LINE
SEGMENTS WILL BE FAVORED WITH DMGG WIND GUSTS/HAIL...ESPECIALLY
GIVEN THE VERY HOT BOUNDARY LAYER. ATTM...IT APPEARS BEST
JUXTAPOSITION OF DEEP LAYER SHEAR...FORCING FOR ASCENT AND
INSTABILITY WILL OCCUR FROM CNTRL/ERN PA NWD INTO CNTRL/ERN NY AND
WRN NEW ENGLAND. TSTMS WILL PROGRESS EWD TOWARD THE COAST AFTER
DARK WITH A LIKELY RAPID DIMINISHING TREND.
CanisLupusArctos is offline   Reply With Quote
Old 06-09-2008, 01:06 PM   #2
phoenix
Senior Member
 
phoenix's Avatar
 
Join Date: Apr 2004
Location: phoenix and moultonboro
Posts: 1,089
Thanks: 12
Thanked 138 Times in 98 Posts
Default

thanks CLA i find your postings very helpful as the TV stations tend to cover their local area and not the lakes region
__________________
it's tough to make predictions specially about the future
phoenix is offline   Reply With Quote
Old 06-09-2008, 01:24 PM   #3
CanisLupusArctos
Senior Member
 
CanisLupusArctos's Avatar
 
Join Date: Jan 2007
Location: Center Harbor
Posts: 1,033
Thanks: 12
Thanked 420 Times in 96 Posts
Default

You're welcome. I love doing this. Especially when it works out. LOL

I do have two updates.

1) The severe weather threat for today has been expanded to include all of New Hampshire, not just areas north and west of here. This isn't widespread activity we're expecting today, but merely pulse-type thunderstorms resulting from this hot humid air being so unstable, you could almost get it to rise/form thunderheads just by coughing (not quite, but you get the point.) Some of today's pulse-type thunderstorms (the kind Florida gets almost every afternoon) may reach severe limits and it'll be a crap-shoot as to which towns will get one and which ones won't.

2) For anyone still wondering what's been causing all this severe weather across the country, here's today's watch/warning map. The blue rectangular box is a Severe Thunderstorm Watch. Note the presence of winter storm watches in Montana! This is June? The cold air is pouring southeastward out of Canada. In its path, a high pressure system (clockwise circulation) is off the east coast pumping air from the Gulf of Mexico up to us. The cold air (enough to make the snow come down in June!) is providing a trigger for all this unstable hot/humid air.

The cold air will modify as it makes the trip across the country, but will still be more than enough to trigger widespread destabilizing of this hot/humid stuff.
Attached Images
 
CanisLupusArctos is offline   Reply With Quote
Old 06-10-2008, 09:53 AM   #4
CanisLupusArctos
Senior Member
 
CanisLupusArctos's Avatar
 
Join Date: Jan 2007
Location: Center Harbor
Posts: 1,033
Thanks: 12
Thanked 420 Times in 96 Posts
Default Tornado Watch #499

There is moderate risk for severe weather in New Hampshire today. Moderate is part of a very sensitive scale where "slight risk" is an average summertime severe weather threat, moderate is worthy of respect, and high risk is usually worthy of national news coverage.

The Storm Prediction Center in Norman OK has issued Tornado Watch #499 for all of Vermont, most of New York state, northwest Connecticut, and northeast Pennsylvania. This watch is in effect from 10:05 am until 6 pm today. It DOES NOT include New Hampshire at the moment, although I would not be surprised at all to see it expanded into New Hampshire as the day goes on. At the very least, I think we will see SPC issue a severe thunderstorm watch for NH... but they are the professionals when it comes to these things, not me.

Even if it is not... severe weather is a bigger threat today than we have seen in a while. I don't think we've seen a moderate risk for at least a couple years, but I don't know off-hand and it really doesn't matter.

What matters is for everyone to stay tuned to local weather forecasts and NOAA Weather Radio throughout the day and keep an eye to the sky.

A line of thunderstorms is now forming in New York state and has just passed Rochester. They are moving toward the ENE with an average forward speed of 45 mph. These storms are already producing large hail.

More storms will be developing as the heat of the day builds. The highest risk for tornadoes today is currently over Vermont, according to the SPC. Still, the probability over NH isn't much less.

Here are the probabilities associated with today's severe weather threat, as indicated by the SPC:

Probability of 2 or more tornadoes
Mod (40%)

Probability of 1 or more strong (F2-F5) tornadoes
Low (20%)

Probability of 10 or more damaging wind events
High (>95%)

Probability of 10 or more damaging hail events
High (>95%)

Probability of 6 or more combined severe hail/wind events
High (>95%)


Storms will weaken as they near the coast, especially the Maine coast, where a sea breeze has been keeping things in the 50s and 60s. Temperatures everywhere else are already well into the 80s and will top out in the mid-90s. Humidity is very high today, with dewpoints around 70 in most parts of NH. This extreme heat and humidity will be the fuel for the thunderstorms as a cold front arriving from the west provides the trigger.
CanisLupusArctos is offline   Reply With Quote
Old 06-10-2008, 12:07 PM   #5
NHKathy
Senior Member
 
NHKathy's Avatar
 
Join Date: Sep 2004
Location: Moultonborough when I can / RI
Posts: 699
Thanks: 180
Thanked 38 Times in 22 Posts
Default

Quote:
Originally Posted by CanisLupusArctos View Post
Storms will weaken as they near the coast, especially the Maine coast, where a sea breeze has been keeping things in the 50s and 60s. Temperatures everywhere else are already well into the 80s and will top out in the mid-90s. Humidity is very high today, with dewpoints around 70 in most parts of NH. This extreme heat and humidity will be the fuel for the thunderstorms as a cold front arriving from the west provides the trigger.
CLA, I always hear this from the weather forecasters down here in RI, why is this exactly? - I have been curious - they always tend to weaken as they approach the coast...
NHKathy is offline   Reply With Quote
Sponsored Links
Old 06-10-2008, 12:32 PM   #6
CanisLupusArctos
Senior Member
 
CanisLupusArctos's Avatar
 
Join Date: Jan 2007
Location: Center Harbor
Posts: 1,033
Thanks: 12
Thanked 420 Times in 96 Posts
Default

Storms weaken as they approach the coast because the cooler, marine air is very stable. It doesn't rise very well in summertime because usually it's the coolest air around. Warm air doesn't really rise on its own -- it's more like, "cooler air is heavier and pushes the warm air out of the way." Since cold air likes to hog the floor, the warm air must get displaced UP.

That is what's happening today: Very hot and humid air mass direct from the Gulf of Mexico, sitting right over us. It's ready to rise if cold air comes along.

The cold front (leading edge of cold air) is moving out of Canada, as cold fronts have been doing all winter and spring. The hot/humid stuff has gotten in its way, like a cow on RR tracks. The cold air will act as the "cow catcher" on the front of it (old-style locomotive). It slides underneath the warmer air ("cow") and tosses it up. As it rises, all the humidity in it condenses into clouds and eventually raindrops, and hailstones from above the freezing level. Today those updrafts (and the thunderheads they feed) may actually reach 50,000 feet, higher than most airliners ever fly.

When the cold front nears the ocean, it doesn't find this lightweight heat anymore, but 55-degree marine air. What's behind the front is actually warmer than what's over the ocean, so the whole action I described above will probably not work very well over the water today. It's like the locomotive will encounter a bionic cow on steroids that's actually the heavier entity. Therefore the storms will quickly lose their updrafts as they move off the coast.

Update: Severe Thunderstorm Watch #500 is now in effect for all of NH (except extreme SW) and most of Maine until 10 pm. Tornado Watch #499 remains in effect for Vermont and NY state until 6 pm.
CanisLupusArctos is offline   Reply With Quote
Old 06-10-2008, 01:12 PM   #7
SIKSUKR
Senior Member
 
SIKSUKR's Avatar
 
Join Date: Apr 2004
Posts: 5,052
Thanks: 215
Thanked 892 Times in 504 Posts
Default

The ocean air will effectively "cut the legs out from under" thunderstaorms.As CLA pointed out,the ocean temps are very cold and cold air does not rise which is how cumulus(the towering dark clouds we call thunder clouds) are formed.If you have spent a lot of time near the NE ocean,you will often see the clouds forming over land if the air is a little unstable and you will see a sharp cut-off right at the ocean where it will be totally clear.This is because the heating of the earth warms the air which in turn rises,then cools and condenses to form the clouds.The warm sun cannot warm the air over the cool ocean and thus no rising air to form cumulus clouds.
__________________
SIKSUKR
SIKSUKR is offline   Reply With Quote
Old 06-10-2008, 01:38 PM   #8
Rose
Senior Member
 
Join Date: Aug 2002
Posts: 498
Thanks: 62
Thanked 71 Times in 32 Posts
Default Cumulonimbus

Quote:
Originally Posted by SIKSUKR View Post
...cumulus(the towering dark clouds we call thunder clouds)...
Actually, thunderstorm clouds are cumulonimbus...cumulus on steroids.
Rose is offline   Reply With Quote
Old 06-10-2008, 01:57 PM   #9
chipj29
Senior Member
 
chipj29's Avatar
 
Join Date: Apr 2004
Location: Bow
Posts: 1,852
Thanks: 480
Thanked 285 Times in 151 Posts
Default

Northern NY and VT are getting pummeled right now by heavy storms. They look to be moving east/northeast, and missing us far to the north. Will more storms fire up farther south? Maybe....

BTW it hit 98 in my area today...yikes.
chipj29 is offline   Reply With Quote
Old 06-10-2008, 02:15 PM   #10
SIKSUKR
Senior Member
 
SIKSUKR's Avatar
 
Join Date: Apr 2004
Posts: 5,052
Thanks: 215
Thanked 892 Times in 504 Posts
Default

Quote:
Originally Posted by Rose View Post
Actually, thunderstorm clouds are cumulonimbus...cumulus on steroids.
Ah yes Rose I am very familiar with the cumulonimbus.I think I wrote it a little wrong.I meant to describe that cumulos clouds in general were formed by rising air.I know you are the real expert here.You need to chime in more on CLA's weather threads.
__________________
SIKSUKR
SIKSUKR is offline   Reply With Quote
Old 06-10-2008, 02:47 PM   #11
Rose
Senior Member
 
Join Date: Aug 2002
Posts: 498
Thanks: 62
Thanked 71 Times in 32 Posts
Default

Dick Albert used to give weather quizzes, and one of the questions asked to pick the technical name for a thunderstorm. One of the choices was nimbo bimbo! I think he should have used that as a nickname for mammatus.
Rose is offline   Reply With Quote
Old 06-10-2008, 03:00 PM   #12
CanisLupusArctos
Senior Member
 
CanisLupusArctos's Avatar
 
Join Date: Jan 2007
Location: Center Harbor
Posts: 1,033
Thanks: 12
Thanked 420 Times in 96 Posts
Default

I second that: Rose needs to chime in more often and so does R2B! Rose, I love your reminder of the 'Nimbo Bimbo'... I grew up watching those weather quizzes and loved them. Amazing the things they used to be able to say on TV without offending everyone.

On the ocean's effect we should point out that cumulus clouds and thunderheads (cumulonimbus) DO form over the ocean, but most often in the tropics where the ocean water is in the 80s or 90s. That process (hurricane development) follows a slightly different set of physics rules from what we're having right now, which is why those storms get names. You will also see clouds form over the ocean in winter, when the ocean is significantly warmer than the air. That leads to ocean effect snow, and lake effect snow, and sometimes it is part of a growing snowstorm.

UPDATE: SPC has issued more severe weather watches in a continuous line from Maine down to North Carolina. The tornado watch for western NY state has been converted over to a Severe Tstorm watch. The rest of the tornado watch remains in effect for eastern NY and all of VT. Storms are firing all up and down the east coast.

The storms in VT do appear to be missing us, at the moment. Once the watch box has been issued, it's a dice-roll as to where in the box the "watched" weather will occur. Anywhere in the box, or near it, is the rule, at anytime.

If it does happen, a warning is issued by the local NWS office for the specific county where it's happening.

Currently most of the state of VT is under a severe thunderstorm WARNING in addition to the tornado watch.

Looking at the national map, I'm amazed at the variety of weather on it... the severe weather outbreak here, and the snow in the western states. This is what happens when the late-winter cold hangs around long enough to meet the summertime heat.
Attached Images
 
CanisLupusArctos is offline   Reply With Quote
Old 06-10-2008, 03:22 PM   #13
paddler
Member
 
Join Date: May 2007
Posts: 24
Thanks: 0
Thanked 8 Times in 3 Posts
Default

A friend of mine just observed a 23 degree temperature drop in a little over an hour in the NEK of VT.

http://www.robertlyonsphotography.com/webcam/?page_id=8

Last edited by paddler; 06-10-2008 at 03:23 PM. Reason: added link to weather station
paddler is offline   Reply With Quote
Old 06-10-2008, 03:26 PM   #14
CanisLupusArctos
Senior Member
 
CanisLupusArctos's Avatar
 
Join Date: Jan 2007
Location: Center Harbor
Posts: 1,033
Thanks: 12
Thanked 420 Times in 96 Posts
Default Rapid storm growth

This afternoon's storms are now taking on a rapid-development trait over the lakes region.

The sun is still shining over Winni but in the last 2 minutes there has been sudden thunder. Radar indicates it's from a storm that just popped up over Squam Lake (or thereabouts) and is moving NE. It will likely grow as it goes.

This sort of development means that it will be easier to get caught off-guard because there's no way to track storms when they're forming out of clear air right on top of you.

Based on this, more storms will fire up over the area this afternoon and many of them will grow to severe limits very quickly. Other storms will move into the area from the west or southwest.
CanisLupusArctos is offline   Reply With Quote
Old 06-10-2008, 08:42 PM   #15
This'nThat
Senior Member
 
This'nThat's Avatar
 
Join Date: Dec 2006
Posts: 534
Thanks: 19
Thanked 134 Times in 61 Posts
Default

Quote:
Originally Posted by CanisLupusArctos View Post
Looking at the national map,.....
... I see the Winter Storm is still hanging around the Northwest, where they picked up nearly a foot of snow today in the foothills and mountains of Washington state and Montona.
This'nThat is offline   Reply With Quote
Old 06-10-2008, 09:16 PM   #16
CanisLupusArctos
Senior Member
 
CanisLupusArctos's Avatar
 
Join Date: Jan 2007
Location: Center Harbor
Posts: 1,033
Thanks: 12
Thanked 420 Times in 96 Posts
Default

Yup, and there are at least two ski areas (including Aspen CO) that are opening this weekend for more spring skiing.

The severe thunderstorm watch for NH and ME has been extended until midnight. Severe storms will be moving through here during the next hour. Then we can use this thread for damage reports if needed.
CanisLupusArctos is offline   Reply With Quote
Old 06-10-2008, 10:14 PM   #17
Resident 2B
Senior Member
 
Resident 2B's Avatar
 
Join Date: Apr 2004
Location: Bradenton, FL and North Shore, MA
Posts: 1,331
Thanks: 922
Thanked 295 Times in 150 Posts
Default

The line really bowed out as it crossed I93 headed to the lake. This is usually a sign of high wind and we had a good wind the last 20 minutes near the Weirs.

Scanner is very active. There was a lightning strike at Franklin Hospital, but with minor damage, thank God.

R2B
Resident 2B is offline   Reply With Quote
Old 06-10-2008, 10:26 PM   #18
Airwaves
Senior Member
 
Join Date: Feb 2006
Location: I'm right here!
Posts: 1,153
Thanks: 9
Thanked 102 Times in 37 Posts
Default 1117 Doppler Radar report

Special Weather Statement
National Weather Service Gray Me
1117 Pm Edt Tue Jun 10 2008

Mez018-023-nhz010-013-014-110400-
Coastal Rockingham-coastal York-interior Rockingham-interior
York-strafford-
1117 Pm Edt Tue Jun 10 2008

...strong Thunderstorms Will Impact Strafford County...york County
And Rockingham County Through Midnight Edt...

At 1117 Pm Edt National Weather Service Doppler Radar Indicated A
Line Of Strong Thunderstorms Extending From 3 Miles Southeast Of
Ossipee To 10 Miles East Of Concord...moving East At 35 Mph.
This Cluster Of Strong Thunderstorms Will Affect Areas In And Around
Parsonsfield...strafford...newfield...limerick...f armington...
Middleton...deerfield...candia...shapleigh And Milton Through
Midnight Edt.

Hail Up To One Half Inch In Diameter...heavy Downpours...frequent
Cloud-to-ground Lightning And Gusty Winds To 45 Mph Can Be Expected.
Airwaves is offline   Reply With Quote
Old 06-10-2008, 10:30 PM   #19
Airwaves
Senior Member
 
Join Date: Feb 2006
Location: I'm right here!
Posts: 1,153
Thanks: 9
Thanked 102 Times in 37 Posts
Default Quick update

Belknap Nh-carroll Nh-
1126 Pm Edt Tue Jun 10 2008

...the Severe Thunderstorm Warning For Carroll And Belknap Counties
Expires At 1130 Pm Edt...

A Severe Thunderstorm Watch Remains In Effect Until Midnight Edt
Wednesday Morning For Western Maine And New Hampshire.

Lat...lon 4361 7166 4368 7165 4370 7152 4382 7156
4390 7151 4392 7136 4409 7139 4413 7135
4409 7135 4408 7132 4414 7130 4416 7101
4354 7100 4358 7118 4351 7120 4335 7117
4331 7123 4359 7173
Time...mot...loc 0326z 269deg 49kt 4411 7054 4389 7060
4362 7066
Airwaves is offline   Reply With Quote
Old 06-10-2008, 11:22 PM   #20
CanisLupusArctos
Senior Member
 
CanisLupusArctos's Avatar
 
Join Date: Jan 2007
Location: Center Harbor
Posts: 1,033
Thanks: 12
Thanked 420 Times in 96 Posts
Default Damage report

R2B is right, the scanner is busy after this storm passed. Meredith FD has just been called out to 112 Jeness (sp?) Hill Road for tree on the wires.

The lightning is still pretty vivid out there, the rain still falling. Highest wind gust at Black Cat was actually earlier in the day though, when we had one of our usual southeast sundown winds exceed 30 mph. The storm itself had some good wind to it but didn't exceed 30 mph. Just enough rain to give the grass and garden what they need for the night. By the look of the radar, we should be clearing within the hour. Warnings just issued for the Boston suburbs for severe thunderstorms with a forward speed of 62 mph... SW to NE. That's like Great Plains storms do. You don't see that around here too often.
CanisLupusArctos is offline   Reply With Quote
Old 06-11-2008, 08:46 AM   #21
Grant
Senior Member
 
Grant's Avatar
 
Join Date: Jul 2002
Location: Pennsyltuckey & Tuftonboro
Posts: 1,394
Thanks: 197
Thanked 142 Times in 78 Posts
Default

And, in the wake of the storm, the cams are all showing the seasonal yellow tide of pine pollen. Looks like a lot again this year. Bummer.
__________________
"When I die, please don't let my wife sell my dive gear for what I told her I paid for it."
Grant is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -5. The time now is 09:33 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.

This page was generated in 0.41188 seconds