Issued: 12am on Thursday, January 1st 1970
Technical Forecast Discussion
Short Term (Sunday 10/6 through Wednesday 10/9)
As of 00Z Monday, a positively tilted trough has been positioned over the Mid-west/Western Great Lakes region. The upstream flow of this mid-level trough is SW’ly to NE’ly situated over the aforementioned region with the main surface low well lifted north of Ontario, Canada. From this apparent low, a SE’ly extending cold front drapes through parts of the eastern Great Lakes while stretching SW’ly along the windward side of the Appalachian Mountains. An abundance of moisture and entirely saturated soundings will progressively lead to overcast and rainy conditions for the remainder of Sunday as this WNW’ly cold front approaches. Instability has been very low across the region with precipitation primarily being rain. In addition to the fairly saturated troposphere, PWAT values will continue to display high moisture content upwards of 1.8in ahead of this cold front. Therefore, with a SW’ly flow near the surface, training-type precipitation will be expected through Sunday night and into Monday morning offering modest rainfall accumulation. Model guidance has indicated rainfall accumulation upwards of 1.5-2.5in by early Monday afternoon. Local flooding may be of concern as conditions have previously been abnormally dry as of lately. This objectively slow-moving cold front will continue to propagate further southeast of the region with its projected passage around 06z-08z Monday. Despite the FROPA, the upstream flow and abundant low-level moisture is hesitant to evacuate, leaving an increase in precipitation and cloud cover extending through Monday afternoon. The timing of the passage, prominent N’ly CAA and overcast conditions will significantly reduce the high temperature for Monday. High pressure ~1027mb will soon fill in, but progressively lift NE’ly over Lake Erie 08z Tuesday introducing drier and calmer conditions for the remainder of the short term… Temperatures will near the average for Tuesday, but gradually warm into the mid-70s by mid-late week as upper level ridging and a veering southerly wind component takes shape.
Long Term (Thursday 10/10 through Saturday 10/12)
Higher surface pressure ~1024mb and upper ridging will continue to maintain dry, but warmer conditions for the beginning of this term. This ridging pattern and southerly surface winds will introduce more WAA, which will lead to above average temperatures into the mid-upper 70s for Thursday and Friday. Simultaneously, as upper ridging holds across the eastern U.S, a strong upper-level trough will greatly dig across the eastern Rockies by 00z Friday. This trough is expected to deepen and negatively tilt its axis over the Southwestern Midwest by 00z Saturday. Additionally, a strengthening surface low is currently projected for northern Minnesota by this time and extend a strong and well-defined cold front into the region. Future model guidance will better project the timing of this cold front as the current FROPA for SE Ohio is set for sometime Saturday evening. This strong system out of the upper Midwest will generate strong pressure and temperature gradients, which will likely introduce stronger surface winds and a cooler airmass late term/late weekend.
