MikeB_01

Mesoscale Precipitation Discussion 0753 NWS Weather Prediction Center College Park MD 315 PM EDT Tue Aug 13 2019 Areas affected...portions of the upper OH Valley into southwestern PA/western MD Panhandle Concerning...Heavy rainfall...Flash flooding possible Valid 131914Z - 140015Z Summary...Brief training of showers and thunderstorms could lead to flash flooding across portions of the upper OH Valley into southwestern PA/western MD Panhandle through 00Z. Rainfall rates of 1-2 in/hr will allow for localized 2-3 inch totals across the region. Discussion...Regional radar imagery through 1845Z showed a small cluster of thunderstorms expanding across eastern OH into far western PA. The convection was located to the south of an 850 mb low, analyzed over central Lake Erie via regional VAD wind plots with 20-30 kt of westerly flow from KILN to KPBZ. Breaks in cloud cover over the upper OH Valley has allowed MLCAPE to increase into the 500-1000 J/kg range, via 18Z SPC mesoanalysis estimates, over east-central OH, while values fall off to less than 500 J/kg in western PA to the north of a warm front. Further increases in MLCAPE are anticipated through the remainder of the afternoon, especially over southeastern OH into northern WV where reduced cloud cover will allow surface temperatures to climb another few degrees. With precipitable water values of 1.7 to 2.0 inches and the expected instability, rainfall rates of 1-2 in/hr seem likely. Winds, generally from the west in the LFC-EL layer, are forecast to average 20-30 kt according to recent runs of the RAP through 00Z. Given 850 mb winds of similar magnitude and direction, periods of training convection will be possible later this afternoon into the early evening hours. An eventual clustering and propagation of storms toward the south is expected as thunderstorm coverage increases. Therefore, flash flooding appears to be a threat with 2-3 inch rainfall totals and rates of 1-2 in/hr. These values are near or in excess of local Flash Flood Guidance values. Otto

Atmosphere is looking loaded for tomorrow afternoon. Even though the sounding is saying "Tor" I am not sure i buy that. Not enough directional shear for it imo. Damaging straight line winds look more likely

Noticed they uped it to Enhanced at the for the latest outlook. Saturday is looking juiced up and ready to go as well.

Anyone else already tired of Jeff V on twitter? All I hear about it "No hype" / "No Fearcasting". Great, that is really appreciated. Some stations are notorious for fearcasting, I get it. But come one, he didn't even start talking about accumulating snow until Friday night. He was still saying "snow shower".

F Boston and their 12" snow storm. They complained all year and it looks like they will be rewarded with it. They got a decent hit today and another one coming tomorrow

How bad has the NAM been at temp profiling this winter? 12Z nam still had freezing rain at the onset of the precip tonight. My house in already at 33°. Well before any precip makes it to the area.

Does every system have to cut through Ohio? Like watching a bunch of bowling balls roll through

F weather. .

I remember this storm. Fortunately, I go much higher numbers than this. But i know some people in our thread got 2ft+

Unfortunately, I fall into both of those categories...

19 in report outside of boston. The rich get richer..

Feast your eyes on the South Carolina snow totals .

Can see the snow on the ground in southern Georgia. Crazy

How about 4 inches in northern Florida. You have got to be kidding me. .

Welcome to the climatology. We have easily the most mundane weather in the country. At least San Diego, though quiet, is beautiful. Pittsburgh is boring and grey .