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...FINALLY SOLID SIGNS OF THE WARM TO HOT WEATHER BREAKING IN THE LONGER RANGE...

9/26/2019

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​Disc: We will be warm to hot for about another week, then finally it looks like the pattern will snap with more appropriate weather for October moving in.

Currently: A cold front was located from Western PA into adjacent New York state.  This cold front has triggered some showers out ahead of it.  As these showers encounter warmer and more humid air, some thunderstorms may develop.  A few thunderstorms may even be strong, especially across the eastern and southern portions of the state, where higher moisture content resides.

Tonight: As mentioned, the first order of business will be tracking some showers and thunderstorms as they track across the state.  We're not really looking for an outbreak of severe thunderstorms.  However, there could be a few strong thunderstorms embedded within the line.  Now for later in the night, I do think the showers and storms will leave the state early enough to allow for some clearing skies later.  Model statistical guidance has run too warm at night about 9 out of the last 10 nights.  So I'll shave a degree or two off guidance across the board.  Expect lows ranging from the mid 40s in the NW hills to the mid 50s along the south coast.

Tomorrow: Model guidance is in reasonable agreement.  With near full sun, I'll go with the warmer GFS guidance.  High temperatures should be within a few degrees of 75, cooler north, and warmer south.

Tomorrow night/Sat: High pressure moves offshore, so expect the humidity to gradually increase.  Another cold front approaches later Saturday and could trigger more showers and thunderstorms.  This time expect most of the precipitation to wait until nighttime.  Although with a warm and humid air mass in place and a front approaching, there is at least a slight chance that a storm gets in during the daylight hours, especially western sections.  Once again, will run with the warmer GFS guidance set.  With the higher humidity and more of a southerly flow, temperatures across the state should be more uniform, generally ranging in the mid to upper 70s.

​Long Term (getting into next week): Not much in the way of precipitation is expected for the bulk of the long term, until probably later Wednesday into most of the day on Thursday.  That is when the wheels get set in motion for a large-scale pattern alteration that will bring autumn to the northeastern United States.

From Sunday to Wednesday, no major changes were made to the existing temperature guidance.  I only made minor tweaks here and there to account for local climate variables.  So, high temperatures from Sunday through Wednesday look like this:

Sunday: Mid 705
Monday: near 70, except warmer in the I 91 corridor.
Tuesday: Near 80, except cooler in the NW hills.
Wednesday: low 80s, except cooler in the NW hills.

Then on Thursday, cold air rushes into the region.  Models tend to underdo air mass changes (of any kind) at a D+7 lead time, so I went 3-5 degrees cooler than guidance all areas as a good start.  High temperatures on Thursday should only be within a few degrees of 60,  from north to south.

Ahead of this strong cold front, showers and thunderstorms will be possible, if not probable, beginning later Wednesday.  As the front clears the area, it could take on more of an "anafront" type characteristic, which means showers (but not thunderstorms, as the air mass will be more stable) should linger behind the front for most of the day on Thursday.

Looking into the long range, the pattern definitely looks like more of an autumnal pattern vs the extended summer pattern we've been having,  Look for pleasantly cool days and cool to chilly nights.  

Now, let's look at some of the weather systems slated to affect the area in the coming week.  This time, I'll show you just high temperature maps for Wednesday and Thursday, so you can get an idea of the change that is coming!  Here's Wednesday.  Notice how 80s cover just about the entire state, as I outlooked, with the only exception possibly being the NW hills.  

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Now the next map is Thursday (next week).  Note how highs across most of the state are in the 50s, except along the south coast, where a few 60s still show up.  80s have essentially disappeared from the Eastern US! It's going to be a big change!

Anyway, that's all for now! See you again next week!

​-GP!
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...GENERALLY ABOVE NORMAL TEMPERATURE PATTERN TO CONTINUE FOR QUITE SOME TIME...

9/18/2019

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For the next couple weeks, a large ridge should park itself over the Eastern US.  This should translate into above normal to much above normal temperatures.  However, I would exercise a little bit of caution with that, since the chilly air that lasts roughly from now to Friday morning was not really picked up in the long range and there is cold air to tap in Canada.

Currently: Cool high pressure over Ern Quebec dominates our weather.

Tonight: With good radiatonal cooling conditions expected and fresh cold air advection, I'll go a touch lower than all available guidance.  This should effectively kill off most of the mosquitoes in the state (unless they seek shelter).  Look for lows mainly in the 40s, but 30s should be widespread north of I 84.

Tomorrow: With plenty of sun, low humidity, and soil moisture lower than it has been all summer I"ll go warmer than guidance.  A beautiful day, after a chilly morning, is in store, with highs generally 70 to 75.

Tomorrow Night/Fri: We'll continue to see a trend of large diurnal ranges, or differences between daily low and high temperatures.  As high pressure shifts offshore, look for a warmer day.  There has been a downward trend with Thursday night's lows, and this has resulted in a tick or two downward with Friday's highs, since days are now only 12 hours long.  Guidance is in fairly good agreement, but in a nod to trends, I'll shave a degree or so off guidance high temperatures.  So expect high temperatures generally in the mid to upper 70s, but a few degrees cooler in the NW Hills.

Long Term (the weekend and beyond): For now, the only active period in the long term looks to be from Monday afternoon until Tuesday morning, as a slow-moving cold front tries to move into the Bermuda Ridge.  Models are trending wetter with this feature and I would not be surprised if this turns into a "multiple rounds of thunderstorms with heavy downpours" type of event, like we've seen most of this summer.  The pattern fits the same type of events we've had earlier in the summer, and with the ridge and temperatures (as well as humidity levels) modeled to be much higher than they should be this time of year, why not?

But before we get there, we have a very warm and tranquil weekend coming up.  As far as temperatures through the long term period, I did not make many changes to guidance, other than tweaking here and there for local influences.  The only exception to the rule is Monday, where models have trended cloudier and wetter, and are also hinting at the potential for onshore flow.   Therefore, MOS guidance looks quite unrealistic, and I chopped off 5 to 8 degrees from advertised guidance.  So the dailies in the long term look something like this:

Saturday and Sunday: Sunny.  Highs in the low 80s Saturday and 80 to 85 Sunday.  One or two spots in the I 91 corridor could actually hit the upper 80s on Sunday.

Monday: Increasing clouds with showers and thunderstorms late.  Highs around 70.

Tuesday and Wednesday: After a chance of a shower or a thunderstorm Tuesday morning, clearing. Still above normal temperatures, but not quite as warm, with highs in the mid to upper 70s on Tuesday and low 70s on Wednesday.  An onshore flow could make it cooler along the south coast Wednesday.

Looking into the long range, temperatures really look above, to even much above normal, as far as the eye can see.  As I stated in the opener, the only fly in the ointment would be a backdoor cold front which would aid in the cold air just to the north of the border seeping southward.  Models have not handled that well this month at all, so it is a distinct possibility.  There are some hints that the pattern will re-orient itself in a big way before the middle of October, which would result in a major pattern change across the US.  This has the looks of a pattern that could flip like a switch, and not be a gradual step down.

Now, let's take a look at weather systems slated to affect the area this week.  Since we only have one real system to speak of, I decided to post GFS low temperatures for tonight and Monday evening's system.  Looking at the GFS temperature map here, you can see that low temperatures (which are 2 degrees lower than this map, because I was unable to actually retrieve the low temperature map) are in the 40s throughout the state.  Subtracting for climatology on radiative nights means that anyone north of I 84 can easily be in the 30s.

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The next map is valid Monday night at midnight.  You can see showers and thunderstorms ongoing across the state and quite a bit more to come, as the cold front is only slowly trudging southeastward.

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Forecaster Discussion--9/15/19

9/15/2019

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Good evening from SCW. 

Halfway through September! Time continues to fly as we are just a few days away now from the official start of Fall. We're at the time of year where even above normal temperatures like today can feel great. The week ahead looks wonderful, with a brief return to cooler conditions before we warm up again by the next weekend. Let's jump in! 
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A GOES-16 look at Tropical Storm Humberto, which is gradually organizing and should intensify into our third hurricane of the topical Atlantic season tonight. Humberto's long term track is a bit uncertain, but it is unlikely at this point to impact New England. 

Monday
Tomorrow is likely to be our "worst" day of the week, as a weak area of low pressure approaches the region. The day looks to be mostly dry, but there will be shower chances and cloudy conditions. Tomorrow looks to be a touch cooler than today. 

Tuesday-Friday
This'll be a short forecast, because the rest of the week looks fantastic. A ridge of high pressure will develop and traverse the region, and that means we will see wonderful days and crisp, cool evenings. Like GP said in his earlier forecast, the general trend is warmer than normal, but this is one of those times where we see cooler than normal conditions for a brief period. Highs will struggle to reach 70 by the middle of the week with lows in the 40s! It'll be a taste of fall for sure. 
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Look at that cool snap! Here's the GFS Ensemble showing a cool down during the week, followed by a warm up by the weekend. 

Saturday-Sunday
We will be watching what Humberto eventually does (especially when it comes to wave height and rip current risk), but all indications are that the weekend will be beautiful and warmer than normal. 

The Dailies
Monday: Mostly cloudy with a chance of showers. Highs in the low to mid 70s. Chance of rain 40%. 

Tuesday: Mostly sunny and cooler. Highs in the low 70s.

Wednesday: Mostly sunny. Highs in the mid to upper 60s.  

Thursday: Mostly sunny. Highs in the upper 60s to low 70s. 

Friday: Mostly sunny and warmer. Highs in the mid to upper 70s. 

Saturday: Partly sunny and warm. Highs in the upper 70s to low 80s. 

Sunday: Partly sunny and warm. Highs in the upper 70s to low 80s. ​

As always, please like, share, and interact with us on our social media--on Facebook to share our discussions, and follow us on Twitter @southernctwx to retweet our posts. Hit the buttons below to join.

Thank you for reading SCW. 

-DB​
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...GENERALLY ABOVE NORMAL TEMPERATURE PATTERN TO CONTINUE, BIGGEST QUESTIONS ARE WHERE THE FRONTAL BOUNDAR(IES) SET UP...

9/12/2019

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TA generally above normal temperature regime will set up for the next 2-3 weeks or so.  But there will be breaks.  There is a lot of cold air in Canada, and pieces of this will break off from time to time.  But all in all, a warmer than normal temperature regime is in place.  There will be some difficulty forecasting the position of the frontal boundar(ies) and the associated temperatures, as a result.

Currently: Low pressure along a frontal boundary is right over NYC, so the front has cleared the entire area.  High pressure over Ontario will bring cooler and drier weather to the state for the next couple days.

Tonight: Will keep the forecast dry, since the front has already cleared the state.  However, the front is not far away, and is not moving very quickly, so I don't expect skies to clear.  For that reason, I do not expect much radiational cooling.  Therefore, I'll go a couple degrees warmer than temperature guidance.  Low temperatures should generally be within a couple degrees of 55 degrees.

Tomorrow: A beautiful autumnal day. Plenty of sun, and an onshore, but light, flow.  Because the onshore flow is not strong and the sun should win out over the onshore flow, I'll go a degre or two warmer than guidance for tomorrow.  Expect high temperatures around 70 degrees.

​Tomorrow Night/Sat: We should be able to squeak out a pretty good day on Saturday.  The same front that went through today will eventually approach as a warm front.  However, any precipitation associated with this feature should hold off until later at night, so the day should turn out fine.  However, clouds well ahead of any precipitation should get in here quite early in the day.  Also, SSE flow should become a bit stronger.  With the combination of more clouds and a stronger onshore flow, I'll go a degree or two lower than guidance for Saturday.  High temperatures should be near, or maybe just above 70.

Long Term (Sun-Thu:) Sunday's forecast is not as clear cut as it appeared to be earlier.  The warm front probably will not just blast through the state.  Even so, most of the state should see precipitation end by around dawn.  However, in eastern CT, roughly east of I 91 or so, isolated showers or even a thunderstorm are possible throughout the day on Sunday.  As for temperatures, for now, we'll assume the front clears the entire state by early afternoon, so as to not really mess up and flip flop our forecast.  Guidance temperatures are more or less accepted, but I may go just a degree higher, since gridded data is significantly higher.  High temperatures should be around 80 degrees, but it is possible some sections in the I 91 corridor get a bit warmer than that.

The rest of the long term should be fairly quiet.  Monday is the hot day of the long term.  Later Monday night, a cold front will move through and bring a much cooler air mass into the region.  However, there is not much forcing associated with that front, so for now, will continue with a dry forecast.  A warm front approaches on Wednesday.  Warm fronts tend to produce more precipitation in this region than cold fronts this time of year.  So I'll add a slight chance for showers and areas of drizzle on Wednesday.  As for temperatures, guidance looks very good through the period, so only very minor adjustments were made.

Speaking of temperatures, these are the temperatures I expect through the rest of the long term period.

Monday: Around 80, except cooler along the south coast.
Tuesday: low 70s
Wednesday: near 70, except a bit warmer in the I 91 corridor
Thursday: mid 70s, perhaps cooler in the NW hills.

Looking into the long range,. generally above to much above normal temperatures should persist during this period.  The danger of a sustained truly warm pattern is the cold air over adjoining eastern Canada, and the associated potential for a back door front.  There is also potential for high pressure to anchor NE of the area and produce more of an onshore flow than currently modeled.  However, the upper air pattern certainly looks like a warm one heading into late September in Southern New England.  There are some hints that the pattern may begin to make meaningful changes toward the end of the month or beginning of October, when bigger pieces of that Canadian air start breaking off and heading into our region.

Now, let's take a look graphically at a couple systems slated to affect the region this week.  There really isn't all that much to show you right now, but we'll take a look at two warm fronts- one modeled to go through Sunday morning and the next one slated to go through some time on Wednesday.  This map is valid very early Sunday morning and shows precipitation advancing into CT. There is a very weak low, verbatim, on the map just east of ACY.  However, a low this weak can be a function of the computer algorithm and not real, since the "low" is actually higher pressure than mean SLP.

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Next, let's look at the warm front slated to go through Wednesday.  If you look at this map, a few sprinkles are noted over the NYC metro area Wednesday afternoon.  With a warm front, precipitation can always be a bit heavier than that, so I added a slight chance of showers to the forecast.
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...WATCHING SEVERE THUNDERSTORMS TODAY AND DORIAN FOR FRIDAY AND SATURDAY...

9/4/2019

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 A cold front approaches the area late today, This will be the trigger for potentially severe thunderstorms.  For this reason, the Storm Prediction Center has issued a Severe Thunderstorm Watch for the entire state.  Hurricane Dorian is currently located, per NHC, about 100 mi E of Jacksonville, FL, and moving NNW,  There are still a few potential scenarios for this storm, with regards to how it effects our state.  The growing consensus, however, is that the heaviest effects should be over the Eastern half of the state.

For tonight, severe thunderstorms are possible the first half of the night.  Please refer to products from the National Weather Service for up to date information.  The offices that cover this state are OKX (NYC/LI office) for the southern half, BOX (Boston/SNE) for most of the Northern half, and ALY (Albany/Hudson Valley) for the NW Hills.  As far as temperatures, low temps really depend on when skies clear.  Since I do not have a ton of confidence either way, I'll split the guidance, and go for lows ranging from the mid 50s to lower 60s.

For tomorrow, we're in between systems.  I'll go solidly higher than guidance, since we have a high launch point, and I really don't buy the models that show lots of clouds.  Any clouds would be from Dorian, probably be of the high variety, and not arrive until late in the day.  So they won't have much of an effect on temperatures.  Highs should be in the mid to upper 70s.

Tomorrow Night/Fri: A lot of this forecast depends on the future track of Dorian and also its potential interaction with a trough.  There are three distinct scenarios at play here.  The first is Dorian passes well east of the area, with no apparent effects at all. For now, that scenario is being dismissed, especially for Eastern CT, since Dorian is growing in size, and for a complete miss, it would have to track well to the east, which does not look plausible right now.  The second scenario is Dorian misses east, but a PRE (predecessor rainfall event) sets up and gives the state some rain, possibly heavy East.  The final scenario is Dorian fully phases with the trough, strengthening him and pulling him further west, with obviously, much stronger impacts for the entire state.  I do not want to really go that route yet, since it would take perfect timing.  However, seeing what the latest ECMWF model does really does give me pause (that this could be a viable solution).  For now, I'll go with scenario 2 and incorporate a little of Scenario 3, pretty much splitting the difference between the ECMWF and GFS models.  This gives the entire state rain later Friday into early Saturday morning, with potentially heavy rain in Eastern CT.  I'll also add wind gusts to 40 MPH for Western CT and 50 MPH for Eastern CT for now.  It is hard to imagine not needing at least a wind advisory for at least the Eastern third of the state .  For temperatures, I'll go a couple degrees below guidance, especially below the GFS, since I think that model is not showing enough rain.  Expect high temperatures generally in the upper 60s.

After whatever Dorian does to the state finishes early Saturday, expect a long stretch of nice and calm weather across the state.  There are a couple slight chances of precipitation early in the week, as a series of very weak cyclones rotate across the Western Atlc.  This could create enough of a marine layer to produce a few periods of light rain or drizzle.  But for the moment, chances remain low enough to not include in the forecast.  

As for temperatures, for most days in the extended, I stayed fairly close to guidance, with just a tweak here or there.  The only exceptions being Monday and Wednesday.  I went cooler than guidance both days, in fact, significantly cooler for Wednesday.  On these two days, gridded data is showing strong maritime flow, yet the statistical guidance seems to not be picking up on it.  So here are the ideas for temperatures in the long term:

Saturday: mid 70s
Sunday: mid 70s, but cooler NW hills and South coast.
​Monday: 70 to 75.
Tuesday: mid 70s, but cooler NW hills and south coast.
Wednesday: near 70, except warmer in the I 91 corridor.

In the long range, some of the modeling is hinting at a return to the pattern we've had most of the summer, as fronts buck up against a building Atlc ridge.  If that happens, expect a return to warmer and stormier than normal weather, at least for several days.

Now, let's look at some of the systems slated to affect our region in the coming days.  First, we'll look at tonight's cold front.  Then we'll look at Hurricane Dorian, and what the ECMWF model tries to do with it.
Regarding tonight's cold front, you can see that basically all of New England gets at least some rain.  Radar watching will determine who gets the biggest storms.

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Finally, regarding Dorian, if this ECMWF map verifies, much more intense affects would be felt across the state, including much gustier winds behind the storm on Saturday.  I am NOT forecasting this (yet), but it certainly is something worth watching.

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Anyway, that's all for now! I'll see you next week!

​-GP!
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