Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/15/17

Area Forecast Discussion
National Weather Service Cheyenne WY
944 PM MDT Fri Apr 14 2017 .UPDATE... Issued at 944 PM MDT Fri Apr 14 2017 Strong storms developed earlier in the southern Panhandle counties but have since moved off to the east. Current radar shows scattered shower activity with isolated thunderstorms still ongoing across Goshen & eastern Laramie Counties in Wyoming, and points eastward into the Nebraska Panhandle. Expect this to continue for a few more hours as mesoanalysis suggests there remains sufficient elevated instability to maintain convection. Also, upgraded to a Red Flag Warning for tomorrow as forecast models continue to suggest critical fire weather conditions are conducive to supporting fire growth in FWZ 306, 309, 312 & 313. && .SHORT TERM...(This evening through Sunday night) Issued at 225 PM MDT Fri Apr 14 2017 Forecast challenges deal with convection today followed by fire weather concerns Saturday. Currently...Frontal boundary currently lays roughly along a line from Chadron to just west of Cheyenne (almost overhead) at this time. CYS ASOS still reporting a northeast wind, so front has not made it to the east yet. Mid 40 dewpoints being reported in the Panhandle at this time. Latest SPC mesoanalysis page showing a slightly capped environment for areas east of the front with 50 to 75 J/KG convective inhibition. Across the southern Panhandle, SBCAPEs are on the order of 700-1200 J/KG, so there is some potential for some convection to get going this afternoon. West of the front across northwestern Wyoming, a very dry airmass is in place with dewpoints in the low to mid teens. Rest of this afternoon...Front is forecast to move east through the late afternoon and this evening. Latest HRRR guidance shows convection developing after 22Z this afternoon and drift northeast into the Panhandle during the early evening hours. Slight cap seen on GFS soundings around 600mbs for the Panhandle could limit convection. Will take a wait and see approach, but did keep some mention of showers and thunderstorms in the forecast, especially for the Panhandle. Front moves into central Nebraska later this evening with convection ending after 03Z or so. West to northwest winds on the increase tonight into Saturday with that drier air moving overhead. GFS 700mb winds increasing to 30-35kts Saturday morning with mixing up close to 500mbs tomorrow afternoon. Did go on the low side on dewpoints for Saturday and have wind gusts 35-40 MPH widespread. Hoisted Fire Weather Watches for all zones that still have fuels reported as ready. Winds really ease Saturday night into Sunday. So maybe we will be ok fire weather wise. Will need to watch this though as afternoon humidities continue to be quite low. .LONG TERM...(Monday through Friday) Issued at 225 PM MDT Fri Apr 14 2017 Mild weather continuing Monday with a passing shortwave clipping the CWA and bringing some showers and maybe a few storms to mainly the plains late in the day. Most of Tuesday looks to be dry with mild conditions persisting. Rest of the week should see a general cooling of temperatures along with increasing chances for pcpn as upper troughing develops over the western CONUS and several impulses move by the region. Models differ on timing with these disturbances with one moving across about Weds then the next one Thursday night into Friday. The second system is trending more southward with the GFS keeping its pcpn shield south of the CWA. EC farther north but its latest run shifted southward. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 613 PM MDT Fri Apr 14 2017 Scattered showers with a few t-storms continue to move to the northeast across the plains of WY and NE at 00Z. So far, observed wind speeds have been on the light end with this activity. Will see t-storms continue to move east into the panhandle through about midnight before dissipating. Widespread gusty northwest winds of 25 to 30 kts will develop through Saturday morning and will continue through the day. && .FIRE WEATHER... Issued at 225 PM MDT Fri Apr 14 2017 West to northwest winds are expected to become widespread and gusty Saturday behind a departing frontal system currently located along the east slopes of the Laramie Range. Very dry air behind the front will filter into the area tonight and will be in place once these winds do become gusty. Areas where fuels are reported receptive for rapid fire spread are under a Fire Weather Watch for Saturday afternoon. The dry air will stay in place for Sunday, but winds are expected to be much less, keeping fire weather conditions in check. Wetter conditions return Tuesday night with unsettled weather continuing the rest of the week. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Red Flag Warning from noon to 7 PM MDT Saturday for WYZ306-309. NE...Red Flag Warning from noon to 7 PM MDT Saturday for NEZ312-313. && $$ UPDATE...RJM SHORT TERM...GCC LONG TERM...RE AVIATION...RJM FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Dodge City KS
658 PM CDT Fri Apr 14 2017 ...UPDATED AVIATION SECTION... .SHORT TERM...(This evening through Saturday) Issued at 227 PM CDT Fri Apr 14 2017 As of 2 pm am continuing to monitor the potential for thunderstorm development along a dry line which was located across far western Kansas. Latest RAP and HRRR continue to favor only an isolated thunderstorm or two at best late today. Even the 12z ARW and NMM, which are notorious for overdoing the cold pool production, has backed off on convection along this boundary. so will begin to trend more towards that direction and lower the chances of precipitation. Although lowered thunderstorms chances early this evening if any storm does develop it still may produce some hail and gusty winds. Gusty southwest winds at 15 to 20 mph will continue overnight east of the dry line which will retreat westwards slightly during the overnight period. This should aid in keeping temperatures up tonight. Lows 55 to 60 still look on track. During the day on Saturday this dry line will surge east across western Kansas as a cold front drops south and begins to overtake this surface boundary. Models still differing some on the location of these surface boundaries late Saturday but all in generally in good agreement in placing the cold front in south central Kansas and the cold front/dry line intersection near of just south of the Oklahoma border. Strong to severe thunderstorms will be possible along both of these boundaries late Saturday afternoon and early Saturday night. Better shear and instability will be present along with better low level forcing so it currently appears hail size in excess of 2 inches will be possible late Saturday along with strong damaging winds. .LONG TERM...(Saturday night through Friday) Issued at 227 PM CDT Fri Apr 14 2017 Saturday night a frontal boundary will move south into northern Oklahoma where it will become stationary through early Monday. Models still differing on location of this boundary late this weekend into early next week but they all do support moisture and lift developing north of this boundary which will result in at least increasing clouds. There may also be a chance for precipitation across western and central Kansas late this weekend into early next week. At this time the better chances still appear to be near the Oklahoma border and across south central Kansas where the better moisture and lift will be present. Early next week this surface boundary will lift north as a warm front as the precipitation chances end from west to east Monday night into Tuesday. Temperatures are expected to rebound back into the 80s on Tuesday. A cold front will move into southwest Kansas mid week which will bring an end to the warming trend and also provide another a chance for thunderstorms along with more seasonal temperatures back to western Kansas. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 646 PM CDT Fri Apr 14 2017 There could be convective initiation this evening, focused in the zone from around Garden to Dodge City, based on HRRR/WRF/NMM. However, at this time the chances look to low to include in a terminal even at a Prob30. A very strong 850 mb low level jet will be ongoing tonight, with 50+ knot winds across the area, resulting in strong low level wind shear. Outside of a low chance of convection, any clouds should remain VFR level through this TAF period. && .PRELIMINARY POINT TEMPS/POPS... DDC 57 78 51 68 / 10 20 30 30 GCK 53 77 50 66 / 20 10 20 20 EHA 52 78 49 68 / 20 10 20 20 LBL 56 81 52 69 / 20 10 20 30 HYS 60 75 50 68 / 20 20 20 20 P28 60 78 56 70 / 10 30 50 40 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Russell
Area Forecast Discussion
National Weather Service Houston/Galveston TX
844 PM CDT Fri Apr 14 2017 .DISCUSSION... No significant changes to make for the evening update. The moisture axis associated with the upper level trough was over the Red River and points east at mid evening. A few isolated showers were well offshore and out of the marine areas of responsibility. High clouds will begin drifting overhead the inland forecast area later this evening and overnight from the convection currently occurring along and ahead of the dry line over the western part of the state. 40 && .PREV DISCUSSION... /ISSUED 630 PM CDT Fri Apr 14 2017/ AVIATION.../00Z TAF/ Radar imagery shows a few isolated showers still remaining over SE Texas this evening. These showers should be dissipating and not affect any terminals. Overnight it looks like a possibility of scattered low clouds for the Houston terminals southwards along the coast. Combination of winds decoupling and moisture near the surface should support MVFR to LIFR ceilings at CXO/UTS/CLL for a few hours in the morning. There is a small chance MVFR ceilings could develop for an hour or two over the Houston terminals but not enough to put in TAF at this time. There may be an isolated shower again tomorrow during the day but models not showing much precip so keeping TAFs dry. Overpeck PREV DISCUSSION... /ISSUED 313 PM CDT Fri Apr 14 2017/ DISCUSSION... Isolated showers have been developing across the southern half of the area so far today, but will continue to spread inland through the rest of the afternoon with a few thunderstorms possibly mixed in. Patchy fog is forecast overnight tonight into tomorrow morning, especially across areas that receive rainfall today. Tomorrow is expected to be drier as PWs lower a bit and the upper-level weakness helping convection develop today shifts off to the east and weak upper-level ridging moves in. Sunday through midweek will generally have isolated to scattered diurnal convection as PWs increase slightly and a series of upper- level weaknesses rotate across Texas. By midweek, upper-level ridging will take hold over the region, diminishing chances for precip and allowing high temperatures to climb into the mid 80s each day through Friday. Next frontal system looks to approach next weekend, but timing differences have yet to be resolved. The latest (12Z) GFS and ECMWF runs are not all too different with the timing, bringing the front into SE Texas sometime around Saturday morning. However this is faster than previous runs for both models, especially the ECMWF, and for that reason confidence remains fairly low for now. 11 MARINE... Surface ridging off to the east will keep persistent light to moderate onshore flow through next week. The next cold front may arrive next weekend, but confidence remains low on the timing for now. 11 PREV DISCUSSION... /ISSUED 1230 PM CDT Fri Apr 14 2017/ AVIATION... For the 18Z TAFS, have added VCSH for this afternoon at SGR (based on current activity) and at CLL (based on possible radar trends and some model guidance). HRRR has been showing more activity this morning than has developed, so not confident enough at this time to add any VCSH to other TAF sites. Will continue to monitor radar and model trends (and amend the TAFS if needed) as more activity looks like it is trying to develop closer to the GLS area. Otherwise, looking for mainly SCT/BKN 3500-5000 foot decks around inland sites this afternoon, clearing this evening (just some high clouds), possible MVFR/IFR ceiling and/or fog development overnight and improving conditions tomorrow morning. Best chance of rain over the weekend still looks like it should be on Sunday. 42 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 62 82 66 82 66 / 10 10 10 30 10 Houston (IAH) 65 83 67 83 67 / 10 10 10 30 10 Galveston (GLS) 70 78 72 78 72 / 10 10 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ Discussion...40 Aviation/Marine...39
Area Forecast Discussion
National Weather Service Lincoln IL
858 PM CDT Fri Apr 14 2017 .UPDATE... Issued at 858 PM CDT Fri Apr 14 2017 Showers are quickly dissipating or departing to the east-northeast as the warm front lifts north of our forecast area. Have subsequently diminished PoPs and Weather across the board the rest of the night. Satellite images are indicating the clearing will arrive a bit sooner than previously expected, so have updated the sky forecast to reflect those trends. Despite the clearing of clouds, we still expect a mild night due to persistent southerly winds in the warm sector. Lows should bottom out in the upper 50s to low 60s. The remainder of the forecast looks on track. Updated forecast info will be available shortly. && .SHORT TERM...(This evening through Saturday) ISSUED AT 257 PM CDT Fri Apr 14 2017 A warm front has settled across northern Illinois this afternoon, leaving Central IL in the upper 70s and lower 80s as warm air surges northward. As an upper air disturbance moves closer to the region from the west...showers and thunderstorms are developing on radar and spreading in coverage. Sct cu field on satellite and HRRR pointing toward further development through the afternoon and early evening. Through the overnight, precip should come to an end from west to east, and mainly dry by morning. Overnight lows will be generally mild in the 50s. Saturday will be a warm and breezy day across the region. Winds just off the surface will mix down so gusty conditions can be expected from mid day through the afternoon. For the most part the day will be dry...but will begin to see showers and thunderstorms moving into the region in the overnight hours tomorrow night. .LONG TERM...(Saturday night through Friday) ISSUED AT 257 PM CDT Fri Apr 14 2017 Main surface low with the storm system developing to the west is expected to lift northward and drag a cold front into and through the region overnight tomorrow night. Showers and thunderstorms initially moving in NW of the IL River Valley will bring a marginal chance for severe weather depending on the timing of the boundary with the max heating/instability into the evening hours. Showers and thunderstorms should be slow to end...lingering into Easter Sunday, particularly in the southern half of the state...with the ECMWF lagging behind the faster GFS. Midwest spends a short time in more zonal flow aloft until the next wave develops across the Upper Midwest on Tuesday, moving a quick trof/sfc boundary through the state midweek with the next chance for showers and thunderstorms. Model blends are having a hard time going completely dry in any particular period as the pattern is shifting to a more rapid flow across the country with a series of short waves. Temperatures will remain slightly above normal throughout most of the 7 day forecast. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 703 PM CDT Fri Apr 14 2017 showers and storms are dissipating in coverage and intensity early this evening with the stabilization of the boundary layer. Have included VCTS only at CMI, based on radar trends and expected storm movement. Even shower coverage will be greatly diminished in another hour or two, with an isolated shower possible 02z-05z. Winds will generally remain south to southeast as the warm front lifts north of central Illinois. An intensifying low level jet will set the stage for LLWS at all terminal sites after 05z-06z tonight through sunrise tomorrow. WS020/21040kt appears reasonable for now. Gusty surface winds look on track for tomorrow as the LLJ mixes down to winds to the surface, with 15-20G27kt. VFR conditions should prevail throughout the next 24 hours. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Shimon SHORT TERM...HJS LONG TERM...HJS AVIATION...Shimon
Area Forecast Discussion
National Weather Service Indianapolis IN
1010 PM EDT Fri Apr 14 2017 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 200 PM EDT Fri Apr 14 2017 A warm front pushing to northern Indiana along with Low pressure in place over the Central Plains States will lead to a warm start to the weekend. An upper level weather disturbance will push the warm front farther north and may trigger afternoon and evening showers or storms across Mainly Western parts of Central Indiana. On Saturday...Southerly winds ahead of the low will continue to stream warm and moist air into the Ohio valley. An isolated shower or storm cannot be ruled out on Saturday...but many dry hours will be expected. A cold front will sweep across Indiana on late Saturday Night and Sunday. It is at this time the best chances for showers or storms over the weekend will exist. The rain threat will end by Sunday night as the cold front departs the area before stalling near the Ohio River for Monday. Weak high pressure will build across Indiana on Monday...providing dry weather...however rain chances may persist across southern Indiana neat the lingering front. This front will stall across Kentucky and northern Tennessee and then will move back to the north by mid week as another area of low pressure moves from the central plains to the great lakes. && .NEAR TERM /Tonight/... Issued at 929 PM EDT Fri Apr 14 2017 Vorticity lobe continues to lift northeast across the local area. Most of the earlier activity has dissipated, except over the northwest zones, where the 850mb flow is better. Appears main precipitation threat will end around 150700Z or so when vorticity center drifts off to the northeast. Will keep some PoPs going mainly over the northwest until that time. Previous discussion follows. Surface analysis early this afternoon shows Low pressure over the Central plains. A warm front was found across the northern parts of Central Indiana...with easterly flow in place across the northern parts of the state and the warmer southerly flow in place across the south. dew points have climbed in to the 50s. Water vapor imagery shows a short wave and surge of moisture streaming northward into Illinois and NW Indiana. Radar shows a few showers trying to develop along the front. Models continue to suggest the short wave to the west will lift north...but mainly missing much of central Indiana with the best forcing remaining northwest of the forecast area. Meanwhile the surface warm front is expected to lift farther northward...and we lose a foal point for development to the north. HRRR appears to the be the most aggressive with precip chances this afternoon as but contains returns to mainly the NW areas. Still forecast soundings continue to suggests convective temps in the upper 70s with 1400 j/kg of CAPE. THus will continue low chc pops this afternoon and early evening as daytime heating dwindles and the associated dynamics slide north. As Central Indiana gets deeper within the warm air advection...will continue to trend lows at or warmer than a forecast builder blend. && .SHORT TERM /Saturday through Monday/... Issued at 200 PM EDT Fri Apr 14 2017 Models hint at low precip chances for Saturday and Saturday evening. Indiana looks to remain deep within the warm sector with little in the way of upper support arriving on Saturday. The previous warm front and short wave should be well to the north. However forecast soundings continue to suggest attainable convective temps in the afternoon along with CAPE near 1400 j/KG again. Given this...cannot rule out a stray shower/storm...but many hours will remain dry along with breezy and warm south winds. Thus will keep a low pop mention contained to the late afternoon hours. Given the good warm air advection and southerly flow will trend Saturday highs at or above a forecast builder blend. GFS and NAM then suggest the arrival of a cold front late on Saturday night. Good mid level moisture appears to pass across the region on Sunday morning and forecast soundings show deep saturation. Time heights also hinting at good forcing and lower level moisture. Thus will keep many hours of Saturday evening begin to ramp up pops on after midnight and continue high pops on Sunday morning. GFS suggests the cold front will sag to southeast Indiana by 00Z Monday...but the bulk of the moisture should be ahead of the front. Thus will trend pops lower during the afternoon hours...toward a dry forecast for Sunday night as High pressure arrives in the area. Will trend lows on Saturday night warmer than the blend given the expected precip and warm air advection. Will stick close to highs on Sunday as an air mass change will be underway. GFS suggests zonal flow in place on Sunday night and Monday as High pressure arrives the surface. Flow aloft shows no upper support...thus mainly dry weather is expected. Models hint as the previous cold front stalling out somewhere near the Ohio River...and this will probably result in the blend including at least some pops across the south. However confidence in this will be low for now. && .LONG TERM /Monday Night through Friday/... Issued at 158 PM EDT Fri Apr 14 2017 Model guidance depicts an active period with multiple disturbances moving across the country along a fluctuating baroclinic zone across much of CONUS. Model blend initialized with pops basically every period, which is almost certainly way overdone, but pinning down any one period to be dry is a difficult task. Will generally adhere to regional initialization, but with the caveat that all day washouts do not appear likely. && .AVIATION /Discussion for the 150300Z KIND TAF Update/... Issued at 1007 PM EDT Fri Apr 14 2017 No significant changes made to the forecast at this time. Previous discussion follows. A vorticity lobe currently extending from eastern Iowa into southwest Indiana is expected to drift northeast during the evening hours. Widely scattered convection possible in association with this feature. The best chances for convection appear to be in the KLAF vicinity, which is closest to better 850mb flow. Short term model guidance suggests this feature will pass off to the northeast of the terminals around 150400Z, resulting in a diminished threat after that time. CB bases around 050. Otherwise, outside of convective areas, scattered to broken layers above 050 tonight along with unrestricted visibility. Surface winds 150-180 degrees at 5-9 kts. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Puma NEAR TERM...Puma/JAS SHORT TERM...Puma LONG TERM....NIELD AVIATION...JAS
Area Forecast Discussion
National Weather Service North Platte NE
638 PM CDT Fri Apr 14 2017 .SHORT TERM...(This evening through Saturday) Issued at 338 PM CDT Fri Apr 14 2017 Thunderstorms are expected to become scattered near and north of Interstate 80 tonight. Discrete storms will be possible early this evening east of a line from Hayes Center through North Platte and Callaway, with a few storms capable of large hail and damaging wind gusts. A dryline bulge is forecast to push into southern Hayes and Frontier County by early evening with a warm front just to the north. The latest runs of the HRRR and RAP models are in similar agreement with this location. Other isolated storms may develop along a surface trough across the western Sandhills early evening. As the boundary layer cools, the surface based storms will diminish or move east of the forecast area. Elevated storms will then develop northward as the evening progresses. Storms should become more numerous as a low level jet develops across our southeastern and eastern zones, and a cold front across the northwest pushes southeast overnight. With storm motion only 10 kts to the east and northeast, locally heavy rainfall may occur. The higher chances for showers and storms overnight will be east of a line from Broken Bow, Thedford and Ainsworth. The elevated storms will still be capable of nickel size hail and gusty winds along with locally heavy rainfall. Lingering showers possible Saturday morning in the northeast, otherwise the remainder of the weekend looks dry. Highs Saturday will be cooler behind the Pacific cold front from the mid 60s northwest to around 70 southeast. Elevated fire weather condition to develop Saturday afternoon across the southeast panhandle into southwest Nebraska with relative humidity falling to 15-20 percent and northwest winds gusting to around 20 mph. .LONG TERM...(Saturday night through Friday) Issued at 338 PM CDT Fri Apr 14 2017 Slightly warmer Sunday near 70 with light southerly winds increasing to 5 to 15 mph in the afternoon. Sunday night, the upper flow remains zonal with a weak cold front across the area. An increase mid mid level moisture and a weak disturbance will bring a chance for showers, followed by a stronger and deeper upper trough approaching and moving across Monday afternoon and Monday night. A surge of Gulf moisture into the region with weak instability and mid level lapse rates near 7.5 c/km, thunderstorms are possible. Models agree on an organized thunderstorms complex tracking across the Dakotas into north central and central Nebraska overnight. Another upper trough cross the area Tuesday night into Wednesday providing another chance for showers and a few thunderstorms. Off and on shower chances Wednesday night through Friday, as a trough and closed low tracks into the Four Corners Region. Medium range models consensus is for much of the showers and thunderstorms to be focused from Kansas southward on Friday, with some chance that model could trend northward and bring higher chances to Western Nebraska. Highs remain above normal Monday and Tuesday in the upper 60s to lower 70s. Forecast highs in the 60s Wednesday and Thursday, then mid to upper 50s Friday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 639 PM CDT Fri Apr 14 2017 For the KLBF terminal: There will be a small threat for thunderstorms tonight and will handle mention of them with vicinity wording for now. Otherwise, ceilings will generally be in the 7000 to 10000 Ft Agl range overnight with clearing skies expected Saturday afternoon. For the KVTN terminal: Expect scattered high cloudiness to persist overnight with a small threat for thunderstorms from 06z to 10z Saturday. Otherwise, expect scattered to broken ceilings from 5000 to 7000 Ft Agl with clearing expected Saturday afternoon. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Roberg LONG TERM...Roberg AVIATION...Buttler
Area Forecast Discussion
National Weather Service Miami FL
810 PM EDT Fri Apr 14 2017 .AVIATION...Brisk east-northeast flow continues through TAF cycle. Isold Atlc SHRA will continue, and can`t rule out one affecting the east coast TAF sites. However, any associated MVFR conditions will be brief. Based on current radar/sat trends, will keep VCSH out of the forecast for the moment. East coast sites will see winds diminish to 8-12kts overnight, generally stronger at KFLL, then increases out of due east 15-18G25kts after 13Z- 15Z. && .UPDATE... Surface analysis continues to indicate a strong 1030 mb surface high centered over New England. Clockwise flow around this feature will maintain moderate to strong easterly winds across South Florida this evening into tonight, especially along the east coast metro region. NWS radar loop shows bands of showers streaming onshore from the Atlantic. Short term models, including the HRRR and Hi- Res WRF prog hit and miss showers to continue through at least sunrise on Saturday. With the update, increased to chance PoPs over Miami-Dade county/the adjacent waters and loaded in the latest short term wind guidance. Otherwise, all other forecast variables appeared on track. && .PREV DISCUSSION... /issued 435 PM EDT Fri Apr 14 2017/ DISCUSSION... Through Saturday night: Latest water vapor imagery shows ridging over the eastern CONUS with dry air aloft over the Florida peninsula. Surface analysis shows a 1030 mb surface high positioned over the mid Atlantic coast. This feature will be responsible for much of our weather experienced over the next 24-36 hours. Clockwise flow around this high has produced breezy east northeast winds across our CWA today, mainly ranging from 10 to 20 mph. By this evening, models begin to slowly advect the aforementioned feature to the east southeast. This will help to tighten surface pressure gradients across the Florida peninsula and increase easterly flow. Tonight, strongest winds appear to remain along the east coast, sustained at around 15 mph. Light to occasionally moderate showers will continue to stream onshore from Atlantic, but instability parameters look dismal, so do not expect any organized convection or much accumulation associated with this activity. Mixing in the lower levels should discourage the development of fog over the interior. On Saturday, the surface high will continue to meander to the southeast, maintaining breezy easterly flow. On average winds will be sustained 15-20 mph across the CWA, strongest along the east coast, where winds from the ocean experience the least amount of friction. Due to the flow pattern, maximum temperatures will struggle to reach 80 degrees along the east coast metro, with mid 80s further west. By sundown, with the last of daytime heating/mixing, winds to begin to wane. There be a slight chance of showers along the east coast metro tomorrow night as well, otherwise dry conditions elsewhere. Sunday through mid next week: As the center of surface high pressure migrates further east, over Bermuda, the surface pressure gradients will begin to weaken. Easterly to east southeast flow will continue over Florida through the period, but not as strong as Saturday. Both the 12Z ECWMF and GFS models indicate deeper moisture advecting northward from the Carribean over our CWA. If current projections are correct, precipitation chances will increase throughout the week over South Florida with moist southeast flow. MARINE...High pressure building over Bermuda will keep the fetch from the northeast to east for the next several days. The pressure gradient looks to be strong enough for the wind to increase to 20 to 25 kts over the Atlantic waters tonight. This would cause seas to build to 6 to 7 feet across the Atlantic waters, especially in the Gulf Stream. A Small Craft Advisory has been issued for the Atlantic waters, including Biscayne Bay, which is in effect through Saturday night. Along with the high wind and seas, there looks to be increasing chances of rain showers , particularly from the middle of next week possibly into the weekend. BEACH FORECAST...Breezy northeast to easterly wind will bring a high risk of rip currents for the Atlantic beaches through tomorrow night. Strong rip currents may occur into Sunday with easterly winds weakening slightly by Saturday night. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 72 81 70 80 / 30 20 20 10 Fort Lauderdale 73 80 71 80 / 30 20 20 20 Miami 71 81 71 81 / 30 20 20 20 Naples 64 86 64 83 / 10 10 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through Saturday evening for FLZ168-172- 173. AM...Small Craft Advisory until 8 AM EDT Sunday for AMZ630-650-651- 670-671. GM...None. && DISCUSSION...27/JT UPDATE...27/JT AVIATION...88/ALM MARINE...27/JT BEACH FORECAST...27/JT
Area Forecast Discussion
National Weather Service Raleigh NC
927 PM EDT Fri Apr 14 2017 .SYNOPSIS... High pressure will linger over the central NC through Saturday. Much warmer temperatures will arrive Sunday as the high pressure drifts offshore. && .NEAR TERM /THROUGH TONIGHT/... As of 925 PM Friday... Temperature observations a little random as of 1z as some patchy clouds and calm winds have combined to either keep temperatures warmer longer, or cool them quicker than anticipated so far this evening. Therefore have low 60s to low 70s across the area right now with lows expected to eventually bottom out in the mid to upper 50s. Looking at GOES-16 infrared imagery, some more clouds are on the way overnight, particularly across the north as a vort max moves closer to the area. These clouds should remain VFR. Further to the south, there is some question for some low stratus which for the most part is expected to stay south of the forecast area. That being said, SREF and HRRR model data suggest low stratus extending northward along the I-95 corridor by sunrise. The only chance for showers, and minimal at best will be across the northern VA border counties as the vort max comes closer to the area later Saturday morning. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... As of 240 PM Friday... Sfc high pressure will sit off the mid-Atlantic coast Saturday, while an upper ridge will be centered over the Carolinas. Anticyclonic flow around the surface high will continue to advect low-level moisture from the Atlantic northwestward into the area, maximized in an arc along the eastern upslope regions of the southern Appalachians. Daytime heating and resultant weak destabilization will result in scattered convection along the NC foothills and mountains, which could propagate southeastward into the NC Piedmont within the NWLY steering flow. Additionally, will also have to be cognizant of any upper level disturbances tracking atop the ridge and through the Mid-Atlantic States, though such activity looks to be east of the area by mid morning. Highs Saturday are expected to be in the upper 70s to lower 80s. Any convection is expected to die off with the loss of heating. Lows in the upper 50s to near 60. && .LONG TERM /SUNDAY THROUGH FRIDAY/... As of 120 PM EDT Friday... Sun/Sun Night: Central NC will remain on the southern periphery of the westerlies this weekend, on the northern periphery of an upper level ridge shifting offshore the Southeast coast. Weak low-level convergence associated with a pre-frontal trough will be present during the aft/eve, as will weak DPVA assoc/w small amplitude waves progressing east along the southern periphery of the westerlies. Despite strong insolation and modest mid-level lapse rates (6-6.5 C/km), GFS fcst soundings indicate that marginal moisture (characterized by dewpoints in the mid 50s and PWAT values < 1.00") will preclude more than 250-500 J/kg of MLCAPE during peak heating, primarily N & NW of the Triangle, while warmer H8/H85 temps cap the atmosphere S & E of the Triangle. NAM forecast soundings, on the other hand, show a thoroughly dry/stable/capped airmass in place over all of central NC. With the above in mind, a conditional potential for isolated diurnal convection cannot be ruled out Sun aft/eve, primarily N & NW of the Triangle where thermal profiles may be marginally supportive and low-level convergence will be augmented by DPVA during peak heating. Alternately (assuming GFS profiles are reasonable) , upstream convection in the Appalachians could propagate downstream into the N/NW Piedmont late Sun aft/eve. Expect above normal temperatures with highs in the lower/mid 80s on Sun. Mon-Tue Night: A cold front approaching the mountains from the NW will weaken and assume more of a W-E orientation across the Mid- Atlantic during the day Monday, then track slowly southward into central NC as a backdoor cold front late Mon night/Tue. With a low amplitude synoptic pattern in place over the region, there is significant uncertainty w/regard to the evolution of the front. As such, confidence in precip chances and temperatures Mon night-Tue night are below average for this range in the forecast. In general, expect continued warm conditions on Monday with increasing chances for convection Mon aft/eve, followed by increasing cloud cover Mon night and cooler temperatures (esp N/NE) on Tue. The latest guidance suggests the front may stall over or near central NC Tue into Tue night. If so, chances for convection would persist, with the best chance along and north of the front in the N/NW Piedmont. Wed-Fri: An upper level ridge is expected to build along the central Gulf coast mid to late next week, with NW flow aloft returning to the region Thu/Fri. Expect above normal temperatures and increasing chances for diurnal convection Thu/Fri as NW flow aloft becomes established. -Vincent && .AVIATION /00Z Saturday THROUGH WEDNESDAY/... As of 745 PM Friday... While VFR conditions will be common across most of central NC through 10Z Saturday, pockets of MVFR due to ceilings or fog may develop after 06Z across the southern counties including KFAY, with the chance for MVFR/localized IFR parameters increasing between 10Z- 013Z Saturday. The threat for MVFR conditions due to ceilings may increase in vicinity of KRDU during this time. Any fog or stratus that develops should lift and burn off by mid morning Saturday. After 12Z Saturday, a few showers may skirt north of KRDU and KRWI though probability of showers affecting these terminals appears remote at this time. Otherwise VFR conditions should persist through Saturday evening. Aside for some sub-VFR visibility or ceilings due to fog or patchy stratus each morning, VFR conditions are generally expected to linger through MOnday morning. Shower and thunderstorm coverage will increase Monday afternoon/evening with an approaching cold front. The front could stall across the area Tuesday/Wednesday, resulting in scattered showers and storms each day. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...RAH NEAR TERM...Ellis SHORT TERM...CBL LONG TERM...Vincent AVIATION...WSS
Area Forecast Discussion
National Weather Service Blacksburg VA
928 PM EDT Fri Apr 14 2017 .SYNOPSIS... A warm front will progress slowly northeast across the region overnight into Saturday before reaching New England by Sunday morning. A cold front will head southeast through the Great Lakes region on Sunday, reaching our area on Monday, and stalling near the Virginia, North Carolina border on Tuesday. This same front will return north as a warm front Wednesday into Thursday as yet another cold front arrives on Friday. && .NEAR TERM /THROUGH SATURDAY/... As of 915 PM EDT Friday... Analysis showing that a tongue of low level moisture has returned into far southern sections this evening where have seen isolated showers along the NC foothills. However earlier weak instability has all but faded and given continued building heights would only expect an isolated shower across southern/eastern sections at best overnight. HRRR has been hinting at a few added showers as the surface warm front edges northeast later tonight but quite iffy after loss of heating. Thus trimmed back going pops a bit with varied degrees of clouds likely early on as sheared moisture drops over ridging aloft. Similar to last night, evening soundings indicate weak low level southeast flow that models suggest will again combine with moisture under the inversion aloft to produce another round of low clouds late per latest Nam. Since dewpoints are higher will continue this trend but may be around daybreak before any stratus or fog development takes shape given lingering dry air aloft. Otherwise few changes to going lows with mostly mild 50s expected outside of the deeper valleys per gradual moistening and some light mixing in spots. Previous discussion as of 230 PM EDT Friday... In the wake of morning stratus, mostly sunny skies has yielded an increase in cumulus clouds from eastern Bland County southward and westward along the southern Blue Ridge associated with a weak surface convergence axis. Modest instability is accompanying this activity, on the order of 500 to 1000 J/kg of SBCAPE. To the east, a surface high centered south of Long Island was inducing a fair amount of easterly flow and slightly cooler thermal profiles mainly into eastern Virginia. To our north and northwest, a warm front extended from near Chicago southward through northern Virginia. For Tonight: Any diurnal, isolated to widely scattered showers or thunderstorms should dissipate with sunset. Thereafter, it appears per model guidance that easterly flow again builds into the region for the late evening into the overnight hours. Generally speaking, areas that saw stratus this morning will probably see another round of low clouds again tonight, building southwestward from the Virginia Piedmont. Potential for patchy fog or mist as well, particularly in an axis of narrow T/Td spread along and south of route 58 where dewpoints should be in the mid 50s. Should see less cloudiness from the Mountain Empire and into our southeastern West Virginia counties, but not likely to be a clear night even in these far western areas as well. Lows run from the upper 40s to near 50 to the middle 50s, warmest along and east of the Blue Ridge. For Saturday: Likely to see early-morning stratus again, though with wind flow becoming more of a southerly to southwesterly, that should aid in eroding the overcast. Mid-level ridge then builds into the southern Carolinas, with the ridge axis building east of the Blue Ridge by afternoon. With the erosion of early morning cloudiness, should see deepening cumulus again in the afternoon, and the potential for scattered showers and thunderstorms with afternoon CAPE values rising to around 1000 J/kg per the GFS (and slightly higher than that in the NAM solution). Higher-resolution guidance generally points to the top of the mid-level ridge axis and slightly stronger belt of westerly flow, pretty much our northern and central tier of counties along and north of Route 460 southwestward into the southern Blue Ridge in North Carolina. PoPs kept no higher than Chance as there`s questions on where a focused source of lift could be found. If storms can develop, low wet-bulb zero values at or under 10 kft may yield some smaller hail. So something to keep close monitor of for tomorrow. Highs Saturday rise back well into the 70s with a modest southwest breeze. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... As of 200 PM EDT Friday... Saturday evening, anticipate any lingering showers from Saturday afternoon to dissipate fairly early in the evening with the loss of sunshine, and the departure north of the passing warm front to our north. The remainder of the night will bring decreasing cloud cover with temperatures on the mild side. A cold front will slowly approach the area on Sunday, reach the area late Sunday night, and cross the region on Monday. Sunday is expected to be a near repeat of Saturday from a precipitation stand point. Any substantial forcing will still be upstream of the region closer to the location of the cold front. However, orographic influences and the heating of the day a progressively more moist atmosphere, will lead to another day of isolated to scattered showers with the focus for best coverage across southeast West Virginia and along and near the spine of the Blue Ridge from roughly Roanoke and points southwest into the Northern Mountains of North Carolina. Isolated thunderstorms will also be possible in this same region in the afternoon. Little if any activity is expected east of a Reidsville, NC to Lynchburg, VA line. Look for precipitation chances to increase overnight, reaching the likely category over parts of southeast West Virginia late Sunday night as the cold front arrives. These higher chances of precipitation will translate southeast during the course of Monday with the progression of the cold front. Isolated afternoon thunderstorms will be possible across the southern half of the region. On Monday night, model guidance differs on the specifics, but the general trends is for the cold front to make limited, if any, progression south of the area. It is expected to stall and be near, or just little south of the VA/NC border. This will help keep the focus for additional scattered showers across at least the southern half of the area during the night. An approaching shortwave trough will start to slowly buckle the front northward again as a warm front late Monday night, plus added additional instability to western sections of the area. Temperatures during this portion of the forecast will average a little over ten degrees above normal. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 215 PM EDT Friday... During this part of the forecast, there will be multiple opportunities for precipitation as the area will reside with a progressive pattern with a number of disturbances passing over or near the region. On Tuesday, the front that transitioned into a warm front Monday into Monday night, will continue its very slow progression north through the area on Tuesday. Anticipate additional showers during the day with the greatest coverage across western sections. This same region has the best chance at experiencing an isolated thunderstorm or two. The warm front will move north of the area Tuesday night, allowing for a decrease in coverage of any associated showers. On Wendesday, the area will remain within a very mild and moist air mass in advance of another approaching cold front. Expect additional showers with the potential for isolated afternoon thunderstorms. Wednesday night, the cold front will continue to make greater progress toward the region from the west. Isolated to scattered showers will continue through the night. Thursday into Friday, model guidance differs on the ultimate track of this cold front. The GFS is less progressive than its European counterpart, having it finally arrive across the western portions of the region Friday afternoon. The ECMWF offers a solution that brings the front into the area Thursday night, and then stalls it over the area for Friday. So, either solutions paints a solution that either brings, or keeps showers across the area into Friday. Temperatures during this portion of the forecast will remain above normal, averaging ten to fifteen degrees above normal. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... As of 152 PM EDT Friday... Tonight, expect VFR conditions to persist after sunset as a warm front continues to inch North into the foothills of North Carolina and Virginia. Sub-VFR conditions will follow suit, as a BKN to OVC stratus deck noses South and West against the lee side of the Blue Ridge Plateau. This will bring ceilings crashing, especially at KLYH and KDAN overnight. Some BR development will also be possible in the South, mainly in areas that fall outside of the stratus deck, impacting mainly KDAN. Lower confidence with the extent of said cloud cover, which in turn impacts the presence and severity of the fog. Expect conditions to slowly improve after daybreak tomorrow, with VFR prevailing for most by mid day. The northern moving warm front could spark a few downpours and storms by the noon hour, especially over the mountainous terrain. For now, kept VCSH prevalent at KBLF, KROA, and KBCB. KLWB and the piedmont sites have lesser chances of precipitation, so have left them out for now. Plenty of uncertainty with this portion of the forecast, especially location and timing of precipitation formation, and the eventual need for TS. Will hold off on this for a future TAF issuance once newer short term model guidance arrives. Wind should remain tranquil through the period, establishing SSW to SW behind the frontal boundary. A gust or two with the heavier showers may be possible in the afternoon. Extended Aviation Discussion... The chance for precipitation comes to an end Saturday evening, with conditions returning to mostly VFR during the overnight hours. A few isolated spots may get fog early Sunday morning, especially those who received precipitation from the frontal boundary. On Sunday and Monday, the chance of showers and thunderstorms, and associated MVFR or lower ceilings and visibilities, will become more widespread in advance of an approaching cold front. This active weather pattern looks to continue through mid week before relief arrives by THU/FRI at the hands of another frontal passage. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...DS/JH NEAR TERM...AL/JH SHORT TERM...DS LONG TERM...DS AVIATION...AL/JM
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Saturday) Issued at 123 PM CDT Fri Apr 14 2017 Stratus has been slowly dissipating this afternoon as the upper trough associated with this mornings rain has moved northeast of the area. A building surface low in eastern Colorado has increased the pressure gradient over the area creating gusty southerly winds, with sites reporting gusts up to 35 mph this afternoon. These winds are expected to continue tonight and into Saturday as the surface low moves near western Kansas, and eventually pushing northeast. With continued southerly flow overnight, low temperatures stay warm in the lower 60s. GFS and HRRR give some indication for a line of overnight showers and storms moving west to east across the area generally after 9z, although lift is quite weak to get storms initiated. If some can develop, will need to watch for wind gusts possibly mixing to the surface if they can break through the low level inversion. The main feature of the period will be the potential for thunderstorm development Saturday afternoon. A cap will be in place tomorrow, although models do indicate it steadily eroding by mid to late afternoon. Storms are expected to develop ahead of the northeast to southwest oriented front by late afternoon. Between 1500-2000 J/kg of CAPE will be evaluable, although effective shear will generally be lacking with values near 25-30 knots. Steep mid level lapse rates will make large hail the main hazard of any isolated storm that initially forms in the late afternoon. Storms will may also produce locally heavy rainfall. .LONG TERM...(Saturday night through Friday) Issued at 123 PM CDT Fri Apr 14 2017 Front that comes in on Saturday at this time appears to have main impacts in the late afternoon through the evening hours. Bulk shear is lacking in directional change, so hail/wind along with training storms/heavy rainfall remain the primary concerns. EC then hangs the boundary up overnight across the southern half of the forecast area under nearly zonal flow aloft, and a secondary shortwave trof coming out of the southwest may keep the boundary in that spot for Sunday. GFS gets the front farther to our south for the afternoon, but brings convection back over the boundary Sunday evening. Potentially some reprieve on Monday if the front can get pushed southward with the convection, and convection to our south could inhibit northward development, but the GFS brings another small shortwave over the front and keeps rain chances through the day. Next system sweeps across the northern plains on Tuesday, with the EC a bit stronger with this feature, bringing more instability to the north over eastern Kansas ahead of the wave, but is again lacking in directional shear with the upper low so far to our north. As the wave migrates eastward, the EC once again lays the front across the forecast area by late Tuesday, then brings over it a series of waves through Friday morning. These three days could be the best chance for a more widespread heavy rain threat. The GFS isn`t a strong with the initial wave on Tuesday, and lifts the front back to the north on Wednesday before it is once again pushed back southward early Thursday. Much will depend on the day to day convection that occurs with these systems, the timing and location of these shortwave systems, and the placement of the surface front itself. There is enough of a signal in the guidance to be wary for heavy rainfall through the week, with chance for both convective heavy rainfall in thunderstorms, and also prolonged rainfall over the surface frontal boundary. WPC QPF totals for the 7 days still paints generally a 2-4 inch bullseye of rainfall over most of eastern Kansas for the week. Both EC and GFS bring a strong upper low out into the Central Rockies next Friday afternoon, which could bring a threat for severe storms as well as continued rain chances into next weekend. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 638 PM CDT Fri Apr 14 2017 Confidence in ceilings developing below FL030 is too low for a mention for the latter portions of the at this range, and this is the biggest change in the forecast. Winds will likely gust at times through the 02Z-14Z period with strong low level jet not far off the surface. Best chances for thunderstorms are very late in this forecast but still too low for a mention. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Heller LONG TERM...67 AVIATION...65