431 FXUS61 KCLE 281109 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 609 AM EST Mon Jan 28 2019 .SYNOPSIS... Low pressure will move east to southern lower Michigan and then northeast through the lower Great Lakes today and early tonight. A trailing cold front will sweep east across the region this evening and usher Arctic air into the region through Thursday. A trough from the low pressure will linger back over the local area through Tuesday night. High pressure will move east across the region Thursday and Thursday night. Another reinforcing high pressure will build east into the lower Great Lakes by Saturday and will bring a return mild southerly flow to the area for the weekend. && .NEAR TERM /THROUGH TUESDAY/... Latest observations show most of the snow in advance of the low pressure system remains over Illinois. The precipitation will continue to advance east with time this morning into the western portions of the forecast area. Eventually, the precipitation will spread east over the entire area today. Timing still appears to be on track at this time. Clouds advanced east a bit faster than in the forecast so updated to advance clouds further east. Original Discussion... A look at the global northern hemispheric circulation is beginning to show signs that the Arctic air from the North Pole will begin to flow back toward Russia once again in a similar fashion as what occurred through December. This will aid in ejecting the cold air mass expected Tuesday and Wednesday east of the area fairly quickly. This upper level pattern change will support the possibility of stronger ridges building into North America as we head into the weekend. The North Atlantic and Arctic oscillations are indicating a change to a strong positive phase over the next couple weeks and perhaps a warming trend. At any rate, low pressure moving east toward the area today will bring with it precipitation in the form of snow initially. Pressure gradient will support increasing winds across the area from a southerly component and some warm air advection will take place to support a possible mix of rain and snow today into the evening. Will hold off on mentioning any freezing rain at this time even though department of transportation road sensors are reporting temperatures in the teens. Day shift will have to monitor for possible icing if the rain occurs. Otherwise, a general 1 to 3 inches of snow is expected across the area with the storm system. Some light lake effect snow continues at Erie at this time but wind flow is beginning to shift around to the southeast ahead of the low pressure system. This should continue to disrupt the snow band during the morning hours. Latest satellite shows clouds associated with the lake snow band over Erie, PA are beginning to spread out as the shift in the flow begins to interact with the band. Cold front ushering in Arctic air will move through the local area this afternoon and evening. Temperatures will begin to fall behind the cold front and the plummet will continue tonight into Tuesday. Highs in the warm air advection flow today will top out in the middle to upper 30s. Following the frontal passage the cold air will drop temperatures into the teens overnight and will remain nearly steady in the teens Tuesday. Perhaps single digits could be reached late afternoon Tuesday in the western third of the forecast area. Then, it is all down hill as reinforcing Arctic air arrives Tuesday night. The synoptic snow will transition into lake effect snow Tuesday for the extreme northeast snowbelt. Otherwise, snow threat will taper off for the rest of the forecast area Tuesday. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... There increasing confidence in dangerously cold conditions from Tuesday evening through Thursday afternoon. Therefore, a Wind Chill Watch has been issued for the entire forecast area for wind chills below -25F and potentially as cold as -40F. A deep trough will enter the Great Lakes region on Tuesday and continue southeast to over the eastern Lakes by Wednesday. In this trough, a closed 488 dm low will be centered just north of the forecast area and will usher in extremely frigid temperatures into the region with an arctic surface high sliding southeast on the back side of the system for Wednesday night into Thursday. Forecast guidance has been persistent over the last several days with 850 mb temperatures in the -25 to -30C range over the area by Wednesday morning, which will translate to temperatures below zero degrees Fahrenheit at the surface. Temperatures will likely remain below zero Tuesday night through Thursday, and high temperatures across the area may not go above zero degrees on Wednesday for the first time since January 1994 in many locations. Low temperatures on Wednesday and Thursday morning will be the coldest temperatures the region has felt since February 2015 and could break daily records by several degrees. See more on this in the climate section below. A residual trough of low pressure at the surface will keep strong winds over the area during this time period with winds 10 to 20 mph, gusting to 30 to 35 mph. This will translate to wind chills of 25 to 35 degrees below zero, with some spots in northwest Ohio perhaps getting as as cold as 40 degrees below zero. This will allow for life-threatening cold conditions with frostbite and hypothermia possible in the matter of minutes. Aside from the cold temperatures, the Great Lakes have the potential to be active through the period, as arctic air over the non-frozen portions of the lakes will provide moderate to extreme instability to generate lake effect snow. As mentioned in prior forecast discussions, not entirely sold on the extent of lake effect snow in our forecast area, as there are concerns with moisture in the boundary layer and the impact of strong winds, which may not allow for residence time over the lake for good saturation and deep convective bands of snow. Plus, the lake will be freezing up rapidly, which won't completely shut down the lake effect, but it may diminish how much help the lake will give. Finally, mean flow over the lake appears to be southwesterly for much of the period, which is more favorable for snow in end up in western New York, rather than NW PA or NE Ohio. With this, have maintained a 50-60 percent pop over Erie County PA quickly diminishing south and west. If lake effect bands can build further south or mean flow shifts more westerly, then Erie County PA could see more snow than currently forecasted. Elsewhere, conditions should be dry until Thursday night when a weak disturbance will enter the Ohio Valley and give a chance for snow, but some uncertainty there. && .LONG TERM /FRIDAY THROUGH SUNDAY/... Still several differences in the long term forecast guidance to be too confident in much at this point. However, the lone exception is that the cold pattern appears to break as arctic high pressure will continue to the East and warm air advection will begin streaming into the region. Otherwise, the ECMWF depicts a weak clipper system moving to the north of the area for the weekend, while the GFS has a deepening low entering the Great Lakes region on Sunday. For now, just have warming temperatures and generic chance pops for the weekend. && .AVIATION /12Z Monday THROUGH Friday/... Low pressure will move east toward the local area today. The low will spread some warm air into the region today causing the snow to become mixed with rain in the central portions of the area. Ceilings and visibilities will be lowering as the precipitation occurs. Expecting mostly MVFR to brief IFR conditions moving west to east into the area. Snow accumulations about 1 to 3 inches across the area. Winds will increase as well today in advance of the low pressure system. OUTLOOK...Non-VFR Monday through Tuesday morning. More Non-VFR expected late Tuesday night and then mainly northeast snowbelt by Thursday. Possible non-VFR all areas Friday. && .MARINE... Low pressure approaching the Great Lakes region today will allow for increasing winds on the Lake. As this low passes to the north of the Lake tonight strong southeast flow with shift to the south and then southwest for Tuesday. Winds will be in the 15 to 20 knot range, but will be on the increase on Tuesday with a residual trough of low pressure over the region. For now have, winds to 30 knots in the forecast on Tuesday night through Wednesday night, but it's not inconceivable to see a brief period of gales on the lake. Regardless, would likely need a small craft advisory for ice free areas on Tuesday through Thursday. High pressure building into the region on Thursday will relax winds and waves over the Lake and give a reprieve in hazardous marine conditions for Thursday night through Saturday morning. Arctic air entering the region on Tuesday and remaining over the Lake through Friday will allow over considerable ice growth on the lake. There could be some difficulty with the stronger winds, but as winds relax on Thursday and Friday, ice growth will be more certain. In addition, frigid air along with strong winds will pose a heavy freezing spray threat in ice free areas and appropriate headlines will probably be needed later this week. && .CLIMATE... Temperatures this week could approach or break record low temperatures across northern Ohio and NW PA. Here are notable low temperature records/statistics for area climate sites: Record Low Temperatures for January 29: Cleveland, OH (CLE): -17F in 1873 Akron-Canton, OH (CAK): -13F in 1977 Erie, PA (ERI): -10F in 1977 Mansfield, OH (MFD): -14F in 1977 Toledo, OH (TOL): -9F in 1963 Youngstown, OH (YNG): -12F in 1977 Record Low Temperatures for January 30: Cleveland, OH (CLE): -4F in 1873 Akron-Canton, OH (CAK): -6F in 1965 Erie, PA (ERI): -4F in 1915 Mansfield, OH (MFD): -4F in 1934 and 1966 Toledo, OH (TOL): -5F in 1965 Youngstown, OH (YNG): -8F in 1965 Record Lowest High Temperatures for January 30: Cleveland, OH (CLE): 8F in 1977 Akron-Canton, OH (CAK): 7F in 1977 Erie, PA (ERI): 8F in 1977 Mansfield, OH (MFD): 4F in 1977 Toledo, OH (TOL): 8F in 1977 Youngstown, OH (YNG): 6F in 1977 Record Low Temperatures for January 31: Cleveland, OH (CLE): -5F in 1948 and 1971 Akron-Canton, OH (CAK): -5F in 1948 Erie, PA (ERI): -6F in 1899 Mansfield, OH (MFD): -5F in 1971 and 2009 Toledo, OH (TOL): -5F in 1971 Youngstown, OH (YNG): -9F in 1948 Record Lowest High Temperatures for January 31: Cleveland, OH (CLE): 5F in 1971 Akron-Canton, OH (CAK): 8F in 1971 Erie, PA (ERI): 6F in 1971 Mansfield, OH (MFD): 7F in 1971 Toledo, OH (TOL): 6F in 1971 Youngstown, OH (YNG): 5F in 1971 Last Date with High Temperatures Below Zero: Cleveland, OH (CLE): -3F on January 19, 1994 Akron-Canton, OH (CAK): -5F on January 19, 1994 Erie, PA (ERI): -4F on January 19, 1994 Mansfield, OH (MFD): -5F on January 19, 1994 Toledo, OH (TOL): -1F on January 19, 1994 Youngstown, OH (YNG): -6F on January 19, 1994 Note: Mansfield had a high of 0F on February 15, 2015. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...Wind Chill Watch from late Tuesday night through Thursday afternoon for OHZ011>014-020>023-031>033-038-089. Wind Chill Watch from Tuesday evening through Thursday afternoon for OHZ003-006>010-017>019-027>030-036-037-047. PA...Wind Chill Watch from late Tuesday night through Thursday afternoon for PAZ001>003. MARINE...None. && $$ SYNOPSIS...Lombardy NEAR TERM...Lombardy SHORT TERM...Sefcovic LONG TERM...Sefcovic AVIATION...Lombardy MARINE...Sefcovic CLIMATE...