textproduct: Binghamton

WHAT HAS CHANGED

Adjusted thunderstorm timing for today, pushing arrival times back by a few hours. Also adjusted thunderstorm chances for Friday the cold front has been forecast to speed up, limiting storm chances north of the Southern Tier.

KEY MESSAGES

1) High heat and humidity continues today, lasting into Friday. The weekend will be cooler but temperatures will remain above normal.

2) Multiple systems will traverse the area, kicking off scattered thunderstorms across the region today and Friday. Some of these storms could be severe, with damaging winds and hail as the main threats. Saturday will remain dry but another cold front on Sunday will bring a return of showers and storms in the afternoon and evening.

3) A broad upper level trough will bring cooler, more normal temperatures to start next week with a few periods of light rain possible.

DISCUSSION

KEY MESSAGE 1...

Temperatures have climbed into the mid 80s for most, and are expected to reach the upper 80s to low 90s by mid afternoon. With dewpoints in the upper 60s to low 70s, heat indices will reach the 90s for most. Valley locations across the Southern Tier and Finger Lakes will see values climb above 95F, which prompted the issuance of a Heat Advisory for these areas until 8pm tonight.

Temps and dewpoints will remain high tonight, falling into the mid to upper 60s and mid 60s, respectively.

Friday will be warm once again, but a cold front is expected to move into the area in the late morning hours, which will limit heating potential across the Finger Lakes and Mohawk Valley. They may see a brief period of upper 80s before the cold front moves through and drops temps back into the low 80s. Areas along and south of the Southern Tier could see temps reach the mid 80s to low 90s during the afternoon hours ahead of the cold front. With dewpoints in the mid to upper 60s, heat indices will climb back into the 90s. Confidence is not high enough to issue a Heat Advisory for tomorrow afternoon for these areas as questions still remain with the timing and speed of the front moving through and if early rainfall limits heating potential.

Behind the front, drier and cooler air will move in with highs in the low to mid 80s on Saturday with dewpoints in the 50s. A ridge on Sunday will push temperatures back into the mid to upper 80s before another cold front pushes through during the afternoon hours.

KEY MESSAGE 2...

The aforementioned heat and humidity will be the fuel that drives thunderstorm development today and Friday.

A shortwave trough is currently moving across northern OH, kicking off showers and storms over WPA and WNY. A cap currently remains over our area, but is expected to erode by 3pm. As the shortwave kicks eastward, it will provide the broad lift that, combined with MLCAPE values between 1500-2000 j/kg, will kick off scattered cellular thunderstorms moving into the area by the mid afternoon hours. As the axis of the shortwave moves into the area, the storms should transition into multi cell or linear segments as they progress across the area late this afternoon and evening. The main threat with the storms is expected to be damaging winds and small hail. PWATs in the 1.75-2.0in range indicate heavy downpours with isolated flash flooding possible, especially across portions of the Finger Lakes and Mohawk Valley that saw heavy rain yesterday. Storms should hit the I-81 corridor between 7 and 8pm and exit to the east by 10pm.

Friday will see another round of thunderstorms as a cold front pushes into the area from the west. Guidance has sped up the arrival of this cold front, now expected to push into our western areas by the late morning hours. This will limit CAPE values north of the Southern Tier. Vertical wind shear looks to be lacking ahead of and along the front as well, with values only approaching 20kts or so. With the severe storm ingredients somewhat misaligned, severe storms north of the Southern Tier currently look to be isolated at this time. A few storms may be able to become severe if they can tap into a localized area that has higher CAPE values and moisture, allowing strong downbursts to occur when the updrafts cannot hold the rain any longer. The best chance for severe weather looks to be along and east of the I-81 corridor as CAPE values should be the highest here and mid-level winds are forecast to increase, allowing for better storm organization and stronger winds to develop. Main severe weather impacts expected are damaging winds and hail. Rain should move east of the area by the evening, bringing a cooler, dry night.

Dry weather remains through Saturday and into Sunday as a ridge moves overhead. A trough approaches Sunday afternoon with an associated cold front that should kick off scattered showers and storms across the area during the afternoon and evening hours. Some of these storms could be severe.

KEY MESSAGE 3...

Near normal temperatures will return to start next week as a broad trough sits over the northern portion of the country. This will bring a period of beautiful weather with highs in the 70s and dewpoints in the upper 40s to low 50s. Rain returns by mid week as the trough axis swings through the eastern US.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

Showers and storms continue to move through the region. While thunderstorms have moved through the Central NY terminals, the line has yet to go through AVP but will do so over the next couple of hours. Heavy rain and strong winds are to be expected when the storms move through. Behind the line, light rain is being observed at some of the Central NY terminals. Following the rain, there is potential for lower ceilings and fog overnight. Confidence is highest at ELM and RME, though fog will be possible at all terminals given the added moisture from the recent rainfall. The uncertainty is with the sky cover as if skies do not clear out, then fog may not develop or will be slower to develop. Lingering low ceilings will be possible after 12z though conditions should return to VFR prior to 18z. There is another line of showers and storms expected tomorrow afternoon, there is uncertainty with timing and coverage.

As mentioned, strong gusts should be expected at AVP when the line moves through. Otherwise, winds will become calm this evening and overnight. West to northwest winds will gradually pick up throughout the morning. Peak gusts of 15 to 20 kts are expected during the afternoon. Like today, winds could be strong within showers and storms that pass over terminals.

Outlook:

Friday Night...Mainly VFR; fog and restrictions late overnight.

Saturday...Mainly VFR

Sunday...Showers and thunderstorms with associated restrictions possible.

Sunday night through Monday...Mainly VFR; early morning fog and restrictions possible.

Tuesday...Low chance for afternoon showers and thunderstorms and associated restrictions.

BGM WATCHES/WARNINGS/ADVISORIES

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