textproduct: Binghamton

WHAT HAS CHANGED

Lowered temperatures again for Thursday and Friday due to uncertainty with afternoon thunderstorms that could cool temperatures during the peak heating hours of the day.

KEY MESSAGES

1) Temperatures are expected to uptick as the week progresses, with well above normal highs and lows expected through the end of the work week.

2) Multiple systems are expected to move across the region this through Friday, bringing rain and thunderstorm chances. Some of the thunderstorms could be severe Wednesday through Friday.

DISCUSSION

KEY MESSAGE 1...

Southwest flow will continue to increase temperatures and moisture across the region today. Temperatures will top out in the mid to upper 80s, but with the added humidity today, it will start to feel much stickier than the past few days. The best place to be today will be in the higher terrain east of I-81, where temperatures will remain in the low 80s.

A lot of uncertainty remains in the temperature forecast for Thursday and Friday. Temperatures should climb into the mid 80s to low 90s on Thursday and possibly increase to the upper 80s to mid 90s on Friday. The warmest temps are expected to be in the valleys of the Twin Tiers, but with dewpoints expected to be in the mid to upper 60s, heat indices could rise into the low to mid 90s on Thursday and mid to upper 90s on Friday. However, forecast soundings continue to show loads of instability, with CAPE exceeding of 3000 J/kg and now models are indicating potential for a weak perturbation on Thursday that would kick off scattered thunderstorms and throw a wrench in the high temperature forecast. On Friday, the kicker for storms is more pronounced, as a cold front is expected to move into the area by mid afternoon. If this timing is correct, then widespread thunderstorms would again have a large impact on temperatures. One other thing that has not been mentioned in previous forecast is lingering nocturnal convection Thursday morning. An EML plume will push into the region through the early morning hours on Thursday, and depending on the exact timing, thunderstorms and lingering clouds in the morning could hinder heating during the morning hours, and once the sun is out again, instability will quickly increase and more storms will be possible by mid to late afternoon.

Temperatures will fall back to near normal to slightly above normal for the weekend and into next week.

KEY MESSAGE 2...

With the ridge axis moving east of the area and flattening out, CNY and NEPA will return to an active weather pattern through the rest of the work week.

Today will see increased southwest return flow increasing low level moisture and instability. A low pressure system moving out of the Great Lakes to the northeast will be the main weather driver for the day. The associated trough axis will slide through the area during the afternoon hours. The lift provided by the trough will combine with afternoon CAPE values between 1500-2000 j/kg and low level lapse rates of 7-8C/km to kick off scattered thunderstorms in the afternoon, with some having the potential to be severe. Currently, a lack of shear is holding back the potential for more widespread severe storms, but with PWATs in the 1.75-2in range, rain driven downdrafts could cause damaging winds. Hail will also be possible, although the lack of updraft organization should keep hail sizes on the low end. Areas hit by slow moving storms or hit by multiple storms could see isolated flash flooding.

Tonight, our attention turns to the potential for more thunderstorms. Forecast soundings show an EML plume moving into the region after midnight and elevated CAPE values climb to over 2500 J/kg with mid level lapse rates above 7C/km. There is potential for an MCS to ride the periphery of the ridge and push into our region from the Great Lakes. Due to the amount of elevated instability overnight with the EML in place, we can't rule out the potential for nocturnal severe thunderstorms.

Lingering morning convection on Thursday should eventually push out of the area by mid morning. There should then be plenty of time for instability to build into the early to mid afternoon. Models are showing a weak short wave pushing into the area by mid afternoon. This should be enough to kick off thunderstorms once again, especially with the strong instability in place. The area is currently under a marginal risk for severe thunderstorms again on Thursday.

Finally, a cold front is expected to push through the area sometime Friday afternoon. Lift from the front combined with CAPE values approaching 2000 to 3000 J/kg and modest 0-6km shear, could potentially kick off more widespread severe thunderstorms for Friday. Timing of the front will be the main severe weather driver. Many models are indicating an afternoon passage, but given there is a sharp, narrow ridge propagating across the area ahead of the front, the timing could change based on interaction with the ridge. PWATs will also be high so heavy downpours and isolated flash flooding could be an issue, but less likely than the severe thunderstorm potential.

The weekend should be mostly dry and seasonable as we will sit between a ridge to the south and a trough to the north. Active weather returns Sunday afternoon thru most of next week as we will be under a large upper level trough that will throw multiple shortwaves through the area next week.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Mostly VFR expected through at least 10Z this morning at all terminals. After 10Z, a warm front lifts in with cigs falling to MVFR or MVFR Fuel Alt areawide. Rain showers and potential thunderstorms start to form close to 19z, potentially lasting until 23z or so. Southwesterly winds with gusts up to 15 knots expected this morning and through the afternoon.

Outlook:

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

Saturday into Sunday...Cold front moves through with VFR conditions likely, potential fog at ELM overnight.

BGM WATCHES/WARNINGS/ADVISORIES

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