textproduct: Burlington

WHAT HAS CHANGED

As of 249 PM EDT Sunday...

Expanded areal coverage of wind advisory to cover our entire forecast area and extended the time frame until 11 AM Tuesday.

KEY MESSAGES

As of 249 PM EDT Sunday...

1. High wind warning and wind advisories continue for multiple rounds of gusty winds expected Monday morning through Tuesday morning with the strongest winds expected along the northern Dacks and northern Western Slopes of the Green. Isolated to scattered power outages are possible.

2. Pockets of freezing rain expected east of the Green late this evening into Monday, which could cause areas of slick travel during the Monday morning commute.

3. A strong cold front will bring very changeable conditions Monday night into Tuesday, with rapidly falling temperatures and rain transitioning to snow. River rises are likely, but flooding is not anticipated at this time. Another period of strong winds is expected across northern New York in the wake of the cold front.

4. Seasonable weather expected for the latter half of next week, with a few chances for showers.

DISCUSSION

As of 249 PM EDT Sunday...

KEY MESSAGE 1: Sfc analysis places deepening 992mb low pres over nw IL, while 1034mb high pres is anchored over the Gulf of ME. As sfc low pres deepens to near 980mb by 12z Monday, the 925mb to 850mb wind fields strengthen acrs our cwa late tonight into Monday morning. Little change has occurred in our initial thinking for high winds on Monday morning with progged 925mb winds of 75 to 80 knots over the northern Dacks and 55 to 70 knots over the northern Greens, while 850mb winds are in the 70 to 85 knot range. Still some uncertainty on mixing potential with band of precip expanding northward associated with strongest low level wind fields and sounding data showing a weak/shallow inversion. However, did note the HRRRX at Malone sounding has 66 knots at 900' and 60 knots at 500' with bl sustained winds of 32 knots at 12z Monday. HREF prob of wind gusts >55 mph is 90 to 100% over northern NY on Monday morning. Thinking the warm downslope flow, should help to enhance mixing of stronger winds in the 500 to 1000' layer toward the sfc on Monday morning, especially along the Route 11 corridor from Malone to Ellenburg. Second wind max of gusts 45 to 55 mph wl occur along the western slopes from near Mendon to East Middlebury to North Underhill to Montgomery on Monday morning. Difficult to determine how far off the western slopes the winds develop, but a few gusts toward the immediate CPV are possible. Much lighter winds are expected over central/eastern VT, especially in the protected valleys on Monday morning.

Next period of gusty winds are possible on Monday aftn, especially as temps warm into the mid 50s to mid 60s. This wl increase mixing heights, allowing for localized gusts in favorable channeled southerly flow of 40 to 50 mph. Soundings support this thinking at BTV/RUT and Highgate, with slightly lower values at MPV/MVL and SLK. Still with 40 to 55 knots between 1500 and 3000 feet on Monday aftn, it won't take much mixing for isolated gusts in the 40 to 50 mph range, especially with warm bl temps and better mixing profiles.

As a strong sfc cold frnt approaches our cwa late Monday into Monday night, the progged 850mb jet restrengthens acrs central/southern and eastern VT at 60 to 85 knots. The strongest winds are closely associated with developing band of rain with heavier convective elements, so the amount of mixing to the sfc is tricky. However, given warm and humid air mass ahead of boundary, expect some of the stronger convective elements wl have the potential to produce localized gusts in the 40 to 50 mph range on Monday night. Greatest potential wl be over VT. A period of moderate to locally heavy rainfall is likely with fropa, given some weak instability, pw values btwn 0.75 and 1.0", which are 3 to 4 STD above normal, and nose of llvl jet helping to enhance moisture transport/advection into our cwa. Thinking rainfall in the 0.50 to 1.0 range, with isolated higher amounts possible. This combined with additional snowmelt wl cause some rises to near bankful on a few rivers.

KEY MESSAGE 2: A secondary warm front with low level easterly flow of Atlantic moisture and deeper moisture advection with southerly winds aloft wl produce a period of light rain late tonight into Monday morning acrs our fa. Cold air wl remain trapped in the deeper/protected valleys of central/eastern and northern VT during the pre-dawn hours, where sfc temps wl be in the 29-32F range. This wl likely produce pockets of freezing rain with just a minor light glaze possible in a few colder spots. The areal coverage/amounts and impacts should be limited, therefore no advisory, but a SPS maybe needed for several hours on Monday morning. The HREF shows only a small portion of the central/southern Greens and valley pockets of 50% to 70% prob of ice accumulation >0.04". This precip wl be associated with a strong south/southeast jet at 850mb of 60 to 75 knots, so anticipate some upslope enhancement and downslope shadowing to the qpf amounts on Monday morning acrs our cwa. QPF generally in the 0.10 to 0.25" range with localized higher amounts eastern Essex, NY and southern Greens near Ludlow.

KEY MESSAGE 3: A strong cold front crossing the region Monday night into Tuesday will continue to bring multiple weather hazards to the region. While strong south winds and very mild temperatures will exist ahead of the front, conditions will change very quickly as the front moves through. Temperatures will sharply drop with the frontal passage, plummeting 15 to 20 degrees in a short period of time. These colder temperatures will allow for rain to quickly transition to snow, although there could be some of a wintry mix with all different precipitation types possible during the transition period, but any mix is expected to be short-lived. In general, snowfall amounts are expected to be light given the quick-nature of this system, with most locations seeing a dusting while the spine of the Green Mountains will see an inch or so. Higher amounts are expected across portions of northern New York where some enhancement from Lake Ontario is expected, but totals are still only 1 to 3 inches at this time. While river rises are expected across the region, flooding is not expected at this time, especially since we've already lost a lot of our snowpack. Current rainfall amounts expected with this system are generally anywhere from 0.5 to 1.0 inches, which will lead to some river rises and a few rivers reaching bankful. However, we'll still need to watch for any ice movement/jams on waterways in the Northeast Kingdom and far northern NY were river ice still remains. Another period of strong winds is expected in the wake of the cold front as the center of low pressure continues to pull away from the region. The strongest winds currently look to be across northern New York where channeled southwesterly flow will allow for wind gusts of at least 30 to 45 mph early Tuesday morning.

KEY MESSAGE 4: Although Wednesday will be cold, temperatures should gradually increase through the end of next week, with highs in the 30s and 40s and lows in the teens and 20s by the weekend. High pressure looks to build across the region , bringing a stretch of quieter weather for the middle of next week. A few shortwaves look to traverse across the region due to nearly zonal flow aloft, bringing a few additional chances for showers throughout the week. At this time, these disturbances all look pretty weak, with the details still uncertain at this time. Temperatures would support some mountain snow with any shower chances next week, with more rain/snow in the lower elevations.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

Through 18Z Monday...VFR conditions are expected to prevail across terminals over the next several hours, with ceilings remaining above 5000 ft AGL through the afternoon into the evening hours. A warm front will continue to lift across the region this afternoon, however little precipitation is expected to reach the surface. KMSS has the best chances of seeing any snow showers associated with this feature, with low chances of KBTV/KSLK/KPBG also seeing any showers. Since confidence is low, PROB30 groups were utilized to cover this potential. Behind the warm front, winds will become more southeasterly and rapidly increase, with gusts by 00Z rising to 15- 20kts, and 30-40kts by 06Z. LLWS will be a concern after 00Z Monday, with a strong jet of 65-75kts, leading to LLWS at all terminals for the remainder of the forecast period, with the strongest LLWS expected at KSLK. After 06Z, another round of showers will move through the region, falling primarily as rain but a few pockets of freezing rain cannot be ruled out, with KMPV the terminal most likely to be impacted. These showers will help trend ceilings towards MVFR, with most terminals expected to be MVFR towards 09Z or so.

Outlook...

Monday Night: Mainly MVFR, with local IFR possible. Windy with gusts to 30 kt. Definite RA, Definite SN. Tuesday: VFR. Windy with gusts to 30 kt. Slight chance SN. Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. NO SIG WX. Wednesday Night: VFR. NO SIG WX. Thursday: Mainly VFR, with local MVFR possible. Chance RA, Slight chance SN. Thursday Night: MVFR/IFR conditions possible. Slight chance RA, Slight chance SN. Friday: Mainly VFR, with local IFR possible. Slight chance RA, Slight chance SN.

CLIMATE

A daily record high temperatures and calendar day precipitation total are possible at KMSS (Massena, NY) on March 16th. The present forecast of 67 would be the previous record of 65 set just last year. Consensus forecast for KMSS is about 0.50-0.75", which would beat 0.44" set in 1994.

EQUIPMENT

The Colchester Reef meteorological station is out of service. This site is not serviced by the NWS and there isn't an estimated return to service at present. Please contact us if you observe winds significantly deviating from the recreational forecast.

BTV WATCHES/WARNINGS/ADVISORIES

VT...Wind Advisory from 11 PM this evening to 11 AM EDT Tuesday for VTZ001>011-016>021. NY...Wind Advisory from 11 PM this evening to 11 AM EDT Tuesday for NYZ026-028-029-035-087. High Wind Warning from 11 PM this evening to 11 AM EDT Tuesday for NYZ027-030-031-034.