Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/27/18

National Weather Service Jackson KY
1045 PM EST Mon Feb 26 2018 .UPDATE... Issued at 1045 PM EST MON FEB 26 2018 A few adjustments were made to hourly temperatures and dewpoints based on trends in observations. However, this led to no substantial changes at this time. Under high pressure, low temperatures will be the coldest they have been in about a week, though they will still be nearly 5 degrees above normal. UPDATE Issued at 805 PM EST MON FEB 26 2018 High pressure continue to build into the area at the surface and aloft. Temperatures for a few eastern valley locations have decoupled and were dropping off a bit quicker than the previous forecast. Hourly temperatures in these locations have been updated based on recent trends. In addition, a couple of the min temperatures for normally colder locations were lowered a degree or two. Otherwise, no changes were made at this time. && .SHORT TERM...(This evening through Tuesday night) Issued at 330 PM EST MON FEB 26 2018 19z sfc analysis shows a moderately strong area of high pressure moving through the Ohio Valley bringing some much welcomed drying and sunshine to the area with the morning clouds now off to the east. Winds remain light and generally from the northeast. The sunshine has helped lift temperatures into the mid 50s most places with dewpoints settling into a range from the mid 20s north to upper 30s southeast. The models are in good agreement aloft through the short term portion of the forecast. They all depict a weakening band of energy pulling away from the area to the east while a broad ridge slides overhead tonight. This ridge will hold through the day Tuesday before starting to break down on its northern fringe over Kentucky under the influence of minor energy waves spreading east in increasingly southwest flow. Deep layer southwest flow will then be the rule for Wednesday morning and beyond associated with a digging closed off low over Southern California. Given the model agreement on the overall pattern will favor a blended solution as a starting point with a strong lean toward the HRRR and NAM12 for wx details in the near term. Sensible weather will feature clear skies tonight with good radiational cooling thanks to light winds and lower dewpoints. Accordingly, expect a moderate to large ridge to valley temperature difference through the night - peaking at dawn. Additionally, am concerned with some fog forming in the river valleys overnight - frost possible in other areas - into Tuesday morning so have included that in the grids. Tuesday will be a pleasant day with mostly sunny skies through the morning and into the afternoon before high clouds start to increase from the west. With this, temperatures will top out in the low to mid 60s along with increasing south to southwest winds by late afternoon. The approaching low pressure system to the west will bring our dry period to an end into Wednesday morning as it activates increasing moisture over the area pushing showers into eastern Kentucky by dawn while PWS climb to over 1.0 inches again. Upper level divergence, from the right entrance region of a jet streak to the north of the Ohio River, passing over the area early Wednesday morning will enhance the showers into dawn as they move in from west to east. Again used the CONSShort and ShortBlend as the starting point for all the grids through Wednesday morning. Did make some significant terrain based changes to the lows tonight and also some point specific temp adjustments for Tuesday and Tuesday night. As for PoPs, kept it quiet until after 00z Wednesday and then ramped them up a bit quicker than the blend into Wednesday morning - west to east. .LONG TERM...(Wednesday through Monday) Issued at 330 PM EST MON FEB 26 2018 Models in reasonable agreement with the overall pattern across the CONUS through at least the first half of the extended. Mid/upper level flow remains amplified and somewhat progressive through the period. Some differences do show up from time to time but in general they appear minor enough not to significantly effect sensible weather. We begin the extended under the influence of southwest flow. But energy will move out of the southwest CONUS quickly and enter the lower Ohio Valley by Dy4 Thursday. This energy will phase with a short wave trough dropping southeastward out of Canada resulting in a rapidly deepening low over the Mid-West. Thereafter, ridging builds into the Mississippi and Ohio Valley for the remainder of the forecast. Another system does approach from the west at the very end of the forecast window. At the surface, a potent low pressure system will develop over the central plains and deepen rapidly as it tracks into the mid Ohio Valley, again by Dy4, Thursday. High pressure then builds into the region for the weekend, shifting off to the east coast by Monday as our next weather maker just begins to enter the picture from the west by late Monday. Sensible weather features a wet start to the extended. A stout low level jet will pump in higher PWAT air from the out of the Gulf of Mexico, with more moderate to heavier showers breaking out along a developing warm front moving in from the Tennessee valley. Widespread precipitation continues through Thursday as the system deepens over the Ohio Valley. NAM, ECMWF, and Canadian all lay out between 1.5 and 2.5 inches across our southern most counties through Thursday. The GFS is an outlier at this time, putting the axis of heavier rainfall much further south. After coordinating with adjacent offices have decided to issue an ESF for areas generally south of the Hal Rogers Parkway. Southwest winds continue to look pretty strong Thursday veering to the northwest Thursday night before tapering off through the day Friday. Winds appear as strong behind this system, post-frontal Thursday night, as pre-frontal during the day Thursday. As such, will continue to mentioned the threat of gusty winds in the HWO. Precipitation will wind down from west to east Thursday night into Friday morning, with far southeastern Kentucky hanging on the longest as the low levels veer to a favorable northwest downslope flow. Dry weather returns for the weekend under the influence of high pressure. With over 2 weeks of above normal temperatures, seasonably cool temperatures return by the end of the week, with plenty of sunshine to cap off the weekend. Temperatures moderate back up a bit for the start of the following week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 740 PM EST MON FEB 26 2018 With high pressure building into and then moving across the area through the period, VFR with only some high clouds can be expected from time to time. A few deeper valley locations may experience MVFR or IFR vis between 7Z and 13Z, but this is not expected to affect the TAF sites. Winds will be light through the period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM...RAY AVIATION...JP
Area Forecast Discussion
National Weather Service Marquette MI
641 PM EST Mon Feb 26 2018 .SHORT TERM...(This evening through Tuesday) Issued at 410 PM EST MON FEB 26 2018 WV imagery and RAP analysis indicated a mid/upper level trough into the wrn CONUS and a broad ridge through the plains and MS valley resulting in a mild flow of Pacific air into the region. At the surface, sw flow prevailed through the wrn Great Lakes between low pressure north of Lake Winnipeg and a ridge over the Ohio Valley. Otherwise, vis loop showed an area of WAA mid/high clouds sliding through the nrn Great lakes leaving mostly sunny skies. Tonight, Mid-level and sfc ridging will maintain dry conditions. Additional bands of mid/high cloiuds will move through the area. Otherwise, southwest winds will keep low-levels well mixed so that min temps will only drop into the mid to upper 20s. Tuesday, expect increasing clouds as a weak shortwave trough approaches the region. Any pcpn into the srn cwa associated with a band of mid level fgen is expected to hold off until Tue night. Even with the additional clouds, temps will again climb into the low to mid 40s. .LONG TERM...(Tuesday night through Monday) Issued at 326 PM EST MON FEB 26 2018 Overall, quasi-zonal flow across the CONUS will break down and become highly amplified by the end of the week as a slowly progressive trough, ridge, trough pattern develops across the CONUS. Through this week, the weather looks to remain fairly quiet with mild, above average temperatures for this time of year. Precipitation wise we should remain fairly quiet, but do have a few chances through the middle to end of the work week for some light wintry precipitation. Otherwise, high pressure will take over through the end of the work week and much of the weekend, giving way to dry weather. Tuesday night through Wednesday: Light wintry precipitation is possible Tuesday night across the south central and east. Forecast soundings do not show much depth to the moisture and/or temperatures cold enough to support snow. Therefore, precipitation will likely fall as freezing drizzle if the cloud depth is deep enough to support droplet growth, which could allow for impacts to the morning commute on Wednesday. High pressure will then quickly settle into the region during the day on Wednesday and allow cloud cover to gradually diminish. Thursday through Friday: A strengthening surface low will lift northwards towards the Ohio River Valley Thursday as a potent shortwave ejects out of the Plains. Model trends have consistently trended further south with the heavier precipitation associated with this system, which make sense based on the track and orientation of the mid-level trough, along with the drier air being advected southward on the northwest side of the system. Therefore, the only noticeable change we should see is a bit colder temperatures late Thursday through Friday, with a few lingering chances for light wintry precipitation off of Lake Michigan. Right now 850mb temperatures look marginal, so it may even be a stretch to get any ice growth within the lake effect clouds. Upcoming weekend: We will be sandwiched in between systems over the west and east coast this weekend. With upper-level ridging dominating the upper-level pattern, expect a dry weekend as high pressure will linger across the region. Towards the very end of the weekend into early next week, the western most trough will gradually move eastward towards the Great Lakes region and may bring the next best chance for widespread precipitation. However, given the quasi- blocking pattern progged to be in place across the CONUS, wouldn`t be surprised if this system is delayed even further. Regardless, it`s far early to think about any details as the track and speed of this system will highly dictate any impacts. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 641 PM EST MON FEB 26 2018 VFR conditions are expected through the forecast period. LLWS is expected at all sites tonight as SW winds increase above the low level inversion. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 410 PM EST MON FEB 26 2018 Tonight through the end of the week, winds are expected to remain below 25 knots. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...Ritzman AVIATION...Titus MARINE...JLB