textproduct: Binghamton

WHAT HAS CHANGED

Minor adjustments were made to snowfall totals.

KEY MESSAGES

1) Colder air from the north will allow rain to transition to snow later today into Friday.

2) Lake effect precipitation is expected for portions of the region through the weekend.

3) Temperatures will trend warmer next week as an upper level ridge builds in.

DISCUSSION

KEY MESSAGE 1...

Periods of rain will continue to impact the area this afternoon. Rainfall amounts of 1-2 inches have been observed across NE PA, and the precipitation shield continues to drift northward across the area.

With the center of the low sliding just to the south later today, colder air will begin to fill in from north allowing rain to become a rain/snow mix and eventually just snow overnight. Timing of the precipitation type transition will depend on how quickly the colder air moves in. Rain will change over to snow in the higher elevations first but most valleys should see snow by Friday morning. With surface temperatures stuck in the 30s, snow continues through much of the daytime Friday thanks to wraparound moisture on the back side of the low. As the low drifts out to sea later on Friday, coverage will become more scattered and showery in nature on the back side of the system. Meanwhile, low-level flow will advect colder air over the Great Lakes, generating lake effect snow.

Snowfall totals have been creeping upwards since the previous forecast. Higher elevations of the Catskills still could see the highest totals with localized amounts of 3+ inches. Other higher elevations across the region could see an inch or more. A coating of snow is possible elsewhere on colder surfaces but is not expected to accumulate much on the warmer ground. If rain transitions to snow quicker than expected, then final snowfall amounts could end up higher. These forecasted totals are approaching advisory level, but confidence remains too low for any headline issuance at this time.

Temperatures through the end of the work week will be colder than past days. Highs today will be in the 40s and 50s before falling to near and below freezing tonight. Temperatures will struggle to warm up Friday, only maxing out in the 30s to low 40s. Then sub-freezing temperatures are expected Friday night and this could lead to light icing on untreated, wet surfaces.

KEY MESSAGE 2...

Flow will become northwesterly and 850mb temperatures fall colder on Saturday, leading to lake effect precipitation lingering into at least Sunday. Along the northern areas of the Finger Lakes, precipitation will be primarily rain showers or a rain/snow mix due to slightly warmer conditions. Elsewhere, precipitation will be mainly snow showers, at least on Saturday.

Eventually, drier air begins to move in early next week as an upper level ridge approaches the region.

KEY MESSAGE 3...

After this brief sample of winter, weather conditions improve during the midweek period. The aforementioned ridge builds into the region Tuesday with high pressure present through at least Thursday. Temperatures will trend warmer and back above average, at least for daytime highs. The nights will remain cool with temperatures near or below freezing.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Conditions will continue to deteriorate with periods of rain and low ceilings. MVFR and eventually IFR conditions are expected through the remainder of the day.

Wet snow could begin mixing in with the rain this evening, before mostly changing over to light snow late tonight/early Friday morning. Widespread IFR restrictions are expected to remain across the area right through the end of the TAF period (at least through 18Z Friday).

Outlook...

Friday through Saturday...A mix of rain/snow showers possible and associated restrictions.

Sunday...Lingering rain and snow showers, mainly in the morning with associated restrictions possible.

Monday-Tuesday...Mainly VFR.

BGM WATCHES/WARNINGS/ADVISORIES

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