textproduct: Binghamton

WHAT HAS CHANGED

Adjustments were made to temperatures Thursday night and Friday. Some localized areas of patchy frost were added for Thursday night.

KEY MESSAGES

1) A passing cold front this afternoon brings falling temperatures and scattered showers and thunderstorms this afternoon. Rain continues into Thursday before high pressure builds in later in the day.

2) Rain returns for much of the holiday weekend as temperatures remain below normal. High pressure then returns early next week with warmer and drier conditions.

DISCUSSION

KEY MESSAGE 1...

A cold front continues to move through the region this afternoon and evening. Shower activity is beginning to pop up along the front in PA's Northern Tier. Further south from there, clear skies have led to much warmer conditions, allowing for a more unstable environment with 500+ J/kg of MLCAPE. Shear is weak at just 25 to 30 knots. In addition, while the low-level lapse rates are steep, the mid-level lapse rates are modest at best. Overall, the concern for stronger storms remains low but there is still a need to monitor these areas this afternoon, especially the Wyoming Valley and along the I-84 corridor.

Heading into the evening, conditions will become more stable though rain will continue. This front will drop south of the region overnight but will stall before reaching the coast. An incoming wave will also pass through the region overnight. These two features will interact as a plume of moisture remains along the stalled front. This will kick off additional showers late tonight/early Thursday morning with rain continuing through at least midday for portions of NEPA. There is some uncertainty on how long the rain sticks around as the CAMs move the rain out by early afternoon while the operational and AI versions of the global models keep the rain into the afternoon hours. For now, this forecast leaned toward the short- range guidance but additional timing adjustments may be needed in future updates. Temperatures will continue to fall behind the front with low in the 40s to low 50s tonight.

High pressure will build into the region late Thursday and remain present through at least Friday. This will bring a dry end to the workweek but temperatures will be near or below average for this time of year. For Thursday, temperatures only climb into the 50s and 60s before falling into the 30s and 40s Thursday night. For this update, temperatures were bumped down below NBM guidance by blending in the NBM tenth percentile as clear skies should result in efficient radiational cooling. Frost was also added for small areas in Oneida and Steuben county where temps will be near the mid 30s. A slight warm up is then expected Friday. However, a cold air damming set up and increasing cloud cover will likely keep most of the region in the 60s during the day. Additional adjustments were made to the forecast during this time. While all areas were lowered below guidance, the lower elevations were kept more mild where probabilities are higher for 70+ degree high temperatures.

KEY MESSAGE 2...

A low pressure system will drift north into the Great Lake region and bring the next round of rain Friday night into Saturday. This system is fairly slow moving resulting in rain likely continuing through at least Saturday night but potentially longer. WPC has the region in a Marginal Risk for Excessive Rainfall. PWATs will be 1.25 to 1.5 inches which is about 2 standard deviations above normal. Models are showing a corridor of 1 to 2 inches of accumulation over a 24-hour period though there is uncertainty where this will be. Precipitation this week has been localized and there will be a couple of dry days leading up to this weekend, so hydro concerns are minimal at this time.

There will be a brief lull in shower activity before the next round moves in on Sunday. While some guidance have conditions beginning to dry out on Monday, it might be too little too late to enjoy any part of the holiday weekend as rain will likely linger through most of the daytime hours. High pressure will eventually build into the region Monday night, bringing drier conditions. This high pressure will then remain present over the region through at least midweek. A couple of stray showers cannot be ruled out as systems may clip the region but for most, conditions will stay dry. Temperatures will trend warmer early next week, returning closer to near if not slightly warmer than normal.

AVIATION /00Z THURSDAY THROUGH MONDAY/

The cold front has moved through the region with some lingering rain at AVP that will clear by 0Z so it was omitted from this set of TAFs. High clouds are going to continue to stream overhead tonight through tomorrow so while it will remain cloudy, cigs will be VFR at all terminals through 0Z tomorrow.

AVP has a chance at seeing some sprinkles late tonight into tomorrow morning. Cigs remain VFR with dry air in the low levels but brief MVFR vis is possible if the rain could get heavy enough. Every other terminal will remain dry over the next 24 hours.

Outlook:

Thursday afternoon through Friday...Mainly VFR.

Friday night through Sunday...Periods of rain and embedded thunderstorms likely along with associated restrictions.

BGM WATCHES/WARNINGS/ADVISORIES

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