Albany Office Forecast Discussion
000 FXUS61 KALY 011936 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 336 PM EDT Fri Jul 1 2022 .SYNOPSIS... With warm temperatures in place, there could be a few spotty showers or thunderstorms around this evening. Showers and thunderstorms will become numerous for the late night hour tonight and into Saturday ahead of a cold front. Some thunderstorms on Saturday afternoon could be strong for southern parts of the area, with gusty winds being the main threat. Dry weather, with seasonable temperatures and fairly comfortable levels of humidity is expected for Sunday into Monday before the threat of showers and thunderstorms returns for Tuesday. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... As of 336 PM EDT...A large closed off upper level low is located over Hudson Bay Canada and is mostly spinning in place. Subtle upper level trough axis is now located over the Upper Great Lakes and this is slowly shifting eastward. Our region continues to be located within a warm sector on an approaching frontal system. Surface warm front is located over Quebec and New Brunswick Canada, while the slow moving surface cold front is upstream of the area over the eastern Great Lakes. This cold front has been slowing down its eastern progress today and will only be slowly heading into western New York for tonight. Meanwhile, a large high pressure area is located over the western Atlantic Ocean. The south to southwest flow has been downsloping over the high terrain, which has resulted in both boosted high temps and also locally lowered dewpoints thanks to the deep mixing. Visible satellite imagery continues to show some narrow bands of high cirrus clouds moving west to east across the area. Some scattered diurnally-forced cumulus is also around, mainly for the higher terrain. A more concentrated band of clouds associated with a pre-frontal trough is located over western and central New York and these will be spreading into western areas over the next few hours. With the approaching upper level trough and surface cold front, SPC Mesoanalysis is showing 0-6 km bulk shear of 30 to 40 kts across the area. SBCAPE values have increased to 500 to 1000 J/kg over much of the area, with some localized higher amounts. MLCAPE values remain fairly low, with the best MLCAPE located south over the mid Atlantic states stretching into the mid Hudson Valley and NW CT. Low-level lapse rates are fairly steep due to the strong heating today, with mid level lapse rates remain poor (around or under 6 deg C/km). The best large-scale forcing is still well off to the west over the Great Lakes. Over the next few hours, the pre-frontal trough could allow for a few isolated showers or thunderstorms to develop over central New York and these could spread eastward into our area after 6pm or so. Based on the latest CAMs, from about 6 pm through midnight, some isolated showers or t-storms can`t be ruled out. Coverage looks fairly spotty and storms won`t last long, as the limited forcing, lack of moisture, weak instability and poor mid level lapse rates won`t allow for storms to grow too tall or last very long. However, strong low-level lapse rates and high DCAPE is in place, so can`t totally rule out a locally strong wind gust with a collapsing cell, but this would be highly localized. SPC has removed the marginal risk from our area and this makes sense considering the limiting factors in place. Any of the storms would be spreading from the west, as the activity over PA/MD will be dissipating as it heads east-northeast towards NJ. Behind this initial activity, a more widespread area of showers and embedded thunderstorms is expected for the overnight hours, from about midnight through daybreak. Nocturnal effects should allow for limited instability and a low-level inversion to form, so there`s no threat for any strong wind gusts overnight. Some locally heavy downpours can`t be ruled out with PWAT values rising above 1.50 inches, but strong mid-level flow should keep heavier rainfall moving along fairly quickly. Based on guidance, highest POPs/QPF looks to be across the northern half of the area, as the surface cold front continues to get closer to the region from the northwest. Overnight lows will only fall into the mid to upper 60s for most locations. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... On Saturday, the cold front will be crossing from northwest to southeast through the area. The initial activity from the overnight hours will be departing after daybreak and most of the morning should be fairly quiet as the front slowly shifts southward across northern parts of the area. As instability builds south of the front, some renewed showers and thunderstorms look to occur for the southern half of the area (Capital Region on southward) for the afternoon through early evening hours. 12z SPC HREF shows SBCAPE values around 1000 J/kg for southern areas, along with strong mid-level flow around 40 kts or so. This could result in a few strong to severe storms, with damaging winds being the main threat. SPC continues the slight risk for far southern areas for tomorrow. The threat should be over by about 5 to 7 PM, as the front moving southward across the area ends the threat for storms as it moves through. Temps will vary on Saturday. While northern and high terrain areas will stay in the 70s, southern and valley areas will be in the low to mid 80s. Dewpoints will be well into the 60s ahead of the front, but will fall into the 50s with the passage of the front and wind switching around to the west. Behind the front, cooler, drier and less humid air is expected through the rest of the Holiday Weekend with lower heights, surface high pressure and cooler temps aloft moving in. Lows will fall into the mid 50s to mid 60s for Saturday night. On Sunday, high pressure will allow for plenty of sun, although dewpoints will be comfortable in the 50s (some 40s across the high terrain). Temps will reach the mid 70s to mid 80s across the area with lows falling into upper 40s to mid 50s for Sunday night with a mostly clear sky. && .LONG TERM /MONDAY THROUGH FRIDAY/... The long term period will favor west to northwesterly upper-level flow with occasional shortwave troughs passing through the flow. This, overall, will prevent any high heat or humidity from returning and overall seasonable weather conditions for early July. We will be located on the western half of a surface high pressure system for the Fourth of July which will support another dry day. Our next chance of rain will not arrive until later Monday night through Tuesday as a low pressure system passes across the region from the west. A warm front looks to be positioned along or just north of I-90 Monday night where there is better model agreement for an overnight MCS to track along that front toward our region. There is still some uncertainty with the actual track of this feature, but will place the higher pops along and north of I-90 for Monday night at this time. By Tuesday afternoon and evening, a cold front will begin to push southward where enough forcing and instability could result in showers and thunderstorms, mainly favoring areas ahead of the front. Models are trending toward a drier Wednesday as the cold front pushes southward into the mid-Atlantic and surface high pressure nudges southward from Canada. Therefore, we reduced NBM pops to signal that most of the area will escape with a dry day. The later part of the week will result in high pressure departing to the east as southerly low-level flow resumes with chances for at least isolated to scattered showers and thunderstorms returning, mainly during the afternoon and evening hours. Temperatures will run near seasonable levels throughout the week with highs ranging from the upper 60s to mid-70s across the higher elevations to the upper 70s to mid-80s in the valleys each day. Lows each night will dip into the 50s and 60s, though a few locations in the higher elevations could fall into the 40s on some nights. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... Through 18z Sat...diurnal cumulus are building early this afternoon, but with drier air mixing in from above, instability is limited. As a result, we do not expect much if any shower/storm activity during the daylight hours. VFR conditions should prevail. There is a slight chance that an isolated shower or storm could develop around 00-03Z, but chances are too low to include in the TAFs at this time. An area of showers and embedded thunderstorms is expected to approach ahead of a cold front, with rainfall mainly within the 06-12Z window. The PROB30 window was pushed back in time to encompass this time frame with the 18Z TAF package. VFR conditions are still expected to prevail, but MVFR cigs/vsbys will be possible in and after any heavier downpour or thunderstorm, with brief IFR vsbys not ruled out. Most of the rain should be done by 12-13Z, but a few showers could linger. Brief MVFR cigs may linger for an hour or two after 12Z, but VFR is expected to prevail for the most part. Additional redevelopment of showers and thunderstorms is possible toward the end of the TAF period along the cold front at KPSF/KPOU, but uncertainty on timing and coverage precludes a mention in the TAFs at this time. Winds will be from the south to southwest gusting to around 20 kt for the remainder of the afternoon. The winds will become southerly at around 5 kt overnight before becoming 5-10 kt from the west to southwest after 12Z Sat. Outlook... Saturday Night: No Operational Impact. NO SIG WX. Sunday: No Operational Impact. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Independence Day: No Operational Impact. NO SIG WX. Monday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Tuesday: Moderate Operational Impact. Scattered SHRA...TSRA. Tuesday Night: Moderate Operational Impact. Scattered SHRA. Wednesday: Low Operational Impact. Isolated SHRA. && .FIRE WEATHER... Lines of showers and thunderstorms will pass over the region for tonight into Saturday. While some areas will see a wetting rainfall, it is not guaranteed that everywhere will see it. Behind this frontal boundary, dry weather will return for Sunday into Monday. The next chance for showers and thunderstorms will be during the day on Tuesday. RH values will be near 100 percent within showers and thunderstorms for tonight into Saturday morning. Behind the departing front, RH values will drop as low as 35 to 60 percent from north to south on Saturday afternoon. Southerly winds around 5 to 10 mph tonight will become westerly around 10 mph by late in the day on Saturday. RH values will be as low as 35 to 45 percent on both Sunday and Monday afternoons. Westerly winds will be 5 to 10 mph on Sunday and around 5 mph on Monday. && .HYDROLOGY... Some isolated showers and thunderstorms are possible this evening, although more widespread showers and thunderstorms are expected tonight into tomorrow as a frontal boundary settles southwards across the region. Rainfall amounts within showers and thunderstorms will be highly variable. While basin average amounts look to be around a quarter to a half of an inch, localized point totals up to an inch are possible. While this rainfall may allow for brief ponding in urban or low lying areas, the recent dry weather makes this rainfall much needed and few hydrologic issues are anticipated through the weekend, as dry weather will then return for Sunday into Monday. Some more showers and thunderstorms will be possible on 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...Frugis NEAR TERM...Frugis SHORT TERM...Frugis LONG TERM...Rathbun AVIATION...Thompson FIRE WEATHER...Frugis HYDROLOGY...Frugis