textproduct: Burlington

WHAT HAS CHANGED

As of 247 PM EDT Sunday...

Prolonged dry weather upcoming, with good radiational cooling nights leading to areas of frost away from the Champlain Valley starting Monday night.

KEY MESSAGES

As of 247 PM EDT Sunday...

1. Rain ending late this afternoon; patchy fog overnight then tranquil wx conditions.

2. High pressure will provide region with dry conditions and cool temperatures through most of the week, before the chances of showers increase late Friday into next weekend

DISCUSSION

As of 247 PM EDT Sunday...

KEY MESSAGE 1: Low-amplitude 850-700mb trough departs ewd this evening allowing stratiform rain to taper off quickly. Clearing line has already reached the immediate St. Lawrence Valley as of 18 UTC. Lingering light rain across central/ern VT should exit east of the CT River Valley by 2030 UTC. With wet low-level/soil conditions, it appears that patchy dense fog will develop in spots after sunset. NAM/HRRR/RRFS model soundings all show a better surge of low-level CAA during the pre-dawn hours, and better mixing may yield more low stratus as opposed to fog as we head towards daybreak. Either way, should see a combination of fog/low clouds helping to keep overnight lows mostly in the low-mid 40s areawide. A few 30s are possible in the nrn Adirondacks especially around KSLK. Winds will also pick up on Lake Champlain out of the north late (see Marine section below).

Large area of high pressure building esewd from northern Ontario will then be our controlling weather feature Mon-Thu. Low clouds gradually clear on Monday with increasing large-scale subsidence, leading toward crisp fall like conditions through the remainder of the short term forecast period with PoPs NIL. Looking for highs in the upper 50s to lower 60s on Monday, then generally low-mid 60s for Tuesday and Wednesday. Overnight lows in the 30s to lower 40s with good radiational cooling conditions expected. Look for some patchy frost away from the Champlain Valley Monday and Tuesday night...and locally widespread frost in the northern Adirondacks and Vermont's Northeast Kingdom.

KEY MESSAGE 2: Guidance is in good agreement through late week with regards to large high pres anchored over southern Canada and keeping our fa dry. However, a large spread begins to develop Friday into next weekend with regards to evolution and track of coastal low pres, and potential impacts to our cwa. Attm WPC continues to keep chc pops into the fcst for late Friday into next weekend, with highest probabilities acrs central/eastern VT and <10% near the International Border. Initially, deep dry layer in place with pw values btwn 0.20 to 0.40" wl produce sunny conditions on Thurs with seasonably cool temps. Highs generally in the upper 50s to mid/upper 60s Thurs/Friday with lows mid 30s to mid 40s. It should be noted, the lows fcsted by WPC, especially Weds and Thurs nights are too warm, given MEX at SLK is 24F and 28F, while WPC has 34F and 33F. Similar scenario is noted acrs central/northern and eastern VT, where daily frost advisories will probably be required, given the favorable setup for cool night time. As clouds and moisture slowly advect back into our cwa by next week, daily low temps warm back into the 40s, but cooler daytime highs with northerly flow are possible by next weekend. The bottom line is we are not expecting any widespread hazardous or significant weather late week into next weekend attm.

AVIATION /00Z MONDAY THROUGH FRIDAY/

Through 00Z Tuesday...A wide range in flight conditions continues this evening from IFR at BTV to MVFR at MPV/RUT/EFK and VFR at MSS/SLK/PBG. Expecting variable conditions with the onset of some fog/br and associated IFR/LIFR to occur pretty quickly, given recent rainfall and light winds. However, a secondary cold front pushes across our region between 06z-09z, expect areas of fog/br to transition into IFR cigs with MVFR vis, as low level stratus develops under blocked flow and low level northerly flow. Highest probability (60-70%) of long duration 8-14 hours)of IFR/LIFR is at SLK/MPV/RUT, with medium confidence (40-60%) at BTV/EFK and intervals of IFR or lower conditions possible at MSS/PBG. Greatest potential for fog at most sites will be between 02-08z this evening, with more stratus likely after 08z, especially mountain sites and east side of CPV. Conditions are slowly improving to MVFR by 15z and mostly VFR by 18z Monday. South/southeast winds become light this evening and shift to the north/northwest after 06z tonight and increase 5 to 10 knots by sunrise.

Outlook...

Monday Night: VFR. NO SIG WX. Tuesday: VFR. NO SIG WX. Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. NO SIG WX. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: VFR. NO SIG WX.

MARINE

As of 247 PM EDT Sunday...Near Lake Wind Advisory criteria will be in place around sunrise on Monday with increasing over-lake lapse rates bolstered by northerly gradient flow and low-level cold air advection. North winds generally 15-20 kts, but a few gusts to 25 kts are possible, especially across the central and southern portion of the broad lake and down towards Diamond Island. Wave heights in this region should reach 2-3 feet between 11-16 UTC before subsiding Monday aftn.

BTV WATCHES/WARNINGS/ADVISORIES

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