textproduct: Burlington

WHAT HAS CHANGED

As of 905 AM EDT Tuesday...

Quick update to fine tune pops as band of moderate to heavy snow associated with potent s/w energy is quickly approaching the CPV. Expect area coverage and intensity of snowfall to increase, as better moisture and dynamics arrive acrs the CPV and most of VT. Sounding data shows some instability, which wl result in higher snowfall rates, that could produce a quick inch or two on grassy surface and a slushy coating on roads. Upstream webcams confirm this idea, along with vis below 1/2SM at times.

KEY MESSAGES

As of 229 AM EDT Tuesday...

1. Widespread snow showers expected this morning into the early afternoon, with snow accumulations mainly 1 to 2 inches.

2. Warmer and drier conditions prevail for mid week, with increasing fire weather concerns, especially on Thursday.

3. After a frontal boundary brings late week precipitation chances, seasonable and mostly dry weather is expected for the weekend. Additional chances for rainfall are expected heading into early next week.

DISCUSSION

As of 229 AM EDT Tuesday...

KEY MESSAGE 1: Another round of snow showers is expected today as a weak clipper system crosses the region. This feature is currently moving through the northern Great Lakes early this morning, and it should continue to slide eastward along/just north of Lake Ontario and then overhead before moving offshore late today. Moisture is fairly meager with this system, and even at this stage, model guidance is having a hard time agreeing just how extensive shower coverage is going to be, and whether the most prevalent activity will favor the northern half or the southern half of our forecast area. Radar presentation isn't overly impressive with the system at this point, consisting mainly of a single north-south oriented area of showers (associated with the cold front/surface trough) followed by more scattered activity in the cold air advection behind the system. That being said, overall thought is we'll see scattered to numerous showers through the morning into the early afternoon as cold air advection and a bit of daytime heating help to steepen lapse rates. The system's forward motion is fairly quick, and showers will end by mid/late afternoon once the center is to our east. This with the lack of significant moisture will help to limit overall snowfall amounts. However, there could be some briefly heavy snow in more robust showers, with rates of 0.50 in/hr or more possible at times. So some quick accumulation will be possible, though it's uncertain how long any accumulation would linger before melting, especially on paved surfaces. Temperatures are mainly going to be in the upper 20s to mid/upper 30s, so precipitation should fall mainly as snow, even in warmer temperatures due to wet-bulbing. With all this mind, still expect most areas will only see an inch or two of accumulation, particularly on grassy or raised surfaces. Some locales in the higher elevations could see upwards of 3 inches, especially if multiple heavier showers move through. Travel could be a bit tricky at times as any heavier showers reduce visibility and produce a quick accumulation on roadways, so motorists are urged to use caution and remain alert for rapidly changing conditions.

Once the system exits this afternoon, we'll see a reinforcing shot of cooler and drier air with ridging following the departing clipper. Skies will clear and winds subside, so expect we'll see decent radiational cooling, especially anywhere that's able to hold onto a bit of fresh snow cover. The result will be a bitterly cold night with temperatures dipping into the teens areawide. A few spots may even get down into the single digits by Wednesday morning.

KEY MESSAGE 2: High pressure will be directly overhead on Wednesday, leading to plentiful sunshine and light winds. After today's chilly weather, we'll warm back up to near seasonal normal with highs expected to be in the 40s areawide. We should have optimal mixing, so dewpoints will be low, down into the single digits during the afternoon. As a result, minimum relative humidity levels will also be quite low, 20 to 30 percent.

The high moves off shore on Thursday, and anticipate increasing south/southwest flow on the backside of the ridge. Highs will warm well into the 50s to around 60F, and winds will become breezy. Gusts of 25 to 35 mph are possible, particularly in the Champlain and St Lawrence Valleys. While dewpoints won't be as low as on Wednesday, minimum relative humidities will once again drop to 20 to 35 percent, especially in Vermont. These conditions will create elevated fire weather concerns as these dry and windy conditions will allow any fires that start to rapidly develop and spread.

KEY MESSAGE 3: A frontal boundary draped across the region Friday will bring some chances for rain Friday into early Saturday, although there is still a good amount of uncertainty regarding this feature, especially in regards to exact timing and precipitation amounts, although it looks like fairly light and scattered precipitation can be expected. Once the cold front exits the region, high pressure looks to build in for the remainder of the weekend, bringing seasonably warm and dry weather. High temperatures on Saturday and Sunday look to climb into the 50s and 60s respectively. Another system will arrive early next week, bringing more widespread rainfall to the region. The latest NBM continues to show temperatures climbing into the 60s to lower 70s early next week under southerly flow, but these temperature trends will need to be monitored as we get closer, especially if widespread rain is expected throughout the day.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

Through 12Z Wednesday...All terminals are expected to trend towards MVFR over the next hour or so as snow3 showers overspread the region this morning. Ceilings are generally expected to remain MVFR throughout the morning into the afternoon, generally around 2000 ft AGL or so. Although MVFR conditions are in the forecast, both ceilings and visibilities, IFR conditions may be possible, especially within any heavier snow showers due to reduced visibilities. Any IFR conditions that do develop are expected to be relatively brief, but given the uncertainty have left them out of the forecast for now. Flight conditions are expected to improve towards 21Z or so as snow showers come to an end and high pressure begins to nose into the region, with VFR prevailing for the remainder of the forecast period. Winds will increase from the north this afternoon, with gusts of 20 knots possible, before trending back towards light and variable towards sunset.

Outlook...

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

EQUIPMENT

The Colchester Reef meteorological station is out of service. This site is not serviced by the NWS. An estimated return to service is May 1st. Please contact us if you observe winds significantly deviating from the recreational forecast.

BTV WATCHES/WARNINGS/ADVISORIES

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