textproduct: Binghamton

WHAT HAS CHANGED

No significant changes made to the forecast at this time.

KEY MESSAGES

1) Scattered showers and thunderstorms are possible today, mainly during the afternoon and evening. A few storms could produce strong winds and heavy rainfall, especially over the Twin Tiers and into the Wyoming Valley.

2) Comfortably warm conditions this weekend will give way to increasing heat and humidity through the middle of next week.

DISCUSSION

KEY MESSAGE 1...

A cool front will be slowly drifting south today leading to a gradual wind shift from westerly early this morning to more northwesterly as the day wears on and the boundary sinks south. This boundary is expected to reach the Twin Tiers by late afternoon/early evening. While the wind shift will help lead to temperatures not being quite as high as yesterday from the Twin Tiers northward as highs range from the upper 70s to mid 80s, it will still remain humid with dew points in the mid 60s to around 70 degrees. South of the boundary high temperatures are expected to reach the mid and upper 80s in the Wyoming and Delaware River Valleys in NE PA.

While there can be a few isolated showers early this morning near the frontal boundary around north-central NY, a weak shortwave embedded in the broad troughiness above is expected to move through during the midday and afternoon hours from west to east. This feature combined with the frontal boundary can spark isolated to scattered showers and thunderstorms this afternoon and evening with the Finger Lakes through the central Southern Tier, Northeast PA and southern Catskills likely having the best chance of seeing any convection. Model soundings show a fair amount of dry air in the mid-levels and mid-level lapse rates are pretty modest. However, guidance does show steep low level lapse rates along with about 1000 to 1500 J/kg of MLCAPE from around Steuben county east through the central Southern Tier and SE into the Wyoming Valley and Poconos. 0-6km bulk shear values do look like they have trended down slightly from the previous forecast averaging 25-30 knots. Putting this all together, there is the potential that a couple of storms can be on the stronger side, with an isolated severe storm possible with damaging wind gusts being the main concern. SPC does still maintain a Marginal Risk for severe storms over this area.

To go along with the isolated severe threat, locally heavy rainfall is possible with any storm which can result in isolated instances of ponding on roadways or possible flash flooding, mainly in urban/poor drainage areas across the Twin Tiers into the Wyoming Valley and Poconos. PWATs look to peak around 1.50 inches with MBE vectors as low as 10 to 15 knots showing the potential for slow moving or back building storms. This combined with the slow-moving boundary all add up to a Marginal Risk for flash flooding across the aforementioned area from WPC.

Moving into Saturday, an upper level shortwave trough will be dropping down from the north and this could spark and isolated shower or thunderstorm during the afternoon and evening, mainly from the Twin Tiers on south, but then much drier air will be filtering in in its wake, leading to very comfortable conditions for the rest of the weekend with dew points in the the 50s.

KEY MESSAGE 2...

Surface high pressure building in from the north late Saturday combined with the previously mentioned low dew points will lead to a pleasant weekend overall with high temperatures in the upper 70s to mid 80s, which puts us at or just slightly above average through Sunday with overnight lows in the 50s and low 60s.

A broad and very strong upper ridge of high pressure over the western and central U.S. is expected to expand eastward early next week, leading to rising heights aloft and winds shifting from the comfortable northerly flow from the weekend to a warmer westerly wind. High temperatures on Monday range from the low to mid 80s in most places with upper 80s in the warmer valley locations. Dew points remain in the upper 50s and low 60s, but they are expected to be on the rise Tuesday and Wednesday leading to more humid conditions along with the heat. Highs Tuesday and Wednesday look to be in the mid 80s to lower 90s and with the higher humidity, will have to be monitored in the long range for any possible heat headlines.

With the strong ridge axis centered off to our west and general troughiness over New England, it does place our area in a position where we do have to monitor the potential for any "ridge riders" that could result in a chance for showers and storms. However, guidance does not handle these situations well, so this is something that bears watching into early and midweek.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

The current MVFR/fuel alt thin deck will slowly lift to VFR this morning. Additional scattered showers and storms are possible at KELM, KITH, KBGM, and KAVP this afternoon. We've continued to include a PROB30 group at 18z for the chance of storms.

Outlook:

Friday night...Dissipating showers and thunderstorms early...then patchy valley fog late. Restrictions possible.

Saturday into Tuesday...VFR likely with high pressure building in, morning fog potential at ELM.

BGM WATCHES/WARNINGS/ADVISORIES

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