388 FXUS61 KALY 242021 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 421 PM EDT Wed Apr 24 2019 .SYNOPSIS... Weak high pressure will bring fair and seasonably mild conditions Thursday before another storm system brings widespread rainfall and cooler temperatures to the region for Friday into Saturday morning. Breezy and chilly conditions will then be in place for the remainder of the weekend. && .NEAR TERM /THROUGH THURSDAY/... Strong low pressure system continues to slowly track into the Canadian Maritimes as we remain under the influence of moist cyclonic flow. This has kept much of the region under cloudy skies today with a large variation in temperatures from the 30s across the Dacks to the low and mid 60s across the mid-Hudson Valley. A weak ridge of high pressure will work its way into the region this evening into the overnight period, resulting in mostly sunny skies and seasonably mild temps for Thursday. Afternoon highs should warm into the mid and upper 60s, with upper 50s to low 60s across the high terrain. Temps overnight tonight will dip into the 30s area wide, something we haven't seen for about a week. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... Clouds will be on the increase again Thursday night as the next storm system approaches the region from the southwest. Return flow will be in place, helping to advect in ample moisture with PWATs forecast to exceed 1 inch. Latest GEFS indicate PWATS +1 to +3 S.D. for Friday into Friday night. Rain will overspread much of the region by daybreak on Friday as a surface low strengthens and tracks along the New York/Canadian border. Looks like there will be an initial surge of moderate to heavy rainfall Friday morning associated with the low track, then a secondary push with a cold front progged to track through the region Friday evening. Still expect rainfall throughout the day Friday but may be a few breaks at times. Total QPF through the event looks to average around an inch with up to 1.25 inches perhaps in the Dacks into southern Vermont. Latest MMEFS shows mainly rises to action stage outside of a few points that are already running high. Will continue to mention this potential flood threat in the HWO due to the variations in max model QPF. Rain will exit to the east Friday night with rain potentially changing over to snow in the highest elevations. Winds will increase from the west, become breezy, with temps cooling into the 30s in the Dacks and lower 40s elsewhere. Saturday will stay cool and breezy under mostly cloudy skies. There may be some light showers that linger in the high terrain as well. Afternoon highs will be in the mid 40s to upper 50s. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... A fairly active weather pattern is expected for late April into early May with multiple short-waves potentially impacting the forecast area in a quasi-zonal to zonal mid and upper level flow late in the weekend and into the early to middle portion of next week. Temps will likely run cooler than normal. Saturday Night into Sunday...High pressure at the sfc and a short- wave ridge briefly builds in Sat night with decreasing winds and tranquil weather with lows falling off into the upper 20s to lower 30s over the mtns, and mid 30s to around 40F in the lower elevations. A quick moving short-wave trough will be approaching from the Great Lakes Region and lower OH Valley for Sunday. Some slight timing differences with the Ensembles /NAEFS and GEFS/ and the latest CMC/GFS/ECMWF, but overall clouds will be quickly thickening and lowering with a chance of showers, and perhaps a little bit of wet snow over the southern Adirondacks with the onset due to the isentropic lift and the differential cyclonic vorticity advection. Highs will run below normal in the mid 40s to mid/upper 50s Sunday night into Monday...The short-wave trough exits quickly Saturday Night. There could be a few snow showers over the higher terrain in the cold advection in the wake of the system and its cold front. Initially breezy and cool/cold conditions will be followed by another potentially brief period of tranquil and fair weather with a sfc anticyclone building in over the Northeast. Lows fall back into the 30s with some mid/upper 20s over the southern Adirondacks, eastern Catskills, and southern Greens, and 30s over the rest of the region. Temps will still likely run about 5-10 degrees below normal across the region to open the week. Monday Night into Wednesday...Uncertainty increases with the forecast heading into the Tue-Wed time frame. Some moisture may over run a boundary south of the region over the Mid Atlantic States for MON night into TUE, and the latest ECMWF has a wave moving along it a bit further north than the GFS and some of the Ensembles. The day could end up cloudy with just a few light showers around especially south of the I-90 corridor. We went with low chance PoPs at night, and a slight chance during the day. A stronger cyclone may eject out of the lower Plains into the Upper MS River Valley and then the western Great Lakes Region for the mid-week with a warm front and a sfc wave bringing a more widespread rainfall for WED-WED night. We kept the trend of chance PoPs here. Temps continue to run cooler than normal for the first couple of days of May. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... Low end VFR will remain in place at ALB and PSF with high end MVFR at GFL through the afternoon thanks to continued cold air advection. Once we lose diurnal heating and boundary layer mixing, ceilings at PSF and ALB could drop a few hundred feet and return back to high end MVFR through 05-06z/25. This may be better handled with a TEMPO group in the next TAF cycle. GFL should remain status quo MVFR through evening. Further south, POU likely will stay mostly clear and VFR through the TAF period. After 06z/25, clearing should ensue leading to VFR ceilings at all TAF sites. PSF may be the last to see VFR ceilings. Breezy westerly winds will continue through 02-03z/25 with gusts up to 20-25KT. Winds will then diminish to less than 10 kt after 03z/25. Outlook... Thursday Night: Moderate Operational Impact. Likely RA. Friday: High Operational Impact. Breezy Pds RA. Friday Night: High Operational Impact. Breezy Likely SHRA...RA. Saturday: Low Operational Impact. Breezy NO SIG WX. Saturday Night: No Operational Impact. NO SIG WX. Sunday: Moderate Operational Impact. Chance of SHRA. && .FIRE WEATHER... Weak high pressure will bring fair and seasonably mild conditions Thursday before another storm system brings widespread rainfall and cooler temperatures to the region for Friday into Saturday morning. Breezy and chilly conditions will then be in place for the remainder of the weekend. RH will then recover to 80-100 percent tonight and Thursday night. RH will then drop to 25-35 percent Thursday afternoon but will be near 100 percent Friday afternoon with rain showers. Winds will be west to northwest at 15-25 mph this afternoon with gusts of 25-35 mph. These winds will become light/variable after midnight. Light/variable winds Thursday morning will become south to southwest at 5-10 mph in the afternoon. && .HYDROLOGY... Flood Warning remains in effect on the Schroon River at Riverbank. The Schroon River at Riverbank will continue to gradually fall and is forecast to go below 8 feet, moderate flood stage, by around 7 AM Thursday. Please visit our Advanced Hydrologic Prediction Service /AHPS/ web page for specific area rivers and lakes observations and forecasts. Mainly dry conditions are expected through Thursday evening. Another storm system is expected to bring widespread rainfall to the region early Friday morning into early Saturday morning. Looks like total QPF from this system will average from 0.75 inches to 1.25 inches area wide. This may result in renewed river rises late Friday into the upcoming weekend, especially across portions of the Adirondacks into the Mohawk Valley where river levels are already running high from recent rainfall and snowmelt. However, the latest MMEFS shows mainly within bank rises across these areas with the exception of Riverbank and Hinckley Dam which could rise into at least minor flood stage on Saturday. Trends will need to be watched closely, and if this potential for heavy rain increases further, then a Flood Watch may be issued. Please visit our Advanced Hydrologic Prediction Service /AHPS/ web page for specific area rivers and lakes observations and forecasts. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...JLV NEAR TERM...JLV SHORT TERM...JLV LONG TERM...Wasula AVIATION...Speciale FIRE WEATHER...JLV HYDROLOGY...JLV