000 FXUS61 KALY 250756 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 356 AM EDT Sun Oct 25 2020 .SYNOPSIS... Dry and chilly conditions in store through today. The start of the new week will be unsettled and cool with bouts of mainly light rain across much of the area, with some brief and light wet snow possible for the southern Adirondacks and southern Green Mountains early Monday morning. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 356 AM EDT...Still dealing with some upslope stratus clouds over parts of the Adirondacks and southern Green Mountains early this morning, although the rest of the area has mostly clear to partly cloudy skies. Expecting the clouds over the mountains to gradually dissipate this morning, as high pressure tracks eastward into southern Quebec providing a drier northerly flow. Elsewhere, just some high level cirrus clouds will move across the area today. The clouds should be relatively thin such that skies will average mostly sunny. It will be a cool day, with high temperatures running about 5-8 degrees below normal (lower/mid 40s mountains and upper 40s to lower 50s valleys). && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... Clouds will rapidly increase this evening as 850 mb flow becomes southerly, with southwest flow aloft. A 1030 mb anticyclone centered over Maine will only track slightly eastward to the Canadian Maritimes overnight. The anticyclone will provide a cold northeast low level flow into our region until slightly warmer air advects in Monday morning. Increasing isentropic lift on the 290-295K surface will result in precipitation developing gradually from southwest to northeast across the region. The precip looks to be more spotty from around Albany eastward through Sunday night. Thermal profiles cold enough for a brief period light snow or rain/snow mix across the higher terrain of the southern Adirondacks and southern Green Mountains into early Monday morning. NAM forecast soundings show a mainly isothermal profile, although some slight warming aloft around 0C to +2C could lead to some brief/light sleet too. Outside of the southern Adirondacks and southern Greens it will just be plain cold rain for most of the region. Occasional rain will persist through much of Monday, especially across the northwest half of the area, as isentropic lift continues with a weak surface wave of low pressure moves eastward across the region. With a S-SW flow aloft, warm advection will result in any light snow or sleet mix across the southern Adirondacks and southern Greens to change to rain by mid/late morning. Total snow/sleet expected to only around a dusting to just less than an inch. QPF still favors greatest amounts (0.5" to 0.75") across favored upslope areas of the SW Adirondacks, with 0.25" to 0.50" across the rest of the northern half of the region. Areas from around the Capital District southward should have < 0.25". Cool and damp conditions with clouds/rain will make for a rather dreary day. Highs only expected to reach the mid to upper 40s north of the Capital District, with lower/mid 50s from Albany south. Mostly cloudy and cool conditions will persist Monday night, as the weak wave of low pressure and a boundary shift south/east of our region with high pressure building eastward across southeast Canada. Not much forcing for precip, but low levels will remain moist, so will mention slight/low chance for showers. A few snowflakes may mix in across the Adirondacks, but with no accumulation expected. Another cool day expected for Tuesday, with cold advection occurring through the day. Temperatures will be around 5-10 degrees below normal. Low level moisture expected to persist, but again very little in the way of forcing. So have lowered pops to slight chance, although we are still expecting mostly cloudy skies. Depending on how much drier air can filter in, there could be a few breaks of sun in some spots. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... The long term period may consist of a period of unsettled weather, especially on Thursday and Friday, with generally dry weather during the other time periods. Temperatures will average below normal during this period as well. During Tuesday night, the frontal boundary will be to the south of the area; however, a few lingering showers (and higher elevation snow showers) will be possible as the upper-level shortwave passes through. Even if there were to be a few snow showers, little if any accumulation is expected. Lows will range from the upper 20s across the Adirondacks to near 40 in the mid-Hudson Valley. Upper-level flow becomes more zonal on Wednesday as high pressure works into the region. This should bring a mostly dry day with at least partial sunshine. Highs will generally reach the 40s across areas above 1000 feet to the 50s below. Thursday and Friday will be a challenging forecast for the next several days as multiple features are likely to impact the forecast. This includes 1) A southern stream cut-off upper-level low across Texas, 2) A developing tropical low moving northward into the Gulf Coast states, 3) A northern stream upper-level shortwave moving across the Great Lakes and Northeast and 4) A large area of high pressure building into the region in the wake of the northern stream shortwave, which will attempt to suppress precipitation southward. Model guidance today suggests that the upper-level low and the tropical low merge across the Southern states and track northeastward toward our region, with the center passing by to our south across the mid-Atlantic. Still, enough moisture on the northern side can bring periods of rain to the area Thursday into Friday, especially south of Albany. Pending on when precipitation ends, low-level cold air from the building high to the north could lead to a change over to a rain/snow mix or plain snow in some places before ending (this would most likely occur during the Thursday night/early Friday morning time period). It is important to note that model guidance and consistency remains low, so changes to this forecast are likely to occur in the coming days. We will continue to monitor trends and update as needed. Highs Thursday will be in the 40s and 50s with lows Thursday night in the upper 20s to near 40. Highs Friday will only reach the 30s in the higher terrain to the 40s elsewhere with lows Friday night in the 20s to lower 30s. Dry weather returns Saturday with high pressure overhead. Highs will be in the 40s to lower 50s. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... VFR conditions will persist through the end of the TAF cycle. Given that surface winds remain west-northwest with GOES16 nighttime fog channel showing MVFR stratus in place over the North Country and parts of the Berkshires, we included a TEMPO group for potential brief near MVFR ceilings at PSF and GFL mainly 06 UTC to 10 UTC. By 12 UTC, the surface winds should become oriented out of the north-northwest which should dry out the low-levels and maintain VFR ceilings through the day. Clouds thicken this evening ahead of some showers approaching from the mid-Atlantic which should result in ceilings dropping to 6-9kft at POU first with PSF and ALB following towards the end of the TAF cycle. Some light showers falling from a mid- level cloud deck may reach POU towards 03 UTC. ALB and PSF may also see some light showers by the end of the period but did not have enough confidence to include at this point. West-northwest winds ranging 5-8kts tonight become northerly this morning near 5kts before shifting to the northeast and remaining near 5kts. Outlook... Sunday Night: Moderate Operational Impact. Likely RA. Monday: High Operational Impact. Likely RA. Monday Night: Moderate Operational Impact. Chance of SHRA. Tuesday: Low Operational Impact. Slight Chance of SHRA. Tuesday Night: Low Operational Impact. Slight Chance of SHRA. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: Low Operational Impact. Slight Chance of SHRA. Thursday: Moderate Operational Impact. Chance of SHRA. && .FIRE WEATHER... Dry and chilly conditions in store through today. The start of the new week will be unsettled and cool with bouts of mainly light rain across much of the area, with some brief and light wet snow possible for the southern Adirondacks and southern Green Mountains early Monday morning. Minimum relative humidity values this afternoon will be around 40 to 50 percent. RH values will increase to between 85 and 100 percent tonight, decreasing to minimum values of only 80 to 90 percent on Monday. Winds today will be north-northeast around 5 to 10 mph, becoming easterly tonight. Winds on Monday will be southeast around 5 to 10 mph. && .HYDROLOGY... Drier and cooler conditions are forecast through today. Then some periods of mainly light rain are expected tonight into Tuesday, as a series of low pressure systems moves across the region. Total rainfall looks to be between a quarter inch and one inch, with the higher amounts north/west of Albany. This rainfall will not cause any hydro problems and will be beneficial for areas that are in D0, D1 and D2 drought categories. A stronger storm system may affect the region late in the week, with possible widespread precipitation. However, there is much uncertainty as to the evolution and track of this system, which will have a large impact on precip amounts. We will continue to monitor trends over the next several days. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...JPV NEAR TERM...JPV SHORT TERM...JPV LONG TERM...Rathbun AVIATION...Speciale FIRE WEATHER...JPV HYDROLOGY...JPV