Area forecast discussion National Weather Service Albany New York 958 PM EDT Friday may 24 2013 Synopsis... an upper level low and surface low pressure off the New England coast will promote cool and showery weather for much of the weekend. High pressure will build across the northeast for the latter half of Memorial Day weekend and early next week...bringing a return of warmer weather. && Near term /until 6 am Saturday morning/... as of 955 PM EDT...rain continues to impact most of the forecast area especially areas north and west of the immediate capital region. North to northwesterly winds at the surface will continue to reinstate chilly temperatures during the overnight period. Low temperatures were adjusted slightly especially over the Catskills where observations in the highest elevations where already in the upper 30s and even some values in the middle 30s. However...as the cold air advection becomes less dominant throughout the overnight into tomorrow morning...we do not expect temperatures to drop much further. Favorable qg dynamics will overspread the region overnight as the upper low obtains a slightly negative tilt with height. Meanwhile at the surface...the coastal low pressure system will helping to transport Atlantic moisture back westward across the forecast area via a cold conveyor belt. The combination of these two synoptic features will allow for rain to continue through the overnight period. Quantitative precipitation forecast amounts will generally be around a quarter to half an inch...with rainfall rates again around a tenth of an inch per hour. && Short term /6 am Saturday morning through Monday night/... the 12z model suite continues to remain in good agreement handling the progression/evolution of the upper-level low/coastal low pressure system across the northeast. Have largely taken a blended approach during this time frame...leaning towards the 12z GFS/ECMWF. Saturday through Sunday morning...as the upper-level low maintains a negative tilt Saturday...coastal cyclogenesis will take place off the Massachusetts coast aided by a weak pv lobe and favorable qg dynamics. These two features will act in tandem to enhance isentropic lift associated with a cold conveyor belt. This conveyor belt will help throw back Atlantic moisture across the forecast area and promote occasional showers Saturday into Saturday night with the greatest coverage north and east of the capital district. The upper-level low will slowly drift eastward Saturday night...becoming vertically-stacked with the coastal low. These features will lift out of the region for Sunday...with some lingering showers through early Sunday afternoon with the threat diminishing from west to east. Quantitative precipitation forecast amounts through Sunday morning will range from half an inch in western portions of the Adirondacks to two inches across locations north and east of the greater capital district. See the Hydro section below for additional details. The Memorial Day weekend will not be a complete washout however...as high pressure will build across the region for late Sunday and into Memorial Day with clearing skies and dry weather. Temperatures Saturday will feel more like November as highs struggle to make it into the middle 50s. Temperatures will begin to moderate Sunday with highs in in the upper 50s to middle 60s. Highs will return to seasonable levels for Memorial Day generally in low 60s to low 70s. Lows during the short term period will generally range from the low 30s to low 40s. Winds will be breezy during the weekend...as a tight pressure gradient remains across the forecast area. Winds Saturday and Sunday will be northwesterly around 10-20 miles per hour with gusts up to 30 miles per hour before diminishing to 5-10 miles per hour for Monday. With low temperatures around or slightly below freezing in portions of the Adirondacks Saturday and Sunday night...frost advisories may be needed and will highlight this in the severe weather potential statement at this time. && Long term /Tuesday through Friday/... the long term period will feature a warming trend with a return to seasonable temperatures at the start...and eventually well above normal temperatures by the end of the work week. Surface high pressure will be over the region Monday night into Tuesday with mainly clear skies. Still cool Monday night with lows in the upper 30s to middle 40s...but temperatures Tuesday will be near normal with highs in the upper 60s to middle 70s. The high will drift offshore Tuesday night and Wednesday as a warm front approaches from the west. This will result in an increase in clouds with the chance of showers and thunderstorms Wednesday and Wednesday night...decreasing to a slight chance of showers/thunderstorms Thursday as the warm front lifts to the northeast. Fair and very warm weather expected Thursday night and Friday as upper level ridging takes hold. Lows Tuesday night will be in the upper 40s to middle 50s. Highs Wednesday in the low or middle 70s. Lows Wednesday night 50 to 60. Highs Thursday in the upper 70s to lower 80s. Lows Thursday night in the middle 50s to lower 60s...and highs Friday in the upper 70s to middle 80s. && Aviation /02z Saturday through Wednesday/... rain has increased in coverage this evening as low pressure settles in over coastal New England. A moist flow will continue to provide rainfall overnight to all of the terminals. Flying conditions predominantly expected to be MVFR...although there will be some periods of IFR possible especially when persistent moderate rain falls. Conditions will be difficult to determine after 06z and into much of Saturday as borderline MVFR/IFR conditions are expected. Will mention MVFR for now with time for refinement in subsequent taf issuances. Occasional rain will continue through Saturday...with low pressure remaining stationary along the New England coast. Winds will generally be north-northwest at around 10 knots with gusts of 15 to 20 knots...then becoming steady around 10 knots overnight. Winds will then increase to 12 to 20 kts with gusts around 25 to 30 kts due to low pressure strengthening. Outlook... Sat night-sun...VFR/MVFR...chc -shra. Breezy north winds. Sun night-Tue...VFR. No sig weather. Wednesday...VFR. MVFR possible with chance PM shra/tsra. && Fire weather... no fire weather concerns for the next five days... An upper-level low and surface low pressure off the New England coast will promote showers Saturday into Sunday. High pressure will build into the region late Sunday through Tuesday. There will be an additional chance of showers/thunderstorms during the middle of next week. Winds will be northwesterly and gusty Saturday and Sunday generally 10-20 miles per hour with gusts up to 30 miles per hour before diminishing to 5-10 miles per hour early next week. Relative humidity levels during the next five days will be above 30 percent...with relative humidity levels during Saturday and Sunday afternoon between 60-80 percent and normal overnight recoveries between 80-100 percent. Relative humidity levels Monday and Tuesday will be in the 35-55 percent range with normal overnight recoveries between 80-100 percent. && Hydrology... an upper-level low and surface low pressure off the New England coast will provide the focus for stratiform rain through Sunday morning that will bring a half inch to two inches of rainfall across the region...with the greatest amounts north and east. Although this rainfall will come on already saturated soils from recent heavy/torrential rainfall over the past couple of days...rainfall rates of only around a tenth of an inch per hour will allow local watersheds enough time to recover with only modest within bank rises. && Aly watches/warnings/advisories... CT...none. New York...none. Massachusetts...none. Vermont...none. && $$ Synopsis...irl near term...irl/lfm/jpv short term...irl long term...gjm aviation...jpv fire weather...irl hydrology...Snyder