textproduct: Binghamton

WHAT HAS CHANGED

Adjustments made to the coverage of showers and thunderstorms through the holiday weekend. Slight adjustments made to temperatures and dewpoints to line up better with observations.

KEY MESSAGES

1) Dangerous heat and humidity continues today. Friday will be slightly cooler but the Extreme Heat Warning will remain valid. A cool front will drop in from the north Saturday, bringing cooler temperatures and lower humidity but conditions will still be hot.

2) Several rounds of showers and thunderstorms for the holiday weekend. Some storms may be strong to severe on Friday.

DISCUSSION

KEY MESSAGE 1...

Another dangerously hot and humid afternoon across the region. Temperatures currently in the low 90s should rise another 4-5 degrees as the afternoon progresses, and with dewpoints in the low 70s, heat indices will climb into the 100-110 range this afternoon and early evening. Overnight temps will not see much relief, with lows only falling into the low to mid 70s.

Friday will be "cooler" as the ridge begins to slide to the WSW. Highs will be in the low to mid 90s but humidity, especially in the valleys, will remain and keep afternoon heat indices in the low to mid 100s. Overnight lows will remain warm, with upper 60s to low 70s expected.

A cool front is expected to move in from the north on Saturday as the ridge continues to flatten and slide to the WSW. Timing of this front is still somewhat uncertain, with guidance showing an early morning passage to early afternoon passage. Most guidance does show the front stalling out around the NY/PA border with mid to upper 80s to the north of the boundary and low to mid 90s to the south. The humidity will also get knocked down a bit as well, with dewpoints expected to be in the low to mid 60s to the north of the front and mid to upper 70s to the south. Luckily, it seems like the days of 70+ dewpoints have left the area.

Cooler temperatures are expected for the start of next week as a trough moves into the area, bringing more cloud coverage and rain showers.

KEY MESSAGE 2...

Once again we are situated on the NW quadrant of the strong ridge that has impacted our region the past few days. This "Ring of Fire" pattern makes thunderstorm forecasting difficult. There is ample CAPE available with the extremely hot and humid conditions, but there us a mid level cap of warm temperatures that keeps free convection from happening. These patterns usually require a disturbance to ride the edge of the ridge and provide the lift needed to break this cap and kick off showers and storms. These disturbances are usually leftover energy from Mesoscale Convective Complexes that form in the Midwest and ride the ridge into our area. If guidance does not properly initialize the location and timing of these systems, forecasting the timing of storms in our area is very difficult, which has been the case for the past couple of days.

Today, we have ample CAPE in place but there is not a strong disturbance expected to move through the area and we are missing out on stronger 0-6km bulk shear(only around 20kts) needed to organize the storms that form. But because the instability is so great, an isolated severe storm cannot be ruled out north of the Southern Tier. Model soundings are showing very strong inverted V profiles and Downdraft CAPE in the 1000-1500j/kg range. These numbers show that a strong updraft that collapses would be able to produce a localize microburst. The best chance for this currently looks to be in the late afternoon to evening hours.

Friday will see better chances for more widespread severe storms during the afternoon and evening hours. Very high instability will once again be present, with 0-6km bulk shear increasing to 30-40kts. The energy from a MCS currently over IA/MN is expected to track into the region Friday afternoon, helping break any mid-level cap that might be present. SPC has placed out area in a Slight Risk for severe storms, and the current parameters in the forecast match up with this outlook well.

The 4th of July is unfortunately forecast to have thunderstorms, but the timing and location of the front will help drive where the storms form. A couple of disturbances are forecast to move through the area, but these will be highly dependent on the track and speed they are on as they exit the upper Midwest and move into the Great Lakes and Canada. The past couple of model runs have been widely varying so confidence in where precipitation occurs on Saturday is low at this time. Cuyrrently, the best chance for severe storms is across the Wyoming Valley, stretching through the Poconos and into the southern Catskills.

The pattern will change to start the work week, with the strong ridge retrograding to the west and a trough moving into the Great Lakes region. This will bring us a chance for rain showers and storms into midweek.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

VFR conditions are expected for all terminals through the 18z TAF period.

Isolated showers and storms are possible this afternoon and evening. The coverage is expected to be much lower compared to yesterday, with more capping in place. RME and SYR may have the best chance of seeing any pop up convection, but confidence is too on timing low to include in the TAFs at this time. It remains VFR heading into the overnight hours. We will AMD with TEMPOs for any incoming storms.

Outlook:

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

Sunday Night through Monday...Restrictions possible due to widespread showers and afternoon isolated thunderstorms.

CLIMATE

Current High Temperature Records:

7/2: BGM - 92 (1966), SYR - 96 (1963), AVP - 98 (1966)

Forecasts for 7/2 are at or just over the daily records.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Extreme Heat Warning until 8 PM EDT Friday for PAZ038>040-043- 044-047-048-072. NY...Extreme Heat Warning until 8 PM EDT Friday for NYZ009-015>018- 022>025-036-037-044>046-055>057-062.