NOAA/NWS Binghamton Flood Potential

Briefing #5

Issued 2:00 pm July 2nd, 2013

David J. Nicosia

Warning Coordination Meteorologist

National Weather Service

Binghamton, NY

This Briefing applies to the NWS Binghamton Service Area only

- This area includes but is not limited to cities such as Syracuse, Utica, Ithaca, Elmira, Binghamton and Oneonta in NY State.

- This area includes but is not limited to cities such as Towanda, Montrose, Scranton, Wilkes-Barre in PA.

Summary

Deep southerly flow of tropical moisture will continue until at

least Thursday.

Potential continues for localized MAJOR flash flooding daily

through at least Thursday with each round of showers and

thunderstorms that forms.

Scattered showers and thunderstorms with locally heavy rain

developing over central NY and northeast PA at present.

Watching a larger batch of showers and thunderstorms over the

southeast U.S. and Mid Atlantic that is heading north.

Some models bring it through our region tonight, others weaken

it.

If this area of rain hits us, it would make conditions worse.

Susquehanna, Chenango and Tioughnioga Rivers expecting minor

flooding.

Headwater river points, streams and poor drainage areas in all

river basins will remain vulnerable to rapid rises and flash

flooding with locally heavy rain.

Rest of larger rivers and lakes not expected to flood at this time.

Previous events: June 28-29, 2013

Previous events: July 1-2, 2013

North Main Street Sherburne, NY last night

Courtesy: Rick L. Crow

7 day observed rainfall

7 day percent of normal: Purple 300 to 600% of normal!!!

> 600% of normal!!!!

Deep Tropical Moisture Feed through at least Thursday

Blocking High Pressures

Deep Tropical Moisture Feed

H H

Remnants of Gulf System

1230 pm Radar

Scattered showers/thunderstorms developing

Next batch of heavy rain heading north

Model Radar as of 5 pm this evening

Model Radar as of 8 pm this evening

Model Radar as of 11 pm this evening

72 hr rainfall amounts used in river models

30% Chance of Moderate River Flooding in highlighted area below.

Minor flooding main branch of Susquehanna River in NY

Moderate flooding Chenango River Sherburne

Minor flooding upper Mohawk River

Flash Flood Rainfall Thresholds

• Twin-Tier region of NY/PA around 1 inch of rain needed in 3 hours to cause flash flooding (red).

• Rest of area between 1.25 and 2.5 inches needed in 3 hours for flash flooding to begin.

Rainfall Timing

- Showers and thunderstorms developing this afternoon and will continue this evening

- Another batch of heavy rain possible later this evening??

- Locally very heavy rain will fall and cause more localized flash flooding.

- Wednesday and Thursday likely will see the same pattern with an afternoon and evening peak in shower and thunderstorm activity and associated highest risk for flash flooding.

- Pattern could break down by Friday with a reduced threat for flash flooding.

River Crest Timing • Tributaries of Susquehanna river in NY crest today,

tonight and Wednesday morning. • Main Branch of Susquehanna River in NY crests

Wednesday night/early Thursday. • Susquehanna River in PA crests Thursday below

flood stage. • Rest of larger rivers and lakes should remain below

flood stage. • Any smaller river tributary, stream, or poor drainage

area will be susceptible to rapid rises and flash flooding until Thursday.

• Biggest threat continues to be localized MAJOR flash flooding.

Current River Stages and Forecasts

http://water.weather.gov/ahps2/index.php?wfo=BGM

For continuous updates:

– General Weather Info: http://weather.gov/bgm

– River Forecasts: http://water.weather.gov/ahps2/index.php?wfo=bgm

– Probability River Forecasts: http://www.erh.noaa.gov/mmefs/