^^RAH back to the doom and gloom for the 4th:
Thu/Thu night: The potential for both thunderstorms and high heat indices remain the biggest weather concerns for the 4th of July. PW will be anomalously high, nearing or perhaps exceeding the daily record, as the weak surface wind field along the Piedmont trough makes for stagnant air, contributing to the stifling heat. Thicknesses are likely to be 10-15 m above normal with deep mixing. While forecast soundings and the steering flow pattern suggest that there should be considerable mid and high cloudiness, a brief capping near 850 mb Thu morning may initially inhibit cu formation, leading to increased insolation. Highs should be in the low-mid 90s, and with expected dewpoints in the low-mid 70s, a heat index ranging from the upper 90s to lower 100s is reasonable. Those outdoors and not taking breaks in air conditioning will need to be mindful of threats posed by heat illnesses in such conditions. The very weak mid level flow featuring multiple hard-to-track perturbations within a very moist column should result in a high pop but with low timing and spatial predictability. Given the precip variation among large scale models, will cap thunderstorm pops at around 50% late in the day through evening (potentially interfering with holiday activities), with a tapering down to lower chance late overnight. I would not be at all surprised to see all models trending even wetter for the 4th in their later runs. And with weak steering, moderate CAPE, and high PW, heavy downpours could produce pockets of high, flooding totals.