493 FXUS61 KCLE 022008 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 408 PM EDT Sat Nov 2 2019 .SYNOPSIS... An upper level trough will persist through the week. Several pieces of low pressure will pass through this flow. The first arriving Monday and another Wednesday night. && .NEAR TERM /THROUGH SUNDAY NIGHT/... Leading area of sprinkles/very light showers is moving across the east with maybe a hundredth of an inch. Better forcing arrives this afternoon and will move eastward across the region into the evening. The 5H/7H upper level trough will cross the region this evening with the colder air spilling in behind it. So any of the precipitation over the lake should be pushed onshore across NE OH and NW PA through the evening. There is a chance of some thunder over the lake with a few of them brushing the lakeshore, especially near Erie. Believe most of the precipitation will remain liquid through the evening. However as we approach midnight expect to see the rain change to snow over the higher terrain. Models are hinting at the best accumulations occurring from around 08Z through 15Z, mainly across the higher terrain of inland NW PA. The higher terrain over NW Ohio could see a few locations that get over 4 inches. Will make no changes to the current headlines. Maximum amounts in NW PA could be around 6 inches near a line from Conneautville to Wattsburg. Temperatures will dip into the 30s at most locations. The only exception will be along the immediate lakeshore from Cleveland to Erie where lows around 40 may occur. The lake effect snow will slowly decrease in coverage and intensity through the day as the bands of snow shift up the lakeshore toward western NY. Current thinking ends the snow completely by late afternoon/early evening. Any additional accumulations should occur Sunday morning. Highs on Sunday will range from the mid 30s under the heavier snow to the mid 40s across the western half of the CWA. High pressure will be enough to keep the area dry for the first half of Sunday night. However the next piece of jet energy will move into the central Great Lakes overnight. Cant completely rule out some light rain across NW OH by sunrise. Lows Sunday night will range from the upper 20s east to the upper 30s across NW OH. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... Cyclonic flow aloft associated with a broad longwave trough affects our CWA during this period. In addition, embedded shortwave disturbances traverse our region. At the surface, high pressure exits to the east on Monday and a cold front begins crossing the western-third of our forecast area from west to east by Monday evening. Isentropic lift ahead of the front should contribute to isolated to scattered rain shower development. In addition, rain showers are possible along the cold front itself, while sufficiently-cold air ahead of the front should allow lake enhanced rain showers to occur over and northeast of Lake Erie. The eastward-advancing cold front should exit the rest of our CWA by daybreak Tuesday, with additional isolated to scattered rain showers along and ahead of this front. Again, these rain showers may be enhanced over the relatively-warm waters of Lake Erie. Behind the front, surface high pressure builds from the west for the rest of Tuesday morning through evening. In addition, behind the cold front, lake enhanced rain showers should transition to pure lake effect showers and settle southward to our snowbelt counties in northeast OH and northwest PA as the low-level flow of cold air veers from southwesterly to westerly. These lake effect rain showers should change to wet snow inland from Lake Erie Tuesday evening as the airmass cools. On Wednesday, any lingering lake effect rain and/or snow showers over our snowbelt counties should end by daybreak as surface high pressure crests over the region. Minor snow accumulations may occur, especially inland from Lake Erie and in the higher terrain. Scattered rain showers are then possible Wednesday afternoon and early evening as the next eastward-moving cold front begins to approach. Highs in the upper 40's to mid 50's Monday afternoon will be followed by low temperatures in the upper 30's to lower 40's Monday night. On Tuesday, afternoon highs should reach the mid 40's to near 50 degrees. After low temperatures mainly in the lower to mid 30's Tuesday night, Wednesday afternoon's high temperatures are forecast to reach the upper 40's to lower 50's. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... The broad longwave trough and associated cyclonic flow aloft continue affecting our region. A prominent shortwave disturbance embedded in the longwave trough may cross our region from west to east late Thursday into Friday. There is still rather large uncertainty regarding the evolution of the surface weather pattern. The general consensus of forecast model guidance is for a surface cold front to sweep east through the CWA Wednesday night and be followed by a rather cold and extensive surface high pressure ridge Thursday through Saturday. Rain and/or snow showers should accompany Wednesday night's cold frontal passage and may also accompany the passage of the aforementioned shortwave disturbance late Thursday into Friday. In addition, multiple models continue to suggest multiple bands of lake effect rain and/or snow will occur south and especially southeast of Lake Erie later Friday into Saturday, with the best potential for snow inland from the lake. Temperatures likely trend below-normal through this period. && .AVIATION /18Z Saturday THROUGH Thursday/... Cold front is about half way across the CWA as of 17Z. Seeing a few returns on radar just to the west of it but with the dry lower levels it will be difficult to be much more than a few sprinkles or a brief shower. Better forcing arrives this afternoon and will move eastward across the region into the evening. MVFR ceilings will arrive with the showers that move/develop across the area through the evening. IFR conditions will develop across NE OH/NW PA with as the colder air changes the rain to snow. Most of the IFR conditions will be inland over the higher terrain. Gradually improvement is expect on Sunday as the bands of snow shift up the lake into western NY. Winds will be gusts at times through the night. Winds become southwest in the wake of the front that is moving eastward across the region this afternoon. Winds shift more to the west overnight. .OUTLOOK...Periods of precipitation may yield non-VFR Monday night into Tuesday. && .MARINE... A cold front extending southwestward over central Lake Erie late this afternoon will exit the lake to the east by early this evening. Behind the front, west winds will increase to 25 knots over the basin and waves will build along the Ohio and PA nearshore waters. A Small Craft Advisory is in effect for all of the nearshore zones for late this afternoon through Sunday with the expiration timed from west to east across the lake. High pressure moves southeast of the lake on Sunday and will allow for winds to decrease and shift to the southwest over the basin for Sunday and the first half of Monday. Low pressure returns to the Great Lakes region on Monday and will extend a cold front over the lake on Tuesday. Strong west to northwest winds will return to the lake and waves will build yet again for the eastern basin and marine headlines are possible for Tuesday into Wednesday. High pressure moves over the lake for Wednesday and winds will become light out of the southwest. Yet another cold front should cross the lake Wednesday night and be followed by a strong high pressure ridge building from the west on Thursday. Winds will shift from southwesterly to northwesterly with the passage of this front. Marine headlines may be needed Wednesday night into Thursday morning. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...Winter Weather Advisory from 8 PM EDT this evening to noon EST Sunday for OHZ012>014. PA...Winter Weather Advisory from 8 PM EDT this evening to noon EST Sunday for PAZ002-003. MARINE...Small Craft Advisory until 10 PM EST Sunday for LEZ147>149. Small Craft Advisory until 10 AM EST Sunday for LEZ142-143. Small Craft Advisory until 4 PM EST Sunday for LEZ144>146. && $$ SYNOPSIS...MM NEAR TERM...MM SHORT TERM...Jaszka LONG TERM...Jaszka AVIATION...MM MARINE...Sefcovic/Jaszka