Visible Satellite Image 4:45 P.M.
The upper-level steering flow will continue to feed some moisture in from the southwest during the next 24-36 hours. The result will be partly cloudy conditions tonight and a fair amount of high and mid-level clouds Saturday (mixing with some filtered sun). Conditions will remain dry & comfortable. Lows overnight mostly between 53-61 and highs Saturday between 78-84. Saturday night looks mostly cloudy with lows between 57-62. Sunday is still a bit tricky to forecast, but at this point it looks partly cloudy with maybe a 30% chance for a shower. Highs in the low 80′s, though dependent on how much sun we see. Monday’s outlook: mostly sunny. Highs 78-84. It turns hot & humid for the middle of next week. Tuesday & Wednesday feature a mix of sun & clouds, with highs 85-90. There could be a scattered shower or t-storm somewhere on one or both of those days.
NAM Forecast for 2 PM Sunday
The mid-upper level trough that produced a couple scattered but locally heavy showers in parts of western CT/western MA/SE NY this afternoon will lift out to the northeast overnight into Friday. High pressure builds in at the surface, resulting in dry & comfortable conditions Friday & Saturday. Low temperatures tonight 52-60 as the sky becomes mostly clear. Lots of sun Friday, with highs 80-85 and low humidity. I think we will see high and mid-level clouds mixing with some sun Saturday. Highs will be in the low 80′s. An inverted trough (see image) will be lurking just offshore Sunday. Could make for a partly to mostly cloudy day, with maybe even a shower to the south & east. Highs 75-80. Monday looks mostly sunny. Humidity starts creeping back during the day. Highs 80-85. Warm & humid Tuesday, with the chance for a scattered shower or t-storm. Highs in the mid-upper 80′s.
Radar 8:30 P.M.
Areas of heavy rain and thunder moving in now from the southwest. I expect to see some flash flood warnings going up tonight.
Northeast Surface & Radar 5:17 P.M.
The severe weather this afternoon remained to the southwest & northeast of CT. There are still a number of thunderstorms moving up across MD & NJ and some of this will reach us during tonight. We can expect periods of showers and the threat for a thunderstorm tonight. Any storms have the potential to produce torrential downpours. It will be muggy again tonight with lows around 70 degrees or so and some areas of fog. Some lingering rain into Wednesday morning, followed by partial clearing by afternoon, along with a bit of a break in the humidity. A Flash Flood Watch remains in effect until 2 PM Wednesday for all of CT, except Litchfield & Fairfield Counties where it ends at 6 A.M. Highs tomorrow 77-84. Looks partly sunny Thursday, although I wouldn’t be surprised if a few spots saw a shower due to a mid-level trough. Highs will be in the low 80′s. Friday & the weekend look good, if you like mostly sunny weather with seasonably warm temperatures (low-mid 80′s) and fairly comfortable humidity levels.
It’s uncommon to see a hurricane moving up the east coast during the first week of July. I don’t recall it happening before in my 51 years. Haven’t had time to determine the last time this occurred so early. I believe the earliest major (Cat 3+) hurricane on record that moved up toward the North Carolina coast was Hurricane Able in May of 1951.
Hurricane Arthur will pass to our southeast tomorrow, passing close to the “benchmark” (70 degrees W longitude, 40 degrees N latitude). It does not appear that it will have a direct impact on CT, southeastern NY, and western MA/NH, but it will generate dangerous rip current offshore (not that you’ll want to go to the beach tomorrow, anyway). A tropical storm warning is in effect from Nantucket to Martha’s Vineyard, to Block Island to Montauk Point, Long Island, and 20 nautical miles offshore Friday.
There will, however, be a channel of moisture over us, associated with a frontal system. This will result in a rainy 4th of July, with highs in the 70′s. The rain will taper Friday evening, followed by some clearing and decreasing humidity during Friday night. Lows will drop into the 50′s in many locales late Friday night. The weekend looks nice! Sunny Saturday, with lower humidity and seasonably warm temperatures (low 80′s). Mixed sun & clouds Sunday, with highs in the low-mid 80′s and comfortable humidity.
Summer finally arrives at 6:51 A.M. EDT Saturday! It’s not the longest day of the year (all days are 24 hours long), but it will have the most daylight – 15 hours & 15 minutes! Sunrise occurs at 5:15 A.M. and sunset occurs at 8:30 P.M. After a relatively cool night tonight (partly cloudy, lows 45-53), the first day of Summer looks dry & comfortable. We will see a mix of sun & clouds with low humidity, and highs in the 75-80 degree range. There is a mid-level trough passing over us this weekend that will mix in a few clouds, but the air may be too dry to support any sprinkles or scattered showers. So, Saturday night looks partly cloudy with lows mostly in the 50′s. Sunday will also feature a mix of sun & clouds. Highs between 78-83. Monday & Tuesday look dry & warm, with sunshine and highs between 80-85, except for some cooler shore points.
NAM 500 millibar Forecast 2 PM Friday
The steering flow aloft will be coming out of the northwest during the next several days as surface high pressure builds down from that direction. The pattern aloft is more or less blocked for the next several days, so we should stay mostly dry until the middle of next week, after the pattern breaks down. Low temperatures tonight will be on the cool side: 48-55, under a clear sky. Should be mostly sunny through the weekend and probably Monday & Tuesday as well. High temperatures 75-80 Friday and mid 70′s-low 80′s over the weekend. Highs 80-85 Monday & Tuesday. Low humidity tomorrow & Saturday, with dewpoints in the 40′s. Dewpoints mostly in the 50′s Sunday-Tuesday.
Surface Map 2 PM Wednesday
A weak wave of low pressure will slide east along a frontal system that is south of us and migrating northward tonight. This will produce an increase in clouds late tonight and the chance for a shower toward morning, along with a few showers during the morning hours on Thursday. The further south you go, the better the chance to run into these showers in the morning. Then it will become partly sunny with highs 80-85. Friday & the weekend look nice – dry & comfortable, with highs in the upper 70′s-low 80′s.
NAM Forecast 2 AM Wednesday
We can expect a mild & muggy night across the region, with low temperatures in the 60′s. There is a fair amount of energy & instability present, which could result in a t-storm. An approaching low pressure trough (purple dotted line in image) could be the trigger mechanism for this late tonight/predawn. After the trough passes, our wind will shift into the northwest and increase. This should bring down the humidity a tad tomorrow. Wednesday will be partly to mostly sunny, breezy, and very warm, with highs 85-90. The trailing cold front arrives Wednesday night with the slight chance (20%-30%?) for a shower. Otherwise, partly cloudy with lows 59-64. With a little luck, most of Thursday-Sunday will be dry & comfortable.
NAM Forecast 2 PM Saturday
A band of thunderstorms with heavy rain is slowly moving across southeastern NY. This should weaken as it moves into western portions of southern New England a little later this evening. The chance for a shower or two and maybe some thunder will be with us tonight, as a cold front approaches from the west. It will be a humid night with areas of fog and lows between 60-65. Conditions will improve this weekend, however a lagging trough aloft will probably result in some lingering cloudiness for a while Saturday morning, and in some places, maybe a shower. This will be followed by developing sunshine and decreasing humidity, as a northwesterly breeze kicks in. After that, we’re good to go for a few days. Saturday night will be clear and on the cool side, with lows in the low-mid 50′s, and even some upper 40′s possible in some of the outlying areas toward dawn Sunday. Father’s day looks superb, with sunny skies, comfortable humidity, and highs between 80-85. After that, we’ll probably be looking at highs between 85-90 away from the coast Monday-Wednesday.