textproduct: Binghamton

WHAT HAS CHANGED

Updated winds tonight into tomorrow to increase them across the western Finger Lakes. Wind directions aloft are favorable for some downsloping, mixing some higher gusts to the surface.

KEY MESSAGES

1) Back to back low pressure systems bring rain chances to the region tomorrow through Thursday morning, and windy conditions tonight into tomorrow.

2) A cool air mass settles into place late this week through the weekend leading to below average temperatures and chances of frost and freezes during the overnight hours.

DISCUSSION

KEY MESSAGE 1...

High pressure in place today has lead to a beautiful afternoon with light winds, low dew points, and sunny skies. High clouds are starting to move in from the west, with sky cover expected to increase overnight, helping keep overnight lows warmer than this morning. The Catskills into Sullivan and Pike county may still see some patchy frost as the clouds dont move in till late with plenty of time for radiational cooling. 850-mb winds increase out of the south as a low level jet forms in the overnight hours ahead of the approaching front. The western Finger Lakes region could see some enhanced winds late tonight and tomorrow morning thanks to downsloping that may help mix down some of the higher winds aloft, with gusts over 40 mph possible. Elsewhere will still see gusty winds but likely stay in the 20 to 30 mph range.

Tomorrow, dry air will make it tough for rain showers to be heavy so while chances of precipitation is high, especially west of I-81, rainfall amounts are light. Most of the rain will evaporate before reaching the ground, especially along and east of I-81. This first area of low pressure helps saturate the atmosphere ahead of our next low pressure system Wednesday into Thursday. This low originates in the Southern Plains and picks up some gulf moisture as it tracks into the Northeast. Precipitable water values get up to around an inch, with the low moving through fairly fast Wednesday night into Thursday, which will limit the duration of the heavier rain. Still, an inch or so of rain is forecast overnight Wednesday and with greenup still progressing and soil moisture is still high from the weekend rain, river rises are expected. Right now, rainfall is not expected to be heavy enough to get flash flood concerns and with the short duration, rivers are forecast to remain below flood stages.

KEY MESSAGE 2...

Behind the low pressure systems Thursday into the weekend, a long wave trough sets up over the northeast with cold northerly and northwesterly flow. 850 mb temperatures look to remain below freezing but does not really get below -5C to support snow. Day time highs will still likely get into the upper 40s and low 50s with the strong solar heating at this time of the year. This heating may also lead to some afternoon instability so isolated to scattered afternoon rain showers are likely Friday into early next week. Overnight lows will need to be watched with the growing season starting for NEPA and the Finger Lakes region May 1st. One thing that may help keep overnight lows a little warmer is the amount of low level moisture in place and any afternoon rain showers could help boost the surface dew points. This would lead to more fog formation and may keep lows just above freezing. If high pressure ends up building in any night between Thursday night into early next week, there is a high chance of a frost or a freeze.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

VFR conditions are expected at all terminals through the TAF period.

Tricky low level wind shear (LLWS) forecast and at this time it does appear most areas will mix enough overnight as winds increase aloft. SYR will have the best chance for LLWS conditions as a low level inversion will be in place there a few hours before sunrise, but all other sites will likely have low level turbulence not shear due to the boundary layer being too well mixed tomorrow morning and winds will likely be gusting at the surface.

Outlook:

Monday night...Mainly VFR expected; low-level wind shear and fog possible early Monday morning.

Tuesday...Rain showers moving in from west to east with associated restrictions, mainly in the late afternoon and at night.

Wednesday through Friday...Additional scattered showers and associated restrictions possible.

BGM WATCHES/WARNINGS/ADVISORIES

PA...None. NY...Wind Advisory from 11 PM this evening to 11 AM EDT Tuesday for NYZ015-022.