Issued: 12am on Thursday, January 1st 1970
Technical Forecast Discussion
Short term (Sunday 7/29 through Tuesday 7/31)
A upper level trough will be the main upper level pattern over the continental US heading into the week. As high pressure moves farther east tonight, the trough will push a low pressure system into the region late tonight that will bring an influx of moisture. The timing of the system will make precipitation unlikely as convection will be at its lowest and moisture will be too late to receive any lift from diurnal heating. This influx of moisture will help produce cloud cover in the later evening tonight. On Monday, a shortwave trough becomes more pronounced on models and looks to become to dominant feature on Monday. The low pressure system will move in closer from the southeast. Severe weather looks unlikely, but jet streaks maxing at 100 knots and shearing will be present, so if moisture remains ample, downpours will be possible. Precipitation will last overnight due to humidity trapped in cloud cover. A small break in the clouds on Tuesday will lead to a short break in precipitation. A larger jet streak will be over western Ohio on Tuesday. Models put peak winds anywhere from 100 to 120 knots. This will help bring the maturing low pressure system northward. The warm frontal boundary is expected to pass over the area on Tuesday. Cloud cover and precipitation from Tuesday morning will limit further atmospheric destabilization and keeps CAPE values low. Shearing will be spotty despite the presence of the jet streak, so severe risk will be similar to Monday with downpour a little more isolated.
Long term (Wednesday 8/1 to Saturday 8/4)
Troughing becomes apparent in the upper levels again on Wednesday. The cold front will be slow to enter the region as jet streak become nearly vertical, slowing horizontal progress of the system. Storm activity will be driven mostly by diurnal heating. Shearing will be available, but moisture will leave by late Wednesday, so storms and showers will die off around mid-evening. Stray high pressure moves into the region on Thursday that will give the area a break from storms temporarily. Clouds will slowly decrease as the day progresses. On Friday, small portion of moisture will remain in the area. Models show a small embedded trough along with this moisture. Currently these are the only two indications of an unstable environment, so a small chance for storms will remain for Friday afternoon. Upper level ridging begins to take over on Saturday. A trough in the mid levels will remain, but the ridging coupled with high pressure in the Virginias should be enough to keep precipitation at bay.
The next technical discussion will be on Wednesday 8/1