textproduct: Burlington

WHAT HAS CHANGED

As of 255 PM EDT Saturday...

No significant changes made with this forecast package.

KEY MESSAGES

As of 255 PM EDT Saturday...

1. Pleasant weather conditions are expected through Monday with comfortable humidity, seasonable temperatures and dry conditions, before heat and humidity return by Tuesday, along with showers chances.

2. Hot and humid conditions expected for mid to late next week, with multiple rounds of showers and thunderstorms possible through the holiday weekend.

DISCUSSION

As of 255 PM EDT Saturday...

KEY MESSAGE 1: A narrow axis of mid lvl moisture, combined with some sfc instability from lingering bl moisture and heating has produced a few isolated showers over the Dacks. These showers wl dissipate with the loss of sfc heating/instability by sunset. Thinking patchy to areas of dense fog wl be likely again tonight, but probably not as widespread as last night, given a day removed from rainfall and slightly drier bl conditions. However, sfc dwpts in the 55-60F range this aftn, feel temps drop quickly aft sunset with many climo favored sites reaching cross-over values by 06z, supporting the development of fog/br under mostly clear skies and light trrn driven winds. Lows in the upper 40s SLK to near 60F BTV.

Sunday thru Tues a large scale pattern amplification occurs acrs the conus with deep 3 to 5 std below normal hghts acrs the western conus and building heat ridge over the MS/OH valleys. This synoptic scale pattern supports building heat and humidity acrs our cwa by Tuesday as ridge expands toward the Mid Atlantic States. A warm frnt with increasing moisture advection wl traverse our cwa on Tuesday with a band of showers and embedded thunderstorms. Instability wl be building behind the best warm frontal lift/moisture, so threat for strong/severe storms wl be minimal on Tues. Instead of 12 to 18 hours of likely or higher pops per NBM solution, given the timing differences, I cut 20 to 30% and kept pops in the chc range for now. As timing becomes better with near term high res guidance we can fine tune the pops to better match our thinking.

Progged 925mb temps are 17-20C on Sunday and Monday, but warm btwn 23-25C by Tuesday but with increasing clouds/showers possible. For now I have highs upper 70s to mid 80s Sunday/Monday and warm temps into the mid/upper 80s by Tues with bl dwpts warming into the mid 60s. Heat index values wl approach 90F by Tues in the SLV and CPV with 80s in the mtns. In addition, overnight lows wl be warming from the 50s into the 60s by Tues morning.

KEY MESSAGE 2: Summer officially arrives by mid next week with temperatures continuing to warm through mid week into the holiday weekend, peaking on Wednesday and Thursday. Ridging will crest over the Ohio Valley and extend into the Northeast by mid week, though some uncertainty remains on how extended the axis will be. Current trends have placed Vermont and northern New York potential on the eastern periphery of the ridge along a temperature gradient. This gradient will play a large role for how our weather plays out heading into the holiday weekend. Temperatures will peak towards the upper 80s to low 90s, with the NBM denoting the possibility of warmer temperatures. 925 and 850 mb temperatures in the ensemblistic guidance still only show values in the low to mid 20Cs, which would not bode temperatures above the mid 90s. Furthermore, guidance continues to show that reaching the low to mid 90s may be difficult as some ridge rollers along the periphery of the Ohio Valley ridge may lead to some increased cloud cover and afternoon shower and thunderstorm chances. With these patterns we tend to have a warm bias initially leading to the event as predicting the timing and position of these mesoscale features and convective debris clouds are difficult for the models to resolve. Regardless however, dewpoints will also increase towards the upper 60s to low 70s for Wednesday/Thursday. As dewpoints will be high, so will overnight lows, which will offer little relief with lows in the low to mid 70s. With the combination of the heat and humidity, heat index values may be around 100F. Should these heat index values become realized, the heat risk will be at or above major for Wednesday and Thursday for the entire region. In addition to the heat, daily chances for thunderstorms, some that may be strong, will be possible. With the increased heat leading to increasing instability, and high dewpoints, a recipe for strong thunderstorms is growing more confident for Wednesday and Thursday. Dangerously hot and humid conditions are expected nonetheless and anyone with outdoor plans through Thursday should stay aware of future forecasts and include both hot weather and thunderstorm safety precautions in your plans.

As we near the 4th of July and the holiday weekend, there may be some respite from the heat. The ridge axis shifts a bit south on the 4th, though temperatures will still remain in the upper 80s to low 90s with dewpoints in the mid to upper 60s. Heat and humidity will continue to slowly lower into the weekend with high temperatures into the mid to upper 80s.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

Through 00Z Monday...Cumulus is beginning to dissipate as peak heating has passed. Skies will be mostly clear overnight, and fog is expected to develop overnight. Fog is not expected to be quite as widespread being removed from precipitation about a day and having lower crossover temperatures. Still KMPV and KSLK may start falling below 1SM around 04-06z, and even less fog prone airports may still have fog nearby or briefly note drops in visibility, which are noted in TEMPOs. After 12z, fog should quickly dissipate and a few fair weather cumulus generally at or above 5000 ft agl are expected with northwest winds 4-9 knots.

Outlook...

Sunday Night: VFR. NO SIG WX. Monday: VFR. NO SIG WX. Monday Night: VFR. NO SIG WX. Tuesday: VFR. Chance SHRA, Chance TSRA. Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHRA, Chance TSRA. Wednesday: VFR. Slight chance SHRA, Slight chance TSRA. Wednesday Night: VFR. Chance SHRA, Chance TSRA. Thursday: VFR. Chance SHRA, Slight chance TSRA.

BTV WATCHES/WARNINGS/ADVISORIES

VT...None. NY...None.