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WEDNESDAY EVENING: RIVER LEVEL RISES ARE SLOWING...FORECAST UPDATE KEEPS WATER JUST BELOW THE LEVEES IN VERY CLOSE SHAVE; PARTIAL BREAK-UP OF MILL POND DAM BRINGS CONCERNS FOR POTENTIAL TOTAL DAM FAILURE AND RAPID FLOODING OF SOME OF WASHBURN AND WADE

NOTE:  A more recent post has been issued.  See the mattnoyes.net homepage for latest posts.

8:00 PM Update:  You can see for yourself in the graph below (graph and live look at Fort Kent webcam were posted in the prior update...found just below this one) - the observed river height of the St. John River - that the rises in river levels are starting to slow.  This could be a tremendous turn of fortune if the current trend continues, and the Northeast River Forecast Center has ammended their forecast down just slightly in the latest update, but just slightly is, frankly, all we need right now. The new forecast is a fraction of a foot to nearly one foot less than the previous forecast, and while that's not much in the scope of forecasting a river's water level, literally a couple of inches can make the difference between catastrophe and major disaster averted. Though river levels can be tricky and each river can respond differently, if the current slowing trend continues in the river rise, the water may stay below the levee through the time of crest around or just after midnight tonight. (Video provided by my station's website, NECN.com - serving all of New England including Northern Maine)

But there are other concerns in Aroostook County, as well.  In a situation like this - where so much water is flowing through our rivers and streams - dams that often have been forgotten for years can suddenly become the center of attention.  That's become the case for the Mill Pond Dam on the Salmon Brook, upstream from the Aroostook River.  This dam is giving way on its upper end, and once a dam starts to break down, the structural integrity of it is compromised.  That does NOT always mean you're destined to find complete dam failure - we saw a few similar situations to this in Massachusetts and New Hampshire the past two years in the major spring flood events there, and disaster was averted in most of those cases as the dams began to breach, but in the end held.  Unfortunately, simply speaking on statistics, the chance of a total dam breach increases dramatically once part of the structure has been compromised.  It's for this reason that the National Weather Service issues a Flash Flood Warning before the dam actually breaks - and some evacuations may be voluntary or mandatory from local emergency management officials.  Those residents in Washburn and Wade, Maine, if suggested by local authorities to evacuate, should do so without hesitation.  A dam failure is much more sudden than river flooding like we're seeing on the St. John - when the National Weather Service statement refers to a six to seven foot wall of water crashing down the Salmon Brook and into the Aroostook River, that is a real potential.  Unfortunately, these type of dam failures give residents near the waterway only seconds to minutes for response - not nearly enough time to drive out of the area, and usually not even enough time to know the dam has actually burst.  So...if you're told to leave, be sure to do it, knowing that the risk of staying is simply too high, but hoping that - like our counterparts to the south in springs past - the dam will find a way to hold.

Have a thought or observation?  Share it in the comment section of this post.

WEDNESDAY EVENING: RIVER LEVEL RISES ARE SLOWING...FORECAST UPDATE KEEPS WATER JUST BELOW THE LEVEES IN VERY CLOSE SHAVE; PARTIAL BREAK-UP OF MILL POND DAM BRINGS CONCERNS FOR POTENTIAL TOTAL DAM FAILURE AND RAPID FLOODING OF SOME OF WASHBURN AND WADE

NOTE:  A more recent post has been issued.  See the mattnoyes.net homepage for latest posts.

8:00 PM Update:  You can see for yourself in the graph below (graph and live look at Fort Kent webcam were posted in the prior update...found just below this one) - the observed river height of the St. John River - that the rises in river levels are starting to slow.  This could be a tremendous turn of fortune if the current trend continues, and the Northeast River Forecast Center has ammended their forecast down just slightly in the latest update, but just slightly is, frankly, all we need right now. The new forecast is a fraction of a foot to nearly one foot less than the previous forecast, and while that's not much in the scope of forecasting a river's water level, literally a couple of inches can make the difference between catastrophe and major disaster averted. Though river levels can be tricky and each river can respond differently, if the current slowing trend continues in the river rise, the water may stay below the levee through the time of crest around or just after midnight tonight. (Video provided by my station's website, NECN.com - serving all of New England including Northern Maine)

But there are other concerns in Aroostook County, as well.  In a situation like this - where so much water is flowing through our rivers and streams - dams that often have been forgotten for years can suddenly become the center of attention.  That's become the case for the Mill Pond Dam on the Salmon Brook, upstream from the Aroostook River.  This dam is giving way on its upper end, and once a dam starts to break down, the structural integrity of it is compromised.  That does NOT always mean you're destined to find complete dam failure - we saw a few similar situations to this in Massachusetts and New Hampshire the past two years in the major spring flood events there, and disaster was averted in most of those cases as the dams began to breach, but in the end held.  Unfortunately, simply speaking on statistics, the chance of a total dam breach increases dramatically once part of the structure has been compromised.  It's for this reason that the National Weather Service issues a Flash Flood Warning before the dam actually breaks - and some evacuations may be voluntary or mandatory from local emergency management officials.  Those residents in Washburn and Wade, Maine, if suggested by local authorities to evacuate, should do so without hesitation.  A dam failure is much more sudden than river flooding like we're seeing on the St. John - when the National Weather Service statement refers to a six to seven foot wall of water crashing down the Salmon Brook and into the Aroostook River, that is a real potential.  Unfortunately, these type of dam failures give residents near the waterway only seconds to minutes for response - not nearly enough time to drive out of the area, and usually not even enough time to know the dam has actually burst.  So...if you're told to leave, be sure to do it, knowing that the risk of staying is simply too high, but hoping that - like our counterparts to the south in springs past - the dam will find a way to hold.

Have a thought or observation?  Share it in the comment section of this post.

WHILE NORTHERN MAINE FLOODS, ALL OF NEW ENGLAND FREEZES...LITERALLY!

Note:  See special post on record Maine flooding on homepage, www.mattnoyes.net.

Not a lot of change to the general thoughts laid out here last night, except that the trend is slightly closer to New England with the upcoming front late week and weekend, but overall impact on the forecast should be small.

In the meantime, surface ridge axis will move overhead tonight and Thursday, bringing nearly calm overnight wind with dry and cool air in place.  Diurnal cumulus clouds resulting from the upper level disturbance and the cold pool aloft contrasting with relatively warm land will dissipate, and this means clearing skies, light wind and dry air - great conditions for radiational cooling.  Therefore, I expect colder conditions tonight than were seen last night for most of New England with widespread frost and freeze - freeze found through most of the interior.  Tender plants will either have to be covered (risky given how cold it will be) - or brought inside.

Thursday is quiet here at home but PA gets into showers associated with a gentle isentropic lift on the cool side of a stationary front draped across that state.  The front will also house plenty of clouds, but with an extended surface ridge developing beneath the confluent flow over New England and Eastern Quebec, we should hold these clouds off.  As the ridge builds in, broad but only weak to moderate warmth and moisture streams in after having been stronger over Pennsylvania with a swath of rain, and this will bring the clouds over New England on Friday, with the rain weakening as it moves east but still capable of bringing some rain to southwest New England Thursday night, then carrying scattered showers into New England on Friday.  As the warm advection weakens, though, so too will the showers, so that at least 60% of New England is unlikely to record measurable precipitation on Friday, and the other 40% is likely to find showers mostly in the morning.

Thereafter, I still like the idea of amplifying the ridge, and actually bridging the ridging from Eastern Canada up and down the Eastern US coast.  This leaves us with the omega block described yesterday, and slows the atmosphere enough to squeeze out a decent Saturday and then only slowly bring in the moisture ahead of the next upper low coming in from the west and breaking down the block on Sunday.  I'm not sure it's quite this easy, though, with regard to sky cover, though this description should apply to precip changes.  The sky cover challenge comes from the warm and moist advection clouds on Friday being leftover under a building ridge that may result in an inversion for a time Friday evening, that will have to be mixed out Friday night to get rid of the clouds.  Given a drying and cooling flow that sets in Friday night, it seems like we should succeed in mixing out the clouds on Saturday, though differential advection of warm aloft and cold at the surface will keep those clouds around into Saturday morning.  That always makes me nervous with an easterly component to the wind, but for now I think we can bet on some erosion of the clouds for Saturday, especially during the afternoon.

That's all for today.

Matt

MAINE FLOOD POST ON THE HOMEPAGE

A special post about Northern Maine flooding is on the homepage, www.mattnoyes.net.  I will update the daily discussion soon, but wanted to get that out first.

Matt

URGENT UPDATE: LATEST RIVER FORECAST INUNDATES FORT KENT, MAINE OVERNIGHT TONIGHT

Note:  An update has been issued since this post.  See most recent post at mattnoyes.net homepage.

The situation is dire and only expected to get worse in the coming hours.  The St. John and Fish River have both responded to the combination of snowmelt and heavy rain, and have been rising steadily and quickly.  The rivers are reaching record flood levels, and will continue rising into the overnight Wednesday night.  With the new, revised forecast from the National Weather Service's Northeast River Forecast Center, Environment Canada and the United States National Weather Service both agree that the St. John River at Fort Kent Maine will rise to 31 feet - enough to top the earthen levee that protects the center of town, inundating Fort Kent in the northernmost tip of New England.  Residents have been working hard to keep the river in check and have been working to raise the levees where they can, but in the end the power of the water will, without question, be too much for these efforts if it does indeed reach the 31 foot mark.

Downtown Fort Kent resembles a ghost town at this hour, with numerous roads and the center of town closed except to those working to build up the levees and, moreover, prepare the town for inundation.  This is not uncharted territory for me as a meteorologist, NECN as a station, or New England as a whole.  This is the third consecutive year we've recorded major or record flooding in New England, and this new routine is one that repeatedly leaves new folks with flooded homes and businesses.  I will update tips for after the flooding in the coming 24 hours, but for now, the advice is to follow all evacuation orders - they are based on history and science, not guesswork.  Remember that flooding is the number one cause of death by weather - folks either trying to drive through floodwaters, or not leaving their homes when the waters rise.  We are hearty in Northern Maine - three foot snowstorms are simply a reason to take the snowmobile - but the power of water is one we must respect.

Webcam from Fort Kent from SJV Wireless:

Latest forecast for Fort Kent, Maine, from the Northeast River Forecast Center:

The following pictures were sent to NECN by Peter Cyr, from the University of Maine at Fort Kent.  NECN has compiled a slideshow of some pictures that I've featured in the video embed here, or it can be viewed directly by clicking here to jump to NECN.com.  Scroll down farther in this post to see additional pictures I've posted, with some description of what we're looking at.  Many thanks for the tremendous effort put forth by Peter to get these amazing pictures to us.

We urge folks never to drive through floodwaters - if the car stalls, you're stuck until you're swept away.  But this does give perspective of a neighborhood town:

This next picture is only the beginning of flooding for this part of Fort Kent near the St. John, but is a heartbreaking sign of what's in store.

The picture that follows illustrates just how much water is flowing into town...and this is only from what is technically "moderate" flooding along the St. John River.  A huge contributor to the problems is the Fish River, which is carrying a tremendous amount of rain and snowmelt, and the confluence of these two rivers is a big problem with flooding.  The earthen bump in the foreground, seen with the bridge in the background is the levee that appears as though it will overtopped.  To the left of the levee is the way to the center of town - with an elevation lower than where the river level would be...hence the major problem.  Next, a closeup of the bridge - the International Bridge that runs from Fort Kent, Maine, to Clair, New Brunswick - closed for obvious reasons with the water level so high and the force so strong it's threatening the structure.  Of course, just a short way inland is the town center, where folks have been preparing for high water.  Though it may look like a ghost town with the police blocking off the major roads of Fort Kent, many folks have been busy preparing for the water - taking valuables out of basements and lower levels of homes, and preparing for evacuation. 
Have a thought or observation?  Share it in the comment section of this post.

URGENT UPDATE: LATEST RIVER FORECAST INUNDATES FORT KENT, MAINE OVERNIGHT TONIGHT

Note:  An update has been issued since this post.  See most recent post at mattnoyes.net homepage.

The situation is dire and only expected to get worse in the coming hours.  The St. John and Fish River have both responded to the combination of snowmelt and heavy rain, and have been rising steadily and quickly.  The rivers are reaching record flood levels, and will continue rising into the overnight Wednesday night.  With the new, revised forecast from the National Weather Service's Northeast River Forecast Center, Environment Canada and the United States National Weather Service both agree that the St. John River at Fort Kent Maine will rise to 31 feet - enough to top the earthen levee that protects the center of town, inundating Fort Kent in the northernmost tip of New England.  Residents have been working hard to keep the river in check and have been working to raise the levees where they can, but in the end the power of the water will, without question, be too much for these efforts if it does indeed reach the 31 foot mark.

Downtown Fort Kent resembles a ghost town at this hour, with numerous roads and the center of town closed except to those working to build up the levees and, moreover, prepare the town for inundation.  This is not uncharted territory for me as a meteorologist, NECN as a station, or New England as a whole.  This is the third consecutive year we've recorded major or record flooding in New England, and this new routine is one that repeatedly leaves new folks with flooded homes and businesses.  I will update tips for after the flooding in the coming 24 hours, but for now, the advice is to follow all evacuation orders - they are based on history and science, not guesswork.  Remember that flooding is the number one cause of death by weather - folks either trying to drive through floodwaters, or not leaving their homes when the waters rise.  We are hearty in Northern Maine - three foot snowstorms are simply a reason to take the snowmobile - but the power of water is one we must respect.

Webcam from Fort Kent from SJV Wireless:

Latest forecast for Fort Kent, Maine, from the Northeast River Forecast Center:

The following pictures were sent to NECN by Peter Cyr, from the University of Maine at Fort Kent.  NECN has compiled a slideshow of some pictures that I've featured in the video embed here, or it can be viewed directly by clicking here to jump to NECN.com.  Scroll down farther in this post to see additional pictures I've posted, with some description of what we're looking at.  Many thanks for the tremendous effort put forth by Peter to get these amazing pictures to us.

We urge folks never to drive through floodwaters - if the car stalls, you're stuck until you're swept away.  But this does give perspective of a neighborhood town:

This next picture is only the beginning of flooding for this part of Fort Kent near the St. John, but is a heartbreaking sign of what's in store.

The picture that follows illustrates just how much water is flowing into town...and this is only from what is technically "moderate" flooding along the St. John River.  A huge contributor to the problems is the Fish River, which is carrying a tremendous amount of rain and snowmelt, and the confluence of these two rivers is a big problem with flooding.  The earthen bump in the foreground, seen with the bridge in the background is the levee that appears as though it will overtopped.  To the left of the levee is the way to the center of town - with an elevation lower than where the river level would be...hence the major problem.  Next, a closeup of the bridge - the International Bridge that runs from Fort Kent, Maine, to Clair, New Brunswick - closed for obvious reasons with the water level so high and the force so strong it's threatening the structure.  Of course, just a short way inland is the town center, where folks have been preparing for high water.  Though it may look like a ghost town with the police blocking off the major roads of Fort Kent, many folks have been busy preparing for the water - taking valuables out of basements and lower levels of homes, and preparing for evacuation. 
Have a thought or observation?  Share it in the comment section of this post.

MERCURY TO IMPRESS IN MAY

Yesterday we examined the potential of an out-of-control Mercury that could put an end to life as we know it...even if the odds of it happening in the next few billion years is only one percent!  ;)  Today, I thought this article from Sky and Telescope was worth passing along as a note of beauty from the planet...Mercury will put on a rare and enjoyable show during the month of May - for the naked eye observer the first half of the month, and for those who enjoy the view through the telescope during the latter half!  (Photo courtesy Pete Lawrence, from his website).

MERCURY TO IMPRESS IN MAY

Yesterday we examined the potential of an out-of-control Mercury that could put an end to life as we know it...even if the odds of it happening in the next few billion years is only one percent!  ;)  Today, I thought this article from Sky and Telescope was worth passing along as a note of beauty from the planet...Mercury will put on a rare and enjoyable show during the month of May - for the naked eye observer the first half of the month, and for those who enjoy the view through the telescope during the latter half!  (Photo courtesy Pete Lawrence, from his website).

SHARP, AMPLIFIED PATTERN TO SET UP BRIEF OMEGA BLOCK THIS WEEKEND

Late discussion today due to lots of travel for a public appearance so will keep it brief...

Expected minor to moderate flooding underway in Northern New England from the Northeast Kingdom of VT east thru Northern NH and much of ME.  Flooding primarily is of smaller rivers and streams, though larger rivers will respond to runoff through the night.  It's been fun to watch the change to snow in the high terrain of the Greens as the low level convergent band/frontal zone evident all day on radar through bright banding echoes moves east and marks the leading edge of the cold.  That change to solid precipitation marches east through the mountains of NH and ME this evening and tonight.  Elsewhere, as the storm pulls thru ME we find dry air wrapping under the belly of the low - just like it did already across the Mid-Atlantic.

The upper low moves overhead tomorrow and it's nothing to scoff at.  Not only an impressive collection of absolute vorticity, but also a cold pool below -30 C, and that's impressive!  I realize the model RH fields have been supportive of only scattered clouds, but that just doesn't compute with clearing Tue Night skies allowing for diurnal heating of the land, and the steep lapse rate that results.  This should promote healthy cumulus growth that will fill the sky by afternoon, and vertical development should be sufficient for some convective showers to blossom, especially where assisted by orography.  Might be a bit tougher to get any measurable precipitation in the downsloped areas with a northwest wind, but even there the convective instability should succeed in wringing out some light precipitation.

As the upper low departs, an intriguing 500 mb pattern readies in the skies overhead.  The bottom line is extreme amplification of the pattern, and the trick is determining exactly where the ridge axis lines up between the upper low moving over the Canadian Maritimes and the next upper low over the Great Lakes.  This essentially creates a sharp Omega Block - low, high, low, from west to east - that serves as a block of flow for weather systems.  That's why it's so important to nail the ridge axis in the forecast, because on the west side of the ridge, sharp warm advection will create clouds and showers, and on the east side a low level northeast wind with moisture is possible, so the potential for bust is there.  I followed the Canadian Operational and Ensembles in the forecast today, with some support from the ECMWF early in the period, though I feared it was a bit too bullish with holding the ridge later in the weekend, so brought the chance of showers in for Sunday as the warm advection nudges east with the Omega Block potentially breaking down as the ridge gets pinched off to the north as a closed high.  This may set up a favorable scenario for a Rex Block later in the game - high over low - but that's far from certain.  As for temps, both the synoptic setup and statistical guidance give good agreement on somewhere around 60, and that's what I followed.

Matt

TUESDAY DISCUSSION TO BE DELAYED...

Another distant appearance today.  Won't be able to update until I get home this evening....

Matt