textproduct: Burlington

WHAT HAS CHANGED

As of 229 AM EDT Wednesday...

No significant changes were made with this forecast issuance. Near critical fire weather conditions are expected today, followed by widespread rain tonight and Thursday.

KEY MESSAGES

As of 229 AM EDT Wednesday...

1. Near critical fire weather conditions are expected today, mainly from the Champlain Valley eastward.

2. Widespread rainfall is expected tonight and Thursday, with cooler and showery conditions persisting through Friday.

3. Unsettled and cooler conditions are expected to linger through the weekend into early next week.

DISCUSSION

As of 229 AM EDT Wednesday...

KEY MESSAGE 1: Yet another day of near critical fire weather conditions today, especially from the Champlain Valley eastward. While moisture will start to increase across much of northern NY this morning ahead of an incoming frontal system, VT will remain dry, with relative humidity values falling to around 30 percent this afternoon. Winds will be a little lighter than yesterday, with gusts generally 25 mph or less. While these conditions aren't as extreme as yesterday, our fire weather partners indicate fuels are very receptive, even without optimal conditions. Therefore, have issued a Special Weather Statement for the Champlain Valley and the rest of VT due to these concerns. Any one with plans to burn outdoors today should first check with local fire officials before setting any fires as they could quickly get out of control.

Otherwise, a frontal boundary stretched between two low pressure centers located to our west will gradually push eastward this afternoon. Moisture will stream northward ahead of this system, first into northern NY, where PWATs will approach 1 inch by mid/late afternoon. Although a few sprinkles will be possible this morning into the early afternoon, the bulk of the rain will hold off until closer to evening, mainly after 4 pm or so. The influx of clouds will keep temperatures in the mid to upper 60s across northern NY. Further east, clearer skies and less humidity will allow for another mild day in the mid 60s to low 70s.

KEY MESSAGE 2: The aforementioned front and double-barrled low system will gradually push eastward across our region Wednesday night and Thursday, bringing a period of steady and very welcome rain. The rain could be moderate at times, particularly in the St Lawrence Valley into the western Adirondacks. There could be a little CAPE there (200 J/kg or less) and HREF probabilities of rainfall rates exceeding 0.2 in/hr are 20-40% with any convection. Otherwise, expect just a general light rain for 6-10 hours. The front will exit to our east by Thursday afternoon, bringing the steadier rain to an end. However, with the upper low spinning down into eastern Ontario/western Quebec, showers will continue to be possible through the rest of the week, particularly during the afternoons as daytime heating and the cold pool aloft produce just enough instability. All told, rainfall totals have been reduced just a bit, but still expect most areas will range from around 0.50 inch to around 1.00 inch, with locally higher amounts if any convection is able to develop.

Temperatures will also cool quite sharply with this system, with 850 mb temperatures falling below 0C Thursday night and Friday. Highs on Thursday will only be in the mid 40s to mid 50s, and Friday will likely be a few degrees colder. Overnight lows both Thursday and Friday nights will be in the mid 20s to mid 30s, so frost could be a concern. Any lingering showers could well mix with and/or change to snow later Thursday into Friday morning, mainly above 1500 ft. Any accumulation would be minimal.

KEY MESSAGE 3: An upper level trough will remain over our region from Friday night through Tuesday night. This will bring us cooler than normal temperatures and several chances for light rain or snow showers. Snow showers will be possible mainly for elevations above 2000 feet. Highs are favored to be in the upper 40s to mid 50s, and lows in the 30s.

One thing to note is that the climatological start to the growing season in the Champlain Valley begins May 1st (this Friday) when we expect overnight lows to be near Frost Advisory criteria (32-36F) both Friday night and lesser so Saturday night. Cloud cover may limit the overall cooling that takes place, but conditions may be favorable for frost development. We will monitor this in the coming days.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Through 06Z Thursday...Through 06Z Wednesday...Winds becoming lighter overnight, but not tapering off entirely. VFR overnight. MSS likely to developing an MVFR cig around 3K AGL around 05z tonight, which should persist into 12-18z Wed. SLK could get an MVFR cig too, but going for just above MVFR cig in TAF starting 09z. Late in the period will have clouds and chances for precipitation beginning from west to east, 18z at MSS, 21z at SLK, 05z PBG and BTV.

Outlook...

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

BTV WATCHES/WARNINGS/ADVISORIES

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