Nov 22-24, 2013 Weather Fri evening, Nov 22, 2013 Area Forecast Discussion A minor lake effect snow event is forecast in northeast Ohio. fxus61 kcle 222348 afdcle area forecast discussion national weather service cleveland oh 648 pm est fri nov 22 2013 synopsis... cold front will exit east of the area this evening with a ridge building in from the west. an arctic cold front will push south across the area on saturday with lake effect snow developing. strong high pressure will build east across the ohio valley late sunday. && near term /until 6 am saturday morning/... update...forecast on track. no significant changes. original...area radars continue to show a light drizzle across ne ohio/nw pa late this afternoon. will carry drizzle in the forecast for a few hours with conditions drying out behind the cold front this evening. suface analysis shows one area of low pressure over quebec with a seondary low developing developing north of lake superior. the first low will exit to the northeast tonight with a ridge sharply building into the low levels in advance of the second system. satellite imagery shows the clearing line moving across western lower michigan and will push into nw ohio during the evening. skies will clear except for ne oh/nw pa where enhanced troughing downwind of the lake will aid lake effect cloud developement. temperatures will fall into the upper 20s for inland areas...holding near 30 along the lake. && short term /6 am saturday morning through sunday night/... upper level trough seen on water vapor imagery over canada will surge south over the great lakes region on saturday...pushing an arctic cold front south across the area. the 850mb temperature at churchill manitoba was down to -24c this morning and models are in agreement that the h850 temperature will drop to near -18c by sunday morning. the initial frontal passage will lack moisture and will just carry chance pops for most areas except downwind of lake erie. those areas will see a quick burst of snow with the front and could result in up to an inch of snow accumulation over the higher terrain. a break is expected before the lake effect snow ramps up during the evening as the moisture depth increases with the passage of the upper level trough. the combination of extreme instability over the lake and upslope northwesterly flow will allow lake effect snow showers to fill in across the snow belt. the heaviest accumulations are expected in nw pa where models indicate we will establish a lake huron connection. snowfall rates beneath this band could be 2 inches per hour but hard to define exactly where this band will set. it looks like fairly high chances of it impacting erie and crawford pa. the airmass is cold enough that not expecting the lake to reduce accumulations enough to leave the lakeshore areas out. accumulations in nw pa will exceed 6 inches in many areas but local amounts could exceed a foot by the time the snow ends if the band becomes stationary. have expanded the les watch to include geauga county where the upslope component will cause enough enhancement for accumulations of 4 to 8 inches. the bulk of this will fall on saturday night with the passage of the upper level trough. the rest of the snow belt will see accumulating snow and lake effect snow advisories may be needed in periphery counties. northwest winds will contribute to blusterly conditions with speeds of 15 to 25 mph and gusts to 35 mph. the snow will have a high snow/liquid ratio (15:1 or even 18:1) given the cold airmass and will blow around easily. strong high pressure over the midwest will expand over the ohio valley on sunday and will be accompanied by very dry air. dewpoints fall into the single digits and teens and snow will decrease in coverage from west to east as this dry air intrudes. the complicating factor of this forecast is how long it will take for snow to decrease...given the limited moisture with the system. decided to let the watches continue for another forecast package to allow additional time to consider the moisture quality and placement of lake effect snow bands before making determination on warnings/advisories. heavy snow also not expected to develop until saturday night. && long term /monday through friday/... very few changes to the long term today as the period looks cold with occasional snow showers. will try to start the period off dry on monday. a system will pass to the north on tuesday and drag a cold front across the region. some warm air advection precip could occur as early as monday night but better chances for measurable precip will come with the front. winds will become favorable for lake effect snow late tuesday through wednesday night. moisture appears to be somewhat limited as it will be a dry airmass. as a result...no more than chance pops for the time being. the surface ridge will move just to east of the area on thursday and then linger on friday. this will prevent an airmass change. high temps the entire week will be a good 10 to 15 degrees below normal. && aviation /23z saturday through wednesday/... difficult forecast for the overnight hours. significant drying...at least at midlevels will be coming in overnight. evening nw gusts will subside some and the winds will back more westerly as temporary ridging nudges toward the area. questions will be what will happen with the current ifr/mvfr ceilings. most model guidance wants to clear or scatter that out leaving vfr conditions for morning. one model...the hrrr would like to redevelop at least an mvfr ceiling across the west after 09z and never really get rid of a non-vfr ceiling across the east. have trended the forecast in this more pessimistic direction. models have been too fast all day...and our current ceiling situation has hung on longer than it was suppose to. for saturday...next trough will drop south across the area for the afternoon hours. some scattered snow activity possible with this...the snow showers likely for the snowbelt. this will return conditions to mvfr or lower. winds will also be gusty saturday...with 25 knots for most...30 knots for some. for the extended portion of the cle taf...winds will remain gusty even after 00z sun. outlook...non vfr mainly over ne oh and nw pa saturday night through sunday because of lake effect. non vfr returning late monday night into tuesday and continuing across ne oh/nw pa on wednesday. && marine... with the exception of a few hours later tonight will likely see small craft conditions the entire period. nw flow will continue tonight through sunday. speeds will increase late saturday as a secondary cold front crosses the lake. could get sustained winds in the 25 to 30 knot range for several hours behind the front. winds will become sw on monday as surface ridge crosses the lake. speeds will remain up with sustained winds of at least 20 knots. another cold front will cross the lake on tuesday causing the flow to return to the nw. strong north to nw flow will then continue through wednesday. && cle watches/warnings/advisories... oh...lake effect snow watch from saturday evening through sunday evening for ohz013-014-089. pa...lake effect snow watch from saturday evening through sunday evening for paz001>003. marine...small craft advisory until 7 pm est sunday for lez142>149. && $$ synopsis...kec near term...kec/tk short term...kec long term...kubina aviation...oudeman marine...kubina h2. NW lower MI Lake Effect Snow Watch Statement as of 4:15 PM EST on November 22, 2013 ... Lake effect snow watch in effect from Saturday morning through Sunday morning... The National Weather Service in Gaylord has issued a lake effect snow watch... which is in effect from Saturday morning through Sunday morning. Hazardous weather... * a period of heavier snowfall expected overnight with the passage of the Arctic front. * Heavy lake effect snow showers develop on Saturday and persist through Saturday night. * Lake effect snow accumulations of 5 to 10 inches by Sunday morning with localized accumulations exceeding 12 inches possible. * Gusty northwest winds will produce some blowing snow and single digit wind chill readings. Impacts... * snow covered roads and poor visibility in falling and blowing snow will result in hazardous travel. Precautionary/preparedness actions... * a lake effect snow watch means there is a potential for a large amount of snow in only a few hours. Visibilities and snowfall can vary greatly... impacting travel significantly. To learn more... visit US online at weather.Gov/Gaylord or find US on facebook and twitter. h2. NE OH Lake Effect Snow Watch Statement as of 3:41 PM EST on November 22, 2013 ... Lake effect snow watch remains in effect from Saturday evening through Sunday evening... * accumulations... over 6 inches possible with locally higher amounts around a foot in northwest Pennsylvania where lake effect bands persist. * Timing... lake effect snow will increase Saturday evening and become heavy at times overnight. The heaviest snow will occur from Saturday night through Sunday morning... with snow decreasing Sunday afternoon. * Winds... northwest winds of 15 to 25 mph with gusts to 35 mph on Saturday night... decreasing on Sunday afternoon. * Impacts... motorists should be alert for rapidly changing conditions that occur within bands of lake effect snow. * Temperatures... will fall to the near 20 degrees Saturday night and and hold nearly steady on Sunday. * Visibilities... could be below a quarter of a mile at times. Precautionary/preparedness actions... A lake effect snow watch means that significant winter weather is possible in localized areas within the few days. Stay tuned to NOAA Weather Radio for further details or updates. h2. UP MI Lake Effect Snow Warning Statement as of 12:48 PM EST on November 22, 2013 ... Lake effect snow warning remains in effect from midnight tonight to noon EST Sunday... Hazardous weather... * heavy lake effect snow will start late this evening and continue through Sunday morning... with the heaviest snowfall rates expected Saturday afternoon through Saturday night. * Snow accumulations of 9 to 14 inches are expected over western Luce County west of Newberry... while snowfall of 6 to 9 inches is expected for eastern Luce County. * North to northwest wind gusting to more than 30 mph late tonight and Saturday... especially along Lake Superior... will create blowing snow... sharply reduced visibilities at times... and wind chills below zero. Impacts... * roadways will likely become hazardous and travel may become difficult from snow and blowing snow... especially closer to Lake Superior where the wind is the strongest. * The harsh wind chills will create dangerous conditions for persons staying outdoors for an extended period of time. Precautionary/preparedness actions... * a lake effect snow warning means significant amounts of lake effect snow are forecast that will make travel very hazardous or impossible. * Prepare... plan... and stay informed. Visit www.Weather.Gov/MQT hr. Lake Effect Snow Warning Statement as of 12:48 PM EST on November 22, 2013 ... Lake effect snow warning remains in effect from midnight tonight to noon EST Sunday... Hazardous weather... * heavy lake effect snow will start late this evening and continue through Sunday morning. The heaviest snowfall rates will occur across western Alger County late tonight through Saturday... and across eastern Alger and northern Schoolcraft counties Saturday morning through late Saturday night. * Snow accumulations of 10 to 15 inches are expected. * North to northwest wind gusting to more than 35 mph late tonight and Saturday... especially along Lake Superior... will create blowing snow... sharply reduced visibilities at times... and wind chills below zero. Impacts... * roadways will likely become hazardous and travel may become difficult from snow and blowing snow... especially closer to Lake Superior where the wind is the strongest. * The harsh wind chills will create dangerous conditions for persons staying outdoors for an extended period of time. Precautionary/preparedness actions... * a lake effect snow warning means significant amounts of lake effect snow are forecast that will make travel very hazardous or impossible. * Prepare... plan... and stay informed. Visit www.Weather.Gov/MQT h2. Sat morn, Nov 23 AFD fxus61 kcle 231451 afdcle area forecast discussion national weather service cleveland oh 951 am est sat nov 23 2013 synopsis... an arctic cold front will push south across the area today. strong high pressure will build east across the ohio valley late sunday and then move east by tuesday as another cold front moves across the region. && near term /until 6 pm this evening/... so far it has been a fairly quiet morning weather wise. do not see the need for any major changes to the forecast for the morning update. currently there are mostly clear skies over northwest ohio and mostly cloudy skies over northeast ohio and northwest pennsylvania. clouds will fill in across the entire area over the next several hours as the cold front makes its way southeastward. original discussion...the second cold front with the arctic airmass will move across the area today...especially this afternoon. some snow showers will occur with the front...the only place that could have some accumulations would be ne oh and nw pa and that would be mainly around an inch. some inland locations over nw pa could have up to two inches of snow. the warning starts at noon which may be ok especially over inland pa as the front moves through. temperatures may warm a few degrees today and then cool a few degrees after the frontal passage. && short term /6 pm this evening through tuesday night/... an upper trof will be moving east of the area tonight. plenty of cold air will be flowing in. by late tonight the lake and 850 mb temperature difference will be around 25c and the lake and 500 mb temperature difference will be around 47c (40c difference is unstable). these values are very unstable. moisture is ok especially over ashtabula county and nw pa. northwest flows are usually not conducive to heavy snow unless you get a fetch from another lake like lake huron or lakes superior and michigan. nw pa and ashtabula county will get a band off of lake huron. if you are not in the band your snowfall amounts may not be heavy. added blowing snow because of the gusty winds and thunder because of the instability. some bands of lake effect may occur with a connection from lake superior. tried to bump up the amounts in the areas that may get those bands which would be cleveland southeast and another band could be farther west. still some uncertainty with that. the snowfall amounts are not expected to be high enough for an advisory but this will have to be watched. cancelled the lake effect snow watch for lake and geauga counties...they will get some lake effect snow but the amounts are not expected to be high enough for a warning. they also don't seem high enough for an advisory at this time because they should not get a band of lake effect snow off of huron. this will be monitored by the next shifts. with ridging and drier air working in for sunday this will decrease the snow showers especially over ne oh and eventually over nw pa. a break for much of monday and then a chance of snow showers again monday night into tuesday night as another cold front moves through. used a blend of guidance for the temperatures...they are tough depending on the sky cover...winds etc. && long term /wednesday through friday/... very few changes to the long term. models continue to move front across eastern lakes on wednesday. for now will continue with chance pops in the east for wednesday and wednesday night as models continue to show very dry airmass. that said with 850 mb temps of minus 12c lowered temps a couple of degrees. both the gfs and ecmwf in reasonable agreement moving ridge of high pressure across great lakes on thursday. models diverge significantly on friday. gfs continues to move a low pressure system across the northern lakes on friday. the ecmwf on the other hand tracks the low across western ny state. since low confidence on track of the low will go with continuity for now and keep fridays forecast dry. && aviation /14z saturday through wednesday/... cold front nw of the thumb of michigan will move across the area late morning into early afternoon. will see some light snow with the front...with possibly up to an inch of snow by this evening. behind the front winds will shift to the nw with gusts up near 30 knots. lake effect snow will develop overnight as the 850mb temps dip to minus 18c. lake effect snow warning remains in effect for nw pa and ashtabula county in ohio. outlook...non vfr mainly over ne oh and nw pa tonight through sunday because of lake effect. more widespread synoptic snow expected late monday night into tuesday and continuing across ne oh/nw pa on wednesday in lake effect shsn. && marine... extended small craft advisory into tuesday. strong nw flow will set up behind the front with winds up to 30 knots possible. nw flow with winds 15 to 25 knots will continue into sunday evening. winds will slacken sunday night for a few hours...but decided not to end small craft as sw flow will increase to 15 to 25 knots monday morning ahead of next front. next cold front will push across the lake on tuesday causing the flow to return to the nw. strong north to nw flow will then continue through wednesday. && cle watches/warnings/advisories... oh...lake effect snow warning until midnight est sunday night for ohz014-089. pa...lake effect snow warning until midnight est sunday night for paz001>003. marine...small craft advisory until 11 am est tuesday for lez142>149. && $$ synopsis...kieltyka near term...kieltyka/schepel short term...kieltyka long term...djb aviation...djb marine...djb #weather - #lakeerie