... High pressure slides east tonight with our next weather disturbance arriving on late Friday. Unsettled weather is then expected for the upcoming weekend.
NEAR TERM /THROUGH FRIDAY/... As of 620 PM Thursday...
Minor changes made to hourly temperatures and dewpoints. Rest of forecast remains on track.
As of 137 PM Thursday...
High level cirrus is spreading across the area this afternoon well ahead of an elongated positively-tilted upper level trough with a closed low positioned across the Ozarks region of MO/OK/AR. As this feature shifts eastward across the mid Mississippi Valley tonight into Friday, it will gradually become more neutrally tilted with time and a surface low across the northern Gulf Coast will track to the northeast. This low pressure system is expected to move across the Tennessee Valley Friday afternoon and across the Carolinas Friday evening, deepening as it does so. Meanwhile for our area, increasing forcing for ascent with height falls aloft and moisture advection into the area will support an increase in precipitation coverage from south to north on Friday.
As precipitation initially arrives Friday morning, low levels will still be rather dry but a moistening trend is expected as a 35-40 kt LLJ spreads into the area. As a result, rain chances will increase by Friday afternoon and evening across the region with widespread rain showers developing during this time. In addition, despite abundant cloud cover and the associated rain across the area, the southwest flow in place ahead of the approaching upper trough/low should allow for near-normal highs on Friday afternoon. Otherwise, precipitation is expected to continue beyond this period as this system continues to strengthen to the southeast of our area.
SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... As of 142 PM Thursday...
A low pressure located to our south at the beginning of the period will deepen as it pushes off the east coast by Saturday morning. Behind the system, a cold front should push southeast across the area Friday night ushering in a colder airmass.
The precipitation should mix with and change over to snow across much of southeast OH and northeast KY as well as the higher e elevations of the mountains with a wintry mix across the remainder of the region late Friday night into Saturday. On Saturday, precipitation should revert to rain over much the lowlands while ending ending from the west. However, northwest flow will result in snow chances continuing in the mountains. A few inches of snow will be possible across the higher elevations.
Precipitation should come to an end Saturday evening as surface high pressure builds in.
Below normal temperatures are expected through the period with daytime readings in the lower 30s across the higher elevations with upper 30s to lower 40s elsewhere on Saturday. Daytime temperatures on Sunday should be a few degrees colder.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... As of 1145 AM Thursday...
While the timing is different, models continue to show several strong shortwaves digging southeast with a closed low developing and pushing east of the region Monday night. The ECMWF is a little faster and has the low pushing across southern PA and northern WV Monday afternoon. In contrast, the GFS is slower with the actual upper low passing by to our south.
At the surface, cold dry high pressure should dominate by late in the period.
While the long range models indicate clouds with this setup, there is not much confidence on any actual precipitation will occur. So the mention of precipitation has been kept out of the forecast at this time.
As the upper feature pushes east, northwest flow should develop with more sunshine during the day.
Daytime temperatures should be well below normal on Sunday and Monday with normal reading returning by Wednesday.