textproduct: Binghamton

WHAT HAS CHANGED

Rainfall amounts for today have once again slightly increased with areas of moderate rain expected to hang on longer than previously forecast.

KEY MESSAGES

1) Widespread rain across the region will continue into the overnight hours remnant moisture from Isaias moving up the East Coast. Dry and warm weather returns on Monday.

2) A low pressure system will bring numerous showers and a chance for thunderstorms Tuesday. A deep upper trough may move through the region to end the week, bringing rain and the possibility for the first snow showers of the season.

DISCUSSION

KEY MESSAGE 1

The extra-tropical low from the remnants of Isaias continues to bring rain showers across the Southern Tier into NEPA. These showers will lift north as the afternoon progresses, with rain expected across the area by late afternoon. Moderate rain has moved into the Wyoming Valley region and should slowly spread to the NNE. Along and east of I-81 from the Wyoming Valley into Otsego county has the best chances to see 1.0-1.5 inches of rain from this system. Weak mid-level frontogenesis is progged to develop over this area and keep periods of moderate rain going into the early overnight hours. The low will kick east of the area during the overnight hours, with some lingering lake enhanced rain showers possible into the early morning hours. Some areas could see some minor urban flooding this afternoon and evening, especially across poor drainage areas. Flash flooding is not expected given the low rainfall rates and dry antecedent conditions in place across the region. Temps today should top out in the 50s, while only falling in to the upper 40s to low 50s tonight.

Ridging builds into the area from the west on Monday, bringing WSW winds and dry, warmer weather to the region. Highs on Monday are expected to climb into the mid to upper 60s.

KEY MESSAGE 2

The next weather system looks to impact the area on Tuesday. A low pressure system is forecast to track eastward across the Great Lakes into Ontario as the day progresses. This system should bring rain showers to the area with a chance for thunderstorms, a few which could be strong to severe west of I-81. We are expected to be in the warm sector of this low, with highs in the 70s and dewpoints in the 60s. This would allow for some marginal instability, 500-1000 j/kg of CAPE, to develop Tuesday afternoon while 30-40kts of 0-6km bulk shear moves into the area. The uncertainty with thunderstorms developing remains high as the models continue to have differences in timing and location of the low. Also, clouds are expected during the morning hours that would limit instability, especially if they hang on longer than currently forecast. If we can get some clearing for a few hours, the atmosphere should have the necessary ingredients to get some isolated thunderstorms to develop.

Behind this system, high pressure is expected to control the weather pattern into Friday. Our next big looks to be a very strong trough diving into the area from Central Canada. This trough has been modeled somewhat consistently between most of the major global models so confidence is moderate that we will get precipitation on Friday into Saturday. The big question is will this trough be able to tap into cold Canadian air and bring the first taste of winter to the region this weekend. Current model runs show a blast of cold air getting pulled into the region with this trough, dropping high temps from the upper 50s to low 60s Friday to the low to mid 40s Saturday. Friday night lows in the low to mid 30s are progged to crash to the mid to upper 20s Saturday night. With this cold air, the first snowflakes of the season will be possible on Saturday. Accumulations are not expected but cold, elevated surfaces could see a light, patchy dusting by the late afternoon hours.

AVIATION /00Z MONDAY THROUGH FRIDAY/

The back edge of steadier rain will cross the area over the next couple of hours from southwest to northeast. Behind the steadier rain, scattered showers and/or drizzle/mist will continue through around Midnight, possibly later as low level moisture continues through much of the night. Overall flight conditions tonight will be variable through the night and from location to location with the remnants of Isaias moving through the region earlier and lingering low level moisture remaining into the morning on Monday. Current flight categories range from VFR at the northern terminals to LIFR conditions for ELM & BGM. CIGs upstream in PA are remaining low and are expected to remain in the IFR to LIFR levels, with the northern terminals expected to lower as well. Mist and/or fog is expected to continue through the night with MVFR to IFR VSBYs expected, a period of lower VSBY to LIFR will be possible at times, especially over the higher spots.

Monday, flight categories will improve through the day, early LIFR to IFR conditions will improve to MVFR through the morning and VFR flight conditions can be expected for most of the terminals by the late afternoon.

Outlook...

Monday night...A mixture of MVFR and VFR conditions with weak high pressure passing well to the south of the area. Some showers may be close to the western terminals by daybreak on Tuesday.

Tuesday through Tuesday night...Restrictions possible as another low pressure system approaches the region with showers and a slight chance of daytime thunder.

Wednesday through Thursday...High pressure building in should result in mostly VFR conditions with the exception of valley fog at ELM.

Friday...Low pressure system approaches the region with restrictions possible.

BGM WATCHES/WARNINGS/ADVISORIES

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