Issued: 4pm on Friday, August 4th 2023
Technical Forecast Discussion
Short-term (Friday 8/4/2023 through Sunday 8/6/2023):
A weak cold front that is becoming more stationary is currently moving through the region, but thanks to drier air, the system is not expected to bring much precipitation at this time. Upper-level ridging associated with NVA is going to keep things nice and quiet for us through the short-term period. Towards the end of the short term, more PVA will push into the region associated with a positively tilted upper-level trough that will gain a more negative tilt, indicating a stronger system. As this trough gains a negative tilt, the surface low is also expected to begin to occlude as it nears the end of its lifecycle. Ahead of this system, a push of moisture with southwesterly flow downstream of the trough will be in place to allow for the severe weather that is anticipated.
Long-term (Monday 8/7/2023 through Thursday 8/10/2023):
The long-term forecast period is expected to begin much more active than the weekend. As the upper-level trough becomes negatively tilted, enhanced by a wave of PVA entering the region. CAPE values from medium-range model guidance are expected to be around 2,000 J/kg and will possibly exceed that as better short-term guidance rolls in. Moderately steep lapse rates will contribute to enhanced cooling with height indicating threats for damaging winds as well as a potential threat for small hail. Thunderstorms will likely begin to fire along a warm front with warm air advection into the region, bringing in plenty of moisture and fueling thunderstorms for the day. The warm front will be followed by a relatively strong cold front, which is where the main threat of severe weather will materialize. Medium- to long-range models also suggest a small tornado threat for the day with backed southwesterly winds at the surface, veering with height, particularly concerning the first 3km. Model soundings show curved hodographs in the first 3km with some length to them. However, the likely linear storm mode should keep the threat of tornadoes to just an isolated spin-up or two, and short-term models will give us a better idea of the magnitude of the tornado threat.
For the rest of the long term, more zonal flow and upper-level ridging will dominate over the region as surface high-pressure moves in, meaning quiet weather at least through Wednesday. Thursday, another upper-level disturbance is expected to bring a cold front through the region sometime Thursday into Friday. Precipitation is expected from this system right now. Thankfully, at this time, the next cold front does not appear to bring much, if any, severe potential as the cold air advection is not as strong as Monday’s system is expected to be.
Synopsis:
Friday-Sunday Morning: Mostly sunny with dry conditions.
Sunday-Wednesday: Showers starting ahead of the warm front, then severe weather possible on Sunday and Monday with an incoming cold front.
Wednesday-Friday: Mostly pleasant conditions Wednesday, then more showers and thunderstorms possible on Thursday with another incoming cold front.
