Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/18/18


Area Forecast Discussion
National Weather Service Charleston SC
936 PM EDT Wed Oct 17 2018 .SYNOPSIS... A cold front will push south of the region tonight. Cooler high pressure will build over the region Thursday and Friday before shifting offshore Saturday. A stronger cold front will advance through the area Saturday night, followed by cool high pressure through the middle of next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... The cold front was located roughly along a Tybee Island, GA to Glennville, GA line at 18/0130z and moving south. The boundary is on target to push south of McIntosh County early Thursday morning as cool, high pressure wedges south into the region behind it. Any isolated shower activity associate with the front should remain over the Georgia coastal waters over the next few hours within the pre-frontal warm sector. Expect a fairly widespread 3.5-4.0 kft stratocumulus deck to develop by mid-late evening in response to increasing isentropic assent, mainly along the 305K surface. Condensation pressure deficits (CPDs) along this surface are forecast to remain fairly high (>20 hPa), so most of the lift should go to thickening cloud development instead of shower production. Could see a sprinkle or two develop over parts of the Charleston Tri-County area closer to midnight where CPDs drop closer to 10 hPa for a few hours, but think the risk for measurable precipitation is just too low to mention as the mid- levels continue to dry out. Modest post-frontal cold air advection will help drive overnight lows from the mid 50s across far northern parts of Dorchester and Berkeley Counties away the Santee-Cooper lakes to the lower 70s along the Georgia coast where a developing onshore will help moderate temperatures quite a bit. For the late evening update: * Made minor adjustments to wind and wind speeds per latest RAP and H3R output. * Made minor adjustments to dewpoints based upstream trends. The rest of the forecast is on track. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... Thursday: High pressure will provide much cooler conditions as compared with recent days. High temps Thursday will range from the upper 60s/lower 70s north to the lower/mid 70s south. Thursday night, inland low temperatures will range from the upper 40s/lower 50s inland/north to the mid 50s.lower 60s south. NE winds will maintain temperatures in the lower/mid 60s on the beaches. As the high pressure shifts into the Atlantic and a coastal trough develops, a few showers could push onshore into GA coastal counties late. Friday: Expect temps a bit warmer than those of Thursday. Temperatures will be close to normal for mid October, ranging from the lower/mid 70s north to the mid/upper 70s south. Onshore flow interacting with a coastal trough could support a few showers, especially across central/southern coastal counties. Friday night: Low-level flow will turn toward the south/southwest ahead of an approaching cold front. This will hold low temps in the lower/mid 60s inland and around 70F at the coast. Also, guidance suggests that moisture transport will intensify along the coast and adjacent coastal waters, supporting at least isolated/scattered showers. Accordingly, at least slight chance/chance PoPs are in order along the coast and adjacent coastal waters, especially overnight. Saturday: A strong cold front will approach the region. Ahead of the front, early showers are expected to push offshore, then showers/thunderstorms should push into the region during the afternoon. There remains some uncertainty regarding timing/coverage of prefrontal convection, so afternoon PoPs are capped at 40-50 percent. Meanwhile, outside any showers/thunderstorms, WSW winds and compressional heating will help push temps into the lower/mid 80s. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... The cold front and associated showers are expected to cross the region Saturday night. Then, high pressure will provide below-normal temperatures Sunday through early next week, followed by a trend toward near normal temps midweek. As the high shifts offshore, coastal troughing could support occasional showers along the coast next week. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... VFR. Gusty winds will develop later this evening and persist into Thursday morning before diminishing. Extended Aviation Outlook: Mainly VFR. Flight restrictions are possible in showers as a cold front crosses the region Saturday into Saturday night. && .MARINE... Tonight: Post-frontal cold air advection and the associated isallobaric rises will support winds increasing to 20-25 kt with gusts to 30 for much of the waters off the South Carolina coast and 15-20 kt with gusts to 25 kt for the Georgia waters through daybreak. Small Craft Advisories for all coastal legs look well placed and were not changed, although the beginning times may be a few hours too fast. Seas will build in the strengthening northeast flow, peaking 4-6 ft off the Charleston County coast to 2-4 ft off the Georgia coast by daybreak. For Charleston Harbor, winds look a bit too marginal for a Small Craft Advisory with winds peaking 15-20 kt. Could see a few gusts near 25 kt near the harbor entrance, but these should remain fairly infrequent and not enough to justify an advisory at this time. Thursday through Monday night: High pressure will produce elevated northeast winds and elevated seas Thursday into Friday, justifying ongoing Small Craft Advisories outside Charleston Harbor. As high pressure shifts into the Atlantic and a strong cold front approaches the region, winds will turn toward the S/SW Friday night and toward the W/SW Saturday. Winds/seas should remain below SCA thresholds through this period. Then, another cold front will cross the waters Saturday night, followed by high pressure and strong cold air advection. Winds will shift to the north/northwest through Sunday and will veer toward the northwest Sunday night. Elevated winds/seas will likely reach SCA levels in most areas. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory from 2 AM to 11 PM EDT Thursday for AMZ350-352. Small Craft Advisory from 5 AM Thursday to midnight EDT Friday night for AMZ374. Small Craft Advisory from 5 AM Thursday to 5 AM EDT Friday for AMZ354. && $$
Area Forecast Discussion
National Weather Service Hastings NE
645 PM CDT Wed Oct 17 2018 .SHORT TERM...(This evening through Thursday) Issued at 239 PM CDT Wed Oct 17 2018 Aloft: RAP model tropopause analyses show split flow over the CONUS with a ridge over a cut-off low in the W and confluent flow downstream over the E. The cut-off low has induced a shortwave ridge over the Cntrl Plns. This ridge will drift E of the rgn tomorrow as the cut-off low weakens and opens up into a trof that is fcst to extend from ND-WY-UT by 00Z/Fri. This will result in the flow becoming SW. Surface: Abnormally strong 1033 mb high pres was over Neb/KS. A continental polar air mass covered most of the Cntrl/Ern USA. The high will migrate E into the Midwest tonight and in the OH Vly tomorrow. SW flow will strength as a result. Tonight: Clear to start but incrsg mid-lvl clds from the SW as the ridge axis edges E. Used cross sections to time the leading edge of the clds. Lows primarily 40-43F except colder in the Loup Rvr Vlys. Thu: Partly-mostly cldy as mid-lvl clds cont to advance across the entire CWA. Highs should still be in the 60s...but coolest (around 60F) S and W of the Tri-Cities. Some sprinkles will be possible mainly after noon. There might even be enough to wet the roads S of KS Hwy 24. Becoming brzy. By midday SW winds will be 15-20 kt with G25-30 kt. .LONG TERM...(Thursday night through Wednesday) Issued at 239 PM CDT Wed Oct 17 2018 Aloft: The current longwave pattern (described above) will remain in place...but will show signs of progression and possibly deamplification mid-late next wk. The shortwave trof just NW of the CWA Thu eve will cross the rgn Fri. NW flow will prevail over the Plns Sat-Mon with a shortwave ridge moving in late Mon. Spread among the last 2 runs of global models increases next Tue-Wed regarding the trof that comes out of the Desert SW into the Plns...but the 00Z EC ensemble mean looks similar. So it appears the ridge will move E Tue night with the trof moving in Wed. Surface: The next Canadian cool front will be dipping into the Nrn Plns Thu night. It will sweep thru here Fri with little more than a wind shift and an increase in winds. Strong but quick- moving 1030+ high pres will drop out of Canada into the Plns Fri night into Sat. The next low will advance thru cntrl Canada Sun and this will drive a warm front thru here. The associated cool front will quickly move thru behind it Mon. A big Canadian high will then build in as it slides into the GtLks Tue-Wed. Temps: Overall should average near normal. Near 70 Fri which is currently looking like the warmest day of the next 7. A brief intrusion of cool Sat (50s)...back to the 60s Sun-Mon...then down to the 50s again Tue-Wed. Precip: Some sprinkles could linger into Thu eve. Otherwise dry until next Tue night or Wed. That system that will come out of the Desert SW is not looking very wet. The +RA will be over the Srn Plns with lighter rain possible up here. Potentially hazardous wx: None. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Thursday) Issued at 635 PM CDT Wed Oct 17 2018 Surface high pressure will continue to slide to the southeast as an upper level disturbance across the southwest lifts northeastward towards the plains. A tightening pressure gradient is anticipated ahead of this system...with wind gusts of 25 to 30 mph expected tomorrow afternoon. Conditions overall will remain VFR...although increasing high cloud are expected overnight...with CIGS lowering to around 12KFT tomorrow afternoon. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ SHORT TERM...Kelley LONG TERM...Kelley AVIATION...Rossi
Area Forecast Discussion
National Weather Service Goodland KS
1000 PM MDT Wed Oct 17 2018 .SHORT TERM...(This evening through Thursday) Issued at 327 PM MDT Wed Oct 17 2018 Latest upper air analysis shows the closed low over the Four Corners Region. Rounding the closed low was a plume of higher water vapor concentration extending north to the KS/OK border. Isolated showers were moving north in the higher moisture plume. Northeast of the closed low a long wave trough continued over the Eastern CONUS. Tonight the showers will continue to move north toward the forecast area. Most of the stronger lift will be south of the forecast area. However isolated showers may move into the forecast area after midnight. Thursday morning the plume of moisture and showers will continue to drift north over Kansas. The best isentropic lift will occur during the latter half of the morning, into the early afternoon before the drier air pushes the showers east of the forecast area. Confidence for any rain development is on the low side due to the somewhat scattered lift moving over the forecast area. A low level jet will develop over the forecast area. Winds from this feature will mix down to the ground, causing wind gusts to range from 30-40 MPH. .LONG TERM...(Thursday night through Wednesday) Issued at 327 PM MDT Wed Oct 17 2018 Most of this period will be dry except for the next chance for rain mid week next week. A couple weak cold fronts will move through the forecast area Friday through Monday as the closed low over the Desert Southwest becomes absorbed in the long wave trough. These frontal passages will cause the highs to vary each day by as much as 10 degrees. Due to the subsidence and drier air with the trough axis overhead, am not expecting any clouds to form during this time despite the frontal passages. Toward mid week an upper level short wave ridge will move over the Plains. Behind it a short wave trough will move through, giving the forecast area a chance for rainfall. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1000 PM MDT Wed Oct 17 2018 A weather disturbance with good moisture in the 850-500mb layer originating along the Texas/New Mexico border late this evening is forecast to forecast to move northeast reaching the KGLD terminal in the 18z-21z timeframe and the KMCK terminal in the 20z-23z timeframe producing a few rain showers over/near the terminals. After 00z the weather disturbance moves away from the terminals. The NAM and 00z HRRR do show sub vfr stratus developing around the KGLD terminal after about 02z so have added that to the forecast. South winds below 11kts expected at both terminals through about 13z before quickly increasing from the south at KGLD by 14z and KMCK around 17z. Peak gusts around 35kts possible. Winds subside and fall below 12kts in the 01z (KMCK) to 05z (KGLD) timeframe. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JTL LONG TERM...JTL AVIATION...99
Area Forecast Discussion
National Weather Service Louisville KY
910 PM EDT Wed Oct 17 2018 .Forecast Update... Issued at 910 PM EDT Wed Oct 17 2018 Upper disturbance over the Red River Valley has spread a respectable cirrus shield ahead of it into the Ohio Valley. This maintains plenty of bust potential in our min temp forecast overnight, and therefore the Frost Advisory that is already flying. None of the synoptic models seem to handle these clouds well, and much of the hi-res guidance is also struggling. Only the HRRR seems to be on board, and it actually has skies clearing out again just before daybreak. Will not change the min temp forecast, but have adjusted the hourly trends for a slower drop in temps most of the night, while still maintaining a narrow window around daybreak for frost formation. If anything it will be lighter and more patchy than advertised, but it remains a good bet in any of the typical cold spots such as sheltered valleys. Fog potential already limited to river valleys, and that is still on track. && .Short Term...(This evening through Thursday) Issued at 230 PM EDT Wed Oct 17 2018 ...FROST ADVISORY TONIGHT AND EARLY THURSDAY MORNING... Still have the same concerns on bust potential for the frost as the previous forecast. Typically the first night after a cold frontal passage is too mixy for that frost to form. Also, an upper wave bringing a narrow band of high clouds is forecast to move out of the Red River valley into KY late tonight. All that said, the frost tool we use, which takes into account wind and sky cover, still is going for widespread frost along and north of a line from HNB to Etown to Liberty, with areas of frost...the next category down in coverage... forecast down close to the TN border. Briefly considered cancelling part of the advisory close to the TN border, but given statistical guidance calling for mid 30s at BWG, the chance still is there. The other potential is for fog development along river valleys, as steam fog develops with air/water temperature differences of around 25 degrees or greater. That wave of clouds will be through the region by late morning, so the rest of Thursday looks great, though chilly, with highs 10-15 degrees below normal. .Long Term...(Thursday night through Wednesday) Issued at 233 PM EDT Wed Oct 17 2018 Thursday night the center of the cold surface high that brought frost to portions of the region in the short term will move off to Virginia, allowing temperatures Thursday night to be a couple of degrees warmer than Wednesday night. Readings will bottom out in the mid 30s, so some patchy frost will still be possible. Friday clouds will increase from west to east over the course of the day as a cold front approaches. Rain chances will increase dramatically by evening with most folks receiving precipitation Friday night. The system will then pull off to the east on Saturday, with wrap around clouds and possibly some patchy sprinkles or drizzle lingering. In our position between the storm system to our east and a strong Canadian high over the Northern Plains, Saturday will be rather breezy with gusts of 20-25mph possible. That strong high to our west will slide across the Ohio Valley Sunday and Monday with some very chilly air. With the center of the cold dome to our west Sunday morning and our east Monday morning we won`t have ideal conditions here for a freeze, but frost still looks like a good bet Monday morning and possibly Sunday morning. Monday night/Tuesday a cold front will come at us from the northwest but it will be falling apart and not associated with any precipitation (though there will be an increase in upper clouds). Then the next Canadian high will push into the Great Lakes and give us more dry and cool weather mid week. && .Aviation...(00Z TAF Issuance) Issued at 650 PM EDT Wed Oct 17 2018 Decent post-frontal NW wind surge is ongoing, but should lay down after sunset. Expect light north winds overnight, picking up out of the NE Thu morning but remaining less than 10 kt. Otherwise look for VFR through the TAF period, with cirrus from a southern Plains disturbance not expected to be enough for a ceiling. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...Frost Advisory from 2 AM EDT /1 AM CDT/ to 10 AM EDT /9 AM CDT/ Thursday for INZ076>079-083-084-089>092. KY...Frost Advisory from 2 AM EDT /1 AM CDT/ to 10 AM EDT /9 AM CDT/ Thursday for KYZ023>043-045>049-053>057-061>067-070>078-081- 082. && $$ Update...RAS Short Term...RJS Long Term...13 Aviation...RAS
Area Forecast Discussion
National Weather Service Miami FL
817 PM EDT Wed Oct 17 2018 .UPDATE... Radar is currently quiet with a stray shower or two over the Atlantic ocean pushing westward. Easterly winds at 5 to 10 mph are indicated by the latest observations along the east coast beaches with light and variable winds elsewhere. Meso-scale guidance, including the HRRR and Hi-Res WRF, prog isolated showers to develop along Broward and southeast Palm Beach counties overnight. Therefore, increases PoP coverage over portions of the east coast metro to account for this. Otherwise, all other variables looked on track. && .PREV DISCUSSION... /issued 733 PM EDT Wed Oct 17 2018/ AVIATION... Rain chances remain very low for tonight with VFR prevailing through the next 24 hours. The breezy easterly to southeasterly flow should resume on Thursday afternoon with speeds around 12-13kt. PREV DISCUSSION... /issued 404 PM EDT Wed Oct 17 2018/ DISCUSSION... SHORT TERM: Latest GOES16 WV imagery showed deep mid-level ridging over the Southeastern CONUS. Clockwise flow around this feature has allowed for persistent breezy east winds across the Southern portions of Florida. Satellite derived PWATS indicate less than exceptional values at 1.5". Shower activity has been minimal today as mostly dry conditions have prevailed. Through this evening, the HRRR and Hi-res WRF guidance depict shower development in western Collier counties then have them diminishing after sundown with the loss of diurnal heating. Breezy easterly winds are forecast along the east coast beaches tonight with light and variable winds elsewhere. Easterly flow and shallow moisture will allow for the development of isolated showers along the eastern third of the peninsula. Minimum temperatures are expected to be near 80 along the east coast metro areas, values up to 5 degrees above normal for this time of year, and mid-70s elsewhere. LONG TERM: At least subtle changes continue to be hinted at by global guidance for the weekend and early next week. Upper-ridge should weaken and drift southeastward, allowing some influence in South Florida from mid-latitude longwave trough that will progress through the eastern CONUS this weekend. A weakening cold front is forecast to approach central Florida Friday night into Saturday, then be reinforced by another weak front that appears poised to reach South Florida later Sunday into Monday. Although both GFS and ECMWF show the front having little dynamical support or significant moisture pooling for more than scattered convection, they differ in the magnitude of any cooler (i.e. drier) air behind the front. ECMWF suggests a slightly more pronounced FROPA, with early next week yielding dewpoint values in the 60s and temperatures down toward normal. GFS has front stalling over far southern Florida will little in the way of drier air and only lower temperatures to result from curbed diurnal heating from clouds/scattered showers. MARINE... With high pressure dominating the South Florida waters, moderate east wind will prevail into the weekend with only isolated showers and thunderstorms. At times, wind speeds may reach 15 kts and small craft should exercise caution, particularly overnight in the Atlantic. AVIATION... Isolated Atlantic showers could produce MVFR cigs briefly this afternoon. Some convection later in the afternoon and evening could affect APF. Rain chances are not quite high enough to include any other restrictions at this time. The breezy easterly to southeasterly flow should continue with some easing during the overnights. BEACH FORECAST... East wind of 15 to 20 mph has persisted for several days and will continue for several more. This has increasingly favored rip current generation along the east coast and there is now a High Risk of Rip Currents on Atlantic beaches today. A moderate to high risk will likely continue on the east coast into the weekend. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 77 88 77 87 / 20 20 20 20 Fort Lauderdale 80 88 79 87 / 30 20 20 20 Miami 78 88 77 87 / 20 20 20 20 Naples 74 90 73 90 / 10 30 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && UPDATE...11/HVN DISCUSSION...11/HVN MARINE...11/HVN AVIATION...17/AR BEACH FORECAST...11/HVN
Area Forecast Discussion
National Weather Service Springfield MO
623 PM CDT Wed Oct 17 2018 ...Updated for 00Z Aviation Discussion... .SHORT TERM...(This evening through Thursday) Issued at 229 PM CDT Wed Oct 17 2018 Temperatures have warmed up nicely into middle to upper 60s this afternoon given a dry airmass in place. High pressure over Iowa was providing a steady north wind this afternoon. Extensive cirrus was spreading northeast into the area from the south and this will be key in regards to overnight low temps and frost potential. Forecast soundings from the RAP and NAM overnight show that the cirrus/high cloud cover should encompass at least the southern half of the area overnight. This will keep low temps from falling to their max potential. Low temps generally range from the middle 30s in the VIH area to around 40 across the BBG and JLN areas. Do think there will still be some frost potential in the eastern ozarks therefore the Frost Advisory remains in effect out there however did trim back counties on the western edge where it appears there will just be too much cloud cover to promote widespread frost. Thursday looks to be similar to today with perhaps a little more high cloudcover keeping temps from reaching as high as today. .LONG TERM...(Thursday Night through Wednesday) Issued at 229 PM CDT Wed Oct 17 2018 Shortwave energy approaches from the southwest late Thursday night into Friday with increasing rain showers as that system moves through on Friday. Forecast soundings indicate little if any instability at this time therefore will be keeping thunder chances out of the forecast. Rainfall amounts look light with the majority of the rainfall south of Interstate 44. A strong cold front moves through late Friday night and will bring a reinforcing shot of cool air to the region for the weekend. Low temperatures Sunday morning look to drop into the lower 30s as high pressure moves overhead. Widespread frost and perhaps a light freeze may occur during this time. Rather quiet/benign weather is then expected until the middle of next week when additional disturbances approach from the southwest to provide rain chances. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 623 PM CDT Wed Oct 17 2018 VFR flight conditions are expected across the area through the TAF period. Only high level clouds expected with northeast winds becoming more east northeast Thursday afternoon at less than 12 knots. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...Frost Advisory from 1 AM to 9 AM CDT Thursday for MOZ057-058-070- 071-082-083-098. KS...NONE. && $$ SHORT TERM...Burchfield LONG TERM...Burchfield AVIATION...Raberding