textproduct: Binghamton

WHAT HAS CHANGED

There remains fairly dry air in the low levels across the region, so limited PoPs during the day to only a slight chance of showers with increasing chances for rain overnight into Tuesday.

KEY MESSAGES

1) It will stay mainly dry and seasonably mild through this afternoon.

2) Unsettled weather returns tonight and persists through much of the week and possibly into this weekend. Thunderstorms and locally heavy rain will need to be monitored through the week, as this will bring the potential for flash flooding and possibly some minor river flooding.

DISCUSSION

KEY MESSAGE 1...

Today should remain mostly dry, with some morning sunshine followed by increasing afternoon clouds. Temperatures will be warm, with highs in the upper 50s to low 60s. A weak shortwave moves overhead later this afternoon and this could produce a few scattered showers or sprinkles. A frontal system will edge closer to the region tonight and more widespread rain showers will be possible overnight into Tuesday.

KEY MESSAGE 2...

An active weather pattern is expected over the next week. Deep southwesterly flow will bring Gulf of America moisture northward into the Northeast U.S. A near stationary or slow moving frontal system will start sagging southward out of Canada overnight Monday and Tuesday. This will bring the first period of light to moderate rain showers tonight.

For Tuesday, PWATs will continue to increase to 2+ standard deviations above normal for this time of year. Most of our area will be well into the warm sector south of the front on Tuesday. Model soundings show abundant moisture, are showing those PWATs in the 1.0 - 1.3 range). Mid level lapse rates are expected to increase over 7C/km by Tuesday afternoon and evening, however the lower levels will likely remain stable, so MUCAPE values only get to about 500 J/kg due to the stable low levels. SPC does have the western half of our area under a Marginal Risk; but this will be highly dependent on seeing any clearing and daytime heating, because otherwise there will not be enough instability. WPC Excessive Rainfall Outlook for Day 3 (Tues- Weds) suggests a Marginal risk of heavy rain generally along and north of the NY Southern Tier, where rainfall rates could exceed the very low flash flood guidance (anything more than 1-2 inches in a 6 hour period could start to cause issues).

The main concern will be long duration moderate to heavy rainfall rates as the stationary front slowly walks across the area Tuesday through Wednesday. Models show the front barely making it into southern PA or the northern Mid- Atlantic by Wednesday evening before it lifts back north a warm front on Thursday. This will bring another round of rain and showers to the area through Thursday night...with yet more rain potential on Friday as the center of the low and eventual cold front press through the area. The latest guidance continues to show the cold front stalling out as it approaches the Mid- Atlantic states due to a strong Bermuda High off the coast. This will open the door for a third system to bring more rain over the coming weekend. Behind this weekend system, a stronger front will should clear out the moisture for a while by the end of the weekend.

There are a lot of variables associated with each of these systems, however the simple fact that each system may stack more and more water across our increasingly sensitive watersheds lends careful watching.

AVIATION /12Z MONDAY THROUGH FRIDAY/

VFR conditions are expected at all terminal sites through at least 18z. A warm front is lifting in this afternoon, so cigs will likely be slowly falling all day, becoming MVFR around or after 00z. Some rain is possible but confidence is too low to add into this TAF package.

Outlook:

Monday late afternoon through Thursday...a chance of rain showers and associated occasional restrictions possible. Thunder possible each afternoon starting Tuesday afternoon.

Friday...Scattered rain showers and associated occasional restrictions possible.

BGM WATCHES/WARNINGS/ADVISORIES

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