textproduct: Binghamton

WHAT HAS CHANGED

Heat advisory issued for Tuesday for portions of the area. A extreme heat watch has been issued for Wednesday through Friday for the entire forecast area.

KEY MESSAGES

1) Heat and humidity will increase through this week leading to elevated heat index values.

2) Along with the heat and humidity, Tuesday through the end of the week could have daily isolated to scattered thunderstorms, some of which could be strong with a potential for localized torrential rainfall.

DISCUSSION

KEY MESSAGE 1...

No major changes to the significant details with this forecast update. Forecast is still showing a large heat dome building over the eastern U.S through the week. This will bring the warmest temperatures to the region so far this summer. Temperatures in the 90s and dewpoints from the upper 60s to mid-70s are exhibiting a high confidence of occurring. As such, a heat advisory has been issued for Tuesday for portions of the region and a extreme heat watch has been issued for the entire area for Wednesday through Friday. There remains some uncertainty on whether or not extreme heat criteria (HI 105 or greater) will be exceeded. The most likely areas of this occurring will be in urban valleys and the 105 HI threshold is not expected to be too widespread. There are several caveats that could prevent high temperatures from reaching their fullest advertised potential. Dew point temperatures could mix lower during afternoon period and the lower humidity would cause lower HIs and also, there remains potential for at least isolated afternoon convection each day this week.

Finally, unsettled conditions along a cold front dropping out of Canada this weekend will bring relief from the high heat and lower dew points a bit as well.

KEY MESSAGE 2...

Very tricky weather pattern over the coming days as we will be close to the periphery of the upper ridge. Depending on how strong and amplified the ridge becomes will determine our fate for thunderstorm chances this week. Chances of Thunderstorms have been kept in the forecast for the afternoon and evening for Tuesday and Wednesday. The is potential for a ridge runner MCS during this timeframe, and although chances may be highest during the afternoon and evening hours, there is potential that an MCS could push through our region at any time during the next 2 days. Forecast soundings show incredible instability for both Tuesday and Wednesday, with potential CAPE values of 4,000 to 5,000 J/kg. Also, midlevel lapse rate Tuesday evening and night could exceed 8C/km as an EML moves overhead. Even during the overnight hours, MUCAPE of 2,000+ J/kg will be possible. Due to the extreme instability for this region, the potential for a long lasting MCS or Derecho exists for somewhere in the Northeast U.S. in the coming days, but at this time, it is not possible to pin down timing or location, but this will be something to monitor.

As mentioned, triggers for storms are tough to pin down, as we will be near the NE edge of the ridge and several shortwaves will be riding around the perimeter of the ridge and this will be needed to break the cap of the EML plume overhead. So, barring remnants from upstream MCS complexes propagating southward into the low level moisture axis within the ridge, we should mainly see limited to isolated activity, as storms may only be able to fire without a trigger over higher terrain. Also, outflow from any storms that can pop through the cap could continue to support additional storms to fire.

Forecasters will be monitoring upstream thunderstorm complexes over the coming days and confidence will increase for severe weather if we start seeing a long live MCS pushing across southern Ontario, Canada...Stay tuned.

AVIATION /18Z MONDAY THROUGH SATURDAY/

VFR conditions expected through the 18z TAF period.

Outlook:

Tuesday through Saturday...Mostly VFR, but intermittent restrictions will be possible with isolated to scattered showers and thunderstorms each afternoon.

CLIMATE

Current High Temperature Records:

6/30: BGM - 92 (1964), SYR - 94 (1971), AVP - 97 (1964) 7/1: BGM - 90 (2018), SYR - 94 (2018), AVP - 95 (2018) 7/2: BGM - 92 (1966), SYR - 96 (1963), AVP - 98 (1966)

Forecasts for 7/1 and 7/2 are at or near the daily records.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Extreme Heat Watch from Wednesday morning through Friday evening for PAZ038>040-043-044-047-048-072. NY...Extreme Heat Watch from Wednesday morning through Friday evening for NYZ009-015>018-022>025-036-037-044>046- 055>057-062. Heat Advisory from noon to 8 PM EDT Tuesday for NYZ015>018- 022>025-036-037-044-045-055-056.