textproduct: Binghamton

WHAT HAS CHANGED

High temperatures were lowered slightly this afternoon from NBM with a faster arrival of a cold front from the north combined with the cloud cover in place today. While an isolated shower or thunderstorm remains possible this afternoon, mainly over NE PA, slight chance PoPs were added late tonight south of Lake Ontario, mainly around the lake plain and northern/western Finger Lakes as an upper trough axis moves in.

KEY MESSAGES

1) Remaining warm today with some sunshine filtered through clouds. A moisture-starved cold front pushing south this afternoon and evening will allow noticeably cooler air to funnel in from the north for Thursday.

2) Low pressure moving south toward New England late Friday and Friday night will drag a cold front across the area with a reinforcing shot of cooler air Saturday through early next week.

DISCUSSION

KEY MESSAGE 1...

A ridge of high pressure centered off the Southeast Coast early this morning has been pumping up moisture from the south, and combined with an increase in cloud cover, dew points have risen noticeably over the past several hours so it may feel a little sticky in some areas first thing walking out the door. The ridge will start to weaken and flatten today as an upper trough and moisture-starved cold front push down from the north. As the front dips south, there may be just enough instability (about 300 to 500 J/kg of CAPE) and modest shear on the order of 30 to 35 knots to spark an isolated shower or thunderstorm or two this afternoon and evening, mainly across NE PA. With winds shifting out of the west to northwest by about midday, temperatures across CNY are expected to be in the mid and upper 70s, while the Twin Tiers, NE PA and the southern Catskills still warm up into the upper 70s to mid 80s. It will be a noticeably cooler night tonight with lows in the upper 40s to the mid 50s. There can be a stray shower overnight as well, mainly downwind of Lake Ontario across the lake plain and around the northern/western Finger Lakes, as the upper level trough axis begins to move in.

As the upper trough continues to swing through Thursday and 850mb temperatures fall to about +4C to +6C, there can be an isolated instability shower that pops up, with the best chance for anything to form looking to be over the Catskills. High temperatures Thursday will be averaging 10 to nearly 15 degrees cooler than today ranging mainly from the mid 60s to the lower 70s. Some of the higher terrain across CNY may fail to get out of the lower 60s in the afternoon. Overnight lows Thursday night range from the mid 40s to around 50 degrees.

KEY MESSAGE 2...

After a slight recovery on Friday with high temperatures in the upper 60s to the mid 70s, the next potent upper low drops south late Friday into Friday night and passes by just to our east across New England. The surface front with this feature can bring a few spotty showers to the area later Friday afternoon into Friday night, but the bulk of the moisture looks to stay east. With the low off to our east Saturday, a strong northerly flow will inject a fresh bout of cool, Canadian air over the region along with a pop up shower or two. Highs Saturday are expected to be in the upper 50s to the mid 60s. The Wyoming and Delaware River Valleys in NE PA will fare a little better with temperatures around or into the low 70s. It is expected to be a breezy day as well with gusts of 20 to 25 mph common. Lows Saturday night will be in the 40s areawide, and as mentioned in the previous forecast discussion, some upper 30s can't be ruled out in the typical colder valley locations.

Sunday through Tuesday of next week we start to see some variations in the upper levels with regards to placement and strength of waves of energy and upper lows around the region. Deterministic and ensemble model guidance is in support of the cool north to northwest flow continuing with below average temperatures Sunday and Monday in the 60s and low 70s. Temperatures look to inch a little closer to normal on Tuesday. While there is no real good source of moisture over the area early next week, with low heights and the cool temperatures aloft, some isolated pop up showers can't be ruled out.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

VFR conditions are expected through the TAF period as high pressure sits overhead.

There's a low chance for a brief storm near AVP, but confidence was too low to include it in the 12z forecast. If a storm were to develop near AVP, it would likely be between 20-22z, and we will re-evaluate the potential for the 18z forecast package.

Outlook: Wednesday Night through Friday...Mainly VFR. Might see a passing shower/storm at AVP late Wed afternoon that could briefly drop conditions below VFR.

Friday Night and Saturday...Chance for scattered showers and associated restrictions.

Sunday...Mainly VFR; potential for afternoon showers that could cause restrictions.

BGM WATCHES/WARNINGS/ADVISORIES

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