Area Forecast Discussion
Issued by NWS Albany, NY

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000 FXUS61 KALY 280545 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 1245 AM EST Sun Feb 28 2021 .SYNOPSIS... Dry weather will return to the area tonight as high pressure builds into the area. Another system will move across the region later Sunday with periods of rain and perhaps a wintry mix across the higher terrain. A strong cold front will cross the area later Monday, possibly accompanied by some snow squalls and followed by much colder temperatures. && .NEAR TERM /THROUGH TODAY/... As of 1240 AM EST...Latest Nighttime Microphysics satellite imagery shows a wide range of cloud coverage across the area. Lake-induced stratus is holding strong across the Adirondacks and western Mohawk Valley. High clouds are slowly streaming northward across southern areas. Elsewhere, just some patchy low level and high cirrus clouds are in place. As a result, temperatures vary as well with values remaining elevated across the Adirondacks and Mohawk Valley due to the cloud cover and are dropping where the winds have gone light. Where a breeze lingers (especially along the Mohawk Valley into the Capital District and Berkshires), temperatures remain up. So, quite a few adjustments to temperatures and cloud cover for this update. Expect low temperatures to range from the mid- 20s to lower 30s. Dry weather is expected through the night, though some patchy fog will develop in localized locations where there is enough of a clear sky and light wind present (as already evidenced by the KPOU and KGFL obs). Previous Discussion: Clearing has occurred in some areas with clouds anchored to terrain in the southern Adirondacks, southern Green Mountains, the Berkshires and NW CT. The clouds will gradually decrease in coverage as high clouds spread over our region through tonight ahead of the next system. The mid Hudson Valley has cooled into the lower 30s due to light winds but high clouds are rapidly spreading over the region and should slow or stop temperatures from falling much there. The rest of the region is warmer but as lower clouds decrease in coverage and winds trend to light, temperatures will fall elsewhere. Steady surface winds from the west and northwest this evening should trend to light or calm toward daybreak. Some patchy fog could form in areas that see the most clearing. Fog should not be widespread or dense enough to mention in forecast. Some minor adjustments to temperatures and sky cover through the night. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... The next wave of low pressure will approach our area on Sunday. This next system looks to be a combination of two unphased waves; one approaching from the Great Lakes and one from the Tennessee Valley. Model consensus is good that the heaviest precipitation associated with the Tennessee Valley wave will track just south of our area, while precipitation associated with the northern branch wave will be heaviest to our north and west. Despite this split in the pattern, it looks like at least some light precipitation will be overspreading the area Sunday afternoon and continuing Sunday night. With the timing of the precipitation not until later Sunday, all areas should be above freezing before the onset of the precipitation and the p-type with this next system should be mostly rain. A little wet snow could mix in over higher higher elevations north and west of the Capital District, but no accumulations are expected. Periods of light rain will be widespread across the area Sunday night as this unphased system crosses the area. After the passage of these waves, there should be some clearing early Monday as weak cold advection develops. Temperatures will likely recover into the upper 30s and 40s in this pattern by early Monday afternoon, then a strong cold front will approach from the northwest later Monday. West-southwest winds will increase ahead of this system, and will likely become quite gusty before shifting to the northwest Monday evening. In addition, some snow showers will likely develop west of the Hudson Valley Monday afternoon, and could intensify into heavier squalls late in the day or Monday evening. Models are indicating some instability ahead of this system and with surface temperatures likely to reach the 40s just ahead of the front some small amounts of CAPE appear to be possible. The best chance for up to 2 or 3 inches of snow with this system will likely be over the western Mohawk Valley and southwest Adirondacks, but one or two squalls could reach as far east as the Capital District Monday evening and this will have to be watched. The cold front will be followed by blustery and much colder weather later Monday night. The flow appears to have enough of a northerly component behind this front so that most of the lake effect will shift into central NY rather quickly overnight, so that no major accumulations are expected for our areas east of Lake Ontario. && .LONG TERM /TUESDAY THROUGH SATURDAY/... A fairly benign weather pattern is upon us as we head into the long term period. We begin on Tuesday with an anomalously cold airmass in place. The latest GEFS 850mb temps of -20 to -25C are 2 to 3 standard deviations below normal. This should translate to high temps below freezing area-wide (teens in the southern Dacks). In addition to the chilly temps, winds will also be gusty out of the northwest. So despite plentiful sunshine, temps will feel quite chilly throughout the day. The upper trough responsible for the cold airmass departs by Tuesday night with a general zonal flow setting up across the northeast. A northern stream trough looks like it will stay set up across Quebec and at times dip down into New York and New England throughout the remainder of the long term period. This may lead to a period of light lake effect snow showers downwind of Lake Ontario on Thursday. But all of the southern stream energy is progged to stay south of our region and therefore, looks like a mostly dry forecast. Temperatures will be above normal Wed-Thur, with highs in the mid 30s to mid 40s. A brief return to seasonable temps is expected Fri- Sat as the upper trough dips south, but temps return to above normal by the end of the weekend. Overnight lows will be the coldest of the period Tuesday night with temps in the single digits to upper teens. Lows for the remainder of the long term period look fairly seasonable. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... System that brought the rain has departed and much of the cloud cover has lifted above 3000 feet and in some areas has cleared. Only KGFL is seeing some MVFR visibilities as the wind shift and steady winds have not cleared out the fog yet. Based on satellite and radar trends, intervals of clouds above 3000 feet and partial clearing through daybreak at all sites. Fog should lift at KGFL later this evening but during periods of clearing, as winds diminish to light to calm later this evening and through the night, some intervals of MVFR visibilities in fog are possible, especially between 08Z-12Z but as early as 04Z at KGFL. After about 12Z, just intervals of high clouds well above 10000 feet until afternoon when the next storm system approaches. Some showers could begin to affect areas around KPOU and KPSF after 18Z Sunday. Winds will be west to northwest at 10 Kt or less at KGFL and KPOU but around or just above 10 Kt at KALB and KPSF this evening, with some gusts around 20 Kt. Wind shear is being indicated at all TAF sites through about 02Z-04Z until the strong west to northwest winds at around 40 Kt aloft exit by that time. Winds diminish to less than 6 Kt by daybreak and light winds continue through Sunday morning. Winds become southeast at 6 Kt or less Sunday afternoon. Outlook... Sunday Night: Moderate Operational Impact. Chance of SHRA. Monday: Low Operational Impact. Breezy. Slight Chance of SHRA. Monday Night: Moderate Operational Impact. Windy With Gusts To 31 kts. Chance of SHSN. Tuesday: Low Operational Impact. Breezy. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. && .HYDROLOGY... No major hydrologic issues are foreseen through the middle of next week. Some melting and sublimation of the snowpack in the valleys is expected during the day time over the next several days. NERFC forecasts show minor up and down changes in river flows due to the diurnal freeze/thaw cycle. River ice is not expected to break up over the next several days. Low pressure tracking across the area later Sunday and Sunday night will bring mainly rain. Total QPF for this system will range from 0.10 to 0.30 of an inch. A strong cold front with snow showers is expected to move through later Monday through Monday night. Much colder air returns Monday night and Tuesday. 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...MSE NEAR TERM...MSE/NAS/Rathbun SHORT TERM...MSE LONG TERM...Wasula AVIATION...NAS HYDROLOGY...NAS/Rathbun is the U.S. government's official web portal to all federal, state and local government web resources and services.