textproduct: Binghamton

WHAT HAS CHANGED

Cloud cover was increased through late afternoon, along with PoPs increased for some light showers or drizzle around Central NY. The cool northwest flow and clouds will keep temperatures down into the 60s through mid afternoon, then perhaps topping out in the upper 60s to mid-70s for highs early this evening as the solid cloud cover finally scatters out. Widespread valley fog is expected tonight into early Tuesday morning as winds diminish and skies clear. Overnight lows were dropped into the upper 40s to mid 50s as high pressure moves overhead. Patchy fog was added Tuesday night into early Wednesday morning as well; some stratus clouds could also develop over NE PA and the Catskills.

KEY MESSAGES

1) Clouds giveway to more late day sunshine, with breezy northwest winds and cooler temperatures today. Clearing skies and diminishing winds will allow widespread valley fog to form tonight.

2) Dry and pleasant weather is expected Tuesday across the area, as high pressure settles overhead. Wednesday will be mainly dry and warm, but a few isolated showers or thunderstorms will be possible later in the day.

3) A trough of low pressure will increase moisture, humidity and instability over the region Thursday into Friday. This will lead to more widespread shower and thunderstorm activity. Scattered showers and storms linger into the weekend.

DISCUSSION

KEY MESSAGE 1...

Current visible satellite loop shows plenty of stratus clouds lingering across west-central NY and much of NE PA early this afternoon. The water vapor loop does show drier air working into the region in the mid levels of the atmosphere at this time. Radar shows lingering light showers, sprinkles or drizzle moving slowly east across most of Central NY. Based on these trends, increased cloud cover and PoPs through 3-5 PM, and lowered expected high temperatures. It looks like skies will finally become broken to scattered with some late day sun; again mainly after 3-5 PM. High temperatures should still be able to reach the upper 60s to mid-70s in most locations...with some upper 70s to low 80s still possible across the Wyoming Valley and perhaps the southern tier valleys.

NW winds around 10-15 mph with gusts 20-25 mph will gradually diminish by late afternoon and evening, dropping below 10 mph overnight as a surface high builds over the area. As skies clear and winds become light and variable, expect widespread valley fog to form, lingering into early/mid morning Tuesday. Overnight lows will be quite cool, in the upper 40s to mid-50s areawide.

KEY MESSAGE 2...

A much drier air mass settles over the area for Tuesday, with PWATS dropping to near 0.50 inches and dew points in the 50s for the afternoon. A 1020mb high will remain centered over the area through the day, along with upper level ridging as 500mb heights reach 590dm. After the morning fog burns off and dissipates, expect sunny skies, light winds and seasonably warm temperatures in the upper 70s to mid-80s. Some modest moisture return begins along the East Coast heading into Tuesday night. There could be some stratus clouds developing and moving in from the south overnight. Otherwise, expect some patchy valley fog development and seasonable lows in the mid 50s to low 60s.

Moisture begins to gradually increase through the day on Wednesday, as the southwest return flow develops on the west side of the Bermuda high. PWATs increase gradually up to around 1 inch again by late afternoon, and some modest instability could develop as dew points recover into the 60s. Expect some scattered cumulus development during the day, with a few isolated showers or thunderstorms also possible...mainly across NE PA and the Central Southern Tier of NY. Overall, much of the area looks to remain dry on Wednesday though. It will be warm once again, and a little more humid with highs in the low to mid-80s (except upper 80s for the Mohawk valley and Syracuse metro area).

KEY MESSAGE 3...

Deep moisture returns to the area Thursday and Friday, with PWATS likely hovering around 2 inches. With ample moisture and some daytime heating expected, this will create quite a bit of instability. 12z GFS is showing 1500-3500 J/kg of MUCAPE over the forecast area Thursday afternoon, with 1000-2000 J/kg of MLCAPE at the same time. Deep layer shear will be on the lower side, generally between 20-30 kts on the western periphery of the strengthening, offshore Bermuda high pressure ridge. There does not appear to be much of a lifting mechanism, as we are not expecting any strong frontal passages on Thursday. It seems minor disturbances and shortwaves could ripple through the area from the Ohio Valley and western PA. With PWATs progged to be 2 to 2.5 standard deviations above normal and surface based CAPE potentially 2000-3000 J/Kg even a small trigger could initiate clusters of showers and thunderstorms. The ensemble blend (NBM) has 12 hour PoPs of 75-85 percent on Thursday afternoon, and was inclined to keep this due to the above noted setup. Forecast soundings from the NAM and GFS show no cap in place Thursday afternoon, with long deep CAPE profiles and potentially high DCAPE values. As is typically the case it will depend on how much daytime heating occurs. Current model forecast push temperatures up into the low to mid-80s for highs.

The setup looks very similar for Friday, but if the 12z GFS is correct there would actually be more troughing pushing into the area from the west, which would provide more lift. Overall, the exact timing and placement of storms remains uncertain during this time period...but the setup does look favorable for possible heavy rainfall and gusty winds with some the storms. This will be something to monitor closely as we get closer in time and specifics become more clear. High temperatures remains steady in the low to mid 80s on Friday once again.

Moisture and instability remain in place for the upcoming weekend. The offshore Bermuda high weakens and retreats eastward. Overall, most model guidance keeps a fairly zonal flow over our area Saturday and Sunday. Without a strong front or lifting mechanism chances for showers or t'storms fade back to isolated or scattered. Temperatures remain steady with highs in the 80s and lows in the 60s.

AVIATION /18Z MONDAY THROUGH SATURDAY/

Northwest flow behind the departing cold front will continue to produce lingering showers/drizzle at SYR, RME, ITH and BGM this afternoon, along with ceiling and vsby restrictions through 20-22Z. Conditions are expected to eventually reach VFR after 00Z before fog develops tonight with MVFR to IFR at all terminals except SYR.

Northwest winds this afternoon will gust up to 25 kts. By the evening, winds become light and variable overnight and into Tuesday morning.

Outlook:

Tuesday afternoon and Tue night...Mainly VFR.

Wednesday through Saturday...Scattered showers and isolated thunder; associated restrictions possible.

BGM WATCHES/WARNINGS/ADVISORIES

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