Area Forecast Discussion
Issued by NWS Cleveland, OH
Issued by NWS Cleveland, OH
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192 FXUS61 KCLE 101046 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 646 AM EDT Thu Oct 10 2024 ...12z TAF Aviation and Near Term Forecast Update... .SYNOPSIS... High pressure will build over the Great Lakes and Ohio Valley today into tonight. A warm front will lift northeastward across the region on Friday. A stronger cold front will sweep across the region Sunday bringing much cooler, fall-like weather early next week. && .NEAR TERM /THROUGH FRIDAY/... 645 am update... There are no adjustments needed with the ongoing near term forecast at this time. Previous discussion... A quiet weather pattern will be around the next couple of days thanks to a large high pressure that is currently over the Upper Great Lakes this morning. The center of this high pressure will track southeastward through the Great Lakes region into northern Ohio by this evening. Skies are clear this morning and will remain that way through Friday. We may see a few small fair weather clouds try to sprinkle the skies this afternoon and again Friday afternoon but overall we are expecting mostly sunny skies today and tomorrow. It is starting off this morning kinda chilly for areas away from the immediate lakeshore and urban areas with weather stations reporting mid to upper 30s in the favored cooler spots and valleys. One note to mention, we cancelled the frost advisory for the 2 counties zones in NWPA early this morning. There are two reasons for that early cancellation. The temperatures in far NWPA did not get as cool as much as previously forecasted overnight due to lingering lake effect clouds. The second reason was to be proactive and issue a larger frost advisory for NEOH and NWPA for tonight`s potential frost. The Temperatures will be a touch cooler than seasonable averages for mid October today. High temps will range from the upper 50s over NWPA and far NEOH. Low 60s are expected for NCOH and mid 60s for NWOH for high temps this afternoon. Clear skies and light winds with a dewpoints in the low to mid 30s is a good setup for patchy to areas of frost for the Central Highlands region and most of NEOH and NWPA. Obviously the immediate lakeshore communities will not have to worry about frost with this round of cooler weather thanks to lake water temps still in the mid to upper 60s. We have the initial frost advisory for areas along and east of I-71. Friday morning temps will start out in the lower to mid 30s across most of NEOH and NWPA as well as central Ohio. NWOH will stay a few degrees above that in the upper 30s to lower 40s late tonight into early Friday morning. High pressure will move towards the East Coast on Friday and a warm front will lift across the region. After a frosty start Friday morning for some folks, afternoon temperatures will make a very nice recovery into the upper 60s for NWPA and low 70s for NEOH. It will be even warmer for north central and northwest Ohio with mid to upper 70s for high temps Friday afternoon with mostly sunny skies. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... A cold front will sag in from the north Friday night before stalling over northern or central Ohio into Saturday. Upper support and moisture will be limited with the initial frontal passage. Enough models still have just a bit of QPF over Lake Erie or our adjacent northern land zones to justify a 20% POP for late Friday night into early Saturday morning, though many areas may just see an increase in clouds and wind shift with the front. A flat shortwave ahead of an approaching larger upper trough is expected to track along the front Saturday afternoon into Saturday night. Moisture depth will improve some, with the added support from the shortwave contributing to greater potential for a light QPF rain event near and north the stalled frontal spreading in from the west during the day Saturday and continuing east Saturday night. Have 20-30% POPs spreading into most of northern Ohio on Saturday as it`s uncertain how quickly we`ll moisten enough to start seeing rain, with POPs increasing to 40-60% area-wide Saturday night as confidence increases. Nothing hazardous but it is rain potential on a weekend. A potent upper trough will carve out over the Great Lakes Sunday into Sunday night, pushing a strong cold front through the area and ushering in the chilliest airmass of the relatively young autumn season for early next week. Guidance still disagrees on the degree of cyclonegenesis over the eastern Great Lakes ahead of the digging trough Sunday into Sunday night, with some of the disagreement still seemingly tied to how amplified the weaker lead shortwave that will bring our initial rain chances Saturday-Saturday night is. However, there is better agreement in low pressure developing just to our north/northeast on Sunday and likely deepening below 1000mb by some point Sunday night. This increases confidence in shower potential for Sunday, especially from northeastern OH into northwestern PA where 60-70% POPs are in the forecast with lower but still mentionable (30-50%) chances farther west/southwest with the front. As the low pressure pulls away Sunday night we`ll get into cold air advection and perhaps some wrap-around moisture amid west-northwest cyclonic flow. This will focus the greatest shower chances east and southeast of Lake Erie into northeast OH/northwest PA where likely to categorical (60-80%) POPs are in the forecast. Don`t completely remove POPs outside of the lake effect in the somewhat moist cyclonic flow, though POPs and potential QPF are noticeably lower outside of where the lake will contribute to the showers. Lows Friday night will be much milder than recent nights, mainly in the 50s with a few 40s possible in a few cooler spots in far northeast OH/northwest PA. Highs Saturday will generally rise into the 60s to perhaps low 70s, dependent on how long rain does or doesn`t hold off. Lows Saturday night will range from the mid to upper 40s in northwest PA to the low to mid 50s towards Findlay and Marion. Highs on Sunday should still rise into the 60s to perhaps near 70 south if there are breaks in the showers/clouds. Lows Sunday night will get into the 40s. Wind gusts in the initial push of cold air advection Sunday afternoon into Sunday night may exceed 30 MPH, though unless we see trends for much more robust cyclongenesis should remain safely below advisory criteria. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... A longwave trough will settle over eastern Canada and the eastern U.S. for Monday and Tuesday as surface low pressure exits towards Atlantic Canada. The trough will start exiting east towards midweek as surface high pressure builds in. Guidance is in better agreement on the overall pattern early next week compared to a day ago, though finer details will certainly still change at this range. Expect chilly and somewhat moist north to northwest cyclonic flow on Monday to gradually back to a more west-northwesterly direction Tuesday and Wednesday. Various vort maxes and associated subtle surface troughs will drop through Monday and Tuesday before the longwave trough starts shifting east. This setup will support occasional lake effect showers through at least early Wednesday, with activity starting to wane on Wednesday if high pressure builds in as currently expected. Showers may be pretty widespread as far west as Sandusky and Mansfield in the north-northwest flow on Monday before gradually shifting east Tuesday and Wednesday. The trough aloft will steepen lapse rates enough that there should be hit or miss showers outside of the lake effect Monday into Tuesday, especially during the afternoon hours when diurnal heating will help enhance low-level instability a bit. The airmass will likely be its chilliest Monday night and Tuesday when 850mb temperatures will dip to -2 to -4C with 1000-500mb thickness values bottoming as low as 530dm. Not unheard- of for mid-October but solidly chilly for the calendar. Fans of winter weather will note that both values would typically support snow as the precip type in the middle of winter...the boundary layer is much warmer in October which will cause the showers to largely fall as rain, though at the least a bit of small hail or graupel could be possible in any more robust lake effect showers, especially Monday evening through Tuesday morning when temperatures aloft appear coldest. Our "forecast builder" did give about 4 grid points of a rain/show mix late Monday night in the highest terrain of eastern Crawford County PA and did leave it as the temperatures aloft, as progged, could support a few wet flakes out there. Temperatures will be cooler than normal for this period with highs in the 50s and lows in the 30s to low 40s. It remains possible if not likely that the higher elevations across far northeast OH and northwest PA stay in the 40s for highs on Tuesday. It will be somewhat breezy Monday and Tuesday but nothing hazardous. While the airmass is chilly enough for frost/freeze concerns the first half of next week, the potential for some wind and clouds does cast quite a bit of uncertainty. Overall, this potential may be highest closer to midweek when surface high pressure builds closer to the area. && .AVIATION /12Z Thursday THROUGH Monday/... VFR conditions will prevail for this early morning TAF aviation weather update. A large high pressure system over the Great Lakes region is dominating our weather pattern and will continue to bring nice, quiet flying conditions today through Friday. Mostly clear skies conditions will also continue along with light winds of 4 to 8 knots. Generally winds will start out from the north or northeast direction today gradually becoming easterly or southeasterly by Friday morning. Most areas will see a period of calm or light and variable winds this evening as the center of the high pressure tracks across northern Ohio. Outlook...Scattered rain showers with non-VFR conditions possible late Saturday into Sunday associated with a cold front. Lake Effect clouds and scattered rain showers will be likely Sunday through Tuesday night, especially downwind of Lake Erie and the Snowbelt region. && .MARINE... North-northeast winds will gradually diminish today. Still some 3 footers early this morning in the central nearshore waters, though waves are also gradually subsiding. High pressure will be in control and keep the lake tranquil through Friday morning. A cold front will sink across the lake Friday night. Southwest winds will pick up to 15-25 knots Friday afternoon and evening ahead of the front, generally stronger farther east. Winds will flip around to the north late Friday night into Saturday behind the front, with winds diminishing fairly quickly by morning. Waves will build to 3-6 feet in the central and eastern basins in the southwest flow ahead of the front Friday afternoon and evening, with a brief period of onshore flow right behind the front Friday night. This will likely prompt a Small Craft Advisory, especially from Avon Lake points east. Another brief lull in conditions is expected Saturday through a portion of Sunday. A strong cold front will cross the lake on Sunday, followed by a good push of cold air advection behind a developing low pressure over the eastern Great Lakes. This low pressure will exit towards Atlantic Canada early next week. While guidance still disagrees on how quickly the low pressure will deepen Sunday into Sunday night, the strong cold front and associated cold air advection over the warm lake will support an increase in winds to out of the north or northwest to 15-25 knots Sunday afternoon into Sunday night. Chilly cyclonic flow continues through at least early Wednesday before high pressure tries to start nosing in, keeping brisk west to northwest flow going through at least early Wednesday before potentially subsiding. Small Craft Advisories will likely be needed for most or all of the lake starting some point on Sunday through Sunday night, with decent potential for the advisories to need to linger well into next week east of The Islands. There is some potential for a brief period of stronger winds to 30kt or so Sunday afternoon or night if the low pressure deepens quicker than currently projected, though this scenario is low confidence (20%) and the forecast reflects a weaker solution. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...Frost Advisory from midnight tonight to 9 AM EDT Friday for OHZ010-013-014-020>023-029>033-037-038-047. PA...Frost Advisory from midnight tonight to 9 AM EDT Friday for PAZ002-003. MARINE...None. && $$ SYNOPSIS...Griffin NEAR TERM...Griffin SHORT TERM...Sullivan LONG TERM...Sullivan AVIATION...Griffin MARINE...Sullivan