900 FXUS61 KALY 082345 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 745 PM EDT Fri Oct 8 2021 .SYNOPSIS... A weak cold front will move westward across the region tonight. No precipitation is expected however the boundary will usher in a cooler, more seasonable airmass in for the weekend. There will be chances for some showers Sunday mainly south and east of the Capital District as a low along the coast approaches from the south. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Updated at 745 pm. Light southeast flow around the edge of high pressure centered over the Candadian maritimes will bring in increasing amounts of low level moisture overnight. Sct-bkn clouds between about 3000 and 6000 feet have been trying to form over southern New England and southeast NY early this evening and these clouds should thicken and move north overnight. These clouds should keep widespread dense fog from forming the Hudson Valley late tonight, although a few patches could still develop in any areas that see breaks in the clouds. Also, a period of fog could develop at GFL during the late evening through early morning hours before the clouds move in from the south. Lows tonight will be mainly in the 50s, with some 40s over higher terrain and across the north country. Previous discussion is below. Another mild and pleasant afternoon across the area with highs mainly in the lower 70s with any upper 60s across the higher terrain. The surface high centered to our northeast will strengthen tonight helping to push a weak cold front westward across the region. A light onshore flow will develop overnight. Aloft, the upper ridge axis will weaken slightly as it shifts eastward. With low level moisture still present and the boundary approaching and moving through expect an increase in clouds tonight. It will be another mild night for early October with lows expected to be in the lower to mid 50s below 1500 feet and in the 40s across the higher terrain. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... The surface high will hold fairly steady on Saturday and will weaken some across the region as it begins to retreat Saturday night. ALoft, the upper ridge will weaken with a short wave trough dampening out as it encounters the ridge as it passes to our northwest. Looking at cooler day with plenty of clouds with an onshore flow. Expecting seasonable highs in the 60s below 1500 feet and in the 50s across the higher terrain. Along the Southeast Coast a weak low will develop this weekend. Initially the low will not move north Saturday due to the strong high, it will wobble along the coast. With the high weakening Sunday the low will be able make progress northward bringing chances for some showers to areas mainly south and east of the Capital District mainly during the day Sunday into Sunday evening. Highs Sunday will be similar to Saturday's. Nights will continue to be mild for early October with lows in the 40s and 50s. && .LONG TERM /MONDAY THROUGH FRIDAY/... The main story for the long term period will be temperatures running a few to several degrees above normal each day. An upper-level disturbance may bring a chance for a few showers Tuesday afternoon into Wednesday, but otherwise much of the long term will remain mostly dry. Details below... The long term period begins Monday with a surface high to the east and a ridge building in aloft. These two features will keep us dry through the day Monday outside of a leftover shower or two for southeastern areas Monday morning. The surface high to the east will result in easterly low-level flow, especially for our New England areas Monday. BUFKIT model soundings suggest that this will lead to moisture becoming trapped below a mid-level subsidence inversion, so skies will likely remain partly to mostly cloudy. This should help keep temperatures a bit colder than they otherwise would be (again, mainly for New England areas). For the eastern half of our cwa, went near NBM guidance, but went a couple degrees warmer further to the west where low-level flow will be more southerly. Highs will generally be in the upper 60s (high terrain) to mid 70s (valleys). Monday night, we will still be under the influence of high pressure and ridging aloft, although there is some uncertainty as to the exact location and strength of the surface high. If the surface high remains east of our area, then lows will likely be in the low/mid 50s as suggested by the NBM. If the surface high retrogrades westward as the Euro suggests, then lows may be a few degrees cooler than the NBM guidance which was used to populate the grids. Tuesday and Tuesday Night...Models are generally in decent agreement as to the large-scale pattern, but there is still some uncertainty in the finer details. We begin Tuesday with a ridge axis over the region and an anomalously warm airmass with 850 mb temperatures of around +15C, which is around 10 degrees above normal. Therefore, blended in the NBM 90th percentile temperatures for daytime highs. Expecting upper 60s even for the high terrain with mid-upper 70s in the valleys. Guidance disagrees as to how fast the ridge moves eastward, however. The typically more progressive GFS brings a shortwave eastward from the Great Lakes region Tuesday afternoon, although the Euro doesn't bring this feature through until later Tuesday night. Therefore, will go with slight chance to chance PoPs during this timeframe and will iron out the timing as we get closer. Tuesday night will feature more clouds with lows only in the 50s even for the higher elevations. Wednesday through Friday...General consensus in the guidance is that upper-level ridging builds in from the west once again as the upper- level shortwave departs late Tuesday night or Wednesday morning with surface high pressure also building in from the west. A weak cold front will pass through the region sometime Wednesday, and we will see colder air advection into the region with winds becoming more northwesterly. Daytime highs will be cooler than Tuesday, but will still be in the low 60s (high terrain) to mid 70s (valleys), which is still several degrees above normal. Wednesday night through Friday, we will remain under the upper-level ridge with continued dry weather and anomalously warm temperatures. Went near NBM guidance for daytime highs due to the long lead time, but it is not out of the question that highs will remain warmer than the current forecast for the Thursday and Friday time period. AS we get towards the end of the week, we will also be watching a large upper-level trough to the west of our area. The GFS brings this trough close enough to see some showers Friday, although the Euro is a bit slower and drier. Current thinking is more in line with the Euro given the relatively amplified flow regime, but did include slight chance to chance PoPs for our western areas given the long lead time. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... Clouds with areas of MVFR cigs will increase through tonight. Cloud development should keep fog from being as widespread and dense in the Hudson Valley tonight as the previous couple of nights, but there could still be some patches of mainly MVFR vsbys if and when any breaks occur which would allow for some small areas of fog to develop. Cigs will slowly lift during the day Saturday with heights around 3000 feet by afternoon. Winds will be light and variable tonight, southeast at less than 10 kts Saturday. Outlook... Saturday Night: Low Operational Impact. NO SIG WX. Sunday: Low Operational Impact. Slight Chance of SHRA. Sunday Night: Low Operational Impact. Slight Chance of SHRA. Columbus Day: No Operational Impact. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: Low Operational Impact. NO SIG WX. Tuesday Night: Low Operational Impact. Slight Chance of SHRA. Wednesday: Low Operational Impact. Slight Chance of SHRA. && .FIRE WEATHER... A weak cold front will move westward across the region tonight. No precipitation is expected however the boundary will usher in a cooler, more seasonable airmass in for the weekend. There will be chances for some showers Sunday mainly south and east of the Capital District as a low along the coast approaches from the south. Minimum relative humidity levels Saturday afternoon are expected to be in the mid 60s to mid 70s with higher values on Sunday. An onshore, easterly flow will develop and persist through the weekend. && .HYDROLOGY... No hydrologic problems anticipated over the next several days with mainly fair weather expected. Some showers are possible Sunday into Sunday night mainly south and east of the Capital District, as a coastal storm approaches from the Mid Atlantic region. However, it appears this system should stay far enough away to only produce light QPF amounts at best. Next chances for any showers are expected Tuesday night mainly across the southern Adirondacks and Mohawk Valley. 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...IAA NEAR TERM...IAA/MSE SHORT TERM...IAA LONG TERM...Main AVIATION...MSE FIRE WEATHER...IAA HYDROLOGY...IAA