Area Forecast Discussion
Issued by NWS Cleveland, OH

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000 FXUS61 KCLE 260510 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 110 AM EDT Wed Jul 26 2017 .SYNOPSIS... High pressure over Lake Erie will move east tonight and off the East Coast Wednesday afternoon. A cold front will push southeast through the region late Thursday as low pressure tracks along it to our south. Another area of high pressure will spread southeast into the area Friday and linger into weekend. && .NEAR TERM /THROUGH TODAY/... Only made minor changes to the temperatures to reflect current trends. Previous discussion... Fair weather is expected through Wednesday as high pressure over the region slowly shifts east off the East coast Wednesday afternoon. Mostly clear skies are expected tonight with some patchy fog possible in river valleys. Lower dewpoints will allow temperatures to range from near 60 at the lakeshore to the lower to mid 50s inland. No changes to tonight with this early evening update. Mostly clear skies are expected Wednesday as warm advection develops. There will be some increase in high and mid clouds in the afternoon from convection to the west. 850 mb temperatures will warm about 6-8C on Wednesday. Raised afternoon high temperatures on Wednesday slightly to reflect the strong warming aloft. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... The ridge will break down Wednesday night with cloud cover increasing from the west. Convection is expected to develop upstream across Iowa/Illinois Wednesday night and will have an impact on the weather for Thursday. The most likely track for this convection will be to the southeast along the better instability gradient. Given this expectation will keep the forecast dry until late Wednesday night with rain arriving from the west on Thursday. Nudged this back just a couple more hours with this update. The 12Z GFS/Canadian seem to offer a better depiction of this while the NAM/ECMWF are more aggressive with brining the stronger convection east into our area. Will continue with showers and thunderstorms on Thursday but expect the more intense convection to be focused south of the forecast area. This aligns well with the SPC Day 3 outlook which keeps the Slight Risk south of the forecast area. Tapered pops down slightly in the northeast with concerns that the moisture transport may be disrupted enough that a lower pop is appropriate. Also lowered highs a little in the south on Thursday given the coverage of showers and clouds. Adjustments will likely still be needed based on how thunderstorms upstream unfold. Low pressure will move through the Ohio Valley early Friday ahead of an upper trough dropping through the Great Lakes region. A chance of showers and thunderstorms will linger on Friday, especially in the east ahead of the trough during the afternoon. Will hold onto chance pops but they may need to be raised. Temperatures will trend cooler with northerly winds increasing on the back side of the system and highs generally in the low to mid 70s. High pressure and drier air will arrive by Saturday as high pressure builds over the central Great Lakes. More sun on Saturday will allow highs to recover several degrees. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Quiet and cool weather is expected during the period as high pressure slowly builds over the region from the north. The models begin to diverge toward the end of the period with the GFS trying to bring a weak cold front across the region on Tuesday. The ECMWF dissipates this front before it reaches the area and keeps the local area dry on Tuesday. That seems to be the preferred scenario and will keep things dry. High temps will be a couple degrees below normal. && .AVIATION /06Z Wednesday THROUGH Sunday/... Skies were clear across the region as of 05z. Expect this trend to continue until some patchy MVFR fog develops at inland TAF sites around sunrise. At this point will go with 4-5 mile visibilities and adjust if needed. Other than a few cumulus across inland locations this afternoon there will e a gradually increase in high level cloud cover. Winds will be light and variable into the morning then become southerly for inland locations. Speeds this afternoon will be under 6 knots. The exception will be along the lakeshore with an onshore west to northwest wind developing by early afternoon. This will only impact KERI and KCLE TAF sites. Speeds may touch 10 knots for a few hours during the afternoon. OUTLOOK...Non-VFR in thunderstorms that develop near and ahead of a cold front Thursday into Thursday night. Non-VFR due to low clouds through Friday and possibly into Saturday. && .MARINE... Easterly flow on Lake Erie will increase to 10-15 knots tonight as high pressure shifts from the central Great Lakes to New England. Winds will shift around to the south on Wednesday but lake breezes will develop on the east half of the lake Wednesday afternoon. Low pressure will move through the Ohio Valley late Thursday pulling a cold front south across Lake Erie. Northerly winds will increase behind the front Thursday night through Friday Night and Small Craft Advisories will likely be needed. Winds expected to be at least 15- 20 knots but could exceed 25 knots depending on the track of the system. Winds and waves expected to decrease through the day on Saturday as this system pulls away to the east. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...LaPlante NEAR TERM...Mullen/Oudeman SHORT TERM...Oudeman/KEC LONG TERM...Kubina AVIATION...Mullen MARINE...KEC is the U.S. government's official web portal to all federal, state and local government web resources and services.