(7:55am Sat) EXCESSIVE HEAT WATCHES CONTINUE ACROSS WMASS, CMASS, AND MUCH OF CT FOR SUNDAY AND MONDAY AS HEAT INDICES CLIMB TO 105+ DEGREES… HEAT ADVISORIES CONTINUE FOR SVT, SWNH AND ENY… THE HEAT WAVE BEGINS FOR MOST TODAY… PEAK HEAT AND HUMIDITY SUNDAY AND MONDAY…
Good morning everybody, because I posted last night when most people were out, I am reposting last evening’s report with a few modifications, since it all still applies. Again, I have produced a report that has a summary up top, and a discussion below. The bullet list will hopefully keep you moving along faster.
If you could, please help spread the word by getting this post out to others, and please do read the Summary and Discussion below as our heat wave arrives today, and will be impactful, especially to the elderly, the young, and pets. Stay cool, kids!
SUMMARY
–Highs today will reach the low to mid 90s with dewpoint temps rising fully into the 60s
–This will prompt heat indices to rise into the mid to upper 90s, and possibly over 100 degrees
–While the Excessive Heat Watch will cover for the Heat Advisory today, be aware that impactful heat starts today
–Lows tonight will be in the low 70s as humidity continues
–Sunday will be the hottest day of the stretch, with highs in the mid to upper 90s, and possibly reaching 100 degrees for some
–With dewpoint temps rising into the upper 60s to low/mid 70s, heat indices will likely crest 105 degrees
–If this looks likely, Excessive Heat Warnings will replace the Excessive Heat Watches in place now
–There is a remote chance a flow out of the northeast in the form of a backdoor cold front will try to push into CMass
–This could knock temps down into the 80s to low 90s there, but I think we stay in the mid to upper 90s in WMass, SVT, SWNH, CT and ENY
–Monday looks a couple of degrees cooler, but it won’t matter.
–Low to mid 90s looks likely into at least Tuesday, if not through the whole week, though some potential exists for 85-90 on the 4th of July. More as we get closer. Discussion below…
DISCUSSION
Good morning everybody, one big reason for the upcoming weather is that the northern branch of the jet stream (the fast moving river of air that exists above 30,000 feet in altitude) will be blasting northeast into Canada through next week, which will open the floodgates for hot air to advect into New England at all levels of the atmosphere.
This will help to promote the development of a ridge. In meteorology, altitude levels are measured in the form of pressure levels, and millibars are the unit used to measure pressure.
For example, a 500mb pressure level is usually found at an altitude of about 17,500 feet aloft. When these pressure levels rise higher than their normal altitude levels, a ridge is said to develop – sort of like an upward/outward bulge of air, if you can picture that. Ridges promote high pressure and sinking air at the surface, along wtih warmer/hotter air temperatures.
Having said that, a very strong mid-level ridge will set up over New England this weekend and into early next week, ensuring that we soar into the 90s for high air temps and the low 70s for low temps.
You can see the 594 decameter ridge over New England in the map/graphic below. 594dm = 5940 meters, which equals about 19500 feet – that’s almost 2000 feet higher than normal for the 500mb pressure level, which is a lot!
Meanwhile, another high pressure system will develop off the east coast which will also help to pump in the humidity, with dewpoint temps rising into 70s by Sunday. Expected high temps for Sunday and expected dewpoints for Sunday are in attached graphics as well. Lastly, please check the attached graphic from the NWS for dealing with your car and the beings in it during heat waves!
NORTHAMPTON COOLING CENTERS OPENING…
Also please click on the link below for more information on this valley resource to help mitigate the heat.
Please remember to stay hydrated, stay cool, wear protective light layers to mitigate skin damage from the sun without overheating, keep your pets inside, and by all means do NOT keep your kids or pets in a car with the windows up! Have a great day and stay cool!
http://www.gazettenet.com/Heat-wave-coming-18518834