bmc10 Posted February 23, 2011 Share Posted February 23, 2011 the juxtaposition of some key features is also important to note. the 18z nam at 48 hours has a 989mb surface low in upstate new york. more importantly, the dynamics are through the roof at that time. there's a small area of 110+kt 300mb winds in the warm sector and the exit region of the upper level jet. the warm front is already over southern new england at this hour. the 500mb trough and associated forcing/ascent is still back to the west..this could be a wind producer especially further to the south where there is better low level moisture and temperatures are even into the 60's over the mid atlantic. for our area...we have to watch the more synoptic wind potential which will come with the heavy rain and insane isentropic lifting. cool synoptic event being advertised by the 18z nam. we will have to wait and see if it has the right idea, or if it's overly dynamic. The abundant amount of moisture being lifted by these insane dynamics and the strong isentropic lift will result in strong latent instability. Winds should mix down to the surface nicely, I believe especially as the front swings through the area from W to E. This might be another situation warranting advisories for wind. Link to comment Share on other sites More sharing options...
bmc10 Posted February 23, 2011 Share Posted February 23, 2011 It will be interesting to see how things play out.Back on 3/5/08 we got a pre dawn squall line to race through a day after a MDT Risk to our south. We'll have to watch for later runs to see the specifics.Sometimes the best LLJ runs just out ahead of developing warm sector convection.The models are obviously hitting the heavy rain with the warm front but we'll have to see what kind of warm sector development there will be. Yea I think the main threat will be heavy downpours, and when the front moves through, strong winds in association. Areas down south where lapse rates are steeper have the increased threat of some embedded convection. Link to comment Share on other sites More sharing options...
bluewave Posted February 23, 2011 Share Posted February 23, 2011 Yea I think the main threat will be heavy downpours, and when the front moves through, strong winds in association. Areas down south where lapse rates are steeper have the increased threat of some embedded convection. The 18z GFS looks interesting hinting at heavy rains right around the time the LLJ really cranks up overhead. I should see some nice gusts right here on the South Shore. Link to comment Share on other sites More sharing options...
A-L-E-X Posted February 23, 2011 Share Posted February 23, 2011 BW, do you think this storm or the one next week will come close to giving us the kind of winds we saw last March? BTW looks like lots of flood watches out in PA-- those areas that still have a lot of snowpack might have some big flooding issues-- as well as areas downstream from them Link to comment Share on other sites More sharing options...
Diego Posted February 24, 2011 Share Posted February 24, 2011 The west coast is the place to be for snow right now. Up to 8" in Seattle and Portland-- the latest theyve had significant snow since 1989! And it might even snow all the way down to San Fran! We know Feb 1989 sucked around here and was great on the West Coast, but what happened in March 1989? From San Frans' NWS AFD this afternoon: ...FOR SF BAY AND SOUTHWARD...THE BIG QUESTION REMAINS HOW FAST SNOW LEVELS WILL FALL AND HOW MUCH PRECIP WILL STILL AROUND. GOOD AGREEMENT THAT LEVELS SHOULD START BETWEEN 2000 AND 3000 FEET THURSDAY AND DROP CLOSE TO 1000 FEET BY FRIDAY. WHERE THERE IS LESS AGREEMENT IS HOW MUCH MOISTURE WILL STILL BE AROUND WHEN THE LEVELS HIT LOW VALUES. CURRENT THINKING IS THE BULK OF THE PRECIP WILL HAPPEN BEFORE LEVELS ARE ABLE TO DROP. FOR NOW HAVE A WINTER STORM WATCH FOR LOCATIONS ABOVE 1000 FEET FROM SF BAY SOUTHWARD. BEHIND THE FRONT THINGS COULD GET INTERESTING ON FRIDAY AS VERY COLD AIR FILTERS IN HELPING TO KICK OFF MORE SHOWERS. ANY OF THESE HAVE THE POTENTIAL TO BRING A RAIN/SNOW MIX DOWN TO SEA LEVEL BY LATE FRIDAY AFTERNOON THROUGH FRIDAY NIGHT. AT THIS TIME ACCUMULATIONS ARE NOT EXPECTED ON ROADS AT SEA LEVEL.... and SF's latest forecast: CAZ006-241745- SAN FRANCISCO- 125 PM PST WED FEB 23 2011 .TONIGHT...PARTLY CLOUDY. LOWS IN THE MID 40S. NORTHWEST WINDS 15 TO 20 MPH. .THURSDAY...CLOUDY. A CHANCE OF SHOWERS. HIGHS IN THE UPPER 40S. WEST WINDS 10 TO 15 MPH. .THURSDAY NIGHT...SHOWERS LIKELY. LOWS IN THE LOWER 40S. SOUTHWEST WINDS 15 TO 20 MPH. .FRIDAY...SHOWERS LIKELY. HIGHS IN THE MID 40S. WEST WINDS 10 TO 20 MPH. CHANCE OF SHOWERS 70 PERCENT. .FRIDAY NIGHT...PARTLY CLOUDY. A CHANCE OF SHOWERS AND SNOW SHOWERS. LOWS IN THE UPPER 30S. NORTHWEST WINDS 15 TO 20 MPH. CHANCE OF PRECIPITATION 40 PERCENT. .SATURDAY...PARTLY CLOUDY. A SLIGHT CHANCE OF SHOWERS AND SNOW SHOWERS. HIGHS IN THE LOWER 40S. .SATURDAY NIGHT AND SUNDAY...MOSTLY CLEAR. LOWS IN THE UPPER 30S. HIGHS IN THE LOWER 50S. .SUNDAY NIGHT...PARTLY CLOUDY. LOWS IN THE LOWER 40S. .MONDAY...MOSTLY CLOUDY. HIGHS IN THE MID 50S. .MONDAY NIGHT...MOSTLY CLOUDY. A SLIGHT CHANCE OF SHOWERS. LOWS IN THE MID 40S. .TUESDAY THROUGH WEDNESDAY...MOSTLY CLOUDY. A CHANCE OF RAIN. HIGHS IN THE UPPER 50S. LOWS IN THE UPPER 40S. In addition, winter storm warnings were posted throughout the entire coastal region of Washington State and Oregon right down to sea level. Link to comment Share on other sites More sharing options...
bmc10 Posted February 24, 2011 Share Posted February 24, 2011 The 18z GFS looks interesting hinting at heavy rains right around the time the LLJ really cranks up overhead. I should see some nice gusts right here on the South Shore. Yep agreed. The reality is a strong lp to our west and a strong hp to our east with a true s wind can really bring strong winds to the south shore of LI. Interesting that once the front passes, extremely strong cold n winds are possible for the interior, from w to e. This is in response to the strong lp moving to our east and the hp to our west. All around windy scenario just coming in two punches for different areas. Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 24, 2011 Share Posted February 24, 2011 00z NAM now even wetter Link to comment Share on other sites More sharing options...
nycsnow Posted February 24, 2011 Share Posted February 24, 2011 You guys think winds will reach warning criteria? Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 24, 2011 Share Posted February 24, 2011 This reminds me so much of the big system last March, except there was still a decent sized snowpack near places like West Milford which really added to the run off. Let's hope the system early next week cuts far enough north west that we more or less end up with a frontal passage. Link to comment Share on other sites More sharing options...
EasternLI Posted February 24, 2011 Share Posted February 24, 2011 Well I'm glad there's not much snow on the ground. SNE is having a G2G to build an ark Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 24, 2011 Share Posted February 24, 2011 Well I have a fair amount, 6"+ with big piles left over but its not anywhere close to the monster 30"+ I had a month ago which was loaded with water content. Link to comment Share on other sites More sharing options...
nycsnow Posted February 24, 2011 Share Posted February 24, 2011 High wind watch NYC NJ LI CT Link to comment Share on other sites More sharing options...
earthlight Posted February 24, 2011 Author Share Posted February 24, 2011 06z NAM was very impressive with convection on the thermal boundary Friday. Some serious wind problems could arrive both in the warm sector convection and in response to the cold front. this could be pretty exciting. when surface lows track into central new york in later winter or spring, our area often has some very dynamic weather. Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 24, 2011 Share Posted February 24, 2011 John, What do you think will be the biggest threat with this system, straight line wind damage, flash flooding, flooding? Link to comment Share on other sites More sharing options...
earthlight Posted February 24, 2011 Author Share Posted February 24, 2011 John, What do you think will be the biggest threat with this system, straight line wind damage, flash flooding, flooding? Flooding shouldn't be a tremendous issue aside from areas which still have a snowpack or high moisture content. The winds and convection will probably be the biggest hazard although obviously, with heavy rain always comes the potential for some flooding. Low topped convection, if it does develop, could be a real disaster with the winds just off the deck. 06z NAM still advertising 30+kt 10m winds in spots. We will have to carefully monitor the progress of the warm front to see where the localized warm sector sets up. Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 24, 2011 Share Posted February 24, 2011 Flooding shouldn't be a tremendous issue aside from areas which still have a snowpack or high moisture content. The winds and convection will probably be the biggest hazard although obviously, with heavy rain always comes the potential for some flooding. Low topped convection, if it does develop, could be a real disaster with the winds just off the deck. 06z NAM still advertising 30+kt 10m winds in spots. We will have to carefully monitor the progress of the warm front to see where the localized warm sector sets up. Thanks John! Up here we still have about 6"+ with scattered higher amounts. Definitly nowhere near what we had a month ago though. I would think the system for Sunday into Monday probably stands out as a bigger flooding threat since the ground should be saturated and the rivers will already be on the rise. Any chance of organized severe outside of winds that are mixed down to the surface? Link to comment Share on other sites More sharing options...
bluewave Posted February 24, 2011 Share Posted February 24, 2011 Yep agreed. The reality is a strong lp to our west and a strong hp to our east with a true s wind can really bring strong winds to the south shore of LI. Interesting that once the front passes, extremely strong cold n winds are possible for the interior, from w to e. This is in response to the strong lp moving to our east and the hp to our west. All around windy scenario just coming in two punches for different areas. Especially here on Long Island, this looks like one of the more impressive southerly flow high wind events that we have seen in a while shaping up for tomorrow. Link to comment Share on other sites More sharing options...
NorEaster27 Posted February 24, 2011 Share Posted February 24, 2011 Especially here on Long Island, this looks like one of the more impressive southerly flow high wind events that we have seen in a while shaping up for tomorrow. im wary with water temps in the 30s, I noticed the canal was frozen this morning. Link to comment Share on other sites More sharing options...
tornadojay Posted February 24, 2011 Share Posted February 24, 2011 Link to comment Share on other sites More sharing options...
nycsnow Posted February 24, 2011 Share Posted February 24, 2011 How strong will th winds get? What 12z nam have? Link to comment Share on other sites More sharing options...
tornadojay Posted February 24, 2011 Share Posted February 24, 2011 How strong will th winds get? What 12z nam have? 12Z NAM shows peak 10M winds occurring just after the frontal passage between 0Z and 03Z. The highest winds on eastern long island.. 35-40 mph and generally 30-35 mph in NYC metro.. but this does not take into account gusts that will likely occur, which will be much stronger. Link to comment Share on other sites More sharing options...
bluewave Posted February 24, 2011 Share Posted February 24, 2011 im wary with water temps in the 30s, I noticed the canal was frozen this morning. In some respects it reminds me of March 5th,2008.This time around the gradient will be stronger with a longer duration of winds.That morning a squall line raced through before dawn the day after a MDT risk to our south.This time I think that the strong winds should ramp up between 12-15z and last into the afternoon and then shift W-NW around evening. http://www.erh.noaa....ns/03052008.txt Link to comment Share on other sites More sharing options...
A-L-E-X Posted February 24, 2011 Share Posted February 24, 2011 Especially here on Long Island, this looks like one of the more impressive southerly flow high wind events that we have seen in a while shaping up for tomorrow. In a while eh-- Im wondering if this could surpass last March. That would be pretty difficult, because of how extreme that event was for us. Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 24, 2011 Share Posted February 24, 2011 New river forecasts coming out, flood stage will be approached Link to comment Share on other sites More sharing options...
IrishRob17 Posted February 24, 2011 Share Posted February 24, 2011 New river forecasts coming out, flood stage will be approached I had 11" of snow pack in my yard this morning and the Wallkill River still has lots of ice on it at least along my house so things could get interesting up this way depending on how it all plays out. Link to comment Share on other sites More sharing options...
bluewave Posted February 24, 2011 Share Posted February 24, 2011 In a while eh-- Im wondering if this could surpass last March. That would be pretty difficult, because of how extreme that event was for us. That one goes in my easterly events folder.That was my greatest high wind event since 11/11/95.Only on the rarest occasions do I see gusts here approaching the 75 mph range.There was really no inversion in place for that storm. Tomorrow should be interesting around here.The GFS looks like it forecasting a line to push through here around 15z-16z which could bring down gusts in the 50-60 mph range.The surface gradient on its own is very impressive during the day and evening. Later on the winds shift W-NW and may gust 50-60 mph again.We'll see if parts of the island can record some peak gusts over 60 mph. Link to comment Share on other sites More sharing options...
A-L-E-X Posted February 24, 2011 Share Posted February 24, 2011 Im glad the first part of this event will be during the day How high were the winds on 11/11/95-- I dont remember that event at all. Also, do you think we'll get the same kind of winds with the storm next week? Link to comment Share on other sites More sharing options...
bluewave Posted February 24, 2011 Share Posted February 24, 2011 Im glad the first part of this event will be during the day How high were the winds on 11/11/95-- I dont remember that event at all. Also, do you think we'll get the same kind of winds with the storm next week? 11/11/95 was amazing here.That one had some surface based instability during the best LLJ so I estimated sustained winds here near the peak around 45-50 mph with gusts to 70-75 mph.The night sky was repeatedly being lit up by really bright power flashes.I was lucky that my power stayed on but the western half of town was without power until the next day. Link to comment Share on other sites More sharing options...
Jersey Devil Posted February 24, 2011 Share Posted February 24, 2011 New river forecasts coming out, flood stage will be approached where do you find river forecasts? I have all my sites bookmarked for the river gauges and such....though since the flood gate project was started years ago (and now completed) nothing makes sense anymore. I used to know exactly where on the gauges I was safe, and where I was not. I would however like to see the river forecasts...... Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 24, 2011 Share Posted February 24, 2011 where do you find river forecasts? I have all my sites bookmarked for the river gauges and such....though since the flood gate project was started years ago (and now completed) nothing makes sense anymore. I used to know exactly where on the gauges I was safe, and where I was not. I would however like to see the river forecasts...... http://water.weather.gov/ahps/ Not all have been updated yet but they have been coming out since about 9:30 this morning. Link to comment Share on other sites More sharing options...
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