So my parade of forecasts that include nothing but great weather are over. You may have noticed, but it is raining out today. And it looks as if we will not be able to take the chance of rain out of the forecast for maybe the next 7-10 days or so. To illustrate this point, the image above shows 500 mb Heights and Absolute Vorticity. Simple put, it is showing pieces of energy in the upper atmosphere that drive almost all weather events. This image is a forecast from one of our computer guidance products and is for Friday morning at 8 am. Today’s rain is being caused by the green and yellow shaded areas over Southern New England in the image above.
The weekend and early next week’s player in the weather is the 1st big L to our northwest in Canada. This system is reaching the end of it’s life stage and is becoming what is known as a cut-off area of low pressure. When a storm becomes cut-off it turns into a large system that doesn’t move all that much. Leaving the region it impacts with unsettled weather for a few days until something comes and gives it a push to get rid of it. This isn’t to say that it will rain from now through Tuesday; actually most of the time will be relatively dry, but it does give us the chance of rain at basically anytime between now and Tuesday.
Next up on our parade of systems is the area outlined in blue over Arizona and New Mexico. This piece of energy was once Hurricane Miriam in the Eastern Pacific. Miriam moved over colder waters and disapated, but her energy moved onshore and will become our next nuissance towards mid week. Eventually developing into an area of low pressure that will move across the Ohio River Valley and over our heads. Bringing with it the constant chance of showers and rain.
Finally towards the end of next week and next weekend, another system will be dropping out of Canada and moving through the Great Lakes. This system is currently off of the image above; somewhere southwest of Alaska over the Pacific. This system is too far out there to attempt to forecast finer details.
7 Day Forecast
Tonight: Pretty Miserable to put it bluntly. Mist, rain and occasional downpours continue into the night. Overnight lows in the upper 50s. Winds becoming east at 10-15 mph.
Saturday: Misty and rainy to start; gradual clearing throughout the day. Chance of a shower in the afternoon. Highs 60-65.
Saturday Night: Mostly cloudy with a scattered shower. Lows around 55.
Sunday: Cloudy with the chance of a shower. Highs 60-65.
Monday: Chance of a shower. Highs around 65.
Tuesday: Chance of an isolated shower late. Highs around 65.
Wednesday: Chance of an isolated shower. Highs in the low 70s.
Thursday: Scattered showers. Highs in the low 70s.
Tropics
Hurricane Nadine: One lonely Tropical System way out in the Eastern Atlantic which could be one for the record books. Nadine has been classified as a Tropical System for over 20 days now and she has a chance to be one of the longest lived storms in history. She formed from an easterly wave that exited off the African Coast. She then quickly turned towards the north and impacted the Azores Islands. After this, she decided to turn back to the south and is in the process of completing a loop in her path. All the while maintaining Tropical Storm strength and doing all of this very slowly. As for what is going to happen to Nadine, guidance suggests that she will continue her drift to the north only to possibly repeat the loop that she is currently in. Only instead of looping clockwise, she might do it counterclockwise. But eventually she will be picked up and could possibly impact the Azores Islands again. As for what her path has looked like, see below.
-Chris
After last nights wind, rain and scattered power outages, the forecast going forward looks as good as the last one. Maybe just a bit cooler as we count down the last couple days of Summer. Last nights winds were associated with a strong cold front and a strong Low Level Jet. A Low Level Jet is an area of high winds that are lower in the atmosphere than what we call the Jet Streams. The winds from the Low Level Jet last night were allowed to mix down to the surface and thus we had our gusty conditions. But that is all gone now. Looking ahead looks bright and sunny.
7 Day Forecast
Tonight: Clear and cool. Lack of clouds will allow for radiational cooling and will allow temperatures to dip into the low 40s.
Thursday: Sunny with isolated low level clouds. Highs in the upper 60s to near 70.
Friday: More clouds than sun as the cold front that pushed offshore drifts back towards us. Highs in the low to mid 70s depending on the amount of clouds.
Saturday: Sun and Clouds. Highs in the mid to upper 70s.
Sunday: Chance of a shower or storm; especially central and northern New England. Highs around 70.
Monday: Sun and Clouds. Highs in the upper 60s.
Tuesday: Partly cloudy. Highs around 70.
That’s it. There is nothing of relevance going on in the tropics and our weather is pretty calm. But remember, winter is right around the corner and by all accounts looking ahead, it could be a good one for snow. Which of course depends on which way you look at it.
-Chris
Well this is certainly going to be the least exciting post I have done so far. So uneventful in fact that all you need to do is look at the 7 day forecast. High Pressure is in control for the majority of the forecast period. Our only chance of rain during this next week comes Saturday and even that isn’t a slam dunk. An area of low pressure is going to drop down out of Canada and traverse across the Great Lakes and follow the Canadian Border while tracking northeast. The reason I say it is not a slam dunk that we will see rain is that the system could have exhausted all of its energy by then. Meaning that rain will be widely scattered and potentially uneventful. So right to the 7 day. Other than that enjoy this beautiful stretch.
7 Day Forecast
Tonight: Mostly clear. Overnight lows around 50.
Tomorrow: Isolated cloud. Slightly warmer than the day before. Highs in the upper 70s.
Wednesday Night: Clear. Lows in the upper 50s.
Thursday: Chance of fog in the morning. Clear in the afternoon. Warmer. Highs around 80.
Friday: Chance of fog in the morning. Mostly sunny. Chance of a late evening shower in the North Country. Highs in the low 80s.
Saturday: Chance of a shower during the afternoon and into the evening. Highs in the low 80s.
Sunday: Mostly cloudy. Highs in the low to mid 70s.
Monday: Sun and clouds. Highs 70-75.
Tuesday: Sun and clouds. Highs around 75.
Tropics:
Nothing to see hear. The top L was formerly Hurricane Leslie. She made landfall in Newfoundland and will be moving on from there. Tropical Depression Michael is basically just a low level swirl on satellite. And finally Tropical Depression Fourteen will likely become a Tropical Storm and possibly a Hurricane, but it’s best chance of making landfall is in Europe…….
-Chris
From the Storm Prediction Center, it is clear that they have upped the likelihood of a severe weather event occurring today as they have categorized regions just to our west as having a Moderate chance of severe weather occurring within 25 miles of any location.
This image is of the probability of a tornado occurring within 25 miles of a point. A 10% probability is not all that common for our part of the country, but SPC has determined that a large area of the Hudson Valley is worthy of a 10% chance of a tornado.
On to the main threat from today’s storms, wind damage. SPC has put almost all of the region in a 45% hatched outline. Meaning that there is a 45% chance of a wind damage report within 25 miles of a point. The hatching is used when SPC believes that significant severe is possible. And in this case that would mean wind gusts greater than 65 kts or about 75 mph.
Finally the probability of severe hail occurring is fairly low, but not impossible. Given on a 15% chance, this is to be expected due to the type of storm that we will be impacting us.
Thoughts:
Remain unchanged from yesterday. I just feel as if we are too far east and the timing of the cold front is such that we will be impacted during the overnight hours and that the loss of solar heating will lead to the weakening of convection as it marches for the coast. Places west of say Springfield do have a good chance of experiencing some very intense weather as a cold front pushes east through New York State during the day. Convection in the form of a squall line has already begun to form out near Buffalo. This will move east and become better organized and more intense throughout the day. Looking like wide spread wind damage is possible in New York State with isolated tornadoes in spin ups that form in the line. By sunset the squall line will be knocking on New England’s door. Between about 8 pm and 2 am, the line will move through New England and push offshore; with all activity gone by morning. As the line moves from west to east it will weaken. Some damaging wind reports can not be ruled out and some are probably likely in the strongest of storms. But I just feel as we move further into the night, the line will lose its intensity, but will still bring with it thunder and lightning, heavy rain and more importantly it will usher in some much needed cooler air.
Something of note, the latest WRF run that is put out by Millersville University is not all that impressive for our region. It has the line of convection falling apart and breaking into pieces by the time it reaches us. This is something to watch because the Millersville WRF is usually convectively happy; meaning that it loves to go nuts and pop thunderstorms everywhere.
-Chris
From the Storm Prediction Center: they have upped our chances of severe thunderstorms from almost nothing to slight which you can see includes almost all of New England and most of the Mid-Atlantic States.
Also from the Storm Prediction Center this is the Day 2 Probabilistic Forecast. Which shows that a good chunk of Western Central and Southern New England is included a region of 30% hatched probability. While the rest of us lie in the 15 % probability region.
Finally, the below text is from the discussion that the Storm Prediction Center puts out with their individual day forecasts. Below they highlight what I mentioned yesterday; that the warm temperatures coupled with such high dew points will make for a fairly unstable environment. Add in the approaching Cold Front and this gives you the chance of thunderstorms. Add in some of the more complicated dynamics that I will save you from and we get the chance of severe weather.
…ERN PORTIONS OF OH VALLEY…MID ATLANTIC THROUGH NERN STATES…
A PRE-FRONTAL SQUALL LINE WILL LIKELY BE IN PROGRESS SATURDAY
MORNING FROM THE OH VALLEY SWWD INTO THE TN VALLEY. RICH GULF
MOISTURE /UPPER 60S TO 70F DEWPOINTS/ NOW RESIDING OVER THE MID
ATLANTIC AND SRN PORTIONS OF NERN STATES WILL ADVECT THROUGH
REMAINDER OF THE WARM SECTOR SATURDAY AS SLY LLJ STRENGTHENS IN
ASSOCIATION WITH EJECTING SHORTWAVE TROUGH AND DEEPENING SFC LOW.
WEAK MID LEVEL LAPSE RATES AND AREAS OF CLOUDS WILL MITIGATE
INSTABILITY SOMEWHAT. HOWEVER…BREAKS IN CLOUDS SHOULD ALLOW FOR
SOME DIABATIC WARMING OF THE MOIST BOUNDARY LAYER…CONTRIBUTING TO
MLCAPE FROM 500-1000 J/KG. STORMS ARE EXPECTED TO INTENSIFY ALONG
AND AHEAD OF PRE-EXISTING PROGRESSIVE OUTFLOW BOUNDARY AS WARM
SECTOR DESTABILIZES. DEEP LAYER WINDS WILL INCREASE IN ASSOCIATION
WITH THE SHORTWAVE TROUGH AND ITS ATTENDANT SFC LOW WITH LARGE
HODOGRAPHS AND 40+ KT 0-6 KM SHEAR. ORGANIZED STORMS INCLUDING
LEWP/BOWING STRUCTURES AND EMBEDDED SUPERCELLS WILL BE POSSIBLE AS
ACTIVITY DEVELOPS EWD. DAMAGING WIND AND MAYBE A FEW TORNADOES WILL
BE THE PRIMARY THREATS.
As for what I am currently thinking, my thoughts from yesterday about the Cold Front’s position and timing have not changed. I feel as if the Cold Front will be too far to our west for us to be impacted by the storms when they are at their peak intensity. We will however be impacted by the leftovers from New York State as they move east with the Cold Front. This isn’t too say that the storms that impact us overnight won’t be capable of being stronger, I am just saying that I feel as if the greatest chance of severe weather is to our west; simply because regions to our west will be impacted by these storms with the aid of the sun. By the time that they make it to our neck of the woods, the sun will have set and the atmosphere will have begun to stabilize.
However, as with any weather event, unforeseen activity is possible and likely. It would not be a surprise if a storm or two were able to form out ahead of the main line of convection. If this does happen, and a few storms can form in New England before the arrival of the Cold Front and before the loss of daytime heating, then those storms will have the capability to be quite strong. Again, these few rogue storms are only a possibility and are not as certain as the storms that will effect places to our west.
-Chris
Even after the tropical downpours from what was left of Isaac left our region, we are still stuck with the tropical-like environment in its wake. You have probably noticed, but it is HUMID outside!! Temperatures are only running in the mid 70s, but the dew points are in the mid 60s as well. Making for a very humid environment. What we need to get rid of this air mass is a Cold Front; which is on the way for Saturday Night. But before we are able to experience the cool refreshing air that comes with a Cold Frontal passage, our temperatures and dew points are going to increase. Reason being is that the wind direction ahead of a Cold Front is from the south or southwest; which for us is generally a warm and humid wind direction. So for Friday and Saturday temperatures will be in the low 80s and dew points will be on the rise into the low 70s. Or simply put: HUMID!!! Finally after the front passes offshore early Sunday morning, our wind direction will switch around to out of the northwest and bring with it cooler and drier conditions.
As for how Saturday into Sunday is going to break down, it is as follows:
2 pm: The Cold Front should be located in Central NY State and heavy downpours and thunderstorms will have developed along it. Some storms could be strong. For our region; temperatures will be in the low 80s and dew points will be in the low 70s. This kind of air mass is a fairly unstable one. Which means that if any rogue storms fire ahead of the main line, then they could be quite strong as well.
8 pm: The Cold Front will be located around the MA/NY border and into Southern VT and through Northern NH. Showers and storms will continue to exist right along the front. Some may still be strong. As we lose solar insolation (sunlight), thunderstorm activity should begin to decrease in intensity, but not completely cease to exist. Places further east of the main line will still be fairly unstable, so again any pop up storms ahead of the main batch could be strong.
Overnight: Cold Front moves across New England. Bringing with it heavy rain and embedded thunder. 1-2″ of rain is possible; and as always, higher amounts can not be ruled out in isolated thunderstorms.
Sunday Morning: Cold Front pushes offshore and any left over rain moves away as well. All rain should be gone by noon or a little after. Giving way to a cooler more comfortable air mass; especially for Monday and Tuesday.
7 DAY FORECAST
Tonight: Chance of a shower and storm for Western and Northern New England as storms in New York State move east with time. Patches of fog should develop as we head towards morning. Overnight lows in the upper 60s.
Friday: Fog to start giving way to mostly cloudy conditions. Chance of a scattered shower for most of Southern New England; best chance lies back in Northern Connecticut and Western Mass. Daytime highs in the mid 80s.
Friday Night: Areas of fog develop again. Mostly cloudy skies. Lows in the upper 60s.
Saturday: Warm and HUMID. Morning fog burns off as we watch a Cold Front approach us from the west. Most of the day should be dry for us. Shower and thunderstorm activity should begin to increase around supper time. Rain and storms will last throughout the night. Highs in the low 80s.
Sunday: Morning showers and downpours come to an end as the Cold Front pushed off shore. Very comfortable air mass on the way behind the front. Highs around 75.
Monday: Beautiful. Fall like feel to the air. Highs around 70.
Tuesday: Repeat of Monday. Highs in the upper 60s to near 70.
Wednesday: Warmer. Highs in the mid 70s.
Thursday: Warmer still ahead of our next system. Highs in the upper 70s.
Tropics:
Orange: Amazingly this area of showers and thunderstorms that moved into the Gulf from the Southeastern States is a piece of energy from what was Hurricane Isaac. Given a 40% chance of development by the National Hurricane Center, this disturbance will receive a new name if it does in deed develop into a named system.
Hurricane Leslie: 
Formed from a wave that moved off the African Continent, Hurricane Leslie has been with us for some time now. Leslie is a large system that has been nearly stationary south of Bermuda for a few days. The steering currents around Leslie are very weak, therefore she has not moved much. Eventually though, she will be picked up and will begin to accelerate to the north; impacted the Island of Bermuda as a Hurricane. From there she will continue to accelerate north and will make a pass very close to Newfoundland Canada.
Hurricane Michael: 
Michael is the first Hurricane of the 2012 season to be categorized as a major Hurricane with wind speeds of 115 mph; making him a Category 3 storm. Michael is very far away and is no threat to us and is no threat to any land for about the next week. But he is a good looking cyclone, so here is a satellite still of Michael. 
-Chris
Chris Hampton Weather 