textproduct: Binghamton

WHAT HAS CHANGED

Increased cloud cover over the region today, and also increased chances for rain this morning across portions of the Wyoming Valley and Poconos. Issued a frost advisory for portions of Central NY tonight into early Friday morning, as temperatures are forecast to fall into the low to mid 30s in the colder valley locations.

KEY MESSAGES

1) Lingering showers will be across the Wyoming Valley and Poconos this morning, with mid and high level clouds overspreading much of the forecast area through the day. High pressure builds into the area tonight, with clearing skies, light winds and cold overnight lows in the 30s to low 40s. A frost advisory has been issued for Oneida, Madison, Chenango, Cortland, Otsego and Delaware counties from 11 PM this evening until 8 AM Friday morning.

2) Friday will feature high pressure, mostly sunny skies and seasonably mild temperatures. The next slow moving frontal system brings periods of rain and much cooler temperatures to kick off the upcoming weekend. Showers linger into Sunday morning, with some drying possible later in the afternoon.

3) Memorial Day will see a warming trend, but it still looks to remain mostly cloudy with scattered showers possible. Guidance shows a continued warming trend, with dry and mainly sunny conditions heading into Tuesday/Wednesday next week.

DISCUSSION

KEY MESSAGE 1...

Mid level moisture continues to stream north and east over the area north of a stalled frontal boundary. The latest MRMS regional radar loop shows a batch of showers extending from Ohio, across PA into our NE PA counties. At the same time, drier air is filtering in from the north, with a light north wind advecting in lower dew points. Kept the official forecast close to the NBM data for this morning's PoPs and QPF, but did nudge both a bit higher and further north based on radar trends and the latest HRRR/3km NAM guidance. It is still possible the steady rain makes it slightly further north (like the 03z HRRR is indicating)...and this would mean a steady light rainfall this morning across Pike, southern Wayne, Lackawanna and Luzerne counties in NE PA, along with SE Sullivan County NY. This will be monitored closely early this morning to see if any forecast adjustments may be needed. Otherwise, mid and high level clouds will stream SW to NE over the area through most of the day today; there could be some filtered sunshine especially the further north and west you are. The cloud bases are high, generally up near 20k ft AGL upstream in the Buffalo, Cleveland area. Today will see cooler temperatures with highs in the upper 50s to mid-60s expected, and a light north wind 5 to 15 mph.

High pressure build in from the north this evening and tonight. Initially the mid and high level clouds will linger across the Twin Tiers and Catskill even a few hours after sunset, but then the clouds drop south and dissipate overnight. This will lead to mainly clear conditions (except some clouds linger in the Wyoming Valley and NE PA south of I-84). Winds will be light and variable, decoupling in the valley locations. With low dew points in the 30s to low 40s, this dry air mass should allow temperatures to fall quite quickly after sunset. Lowered forecast overnight temperatures using a blend of the latest MET, MAV and NBM 10th percentile guidance. Decided to hoist a frost advisory where overnight lows dip down below 36 degrees (over a majority of the forecast zone). Again, Frost Advisories are in effect from 11 PM this evening until 8 AM Friday morning for Oneida, Madison, Chenango, Cortland, Otsego and Delaware counties where confidence was highest that many locations woulds see some frost. Across most of the rest of Central NY a mention of patchy valley frost was made in the HWO, where low temperatures may locally dip down just cold enough (35-37F) for this to occur.

KEY MESSAGE 2...

High pressure remains firmly in place across our area on Friday morning. By the afternoon hours the high pressure center begins to slide north and east, with some increasing clouds expected for portions of our area (mainly NE PA). Otherwise, Friday will be dry and mild with high temperatures in the mid-60s to lower 70s and a light east wind up to 10 mph.

Rain moves in from the south and west later Friday night and continues through much of the day on Saturday as a low pressure system tracks into the Ohio Valley. Our area will be locked in a very cool, cold air damming, easterly flow regime all day. As the rain falls, surface temperatures will cool due to wet bulbing (dew points are progged to be in 40s)...this will lead to high temperatures only in the upper 40s to mid 50s across NE PA, the Catskills and Twin Tiers. Further north, the rain may not start right away in the morning and it could reach the lower 60s for the Mohawk Valley and Syracuse metro area. Rainfall amounts look to be between about a half inch to one inch areawide Saturday into Saturday night.

By Sunday, there will be some lingering morning showers as the front pulls off to the east. The latest guidance is showing drier conditions, but still mainly cloudy and cool in the afternoon. Highs only reach the upper 50s to 60s east of I-81, with upper 60s to around 70 west of I-81 expected.

KEY MESSAGE 3...

Memorial Day still features a lot of forecast uncertainty, with the deterministic models disagreeing on the timing and placement of frontal features. For now, the official forecast will be based on the NBM/WPC ensemble guidance. This is showing a decreasing trend in PoPs, but still a chance for some scattered showers around at times. Temperatures do see the beginnings of a warming trend, reaching the low to mid-70s for highs. Guidance is in fairly good agreement that heading into the middle of next week (Tuesday/Wednesday) it will be dry, mostly sunny and warmer under upper level ridging. Current guidance brings high temperatures back into the mid-70s to lower 80s.

AVIATION /06Z THURSDAY THROUGH MONDAY/

VFR conditions are expected through the period. Only weather impacts will be that AVP has a chance at seeing some light rain showers this morning. Cigs remain VFR with dry air in the low levels, but brief MVFR vis is possible if the rain could get heavy enough, but at this time, that appears unlikely.

Outlook:

Friday...Mainly VFR.

Friday night through Monday...Periods of rain showers and embedded thunderstorms possible throughout the holiday weekend.

BGM WATCHES/WARNINGS/ADVISORIES

PA...None. NY...Frost Advisory from 11 PM this evening to 8 AM EDT Friday for NYZ009-036-037-044>046-057.