textproduct: Binghamton

WHAT HAS CHANGED

Temperatures were reduced the rest for the rest of today where skies remain cloudy. Otherwise, there were no significant changes from the previous update.

KEY MESSAGES

1) Temperatures will trend warmer throughout much of the week, leading to an extended period of warmer than normal temperatures.

2) Rain will return midweek with additional chances for showers through the end of the week.

DISCUSSION

KEY MESSAGE 1...

Marine moisture has kept clouds around for locations along and west of I-81. This has significantly limited heating as much of the area under the clouds remain in 60s this afternoon. Where there has been sunshine, temperatures have reached the 70s. Due to this, temperatures were significantly reduced where skies have been mostly cloudy this morning resulting in afternoon highs now in the mid 70s to low 80s. Additional adjustments were made to temperatures for tonight as clear skies should once again lead to good radiational cooling. Temperatures tonight will fall into the 50s for most, though the Finger Lakes will hold onto 60s.

After today, temperatures will often be above normal as south to westerly flow will keep warm air in place for the rest of the week. A slight cool down is expected Wednesday due to showers but then temperatures will trend warmer through Friday until a cold front brings a little bit of relief for the weekend. There is uncertainty late in the week as the timing of a cold front will likely be a factor in how warm the region gets. A later timing would favor highs near or above 90 like what the NBM has. In this situation, advisories may be needed as heat index values would exceed criteria. However, an earlier timing in the day would keep temperatures a bit cooler. As with past updates, NBM guidance has been running warmer than most deterministic and ensemble guidance, so daytime temperatures were lowered below the NBM for most of the forecast period.

KEY MESSAGE 2...

A ridge of high pressure will keep conditions dry through Tuesday. The high pressure will then slide east late Tuesday as a shortwave trough moves in from the west. While there is some uncertainty on how quickly the rain associated with this feature moves in, guidance agree that the dry conditions come to an end by Wednesday morning. Showers will then continue throughout the day, and limited instability and shear may support some isolated thunderstorms. PWATs with this system will be 1.75 to 2 inches, so periods of heavy rain will be possible. There may be a brief period of rain-free conditions Wednesday night before the next disturbance brings another round of showers through on Thursday. PWATs will once again be near 2 inches. There is quite a bit of spread in guidance on how much instability there will be. The NAM is in its own zip code with 4000+ J/kg of MLCAPE. Compare that to the GFS that maxes out at 1500 J/kg. Shear will be relatively weak as well. With rain and clouds in the morning, the GFS is likely more representative of what the conditions could potentially be. While thunderstorms will be possible, confidence is low for the potential for stronger storms.

High pressure will briefly build into the region Thursday night into Friday and bring a lull in shower activity. A cold front approaches the region Friday morning and moves through late in the day and overnight. As previously mentioned in Key Message 1, there is uncertainty with the timing of this front. A later timing would favor more daytime heating and a greater potential for thunderstorms. It should be noted that WPC has the region outlooked for Excessive Rainfall for Friday. While there is potential for heavier rain with the prior systems, models are not showing much for total precipitation leading up to Friday. PWATs are also not as high with this frontal system. Given this, there is low confidence for any hydro issues at this time. The weekend has the potential to be mostly dry with the return of high pressure. A weaker frontal system will move through the region late in the weekend, though there is uncertainty with the coverage of showers.

AVIATION /18Z MONDAY THROUGH SATURDAY/

A pesky cloud deck remains across portions of NEPA and CNY today. Moisture from the Atlantic earlier this morning was pushed west, and now it is trapped under the axis of a surface ridge sitting over the area. Not a lot of steering currents are present over the area so the cloud deck is slowly drifting north with daytime heating now pushing ceilings back to VFR. These clouds are expected to slowly dissipate as the afternoon progresses and should clear out by the early evening hours.

Most of the region should be VFR tonight, but high pressure overhead and mostly clear skies should allow for valley fog to develop. ELM is interesting in that the clouds over the area right now were not modeled to be there and should keep the valley cooler this afternoon. The lower temperatures will allow overnight lows to reach the dewpoint much easier than if it was sunny and surface dewpoints dried out this afternoon. Guidance is showing signs of IFR and lower fog tonight but confidence is medium at this time as model soundings show low level winds remaining active, which would help mix out any fog that forms. Current thinking is there will be periods of fog that roll in and out of the terminal tonight. Guidance for the next set of TAFs should be better as the afternoon conditions will be ingested and should produce initial conditions closer to what is being observe. This should allow for a better handle of the fog development chances.

Outlook:

Tuesday afternoon and evening...VFR.

Tuesday night through Friday...Scattered showers and thunderstorms may bring occasional restrictions, especially each afternoon.

BGM WATCHES/WARNINGS/ADVISORIES

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