textproduct: Burlington

WHAT HAS CHANGED

As of 649 PM EDT Tuesday...

Increased PoPs over the next few hours as snow showers remain persistent but become localized.

KEY MESSAGES

As of 244 PM EDT Tuesday...

1. Snow showers quickly dissipate this evening with much below normal temperatures expected tonight.

2. Near critical fire weather conditions possible for parts of the area on Thursday due to gusty winds and low humidities.

3. After a late week frontal passage, seasonable and mostly dry conditions will follow for the weekend. Additional rain chances are expected through early next week with abnormally warm temperatures.

DISCUSSION

As of 244 PM EDT Tuesday...

KEY MESSAGE 1: Interesting early April conditions acrs our fa today, with potent s/w energy and pocket of favorable mid lvl moisture, combined with favorable instability parameters to produce widespread convective type snow showers. Stowe high elevation snow plot cam indicates 3-4 inches of snow has accumulated, with just over an inch here at BTV. Moderately strong caa has developed on brisk northwest flow, as temps have dropped to 29F here at BTV with 17F atop Whiteface summit as weak low pres tracks toward Cape Cod. GOES-19 visible satl imagery shows quickly dissipating cloud cover approaching SLV with sfc dwpts falling back into the lower single digits, as much drier air advects into the region. Expect any lingering snow showers to dissipate by sunset this evening with drier air and loss of sfc heating/instability. Temps with areas of fresh snow pack and building 1036mb high pres should drop quickly after sunset. Have trended lows toward cooler guidance with values in the single digits to near 20F, coldest SLK/NEK.

Weds should feature plenty of sunshine with 1036mb high pres directly overhead with deep dry layer and light winds. Have continued to trend sfc dwpts near the NBM 10th percentile, which supports RH values in the 20% to 35% range. Winds wl be trrn driven and under 8 mph. Highs range from near 32F summits to mid/upper 40s deeper valleys.

KEY MESSAGE 2: Near critical fire weather conditions possible for parts of the area on Thursday due to gusty winds and low humidities. The strongest winds are expected over the northern Champlain Valley and parts of northern NY, while the lowest humidities will be across the deeper valleys locations of VT on Thurs aftn.

Mid/upper lvl trof and associated weakening boundary approach our cwa on Thursday with strengthening low lvl wind fields. Progged 925mb to 850mb winds increase btwn 30 and 50 knots on Thurs, while high pres is shifting off the East Coast. Soundings at BTV show inversion height around 925mb with top of the mixed layer of 40 knots, so anticipate enhanced channeled flow acrs the northern/central CPV on Thurs morning. Localized gusts 30 to 40 mph possible around sunrise at BTV. As sfc heating occurs mixing heights increase to 900mb, which wl continue to produce localized gusts up to 40 mph, but also help to mix drier air near ridgetops toward the sfc. Have utilized NBM 10th percentile dwpts to lower min RH values into the 22% to 35% range, with driest air acrs central/eastern VT. Winds wl be lighter in the CT River Valley and parts of central/northern VT, including the NEK with gusts in the 15 to 30 mph range, as stronger gradient is acrs the CPV and parts of northern NY on Thurs. Depending upon how quickly fine fuels dry out on Weds and after coordination with our fire weather partners, we may need an SPS for near critical fire weather conditions. Progged 925mb temps in the 6-10C with favorable southerly flow support highs well into the upper 50s to mid 60s, especially downslope areas of the northern Dacks and parts of the CPV away from Lake Champlain.

KEY MESSAGE 3: A frontal system is forecast to track across the area Friday bringing chances for rain for most of the region, through uncertainty in amounts remains. Models have trended towards a wetting rain with a low that tracks either over or just north of the region. Ensembles denote precipitation totals between 0.25-0.5 inches, with solutions favoring an overhead track yielding the higher threshold precipitation amounts. These higher solutions include the GFS, whereas lesser amount solutions include the ECMWF. Regardless, widespread precipitation chances exist during the day Friday before clearing out Friday night. More seasonable temperatures will follow this system for the weekend with more dry and seasonable conditions. Daytime highs will be in the 50s with overnight lows in the mid to upper 30s as high pressure builds in Saturday. Saturday night will be the cooler of the two days as the high crests over the region.

Temperatures will begin a warming trend heading into next week as our flow becomes south dominant with our high sliding east. 925mb temps will warm to 15-20C Monday and Tuesday, peaking Tuesday afternoon. These warm upper air temperatures will support surface highs in the mid to upper 60s, and perhaps near 70 degrees to start next week. These warm temperatures will be accompanied by breezy to gusty afternoon winds and shower chances as a boundary will be draped to the northwest. Shortwaves will ride along a positively- tilted long wave trough across the Great Lakes leading to rounds of shower chances, mainly across northern New York and extreme northwestern Vermont which could inhibit the max heating during the afternoon hours. A low level 850mb jet between 50-60 MPH will also lead to breezy to gusty winds in the south to north oriented valleys in addition to the warmup expected. Mid April looks to give a us a renewed taste of the summer to come.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

Through 00Z Thursday...A stationary frontal boundary sits draped across northern New York and Vermont this evening, continuing to produce snow showers across the region. This along with blocked flow will continue changeable conditions over the next few hours. Most sites are reporting MVFR or VFR ceilings anywhere from 1100-5000 feet above ground level. Snow showers are expected to dissipate this evening, but have been causing visibilities as low as 1-3 miles over the past hour. As drier air flows into the forecast area, we anticipate VFR ceilings to become widespread by around 02Z-03Z Wednesday. Snow showers are forecast to linger longest at SLK, EFK, and RUT, finally coming to an end around 04Z-06Z Wednesday as skies clear. Winds currently out of a number of directions, largely terrain- influenced, should become lighter and potentially even calm by around 06Z-10Z Wednesday for some.

We continue to see the GLAMP model project IFR fog tonight in several locations, though run to run it is not consistent. It is possible that the GLAMP is underestimating the dry dew points that are observed in real time moving toward the region and believes temperatures crossing dew point thresholds tonight will result in fog. Several high resolution models also maintain a light but persistent surface level wind in many spots throughout the night that could prevent or at least break up patches of fog. We can't entirely discount the GLAMP considering the close proximity of the stationary boundary previously mentioned and the incoming clear skies/potential calm conditions, but at this time, the observed dry air and the general model consensus has us keeping fog out of the TAFs other than a period of 3 miles vis at SLK. Winds will increase again out of the south-southwest around 12Z-18Z Wednesday but remain under 10-15 knots.

Outlook...

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 MVFR, with local IFR possible. Chance SHRA. Saturday: Mainly VFR, with areas MVFR possible. NO SIG WX. Saturday Night: VFR. NO SIG WX. Sunday: VFR. 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.