Disc: A generally warm pattern will continue for the time being, with fairly frequent, at least chances, for thunderstorms.  There may be a cooler period to start July, but a lot of that depends on frontal position.

Currently: Low pressure over the Chesapeake Bay could kick off showers and thunderstorms later tonight.  But for the rest of today, expect generally warm and dry wx.

Tonight: The aforementioned low may kick off a round of showers and thunderstorms for the state tonight, probably centered around midnight.  This time, the chances are fairly uniform across the state, and fit into the "scattered" category.  As far as temps, I'll go a couple degs blo guidance, as rainfall shud help bring a little cooler air down from upstairs.  Xpct lows in the low 60s.

Tomorrow: Can't see why SPC has the area in general thunderstorms.  Subsidence should rule the day and this should keep any t-storms hundreds of miles to our W.  As for us, I'd xpct a warm day with moderate levels of humidity.   Guidance looks reasonable, so I just made a regional tweak here and there.  Xpct highs in the mid 80s, w/maybe a few upper 80s along the I 91 corridor.

​Tomorrow Night/Sat: Although the core of the severe weather should remain off to our west and southwest, Saturday looks like a good day for widespread showers and storms.  The first round should come through early in the day with a warm frontal passage, and then the second, possibly containing strong storms, should come through later in the day with a cold front.  I'll go a few degrees cooler than guidance, since there shouldn't be many hrs of full sun and that could definitely throw off high temps.  So look for highs in the low 80s, for the most part.

Long Term (Sun and beyond): A little instability remains during the first part of Sunday, so there is a slight chance for another quick thunderstorm, but Sunday should be largely dry, especially since humidity at all levels should gradually decrease as the day wears on.  With modest cold air advection, I'll go a couple degrees below guidance.  So expect high temps in the mid 80s.

Monday should be a dry day, as we're between systems.  Guidance looks very reasonable, so I'll accept it with a few regional tweaks here and there.  It will still be very warm, but humidity lvls shud be low.    Xpct highs generally in the upper 80s, xcpt a ltl cooler alg the S coast and in the NW Hills.

Most of Tuesday should be dry, as well, but humidity will increase, and some showers and thunderstorms could make it back into the area by nighttime.  Once again, temp guidance looks reasonable, so I'm not planning on making any huge changes to what is in the system.  Highs shud be in the mid 80s, xcpt a few upper 80s along the I 91 corridor.

The last two days of the forecast period, Wednesday and Thursday, depend very highly on the position of a frontal system.  As you might expect at this range, models are not in good agreement and are not showing good continuity from run to run regarding the position and progress of the frontal system.  Therefore, my fcst will be rather "generic".  Suffice it to say, xpct unsettled wx, w/very low confidence in temps.

Given the uncertainty in this period, I also did not stray too much from temperature guidance.  Right now I am thinking highs should be near 80, with maybe some low 80s along I 91 Wed, and 80-85 Thu. 

The GFS continues to want to flood the USA with very hot air in the long range.  We have had warm days, of course, but nothing like what the GFS has been pumping out.  Given the fact that the GFS has done this in the long range since May, I'll take it w/a cup of salt for now.

Taking a graphical look at some systems slated to affect the area this week... I will not post tonight's system, as it is too short term.  So what I will do is I'll post a map for Saturday's cold frontal storms and then a map with the frontal boundary for next Wed.  So first here is Sat's sys.  You can see on this map a large area of hvy rain pointed at CT, if it pans out, of course.

Now here is a map valid Tuesday night.  This model at this time wants the front to be south of the area (Traceable via red 570 line), but it also pops a weak low off the NJ coast, which would enhance and prolong pcpn.  We have a long way to go and low confidence with this.

​

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

​-GP!

A general heat dome will be building across the area.  However, it's what we meteorologists sometimes refer to as a "dirty heat dome"- not  that the heat is contaminated or polluted, but that there will be clouds and it will be hard to find a day where the chance of thunderstorms is zero, so all that could temper the heat.

The main problems with this forecast package will be determining how hot it gets, when thunderstorms will occur, and how high the probabilities are for thunderstorms at any given time.  Of course, I will do my best, but things will likely change, because, as we know, meteorology is not fluid and is constantly changing.

Currently: The old cutoff low extends from near IAD to WV.  High pressure is off Cape Cod.  For our area, this means that the low is close enough to give us clouds, but probably no pcpn, as bands rotate to our S and SW.   Meanwhile, the mean flow will be onshore, so temps get kept in check.

Tonight: With clouds around and warm air advection in progress, I'll stay close to guidance or maybe go a degree or so warmer in the normally warm spots.  This yields lows of 60-65 across the state.  I will not mention any pcpn in the fcst, as any chances of that are across far Wrn portions of the state and should be diminishing in a few hrs.

Tomorrow: After closely examining all available model guidance, I will be limiting any chance of showers and thunderstorms to Western CT, and even there, it will be mostly a slight chance.  In my opinion, the only area worthy of more than a slight chance is the NW Hills.  Because of this, I feel there will be more sun than currently modeled.  As such, I've raised temp guidance a couple degrees.  So xpct highs in the low 80s.  Also, any convection shud be diurnal, w/the greatest chc of any storms to be w/the heating of the day.

Tomorrow Night/Sat: Sat should actually be very similar to Friday, in that the only areas that should really see thunderstorms will be across the west.  However, there will be a bigger chance gradient.  That means that along the coast, even in the W, the chance could be near zero, while there is a pretty good chance north of the Merritt Pkwy, and esp up in the NW hills.  Similar to Fri, once again, I'll add a cpl deg to temp guidance, in deference to the fact that there shud be more sun than modeled.  So xpct highs generally in the 80-85 range, although a few spots in the I 91 corridor could pop an 87 or 88.

Long Term: (Sun and beyond): Right now, my feeling is that thunderstorms will be a bit more widespread for Sunday- something like scattered for much of the state, with scattered to numerous in the Northwest Hills, diminishing to a slight chance east of I 91, and no chance at all along the immediate southeast coast.  I will closely follow guidance temps, but will tweak a little here and there, based on where I have probabilities for storms.  Expect high temps to be around 80 degs most sections.

On Monday, I feel the entire state will see a chance of thunderstorms, but the gradient will be different this time- instead of the East/West gradient we have been seeing, it will be more of a south-north gradient, with only slight chances along the south coast, and scattered to numerous thunderstorms in the north.  I think models could be generating too much cloudiness early in the day and temps will get off to a fast start.  Therefore, xpct highs in the mid to upper 80s, a couple degs above guidance.

Tuesday should be dry during the day.  The best forcing arrives at night.  Many times I wouldn't bother talking about t-storms if we have to wait until night for the best lift to arrive.  However, since it will be hot, I feel we'll get scattered coverage of showers and t-storms at night and possibly lingering into vry ery Wed AM.  The fact that the storms will not arrive until night will allow for plenty of sun, and temps shud respond by getting hot! I'll go a few degs warmer than guidance to try to compensate for trends.  Xpct highs around 90, perhaps even 90-95 around the I 91 hot spots.

Current modeling has slowed way down with any frontal passages for next week.  Based on today's modeling, which is all I can go by, the best chances for storms on Wed will be far W sections, diminishing to no chance at all E of I 91.  With lots of sun, look for a hot one again on Wed, with highs in the low 90s.  I again went 2-5 degs above guidance, because I think guidance may not be capturing the heat as hard as it shud this far out.

Depending on the timing of the frontal passage, there is a possibility of some genuine severe weather either Wednesday or Thursday across the state.  At this time, the timing is highly up in the air, with the possibility even of a Thu morn frontal passage.  That scenario would certainly limit the potential for any svr wx.  At any rate, hot air will not be a pblm.  With storms around and a front approaching, Thu shud at least be a bit cooler, with highs in the mid to upper 80s.  I went fairly close to guidance, w/a few regional tweaks here and there.

Looking into the long range, models have waffled a lot regarding placement of various frontal zones and timing various disturbances.  This would have a big impact on our sensible wx here, with everything from temps to precipitation chances affected.  It is my hunch that there will be more days with storms than without, and that temps and humidity will be normal to above normal for at least a while.

There will be no graphics with this package, due to a cache issue on my end.  The best image anyone can look at in the coming days will be a radar map, to see where storms initiate.

That's all for now! See you next week!

-GP!

Good afternoon from SCW! 

It's hard to believe that we're about halfway through June, and so far, things have been mostly quiet. This pattern will continue, with mostly dry conditions expected through the forecast period. This is the last weekend of spring, and right on cue we're watching increasing signals for heat by the end of the week and official start of summer. Let's dive in!

The image above shows the temperature departure in the northeast so far this month. We have been squarely near normal, but that will likely change by the end of the week. We have also been drier than normal, making this allergy season a bit more rough for some! 
​
Monday-Wednesday
Expect plenty of sun and relatively comfortable temperatures. All week, high pressure is expected to dominate. However, for the first half of the week, the upper level pattern is such that temperatures should be held in check by a more amplified pattern that puts the bulk of the heat over the Midwest. Some locations in the upper Midwest may be approaching the upper 90s during this part of the week! 

Here's the latest GFS above. Note how the ridging is centered over the central US during the early to middle part of the week, with a cutoff low in the south. That should keep our temperatures seasonable if not a touch below normal. The first half of the week should be quiet. Notice how the ridge and higher heights shift towards the region by the latter half of the week. That's where we begin to see things look and feel more summery. 

Thursday-Friday
The latter half of the workweek looks fine as well, but we will see slightly higher chances of some stray showers. Despite the increasing precipitation chances, both days look partly to mostly sunny. Temperatures and humidity will be on the rise, and we could be seeing inland temperatures in the upper 80s to low 90s by Friday, setting the stage for what may be our first heat wave. 

Saturday-Sunday
To recap, a heat wave is defined as three consecutive days of 90 or higher temperatures. We may get there for the first time this year on Friday-Sunday, but I think the odds right now are 50/50.

Things depend heavily on the placement and progression of a cold front. Saturday and Sunday look hot and humid, but there could be some popup showers and storms that would keep temperatures down. Currently, it looks like the front may wait for later Sunday or early Monday, which would increase the chances of heat building over the region, but we'll keep watching to better fine tune the timing of the front. 

Above is the European ensemble for the end of the week and weekend. Note that the 850mb temperature anomalies center themselves over the region before the cold front pushes into the region. It doesn't necessarily mean we'll reach our heating potential, but it is a fairly robust signal for a summery start to official summer! 

The Dailies
Monday: Mostly sunny. Highs in the low to mid 70s. 

Tuesday: Mostly sunny. Highs in the upper 70s to low 80s. 

Wednesday: Mostly sunny. Highs in the low to mid 80s inland and upper 70s to low 80s at the shoreline. 

Thursday: Mostly sunny with increasing humidity. Highs in the mid 80s inland and upper 70s to low 80s at the shoreline.  

Friday: Mostly sunny. Hot and humid inland. Highs in the upper 80s to low 90s inland with highs in the low to mid 80s at the shoreline. Chance of showers 20%.

Saturday: Partly cloudy. Hot and humid. Highs in the upper 80s to low 90s inland with highs in the mid to upper 80s at the shoreline. Chance of showers 20%.

Sunday: Partly cloudy with a chance of showers and thunderstorms late. Hot and humid. Highs in the upper 80s to low 90s inland with highs in the mid to upper 80s at the shoreline. Chance of rain 50%.

A​s 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.

One of these days I will get to that tropical outlook! Thank you for reading SCW. 

-DB​ 

This week's forecast, aside from tonight into tomorrow, is not very straightforward at all, as it hinges upon the evolution of a cutoff low that will cutoff somewhere over the Eastern United States and exactly where will have drastic differences in our weather.  Unfortunately, models are not in very good agreement.

Currently: The first focus of this forecast is a cutoff low, currently over the Lehigh Valley.  This will be the focal point for a round of showers and t-storms later on.

Mesoscale Update: A Flash Flood Warning has just been issued for the Eastern Boros of NYC, as well as adjoining Western Long Island.  This area of heavy showers and t-storms should head into Wrn and Central CT in the next couple hours.

Rest of today/tonight: An area of showers and thunderstorms should move through the state beginning soon.  Any t-storms could contain heavy downpours and strong & gusty winds, but we are not expecting an outbreak of severe wx.  All the activity should be outta the state, even the far Ern sxns, by midnite.  As for temps, guidance will be closely followed, since I see no reason not to.  So xpct low temps of 60-65.

Tomorrow: Warm but much drier behind the cold front.  With full sun and a downsloping component to the wind, I have decided to go a couple degrees above guidance.  So expect high temps of 80-85.

Tomorrow Night/Sat: Confidence in the overall forecast begins decreasing here, but Saturday will probably be a good day, weatherwise.   I'm not going to mention any precipitation for Sat, but it is interesting to note that the NBM gets measurable right up to about NYC.  So I suspect it could be cloudier than current guidance advertises, and I'll lean fcst that way.  Because of this, I'll go just a smidge under guidance temps.  Highs shud be in the mid 70s.

Long Term: I have, quite possibly, the lowest confidence in the long term forecast than I've had in recent memory.  Models had been trending north and wetter with the cutoff low, then the 12Z GFS came out and went way south, but still eventually gets some moisture up this far, but we're talking Thu instead of Sun if it's right.  When I went to check the 12Z GGEM, it is not avail on any sites I use.  The 12Z ECMWF is not ready for another half hr.  I might updt this sxn when the ECWMF runs.  But for now, the fcst will be based on an examination of the GFS w/NBM guidance, which incorporates other guidance suites and ens guidance.

Glancing at the NBM, it actually seems close to the GFS.  So for now, I'll keep measurable precipitation S of the state until Thursday.  However, it should be noted, esp for the S coast, that measurable pcpn is not far away any given day and a small change in modeling would result in a much rainier fcst.  Either way, ti shud be a cloudy and coolish week, and obviously much cooler if the cutoff low is a bit further N.

Starting with Sunday, I'll go close to guidance, maybe a tweak up here and there.  Expect highs of 70-75.

For Monday, guidance inches ever so closer with precipitation.  I think it may not be far enough N.  Based on this, a strong onshore flow, and overcast skies whether it rains or not, I'll go a few degs below guidance.  So look for highs only around 70.

For Tuesday, similar to Monday, I have a sneaky suspicion that steadier precipitation may creep in.  Once again, I'll go a few degs below guidance.  Xpct similar temps to those of Mon, maybe a deg warmer.

For Wednesday, even the GFS has precipitation knocking on the door.  So I'll bring at least a little precip into most of the state, as my methodology this entire fcst pckg has been to go about 50 miles N of where the GFS has it.  Could even be a brief tstorm along the S coast.  Again I'll go under guidance by a few degs.  Xpct high temps in the low 70s.

For Thursday, nearly all guidance has measurable precipitation getting into the state, although the precipitation mode shifts from stratiform to convective, which would mean "less steady" precipitation.  With the lack of confidence in the overall details of this part of the fcst, it would be futile to try to time when this would occur.  But right now, given that most modeling has this happening during the day, I'll lower guidance temps.  So xpct highs in the mid 70s.

Update on the 12Z ECMWF: It is in and is even drier than the GFS, not even getting precipitation in here Thursday.  It's a cloudy, cool, onshore flow look, but with no precip.  There are a few showers Tues along the NY/PA border, so we'll see if we can squeeze anything out of that.  It's a fluid situation, and could easily chg agn next run, but this is another reflection of being stuck in a repetitive pattern w/o much chg in sight.

Looking into the longer range, the GFS once again tries to produce big heat beginning around day 8-9.  I would caution against that, since it seems to never move up in time.  We'll have our very warm to hot days on occasion, but I wouldn't go predicting a big hot pattern until I see more evidence of it than a day 9 GFS map.

Now, let's take a graphical look at some of the systems slated to affect our area in the coming week.  I really don't know what to post here.  Tonight's sys is extremely near-term now and the cutoff is going to be meandering all week.  I guess I'll post a GFS map and an ECMWF map for comparison purposes.

In this first image, the GFS, valid next Thursday, shows precipitation being strung out between two highs and a very weak low, what is left of our cutoff, near the Delmarva peninsula.

​

On the next image, the ECWMF has the low a bit stronger, but much further south, down by Hatteras.  As a result, the blob of precip that the GFS has affecting our area is down off the Delmarva.  Meteorologically, it's curious that the high posn on the ECMWF is actually more conducive of bringing the low further N, yet the GFS has the low further N.  This illustrates my lack of confidence durg this pd quite well, and I am fairly confident tda/s soln is not the final one.

​

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

-GP!

We'll see more unsettled weather across the state the next few days, until a cold front finally clears the area on Saturday.  Although widespread severe weather does not appear likely, any t-storms can strengthen and produce gusty winds, small hail, and heavy downpours.

Currently: Two main features on the map this afternoon: A stationary front straddling basically Interstate 90.  Along and S of that front is the focal point for t-storms.  TD Cristobal near the Mexico/Guatemala border, expected to move back N into the GOMEX could impact our wx further down the road.

Before I begin the actual discussion, I wanted to start with a quick modeling note, directed at my fellow meteorologists, professional forecasters, cohorts on this site, etc.  I have been using the NBM guidance as a replacement for unreliable MOS products.  And while it is better, esp with temps, it has its flaws, such as almost always underdoing wind, and always underdoing pcpn in the xtndd range.  There is a new NBM product, the experimental products (scroll further down in the text prods menu).  I have been tinkering w/it and I really like what I see.  Those two biases are gone.  I do not know the official reason or how these algorithms are officially calculated, but my best guess is that the older NBM versions incorporated too much of the "bad" ens prods.  For example, when using ens-based guidance, you are genly supposed to delete the outliers.  I have a feeling the old NBM did not do that, while the new NBM does that better.  Now on to the disco:

So, starting out with the rest of today.... we can probably get away with keeping the rest of the day dry, as it appears any convection should hold off until later tonight.  But I can't totally rule out a sprinkle here or there, as the air mass is still conditionally unstable.  High temps probably won't get as high as the warmest guidance numbers.  It seems like so far this late spring into summer, nature has found any was possible to temper high temps, whether it's a band of clouds that coincides with max heating, a sudden onshore breeze for an hr or two, a freak sprinkle, nature has seemed to laugh at us and keep temps down any way possible each day.  This is a product of the pattern and I will not ignore it until I see clearly that the pattern has broken.

Now for tonight, the highest chance of storms should be centered around midnight, give or take a few hours.  Since the storms will be moving SW-NE and exhibiting a weakening trend, the highest chance of storms should be across SW CT.  As far as temps, guidance is in very good agreement, so I don't see any reason to make any chgs.  Look for lows in the low 60s.

Tomorrow: With the frontal boundary still in the area, it would be hard to forecast a completely dry day tomorrow.  That said, once again, the highest chance of storms will be the further S you go.  It will be warm and humid once again, and there should be more clouds than today.  Therefore, guidance looks quite a bit too warm and I will be subtracting at least 5 degs from it.  There is a chc of tstorms at just about any time, but the best chc looks to be late in the day into the eve.  As for temps, look for highs to be in the mid 70s.

Tomorrow night/Sat: We'll gradually dry out the atmosphere, but there is still the chance for showers and thunderstorms on Saturday until the actual cold front goes through.  Once again, areas further south will have better chances of thunderstorms, and activity should be concentrated on late day and early evening.  As for temps, I will go a couple deg warmer than guidance, since there should be more sun on Sat and a good warm surge ahead of the cold front.  Look for highs in the low to mid 80s.

Long Term (Sun-Thu): The first half of the long term period is sunny and pleasantly warm.  As they used to say in the old days of wx forecasting "Wx nil" translated- no weather.  I generally went close to guidance for temps, but a couple degrees higher on Tuesday, as I think modeling is not capturing the warm surge well yet.  (High press moves offshore and sets up return flow of warmer air).  So look for highs in the mid 70s Sun and Mon and then approaching 80 Tue.

The forecast for Wednesday and Thursday becomes a lot more complicated.  A strong cold front will approach from the west.  At about the same time, whatever is left of Cristobal will probably become absorbed into the cold front.  Whether this just enhances rainfall or actually produces its own storm w/heavy rain and high winds is yet to be determined.  The 12Z GFS is completely dry and is being ignored for several reasons.  First, it is the only run to do that in many runs.  Second, nearly all other op guidance and ens guidance disagrees with it.  Finally, it moves Cristobal back into the mtns of Guatemala and Honduras and destroys the sys.  It is the only op model that still insists on doing so, so it is being ignored for the time being.  

Assuming that Wednesday is mostly dry and any rain holds off until nighttime, guidance temperatures look Ok and will be accepted for now.  So expect highs in the upper 70s.   For Thu's temps, if I assume it will be raining most of the time, I'll go a couple degs lower than guidance.  So I'll call for highs of 70-75.

Looking into the long range, I again have to ignore the GFS.  The NBM, ensembles, and basically all other operational models disagree with what the 12Z GFS is spitting out, which would be a warm to hot and dry pattern.  For some reason, the GFS likes to "run very hot" every day at 12Z, while most of the other runs never do that.  It hasn't been right yet.  I think some of today's flaws could be tied to what it does with Cristobal in the short term.  At any rate, most other guidance shows a trough in the east, with a pattern that favors below to much below norm temps and even potential east coast storminess.  NBM showing another high QPF event Jun 12-13, so the GFS is going to be ignored until it proves itself right.

Now, let's take a look at some systems to affect the area in the coming days.  Due to the unsettled weather in the short term, combined with uncertainty in the long term, we'll stick with the t-storm chances for tonight and tomorrow.  First, let's look at this map, which is valid tonite at midnite.  Vry hvy rain is over NE NJ and SE NY, but you can already see how it is dying as it enters CT.  This is why chcs are so much higher over SW CT than NE CT.

The next map, valid midday tomorrow, shows more thunderstorms.  You can see the highest concentration of storms is down by Philly, and once again chances for storms diminish the further N you head.  

​

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

​-GP!