Area Forecast Discussion
Issued by NWS Buffalo, NY
Issued by NWS Buffalo, NY
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580 FXUS61 KBUF 020800 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 400 AM EDT Tue Jul 2 2024 .SYNOPSIS... High pressure over New England will supply us with another nice day as sunshine through high clouds will be accompanied by comfortable temperatures and low humidity. A deepening southerly flow between the exiting high pressure and an approaching cold front will then allow mid summer heat and humidity to return on Wednesday. Showers and thunderstorms...many with drenching downpours will then make their way into our region later Wednesday and Wednesday evening. && .NEAR TERM /THROUGH WEDNESDAY/... Temperatures more typical of the second half of September will greet early risers this morning...otherwise high pressure exiting across New England will guarantee us another nice day. Unlike yesterday (Monday) though...cirrus blowoff from an MCS over Wisconsin will shroud the sun with a fair amount of cirrus. This will mainly be the case during the midday and afternoon with the cirrus being the thickest near and east of Lake Ontario. Otherwise...it will be a little warmer today...yet still quite comfortable with continued low humidity. Weak warm advection will allow our afternoon temperatures to return to within a couple degrees of 80. While fair dry weather will remain in place tonight...a warm front will push through overnight. This will be marked by relatively thick mid and high level cloud cover...once again focusing on areas near and east of Lake Ontario. The frontal passage will guarantee a noticeably warmer night. After two nights that were more typical of early Fall...our mercury for most areas tonight will only drop into the mid and upper 60s...an increase of roughly 15 degrees from recent nights. Wednesday is then GUARANTEED to be very warm and moderately humid... as a deepening southerly flow ahead of an approaching cold front will prompt Tds to return to the mid and upper 60s...while PWAT values will surge to around 2 inches. This may sound like a broken record from last week...as this increasingly sub tropical environment will become ripe for afternoon convection. Forcing the increasing chance for showers and thunderstorms...some with drenching downpours and gusty winds...will be a pair of frontal boundaries. As is most often the case during the summer...the approaching cold front will be preceded by a pre-frontal sfc trough. This will help to initiate some thunderstorms over the Southern Tier and western Finger Lakes during the afternoon...then more widespread convection can be expected late in the day into the evening with the passage of the actual cold front. Forecast bulk shear of 40kts or so will increase the risk for organized convection that could produce gusty winds...particularly over southern areas. SPC highlights the most favored area for severe weather to be well to our southwest...in the vcnty of the Ohio valley. Temperatures on Wednesday will top out between 85 and 90...with the higher end of that range expected for the lake plains where heat index values will approach the mid 90s. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... A cold front will gradually drop across our region Wednesday night and Thursday morning, with showers and thunderstorms through the evening, then diminishing overnight as daytime instability decreases. Greater instability does not arrive until the evening hours maintaining thunderstorm chances and coverage area, of which some could still be producing heavy downpours within a humid atmosphere, and PWATs around 1.5 to 1.75 inches. The surface front parallel to the convergent flow aloft could allow for training cells, especially across WNY. This front and deeper moisture drops to near the state line Thursday. A few showers or thunderstorms near the state line, otherwise much of the region will remain dry through the evening hours. Winds Thursday night will be light, generally from the northwest to west. && .LONG TERM /FRIDAY THROUGH MONDAY/... A mid level shortwave trough over the Midwest Friday and surface low, will track across the Great Lakes and to southern Quebec through Saturday night. A frontal boundary to our south will lift back northward as a warm front, with showers and thunderstorms forming within an increasing humid atmosphere ahead of the front. Greatest coverage to convection will be Friday night and Saturday, with the passing of the warm front, low level convergence on the nose of a 35 to 40 knot LLJ that will reside under divergent flow aloft, and broad scale lift ahead of the shortwave. Strongest storms will likely be across eastern areas Saturday where lingering MUCAPE values of 1000 J/KG and 0-6 km bulk shear values near 50 kts ahead of a cold front could boost thunderstorms. High pressure will settle across our region from the Ohio Valley Sunday and Sunday night. From this direction, though humidity will lower, it will not be that crisp autumn like feel to the air. Falling heights, and southerly return flow Monday will give potential for more showers and thunderstorms moving back into our region. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... High pressure over the region early this morning will make its way off the East coast this afternoon and evening. This will support fair dry weather with wide open VFR conditions and light winds through the TAF period. Outlook... Wednesday...VFR, then MVFR with showers and thunderstorms late Wednesday afternoon and Wednesday night. Thursday...Mainly VFR with a low chance of a shower or thunderstorm across the western Southern Tier. Friday and Saturday... Mainly VFR with a chance of showers and thunderstorms. && .MARINE... High pressure exiting across New England will support light to gentle winds featuring a primarily easterly component throughout the Lower Great Lakes today...along with negligible waves. This will favor good to excellent conditons for recreational boating through the evening hours. Winds will veer to the south and freshen somewhat later tonight and Wednesday...as a cold front will approach the region. While fair weather will remain in place through at least midday Wednesday... there will be an increasing risk for thunderstorms Wednesday afternoon and evening. In the wake of the cold front...fair weather will return to the region later Wednesday night with subsiding southwest breezes. Looking ahead to the Fourth of July...gentle to moderate winds will be in place throughout the region. These winds will be from the southwest on Lake Erie and primarily from the west on Lake Ontario. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ SYNOPSIS...RSH NEAR TERM...RSH SHORT TERM...Thomas LONG TERM...Thomas AVIATION...RSH MARINE...RSH