Disc: The quiet, beautiful wx pattern this past week will come to a slow end across the area as a more active, changeable pattern begins to take hold.
Currently: Not much going on attm. High pressure located over NYC metro keeping nice wx across the area. This high pressure also extends NEward into the Canadian Maritimes.
Tonight: Clouds should increase, as should onshore flow. For that reason, have gone just a smidge above guidance. Lows mostly 40-45, except a touch warmer near urban centers and along the S coast.
Tomorrow: First off, I have gone just a smidge below temp guidance, due to cloud cover and onshore flow. It will be a largely gray day, but the high pressure to our NE should probably keep any pcpn to our SW. A sprinkle making it here is not totally out of the question, but has been kept out of the fcst, due to very low probs in the guidance. In addition, coastal drizzle is not out of the question, but that generally becomes more of a nowcast feature. It should be noted that NAM guidance hints at just that, and hints that there could be some drizzle and fog along the immediate coast. The NAM has it for the entire S coast. Since the NAM tends to overdo this, I'll mention just in SE CT. As for temps, they should generally max in the low 60s. Inland areas will be considerably warmer than the S coast.
Tomorrow Night/Sat: Once again, the theme will be cloudy, but keeping the precip SW of our state. In fact, the precip may recede even a bit more to the SW, temporarily. This may allow for a few breaks in the clouds. Should breaks become more numerous than I am forecasting, then temps will be too cool in this fcst. My professional opinion is that marine flow will remain entrenched. Thus, I have gone on the cloudier side of things and taken a smidge off temp guidance, which yields a general similar situation to that of Friday. Low level moisture content appears a bit lower, however, so chances of drizzle and fog are lower.
Long Term (Sun and beyond): The wx picture turns a lot more complicated here. First, the easy part. All models agree on a pretty good slug of overrunning rain very late Sat night to about midday Sun. So that is in the fcst. After that, a warm front will attempt to move north. Some earlier model runs pushed this warm front all the way up to I 84. I had a feeling that was probably too far north, as warm fronts don't like to just blast thru this time of yr. Now models have kept the warm front SW of NYC. Therefore, I will fcst similar temps to the past two days, once again going a smidge under guidance. It is not totally impossible for models to go back north, which would render this fcst way too cool. In addition, those who get into the warm sector could see a round of strong t-storms later in the day Sun. For now, I am keeping all of that from NYC S & W. Therefore, our area should be cloudy and cool, but dry, after the morning rains.
The next model issue is for Mon. Some models develop a weak coastal low off the NJ coast, which would "re"increase rain chances later Sun night into at least the first part of Mon. Latest guidance is trying to develop a high pressure lobe into Central New Eng. If that happens, it would dramatically lower chances of rain, esp for NE CT. I want to avoid flip-flopping the fcst too much. Therefore, I envision POPs being layered something like low-end likely in SW CT, to slight chance in NE CT, w/adjustments, of course, being possible. One thing I am fairly confident about is the coastal low will be close enough to keep us cloudy all day, and with cold high pressure to our N/NE and a cool N/NE flow, guidance appears way too warm. I have gone ahead and subtracted a good 8 deg or so from current guidance. Expect highs only around 50 on Mon!
Tue looks to be a bit interesting, as well. Skies do look to clear, as the coastal low pulls away. However, an upper level low will spin into the area. Convective temps are very low on modeled soundings. Therefore, there is a chance for showers and t-storms to develop with at least scattered coverage in the afternoon. Guidance temps appear reasonable, so highs should be in the low 60s.
For now, Wed looks like it could turn out to be the nicest day of the week, as models have us in between upper level lobes. If this is true, sunny and pleasant w/guidance temps generally accepted, and highs turn out in the low 60s.
On Thu, another upper level low approaches. Convective temps look even lower, and a cold front will also approach. With all this going on, I have trimmed a few deg off guidance, and I would only expect highs in the mid to upper 50s. As the upper level low approaches, isolated to scattered showers and t-storms should fire. There is the potential for sleet or small hail to mix in, esp the further N you go with very cool upper levels.
The long range looks to feature generally below normal temps. There is a pretty strong signal for a coastal low in the 4/19-20 time frame. There could even be p-typ issues for the highest elevations if today's modeling is correct! But that's way out and for much later shifts to evaluate.
Now, let's look at some graphical interpretations of wx systems that will affect the area in the coming week. First, let's start with Sun Morn's overrunning rain. This map, valid dawn on Sun, clearly shows lots of rain over the state, with quite a bit more to go.
Currently: Not much going on attm. High pressure located over NYC metro keeping nice wx across the area. This high pressure also extends NEward into the Canadian Maritimes.
Tonight: Clouds should increase, as should onshore flow. For that reason, have gone just a smidge above guidance. Lows mostly 40-45, except a touch warmer near urban centers and along the S coast.
Tomorrow: First off, I have gone just a smidge below temp guidance, due to cloud cover and onshore flow. It will be a largely gray day, but the high pressure to our NE should probably keep any pcpn to our SW. A sprinkle making it here is not totally out of the question, but has been kept out of the fcst, due to very low probs in the guidance. In addition, coastal drizzle is not out of the question, but that generally becomes more of a nowcast feature. It should be noted that NAM guidance hints at just that, and hints that there could be some drizzle and fog along the immediate coast. The NAM has it for the entire S coast. Since the NAM tends to overdo this, I'll mention just in SE CT. As for temps, they should generally max in the low 60s. Inland areas will be considerably warmer than the S coast.
Tomorrow Night/Sat: Once again, the theme will be cloudy, but keeping the precip SW of our state. In fact, the precip may recede even a bit more to the SW, temporarily. This may allow for a few breaks in the clouds. Should breaks become more numerous than I am forecasting, then temps will be too cool in this fcst. My professional opinion is that marine flow will remain entrenched. Thus, I have gone on the cloudier side of things and taken a smidge off temp guidance, which yields a general similar situation to that of Friday. Low level moisture content appears a bit lower, however, so chances of drizzle and fog are lower.
Long Term (Sun and beyond): The wx picture turns a lot more complicated here. First, the easy part. All models agree on a pretty good slug of overrunning rain very late Sat night to about midday Sun. So that is in the fcst. After that, a warm front will attempt to move north. Some earlier model runs pushed this warm front all the way up to I 84. I had a feeling that was probably too far north, as warm fronts don't like to just blast thru this time of yr. Now models have kept the warm front SW of NYC. Therefore, I will fcst similar temps to the past two days, once again going a smidge under guidance. It is not totally impossible for models to go back north, which would render this fcst way too cool. In addition, those who get into the warm sector could see a round of strong t-storms later in the day Sun. For now, I am keeping all of that from NYC S & W. Therefore, our area should be cloudy and cool, but dry, after the morning rains.
The next model issue is for Mon. Some models develop a weak coastal low off the NJ coast, which would "re"increase rain chances later Sun night into at least the first part of Mon. Latest guidance is trying to develop a high pressure lobe into Central New Eng. If that happens, it would dramatically lower chances of rain, esp for NE CT. I want to avoid flip-flopping the fcst too much. Therefore, I envision POPs being layered something like low-end likely in SW CT, to slight chance in NE CT, w/adjustments, of course, being possible. One thing I am fairly confident about is the coastal low will be close enough to keep us cloudy all day, and with cold high pressure to our N/NE and a cool N/NE flow, guidance appears way too warm. I have gone ahead and subtracted a good 8 deg or so from current guidance. Expect highs only around 50 on Mon!
Tue looks to be a bit interesting, as well. Skies do look to clear, as the coastal low pulls away. However, an upper level low will spin into the area. Convective temps are very low on modeled soundings. Therefore, there is a chance for showers and t-storms to develop with at least scattered coverage in the afternoon. Guidance temps appear reasonable, so highs should be in the low 60s.
For now, Wed looks like it could turn out to be the nicest day of the week, as models have us in between upper level lobes. If this is true, sunny and pleasant w/guidance temps generally accepted, and highs turn out in the low 60s.
On Thu, another upper level low approaches. Convective temps look even lower, and a cold front will also approach. With all this going on, I have trimmed a few deg off guidance, and I would only expect highs in the mid to upper 50s. As the upper level low approaches, isolated to scattered showers and t-storms should fire. There is the potential for sleet or small hail to mix in, esp the further N you go with very cool upper levels.
The long range looks to feature generally below normal temps. There is a pretty strong signal for a coastal low in the 4/19-20 time frame. There could even be p-typ issues for the highest elevations if today's modeling is correct! But that's way out and for much later shifts to evaluate.
Now, let's look at some graphical interpretations of wx systems that will affect the area in the coming week. First, let's start with Sun Morn's overrunning rain. This map, valid dawn on Sun, clearly shows lots of rain over the state, with quite a bit more to go.
Next, look at this graphic, valid midnight Sun night. Note the high pressure lobe to our N. If this feature is real, it will suppress the rain for all but extreme SW CT. However, it may not be real as other models are much weaker with it.
Anyway, that's all for now. I'll see everyone next week!
-GP!
-GP!
