Area forecast discussion National Weather Service Binghamton New York 810 PM EDT Sat may 25 2013 Synopsis... a northerly flow of cold air will continue over the Holiday weekend as a low moves slowly out of New England. This will make for very chilly nights...with a chance for frost or freeze in some locations, and blustery days. The flow will relax somewhat allowing for a more comfortable afternoon on Monday. && Near term /until 6 am Sunday morning/... 7 PM update... hrrr in agreement with earlier forecast that precipitation will not back its way to syr/I-81 corridor overnight. Will continue trend to very slowly push the precipitation shield eastward to the Broome/Delaware County border by 6z. Temperatures were updated to account for some late day highs being made as sun finally arrived along and west of I-81. 4 PM update... models show little mvmt in the upper low tonight and actually back the precipitation a bit this evening as a weak upper WV rotates through. This will help keep clouds in the area and the winds up...in turn helping the frost/freeze scenario. Still...it's a tough call with the winds precluding frost in most areas. However...with temperatures aprchg 32f...some parts of the central southern tier may get spotty frost in the sheltered valleys where the winds become light. Does not look like enough below freezing temperatures to warrant a freeze warning for tonight. In any case...word is out and most shd be protecting their plants. Models were in rsnbl agreement on temperatures ldg to higher confidence. Cnsdrd putting some mixed pcp in the forecast but surface temperatures where the precipitation is falling is very mrngl...plus...temps aloft really do not support any frozen due to the isothermal layer in the precipitation zone. && Short term /6 am Sunday morning through Tuesday/... upper low fnly begins to kick out on sun and any leftover precipitation shd exit the County Warning Area early. Northwest flow continues but with more sun...modification of the air mass shd begin in earnest on sun. Sun night may be a real prblm for plants with the lighter winds and very dry air in place. Will of course continue with the freeze watch and expect the upgrade to a warning as guidance indicates a wide area of upper 20s through The Heart of the forecast area. Continued imprvmt Monday after a chilly start as the high mvers ovrhd. Tuesday starts dry but will become cdy as the warm fnt approaches from the Ohio Valley. Rapidly building heights and warm air advection will help develop precipitation during tus and perhaps even some conv late. Fnt will mark the return of much warmer air for the end of the week. && Long term /Tuesday night through Saturday/... surface high is centered off the East Coast. An upper level ridge builds over the eastern US from Wednesday into Saturday causing afternoon temperatures climb through the 80s to near 90 by the weekend. Humidity will also build getting US back into the feel of Summer increasing the instability. The question is the trigger. Do we stay suppressed or does a warm front stall over northern New York with a possible northwest flow convective pattern. Used HPC grids which follow closer to the European model (ecmwf) placing the front in northern New York. Warm front passed from SW to NE across the forecast area Wednesday with a chance of showers and thunderstorms. If the front stalls in northern New York than that would be a focus for triggering storms Thursday and Friday hence a little greater pop across the north. Just to note though...the GFS stalls the front further north in Canada and instead rotates scattered convection areound the west side of the surface high up across eastern PA into southcentral New York implying that the southern part of the forecast area has a greater chance. Either way it will likely be hot and humid with a chance of showers and thunderstorms. && Aviation /00z Sunday through Thursday/... VFR conditions will persist through this taf period. Cutoff low in the Gulf of Maine will begin moving northeast and lifting into Nova Scotia on Sunday. Wrap around moisture from this system will impact krme through 05z with unrestricted light rain and ceilings around 4k feet. At ksyr/kith/kbgm/kavp, wrap around moisture will make for scattered/broken 5k feet clouds along with broken middle clouds through late evening with skies clearing between 03-05z. On Sunday scattered/broken strato cumulus will form around 5k feet. Northwest winds around 10 knots overnight increasing on Sunday to 12-15 knots with gusts around 25 knots. Outlook... Mon-Tue...VFR. Wed-Thu...VFR. Chance thunderstorms. && Bgm watches/warnings/advisories... PA...frost advisory from 2 am to 9 am EDT Sunday for paz038>040-043- 044-047-048-072. Freeze watch from late Sunday night through Monday morning for paz038>040-043-044-047-048-072. New York...frost advisory from 2 am to 9 am EDT Sunday for nyz022>025- 044>046-055>057-062. Freeze watch from late Sunday night through Monday morning for nyz009-022>025-036-037-044>046-055>057-062. && $$ Synopsis...dgm near term...dgm/djp short term...dgm long term...bmw aviation...rrm