textproduct: Binghamton

WHAT HAS CHANGED

Chances for any isolated showers look negligible this afternoon and Saturday, so PoPs were held below mentionable levels. The timing of the incoming rain and front has slowed slightly for Sunday, this also allowed for temperatures to be increased a few degrees on Sunday. Temperatures and humidity levels are trending a bit higher next week.

KEY MESSAGES

1) Drier weather returns to the area today and Saturday as weak ridging and high pressure move overhead.

2) The weather pattern turns more active and wetter heading into the Sunday and Monday time period.

3) Expect a warm and humid pattern to persist Tuesday through Friday next week, with chances for a few showers or thunderstorms most days.

DISCUSSION

KEY MESSAGE 1...

Starting off with valley fog and comfortable temperatures early this morning. High pressure will be in place today through Saturday keeping conditions generally dry. There is a very low (< 10%) chance for a late day shower or thunderstorm to pop up over the Catskills or Central NY where the slow departing trough will still hold some influence. Otherwise temperatures warm into the upper 70s to mid- 80s, with generally comfortable humidity levels. Similar conditions are expected Saturday with mostly dry conditions through the day. Some model guidance (CAMs) are hinting at a surface convergence zone which could initiate a stray pop up shower or storm in the early evening hours near the Catskills once again.

As an upper level ridge moves in on Saturday, southwesterly flow settles into the region. As a result, temperatures trend slightly warmer with highs in the 80s over the region. Dry conditions will be short lived as another frontal system approaches the region during the overnight hours increasing precipitation chances west of I-81 before daybreak early Sunday morning. It will be milder and more humid Saturday night, with lows in the 60s.

KEY MESSAGE 2...

By Sunday, the next deep trough, front and low pressure center will be moving into the area from the Ohio Valley. With southwesterly flow out ahead of it, abundant moisture gets advected into the region increasing PWATs between 1.8 to 2.0 inches. It appears a series of warm fronts will lift through the area on Sunday as the slow moving low lifts north in southern Ontario Sunday morning. Model guidance is trending a bit slower with the eastward progression of this system on Sunday, which could make for a slower arrival of steady rain and thunderstorms. With that said, it still looks like numerous to widespread showers and scattered thunderstorms arrive Sunday afternoon; especially along and west of the I-81 corridor. Most model guidance is keep instability and CAPE levels at a minimum across Central NY and Northeast PA on Sunday. However, if more daytime heating were to occur, it would be possible for more organized convection to form. Wind shear parameters are favorable, with 0-6 km bulk shear of 40 kts and even low level 0-1km shear up to 30 kts indicated on NAM/GFS forecast soundings Sunday afternoon.

It is too early for specific details on exactly how much instability will be present, as that will certainly depend on daytime surface heating. The main concern is the risk for excessive heavy rainfall as this system moves through. Model guidance does show some timing differences in when the system will exit. The 12z, 18z and latest 00z GFS keeps a piece of the upper level low rotating over the Ohio Valley region through Wednesday, while the ECMWF and Canadian show it moving east sometime Monday with an upper level ridge building in behind. The GFS solution would bring the potential for a south to north oriented heavy rain band to the area during the day on Monday; when it is also indicating PWATs between 2-2.25 inches near or over the area, along with dew points in the 70s. The moisture advection is enhanced further on the GFS solution by mid level convergence and strong low to mid level jet along the western periphery for an Atlantic upper level ridge. If this slower eastward progression trend continues, then Monday will certainly need to be watched for heavy rain potential as well.

KEY MESSAGE 3...

Beyond this, expect a warming trend for the middle of next week with chances for afternoon and evening thunderstorms also in the forecast each day. 1000-500mb thicknesses rise between 570-573dm and remain steady at this level through Friday. 850mb temperatures hover between +14 to +18C in this Tuesday through Friday timeframe. Model consensus from the NBM showers chances for pop up showers and storms due to robust instability levels, plenty of low level moisture (Tds 65 to 72F)...with the highest PoPs being on Thursday as a shortwave trough approaches from the Great Lakes region. Ensemble consensus is for high temperatures in the low to mid-80s Tuesday, mid to upper 80s Wednesday and Thursday, before a slight drop back into the low to mid-80s Friday. After dew points in the 60s Tuesday afternoon, it becomes more humid and dew points reach around 70s Wednesday and Thursday next week. If there ends up being a good deal of sunshine, heat indices may reach the lower 90s at times mid week.

AVIATION /06Z FRIDAY THROUGH TUESDAY/

After all the rain over the past few days, VLIFR valley fog is likely at ELM through the early morning hours. Elsewhere, there is uncertainty if fog will develop this morning, but ITH and BGM will have the best chances of seeing at least a few hour of IFR fog until just after sunrise. Regardless, VFR conditions are anticipated to return by mid morning at all sites after any fog burns off.

Outlook:

Saturday...Mainly VFR.

Late Saturday Night through Sunday night...Rain and restrictions likely, with a chance of thunderstorms, as a moist frontal system passes through the region.

Monday through Tuesday...Lingering chance of scattered showers and isolated thunder; associated restrictions. Mainly Monday.

BGM WATCHES/WARNINGS/ADVISORIES

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