Issued: 12am on Thursday, January 1st 1970
Technical Forecast Discussion
Short Term (Sunday 8/25 through Wednesday 8/28)
Fair conditions will remain in place, but progressively diminish as upper-level ridging lifts ENE of the region early into Monday. In conjunction, an upper level trough digs eastward through the upper Great Plains and sets up a meridional pattern for much of the Midwest. This synoptic setup will be highly influenced by a notable LLJ and affect the upper level low positioning itself over southcentral Canada. Widespread WAA, height falls, and some strong moisture advection will fuel the associated warm fronts ahead of the southerly extending cold front. With the initial warm sector approaching the region through Monday afternoon, cloud cover will begin to thicken and increase as low-level moisture gets filtered in. Thoroughly saturated profiles will lead to extensive cloudiness for this term in addition to slightly cooler highs nearing the 80-degree mark. Progressing into Tuesday, the aforementioned upper level trough axis will tilt very much negatively, but show evident signs of weakening. This heavily influenced LLJ will minimize the eastward progression of the low as filling seems fairly imminent over northeastern Minnesota into Tuesday evening. Despite this, the observed low will continue to drag its weak N-S extending cold front through the region by 08z-12z Wednesday. Lacking the instability and well-established upper forcing, any precipitation will be mostly limited to rain for Monday night through Wednesday. Some thunderstorm activity may arise within the precipitation just ahead and along the front itself. High moisture content with dewpoints eventually climbing in the upper 60s with PW values up to 2.0in may introduce some heavy rainfall at times. Precipitation chances and low-level cloud cover will progressively diminish throughout Wednesday morning with this frontal passage. Ever clearing conditions can be expected Wednesday night and into Thursday as weak high pressure and pronounced CAA settles in over central Appalachia.
Long Term (Thursday 8/29 through Saturday 8/31)
Drier and slightly cooler weather conditions will be expected throughout Thursday and into Friday as the weak high pressure lingers just SE of the area. This high of about 1020mb looks to eventually breakdown and push further east as the early part of the weekend persists. Yet another upper level trough shifts eastward along southeastern Canada into the end of this term. With weak zonal flow aloft and a weak jet, the strength and organization of this trough will be very much reduced in its effects. Currently with limited confidence, this upper disturbance tries to push a weak cold front through the region by late Saturday afternoon that will introduce a risk for more rain showers. More model runs will help determine whether this front can push through the region or end up stalling out along northern Ohio. Temperatures will continually remain fairly cooler than average with highs fluctuating in the upper 70s/ lower 80s for the remainder of the weekend and even through the next early work week.