What Has Changed
As of 232 AM EDT Friday...
No significant changes were made with this forecast package.
Key Messages
As of 232 AM EDT Friday...
1. A strong storm system will bring widespread rain and gusty winds today, followed by much colder weather and mountain snow showers on Saturday.
2. Next week continues to look very quiet with temperatures near normal and high confidence of an extended dry period of weather.
Discussion
As of 232 AM EDT Friday...
KEY MESSAGE 1: Low pressure is currently moving through central Michigan this morning, spreading rain across southern Ontario and into northern/central New York. Much of this rain isn't reaching the ground yet per NYS Mesonet observations, but expect it won't take much longer for the atmosphere to moisten enough for rain to arrive in earnest. This precipitation shield will continue to spread over New York and into Vermont early this morning as the low lifts along the St Lawrence Valley before shifting eastward just north of the international border. There are still some indications that one this first round of rain moves through, precipitation will turn more showery in nature with some spots getting a bit of a break around mid morning. Meanwhile, a 55+ kt 850 mb jet, currently moving into the eastern Great Lakes, will also make its way to our area. There's still some question how much of this will be able to mix to the ground as it will be somewhat coincident with the steadier rain, especially in northern New York. However, it will at least allow temperatures to surge into the upper 50s/low 60s. Mountain summits will be very windy as well, with gusts to 60 mph expected. Gusts will also likely be strong in the Champlain Valley and the northern slopes of the Greens, due to funneling down the valley and downsloping off the higher terrain. The aforementioned dry break could coincide with the jet's arrival at these areas, so mixing could be better as well. Hence still anticipate gusts up to 40 mph in these locations, with perhaps some briefly higher gusts at times. This could be enough to bring a few branches down, perhaps resulting in isolated power outages, but widespread impacts are not expected at this time. Elsewhere, gusts will remain in the 25 to 35 mph range.
The low moves to our north by mid day, dragging its attendant cold front across northern New York and Vermont during the afternoon and early evening. The latest CAM guidance shows convective showers developing ahead of/along this front as it pushes southeastward. We'll have little to no instability given the early morning rainfall, so anticipate showers won't be organized or strong/severe in our area. Still, there may be a few rumbles of thunder, especially in southern Vermont. Total rainfall through the daylight hours today will be 0.50 to 1.0 inch, with locally higher amounts in the higher terrain.
Winds will turn to the northwest behind the cold front, ushering in a much colder airmass. Moisture will linger for a time overnight, and the northwest flow will cause showers to focus on the favored western upslope sides of the Adirondacks and northern/central Greens. Rain will gradually transition to snow as temperatures fall overnight. Showers should wane in coverage through the night and especially Saturday morning as drier air works in behind a secondary front, coming to an end by afternoon. Between the brief timing of snow and the relatively warm ground, snow accumulations will be minimal and mainly confined to elevations above 1500 ft. Even there, accumulations will likely be half inch or less. The highest summits could see upwards of 2 inches or so.
Saturday will be much colder, with highs only in the mid 30s to mid 40s. Sun should start to break out in the afternoon, but winds will remain brisk, with gusts 25 to 30 mph. The morning will start out with wind chills in the teens and 20s; the summits will likely feel like the single digits in the morning, with negative numbers possible. These wind chills improve only slightly through the day, so anyone who has outdoor plans should prepare for bitterly cold conditions.
KEY MESSAGE 2: South to southwest flow will resume on Sunday, and we will moderate closer to seasonal norms with widespread 50s for highs under high pressure. This high pressure should shift north and east, then to start the work week, another high pressure over Quebec will dive southeastward into northern New England and the southern Canadian Maritimes, keeping our forecast area dry. Ahead of a weak back door cold front, daytime temperatures will be in the upper 50s and lower 60s Tuesday, decreasing slightly for the second half of the week. Nighttime temperatures next week fall into the mid 20s to lower 40s. Fire weather concerns will increase next week due to the long duration of dry weather anticipated, but winds will remain mostly light and terrain driven under high pressure.
Aviation /06Z Friday Through Tuesday/
Through 06Z Saturday...Rainfall and gusty winds are expected to arrive from west to east throughout next few hours, with rain starting at MSS and SLK around 06Z-08Z Friday, then PBG, BTV, and RUT 07Z-09Z, then everywhere else by 08Z-10Z. Rain is likely to cause visibilities 3-6 miles or higher, though heavier periods are possible this morning. Winds will become strong aloft first (southerly to southwesterly 30-50 knots), making LLWS likely at all sites through 18Z-23Z Friday. Surface winds will begin to gust 10-30 knots around 08Z-12Z, initially out of the south-southeast, then turning west-southwesterly this afternoon, with most sites seeing a switch to northwesterly in the evening and overnight hours. Strongest surface winds (30-35 knots) are expected across the Champlain Valley from 10Z through 20Z Friday out of the south. Cloud ceilings are also anticipated to lower throughout the next few hours, and we should see widespread MVFR or lower cigs by 10Z-13Z Friday, lasting through the end of the 24 hour TAF period. Most sites could see some brief off and on IFR cigs throughout the day Friday, but most likely spots for persistent IFR cigs include SLK, MPV, RUT, and MSS from 10Z through 20Z Friday. And lastly, around 02Z-04Z Saturday, temperatures should drop enough at SLK to see a rain snow mix for a few hours, likely becoming all snow later in the night into early Saturday morning. Rain snow mix or even just snow is also possible at EFK and MPV later in the night into early Saturday morning. At other sites, we can expect precipitation to end throughout the evening and overnight hours.
Outlook...
Saturday: VFR. Slight chance SHSN. Saturday Night: VFR. NO SIG WX. Sunday: VFR. NO SIG WX. Sunday Night: VFR. NO SIG WX. Monday: VFR. NO SIG WX. Monday Night: VFR. NO SIG WX. Tuesday: VFR. NO SIG WX.
Marine
A Lake Wind Advisory remains in effect for Lake Champlain today. South winds will increase early this morning, becoming 15 to 30 knots with gusts to 35 knots. Locally higher gusts possible. Winds will turn to the northwest and lessen somewhat after a cold front moves through later this afternoon, but the Lake Wind Advisory will likely need to remain in place through Saturday.
Climate
Daily low maximum temperatures will likely be broken on Saturday. Current records at some climate sites in our region are as follows:
Record Low Maximum Temperatures:
October 17: KBTV: 42/1970 KPBG: 44/2015 KSLK: 36/1970
Btv Watches/Warnings/Advisories
VT...None. NY...None.
WHAT HAS CHANGED...Hastings DISCUSSION...Hastings/Storm/Taber AVIATION...Storm MARINE...NWS BTV CLIMATE...NWS BTV