textproduct: Binghamton

WHAT HAS CHANGED

No significant changes made to the forecast at this time.

KEY MESSAGES

1) Warm and humid tonight with isolated showers and thunderstorms, mainly through the evening.

2) Additional showers and thunderstorms are possible Friday afternoon and evening along a stalled frontal boundary with localized flash flooding possible over the Twin Tiers into the Wyoming Valley.

3) After seasonal temperatures this weekend, heat builds into the area through the middle of next week with possible storms.

DISCUSSION

KEY MESSAGE 1...

Warm and moderately humid conditions across the area this afternoon. Temperatures will top out in the mid 80s to low 90s with dewpoints in the low to mid 60s. It will feel slightly muggy out, but nothing like last week. Heat indices will only be a few degrees higher than actual temperatures so heat headlines were not needed for today.

Showers and storms are expected to develop across portions of the area later this afternoon and evening. Model soundings are showing a mid level warm nose, capping convection across the area this afternoon. This should last into the early evening hours before finally breaking and allowing some isolated storms to develop. A very positively tilted trough and associated surface boundary is spread across the Great Lakes into Ontario and will slowly slide into the area late this afternoon into the evening. MLCAPE values of 1000-1500j/kg are expected to be present across the northern Finger Lakes into Oneida county late this afternoon and evening along with 0-6km bulk shear increasing to around 30kts. These parameters combined with the mid-level cap breaking should allow for a few storms to develop over the northern Finger Lakes into Oneida county. The window for these storms to become severe looks to be small as the cap is forecast to break only a few hours before sunset. That being said, an isolated severe storm with strong to damaging winds cannot be ruled out over this area.

Storm activity is progged to weaken as the evening progresses, but a few isolated showers and storms cannot be ruled out across the area into the overnight hours with the late breaking cap and warm and humid air sticking around. The trough is slowly moving to the east, and with its positive tilt, steering winds are mostly west to east. This will allow the "cool" front moving in from Canada to very slowly slide south through the area through the overnight hours into Friday. A few showers could develop along the boundary as it slides south.

KEY MESSAGE 2...

With the frontal boundary slowly sliding south and synoptic winds continuing to be from the west, humidity is expected to remain high but temperatures will be in the upper 70s to mid 80s on Friday. By Friday afternoon, a shortwave bringing some mid- level flow enhancement is forecast to move into the area. This shortwave combined with the front draped somewhere across the Twin Tiers will kick off scattered afternoon showers and storms across portions of the Finger Lakes, Twin Tiers and into the Catskills and Poconos. CAPE values around 1500j/kg combined with 0-6km bulk shear increasing to 30-40kts with the shortwave will allow for isolated severe storms to be possible from Steuben county east into the central Southern Tier and SE into the Wyoming Valley and Poconos, with damaging winds as the main threat. A Marginal Risk for severe storms has been issued by the SPC over this area.

To go along with the isolated severe threat, heavy rainfall leading to isolated flash flooding will also be possible across the Twin Tiers into the Wyoming Valley and Poconos. PWATs of 1.5-2in, MBE vectors below 10kts showing slow moving or back building storms, warm cloud depths of 11-12k ft allowing for efficient rainfall generation and a slow moving boundary all add up to a Marginal Risk for flash flooding across the aforementioned area.

Showers and storms should dissipate in the evening as daytime heating ends and the trough axis finally moves through the area, switching synoptic flow to northerly and ushering in cooler, drier air to the region. Friday night lows and dewpoints will be in the upper 50s to low 60s.

Key Message 3...

High pressure will be in control over the area for the weekend, keeping flow northerly and conditions dry and seasonal.

A very strong ridge centered over the western US will be the main weather driver through at least the middle of next week.

The ridge positioning this weekend will push the eastern edge of a surface high into our area. This will keep flow out of the north through the weekend with pleasant seasonal conditions expected.

The ridge will strengthen and build into the north central US by Monday. This will shift winds to westerly through mid-week and push hot air into the region. Monday should be the most "pleasant" warm day as temperatures climb into the mid to upper 80s but dewpoints remain in the upper 50s. The humidity will return by Tuesday and through mid-week as dewpoints climb up into the mid 60s. We may also see some storms develop and ride the edge of the ridge into our region. Confidence in this occurring is low at this time, but the pattern that is setting up lends itself to mesoscale convective systems developing over the north central US and that energy riding the ridge into our area. This is very dependent on where the MCS develops and how the flow around the ridge is oriented. Lots of times these systems have to develop first before model guidance can catch on to it and give us an idea of where storms may go, but the setup is good enough to mention the chance of this occurring now.

Long range model guidance is hinting at the center of the ridge retrograding westward back over the western US. This would more than likely put a trough over eastern Canada that would influence our weather pattern with cooler temperatures but more precipitation chances.

AVIATION /01Z FRIDAY THROUGH TUESDAY/

Isolated showers and thunderstorms look to stay away from all terminals this evening at this time. A brief gust was noted at KITH but that thunderstorm is moving between KITH and KSYR. Still monitoring a few thunderstorm well west of KAVP possibly requiring a TEMPO later on if they don't weaken over the next hour or two.

Confidence is higher with a MVFR stratus deck forming over all CNY terminals by the overnight hours with the potential for a few spots getting down to fuel-alternate levels. Ceilings should lift slowly to VFR by early afternoon. Additional scattered showers and thunderstorms are possible at KELM,KITH,KBGM and KAVP Friday afternoon but coverage and timing is too uncertain for TAF mention at this time.

Outlook:

Friday night...Dissipating showers and thunderstorms early...then patchy valley fog late. Restrictions possible.

Saturday into Tuesday...VFR likely with high pressure building in, morning fog potential at ELM.

BGM WATCHES/WARNINGS/ADVISORIES

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