Area forecast discussion National Weather Service Charleston WV 423 PM EDT Friday may 24 2013 Synopsis... chilly high pressure takes charge tonight into Saturday. Warm front lift north into the Ohio Valley and West Virginia early Tuesday. A warming trend expected Memorial Day through next week. && Near term /through Saturday/... very tough forecast tonight regarding frost/freeze potential. Dewpoints currently straddling the marginal threshold for frost tonight given afternoon mixing. Not sure if these go lower next few hours before recovering this evening. Guidance for metropolitan areas in The Lowlands run 32 to 40f from khts to kcrw. H925 winds stay up around 20 kts overnight as surface high builds in to allow winds at the ground to try to go calm. All of this complicates matters for expanding frost advection. However...given time of year and fact that most folks have some of their veggies in the ground along with annual plant investments...felt prudent to lean a little Liberal and expand to encompass rest of County Warning Area save for S Coal fields to SW Virginia. Outlying areas will see best shot of frost. Headline should Garner more attention for folks to take precautions to be on safe side. Also expanded freeze warning to Raleigh based on guidance ranging from 28f to 33f. They will have get under inversion though given h925 winds off models overnight. Other concern is stratus overnight across the north. NAM has been way too fast in eradicating the low level moisture vs RUC which has been pretty steady. RUC shows clouds lifting and scattered this evening across the north before redeveloping in north mountains by 06z. NAM keeps entire column dry but has not handled today well at all. So will lean toward RUC and redevelop some stratus in north mountains late tonight. This may keep temperatures up tonight especially in valleys...but still feel at or below freeze temperatures will be realized. Upper trough axis shifts to East Coast on Sat with some recovery in temperatures compared to today. Inherited temperatures looked good and only needed tweaking some...mainly across the north. && Short term /Sunday night through Monday night/... made modifications to the short term forecast as follows: High pressure will be in control through the weekend...keeping dry conditions areawide. Models show a middle level shortwave...evident in 500 mb charts...under northwest flow aloft...moving across southern Ohio...southeast into northwest Kentucky. Removed any probability of precipitation for the weekend as moisture looks very limited over WV. In fact...there could be some clearing Saturday night into Sunday morning...keeping temperatures at or just below freezing over Pocahontas and Randolph counties. Included patchy frost over northeast mountains. High pressure moves east over the Middle Atlantic States keeping influence over WV for a dry Sunday through Monday night. Minor changes to temperatures through the period...perhaps a couple degrees lower closer to the cooler met. && Long term /Monday night through Friday/... another shortwave under northwest flow aloft passes across southeast Ohio and WV Monday and Tuesday. At the same time...a warm front lifts north into southern Ohio...across WV and Virginia oriented west to east by 12z Tuesday. These two features will be capable to produce showers and storms late Monday into Tuesday as the warm front moves north of the area by early Wednesday. Increased probability of precipitation to chance including thunder in weather grids accordingly. High pressure takes control by early Wednesday providing dry weather with a slow warming trend through the rest of the week. Tweaked couple of degrees down from HPC guidance in the extended periods. && Aviation /20z Friday through Wednesday/... stratocu should begin to dissipate from west to east by this evening. Exception being north lowlands and especially north mountains where MVFR stratus may redevelop after 06z. Have kekn with some broken MVFR bases as a result. Otherwise surface high will build in after 09z with slackening winds this evening with loss of sun. Northwest flow aloft tonight and tomorrow. May see some fog hug warmer rvrs which may affect river terminals. Have some MVFR visibility at this time with bl winds hanging onto a bit of a puff. VFR conditions return for all tomorrow with just some passing middle clouds. Forecast confidence and alternate scenarios through 18z Saturday... Forecast confidence...medium. Alternate scenarios: extent of fog overnight in question. Stratus may not redevelop across the mountains as forecast. Experimental table of flight category objectively shows consistency of weather forecast office 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 20 21 22 23 00 01 02 03 04 05 06 07 EDT 1hrly 16 17 18 19 20 21 22 23 00 01 02 03 crw consistency h h h h h h h h h h M M heights consistency h h h h h h h h h h h h bkw consistency h h h h h h h h h h M M ekn consistency M M M M M M M M M M M M pkb consistency h h h h h h h h h h h h ckb consistency h h h h h h h h M M M M After 18z Saturday... IFR conditions possible in fog early Saturday morning. && Rlx watches/warnings/advisories... WV...frost advisory from 2 am to 8 am EDT Saturday for wvz005>011- 013>020-026>032-039-040. Freeze warning from 2 am to 8 am EDT Saturday for wvz035>038- 046-047. Ohio...frost advisory from 2 am to 8 am EDT Saturday for ohz066-067- 075-076-083>087. Kentucky...frost advisory from 2 am to 8 am EDT Saturday for kyz101>103- 105. Virginia...none. && $$ Synopsis...arj/30 near term...30 short term...arj long term...arj aviation...30