textproduct: Burlington

WHAT HAS CHANGED

As of 320 PM EDT Wednesday...

Confidence in near critical fire weather conditions for portions of the region on Thursday has increased.

KEY MESSAGES

As of 320 PM EDT Wednesday...

1. Near critical fire weather conditions are expected tomorrow. Dry conditions will continue on Friday but with limited concern for fire spread with lighter winds.

2. Relatively quiet weather and seasonable temperatures are expected for the weekend into early next week, with increasing precipitation chances towards the middle of next week.

DISCUSSION

As of 320 PM EDT Wednesday...

KEY MESSAGE 1: Aside from a portion of southern Vermont where low altitude clouds were rather thick under the influence of a marine stratus layer, today was another seasonably warm and dry in a string of several similar days. An area of low pressure, mainly in the mid levels of the atmosphere and far to our north near Hudson Bay this afternoon, will be steered southeastward tonight. It will rapidly push into northern Maine tomorrow morning and drag a cold front through our region, with some spotty showers expected, with greatest chances of any measurable rain over northeastern Vermont closer to the low pressure area. This front will importantly shift winds to the northwest, and its surface reflection is expected to deepen just enough to our east to enhance the pressure gradient to support gusty winds during the day Thursday.

Conditions will be favorable for wildfires to start and become difficult to contain tomorrow afternoon. Our forecast continues to bring relative humidities towards the lowest model guidance and wind gusts towards the highest guidance during the day. Forecast soundings show a weak inversion during the morning and a lot of dry air that suggests sharply falling dew points (or dew point bomb). Since the cold air advection is rather weak, temperatures should still be fairly warm with full sunshine, topping out in the mid to upper 50s in the areas of most concern in the Champlain and Upper Valley. The northwest wind direction is less favorable for strong gusts in the St. Lawrence Valley, but across northern New York and much of western and southern Vermont (northeastern Vermont looks a bit less dry), relative humidity will likely drop to near 30%. Portions of the Upper Valley and southern Champlain Valley are especially favored to see minimum values near 25%. Wind gusts are going to mainly be 20 to 25 MPH. However, top of the mixed layer winds, which due to strong insolation are expected to deepen the boundary layer to near or above 800 millibars, will be in the 25 to 30 knot range. This would support the potential to overachieve on wind gusts, especially southeast/downslope of hills and mountain peaks. More details are provided in the Fire Weather Forecast and the latest Special Weather Statement.

The upper level pattern remains similar into Friday with even drier conditions expected. However, the orientation of the trough to our east and position of the ridge being more overhead rather than to our west should provide us somewhat cooler conditions and northerly flow that is a little less gusty compared to Thursday. Therefore, fire weather concerns are low at this time.

KEY MESSAGE 2: A relatively quiet stretch of weather is expected to continue heading into the weekend and the beginning of next week. While a few showers may be possible, high pressure overhead will keep most precipitation chances to our south across southern New England and the Mid-Atlantic. Relative dry weather is expected to continue through the beginning of next week, with more precipitation chances not arriving until Tuesday night or Wednesday at this time, which may be even later depending on how quickly ridging across the region breaks down. There is still plenty of uncertainty amongst model guidance, so details will become more certain as we get closer. Temperatures will generally be near seasonable normals for late April, with daytime highs in the upper 50s to mid 60s and overnight lows in the 30s to mid 40s.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

Through 18Z Thursday...VFR conditions are expected at most terminals through the period except KRUT and KMPV where MVFR ceilings are expected to develop by 15Z and 18Z respectively. Otherwise, winds will mainly be 6kts or less outside of the Champlain Valley, locally southeast at 8-12kts at KPBG and KRUT, and more southerly at KBTV where sustained winds over 10kts and gusts over 20kts are expected for most of the day, abating after sunset.

Outlook...

Thursday Night: VFR. NO SIG WX. Friday: VFR. NO SIG WX. Friday Night: VFR. NO SIG WX. Saturday: VFR. NO SIG WX. Saturday Night: VFR. NO SIG WX. Sunday: VFR. NO SIG WX. Sunday Night: VFR. NO SIG WX. Monday: VFR. NO SIG WX.

BTV WATCHES/WARNINGS/ADVISORIES

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