textproduct: Binghamton

WHAT HAS CHANGED

Minor adjustments to PoPs, QPF and the light snow amounts were made for the shortwave that moves through tonight into early Saturday morning. Minor increases to PoPs along and north of I-90 Sunday night with the next weak clipper system. Still uncertainty with the Wednesday system in regards to temperatures and precipitation type.

KEY MESSAGES

1) A weak, fast moving clipper system moves through tonight into early Saturday bringing light snow and snow showers to the area.

2) Temperatures trend warmer through the weekend with a slight chance for snow showers or flurries Sunday night for northern portion of Central NY and also NE PA.

3) Temperatures will continue to trend warmer early to midweek, but then trend cooler toward the end of next week. A system moves through Wednesday with rain, snow and a wintry mix possible.

DISCUSSION

KEY MESSAGE 1...

A weak shortwave system will drop in from the north tonight. The track remains consistent in the latest guidance today. Used a blend of the latest HRRR, 3km NAM, WPC and NBM for PoPs, QPF and snow amounts tonight into Saturday morning.

NBM guidance seemed a little too low with PoPs, even with the progression of the CAMs, so PoPs were manually updated using the latest CAMs guidance for the overnight hours. This seemed a bit more reasonable and did not dry out conditions as this system dropped further south into NEPA. The NBM/Conshort blend plus WPC guidance were used for QPF to increase coverage of potential snowfall accumulations. There will be some moisture with this system, so by Saturday morning, some locations will see 0.5 to 2 inches (locally up to 3" possible). The highest totals will be across the eastern Finger Lakes, northern Susquehanna region, Syracuse metro area and NW Oneida county where 1-3 inches is expected. Elsewhere, less than an inch is expected.

KEY MESSAGE 2...

Temperatures will trend warmer through the weekend, climbing into the upper 30s and even lower 40s by Sunday. Overnight lows follow a similar trend with 20s expected Sunday night.

Behind the departure of tonight's system, west-northwest flow over Lake Ontario & Finger Lakes will likely kick off light lake effect snow showers and flurries that linger into Saturday morning. High pressure and drier air should help cut off any lingering snow showers by Saturday afternoon or Saturday night. It will remain cloudy to mostly cloudy all day Saturday for most of the area.

The remainder of the weekend is trending drier with high pressure in place. It will be partly sunny Sunday, with a light south wind and seasonably mild temperatures in place.

There will be a low that moves across the Southeast Sunday night but remains south of the region (except a slight chance for flurries in NE PA). There is also a weak wave to the north that clips northern NY. Both of these systems could just clip the region with light snow showers or flurries but would not amount to much.

KEY MESSAGE 3...

Temperatures will trend warmer through midweek, but how much so remains somewhat uncertain. While it initially looked like a ridge would set up over part of eastern CONUS, models are trending to a more zonal pattern. This would favor cooler air occasionally dipping back south over parts or all of the region. With that said, Monday is still on track to reach the low to mid-40s and Tuesday will be well into the 40s and perhaps even around 50 in the valleys of the Southern Tier and NE PA. Skies will be partly sunny both days, with dry weather expected. Overnight lows still look to dip down into the upper 20s to low 30s for most locations, which will slow the snow melt overnight and in the early morning.

Then midweek, a low moves across the Midwest with a frontal boundary extending well east over our area. There remains uncertainties with this system, though depending on the where the front sets up, this would be favorable for a wintry mix or snow that could possibly include localized freezing rain. The 12z ECMWF continues to be much colder and snowier with the Wednesday system compared to the 12z GFS and 12z CMC model guidance. The official forecast follows the ensemble/NBM guidance at this point in time, to account for uncertainty in temperatures and precipitation type with this system.

Behind this system, colder air dips south as temperatures trend slightly cooler from the peak warmth earlier in the week.

As conditions warm, we will need to keep a close eye on the rivers and streams. Warming temperatures will help melt snow but of there is any rain as well, there could be enough runoff to dislodge ice leading to additional ice jams.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

Mostly VFR conditions this afternoon south of the I90 corridor. SYR and RME are seeing some lake enhanced clouds and snow showers with westerly flow coming off Lake Ontario. There is a good chance that VFR conditions return later this afternoon and evening though, before the next disturbance comes in later tonight. That weak disturbance will move into western NY by 2 or 3Z and push from NW to SE across the region. This will bring some light snow and possible IFR to RME, SYR, ITH and BGM and at least MVFR restrictions for ELM through the overnight hours. AVP should be far enough south to remain mostly VFR through the period.

Tomorrow, lake effect snow showers could cause further restrictions through the morning hours at SYR, RME, ITH and BGM.

Outlook...

Saturday afternoon through night... Lake effect snow possible through Sat, impacting CNY with associated restrictions.

Sunday...Mainly VFR.

Sunday night... Weak clipper system could bring snow showers with associated restrictions.

Monday through Wednesday...Mainly VFR, possible restrictions late Tuesday night into Wednesday with rain or wintry mix.

BGM WATCHES/WARNINGS/ADVISORIES

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