Area Forecast Discussion
Issued by NWS Albany, NY

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000 FXUS61 KALY 231048 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 648 AM EDT Mon May 23 2022 .SYNOPSIS... Fair weather is expected today into Wednesday with high pressure in control. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... High pressure gradually building into our region from the west and the tight thermal gradient on the leading edge of deeper cold advection will track through our region this morning. The low level forcing and lingering boundary layer moisture will support intervals of clouds and sun with increasing sunshine through the afternoon. Lots of high clouds well in advance of the system in the SE U.S. also streaming into our region and will continue through tonight. So, north to northwest winds, cooling at the boundary layer and a mix of clouds and sun will limit heating somewhat today. Highs in the upper 60s to lower 70s with around 60 to mid 60s higher terrain. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Low level ridging continues to build into our region tonight and Tuesday and low level winds will trend to light to calm. considerable high clouds are expected tonight but there will be periods of thinning high clouds, especially along and north of I-90. By Tuesday morning, much of the high cloudiness should be confined to the mid Hudson Valley and NW CT, if even that far north. So, some intervals of thin high clouds over most of the region should allow for more sun than clouds. Temperatures should reach the upper 60s to lower 70s with mid 60s higher terrain. There are hints in sources of guidance/ensembles for a weak wind shift boundary to drift north through our region later tonight through Tuesday as high pressure shifts east of our region and weak boundary layer warm advection begins. The northward drifting weak wind shift boundary is expected to shift low level winds to light southeast to south. Low level dew points will begin to slowly rise as well. So, there are uncertainties on whether low clouds will develop in response to the weak boundary and increasing low level moisture tonight through Tuesday. Indicating intervals of clouds Tuesday and Wednesday with highs both days in the upper 60s to lower 70s. It could be a degree or two warmer, especially Wednesday, if there is more sun and less clouds. Lows Wednesday night with increasing clouds well ahead of the next upper energy and associated cold front, in the upper 40s to lower 50s. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Main forecast challenges for the long term are focused on the Thursday night to Saturday period as an upper level trough from the Midwest and associated surface cold front track eastward resulting in a chances for showers and possible thunderstorms. Depending on if the parent trough cuts off, unsettled conditions may linger into Sunday but trends point to improving conditions. Otherwise, temperatures remain seasonable or slightly above normal through the majority of the period. Read on for details. We start off the long term on Thursday with surface high pressure sliding off the East Coast with southwest flow in place aloft over the Northeast as a surface warm front attempts to push northward through the region. In response to surface winds out of the southeast ahead of the incoming front, temperatures Thursday look to be seasonable or slightly cooler than normal due onshore flow. In addition, guidance hints that a weakening disturbance from the Gulf Coast States could get caught within the southwest flow and push northward into the Northeast. Since guidance shows potential for this system to result in some weakened showers for areas south of I- 90, we continue to show slight chance and chance POPs. By Thursday night, the warm front should be north of our area with the associated warm sector spreading into eastern NY and western New England. Temperatures Thursday night should be rather warm as a result with the humidity also rising. We will remain in the warm sector on Friday as the surface cold front tracking eastward. At this point, important discrepancies in the 500hPa pattern result in different solutions for the rest of the Memorial Day Holiday. The 00 UTC ECMWF suggests a northern stream shortwave tracking through the Canada Prairie Provinces phases with a neutrally tilted southern stream shortwave trough over the Upper Midwest Thursday night. As a result, the phased shortwave rides up and over the downstream ridge with the sfc cold front and trough both tracking through the Northeast during the day Friday. With a rather clean exit Fri night, high pressure builds back into the region for Saturday suggesting a dry and warm start to the holiday weekend. On the other hand, the CMC and GFS paint a more pessimistic picture, suggesting the northern stream trough in south central Canada outruns the southern stream trough and, as a result, the two fail to phase. With strong downstream ridging still in place over the western Atlantic, the southern stream wave slows down and matures into a closed low before arriving in the Northeast Friday night or Saturday. Not only does this enhance precipitation along the incoming surface cold front but both the GFS and CMC suggest the front could linger into Saturday. This would keep chances for rain and possible thunderstorm in the forecast. The GFS ensembles indicate a wide variety of solutions, both wet and dry, but the GEFS show negative height anomalies lingering into Saturday. While this is still a low confidence forecast, we collaborated with neighboring offices and decided to linger chance POPs in Saturday before showing improving conditions by Sunday and especially Monday. && .AVIATION /12Z MONDAY THROUGH FRIDAY/...
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VFR conditions at all TAF sites will remain in place through the end of the TAF period. Southwest flow aloft will allow high clouds to continue spreading northeastward from the mid- Atlantic over the TAF sites through the day resulting in SCT-BKN clouds at or over 20kft. North-northwest winds today will shift to the north-northeast by 15 - 18 UTC and will remain a bit breezy sustained near 5 - 12kts through sunset. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. NO SIG WX. Wednesday Night: Low Operational Impact. Isolated SHRA. Thursday: Moderate Operational Impact. Breezy. Chance of SHRA. Thursday Night: High Operational Impact. Likely SHRA. Friday: High Operational Impact. Breezy. Likely SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA. Saturday: Low Operational Impact. Slight Chance of SHRA.
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&& .FIRE WEATHER... Fair weather is expected today into Wednesday with high pressure in control. RH values will drop to the 35 percent to 45 percent range this afternoon, then increase to above 65 percent tonight. RH values drop again to the 35 percent to 45 percent range Tuesday afternoon. North to northwest winds to day increasing to around 15 mph, then become light tonight. WInds Tuesday become southeast to south at less than 15 mph. The fair weather will continue into mid-week with unsettled weather for the latter part of the week. && .HYDROLOGY... No hydrologic concerns are expected through at least the first half of this week with fair weather expected. Unsettled weather returns for the latter part of the week. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...NAS NEAR TERM...NAS SHORT TERM...NAS LONG TERM...Speciale AVIATION...Speciale FIRE WEATHER...NAS HYDROLOGY...NAS is the U.S. government's official web portal to all federal, state and local government web resources and services.