Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/26/18

Area Forecast Discussion
National Weather Service Albuquerque NM
632 PM MDT Wed Apr 25 2018 .PREV DISCUSSION...530 PM MDT Wed Apr 25 2018... .AVIATION... 00Z TAF CYCLE Dry northwest flow aloft will maintain VFR conditions across the region over the next 24 hours. Winds will be light and terrain driven tonight. West to northwest winds will increase during the late morning and early afternoon Thursday across western and central NM with gusts of 15 to 20 knots. A backdoor cold front will move into far northeast NM around 12Z Thursday and into east central NM between 15Z and 17Z, reaching KROW around 19Z. Winds behind the front will be from the north to northeast 10 to 20 knots with gusts to around 25 knots. 28 && .PREV DISCUSSION...330 PM MDT Wed Apr 25 2018... .SYNOPSIS... Areas of smoke will continue to impact Catron County including Glenwood and Reserve tonight and Thursday as northwest flow steers the smoke from Arizona`s Rattlesnake Fire over that area. A windy cold front will dive southwestward through the eastern plains on Thursday with gusts around 50 mph across northeast areas, and a slight chance of thunderstorms along the east slopes of the Sangre de Cristo Mountains. An upper level low pressure system slowly crossing the northern and central Rockies will draw moisture northwestward over New Mexico this weekend. Showers and thunderstorms will impact western areas Friday, before spreading to include central areas Saturday, then shifting eastward across the eastern plains Saturday night and Sunday. Breezy to windy conditions are expected on Sunday as drier air wraps into the system and over New Mexico from the southwest. A secondary upper level trough deepening over the Great Basin will steer the jet stream over the state on Monday with even stronger winds. && .DISCUSSION... Residents in the Glenwood, Mogollon and Reserve area reported hazy skies and the smell of smoke this afternoon. The smoke plume from the Rattlesnake Fire is evident on satellite imagery crossing that area. The HRRR Model`s Near-Surface Smoke product shows light to moderate concentrations tracking over central and southwest Catron County from the northwest tonight and Thursday ( An upper level trough will clip NE NM in NW flow aloft on Thursday. It may trigger a few showers and thunderstorms along the east slopes of the central mountain chain, especially around Raton Pass, but the greater impact will be the windy cold front that it will send southwestward into the state. Northeast wind gusts to 40 mph will be common across the eastern plains on Thursday, except for gusts near 50 mph across the northeast highlands and plains along and east of I-25. A moist low level south southeasterly return flow will be drawn into the state Thursday night and Friday, with a mix of wet and dry thunderstorms breaking out across western areas on Friday afternoon in response to the aforementioned upper low over the Great Basin. Models vary on how robust the moisture surge will be, with the GFS on the wet side and the NAM and ECMWF on the drier side. The drier NAM handled a similar moisture surge better than the GFS and ECMWF last week, so this forecast package sides with the NAMs POPs and coverage of precipitation moreso than the GFS for this weekend. If the NAM is right again, our POPS could be a little too high. 44 && .FIRE WEATHER... A slightly more active weather pattern through the weekend will hold off critical fire weather conditions for most areas until Sunday. Winds will turn southerly tonight with very good humidity recoveries for eastern NM and fair values across the west. Another back door cold front will shift southwest through eastern NM Thursday with a reinforcing shot of low level moisture westward, strong north winds, and slightly below normal high temperatures. Widespread excellent ventilation is expected. The front will move west through gaps in the central mt chain Thursday night with another blast of canyon winds. Moisture is expected to make it farther into western NM behind the next front through Friday. A weak shortwave ridge approaching from the west Friday will allow some mid and upper level moisture to slide north from Mexico during the afternoon. This will help fire up a couple wet/dry showers along the Cont Dvd by late day. A few dry lightning strikes are possible. Meanwhile, the remainder of the area will remain near to slightly below normal with higher min humidity and fair to good ventilation Friday. A large upper level storm system is still shown by models to take shape over the Great Basin over the weekend and allow increasing south to southwest flow over NM. This will help advect even deeper moisture northward and set the stage for a potentially more active day of showers and storms Saturday within central and western NM. Moisture levels appear favorable for larger wetting rainfall footprints along with gusty outflow winds. Ventilation will improve to excellent all areas. The base of the upper trough will move into northern AZ Sunday and spread much drier and windy conditions in western NM. Critical fire weather conditions will be possible along and west of the Cont Dvd by late afternoon. This may be problematic if any lightning strikes hit the wrong area with little wetting rainfall. Meanwhile, the east will see more showers and storms with severe weather possible. The base of the upper trough doesn`t move much Monday and Tuesday with widespread stronger southwest winds and very dry air sliding over NM. This will increase potential for critical fire weather for nearly the entire area. Guyer && .ABQ WATCHES/WARNINGS/ADVISORIES... Wind Advisory from 8 AM to 3 PM MDT Thursday for the following zones... NMZ527-528-530-531. && $$
Area Forecast Discussion
National Weather Service Boston/Norton MA
1042 PM EDT Wed Apr 25 2018 .SYNOPSIS... Low pressure will push northeast from the mid Atlantic coast, crossing the region overnight. This will bring locally heavy downpours may result in some brief poor drainage street flooding and possibly an isolated thunderstorm or two. Seasonably mild temperatures will follow for the remainder of the week with mainly dry weather other than a period of showers Friday. A cool down will occur Saturday night and Sunday, but this will be short lived as unseasonably warm temperatures are in store for the region by the middle of next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 1015 PM Update... Area of SHRA/+SHRA moving across central and northern areas this evening. May see an embedded brief thunderstorm as it moves N-NE across NE and N central Mass through around midnight or so. Noting another area of showers E of the central NJ coast on latest NE regional 88D radar imagery. Spotty C/G lightning seen with this areas, so could see isold thunder with this. As the heavier showers shift NE, may see leftover light showers or even drizzle with low level moisture in place. Still noting some patchy dense fog along the RI S coast, though visibilities have been between 1/4 and 1/2 mile. Also starting to lower across S coastal Mass, will monitor this for possible Dense Fog Advisories there. S-SE winds have been diminishing, but still noting some gusts up to 20-25 kt. Will continue to see downward trend as the low level jet moves offshore. Previous Discussion... Convective showers with locally heavy rain continue to lift north across eastern half of New England. Activity is located along the nose of the low level jet. As the axis of the low level jet shifts to the east, main focus for heavy rain will gradually shift offshore after midnight. Main impact will be localized nuisance poor drainage street flooding in areas of heavy rain. Another concern for tonight is dense fog as some mid level drying moves in tonight while low levels remain saturated. Low vsbys have developed over southern RI where we will issue a dense fog advisory through tonight. Plenty of low level moisture present and advisory may need to be expanded along the rest of the south coast. As the upper level low rotates through, the mid and upper levels begin to saturated and there could be a redevelopment in strong showers moving through SNE. Best timing is between 03Z and 09Z as strong mid-level omega pushes through. The east coast of MA has the best shot of seeing the strong downpours. Still cannot rule out the thunder potential as RAP data has several hundred joules of MUCape and Showalters dropping below 0C. Heavy rainfall will be the main threat as well as gusty winds, especially along the passing cold front. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... Thursday... Upper level low will begin to pivot out of the region during the day on Thursday. Still some lingering moisture in the mid-levels with steep lapse rates which will yield to sct showers in the morning. Deep layer moisture will push northward towards Maine resulting in low precip chances by the afternoon hours. Still expect sct to broken clouds but overall trend will be dry by sunset. Gusty WNW flow expected along as the mid level shortwave passes through. Steep lapse rates and downsloping flow will result in good mixing to near 850mb. Expect wind gusts to near 25-30 MPH by the afternoon as highs reach into the mid to upper 60s. Overall a pleasant Spring day. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... Highlights... * A period of showers Fri afternoon/evening * Scattered showers Sat, mainly interior * Dry and cooler Sun then seasonably mild Mon * Dry with a significant warming trend Tue/Wed Friday... Southern stream shortwave will be lifting northward into SNE during the afternoon/evening. Shortwave is deamplifying but modest low level jet and PWAT plume will bring a period of showers to much of SNE, especially afternoon into early evening. There may be a focus for brief heavy showers and an isold t-storm across RI and SE MA where some elevated instability is present along the nose of the low level jet. Highs will range from the upper 50s to lower 60s. Saturday... Next mid level shortwave and cold front approaches from the west. This will lead to an increasing risk of sct showers, mainly across central/western MA and northern CT during the afternoon. Otherwise, expect pt-mosunny skies in the coastal plain with increasing afternoon clouds in western New Eng. There is a low risk a few showers could move into eastern New Eng Sat night as the front moves through. With pre-frontal SW flow, milder temps expected Sat, reaching mid 60s to near 70, except cooler along the south coast. Sunday... Cooler post-frontal airmass as deep trough settles over the northeast and 850 mb temps cool to around -4C. Temps will remain mostly in the 50s, with a few locations topping out near 60 in RI and eastern MA. Chilly night Sun night with lows in the 30s but close to 30 across the typical colder locations. Frost headlines may be needed where growing season has started, with greatest risk across northern CT. Monday through Wednesday... A pattern change will occur next week as deep trough lifts out Mon and is replaced by building heights and mid level ridging through the middle of the week. Monday will be the transition day with seasonably mild temps after a cold start to the day. Then warming mid level temps will result in temps reaching into the 70s Tue with potential for some lower 80s Wed. But SW flow will result in cooler temps along the south coast. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Thursday/...Moderate to High confidence. Overnight...IFR-LIFR conditions. Showers with locally heavy rain through this evening and can`t rule out an isold t-storm through 05Z across E Mass/RI/NE CT terminals. Low CIGS and areas of fog will linger across the terminals much of the night. Thursday...Improving conditions to VFR with mix of MVFR north of the Pike during the day. Gusty westerly winds between 20-30 kts by the afternoon. KBOS Terminal...Moderate confidence in TAF. IFR conditions in rain and lower ceilings through the evening push. Low risk for TSRA through 05Z. KBDL Terminal...Moderate confidence in TAF. IFR conditions in rain and lower ceilings through the evening push. Dense fog is possible during the overnight. Outlook /Thursday Night through Monday/...Moderate to High Thursday Night: VFR. Breezy. Friday: MVFR/IFR conditions possible. Breezy. SHRA likely. Friday Night: MVFR/IFR conditions possible. Breezy. Chance SHRA. Saturday: Mainly VFR, with local MVFR possible. Slight chance SHRA. Saturday Night: Mainly VFR, with local MVFR possible. Sunday through Sunday Night: VFR. Breezy. Monday: VFR. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Thursday/... Overnight...Moderate confidence. Small Craft Advisories for all waters except Boston Harbor. Expect E-SE winds gusting up to 30 kt. Low risk for a few 35 knot gusts early in the evening across the southeast waters. Rough seas up to 10 to 12 ft. Rain showers, heavy at times along with areas of fog and isolated thunderstorms. Visibility locally below 1 nm at times across the southern waters. Thursday...Moderate to high confidence. Small craft conditions continue as winds shift to W, though winds diminish during the day. May see gusts up to 25-30 kt through midday. Seas remain at 5 feet or greater through the day across the open waters as well as the south bays and sounds. Outlook /Thursday Night through Monday/...Moderate to High Thursday Night: Winds less than 25 kt. Rough seas up to 9 ft. Friday: Winds less than 25 kt. Seas up to 5 ft. Rain showers likely. Friday Night: Winds less than 25 kt. Areas of rough seas. Chance of rain showers. Saturday through Sunday Night: Winds less than 25 kt. Seas up to 5 ft. Monday: Winds less than 25 kt. Areas of seas approaching 5 ft. && .EQUIPMENT... The NOAA Weather Radio transmitter serving Providence is out of service due to phone line problems. The phone company has prioritized the issues and is working to get the weather broadcast back on the air as soon as possible. The transmitter serving Hyannis is back in service. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...Dense Fog Advisory until 8 AM EDT Thursday for RIZ006>008. MARINE...Small Craft Advisory until 8 PM EDT Thursday for ANZ232>234- 251. Small Craft Advisory until 3 AM EDT Thursday for ANZ231. Small Craft Advisory until 11 AM EDT Thursday for ANZ236. Small Craft Advisory until 8 AM EDT Friday for ANZ235-237-250- 254>256. && $$ SYNOPSIS...KJC/Dunten NEAR TERM...KJC/EVT SHORT TERM...Dunten LONG TERM...KJC AVIATION...KJC/Dunten/EVT MARINE...KJC/Dunten/EVT EQUIPMENT...Staff
Area Forecast Discussion
National Weather Service State College PA
1009 PM EDT Wed Apr 25 2018 .SYNOPSIS... A weak storm system will continue to move up along the NJ coast and into New England overnight. High pressure will move in for tonight and Thursday before another weak low begins to affect the region Friday into Saturday. A stretch of fair, mild and dry weather will start Sunday as high pressure builds into the forecast area. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Disorganized showers cover portions of the forecast area, with a thin line of the most developed showers just moving through Schuylkill County as of 10PM. Further west we have just some lighter showers or sprinkles. The upper trough is moving into my western zones and the the HRRR shows the showers continuing to dry up as the support weakens. The upper level system will pass by to the NE by tomorrow morning allowing drier air to make inroads from the west. The mostly cloudy skies will will keep minimum temperatures around normal. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... Skies will begin cloudy tomorrow and slowly improve as the day continues. Northwesterly flow will keep winds gusty through the first half of the afternoon with gusts in the 15 to 25 mph possible. Weak high pressure will build into the region through the latter half of tomorrow which will bring clearing skies Thursday night into Friday. Temperatures Thursday will be slightly below normal due to cold air advection due to FROPA and the brisk northwesterly flow. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... Will be tracking a weather system moving through the area Thu night and Friday raising pops. This is ahead of the next trough that will be over the area for the weekend. Will keep pops in the forecast through Saturday when surface pressure rises and drier air moves in for the second half of the weekend. This is all ahead of a rising heights and more ridging setting up for the region. Look for temperatures finally rising above average and real spring weather arriving next week with many areas finally seeing a substantial greenup. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... 1003 mb surface low was located just to the northwest of KACY at 00Z Thu and moving NNE. The departure of this low combined with a cold front pushing east from the Western Mtns of PA this evening will lead to mainly VFR conditions across the Susquehanna Valley, MVFR conditions over the Central Mtns, and IFR with ocnl LIFR over the NW Mtns and Laurel Highlands of PA (KJST and KBFD). Descending portion of a 60 kt mid-level jet wrapping into a compact center of low pressure aloft (near KBUF) will transport some moderately gusty NW winds to the surface overnight and Thur morning. Sustained winds should be in the 12-16kt range and gusts capped at 23-25kts beginning in the west early this evening, and across the Susq Valley around or after midnight. The moderately gusty northwest wind will continue through at least early Thursday afternoon, before diminishing quickly late in the day. VFR will prevail over the Susq Valley late tonight and Thursday, and become the dominant flying conditions across the Western Mtns by late Thu morning. Outlook... Thu...AM low cigs possible W Mtns. Mainly VFR elsewhere early, then widespread VFR in the afternoon. Fri...Areas of rain with low cigs etc. Sat...AM showers/cig reductions possible NW Mtns. Sun...Reductions possible NW Mtns. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo/La Corte NEAR TERM...La Corte/Ceru SHORT TERM...Ceru LONG TERM...Ross AVIATION...Lambert/Ceru
Please see the 00Z aviation forecast discussion below.

AVIATION... An area of rain along with a few embedded thunderstorms continues along the I-35 corridor early this evening. We will mention prevailing light rain along with VCTS for the I-35 sites for the next 1-2 hours. Rain will then shift east of the I-35 corridor, leaving plenty of cloud cover in it`s wake. As of now, it appears cloud bases will be just above MVFR. Clouds will clear from north to south tomorrow as winds generally remain from the north or light and variable. Late in the period, mainly high clouds are anticipated as winds transition to a more southeasterly direction. For DRT, low clouds with bases just above MVFR are in store overnight. We expect a slow clearing trend through the morning hours as winds become light and variable. Southeast winds should return by early evening. PREV DISCUSSION... /ISSUED 235 PM CDT Wed Apr 25 2018/ SHORT TERM (Tonight through Thursday Night)... As of 2PM this afternoon, a multi-cell cluster of storms was pushing eastward along the southern Edwards Plateau into the Hill Country. These storms have been mainly riding the cold front as it pushes slowly southward and interacting with 2000+ j/kg of MLCAPE and favorable 925-850mb moisture flux convergence. A special 18Z KDRT sounding launched just ahead of the cold front shows limited elevated instability behind the front thus expect the weaker elevated convection well behind the cell cluster to remain rather benign other than some occasional CG strikes. Latest HRRR brings this cluster across Bexar county between 4-7 PM with the front and then favoring the southern third of the CWA after 00Z. Extrapolating this motion through 06Z, the majority, if not all of the precip should be clear of the CWA with predominantly north winds taking over, initially 10-15 mph but then weakening to 5-10 towards tomorrow morning. Morning lows tomorrow will be cooler, ranging from the mid to upper 40s in the Hill Country and Plateau and mid to upper 50s in areas south. Thursday expected to be quite a pleasant day with mostly clear skies by the afternoon and highs in the mid to upper 70s. Winds should be light and variable as surface high pressure sets over the area. LONG TERM (Friday through Wednesday)... The main closed low responsible for today`s activity will continue to swing east into the southeast CONUS leaving Texas under a temporary ridge axis before a weak shortwave moves over Friday. GFS/ECMWF keep this passage dry with a weak cold front that stalls along our northern border with SJT. Moving into the weekend, a textbook omega block pattern sets up by Sunday morning with a large ridge over the central US and two closed lows in the Pacific Northwest and over New England. This will shift east by early next week and bring back PoP chances to the area and southwest flow returns and low level moisture flux returns to the region. By mid-week, the aforementioned Pacific NW low will be replaced by a deep trough axis over the Rockies and will likely be influenced by multiple embedded shortwaves from Tuesday through the rest of the week. GFS/ECMWF both highlight Thursday as a cold front quickly pushes south into the area. PREV DISCUSSION... /ISSUED 1235 PM CDT Wed Apr 25 2018/ AVIATION... /18Z TAFS/ A cold front is now affecting the southern Edwards Plateau. The frontal boundary is forecast to push to the southeast this afternoon and affect much of the area, specially the I-35 terminals from 20Z through 23Z. Have included TEMPO groups for all area sites to account for the potential of TSRA. Once the cold front moves across/wind shift takes place, northwest to north winds of 10 to 15 knots are expected with gusts up to 20 knots early this evening. There is a chance for cigs to go down to MVFR conditions during heaviest storms and for much of the overnight hours for KSSF. Austin area airports should remain VFR after the passage of the front. PREV DISCUSSION... /ISSUED 932 AM CDT Wed Apr 25 2018/ MORNING UPDATE... The latest SPC Day 1 Convective Outlook has expanded the marginal risk for severe storms farther northeast which now includes San Antonio. RAP/HRRR trends indicate increasing SBCAPE along the Rio Grande Plains and especially on the Mexican side of the border where 3500+ j/kg have been advertised. Additionally, the 12Z KDRT sounding shows steep mid level lapse rates and favorable low level moisture flux convergence into the southward moving cold front. Effective shear values of up to 50 kts will also help to maintain updrafts as they get going along the front. Latest HREF/TTU-WRF continue to favor the Rio Grande Plains this afternoon and produce a somewhat linear complex of multi-cell clusters beginning at or shortly after 18Z out west. Given the aforementioned parameters, there will be increased potential for hail up to quarter size and strong straight line winds as the cold front continues south throughout the day. PREV DISCUSSION... /ISSUED 633 AM CDT Wed Apr 25 2018/ AVIATION... MVFR ceilings are encroaching SSF and should be at DRT shortly. Think most of the other sites will remain VFR this morning, but MVFR could side swipe SAT later. The cold front will move through the area early this afternoon, shifting winds to the north with speeds around 15 knots. Latest runs of the high-res models have shifted the precip east a bit and actually leave DRT mostly dry. The ultimate areas of rainfall will be highly dependent on where activity develops and will mention VCTS at all sites this afternoon but expect future fine tuning to prevail thunder at some sites when it becomes apparent where this will be. Dry air will slowly filter in after 00z with clearing skies expected overnight. PREV DISCUSSION... /ISSUED 607 AM CDT Wed Apr 25 2018/ UPDATE... Patchy fog is spreading into our southeastern counties. We have updated to include patchy fog this morning in the region. PREV DISCUSSION... /ISSUED 338 AM CDT Wed Apr 25 2018/ SHORT TERM (Today through Thursday)... Upper air analysis last evening showed a trough over the southeastern US and a ridge over the west with northwesterly flow across Texas. At the surface, a front was stretched across Texas north of our CWA from Texarkana to Denton to San Angelo to Midland. Ahead of the front winds were from the southeast across our forecast area. During this period an upper level low will move out of the Central Plains to the lower Mississippi River Valley bringing the frontal boundary through our CWA. The front should be through our area by this evening and move away overnight. This system will bring chances for showers and thunderstorms with the best chance across the western half of the area. Some strong storms could form over the mountains in Mexico and move across the Rio Grande this afternoon and evening. These storms could produce large hail and strong winds. SPC has this area in a marginal risk for severe thunderstorms. A chance for rain will linger tonight, but then drier air will move in on northerly winds Thursday. Temperatures will also be down a few degrees Thursday. LONG TERM (Thursday Night through Tuesday)... The upper level flow will remain northwesterly through Friday. Another weak front will move through Friday, but there won`t be much return moisture between the two fronts. So, this second front will likely move through dry. The upper level flow will be essentially zonal over the weekend and the weather will be dry. Models show activity developing along the dryline Monday and Tuesday with chances for thunderstorms moving across our CWA both days. Given model performance over the past few weeks, we have reduced model POPs for this period since we don`t have much confidence at that time period. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 88 51 80 56 80 / 30 10 0 0 0 Austin Bergstrom Intl Airport 84 51 79 53 79 / 30 10 0 0 0 New Braunfels Muni Airport 84 53 79 53 80 / 70 10 0 0 0 Burnet Muni Airport 79 47 78 52 77 / 20 10 0 0 0 Del Rio Intl Airport 73 54 82 59 81 / 90 10 0 10 10 Georgetown Muni Airport 82 48 79 51 78 / 20 10 0 0 0 Hondo Muni Airport 79 53 79 55 81 / 100 10 0 - 0 San Marcos Muni Airport 87 52 79 53 80 / 50 10 0 0 0 La Grange - Fayette Regional 84 54 76 53 79 / 20 20 - 0 0 San Antonio Intl Airport 84 54 78 56 80 / 90 10 0 0 0 Stinson Muni Airport 84 56 78 57 80 / 90 10 - 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Mesoscale/Aviation...24 Synoptic/Grids...Treadway
Area Forecast Discussion
National Weather Service Wilmington OH
934 PM EDT Wed Apr 25 2018 .SYNOPSIS... High pressure building across the Great Lakes will keep dry weather conditions over the area tonight through Thursday. A weak cold front may bring few showers on Friday. High pressure and drier air are forecast to return on Saturday and persist through Sunday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Though a few patches of stratocumulus clouds are persisting, most of the forecast area is being enveloped by high clouds, in advance of the low currently progressing into the middle Mississippi Valley region. The one segment of the CWA currently escaping much in the way of any cloud cover is the northwestern section, where it would not be surprising to see temperatures take a sharper drop than previously forecast. Min temps were generally left unchanged through the rest of the CWA, but were raised slightly under the thicker high clouds in the south, and lowered slightly in the clear skies in the NW. The only other item of interest tonight is the possibility for fog. The signals from GFS/NAM numeric guidance, HRRR visibility, and RAP RH plots, have been -- at best -- spatially inconsistent. However, all have indicated at least a possibility of some visibility restrictions overnight. Surface dewpoints are highest (upper 40s) in the southeastern ILN CWA, which is also where winds are likely to become the lightest. Forecast confidence is too low to include fog everywhere, but this will be added into about a third of the CWA, generally along and southeast of a line from Licking County OH to Bracken County KY. Previous discussion > Surface analysis shows high pressure building into the Great Lakes, pushed by a northwest flow aloft. Low clouds lingering in a northerly low level flow behind departing surface low pressure will continue to erode gradually this evening as drier air works in, while high clouds move in as the upper flow becomes westerly. This will leave partly cloudy to mostly clear skies by later tonight, with more clouds remaining over eastern locations. Low temperatures are forecast to range from around 40 north up to the mid 40s south. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... For Thursday and Thursday night, we will find weak surface high pressure extending across the Great Lakes into the State of Ohio. Meanwhile, low pressure will be traveling through the Tennessee Valley. Precip with this rather compact low is expected to remain south of the ILN area, while cloud cover will be greater along and south of the Ohio River closer to the low pressure. Generous solar radiation will help boost temperatures up into the low to mid 60s for highs. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... An upper level s/wv and its associated weak cold front will move east across the region on Friday. These features will bring some clouds and perhaps a few showers, mainly post frontal. Highs will range from the lower to mid 60s. Models have trended much deeper/more pronounced on a long wave mid level trough digging into the Great Lakes and Ohio Valley Friday night into Saturday. Embedded s/wv energy digging on the back side of the developing mid level trough will accompany a cold front, bringing some clouds and a chance of showers, mainly across the northern zones Friday night into early Saturday. Partly to mostly sunny skies are forecast in the wake of the front on Saturday, but temperatures will show a downward trend with highs ranging from the lower 50s northwest to the lower 60s south/southeast. For Saturday night into Sunday, surface high pressure will build into the region from the northwest. Clear skies and winds becoming light Saturday night will probably result in some frost as temperatures drop into the lower to mid 30s. Will mention this threat in the HWO. On Sunday, despite sunshine, temperatures will be cool, mainly mid and upper 50s. As we head into early next week, the surface high will move east while a mid level ridge moves into the Great Lakes and the Ohio Valley. Dry weather, return flow, and sunshine, will result in a warming trend with all locations seeing 70s by Tuesday. There remains timing differences in the models on how fast mid level ridge will move east, which will eventually allow moisture and a cold front to move toward the region by mid to late week. For now, a chance of showers and thunderstorms will continue in the forecast for later Wednesday into Wednesday night well ahead of the cold front. It will remain warm with highs in the 70s again on Wednesday. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Generally VFR conditions are expected through the TAF period. As cumulus clouds dissipate somewhat this evening, an increase in high clouds is expected. Winds will also become lighter as they switch from the northwest to the north. The one forecast item worth mentioning is the potential for fog overnight. This is a low-confidence part of the forecast, but there does appear to be some potential for reduced visibilities, especially at the KCMH/KLCK/KILN sites. For now, MVFR visibilities will be introduced to the forecast, but there is at least some potential for IFR conditions. Clouds will continue to increase somewhat tomorrow, but VFR conditions should prevail. Winds will shift to the east but become very light (perhaps light and variable at times). OUTLOOK...MVFR ceilings are possible Saturday morning. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Coniglio NEAR TERM...Coniglio/Hatzos SHORT TERM...Coniglio LONG TERM...Hickman AVIATION...Hatzos
Area Forecast Discussion
National Weather Service Lake Charles LA
804 PM CDT Wed Apr 25 2018 .DISCUSSION... Updated POP/wx grids to account for radar trends as convection begins popping up over the wrn zones along the sfc boundary. Newer rain chances continue the earlier trend of undercutting MOS per high res guidance, but are a little closer to medium range guidance than previously. Update out shortly. 25 && .PREV DISCUSSION... /issued 623 PM CDT Wed Apr 25 2018/ AVIATION... Overall, the forecast thinking from the 18Z TAFs remains unchanged and only minor changes to account for timing/current observations were needed. Cloud cover will increase and ceilings will lower through the evening ahead of an approaching cold front. The front will be accompanied by showers and perhaps a thunderstorm or two. The timing for frontal passage looks to be around 05Z at KAEX, between 06Z-08Z at KBPT/KLCH, and 09Z-11Z at KARA/KLFT. Northwest winds around 10 knots will develop behind the front and continue through the day Thursday. Skies will clear Thursday morning and VFR conditions will continue through the day. PREV DISCUSSION... /issued 206 PM CDT Wed Apr 25 2018/ DISCUSSION... Wx map shows weak high pressure over the region, with light and variable winds this afternoon. A cold front continues to move southeast across C and NE TX, roughly just north of KCLL to KGGG to KTXK. South of the front, mostly clear to partly cloudy skies prevail across the region, with temperatures in the lower to mid 80s this afternoon. Clear skies per visible satellite imagery. Expecting mostly sunny to partly cloudy by the afternoon hours should allow temperatures to rise in the lower to mid 80s along and north of the I-10 corridor, upper 70s south to the coast. The cold front expected to arrive later this evening into early Thursday morning bringing scattered to numerous showers and isolated thunderstorms, mainly along the frontal passage. The latest HRRR not to excited about convection along the front, only generating scattered amounts. For this, lowered pops a bit later this evening and overnight to 40-50% along and north of the I-10 corridor, 30-40% further south into the Gulf. Not expecting severe weather with this event, SPC only outlining region in general thunderstorm area. Cooler and drier air expected behind the front Thursday. Another weak upper level system will bring a slight chance of precipitation on Friday, mainly across Central and South Central Louisiana. For the weekend into early next week, generally seasonal temperatures expected with little to no chances of precipitation until late Tuesday or Wednesday. DML MARINE... A cold front is expected to move across the coastal waters late tonight into early Thursday. A brief period of elevated offshore flow is expected behind the front. For this, included Small Craft Exercise Caution for the 20-60 nm zones from 4-10 AM Thursday. Light to moderate offshore winds expected into the weekend. DML && .PRELIMINARY POINT TEMPS/POPS... AEX 53 72 54 76 / 50 10 10 20 LCH 58 75 56 77 / 50 10 10 10 LFT 59 74 55 76 / 50 10 10 20 BPT 57 76 55 78 / 40 10 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...Small Craft Exercise Caution from 4 AM CDT Thursday through Thursday morning for GMZ470-472-475. && $$ PUBLIC...04
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1025 PM CDT Wed Apr 25 2018 .SHORT TERM...(This evening through Thursday) Issued at 300 PM CDT Wed Apr 25 2018 The short term concern remains timing of the cold front and increasing northwest winds and lower RH in the wake of the front. Fire weather concerns remain over west central MN into Thursday afternoon as drier air works into the region behind the cold front. We currently have upper 20s for lower RH across much of that area for now. We did mention the increased fire danger over the west for Thursday afternoon in the fire weather forecast. Temperatures were slow to warm under the steep subsidence inversion this afternoon. We may see readings mix to the lower 60s over mainly the east Thursday afternoon as the front exits the area. .LONG TERM...(Thursday night through Wednesday) Issued at 300 PM CDT Wed Apr 25 2018 The longer term concerns remain fire weather potential Friday afternoon across western Minnesota. Another frontal passage Friday morning will bring in increasing northwest winds and lower dewpoints to that region of the state once again. We will nee to monitor model trends concerning dewpoints/RH. Showers will be possible ahead of the frontal boundary/weak surface low. Moisture will be limited but lower end PoPs look reasonable at this time. Following this system we will see cooler temperatures through Friday. Warmer air should be on the rebound into Sunday as the upper flow pattern turns more southwest drawing in warmer/moist more air from the south. We should see more widespread highs in the 70s Sunday and continuing into early next week. Thunder threat increase as well, as short waves work northeast in that flow pattern into southern MN. At the present time, those chances look best Tuesday afternoon into Wednesday with the passage of a cold front. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1025 PM CDT Wed Apr 25 2018 Only change made to TAFs was to remove the VCSH mentions. The HRRR has been trending drier with the precip along the front all night, so removed what mentions we have. Timing for the FROPA still looked good. KMSP...It looks to be poor timing for the shift to northwest winds as it will be occurring during the morning push. We look to go from a 200 direction around to 330 over the course of about 2 hours. This 2 hour shift looks to begin around 12z or 13z. /OUTLOOK FOR KMSP/ FRI...VFR. Winds NW 15G25kts. SAT...VFR. Winds N, bcmg E late 5 kts or less. SUN...VFR. Winds SSE 15G25kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...DWE LONG TERM... AVIATION...MPG
Area Forecast Discussion
National Weather Service Nashville TN
828 PM CDT Wed Apr 25 2018 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... Echoes are showing up on radar crossing the TN River Valley, but drier air in the low levels is preventing any precip from reaching the surface thus far. As the upper shortwave gets closer to the area, showers will eventually win over the drier low levels and rain will begin in the west. Short term model consensus has showers beginning just before midnight in the southwest zones, and mainly impacting areas south of I-40 overnight. Some light rain out ahead/north of the better chances may impact other areas, but the better shot at rain will be in the morning and afternoon on Thursday. Just made some simple changes to match up with current obs trends, and tweaked pops a bit as well to line up with model consensus and current thinking. Rest of the forecast looks good. && .AVIATION... 00Z TAF DISCUSSION. VFR cigs will continue the rest of today and much of tonight at all airports as rain approaches from the west. -SHRA expected to reach BNA/MQY around 10-11Z, CKV around 12Z, and CSV around 14Z per latest HRRR model runs. Low level dry air look to keep cigs/vis in VFR/MVFR category after rain arrives. Light north winds this evening will become easterly on Thursday morning. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......Barnwell AVIATION........Shamburger
Area Forecast Discussion
National Weather Service Norman OK
1033 PM CDT Wed Apr 25 2018 .DISCUSSION... && .AVIATION... MVFR-level clouds over central and north central Oklahoma will move east of these areas this evening. VFR conditions will then return through the daytime Thursday; however, MVFR fog is possible for a few hours around sunrise in central and north central Oklahoma. North winds will become light this evening. && .PREV DISCUSSION... /issued 914 PM CDT Wed Apr 25 2018/ UPDATE...&& Added patchy fog mention late tonight into Thursday morning east of a Cherokee to Oklahoma City to Madill line. Made small adjustments to sky cover tonight. DISCUSSION... A cool night can be expected tonight with clearing skies, light winds, and surface high pressure overhead. Added the fog mention based on latest mesonet observations showing low surface dewpoint depressions, generally 6F or less as of 9 pm. Also, latest HRRR runs have been hinting at the possibility of fog in these areas, especially where little sunshine occurred earlier today. Think fog will mainly be confined to low- lying valleys and should not get widespread or too dense with visibilities generally 1/2 to 3 miles. Any fog will quickly dissipate between 7 and 9 am Thursday morning. Cannot rule out patchy frost in some locations, mainly rural low-lying valleys across northern Oklahoma later tonight. Think any frost will be very localized, so did not issue a Frost Advisory, as lows should remain above 36F in most locations. Lows tonight will remain on the cold side. Forecast lows mainly in the upper 30s and lower 40s seem to be reasonable. Daily record low temperatures for April 26 are 35F at Oklahoma City set in 1907, 40F at Wichita Falls set in 1947, and 36F at Lawton set in 1983. Don`t think these records will be broken, though readings will be fairly close. MBS && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ 17/09