NEAR TERM /THROUGH SUNDAY NIGHT/
Regional radar shows most shower and thunderstorm activity outside the forecast area this evening. An isolated shower remains possible across Allegany county and near the Lake Ontario shoreline of Niagara and Orleans county this evening.

Tonight...high pressure centered over the Ohio valley will slowly drift east and expand across the Lower Great Lakes. After a few early evening showers/storms across the Srn Tier...the sfc high will help to promote fair dry weather
While mild
the mins tonight will be a few degrees lower than those from early this morning as they will range from the upper 50s across much of the Srn Tier to the lower 60s most elsewhere. Valley fog is possible across the western Southern Tier and Black River valley south of Lowville overnight.

High pressure over the region Sunday and Sunday night will then guarantee nice weather to end the weekend. The mercury will generally top out in the lower 80s on Sunday with mins in the upper 50s (Srn Tier/Lewis co) to lower 60s Sunday night.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
Weak surface high pressure under a broad mid-level ridge will gradually pull east of the region Monday. While this will maintain the mostly dry pattern into Monday night, a mid level warm front will lift into central NY from the south between Monday evening and Tuesday morning. An uptick in synoptic moisture advecting northward with the front combined with diurnal instability could touch off an isolated shower or thunderstorm, mainly in the vicinity of the Finger Lakes region. Otherwise, Monday will be quite warm though not overly humid, with highs in the mid to upper 80s, a few readings in the low 90s in the typical warm spots in the Genesee Valley.
Lows Monday night will range in the mid to upper 60s in most areas.

Much more unsettled weather expected Tuesday as broad longwave troughing to the west over the Great Lakes slowly encroaches on the forecast area. An attendant area of surface low pressure crossing from the upper Great Lakes to Quebec across southern Ontario will send a cold front towards the region from the northwest, causing downstream convection through the course of the day. Chances will be greatest in the afternoon during peak diurnal heating, though overall shower/storm coverage is more uncertain here...As there will be a notable lack of low-level jet support or height falls aloft to focus or increase general coverage of storms through the day. There will also likely be other factors that will come into play Tuesday, such as the tightening mid-level thermal gradient leftover from the earlier warm front, in addition to any lake-induced boundaries that develop. In any case, PWATs climbing between 1.5 and 2 inches could still support a few locally heavy downpours Tuesday into Tuesday night.

Any convection should begin to wind down after midnight Tuesday night, especially over the western counties as drier air begins to work in along the upstream cold front. A lower end chance for showers/thunderstorms will linger overnight as the main longwave trough remains upstream over the Great Lakes. Model guidance begins to diverge more significantly here though, especially the latest 12z GFS which now indicates the trough ingesting some moisture from the remnants of TS Beryl and advecting it into the region. At this juncture will label this an outlier solution as it is in sharp contrast to the latest CMCNH/ECMWF, but something to keep an eye on with future updates. Temperatures will be a couple of degrees cooler Tuesday night compared to Monday night, with a larger range of 60s for overnight lows.

LONG TERM /WEDNESDAY THROUGH SATURDAY/
As this period opens on Wednesday...there has been at least some increase in spread on how quickly the initial trailing cold front from Tuesday's system exits our region...with the 12z GFS notably slower and wetter compared to both its previous continuity and the other medium range packages...and now offering a fairly rainy day for at least areas south of Lake Ontario
In contrast
the GEM/old 00z ECMWF already have this boundary through our region by the start of Wednesday morning...and still attempt to pivot a much weaker secondary cold front across our area through the course of the day...with pcpn ranging from lighter/spottier to largely nonexistent. Given the outlier nature of the 12z GFS and its rather abrupt break from its own continuity...will not quite buy into it just yet and instead will continue to lean more towards the latter packages and our own continuity for now...with the secondary cold front and broad troughing aloft supporting the potential for some additional scattered showers/isolated storms during Wednesday.
Generally drier weather should then follow for Wednesday night as surface-based ridging and drier air noses across our region.
Otherwise cooler and more comfortable air will filter back across our region following the passage of the above cold fronts...with highs Wednesday pulling back to the upper 70s/lower 80s...and lows Wednesday night in the lower to mid 60s.

After that forecast uncertainty increases as we work through the rest of this period...as the various guidance packages are struggling with their handling of the remnants of Tropical Cyclone Beryl and their interaction with the next mid level trough pushing east from the Plains States. The above in turn greatly influence where the departed main frontal zone stalls out to our south...and then exactly how far northward this boundary returns and when it does so as one or more weak waves of low pressure ripple along it later on in the week.

Given the above and the resultant decrease in forecast confidence...
have leaned more heavily toward blended guidance later on the week...albeit with slightly higher chance PoPs Friday into Saturday where there is at least some semblance of agreement on a surface wave passing near or over our region. With PWATs potentially rising to around 2 inches around that time owing to the injection of some tropical moisture...there could be at least some potential for locally heavy rainfall late in the week
Otherwise
temperatures should average out a bit above normal Thursday through Saturday...with daily highs mainly in the 80s and nightly lows largely in the 60s.

AVIATION /23Z SATURDAY THROUGH THURSDAY/
VFR conditions will continue across the eastern Great Lakes region this evening. Surface high pressure will move into the region tonight through Sunday. Only hiccup might be fog development across valley locations across the western Southern Tier and Black River valley south of Lowville.

Dry weather with some VFR diurnal cumulus expected through Sunday.

Outlook...

Monday...VFR.
Tuesday...Restrictions possible with showers and thunderstorms likely.
Wednesday...Restrictions possible with a chance of showers and thunderstorms.
Thursday...Mainly VFR with a low chance of showers and thunderstorms.

MARINE
High pressure will build over the lower Great Lakes tonight into the start of next week. This will bring a period quiet conditions through mid week with a weak pressure gradient favoring light winds and limited waves. The light flow will allow for some local lake breezes to form each day.

BUF WATCHES/WARNINGS/ADVISORIES
NY...None.
MARINE...None.