textproduct: Binghamton

WHAT HAS CHANGED

Added in some chances for isolated to scattered pop up showers this afternoon across the western Finger Lakes, Southern Tier and portions of Northeast PA as a shortwave disturbance swings through the area. Lowered expected overnight lows tonight into Tuesday morning as model guidance shows an exceptional radiational cooling environment.

KEY MESSAGES

1) A cold air mass will linger through Tuesday, with a threat for widespread frost and freeze conditions tonight into early Tuesday morning.

2) Another trough of low pressure moves into the area on Wednesday into Thursday, keeping the cooler weather around, but with rain and clouds, temperatures will remain above freezing.

3) A pattern change heading into the upcoming weekend and early next week will allow for warmer air to return to the Northeast.

DISCUSSION

KEY MESSAGE 1...

Starting off with some high clouds around the area early this morning, along with cold temperatures and areas of frost.

Today will feature morning sunshine followed by a small chance at some afternoon pop up rain showers due to the instability generated by the strong solar heating under the cold air aloft. Overnight lows will be colder tonight as high pressure will be centered closer so radiational cooling will be more efficient. Went closer to the NBM 10th percentile for the official forecast lows. Freeze warnings may be needed for tonight into early Tuesday morning as upper 20s to low 30s are possible in portions of the Catskills, Susquehanna region and into the Twin Tiers of NY/PA. After the cold start Tuesday will feature ample sunshine through the day and nicely rebounding temperature with mid-50s to mid-60s by afternoon. There does not appear to be another frost or freeze threat after Tuesday morning for the foreseeable future in our forecast area.

KEY MESSAGE 2...

The next trough of low pressure arrives from the west Tuesday night into Wednesday. This system will have a lot more moisture to work with, and it does not have much cold air, with 850mb temperatures hovering around +2C on most model guidance. Rain will develop late Tuesday night and overspread the area. Periods of rain and/or showers will continue all day Wednesday, with a slight chance for a few thunderstorms as well. Periods of rain look to continue Wednesday night and even into Thursday as the slow moving 500mb closed low spins directly overhead. By Friday the upper level low wobbles slowly east, toward Southern New England. This may allow our area to gradually dry out, but we still cannot rule out some pop up showers, especially along and east of I-81...of course the exact timing and positioning of the upper level low could still change by day 5.

Even though there will be better moisture with this trough, with PWATs between 0.5 and 0.8 inches, so rainfall amounts will be less than a half inch for most of the region through Thursday morning, but may end up between a half inch to one inch by the time the rain showers finally end later Friday.

KEY MESSAGE 3...

Once this trough is through late Friday or Friday night 500 mb heights slowly rise and 850 mb temperatures climb back towards +10C over the weekend. Zonal flow sets up aloft with southerly flow from the gulf through the central US could mean the pattern will remain active with frequent chances of showers and thunderstorms. At least day time highs will be back into the 70s and lows in the upper 40s and 50s. Looking beyond this into early next week, there are hints that the pattern could completely flip with ensembles showing greater odds of Western US troughing and east coast ridging in the 8 to 14 day period. This could mean daytime highs pushing into the 80s for portions of Central NY and Northeast PA next Monday and/or Tuesday.

AVIATION /12Z MONDAY THROUGH FRIDAY/

VFR conditions expected through the TAF period at all terminals.

There is a slight chance for afternoon rain showers near ITH/ELM/BGM, but given low confidence in coverage they were not mentioned in the TAFs. Also, dry air in the lower levels of the atmosphere will help evaporate some of the showers before they even reach the ground.

If ELM sees some showers this afternoon, fog with IFR and lower restrictions will be possible tonight as high pressure and calm winds will prevail. Fog was not introduced into this TAF set as confidence in it occurring is low and requires rain to fall over/near the terminal.

Outlook:

Tuesday thru Tuesday evening...VFR conditions expected.

Late Tuesday night through Thursday...Showers likely with associated restrictions as low pressure pivots into the region.

Thursday night and Friday: Slow lifting and clearing of restrictions toward VFR. Timing still somewhat uncertain.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Frost Advisory until 8 AM EDT this morning for PAZ038-039. NY...Frost Advisory until 8 AM EDT this morning for NYZ009-022>025- 036-037-044>046-055>057.