FXUS61 KALY 281056 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 656 AM EDT Thu Mar 28 2024 .SYNOPSIS... Periods of rain showers track into areas mainly near and east of the Hudson River today with the most widespread and steady rain in western New England. Rain diminishes tonight with dry yet breezy conditions expected Friday and Saturday. && .NEAR TERM /THROUGH TONIGHT/... As of 6:45am, rain that overspread ares mainly east of the Hudson River into western New England overnight has diminished as we enter in the expected morning lull. MRMS rainfall estimates compared to NYS mesonet observations show estimates are slightly overdone but not by much. A general 0.25 - 0.50" of rain fell in Litchfield and Berkshire as well as southern VT before sunrise this morning with amounts quickly dropping off heading west into eastern NY. No rain fell observed so far at Albany Airport. We still anticipate rain to increase in spatial coverage by late morning, mainly along and especially east of the Hudson River, with periods of rain for western New England this afternoon. Little if any rain expected west of Albany. Otherwise, foggy conditions across the Upper Hudson Valley into southern VT continue as seen via the GFL METAR and area web cameras. Our SPS is set to expire at 12 UTC but the incoming day shift may choose to extend it based on expected trends. Previous discussion...Latest GOES16 water vapor and IR imagery shows a plume of moisture streaming northward from the Southeast into the Northeast. With a 300hPa jet intensifying over southern Ontario and much of the Northeast positioned in its right entrance region, increased upper level divergence and synoptic lift focused along the moisture corridor has allowed rain showers to blossom and spread into eastern NY and western New England but have remained mainly east of the Hudson River. MRMS and NYS mesonet observations should the steadiest rain in western New England with 3-hrly rainfall amounts ranging 0.10 - 0.25" in the mid-Hudson Valley, southern/central Taconics into the Litchfield and Berkshire County. As expected, there is a sharp east-west QPF gradient straddling the Capital District likely coinciding with the wind shift boundary with the City of Albany and Troy on the far western fringe of the rainfall while Schenectady and Saratoga remain dry. Areas along and east of this wind shift boundary have remained foggy as well through early this morning given the mild/moist air mass over the still cold ground (especially where a deeper snow pack remains). Our Special Weather Statement alerting motorist to reduced visibility mainly near and north of I-90 will remain in place through 12 UTC. Periods of rain continue through about 12 UTC or so before turning more scattered this morning for a few hours. However, this brief lull will be short-lived as rain becomes steady again by midday and continues into the afternoon. This is due to a southern stream shortwave in the Southeast that will round the base of the parent trough and take on a negative tilt resulting in increased height falls for much of the East Coast as a plume of rich moisture continues to stream northward. The steadiest and most widespread rain will likely be directed east of the Hudson River with western New England experiencing nearly a washout of a day. Probabilistic and ensemble guidance suggests that the east to west QPF gradient will be sharp and likely focused along an incoming mid- level boundary where strong low- level convergence will overlap the region of highest low and mid-level moisture. This corridor was used to decide the western extent of likely POPs which again only extended as far west as the Hudson River. POPs quickly trend downwards to chance for much of the Capital District and eastern Catskills with slight chance into the eastern Mohawk Valley and northern Catskills. The western Adirondacks and western Mohawk Valley likely remain dry today. Total QPF amounts today should range 0.25 - 0.50" for western New England, the mid-Hudson Valley, and the Taconics but quickly trend downwards to just around a 0.10" for the Capital District and Upper Hudson Valley. Given extensive clouds and incoming rain showers, temperatures today will be similar to yesterday, only rising into the mid to upper 40s. As our sfc wind shift boundary pushes east into New England this morning, west-northwest in its wake will strengthen becoming sustained 5-12kts. This will help scour our morning fog. Rain exits from west to east this 00 - 06 UTC tonight as a coastal low rapidly develops off the Carolinas and tracks northeastward towards New England. While previous forecasts discussed if the western fringe of this coastal low would scrape our western New England areas, latest guidance suggests the bulk of the rain will remain focused to our east thanks to the sfc wind shift boundary exiting to our east earlier in the day. Rain will linger over western New England the latest but should still exit by or shortly after Midnight. While the highest rainfall amounts for our hydrologic service area fall over the Housatonic River Basin which is already elevated given recent heavy rain events, latest forecast from the River Forecast Center still keep crest levels below flood stage. Although clouds will be slow to erode away tonight even after rain ends, breezy northwest winds with reaching gusts up to 25kts will result in cold and dry air advection. Overnight lows will drop into the low to mid 30s with mid to upper 20s in the higher terrain areas. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... Both Friday and Saturday will feature gusty northwest winds as our coastal low rapidly deepens off the New England coast and tracks into the Canadian Maritime. The tightening sfc pressure gradient overhead combined with cold and dry air advection will support deep boundary mixing both days, raising questions if guidance is adequately representing just how gusty we may become. We collaborated with neighboring WFOs to blend in more of the NBM90th and our latest forecast now shows northwest winds reaching up to 30-35kts on Friday and 25-30kts on Saturday. The strongest wind gusts should be focused down the Mohawk Valley into the Capital District and Berkshire County. Otherwise, Friday will feature limited sunshine as the parent trough moves overhead and cold air advection supports lake effect clouds extending off Lake Ontario into eastern New York and western New England. It will also feel cooler given drier air mass and gusty winds, despite highs reaching into to the mid to upper 40s to around 50 in the Hudson Valley. Gusty winds continue Friday night with skies gradually clearing towards sunrise as subsidence in the wake of the parent trough spreads into the region. Overnight lows again drop into the mid to upper 20s with around freezing in the Hudson Valley. Breezy winds keep temperatures a bit elevated. We finally will see the sun again on Saturday as large scale subsidence keeps skies mainly sunny, at least for the first half of the day. Deep boundary layer mixing and dry air advection (PWATs dropping under 0.25") will maintain the gusty northwest but winds should not be quite as gusty as Friday. Given deep mixing and the incoming dry air mass, we lowered dew points to match NBM10th guidance. We may check in with Fire Weather partners to check on fuel levels for Saturday as the dry air mass and breezy winds may raise some fire weather concerns. Otherwise, high temperatures Saturday should reach into the low to mid-50s for the Hudson Valley with mid to upper 40s for the hill towns and higher terrain. Some clouds return late in the day as mid-level ridging slides into New England and a warm front from the mid-Atlantic inches northward. Depending on the northern extent of the front, a few showers may graze our far western zones Saturday night but there is still a decent amount of spread in the guidance so limited POPs to just slight chance. Otherwise, temperatures should once again drop into the upper 20s to low-mid 30s for much of the forecast area. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... For the start of the extended period, dry weather looks to be in place on Easter Sunday. Fairly zonal flow will be in place aloft and our area will be in between any potential storm systems, allowing for a mix of sun and clouds with seasonable temps. With high pressure nosing southward from southern Canada, dry weather looks to also continue for Sunday night into Monday with temps near normal (30s at night and 40s/50s during the day). The next storm system looks to impact the region for the middle of the week. This will be large storm system approaching from the Great Lakes/Ohio Valley. As it heads toward the Northeast, the large upper level low associated with this storm system may cut off over the region. Steady precip looks to arrive on Tuesday and continue into Wednesday. Some high terrain and northern areas could see some snow or mixed precip at the onset, although most areas will see primarily rain with this storm system. However, some ensembles do suggest a changeover to snow showers before ending, as the large cold pool moves across the region by late Wed or Thursday. With a good chance for precip, have gone with high CHC or likely POPs for the midweek, along with plenty of cloud cover. Daytime temps will be held into the 40s with the expected clouds/precip and some 30s are possible for the high terrain. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... Widespread low level moisture continues to allow for plenty of low clouds and fog this morning. Although it had been solidly IFR/LIFR at all sites for most of the night, some improvement is starting to occur at KALB and KPOU, with ceilings now starting to rise back to MVFR. Over the next few hours, there will be a slow improvement at KGFL as well, with MVFR cigs by the mid morning hours. Meanwhile, flying conditions will remain poor at KPSF, with some additional periods of rainfall into the morning hours, keeping it IFR. With the stalled frontal boundary nearby, there could be some passing showers in the mid to late morning for KALB/KGFL, but it should be dry most of the time for these sites and visibility should improve for these sites as well, as a light north to northwest wind around 5 kts should help keep widespread fog from forming. Meanwhile, KPOU/KPSF will see light rain from mid morning onward through the day on today, as a slow moving frontal boundary continues to push west to east across the area. This should keep flying conditions generally IFR (mainly for ceilings) through the day, although there could be some improvement back to MVFR by late in the day. Light northerly winds are expected for these sites as well. For tonight, the boundary will be shifting eastward and rain will be ending. All sites should see MVFR ceilings around 2-3 kft. There should be enough of a north to northwest breeze in place to keep fog/mist from forming. Outlook... Friday Night: Moderate Operational Impact. Windy With Gusts To 30 kts. NO SIG WX. Saturday: Low Operational Impact. Breezy. NO SIG WX. Saturday Night: Low Operational Impact. Breezy. Slight Chance of SHRA...SHSN. Sunday: Low Operational Impact. Breezy. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Monday: Low Operational Impact. Slight Chance of RA. Monday Night: Moderate Operational Impact. Chance of RA. Tuesday: High Operational Impact. Likely RA. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Speciale NEAR TERM...Speciale SHORT TERM...Speciale LONG TERM...Frugis AVIATION...Frugis