textproduct: Burlington

WHAT HAS CHANGED

As of 240 PM EDT Sunday...

Moderate rainfall expected during the pre-dawn hours Monday. QPF amounts increased to 0.5-0.9 inches 04Z-15Z Monday.

KEY MESSAGES

As of 240 PM EDT Sunday...

1. Moderate rain redevelops tonight, mainly after midnight.

2. Warmest day this week will be Tuesday.

3. Slightly below normal temperatures and periodic showers are expected late next week into the weekend.

DISCUSSION

As of 240 PM EDT Sunday...

KEY MESSAGE 1: Areas of light stratiform rain this afternoon will generally end from west-east thru 20Z as first wave of 850-700mb warm advection shifts east of the North Country. Cloudy and cool conditions will persist through the evening hours, with some increase in S-SE winds to 10-15 mph. May still see some very light rain or sprinkles around, but generally expecting a 3-6 hour lull in precipitation for most sections with temps upper 40s/lower 50s this evening. Thereafter, increasing cyclonic mid-level flow and next wave of low-level WAA allows precipitation to redevelop from SW-NE during the overnight hours...mainly after midnight. With precipitable water values expected to increase to near 1.5 inches, rainfall is expected to be of moderate intensity through much of the 06-12Z period. Have increased QPF to 0.5-0.8" across the region thru 15Z Monday , with a few deterministic runs showing values of 0.92" (12Z NAM) and 0.94" (12Z GFS) at BTV. No hydro concerns, but combined with patchy fog, some slower travel conditions can be expected early AM Monday.

Low-level wind shift from SW-NW flow on Monday morning brings precipitation to an end with a very slow clearing trend, especially in the mountains. Should see partly sunny conditions by early-mid afternoon, and then mostly sunny toward early evening. Some modest CAA expected in the wake of departing trough...but the high late May sun angle should help push late afternoon high temperatures into the 70-75F range across much of the North Country for Memorial Day.

KEY MESSAGE 2: Narrow region of surface high pressure builds ewd from the Great Lakes into NY/New England on Tuesday, accompanied by low- amplitude ridging aloft. Following some early AM nocturnal fog, should see mostly sunny conditions areawide. Looking for 850mb temperatures to moderate to +12C to +13C, which should support valley highs in the 80-85F range, with upper 70s expected in the northern Adirondacks and Vermont's Northeast Kingdom. Tuesday projects to be our warmest day this week. Dewpoints holding in the low-mid 50s should help limit any heat related concerns. PoPs NIL.

KEY MESSAGE 3: Longwave troughing is favored to shift over eastern Canada resulting in a northwest flow pattern across the Northeast. This pattern favors cooler temperatures and rain showers across northern New York and Vermont as troughs move through the longwave pattern. Model guidance shows temperatures generally in the 60s to near 70 degrees for highs and lows in the 50s as flow and cloud cover likely keep temperatures down. Several trough passages are expected, but the timing and strength remain questionable. Some deterministic models show a more wrapped up low moving through the base of the trough towards Friday bringing a decent cold pool as its upper circulation moves through. This could point to some increased forcing, potential for heavier showers, and possibly a few snow showers across area peaks. However, these details shouldn't be relied upon at this time scale. Kept the forecast towards consensus which keeps all rain showers through about 5000ft MSL for now with best chances on Friday and more isolated to scattered shower chances Thursday and Saturday.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

Through 18Z Monday...A mix of VFR to IFR conditions exist with locations in Vermont trending more towards IFR in periods of rain with lower CIGs and more intermittently lower VIS. IFR conditions and LLWS will remain the primary aviation concerns through this forecast period as moisture levels remain high behind initial round of rainfall. Another round of rain from along a quasi-stationary boundary will likely drag CIGs lower overnight as LLWS dissipates with decreasing winds aloft in the 06-14Z time frame. Conditions begin to improve after 14Z, but IFR/MVFR CIGs may be slow to lift given how saturated low levels will be and how slow winds will shift behind the exiting system.

Outlook...

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

MARINE

As of 240 PM EDT Sunday...The Lake Wind Advisory remains in effect with sustained winds of 25kts from the SSE still noted at Colchester Reef as of 1740Z. Little change in winds are expected through early evening. It does appear there will be a gradual decrease in wind speed and gusts after sunset. Waves of 2-3ft over the broad portion of Lake Champlain are expected to persist through 06Z Monday.

BTV WATCHES/WARNINGS/ADVISORIES

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