451 FXUS61 KRLX 131739 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 139 PM EDT Fri Sep 13 2019 .SYNOPSIS... Cold front tonight and Saturday with a few showers/storms. Upper ridge returns for next week, brining mainly dry and warm weather. && .NEAR TERM /THROUGH SATURDAY/... As of 121 PM Friday... Diurnally driven Cu field is quickly developing this afternoon with isolated to widely scattered convection being possible. Best chances of convection this afternoon should be across the southern and eastern halves of the CWA where moisture depth is a little greater and thermal inversion is a little weaker. Cu field should quickly dissipate this evening with loss of daytime heating. During the evening, a SSErly LLJ of 20 to 30 kts at 925mb is prog to develop in response to the approach of a front, resulting in at least a light breeze for much of the night. Some showers and a few thunderstorms should develop along the front by late evening across SE OH/NE KY, and western WV...and then progress eastward overnight. The amount of overnight convective coverage is in question, especially given a bit of a downsloping low level flow component and very dry soil moisture (guidance often fails to take into consideration overly dry conditions). Regardless of coverage, some precip should be in the area, but rainfall amounts should generally be low, on average. Precip chances shift to the eastern CWA on Saturday as the front starts to stall near the mountains. Somewhat cooler conditions will be common, given light westerly flow and greater cloud cover. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... As of 240 AM Friday... A surface cold front will be near the Ohio River to start the period. Expect showers and storms to be on the increase across the eastern half of the forecast area Saturday morning as the front moves through, and then come to an end from west to east late afternoon/evening as drier air quickly moves in behind the front as it moves/fades out. Surface high pressure and fairly zonal flow aloft then dominate the remainder of the short term period with overall quiet and warm conditions. && .LONG TERM /MONDAY THROUGH FRIDAY/... As of 240 AM Friday... High pressure will remain in control of the weather through the bulk of the extended period. This should keep us mainly dry, with temperatures running above normal. We may get enough moisture into the area toward the middle of next week to kick off some diurnally driven showers or storms, but a consensus blend kept the forecast dry for now and with no confidence on when and where the best chances will be, opted to keep the consensus output. Should also mention that models continue to struggle to reach a consensus with tropical systems early to mid next week, which adds additional uncertainty to the synoptic pattern. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... As of 112 PM Friday... Cu field is in the process of developing across the region early this afternoon. Field should become rather dense in some areas, especially across southern and eastern portions of the region. Iso to widely sct convection is possible this afternoon, but coverage and chances of impacting aerodromes are currently too low to include in TAFs at this time. However, future amendments may require inclusion of convection. Forecast confidence decreases tonight as the next storm system approaches the area. SSErly LLJ of 20 to 30 kts is prog to develop, which should negate fog development. Low CIGs may develop, however, but certainty in that is rather low at the moment. Regardless, a period of reduced flight rules may occur late tonight. A broken band of convection may try to develop and move from west to east tonight into Sat morning, as a surface front approaches the area. SSWrly sfc winds around 10 kts this afternoon, becoming southerly overnight. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY... FORECAST CONFIDENCE: High this afternoon. Low tonight/Saturday. ALTERNATE SCENARIOS: Lowest certainty is with timing and coverage of convection. Low level cloud cover may not be as significant as currently indicated tonight/Saturday. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 17 18 19 20 21 22 23 00 01 02 03 04 EDT 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H M M M M M L EKN CONSISTENCY H H M M H M M M L L H M PKB CONSISTENCY H H H H H H H H H H H M CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z SATURDAY... Early morning dense river valley fog possible Sunday and Monday mornings. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...RH/RG NEAR TERM...RH SHORT TERM...MZ LONG TERM...MZ AVIATION...RH