textproduct: Burlington

WHAT HAS CHANGED

As of 222 AM EDT Wednesday...

No changes to the current forecast.

KEY MESSAGES

As of 222 AM EDT Wednesday...

1. Drier air finally will work its way into the region today with temperatures sharply warming through Thursday.

2. Shower chances return Thursday afternoon into Friday with localized breezy conditions, mainly in the St. Lawrence and Champlain Valleys.

3. Cooler than normal early next week with a slight threat of showers late Sunday-Monday.

DISCUSSION

As of 222 AM EDT Wednesday...

KEY MESSAGE 1: Satellite this morning depicts widespread low stratus across the entire area with intermittent mist in the higher terrain, in association with lingering low level moisture evident on the GOES- 19 water vapor imagery. Blocked flow and a sharp inversion will likely keep these clouds and terrain mist/fog lingering through this morning, with froude numbers still well below 0.25. By this afternoon, model soundings show mid to upper level drying finally making it to the surface with froude number improving. Low clouds look to break by this afternoon, though mid to upper level clouds from convective blowoff from the southwest will arrive just in time to keep us partly to mostly cloudy thereafter. Some sunshine may try to work its way in in some of the wider valleys. All in all, today will be a quiet, tranquil day.

Winds will turn more southerly today as high pressure nudges north from the Mid-Atlantic. This will usher in a much more milder air mass as temperatures warm into the low 70s today, and into the low to mid 70s by Thursday. Complicating our maximum temperature potential Thursday, however, will be the presence of advected low level moisture and potential shower activity, described in key message 2. Humidity will also be on the increase as Pacific tropical moisture from the southwest advects to the northeast along a frontal system by the late week. Dewpoints will increase to around 60 degrees by Thursday afternoon.

KEY MESSAGE 2: A brief pattern change will take place by the latter portion of the week as shower chances and warmer temperatures return to the region, associated with Pacific tropical air. Zonal flow Thursday will turn more amplified to the southwest by Friday, advecting warm air and higher dewpoints in the region. Decent isentropic lift along an approaching warm front in the St. Lawrence Valley will spur shower chances by Thursday afternoon. Trends continue to support at least some isolated shower chances in northern New York during the day Thursday, though the GFS continues to hold precipitation across the border in Ontario until closer to Friday morning. Regardless, by Friday morning, a cold front will push through the region with elevated PWs up to 1.5-1.8"; more reminiscent of a summer-time airmass. Thankfully, this front will be quite progressive, aided by a 50-60kt LLJ, and good stretching between a Bermuda high, and a building high across the Midwest. As a result, ensembles depict only a couple tenths of an inch of rain, mainly across northern New York and the spine of the Greens in Vermont. Only a 10-20% chance of exceeding 1" of rain exists in the GEFS and Euro ensembles, and is focused only over the St. Lawrence Valley. There are no indications for heavy rain, though warm rain processes will support downpours and locally higher rainfall amounts.

As our flow pattern turns more southwesterly on Thursday, our gradient flow will also tighten with localized gusty winds expected. Soundings depict gusty channeled flow in the Champlain Valley winds with reasonable winds in the 25-30+ MPH range. Across northern New York, slightly stronger channeled flow is expected with winds in the northern St. Lawrence Valley in locations like Malone, NY, approaching 35 MPH out ahead of the cold front during the day Thursday. Given climatology, sustained winds look marginally strong in this area but gusts will not be impactful. Mountain summits will likely remain gusty around 40 MPH Thursday through mid day Friday. Winds look to weaken through the day Friday as the frontal system continues to track east.

Behind the cold front, Friday night, clouds will clear from west to east towards sunrise Saturday with the potential for climo favored valley fog and seasonably cool temperatures overnight. However, winds will remain fairly breezy, complicating the fog forecast. Temperatures may approach 40 in the higher terrain and in the 30s for the ADKs and portions of the NEK overnight Friday.

KEY MESSAGE 3: As has been the case since August, pretty much being dictated by northern stream flow with varying amplitudes and strengths of disturbances.

A northern stream shortwave and surface low track across Ontario and Quebec Sunday night-Monday with a chance of showers, especially northern sections and much cooler air on its heels. By Tuesday morning lows will be in the 20s-30s with highs in the 50s with some upper 40s as well.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

Through 12Z Thursday...aT 12Z, Conditions remain a mix of VFR- IFR across the area based on the height of the stratus layer. Gradual improvement is likely, and most locations should be near or at VFR conditions after 18z. Increasing mid clouds and a southwest gradient should keep VFR for tonight in NY but some patchy fog possible from eastern slopes of the Green mountains eastward.

Outlook...

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

BTV WATCHES/WARNINGS/ADVISORIES

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