Forecast Discussion
Summary
SYNOPSIS
... An upper level low will persist over the New England states through the end of the week keeping our temperatures below normal. Another front may bring showers to the area midweek.
NEAR TERM /THROUGH TUESDAY/... As of 829 PM EDT Monday...
Afternoon convection will diminish quickly with the loss of solar heating. Haze from the Canadian wildfires may drift into our region tonight and may become thicker toward Tuesday morning as a low level inversion traps the smokey air near the surface. Adjusted temperatures for this evening into tonight utilizing the latest surface obs,their trends and blended in the NBM. Low temperatures will range from the mid 40s in the deeper mountain valleys to the mid 50s in the Piedmont.
Previous discussion: As of 509 PM EDT Monday...
Made some minor adjustments to temperatures for this evening into tonight. Adjusted cloud cover this afternoon into tonight shaping towards satellite trends. Will hold on to the light pops for convection in the southwest portion of the forecast area. Looks like to best instability is to our south and west. More changes later tonight.
Previous Discussion: As of 110 PM EDT Monday...
Weather will be mainly dry this period...
Mesoanalysis early this afternoon showed low pressure over far southwest VA with frontal boundary extending west along the TN/KY border. Latest trends in satellite/model and mesoanalysis indicates that thunderstorm development expect to be along/south of this boundary after 2pm, but moreso in the 3-9pm time frame. Models do vary as to an eastward threat with a couple having storms firing toward 7pm in southside VA and moving southeast into the NC piedmont.
Best instability shifting southward so cut back on the severe storm risk to mainly south of US 421 in NC.
Any shower/storms fade by late evening with mostly clear skies. Will have to see where it rains to add any fog development but most likely will have fog in the NC mountains/foothills Tuesday morning.
Tuesday should be dry, though watching another backdoor front track toward the Shenandoah Valley and central Appalachians toward dusk which may bring an isolated shower/storm to the Greenbrier Valley. Otherwise mostly sunny and warm with highs in the mid to upper 70s west to mid 80s east.
Confidence in the near term is high, except moderate on strong storm threat.
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 215 PM EDT Monday...
Showers and storms possible Wednesday with front then mainly dry and cool for Thursday...
The persistent upper closed low centered near New England will continue to have various shortwaves rotate along the southwestern extent into the region. The next main wave and translated sfc front is progged to push southward across the area for Wednesday into Wednesday night and allow for some scattered showers. There is limited forecast CAPE with this feature but enough to carry a slight thunder mention mainly for the southern half of the CWA. Not expecting much QPF with it either as most locations may just see a tenth to quarter of an inch. Guidance looks to keep the main moisture axis and front south of the CWA with now a drier solution for Thursday so have trended pops lower with only a slight chance of convection in the far SW. The NW flow and digging trough will advect unseasonably cool air into the area and Thursday morning looks to be quite chilly with mainly 40s in the mountains and low to mid 50s in the Piedmont.
Forecast confidence is medium to high.
LONG TERM /FRIDAY THROUGH MONDAY/... As of 215 PM EDT Monday...
Cool Friday in Saturday morning. Dry conditions until Sunday with next approaching system...
Continued cool and dry airmass under the NW flow aloft on western side of large upper low will round out the work week and start to the weekend. Abnormally low temps expected both Friday and Saturday mornings with 40s and 50s (Friday AM being a bit cooler than Saturday AM). We should start to rebound with warming temps during the day Saturday as flow finally shifts more zonal and the low level fetch swings to have a southerly component. This is all in advance of the next main influencing system as a piece of upper energy ejects southward across the Midwest and Ohio Valley for Sunday. With an increased moisture field east of the amplifying trough have increasing chance pops for showers and possible thunderstorms. We may see another closed low setting up shop over the area into early next week but we have plenty of time to see if this gets any run-to- run consistency or more consensus.
Forecast confidence is medium for Sunday and beyond.