Area Forecast Discussion
Issued by NWS Wilmington, OH

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000 FXUS61 KILN 240936 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 436 AM EST Fri Feb 24 2017 .SYNOPSIS... A low pressure system will track from the mid Mississippi Valley this morning into the Great Lakes tonight with an associated cold front pushing quickly east across the Ohio Valley overnight. Warm southerly flow ahead of the front will lead to unseasonably warm conditions today. Widespread showers and thunderstorms are expected tonight as the cold front moves through. More seasonable temperatures will spread into the area for the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Surface low pressure is centered over northeast Missouri early this morning with a warm front extending east across Illinois and Indiana and into northern Ohio, just to the north of our fa. With our area in the warm sector, skies have generally gone partly cloudy and temperatures have not dropped off that much, mostly running in the mid to upper 50s attm. The surface low will shift into southwestern lower Michigan by late this afternoon with an attendant cold front pushing east into western Indiana by late afternoon. Warm southerly low level flow will persist ahead of the front with gusts in the 25 to 35 mph range possible. This will help push temperatures up into the low to mid 70s for highs today while dewpoints are forecast to creep up into the mid to upper 50s through the afternoon. This combined with increasing mid level lapse rates will allow for destabilization through the day with mucapes pushing up into the 1000 to possibly 1500 J/KG range this afternoon. However, forecast soundings are showing a decent warm layer between 5-10K feet and this will result in a fairly strong cap through much of the day. As a result, will maintain a dry forecast across most of our area through this afternoon. The cap will begin to break down late this afternoon across the far west/northwest so will allow for some lower chance pops to work in there late this afternoon. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... The cold front will push east across our area this evening and into the overnight hours. As the front approaches, the cap will continue to weaken and with better mid and upper level forcing moving in from the west, expect fairly rapid shower and thunderstorm development across our west early this evening, then spreading east through late evening into the early morning hours. Some of the higher res CAM models are indicating two lines of pcpn developing across our west, one along a pre frontal trough and then another along the cold front, before eventually congealing into more of a single line across our east through late evening and into the early morning hours. Impressive deep layer shear values will spread in from the west through the evening hours and this will be coupled with an increase in both the 0-1 km and 0-3 km shear values as the front approaches. This will support a primarily damaging wind threat but with cooler air moving in aloft and increasing mid level lapse rates, some hail will also be possible. Several of the higher res models are also hinting at the possibility of a few quasi-discrete cells early in the period across the west. This coincides with a bit of an uptick in updraft speed/helicities across western portions of our fa in the 23z-02z. This will result in an isolated tornado threat through the early evening hours. As the storms transform into more of a QLCS through late evening, the severe threat will transition more to just a damaging wind threat, although an isolated tornado will still be possible with any stronger rotations within the line. Temperatures will remain up ahead of the front but then begin to drop off fairly quickly from the west later tonight as CAA developing in the wake of the front. Lows tonight will range from the mid 30s west to the mid 40s east. Some wrap around moisture will work back into the area through the day on Saturday as the mid level trough axis pivots east across the region. This will result in the possibility of a few rain/snow showers through the day. In addition, a fairly tight pressure gradient combined with some continued low level CAA will lead to gusty winds in the 25 to 35 mph range on Saturday. Temperatures will also struggle to rise much, with readings ranging from the upper 30s west to the upper 40s east. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Surface high pressure will be centered over Tennessee and Kentucky Sunday morning allowing for temperatures in the mid to low 20s. During the afternoon Sunday surface high pressure will push east with clear skies slowly giving way to some cirrus in the afternoon. This is thanks to a broad upper level trough centered over Canada with pieces of energy rotating east through the base of the trough. By Monday morning the next piece of energy will approach the area from the west. The ECMWF and GFS are slightly different here on a piece of energy that starts out in Southern California on Sunday and eventually pushes east across our area Monday. The ECMWF and GFS both weaken the energy but the GFS holds the energy together slightly longer than the ECMWF. This allows light precip to push into the area Monday morning. The ECMWF solution just doesn`t have enough energy left with the system to produce QPF. Looking at the soundings from the GFS it looks like rain/ snow will be the likely p- type starting off Monday before changing over to all rain Monday afternoon. The ECMWF solution produces quite a different solution though and have kept PoPs chance at best for now. Monday night into Tuesday morning the GFS and ECMWF continue to diverge on solutions with timing between the models moving out of phase. Both models show an upper level disturbance across the Western United States which amplifies and heads east across the forecast area through the middle of the work week. The ECMWF is slower and slightly weaker with the system compared to the GFS. The ECMWF pushes a wedge of PV ahead of the system though and allows rain to start Monday night while the GFS is now slightly more delayed with the onset of precipitation. A warm front will then lift across the area Tuesday allowing temperatures to climb close to 60 degrees again. A surface low will then form Tuesday into Wednesday and push northeast towards Michigan with a cold front extending from the low down to the Gulf Coast. The GFS being much quicker with the energy has the cold front clearing the CWA Wednesday morning while the ECMWF has the cold front clearing the area Wednesday evening. The Canadian is a good compromise between the two and have trended the forecast this direction. For the end of the work week northwest flow will develop on the back side of the trough axis only to have an upper level disturbance push southeast towards the forecast area. As of now both the ECMWF and GFS have the system more across our northeastern zones and therefore have trended the chance of precipitation higher across the aforementioned area. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... The warm front has pushed north of the area and with it, the threat for additional showers through the early morning hours. In a continued WAA pattern, expect to see sct-bkn mid to high level clouds persist through daybreak. Meanwhile, a 35-45 knot 925mb to 850 mb low level jet will rotate up into the area through the morning hours and this will lead to some marginal LLWS, particularly through daybreak or so and at the western TAF sites. A low pressure system currently in the mid Mississippi Valley will lift northeast into lower Michigan through this evening. An associated cold front will push east across Indiana and into Ohio through this evening. It looks like we will remain capped through much of the day, but the cap will weaken late this afternoon and into this evening as the front approaches. This will allow for some sct to bkn thunderstorms to develop and push east across the area through the evening hours tonight. In addition, gusty southerly winds into the 20-30 knot range will develop later today ahead of the approaching front. OUTLOOK...MVFR ceilings and visibilities possible Saturday and Monday. && .CLIMATE... Record High Temperatures Date CVG CMH DAY Fri 2/24 72(1930) 72(1961) 67(1930/1961) February Record Highs CVG 76 set 2/10/1932 CMH 75 set 2/26/2000 DAY 73 set 2/11/1999 and 2/25/2000 && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...JGL NEAR TERM...JGL SHORT TERM...JGL LONG TERM...Haines AVIATION...JGL CLIMATE... is the U.S. government's official web portal to all federal, state and local government web resources and services.