Area Forecast Discussion National Weather Service Buffalo NY Tue Jul 14 2020
.SYNOPSIS... Weak high pressure will move across the region and will provide fair weather tonight and Wednesday before a weak trough brings showers and thunderstorms Thursday into Friday. Meanwhile, heat and humidity will build late in the week and during the weekend.
.NEAR TERM /THROUGH WEDNESDAY NIGHT/... Channelled vorticity to support scattered convection over North country through 23z...otherwise high pressure and dry weather tonight. Same area of high pressure to guarantee fair dry weather Wednesday and Wednesday night...warmer.
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... An upper level ridge will push east over New England Thursday, allowing a shortwave trough to approach our region. Meanwhile, at the surface a warm front will begin to cross the region Thursday which will increase the chances for showers and storms as well as advect warmer air into the region. Temperatures Thursday will bump up a few degrees more with highs projected range in the 80s, where the higher end of the spectrum will occur through the lower elevations.
Closely following the warm frontal passage, a cold front will sweep through the area late Thursday and Thursday night before stalling over the region Friday. Quite uncertain as to how far west the front will progress during the peak daytime instability hours. The combination of the upper level forcing from the shortwave and cold front will increase the threat for showers and storms across the region, however the better chances will occur along the frontal boundary. Narrowing the location of where these showers and storms will initiate directly correlates to the frontal position.
.LONG TERM /SATURDAY THROUGH TUESDAY/... In the wake of the cold frontal passage, upper level ridging will attempt to invade into the region for the weekend, lasting through the beginning of next week. In its attempt, the region will become oriented under the northern portions of the upper level ridge and have more of a zonal orientation. This pattern will allow for some possible weak upper level disturbances to ride through the westerlies, which will keep the region under chances for showers and storms throughout much of the weekend and into early next week. Nearing the end of the period, there is the potential for another passage of a cold front sometime early next week.
Aside from the shower and storm potential during this time, the other headline during this time is the return of the heat and humidity. High temperatures will rise up into the upper 80s and low 90s across the region throughout the period. However, these temperatures combined with dewpoint temperatures in the low 70s on Sunday and Monday will allow heat indices to reach well into the 90s.