Area Forecast Discussion
Issued by NWS Cleveland, OH

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KCLE 191030 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 630 AM EDT Tue Mar 19 2024 .SYNOPSIS... A weak ridge exits eastward before a cold front sweeps eastward through northern Ohio and northwest Pennsylvania this evening through the wee hours of Wednesday morning. Behind the front, a trough lingers over our region before a ridge builds from the northern Great Plains Wednesday night into Thursday. The ridge then exits eastward Thursday night through Friday as a low pressure system overspreads our region from the northern and central Great Plains. && .NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
6:30 AM EDT Update... Forecast remains valid per latest trends in obs and model guidance. No changes appeared necessary. Previous Discussion... W`erly to NW`erly flow aloft and embedded shortwave disturbances affect our region through Wednesday. At the surface, a weak ridge exits toward New England and vicinity before a cold front sweeps E`ward through our CWA this evening through the wee hours of Wednesday morning. Behind the front, a trough lingers over/near the eastern Great Lakes, including our CWA, before a ridge begins to build from the northern Great Plains by early evening. Intervals of sunshine and low-level WAA ahead of the cold front will allow this afternoon`s highs to reach the upper 30`s to lower 40`s in NW PA and the lower 40`s to near 50F in northern OH, with the warmest readings expected in our I-75 corridor counties. Diurnal convective mixing of the boundary layer tapping into stronger flow aloft will allow SW`erly surface winds to gust up to 30 to 45 mph late this morning through early evening. The strongest gusts are expected roughly along and west of I-71. Latest HREF runs indicate the chance of advisory-criteria gusts of at least 46 mph is 10% or less in our CWA. Low-level CAA behind the front will contribute to overnight lows reaching the upper 20`s to mid 30`s around daybreak Wednesday. Afternoon highs on Wednesday should reach only the lower to mid 30`s in NW PA and the mid 30`s to lower 40`s in northern OH as low-level CAA persists. Lake-effect snow showers persist amidst a sufficiently-cold/moist mean low-level flow over/downwind of ~7C Lake Erie. This LES will transition into lake-enhanced snow (LEnS) later this morning through afternoon as moist-isentropic ascent preceding an approaching shortwave trough axis generates snow-producing clouds farther aloft, leading to the seeder-feeder process. The LES/LEnS will continue to shift N`ward as the mean low-level flow backs from WNW`erly to SW`erly ahead of the aforementioned and prominent shortwave trough approaching from the western Great Lakes and vicinity. Accordingly, LES/LEnS should shift offshore NE OH/NW PA by late morning. The LES/LEnS will be steady at times courtesy of the seeder-feeder process and low- level convergence along bands` major axes allowing moderately- strong ascent to be maximized in a cloudy DGZ at least 0.5 km deep periodically. LES/LEnS, perhaps mixed with rain, is then expected to remain offshore our CWA through this afternoon as mean low-level flow remains SW`erly ahead of the shortwave trough. Once the shortwave trough axis crosses Lake Erie this evening and moves farther E`ward overnight tonight, lake-enhanced precip will shift back S`ward into the primary snowbelt of NE OH/NW PA and vicinity, and transition back to pure LES by daybreak Wednesday as lake-induced thermodynamics remain favorable, mean low-level flow cools while veering from SW`erly to W`erly, and the seeder-feeder process ceases as mid-level moisture plummets. Outside the lake-effect/enhanced precip, fair weather is expected in northern OH, including along the cold front as the front encounters a relatively-dry air mass. However, isolated snow/rain showers are possible in NW PA where model guidance continues to indicate the front should encounter greater low-level moisture. Additional snow accumulations through daybreak Wednesday are expected to be two inches or less. On Wednesday, the mean low-level flow of sufficiently-cold/moist air over/downwind of Lake Erie should veer from WNW`erly to NW`erly and allow LES showers to impact NW PA, NE OH, and portions of north-central OH. These LES showers may mix with a few raindrops during the afternoon, especially in northern OH. Precip should mainly be light, but steadier LES is possible in NW PA Wednesday afternoon/early evening when an upstream moisture connection to Lake St. Clair may target that area. Additional snow accumulations are forecast to be a coating to two inches. The greatest snow accumulations should be focused in the colder higher terrain of NW PA.
-- End Changed Discussion --
&& .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... With an upper trough still curling over the Northeast United States on Wednesday night into Thursday with northwest flow over the Great Lakes region, some lake effect snow showers will still be possible in Northeast Ohio and Northwest PA through the first part of Thursday. Snow accumulations seem limited with just scattered snow showers expected, but they will continue to keep a persistent little snow pack in some of the higher terrain of the NE OH and NW PA snow belt. The upper trough pulls away from the region on Thursday and high pressure will be aggressive to build into the forecast area on Thursday allowing for a largely dry forecast. With an origin from the northwest, temperatures on Thursday will be cold and generally remaining in the 30s across the area. Another upper trough of the northern stream jet will dip toward the area on Friday. This feature will pick up a shortwave moving through the southern stream over the Gulf Coast states. This combination should allow for a broader low pressure system to move through the eastern CONUS and bring some rain chances on Friday with some warmer temperatures toward the 40s. Depending on how much the northern flow can pick up this system, there could try to be enough cold air over the northern half of the area to allow for initial precipitation type on Friday to be some snow before transitioning all to rain. Impacts from any snow appear limited at this time. && .LONG TERM /SATURDAY THROUGH MONDAY/... Generally speaking, the weekend forecast appears uneventful at this time. The late week system should be exiting to the east on Saturday morning and some lake enhanced precipitation could remain into NW PA. However, high pressure seems aggressive to build into the region and have a largely dry forecast for Saturday and the daytime hours on Sunday. The next upper trough will enter the central CONUS on Sunday night into Monday and will support the next low pressure system that will target the forecast area for early next week. Have increasing PoPs Sunday night through Monday night with the highest later on Monday. Temperatures through the period should be fairly seasonable for the 4th weekend of March. && .AVIATION /12Z Tuesday THROUGH Saturday/...
-- Changed Discussion --
At the surface, a weak ridge exits E`ward before a cold front sweeps E`ward through northern OH and NW PA between ~22Z/Tues and ~05Z/Wed. Behind the front, a trough lingers over our region through 12Z/Wed. W`erly to WNW`erly regional surface winds back to SW`erly behind the surface ridge axis and remain around 10-15 knots with gusts up to 20-25 knots at times. After 14Z/Tues, SW`erly surface winds are expected to increase to 15-25 knots and gust up to 25-35 knots through ~22Z/Tues. Once the cold front passes, regional surface winds veer to W`erly and ease to around 10-15 knots. These post-front winds should gust up to 20-25 knots in the immediate lee of Lake Erie, including at KERI. Widespread low clouds with ceilings near 3kft to 5kft AGL continue to exit E`ward with the passage of the aforementioned surface ridge axis and should exit the rest of our region by 14Z/Tues. Lingering lake-effect snow showers and associated VFR/MVFR low-level ceilings streaming generally E`ward from Lake Erie continue to shift gradually N`ward and should be offshore northern OH and NW PA by ~13Z/Tues as mean low-level flow backs from W`erly to SW`erly. However, behind the cold front, lake-effect snow showers and associated VFR/MVFR low- level ceilings should redevelop and stream generally E`ward across far-NE OH and NW PA between ~06Z and ~12Z/Wed. As for the cold front, limited low-level moisture should permit a dry front passage in northern OH. However, isolated snow showers, perhaps mixed with rain, may accompany the front in NW PA. Visibility is expected to vary between VFR and MVFR in precip. Outlook...Non-VFR expected with periods of snow and/or rain on Wednesday through Saturday.
-- End Changed Discussion --
&& .MARINE... A trough remains across the eastern Great Lakes and brisk westerly winds remain across the entire basin, allowing for a Small Craft Advisory to continue across the nearshore zones. A low pressure system north of Lake Superior will dive southeast across the Great Lakes today and back winds to the southwest. Winds will lessen a bit tonight and there could be a brief window without the need for a Small Craft headline and will maintain the 00z end time tonight. The low will start to move east through Canada and extend a cold front across the lake on Wednesday to allow for elevated northwest flow to return. An extended or new Small Craft Advisory will be needed for Wednesday into Thursday with high winds and waves. High pressure will build into the region for Thursday to lighten winds and allow for more calm weather to return to the lake. A low pressure system will move through the region on Friday and some easterlies may be expected. The system will depart for the weekend and northwest flow will return and there could be room for another Small Craft headline to be needed. Overall, it is certainly a more active pattern typical of the winter more than the spring. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. NY...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for LEZ142>149. && $$ SYNOPSIS...Jaszka NEAR TERM...Jaszka SHORT TERM...Sefcovic LONG TERM...Sefcovic AVIATION...Jaszka MARINE...Sefcovic

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.