textproduct: Binghamton

WHAT HAS CHANGED

No significant changes with this forecast update. The forecast remains on track, and flood watches were left in place. PoPs and rainfall amounts were adjusted based on the latest radar trends and model data. Higher confidence in Wednesday being dry now.

KEY MESSAGES

1) Showers and embedded pop up thunderstorms will continue to develop over the region today in a very moist and somewhat unstable air mass. Flood watches remain in effect for most of the NY southern tier, Catskills and all of NE PA.

2) Low amplitude weak upper level trough remains in place Tuesday before exiting the region on Wednesday. This will bring partly sunny conditions, with chances for a few pop up showers or t'storms Tuesday, then dry and seasonable weather on Wednesday.

3) The next trough and front is progged to slowly move through the area Thursday into Friday. This will bring increasing chances of showers and thunderstorms along with more warm and humid conditions.

DISCUSSION

KEY MESSAGE 1...

A stalled stationary frontal boundary is the focal point for developing showers and thunderstorms across NE PA and the NY southern tier early this morning. Radar estimates and rain gauge reports show that localized amounts have been 2-5 inches across portions of Luzerne, Lackawanna, Pike and Sullivan (NY) counties. Numerous flash flood warnings were issued and some remain in place. Please check official NWS sources for the latest warning information.

The latest CAMs, such as the 04z HRRR show showers and embedded t'storm pivoting and rotating over areas south and east of Binghamton through sunrise, before finally shifting slowing east into southern New England. Still additional pop up, slow moving heavy showers or perhaps t'storms are progged to occasionally develop along the NY/PA into the mid-morning hours. However, it appears most areas will indeed see a break in the steady/heavy rainfall from about 6 AM to Noon. Then, heading into the afternoon hours some modest daytime heating and instability will allow additional showers and storms to develop with an incoming shortwave. Storm motion vectors still show very slow movement, with showers and t'storms likely to drift at less than 10 mph this afternoon. PWATS remain very high, between 1.8 to 2 inches over NE PA and the southern tier region. Warm cloud layer depths are also progged to be around 11-12k ft agl. So these parameters are still supportive of very efficient warm rain processes. Additional rainfall amounts are forecast to be between a half inch to 1.5 inches in and around the flood watch zones through early Tuesday morning; with perhaps still a few very localized higher totals where showers/storms stall.

The positive note is that overall instability levels looks much lower than what we had in place Sunday evening; with MLCAPE values less than 200 J/kg expected due to a cooler maritime air mass advecting in on the east wind (creating CIN). Will leave the flood watches in place at this time, but overall the flood threat for this afternoon and evening is trending down in the latest model guidance.

KEY MESSAGE 2...

The upper level trough never really leaves the area entirely heading into Tuesday and this setup will keep at least a chance for at least isolated to scattered showers and t'storms in the forecast, along with mostly cloudy skies. With all the clouds and scattered showers around, it stays on the cooler side as highs only reach into the 70s once again. There could be a few more breaks of afternoon sun up toward the I-90 corridor, Mohawk Valley and Syracuse metro area; this allows for highs near 80 here.

By Wednesday, the latest ensemble forecast guidance continues to show dry conditions as weak high pressure builds overhead. Skies are also expected to become partly to mostly sunny and high temperatures warm up into the 80s areawide with moderate humidity levels forecast.

KEY MESSAGE 3...

Thursday is forecast to be the warmest day of the upcoming week and dry for the first half of the day. The area will be under a zonal flow pattern, however there is potential that a cold front pushes into western NY late in the day, bringing the chance for a few showers and thunderstorms. Depending on the exact timing, this front could bring strong to severe thunderstorms if it comes in during the peak heating hours of the afternoon, but some ensemble guidance has this front not passing until early Friday morning. Highs on Thursday reach well into the 80s with a few valley locations in the low 90s. With dew points in the mid to upper 60s there will be plenty of atmospheric instability around.

Most of the guidance is starting to agree on the main frontal passage being sometime on Friday. This will likely bring another round of showers and thunderstorms. Exact timing of the rain and convection remains uncertain this far out in time. There should be at least some dry time and breaks of sun, as guidance is showing temperatures in the low to mid-80s. Looking ahead to the weekend; overall it is shaping up to be mainly dry and seasonable. NBM ensemble guidance shows the possibility for a few showers or lingering t'storms Saturday, then generally dry on Sunday. Highs in the upper 70s to mid-80s each day with lows in the mid-50s to low 60s.

AVIATION /06Z MONDAY THROUGH FRIDAY/

RME and SYR are expected to remain VFR through the overnight and early morning hours on Monday. MVFR CIGs then potentially reach these two TAF sites by mid to late morning, with some scattered showers around...especially at SYR. CIGs are then forecast to come back up to lower end VFR by the mid to late afternoon hours.

Tonight, steadier and heavier rain will move in, mainly affecting the NY Southern Tier and NE PA. Cigs will get to IFR at BGM, but lower confidence at AVP and ELM. There is a chance of persistent IFR vis in a narrow band of heavier rain though exactly where that sets up is unknown right now. BGM and AVP have the highest chances of seeing this band set up over or near the terminal so added IFR tempos at these two sites. AVP has the potential to see a heavy thunderstorm this evening, mainly from about 02-06z. IFR CIGs then linger at BGM through the morning hours, with again lower confidence at AVP (so held it at MVFR fuel alt CIGs here).

Monday will feature generally MVFR to MVFR fuel alt CIGs for ITH, ELM, BGM and AVP with on and off showers expected; the rain could occasionally heavy at times with reduced visibility.

Outlook:

Monday night...Restrictions continue due to rain and fog/mist in the area. IFR likely at BGM and possible at ITH, ELM and AVP. SYR and RME mainly VFR until very late at night.

Tuesday...Lingering rain showers in the morning with MVFR conditions, trending towards VFR.

Wednesday through Friday...Mainly VFR; High pressure building in, morning fog likely, mainly at ELM.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Flood Watch through Tuesday morning for PAZ038>040-043-044-047- 048-072. NY...Flood Watch through Tuesday morning for NYZ024-055>057-062.