textproduct: Burlington

WHAT HAS CHANGED

As of 247 PM EDT Thursday...

No significant changes made.

KEY MESSAGES

As of 247 PM EDT Thursday...

1. Scattered showers continue at times tonight into Friday, before drier and cooler air arrives on Friday night into Saturday.

2. Several rounds of rainfall expected through the first half of next week.

DISCUSSION

As of 247 PM EDT Thursday...

KEY MESSAGE 1: GOES-19 mid level water vapor imagery shows deep dry layer acrs our cwa, which has help to limit the areal coverage of showers this aftn. A weak impulse is approaching the Ottawa Valley with a pocket of better mid lvl moisture and instability and should be near the SLV by 22z this evening. This wl quickly move eastward acrs the Dacks, before falling apart in the CPV by midnight tonight. Have highest pops over the SLV/Northern Dacks this evening. Additional s/w energy is located north of Lake Huron and wl swing acrs our cwa on Friday with more scattered showers expected, especially favorable upslope areas of the Dacks and northern/central Greens. Soundings indicate lingering instability overnight, combined with upslope flow under llvl caa, should keep clouds persisting in the mtns, even after sunset this evening. These clouds and winds wl keep temps in the mid 30s to mid 40s.

For Friday, still thinking a few wet snow flakes are possible above 3500 feet, especially as progged 850mb temps drop below 0C per latest RAP13 data by 12z. Highest probability of precip wl be acrs the northern/central Greens and into parts of the CPV on Friday morning. Once again very steep lapse rates are anticipated on Friday aftn with summit temps in the mid/upper 30s, while valleys warm into the upper 50s to lower 60s. Favorable mixing should help to advect drier air aloft toward the sfc with dwpts falling back into the 30s and lower 40s again on Friday aftn with breezy west/northwest winds 15 to 30 mph.

By 12z Saturday 1032mb high pres is progged to be centered over northern NY, but 925mb to 850mb winds are still 15 to 30 knots from the northwest and some 850 to 500mb moisture is already approaching the area associated with waa. Have bumped temps upwards slightly from my thoughts yesterday, but still thinking mid/upper 20s SLK to upper 30s/lower 40s near Lake Champlain. Plenty of sunshine and comfortable temps are expected on Saturday with highs mid 50s to lower 60s. As sfc high pres shifts toward the Gulf of Maine, southerly gradient develops on Sat night into Sunday with moderate waa. Progged 925mb temps warm btwn 10-12C by 12z Sunday with increasing 925mb to 850mb winds of 20 to 35 knots. Progged soundings indicate a sharp and shallow llvl inversion developing Sat night, support a wide range temps from cooler valleys to warmer midslopes/summits with highs back into the 60s on Sunday.

KEY MESSAGE 2: The forecast is quite challenging late Sunday into Monday as the exact track of Hurricane Isaias will determine how wet the end of the weekend and early next week. The global deterministic guidance continues to show the remnants of Isaias bringing rainfall the region Sunday night and Monday morning while the ensemble guidance remains a bit split. A strong Bermuda high pressure system over the western Atlantic is expected to suppress how far east the remnants can initially track. A strengthening mid-level jet is expected to develop on the southern side of the remnants as the hurricane becomes extratropical which should push any precipitation associated with the remnants quickly across the region with no significant impact with rainfall amounts likely less than half of an inch. An upper level trough will likely continue in the wake of the remnants with a building ridge of high pressure expected across the central US. This will put Vermont and northern New York under northwesterly flow aloft with the potential for one or two cold fronts through the middle of next week with chances for rainfall associated with each of these fronts. Again, no significant rainfall is expected. The pattern overall is wet and messy, but isn't expected to be impactful.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

Through 00Z Saturday...Mainly VFR conditions expected through the TAF period, with localized MVFR ceilings possible early Friday morning. Isolated showers will continue to move eastward across the Champlain Valley and VT through 02z, but no visibility restrictions are expected. Skies to remain FEW-SCT AOA 5000 ft through 08z. Models then indicate low-level moisture will increase ahead of a weak surface trough moving south out of Canada 08z-14z Fri. Expect BKN- OVC ceilings 1500-2500 ft at SLK/EFK during this time, with lesser confidence at MPV. Elsewhere, ceilings will remain 4000+ ft. Clouds lift after 14z as mixing increases and MVFR will prevail thereafter. Additional scattered showers will develop again on Fri, but no visibility restrictions are expected. Winds will be light W/SW less than 8 kt overnight, trending a bit more NW and increasing to 6-10 kt with gusts to 20 kt after 14z Fri.

Outlook...

Friday Night: VFR. NO SIG WX. Saturday: VFR. NO SIG WX. Saturday Night: VFR. NO SIG WX. Sunday: VFR. NO SIG WX. Sunday Night: Mainly VFR, with areas MVFR possible. Chance SHRA. Columbus Day: Mainly MVFR, with local IFR possible. Slight chance SHRA. Monday Night: Mainly VFR, with local IFR possible. Chance SHRA. Tuesday: Mainly VFR, with local IFR possible. Likely SHRA.

BTV WATCHES/WARNINGS/ADVISORIES

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