area forecast discussion 100 pm edt thu apr 9 2015 fxus61 kcle 091700 afdcle national weather service cleveland oh synopsis... an area of low pressure in the plains will move into the great lakes tonight. showers and thunderstorms will develop across the region into friday as a result. a cold front will come through the area friday...followed by high pressure on saturday. && near term /through tonight/... update...no big changes for the afternoon. original...in northeast counties...patchy dense fog will continue for the next few hours...expected to erode as convection moves east. second area of convection developing in indiana associated with the low level jet and an outflow boundary. this feature will move east into ohio later this morning. convection will refocus this afternoon when the low level jet intensifies with the deepening low to our west.with concerns for severe weather...the best instability will be in the afternoon...however concerned about the development in indiana and how that may limit the convection in oh around that same time. it is possible we could see a respectable break in the convection this afternoon...which could allow more time for the air mass to destabilize ahead of the front. any redevelopment tonight will have severe potential with the synoptic scale boundary moving towards the region. the shear is impressive and unidirectional. will see storms moving around 45mph to the e/ne...with some downburst/damaging wind potential. freezing level is around 11k ft...so hail certainly a possibility. pw values unusually high...coming in around 1.2-1.5"...which is 2 standard deviations above normal for this time of year. this will support high rainfall rates with any strong cell. the recent rain has reduced the amount of water the basins can handle before they flood...so flash flooding and isolated river flooding threat heightened as well...mainly where storms train. have a flash flood watch for the southern 1/3rd of counties as these areas have received the most rain in the last few days and subsequently are more susceptible to flash flooding. conditions will change little into the overnight hours so continue with high pops for thunderstorms. && short term /friday through sunday night/... the front will push through the area early friday with dissipating precipitation from west to east. on the increase will be winds as boundary layer mixing could support wind gusts to 45 mph. temperatures will fall in the afternoon as the cold air advection moves in...and dew points will plummet. the surface low will pass by to the north friday night...with enough support for some light rain showers...possibly mixed with some snow flakes which will melt on contact with the ground. high pressure builds in for saturday with temperatures returning to near normal through sunday. && long term /monday through wednesday/... models in good agreement on sunday with high pressure shifting east of the forecast area and moving off the mid atlantic coast. so sunday should be warmer and dry. timing of the next system still in doubt...gfs brings warm front into area with chance of precip monday night while ecmwf a little slower. for now will just go low chance pops monday night. both models continue to move the next wave through on tuesday. && aviation /18z thursday through tuesday/... rounds of shra/tsra will continue to affect the area into fri morning until a cold front sweeps across the area to end the threat. widespread vfr should be the predominate conditions outside of the convection with areas of mvfr/local ifr in the heavier tsra. south to ssw winds will increase this afternoon and tonight to be gusting 25 to 35 knots tonight with gusts around 40 knots on fri. the stronger tsra can easily produce gusts to 50 knots with some large hail possible. outlook..some non vfr possible across nrn oh/nw pa late friday and fri night then just nw pa for early saturday morning. non vfr possible again for monday. && marine... east-northeast winds on the lake will veer to the south-southeast during the afternoon hours as a warm front lifts northward. winds will then steadily increase ahead of a cold front that is expected to cross the lake friday morning. a small craft advisory will be needed for the west of willowick where there is open water late tonight and through the day friday. not expecting sustained winds to exceed 30 knots over the stable lake...except possibly for a short time right with the frontal passage. this will have to be monitored. winds will diminish friday evening and will be under 15 knots through saturday. high pressure then move across the lower lakes/ohio valley over the weekend. a cold front looks to cross the lake monday morning. && cle watches/warnings/advisories... oh...flash flood watch through friday morning for ohz029>032- 036>038-047. pa...none. marine...none. && $$ synopsis...jamison near term...jamison/tk short term...jamison long term...djb aviation...adams marine...djb/oudeman