Area Forecast Discussion

WHAT HAS CHANGED

Followed NBM for rainfall totals and no major changes to the previous forecast.

KEY MESSAGES

1) Above normal temperatures and dry weather is expected today.

2) A cold front will bring widespread beneficial rain showers Thursday, followed by additional chances for rain Fri into Saturday with the greatest probabilities south and east of the Capital District.

DISCUSSION

KEY MESSAGE 1... After a mild morning with lows in the upper 40s and mid 50s today, unusually warm weather for late fall is expected this afternoon. With the high pressure system having moved to our east off the Atlantic coast, the upper level ridge currently positioned over western. NY will begin to slide east with the ridge axis centered overhead our region by mid morning/early afternoon. Southerly flow continues to help advect a moist airmass into the region with PWAT's gradually rising to near 1" along with dewpoints increasing into the 50s by afternoon. However with broad subsidence occurring over the region, any lingering low stratus in the morning should clear up with daybreak allowing for a mostly clear day across the region. Current model guidance show 850 mb ensemble anomalies increasing to +2 to +3 STDEV above normal and 850 mb temperatures ranging from about 12 to 15 degrees C, which is unusually warm for this time of year. High temperatures are expected to reach into the lower to mid 70s in the valley regions and into the upper 60s in the higher terrain areas today, potentially becoming close to just a few degrees shy of today's daily high records (the best chance at KGFL and KPOU with daily high records of 73 and 74F respectively). Probabilistic guidance has a high chance (70 to 90%) for much of the region to reach or exceed 70F and a medium to high chance (50 to 80%) for reaching or exceeding 75F in parts of the Mohawk and Schoharie valley. Normal daily highs for this time of year across the region are typically in the low to mid 50s. Breezier conditions are also expected with gusts up to 10-15 kts in the afternoon and evening, particularly in the N/S oriented valleys and southerly facing slopes.

KEY MESSAGE 2... Thursday morning, a low pressure system tracks from the Great Lakes region into southeast Quebec as its associated cold front approaches from the west. Out ahead of the the cold front, a band of showers enters the region, initially in the west/southwest ADKs and western Mohawk Valley just before sunrise Thursday morning. Long range deterministic and ensemble guidance then show the showers overspreading the Capital Region and the rest of eastern NY by late morning before lessening in coverage into the afternoon/evening as it arrives into western New England. PWAT's rise above the 75th climatological normal to 1 to 1.5" Thursday, along with the NAEFS ensemble anomalies increasing to +3 to +4 STDEV, however the better upper level forcing still looks to be to the west of the Hudson River Valley. Expected highest rainfall amounts Thursday to be in the southwestern ADKs with the latest probabilistic NBM guidance showing a 50 to 60% chance of 0.75" or greater in this area, while areas along and south and east of I-90 generally receiving less than 0.50" (only 40 to 50% probability of 0.25" or greater). Most locations will receive about a tenth of an inch of rain, which will be the most widespread measurable rainfall in close to 20 days for the region and therefore expected to bring an end to the recent dry spell. Thursday's highs will still run above normal in the mid 60s to around 70F in the valleys and in the upper 50s to low/mid 60s in the higher terrain. There will also be more noticeable humidity compared to lately with dewpoints increasing into the 60s. Breezy conditions will continue with gusts 15-20 kts.

The low pressure system over the Great Lakes region closes off to our west Friday night. As the positively tilted trough begins to enter western NY Friday night into Saturday morning, additional rain showers are expected along it's frontal boundary. Latest model guidance has the closed low tracking overhead Saturday, however there is still some variability of the timing and track of this wave of low pressure and front. The latest medium and long range models have a heavier axis of rain showers in areas south and east of the Capital Region Friday and Friday night with rainfall totals up to 1" in these ares and lighter amounts in the Capital Region and areas north and west. 24-hr NBM probabilistic guidance has a 30 to 40% chance for 1" or greater and a 60 to 70% chance for 0.50" or greater in parts of Dutchess, Litchfield, and Berkshire counties. There is a 40% or less chance for 0.50" or greater elsewhere. Much of the greater totals look to be south and east of our region at this time. Due to the recent dry spell, the rain will be beneficial and hydro issues are not anticipated at this time. Lingering isolated showers are possible into Saturday. Temps trend near to slightly below normal for the close of the weekend. The cooler and unsettled weather looks to continue into early next week.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Flying conditions are currently VFR across the region. Some thin mid and high level clouds remain around the region with light to calm surface winds. These clouds will gradually decrease over the next few hours. If clearing occurs fast enough, a brief period of IFR fog may develop at KPSF right around daybreak. Elsewhere, a larger T/TD spread and the thin cloud cover should help prevent any radiational fog from developing through the rest of the overnight hours.

During the day on Wednesday, flying conditions will be VFR for all sites. Skies will be fairly clear for all sites through the day with light south winds around 5 kts. Southerly winds around 5 kts will continue into Wednesday night, with few-sct high level cirrus clouds moving across the region. Flying conditions look to be VFR for most of Wednesday night as increasing cloud cover and the light breeze ahead of the next system should help prevent much fog from forming.

Outlook...

Thursday Night: Moderate Operational Impact. Chance of RA. Friday: Moderate Operational Impact. Chance of RA. Friday Night: Moderate Operational Impact. Chance of RA. Saturday: Moderate Operational Impact. Chance of RA. Saturday Night: Moderate Operational Impact. Chance of RA. Sunday: Low Operational Impact. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Monday: Low Operational Impact. Breezy. Slight Chance of RA.

ALY WATCHES / WARNINGS / ADVISORIES

CT...None. NY...None. MA...None. VT...None.