textproduct: Binghamton

WHAT HAS CHANGED

Wind advisories were allowed to expire as gusts have fallen below 40 mph. Rain showers are mostly virga so lowered QPF through tonight.

KEY MESSAGES

1) Isolated rain showers today, better chances of widespread rain tomorrow into Thursday morning.

2) A cool air mass settles into place late this week through the weekend leading to below average temperatures, scattered shower chances and the possibility for frost and/or freezes during the overnight hours.

DISCUSSION

KEY MESSAGE 1...

Dry air in place has evaporated most of the rain that is falling out of these showers moving through. Winds late this morning and early afternoon were a little stronger than forecast, which could have been helped by the virga passing overhead, leading to some evaporative cooling and steepening of the low level lapse rates helping to mix down some of those stronger gusts. A surface front is making its way through western NY and will move through our forecast area mid to late this afternoon. Better forcing and a pre moistened atmosphere should at least let some rain reach the ground.

Tonight will have a break in the precipitation between areas of low pressure, with residual moisture leading to low stratus across most of the region, with some hill and ridge top fog possible.

Tomorrow, another low pressure system moves into the Northeast, with better moisture in place. A few rain showers will try to develop late morning into the early afternoon with some instability aloft and a weak 500 mb shortwave passing through. A more robust 500 mb shortwave moves in Wednesday afternoon into the overnight hours along with the surface low. This trough does have a bit of a negative tilt to it. Rainfall rates could briefly touch an inch per hour as the trough swings through in the heavier showers but the trough is moving fast so the heavy rain wont last long in any given location.

KEY MESSAGE 2

Once the set of lows are through, then a long wave trough sets up over the northeast leading to cool north to northwest flow keeping temperatures below average Friday into early next week. 850 mb temperatures could fall to around -5C, especially overnight Friday and Saturday, which would be cold enough for snow to mix in if precipitation can persist into the overnight hours. With the cold air aloft and strong solar heating at this time of the year, instability will likely develop each afternoon with scattered showers developing. Graupel would be possible with the low freezing levels in the stronger showers. Overnight lows around freezing will lead to frost potential if skies clear for long enough and even some localized freezes. It will be dependent on low level moisture as showers could bump up dew points enough for fog development.

AVIATION /19Z TUESDAY THROUGH SUNDAY/

Fairly strong southerly winds should continue throughout the afternoon with occasional gusts in the 20-30 knot range. Some gusts as high as 35 knots have been observed. Winds taper this evening. Uncertainity increases later this evening with regards to when ceilings lower into the MVFR range, anywhere from 06-16Z. Potential is also present fort some variability between MVFR and VFR for the overnight and Wednesday morning timeframes. Clouds should limit any fog concern at KELM. A few rain showers may reach KELM,KBGM and KITH by 18Z Wednesday though more indications are for them to start just after the current TAF period.

Outlook:

Wednesday afternoon and night...A period of steadier rainfall expected, along with associated restrictions.

Thursday through Saturday...Additional isolated to scattered showers and associated restrictions possible.

BGM WATCHES/WARNINGS/ADVISORIES

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