351 FXUS63 KPAH 252014 AFDPAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 314 PM CDT Sat Oct 25 2014 .SHORT TERM...(Tonight through Tuesday) Issued at 314 PM CDT SAT OCT 25 2014 A weak surface front has pushed through the region today. The main impacts were northwest winds and some drying across the northern half of the area. The northwest winds actually brought warmer low- level air across the region, so would be hesitant to call it a cold front. Anyway, this boundary will become stationary tonight, leaving light winds and clear skies across the region. The statistical guidance is hammering on dense fog development in the better moisture over southeast Missouri...much of west Kentucky and adjacent portions of southern Illinois. Am somewhat concerned for low cloud development in this moist environment, so will only mention patchy dense fog in the grids and give it a mention in the HWO for now. If confidence increases this evening, then a Dense Fog Advisory may be necessary. Winds will be veering to the southeast Sunday, and there is some conflict in temperature guidance. The NAM/MET is several degrees cooler east of the Mississippi than the GFS/MAV. Given today's warmth, figure the MAV is the way to go. South winds over 5kts are expected to persist through Monday night, and that should lead to a mild night. Generally went a bit above consensus guidance for lows. Monday will be breezy and quite warm ahead of our next weather- maker. Went closer to the warmer GFS/MAV guidance again for highs. Much of the area will push the middle 80s. Strong south southwest winds will continue through Monday night, so went above statistical guidance for lows again. Our next storm system will push a cold front and area of convection eastward into the area between 06Z and 12Z Tuesday. The 12Z ECMWF and GFS are in decent agreement in bringing the convection to near the Wabash and Ohio rivers by 12Z Tuesday. The front and convection will then push eastward through the remainder of the area into Tuesday afternoon. The front will become more aligned with the upper flow as it gets to the KY/TN border, so it may slow up and linger a bit in the southeast. The 12Z models all show a nice area of negative Showalter Indices and even some negative LI's at times with the band. Will therefore mention thunder throughout the event. Precipitable water values will climb to 1.5"-1.7" range, which is climatologically high for late October, so would not be surprised to see some locally heavy rainfall, especially Tuesday afternoon in the southeast. .LONG TERM...(Tuesday Night through Saturday) Issued at 314 PM CDT SAT OCT 25 2014 At the beginning of the extended period, there may be some rapidly diminishing convection in the sern half of the PAH forecast area. Otherwise, a drier air mass will invade the region under wnwrly flow aloft, providing mostly clear and cooler than average conditions through Wed night. There is some question as to whether anything measurable will fall Thu/Thu night as the overall pattern across the CONUS amplifies, and a fast-moving mid level shrtwv strengthens and moves into the Midwest. There have been some hints among the med range models, including the 12Z ECMWF, that enough lift and moisture convergence may develop across parts of our area for some light rain to occur during this period. However, at this time the forecast is held to "non-measurable" Thu/Thu night, except for nrn Pike County IN Thu night, due to the sporadic nature of the recent model solutions. Model consensus seemed to suggest some possibility of measurable pcpn lingering into Fri due to shrtwv energy passing through. At this time, this is where showers were included in the forecast for roughly the ern half of the area. Some of what the initialization blend suggested today was influenced by the 00Z ECMWF model's development of a mid level low (with sfc reflection) over the PAH forecast area, not repeated in the 12Z version. However, by Fri evening, the ECMWF and GFS do close a mid level low over the nern CONUS, with fast nrly mid level flow, and a cold advection pattern, to its sw. This will provide a noticeable cool-down for next weekend, with freezing temps possible. && .AVIATION... Issued at 1227 PM CDT SAT OCT 25 2014 A weak cold front is trying to push through the region this afternoon. It is forecast to stall out just south of the area tonight, and then come back as a warm front Sunday. The front will bring some drier air into KEVV and KOWB this afternoon. This should prevent significant fog formation late tonight, despite clear and nearly calm conditions. Low-level moisture will likely remain over KCGI and KPAH through the period. Would not be surprised to see MVFR or even IFR ceilings develop tonight, but guidance is strongly indicating IFR or lower fog formation at both sites. Bottom line is that impacts are likely at both locations tonight into early Sunday. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM...DRS LONG TERM...DB AVIATION...DRS