National Weather Service
Area Forecast Discussion

335 PM EDT Tue Jul 16 2019
The remnants of Barry will move through the Ohio Valley tonight and Wednesday, bringing numerous showers and a few thunderstorms. It will remain humid through the entire week with hot conditions expected Thursday through the weekend as a large dome of heat develops over much of the eastern half of the United States. Outside of rain chances tonight and Wednesday, much of the rest of the week and into the first part of the weekend will remain dry.

Numerous showers and embedded thunderstorms will continue to move into the forecast area from the west this evening as the remnants of Barry move toward the region. High pwats will bring the threat for locally heavy rainfall, although there should be some appreciable storm motion. Concern will be where storms line up over the same region depending on the mean steering flow which may result in localized flooding/flash flooding. This is covered in the latest HWO. In addition, any severe threat should be relegated to an isolated strong or severe wind gust due to pcpn loading, which will be highest this afternoon and this evening when instability will be at its greatest (allowing cores to reach there peak height). This is also covered in the HWO as well. The hail threat is minimal due to high freezing level, skinny-like CAPEs, and relatively poor mid level lapse rates. Have gone with coverage/likely PoPs for tonight as low level moisture transport and ascent with the approaching disturbance work in tandem. Overall thunder threat should decrease overnight as instability diminishes, but locally heavy rainfall will remain. It will be warm and muggy with lows in the lower 70s.

The remnants of Barry will move east across the Ohio Valley on Wednesday. Numerous showers and a few thunderstorms will be ongoing during the morning. By afternoon, pcpn coverage will begin to shift to the east as the region starts to become more in the wake of the system. Again, high pwats (2 inches plus), WCDs, skinny CAPEs, and high freezing levels will make collision/coalescence favorable with warm core centroids. Event so, overall rainfall amounts on a larger scale should be held in check, with only isolated threats for flooding/flash flooding. This will continued to be mentioned in the HWO. It will be humid, but temperatures will probably be the coolest of the week and upcoming weekend due to clouds and pcpn. Highs will warm into the lower to mid 80s.

For Wednesday night, some weak mid level ridging will try to build into our area. This should allow for a rapid decrease in pcpn coverage/threat with skies becoming partly cloudy. It will be warm and muggy with lows in the lower 70s.

The majority of the moisture from what is left of Barry will be east of the region by Thursday morning. However there is a little lingering instability on Thursday to keep a 20 PoP in the forecast for about the southern 2/3 of the fa. Warm and humid conditions will affect the region with highs in the lower 90s and dewpoints in the 70s. This would push the heat index over 100 degrees.

Thursday night into Friday, the H5 ridge starts to build north. This will allow the heat and humidity to build and peak Friday into Saturday. Highs are forecast to push into the mid 90s and dewpoints into the mid 70s, producing heat indices around 105. Will hold off on issuing an Excessive Heat Watch, but will keep the mention in the HWO.

The heat and humidity will begin to lower Sunday as the H5 ridge begins to break down as a backdoor cold front drops into the region. Scattered thunderstorms are forecast with the front in the area.

The front should be south of the region Monday, but lingering lift across the region could produce some scattered convection. Highs on Monday will be down into the upper 80s due to the cloud cover and convection.

By Tuesday, high pressure centered over the Great Plains will be bringing less humid air into the region. Highs will be in the lower to mid 80s.

The remnants of Barry over the middle Mississippi River Valley will move east into the Ohio Valley tonight. As this occurs, low level moisture transport/ascent will bring numerous showers and embedded thunderstorms early on, with mainly numerous showers and a few thunderstorms late as the overall instability wanes. The very moist airmass will be capable of producing locally heavy rainfall where MVFR/IFR conditions may occur, with lower visibilities of LIFR possible in the heavier downpours. Can not get too specific with these low conditions just yet at the terminals, but have allowed for some MVFR conditions with either showers or storms to occur late this afternoon into this evening. For the overnight, ceilings will lower as the airmass cools and saturates with IFR ceilings expected toward 12Z Wednesday.

On Wednesday, the remnants of Barry will continue to move east. Showers and embedded thunderstorms will slowly move east as well. We should see a decreasing trend in shower/storm coverage from west to east between 15Z Wednesday and 00Z Thursday as the region eventually finds itself in the wake of this system. IFR ceilings and MVFR visibilities will gradually improve through the day with VFR conditions becoming predominate between 21Z Wednesday and 00Z Thursday.


Thunderstorms possible Sunday.

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