textproduct: Binghamton

WHAT HAS CHANGED

Snowfall forecast were increased slightly for higher elevations of CNY with better chances of lake effect snow tonight into Tuesday.

KEY MESSAGES

1) A cold front has passed through the region with steadily falling temperatures and chances of rain and snow showers through Tuesday.

2) High pressure and drier weather is expected mid-to-late week starting off cold mid week before moderating to seasonable temperatures by the weekend.

DISCUSSION

KEY MESSAGE 1...

With the cold front through the region, temperatures have steadily been falling and that trend will continue. Clouds are thinning a bit this afternoon and that could halt the fall of temps briefly but not for long. Tonight, as 850 mb temperatures fall to around -8C to -10C, surface temperatures fall below freezing and lake effect snow showers likely develop. Soundings tonight show just barely enough lake induced CAPE but the boundary layer is pretty shallow so lake effect snow showers will be on the lighter side tonight.

Tomorrow, a deeper pocket of colder air advects in aloft as the long wave trough axis approaches the region from the west. Cooling aloft coupled with strong solar heating at this time of the year will make for some steep lapse rates through at least 700 mb and potentially to 500 mb if there is enough heating. Thermal profiles through the day will support snow with may be a mix of rain at the lowest elevations below 800 feet with convective showers that develop in the afternoon. Some of the CAMs are trying to develop enough CAPE for a low end lightning potential and graupel in some of the stronger cells that develop. The probability of thunder is still to low to add to the grids for Monday afternoon and evening.

With the trough axis moving through on Tuesday, temperatures region wide will struggle to get above freezing with scattered snow showers as a 500 mb shortwave swings through. Given the time of the year and lack of frontogenesis for higher snowfall rates, any accumulating snow is limited to the overnight hours Monday into Tuesday morning before solar heating melts the snow that fell and any additional falling snow through the day.

KEY MESSAGE 2...

The long wave trough moves east Tuesday night with strong high pressure moving in. Despite return flow developing Tuesday night, the calm winds and clear skies leads to a very cold April morning. Lows are currently forecast to be in the low 20s and teens but conditions are favorable for good radiational cooling so there is potential for the current low forecast to be too warm.

Zonal flow and weak warm air advection helps temperatures quickly moderate Wednesday through Friday back to seasonable temperatures with cool mornings and warm afternoon highs. High pressure over the SE US helps cut off any moisture from the Gulf so chances of precipitation is low from mid week into the weekend.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

18Z Update... Steady rain has exited, and now the terminals have entered a post-frontal regime with flow from the west-northwest bringing in a 2-4 kft agl ceiling and cooler air. A minor lake effect response will also yield mixed rain-snow showers tonight, at times lightly impacting KSYR-KRME. KAVP is likely to improve to VFR later this afternoon and remain there, whereas the NY terminals will fluctuate in and out of it overnight before settling at least for a time at VFR.

Outlook:

Late Monday through midday Tuesday...A clipper system will brush by with initially mixed rain-snow showers, becoming scattered snow showers with possible restrictions, as colder air is reinforced across the area.

Late Tuesday through Thursday Night...Mainly VFR.

Friday...A weak frontal zone may encroach into the area with a chance of rain showers and associated restrictions.

BGM WATCHES/WARNINGS/ADVISORIES

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