textproduct: Binghamton

WHAT HAS CHANGED

The small threat for severe thunderstorms in Northeast PA this afternoon is trending more limited, though the Wyoming Valley to Poconos still have a marginal risk. There is a somewhat increasing concern that wet roads late tonight could develop patchy ice towards dawn Monday, whether or not rain ends as a mix of flurries and freezing drizzle.

KEY MESSAGES

1) Though milder today, waves of rain develop as a frontal zone drops through the region, first in Central New York and then pressing south. A few thunderstorms could occur in Northeast Pennsylvania as the front passes this afternoon to early evening, with isolated hail and gusty winds.

2) Rain may finish overnight with a brief very light mix of snow, drizzle, and perhaps a touch of freezing rain in pockets from the Twin Tiers northward. Even if precipitation ends, roads wet from prior rainfall could develop patchy ice towards dawn, potentially affecting the Monday morning commute.

3) Cool yet generally dry conditions are expected Monday into Tuesday, but Wednesday through Friday will feature waves passing through the region with temperature swings and occasional chances of precipitation.

DISCUSSION

KEY MESSAGE 1... It will be milder today as a warm frontal zone has entered the region, but this will be tempered by developing waves of rain. The front will hang up to cause a gradient in temperatures from 40s-near 50 north of the NY Thruway, to 50s-near 60 in Finger Lakes to Southern Tier NY, to mainly 60s into Pennsylvania especially the Wyoming Valley. Warm air advection will persist aloft but near surface levels will start scooping underneath to drag cooler air north to south with time. We get into the right entrance region of a jet which will keep forced ascent going on the north side of the front, resulting in anafront-style rain for much of the area. However, to the south there may be enough instability at least aloft for isolated thunderstorms in Northeast Pennsylvania. Surface-based storms appear unlikely, but a storm core or two aloft could still reach the Wyoming Valley with downpours and perhaps isolated large hail/gusty winds. High resolution model ensembles about a 40-60 percent probability of exceeding three-quarters of an inch of rain from the Wyoming Valley into the Poconos, and an isolated instance of flooding roads/poor drainage area cannot totally be ruled out there. However, otherwise quarter to half inch amounts will be more common especially from the Twin Tiers northward.

KEY MESSAGE 2... Temperatures will fall tonight behind the front, as rain gradually ends from north to south. However, a brief mix of snow-rain-drizzle and perhaps freezing rain could occur on the back side as it finishes up. Even if precipitation totally ceases though, roads will likely remain wet as readings from the Twin Tiers northward settle into the upper 20s to lower 30s towards dawn. Farther south, it will be limited more to the higher terrain. This means patchy ice may occur, impacting the early morning commute. Exposed surfaces such as bridges, overpasses, and car tops will be more prone to patchy ice.

KEY MESSAGE 3... Other than possible slick spots early, Monday will generally be dry and cool with highs of 30s to lower 40s, followed by upper teens to upper 20s Monday night. Quiet conditions continue into Tuesday with mostly sunny sky and 40s. However, the rest of the weak will remain a busier pattern with passing waves and occasional chances of precipitation. Temperatures will also bounce around, reaching well into the 50s for most of the area by Thursday, only for a showery low pressure system to pass with cooler conditions in its wake Friday-Saturday.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

Rain showers will move in from the north this morning, but with dry conditions, it may take a little time for rain to reach the ground. Showers will spread form north to south throughout the morning. Ceilings will fall throughout the day with IFR expected at all terminals this afternoon/evening. Visibilities will also be reduced at times. There is a slight chance for thunderstorms at AVP from mid-afternoon through early evening. Rain will gradually come to an end tonight though as it does, it may transition to light snow or freezing drizzle for ITH, SYR, and RME as cold air fills in. While there will also be some improvement to ceilings tonight, AVP, SYR, and RME will be the terminals that have the best chance for Fuel Alt/MVFR by the end of the TAF period.

Southerly winds will remain breezy through the daytime hours with gusts around 15 kts. As the front drops south, winds will become more northerly with sustained speeds of 5 to 10 kts. Low-level wind shear (LLWS) is possible at all terminals early this morning. At 2000 ft AGL, winds will be out of the southeast and then south-southwest with speeds of 35 to 40 kts.

Outlook:

Monday through Tuesday...High pressure building in across the Northeast with mainly VFR conditions; Possible restrictions with morning fog.

Wednesday...Cold front begins to move in from the north with rain and snow showers as well as potential restrictions.

Thursday... Warm front pushes up from the southwest with rainshowers and restrictions possible.

BGM WATCHES/WARNINGS/ADVISORIES

PA...None. NY...None.