National Weather Service
Area Forecast Discussion

1035 AM EDT Sun May 19 2019
SYNOPSIS
A strong low pressure system will bring gusty winds and the chance for severe weather today. A cold front will push east across the area tonight. Cooler and drier air will work into the region for Monday and Tuesday as high pressure influence`s the region`s weather before warmer air and precipitation chances return to the forecast for Wednesday.



NEAR TERM
THROUGH TONIGHT
Embedded short wave energy rotating northeast around an upper level low over the western Great Lakes will induce a low level jet which will move northeast across our area this afternoon. Pcpn associated with this low level jet is currently across western Kentucky, southeast Illinois, and southwest Indiana.

With a fairly strong wind regime in the low levels associated with the low level jet, we still run the risk of wind advisory criteria type wind gusts, around 40 knots, across much of the region. However, clouds and light pcpn now encroaching our western zones may limited heating and deeper mixing. Best chance will likely occur near the I-71 corridor where more heating will occur before pcpn moves in later this afternoon. For now, will leave the Wind Advisory as is as it does not start until 11 am, and will reevaluate as the afternoon wears on. Will also keep the SPS out for sub-advisory wind gusts across the far southeast.

Attention then turns to severe weather potential. It is all about the instability. Models suggest that as clouds thicken and pcpn moves in, instability may be limited to MLCAPES of 500 to less than a 1000 J/kg. This may limit severe potential as there may be more embedded storms than likely storms. There is still cause for concern due to the very strong low level wind flow regime which would mean it will not take much to get 50 knot gusts to the surface. Feel that if instability remains limited, there should not be a big large hail threat. As for an isolated tornado, can not rule it out with strong speed shear, although directional shear is lacking.

Temperatures during the day today will be warmer across eastern portions of the forecast area where it will take longer for the precipitation to work into the region. High temperatures will range from the middle 70s across western portions of the region to the middle 80s across the east.

Going into the overnight hours tonight, the severe threat will diminish. The wind gusts will decrease, however expect some wind gusts to continue through this time. Went close to the blend for temperatures and made only minor changes.



SHORT TERM
MONDAY
Much cooler conditions will be present for monday with high temperatures in the 60s and 70s. With CAA expect cu field to develop. Cannot rule out a few sprinkles, but decided to leave the forecast dry for now. Although winds will gust at times on Monday, expect wind gusts to be lower than Sunday. Wind gusts in the 20 to 30 mph range will be possible on Monday, especially across northern portions of the region near and north of Interstate 70.



LONG TERM
MONDAY NIGHT THROUGH SATURDAY
High pressure extending across the area at the beginning of the period will keep one more day of seasonal temperatures. A warm front will lift into the area late Tuesday night into Wednesday morning as a short wave moves up the Ohio Valley. This will bring a chance of showers and embedded thunderstorms.

In the wake of this system, upper ridging will develop north into the region. This will bring a quick warm up as well as an increase in dew points. Daytime temperatures will be well into the 80s, with a few spots likely to reach 90, on Thursday and Friday with lows only dropping back into the mid to upper 60s. A weak boundary may drop into the region Thursday into Thursday night which could be a focus for some convection.

00Z guidance suite is showing some discrepancies on strength of a short wave riding over the top of the ridge heading into the weekend. This affects the timing of a front dropping south out of the Great Lakes. Have leaned towards a slower speed which would bring a greater chance of storms to northern counties on Saturday.



AVIATION
15Z SUNDAY THROUGH THURSDAY
Dry conditions will start out the TAF period. There will be some mid and high clouds around this morning. LLWS will also be possible this morning at the start of the TAF period.

Winds will increase through the morning hours. Wind gusts of 30 to 40 knots are expected today. Showers and some thunderstorms as well will work into the region this afternoon and into the evening hours.

Precipitation will begin to taper off at the end of the TAF period and winds will begin to decrease. Some MVFR clouds will be possible across portions of the area towards the end of the TAF period.

Winds will start to pick up a little again during the day on Monday and have some wind gusts around 20 knots at the longer KCVG TAF.



OUTLOOK

MVFR cigs possible Monday morning. Thunderstorms possible Wednesday and Thursday.