textproduct: Binghamton

WHAT HAS CHANGED

Precipitation chances were slightly reduced across the area for this afternoon and evening.

KEY MESSAGES

1) Warm and humid conditions today, with isolated showers and thunderstorms possible later this afternoon into tonight across the area.

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 /18Z THURSDAY THROUGH TUESDAY/

Weak high pressure in place across the region this afternoon with currently a broad area of shallow cumulus. As the afternoon progresses the cloud layer should deepen and scattered showers and storms will develop. The most favorable area is still north of ITH, but have added VCTS to ITH, ELM, BGM and AVP for a couple hours to account for this uncertainty. Locations that see rain today/this evening will have a higher chance of seeing low clouds and fog later tonight. A weak wave will ride eastward through the southern tier of NY and be dissipating Friday morning between 13-18Z. A few rain showers are possible.

SW winds around 10 kt this afternoon will subside to variable and less than 4 kt tonight before veering to the NW Friday morning around 5 to 13 kt.

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.