NOAA/NWS Binghamton, NY

Rain and Flood Potential Update

Briefing #2 May 15th, 2014 5:00 AM

Mark Pellerito, Meteorologist

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

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

This Briefing applies to the NWS Binghamton Service Area only:

Summary • Flash Flood Watch now in effect for This Evening

through Friday Evening for the following counties in NY: Steuben/Yates/Seneca/Southern Cayuga.

• Quiet today, but a widespread rain is expected Tonight through Friday evening; then ending early Saturday.

• During this time 1.5” to 2” of rain is expected, with isolated amounts of up to 3” possible.

• Flash flooding is the biggest threat, especially for areas that already received heavy rainfall the last couple of days (Flash Flood Watch counties). While creeks and small streams will be vulnerable, the threat of main stem river flooding appears minimal.

• Current Watches are where there is the most potential for flash flooding, but Watch Area could be expanded if confidence for higher rainfall amounts increases.

Watches/Warnings/Advisories as of 5 AM EDT Thu May 15

Flash Flood Watch this Evening through Friday evening (begins earlier in western portions of NY/PA). This is where

potential for flash flooding is higher; farther east could potentially have some issues as well, so monitor forecasts.

Rainfall Forecast (mostly tonight through Friday Night)

Widespread 1.5 to 2 inches, with localized amounts up to 3 inches possible.

Flood Impacts and Probability Scenarios

• Widespread 1.5” to 2” of rain expect: – The Most Likely Scenario

– Minor ponding/water problems in typical flood prone areas.

• Basements, low water crossings, storm drains.

– Flash flooding most likely threat, especially in areas that have already seen heavy rain or areas that see repeating rains (training).

– Major rivers rise but most points stay BELOW flood stage. A few headwater points may approach minor flood stage.

• If widespread 2” to 3” of rain, then expect: – ½ to ¾ bank full on the larger rivers.

– Smaller rivers (“headwaters”) could see minor flooding.

– Flash flood potential increases if this amount of heavy rain falls in less than 6 hours.

– 20-30% chance of this occurring.

• Widespread 3” of rain or more is when significant stream and river flood issues would begin. – Minor river flooding at most points. A few points would approach

moderate flood stage.

– Probability of this is very small…10% or less.

What to expect next?

• We will have another briefing update with latest information by around 3 PM Today.

Monitor Conditions!

• Continuous updates: http:weather.gov/bgm

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