Area Forecast Discussion
Issued by NWS Albany, NY

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000 FXUS61 KALY 180527 AFDALY Area Forecast Discussion National Weather Service Albany NY 127 AM EDT Mon Sep 18 2017 .SYNOPSIS... High pressure will control our weather through Monday night with mainly dry weather, above normal temperatures and humid conditions. Hurricane Jose will slowly be moving north towards the Northeast early next week with an increasing threat of some showers late Monday night through Wednesday. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Fairly solid stratus cloud deck has moved across much of Litchfield and eastern Dutchess counties. Looking at the fog channel on satellite it appears to be creeping north and westward and should expand move into the mid Hudson Valley and into the Taconics later tonight. This will keep lows a bit milder than Sunday night and also reducing the areal extent of dense fog in these areas. Satellite fog product shows river valley fog also forming. Will have to watch trends to see how far north and west stratus clouds expand. It is possible that it eventually extends into the Capital Region closer to, or shortly after daybreak. Low temperatures should range from the mid 50s to the lower 60s. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/... Quite a stable long wave pattern across the U.S. with upper ridging in the east and still some very weak lingering upper energy over southern areas that could support an afternoon isolated shower once again from the eastern Catskills through the mid Hudson Valley and NW CT to the southern Berkshires. Highs Monday in the 80s but around 80 in higher terrain. There are hints that a low level boundary currently in the Great Lakes makes an approach to the U.S./Canadian border late Monday night into early Tuesday but the upper ridging in the eastern U.S. is likely to keep the low level boundary north of our forecast area. The hurricane offshore the east coast is expected to slowly build northward and the low level pressure gradient will tighten just a little over the northeastern U.S. as these features approach from the northwest and the south. Some intervals of high clouds may spread into the region as well later Monday night. So low temperatures may be a degree or two warmer Monday night with just a light wind potentially limiting coverage of river, lake and swamp fog. Again, that depends on whether there are high clouds and a very light wind and that is yet to be seen. Lows Monday night in the 60s with some 50s northern areas. There may be an isolated shower in the mid Hudson Valley and NW CT by daybreak Tuesday depending on how close the hurricane gets by that time. Still considerable uncertainty as to the track of the hurricane but regardless of the specific track, there is a broad consensus in guidance and ensembles for the wind and moisture fields to expand northwest from the center, bringing thicker clouds and chances for rain from the mid Hudson Valley through NW CT, Berkshires and southern VT. A slight chance for rain should extend northwest through the rest of the region. Highs Tuesday in the 70s but around 70 in the southern Green mountains, Berkshires and NW CT. Winds may get breezy in the mid Hudson Valley, NW CT and the Berkshires but there is conflicting guidance as to how far northwest the stronger winds get with considerable winds indicated at 925 hPa and 850 hPa but much less 2m wind. Trends in the winds and the potential for mixing of stronger winds from 925-850 hPa to the surface will be watched closely. Sources of guidance and ensembles broadly suggest the hurricane trends east and north by Tuesday night and Wednesday but again, the northwestern extent of thicker cloud cover, rain chances and winds is very uncertain. Any persistent north to northeast winds could help temperatures fall into the upper 50s to mid 60s, especially if there are areas of thinner high clouds and less coverage of rain. Gradually reducing the chances for rain through Wednesday with highs in the 70s but around 70 higher terrain. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... The exact track of Tropical Cyclone Jose will have implications on our extended outlook but at this time, it looks like Jose by 00z Thursday should be near or just northwest of the 40N/70W benchmark with high pressure building into the Northeast from Canada. Most of the guidance shows Jose slowly shifting out to sea just off Cape Cod as high pressure takes control of the Northeast heading into Thursday. Depending on exact timing/placement of Jose as it exits and the high building in from Canada, far eastern and southern zones could see a few lingering showers Wednesday night. Thus, have slight chance POPs in these areas which lines up with the neighboring WFOs. By daytime Thursday, confidence leans with a primarily dry forecast despite some early clouds potentially in southern/eastern areas as Jose pulls out to sea. The pressure gradient between the 1020-1025mb building Canadian high and an exiting Jose could lead to breezy conditions for daytime Thursday with gusts 15-20mph, especially southern/eastern areas along with seasonable temperatures in the 70s thanks to northerly winds and cooler air wedging into our area. For Friday to Sunday, guidance is in good on the longwave pattern across the lower 48 with a deepening trough in the western US and a resulting strengthening ridge downstream in the East. For the exact track of Jose during this period, please refer to the National Hurricane Center`s official forecast. Due to the strengthening ridge over the Northeast, temperatures for the end of next week into next early week look to rise well into the 80s with H850 isotherms reaching +15-18C which is 1-2 standard deviations above normal. In addition, we should see an extended period of sunny and dry conditions. && .AVIATION /05Z MONDAY THROUGH FRIDAY/... High pressure will slowly move east of the TAF sites overnight into Monday. Tricky call on extent of radiational fog development and/or stratus overnight. Latest GOES-16 10.3-3.9 IR and surface obs depict low stratus deck expanding north and west from southern CT and the lower Hudson Valley. It is possible that this cloud deck eventually reaches KPOU/KPSF between 04Z-08Z/Mon, reducing Cigs to IFR/LIFR but perhaps tempering fog formation. These low clouds could eventually reach KALB closer to 12Z. So, although have indicated IFR Vsbys at these sites overnight, did not go quite as low as 1/2SM, thinking that low stratus may take hold before lower Vsbys develop. Better chance of LIFR Vsbys at KGFL. Low clouds and/or fog with associated IFR conditions may linger until at least 13Z-15Z/Mon, before slowly improving to MVFR, then eventually VFR by Monday afternoon. The winds will be mainly calm overnight through mid morning Monday, then should become southeast to south at 4 to 8 Kt in the afternoon. Outlook... Monday Night: No Operational Impact. Chance of RA. Tuesday: Moderate Operational Impact. Chance of RA. Tuesday Night: Moderate Operational Impact. Chance of RA. Wednesday: Moderate Operational Impact. Slight Chance of RA. Wednesday Night: No Operational Impact. Slight Chance of SHRA. Thursday: No Operational Impact. NO SIG WX. Thursday Night: No Operational Impact. NO SIG WX. Friday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... High pressure will control our weather through Monday night with mainly dry weather, above normal temperatures and humid conditions. Hurricane Jose will slowly be moving north towards the Northeast early next week with an increasing threat of some showers late Monday night through Wednesday. The min RH values will be 55 to 70 percent Monday afternoon and 65 to 85 percent Tuesday with possible rain and the higher RH values in the mid Hudson Valley, NW CT, Berkshires and southern VT. The RH values will be 80 to 100 percent tonight and Monday night. Light and variable in direction winds of less than 15 mph will occur through Monday. North to northeast winds will increase to around 15 mph Monday night and Tuesday with some gusts to 20 mph possible Tuesday afternoon in the mid Hudson Valley, NW CT and parts of the Berkshires. && .HYDROLOGY... No widespread rain is expected through Monday night. Isolated showers could produce point rainfall of a tenth of an inch or less this evening and Monday afternoon. The track of Tropical Cyclone Jose will determine the extent of any rainfall getting into Albany HSA Tuesday into Wednesday. Currently, the official NHC track of Hurricane Jose is well offshore. However, it is possible locations south and east of the Capital Region could get some light to moderate amounts of rain on the northwest side of the system, with less than half of an inch of rain currently forecast. Drier weather returns to the region on Thursday. 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...IAA/KL/NAS SHORT TERM...NAS LONG TERM...Speciale AVIATION...KL/BGM FIRE WEATHER...NAS HYDROLOGY...NAS

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