textproduct: Binghamton

WHAT HAS CHANGED

No major changes to the forecast package. Flood Watch remains in effect for affected counties until tomorrow evening.

KEY MESSAGES

1) A low pressure system will continue to bring multiple rounds of showers and storms through Wednesday. Locally heavier rain amounts are possible, which could lead to localized flash flooding.

2) Scattered showers will be possible Thursday through the end of the week as this system slowly exits the region. The weekend will start out dry though rain may return by Sunday.

DISCUSSION

KEY MESSAGE 1...

Multiple rounds of rain showers and storms are expected to continue slowly across the area through the rest of the day today. Going into the evening, a strong LLJ develops and will help advect more moisture from the Atlantic into the area, and in combination with a shortwave system moving into the Poconos/Catskills area this evening, additional heavy rainfall with rates of 1-2 inches per hour is possible.

This system will slowly pivot eastward, which becomes the main cause for the potential for flash flooding. PWATs aren't too high (around 1.0 to 1.5), but due to the slow progression and pivot of this system, there remains a risk for flash flooding mainly for areas east of I-81.

Forecasted rainfall totals will range from 1 to 3 inches across the region. As mentioned, the strong LLJ and terrain effect will likely lead to an area of higher rainfall amounts, where locally totals will push into the 3 to 5 inch range in the Catskills and Poconos.The Flood Watch continues for affected areas until tomorrow evening.

Some instability is available for some storm development, but chances for a storm to become severe is relatively low. With any storm, moderate to heavy rainfall is possible.

As this system begins to move east and slightly northward overnight, wrap-around moisture will continue into tomorrow, mainly for Central NY, highlighted over the Finger Lakes region.

KEY MESSAGE 2...

This system will drift up the coast into New England by Thursday, through wraparound moisture on the back side of the system will continue to support light showers over the region through the end of the work week. A ridge will begin to push in from the west with drier air beginning Friday afternoon, with rain showers coming to an end by the late afternoon/early evening hours.

Over the weekend, a trough takes shape over the Northeast once again as a low pressure system develops in the Southwest. The flow around this low will tap into the Gulf and Atlantic, potentially advecting moisture northward into the region. There is uncertainty though if surface high pressure keeps conditions dry through Sunday or if showers develop with the trough digging in. Chances for showers may be better early next week as a cold front drops in from the north.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

As expected, a lull in the wet weather is developing around the terminals this evening with isolated showers and spotty drizzle expected through about 12-14Z. A mix of mainly VFR/MVFR conditions is expected for much of this evening before ceilings are expected to lower to MVFR/Fuel-Alt and locally IFR restrictions. Guidance still suggests that areas of fog are possible late tonight and early tomorrow morning, especially around ELM and ITH, but confidence in fog remains low because of low confidence in there being enough clearing. Since the last forecast, guidance is not showing visby nearly as low, so this does lean toward that concern that there may not be enough clearing overnight. As a result, low stratus seems to be more likely later tonight into early tomorrow morning. Also of note, ceiling obs continue to be higher than projected, so stayed slightly above model guidance for most locations, but LIFR ceilings cannot be ruled out, especially at BGM and ELM.

Showers look to increase again between 15-18Z coming out of the north and rotating back into CNY through 00Z although there is uncertainty where the main corridor sets up.

Outlook:

Later Wednesday night into Thursday...Scattered showers and isolated thunderstorms with associated restrictions.

Friday and Saturday...Mainly VFR; low chance of a shower or thunderstorm.

Sunday...Shower and thunderstorm chances look to increase later in the day with the next approaching system.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Flood Watch through Wednesday evening for PAZ039-040-043-044- 047-048-072. NY...Flood Watch through Wednesday evening for NYZ045-046-056-057- 062.