Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/19/18

and the previous forecast discussion is below. STP

&& .SHORT TERM...valid for Thu and Fri... Instability and low to mid-level moisture have resulted in a cumulus field over SE MT and altocu over the central zones. Radar was quiet so far this afternoon and latest HRRR still showed possible isolated showers over SE MT, but they were toned down from previous runs. Nonetheless, will keep isolated showers over the SE through 03Z, as the lingering vorticity from the system to the E departs the area. On Thursday, weak jet divergence will push N into the region as an upper low pushes E toward the four- corners region. Other than the upper-level lift, some difluence will move into the SW mountains, bringing a slight chance of afternoon showers. As the low continues moving E Thursday night, moisture will increase ahead of the low over the forecast area. A slight chance for mountain showers will translate E overnight into SE MT/Sheridan County WY. Temperatures in the low to mid 30s will support snow mixing with the rain showers. Vorticity spokes N of the low will provide some lift to the area on Friday, while jet divergence affects the SE zones. Chances for mainly rain showers will continue over the SE part of the area and will decrease from N to S during the day. The system and it`s forcing will continue moving E Fri. night and chances for showers will decrease over the SE. Temperatures each day will average in the 50s. Arthur .LONG TERM...valid for Sat...Sun...Mon...Tue...Wed... No significant changes in the extended forecast period. Saturday continues to look dry,with ridging work in. Saturday appears to be the warmest day with highs up into the 60s. Sunday still has a weak cold front moving through the region. so far this really does not amount to much more than a bit of a cool off, as best energy stays north. Another lobe of energy rotates into the region Sunday evening/night depending on your preferred model. Timing varies by about 12hrs between the GFS and ECMWF, with ECMWF running slower. That said, the track and progged period of heavier precip does appear pretty consistent, bringing best accumulations along southern tier of the CWA with lesser amounts further north. Have continued with some chance PoPs from Sunday evening into Tuesday morning to address potential of both models. Coolest day at this point appears to be Monday as precip is crossing the region. Ridging returns following this system, beginning either Monday night or Tuesday afternoon. This points to another round of seasonally warm, and generally dry conditions to end the forecast period. AAG && .AVIATION... Expect VFR conditions to prevail through tonight. An isolated shower with brief MVFR conditions is possible near KBHK through this evening. LLWS is possible near KSHR after 12z Thursday. RMS && .PRELIMINARY POINT TEMP/POPS... Thu Fri Sat Sun Mon Tue Wed ----------------------------------------------------------- BIL 034/058 036/057 035/069 036/063 035/057 033/066 034/068 01/B 11/B 10/U 11/B 34/W 32/W 11/B LVM 030/055 032/060 033/073 035/066 033/056 030/065 032/070 01/E 21/U 01/U 22/W 34/W 32/W 21/B HDN 032/059 035/057 034/067 034/063 034/057 032/066 031/069 00/B 22/W 10/U 11/B 44/W 32/W 11/B MLS 033/058 036/058 034/066 035/061 035/057 033/063 032/068 21/B 22/W 10/U 11/B 23/W 21/U 11/U 4BQ 031/056 036/054 034/065 035/061 036/054 032/061 030/065 10/B 22/W 20/U 11/B 44/W 31/B 11/B BHK 029/052 034/050 034/062 037/059 034/057 031/058 031/062 21/B 22/W 10/B 11/B 24/W 21/U 11/U SHR 029/060 034/055 032/071 034/069 035/054 031/065 030/068 00/B 23/W 20/U 11/B 34/W 42/W 11/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$
Area Forecast Discussion
National Weather Service Louisville KY
914 PM EDT Wed Apr 18 2018 ...Forecast Update... .Forecast Update... Issued at 910 PM EDT Wed Apr 18 2018 As of 9 pm EDT, radar shows the line of showers from near Lexington southwest to Hodgenville, moving quickly east. Highest gusts reported across the area with its passage has been 48 mph at SDF with several 40-45 mph gusts across southern IN and north central KY. Timing the line puts it through the rest of the forecast area between 10-11 pm EDT. A few rumbles of thunder remain possible in addition to the gusty winds. In its wake, expect a sharp temperature drop along with gusts 30-40 mph through the rest of the evening and into the first part of the overnight. Upstream gusts across southwest IN and southern IL have been 35-45 mph. As a result, no changes made to the Wind Advisory at this time. After some clearing, clouds will fill back in overnight with a low stratus deck that will likely persist through Thursday morning across southern IN and north central KY. Lows tonight will be in the upper 30s to around 40 degrees. Issued at 630 PM EDT Wed Apr 18 2018 Line of low-topped showers has developed across southern Indiana and and extreme north central Kentucky. It formed in an area of higher dewpoints where the recent SPC mesoanalysis shows a bubble of 500 J/kg SB CAPE. It`s racing across the area in a higher shear environment so the main concern is gusty winds mixing down over the next few hours. So far however wind gusts have remained at or below 40 mph. Recent HRRR and other hi-res models handling this line fairly well. Adjusted hourly PoPs to match reality and to extrapolate the line through the evening hours. Minor other adjustments were made. && .Short Term...(This evening through Thursday night) Issued at 315 PM EDT Wed Apr 18 2018 ...Strong Winds and Gusty Showers Through This Evening... Strong and fast-moving sfc low has filled in a little bit, now 1004mb over west-central Indiana. Main challenge through about midnight tonight will be precip chances and wind potential. Very high-momentum air is available aloft as the closed upper low makes its way across Iowa and into northern Illinois. Starting to see wind gusts around 30 mph already, and these winds will continue to ramp up as the low passes to our north and its trailing cold front drops in. Deep moisture has so far been unavailable to generate precip, but dewpoints over Kentucky have risen solidly into the 50s. Expect to have some shallow scattered showers develop later this afternoon through about mid-evening as the front pushes in. QPF is very light and convection will be too shallow for any thunder, but these could get quite gusty. Wind Advisory is already in effect for widespread recurring 40 mph gusts, and any showers could mix down localized 50 mph gusts. Steep low-level lapse rates in the post-frontal cold advection will keep the gusts up around 40 mph through about midnight. Valid time of the wind advisory looks good. Precip ends and winds slowly diminish after midnight, and Thursday will be as much below climo as today is above. Leaned on raw model consensus in the chilly NW flow and substantial cloud cover, which will limit max temps to lower/mid 50s. Another frost/freeze on tap for Thursday night into Friday morning, as the Bluegrass region looks to bottom out around 29-30 degrees. Recent cold nights have not seen quite the temp crash advertised in the models, and we don`t have to miss by much to avoid a freeze, so will hold off on any Freeze Watch for now. However, widespread frost is possible throughout the area. .Long Term...(Friday through Wednesday) Issued at 325 PM EDT Wed Apr 18 2018 Sfc and upper ridging will dominate through the weekend, with the upper low trying to come out of the Plains remaining well suppressed to the south. Temps will run on the low side of climo with no sensible weather impacts beyond increasing mid/high clouds on Saturday. Early next week, the upper low tries to lift into the Tennessee Valley, so precip chances will be on the increase as lobes of vorticity pinwheel around the closed low. Expect plenty of cloud cover and off and on precip chances, with temps close to normal for late April. && .Aviation...(00Z TAF Issuance) Issued at 740 PM EDT Wed Apr 18 2018 The main concern for this TAF period will be the winds as a cold front and scattered showers will move through now through 2Z. Behind the front, winds will shift to WNW. Guidance shows some enhanced wind gusts right behind this front, particularly at SDF, HNB, and LEX. After 03-06Z winds will come down a bit, but still be quite gusty through the remainder of the overnight hours. A stratus deck will then build in tomorrow morning with MVFR ceilings likely. Conditions are expected to improve to VFR by tomorrow afternoon with wind gusts subsiding as well. . && .LMK WATCHES/WARNINGS/ADVISORIES... IN...Wind Advisory until 2 AM EDT /1 AM CDT/ Thursday for INZ076>079- 083-084-089>092. KY...Wind Advisory until 2 AM EDT /1 AM CDT/ Thursday for KYZ023>043- 045>049-053>057-066-067-078-082. && $$ Update...ZT Short Term...RAS Long Term...RAS Aviation...AMS
Area Forecast Discussion
National Weather Service San Francisco Bay Area
901 PM PDT Wed Apr 18 2018 .SYNOPSIS...A fast-moving weather system will move across the southern coastal waters tonight bringing a chance of rain mainly for the southern portions of the Central Coast. A warming trend and dry weather conditions are expected late in the week and through the upcoming weekend. && of 9:00 PM PDT Wednesday...The low pressure system we have been tracking is localted 150 miles west of San Francisco and is moving SE at 30 kts. The clouds shield associated with the low has also tracked SE nearly parallel to the coast. It now appears the SFO Bay Area will miss out completely on the rain. The Santa Cruz mountains also looks less likely to get any rain as well as the interior of Monterey and San Benito counties. The MRY Bay Area and Big Sur coast still have a chance of getting the fringes of the rain and even that is in question. Will continue to monitor the progress of the low pressure system. A couple of lightning strikes were reported over the outer waters so have included a slight chance of thunderstorms in the southern coastal waters but not over land. The system will quickly move into southern California early Thursday morning. Dry conditions with slightly warmer temperatures are expected for Thursday. Surface high builds off the California coast and ridges into the Pacific Northwest Thursday night and Friday bringing a light offshore flow while an upper level ridge moves over the western states. Temperatures will warm up more significantly Friday and Saturday with highs getting into the mid 80s in the warmest inland locations. This weather pattern then persists into the first part of next week. && .AVIATION...As of 5:08 PM PDT Wednesday...For 00z tafs. Mid and high cloud deck is now moving east with vfr skies over the terminals. Incoming shortwave now expected to mainly impact areas from kmry southward overnight. Some ifr cigs possible early Thursday morning, then clearing trend by late morning. Vicinity of KSFO...Forecast vfr skies this evening and overnight. Might be some lingering ifr cigs early Thursday morning then rapid clearing with increasing wnw winds Thursday afternoon. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...Latest hrrr model runs only brush kmry/ksns with -shra overnight, with latest trends keeping precip just west over the ocean. VFR conditions this evening with possible showers around 04z. Then some possible lingering low clouds early Thursday morning before rapid clearing and vfr skies Thursday afternoon. && of 3:00 PM PDT Wednesday...A storm system will sweep through the waters later today and tonight, bringing showers and possibly a thunderstorm. Winds will increase in the wake of the cold front and become northwest by Thursday morning. A moderate northwest swell train will prevail. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm from 3 AM SCA...Pt Arena to Pigeon Pt 10-60 nm from 3 AM && $$ PUBLIC FORECAST: W Pi AVIATION: RWW MARINE: DRP Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service New York NY
1059 PM EDT Wed Apr 18 2018 .SYNOPSIS... Low pressure tracks across the Ohio Valley this evening and to just south of Long Island on Thursday. The deepening low then quickly exits into the Canadian Maritimes Thursday night through Friday. High pressure builds through the weekend and into early next week. Unsettled weather may return by the middle of next week as low pressure approaches. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Quick updated to adjust short term temperatures and dew points, as dew points continue to fall. HRRR slower with the onset of precipitation and lowered probabilities, especially eastern zones, through 07Z. Dew points have mixed out this evening, and were adjusted down into early this evening. After 00Z dew points will then begin to climb in the warm air advection and moisture advection ahead of an approaching shortwave. With increasing clouds and precipitation onset after 06Z, and continued warm advection, temperatures look to hold nearly steady, and may even rise. Made a minor adjustment upward for overnight lows. Profiles inland saturated and below freezing above the surface. There may be some wet snow mixed with the rain across the higher elevations of Orange and Putnam counties, and added a rain/snow mix. Then mid and upper levels dry after 12Z and precipitation transitions to all rain. On the heels of a departing upper low across eastern Canada, a vigorous shortwave trough at the base of the upper trough will pivot across the area into Thursday. This will send low pressure over the Ohio Valley east tonight and then to the south of the area Thursday morning. Warm advection ahead of the system will result in increasing clouds this evening with light rain developing from west to east after midnight. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Periods of light rain will continue for much of the day Thursday with the highest probability being across the interior where the better thermal forcing will prevail. As low pressure pulls to the east by afternoon, wraparound light rain will continue, tapering off from west to east during the late afternoon/early evening hours. Rainfall totals for the event will range from about a tenth to a quarter inch, with the highest amounts across the interior. As the precipitation winds down, there is the possibility that a few snow flakes could mix in. It will be another unseasonably cold day with temperatures remaining in the 40s, and then dropping into the 30s Thursday night. Gusty NW winds up to 30 mph will develop behind the low late Thursday afternoon/early evening and continue through the overnight. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Generally tranquil weather is expected during this time frame. Departing trough to the northeast makes slow progress, with upper level NW flow continuing across the northeast through the weekend. Ridge builds across the upper midwest and Great Lakes region, to the north of southern stream shortwave that passes from the Rockies through the southern states. The southern stream shortwave, along with northern stream energy will likely make progress toward the east coast Tuesday-Wednesday, potentially resulting in unsettled weather by mid week next week. Otherwise, dry conditions along with slightly below normal temperatures are anticipated. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... A wave of low pressure approaches tonight, and passes south of Long Island Thursday morning, then strengthens as it continues out to sea during the afternoon. VFR through at least 06z. Clouds thicken and lower overnight. There is some uncertainty in when conds drop to MVFR, however with guidance indicating pcpn slightly delayed from earlier thinking have sided with the hi-res solutions and delayed MVFR conds as well. Only have conds dropping to IFR at KHPN/KSWF/KBDR/KGON where confidence is a bit higher, although it is a possibility at remaining terminals for at least a couple of hours Thu. Conds improve back to VFR late from W to E. P-type could be an issue at KSWF. Soundings indicate a few hours of SN or RASN until mid levels dry out early Thu morning. Light and vrb winds overnight, pick up out of the E-NE 5-10kt towards morning. As the low passes to the south and strengthens while departing, winds will back to the N then NW and increase to 10-20g20-30kt in the late aftn/eve. .OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY... Thursday night-Friday...VFR. NW winds G20-30KT, mainly Thu eve and after sunrise Fri. .Saturday-Monday...VFR. && .MARINE... Wind and seas will subside tonight as low pressure approaches from the Ohio Valley and passes just south of the waters Thursday morning. As the low deepens heading up into the Canadian Maritimes Thursday night into Friday, near gale force gusts will develop on the waters Thursday evening. A moderate northwest pressure gradient should allow for SCA gusts 25- 30 kt to continue over the waters on Friday, before diminishing Friday night. A small craft advisory has been posted for all the waters beginning Thursday night and continuing into Friday morning, except through Friday afternoon east of Moriches Inlet. The pressure gradient is forecast to relax over the waters this weekend, becoming light by Saturday night. As a result, sub Small Craft Advisory conditions are forecast over the waters around Long Island Saturday-Monday as high pressure builds closer. && .HYDROLOGY... Rain amounts below a half inch are expected tonight through Thursday evening with no hydrologic impacts anticipated. Dry weather follows thereafter. There is the potential for significant rainfall mid week next week. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off the air. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory from 6 PM Thursday to 6 AM EDT Friday for ANZ330-335-338-340-345. Small Craft Advisory from 6 PM Thursday to noon EDT Friday for ANZ353-355. Small Craft Advisory from 6 PM Thursday to 6 PM EDT Friday for ANZ350. && $$
Area Forecast Discussion
National Weather Service Mount Holly NJ
927 PM EDT Wed Apr 18 2018 .SYNOPSIS... A area of low pressure will move across the area tonight into Thursday, along with its associated occluded, warm, and cold fronts. This low will drift into the Canadian Maritimes through Friday, which will keep northwest flow across the area with a couple of dry surface troughs moving across the east coast. High pressure will build into the Mid Atlantic and Northeast Saturday through Sunday, before moving offshore Monday into Tuesday. A coastal low may move north along the coast and affect the area during the middle of next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 915 pm update: Made some adjustments to temperatures and dew points overnight, with the former being too warm and the latter being too cold during the evening hours. Minimum temperatures were lowered a couple degrees in spots based on input from high-resolution guidance, though tempered this to some degree given increasing cloud cover. Tweaked PoPs some more, with continued trends of the precipitation falling primarily north of the I-276/I-195 corridors. Thus, I sharpened the PoP gradient rather considerably overnight. 700 pm update: Main changes to the forecast were to modify PoPs tonight based on latest hi-res guidance, which generally indicate a period of light rain/sprinkles/showers from 03Z to 10Z generally north of the I-276/I-195 corridors. The HRRR suggests a briefer period of rain but potentially with heavier rainfall rates, whereas the WRF-ARW/NMM and NAM Nest suggest a longer duration of lighter precipitation. My thinking is that the briefer duration of the precipitation is more reasonable (especially given upstream radar trends), though I am not quite convinced of the wetter solutions yet (despite the rather potent look to the vort max, along with the close proximity of the surface low). Increased PoPs slightly to the north of the I-276/I-195 corridors, but reduced them to the south (and remaining unmentionable south of an Easton, MD, to Wildwood, NJ, line). Other main change was to include some chances for (light) snow to mix in with the rain late tonight in the Poconos (and far northwest New Jersey), where temperatures will become cold enough (and profiles will cool sufficiently) for the white stuff to show up. Will update storm total snow grids accordingly, though amounts are expected to be very light (and generally only at the highest elevations). Previous discussion... Surface low pressure will approach the region from the west tonight, moving into our area late tonight. Cloud cover will increase quickly tonight as the low moves closer to the area. Some light rain will fall, in advance of the approaching low but amounts are expected to remain light, with southern areas likely remaining dry through daybreak. Overnight lows will drop into the mid to upper 30s across the northern zones to mid to upper 40s across the southern zones. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... 915 pm update: Lowered temperatures in the northern CWA some more and increased PoPs north of the I-76 corridor tomorrow, as there is an increasing signal for scattered to numerous showers tied to the cold pocket of air aloft collocated with the main trough moving through. Think the colder model simulations make more physical sense given the expected regime (and cloud cover). 700 pm update: As the surface low moves offshore tomorrow morning, should see a brief break in precipitation before instability showers/sprinkles move in during the late morning and afternoon as the main trough/vort max move(s) into the region. Precipitation amounts should be very light (and will likely be a mix of rain and snow in the Poconos), but would not be surprised to see some snowflakes mix in with the showers farther southeast. Trended forecast in that direction a little bit, but not too much given the expected temperatures/low-level thermal profiles. Tweaked PoPs to match the timing of the instability showers, as depicted by the NAM Nest, WRF-ARW/NMM, and HREF. Also slowed the onset of the stronger winds by a couple of hours, but did not change the magnitudes that much given the model-derived mixing profiles. Previous discussion... Low pressure will cross the region tomorrow, dragging a cold front through during the late morning/early afternoon. Some light rain will fall across the region as the low crosses the area. Amounts will be fairly light, especially across southern areas, with only a tenth of an inch or less expected. As temperatures cool across the higher terrain, a few flurries or light snow showers may occur as the precipitation starts to come to an end toward Thursday evening. Extensive cloud cover across the northern half of the forecast area will keep much cooler and only into the upper 30s to mid to upper 40s. Once you get down towards Philadelphia and points south, skies should see a few breaks. Highs into the upper 50s to lower 60s are expected. Even with the sun peeking out, it will feel cooler through the day as the winds will really start to ramp up by late morning/early afternoon. Winds will be our of the north to northwest at around 15 to 25 mph with gusts up to 35 mph possible. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... A quiet start to the extended forecast for the end of the week, through this weekend, into early next week. A return of unsettled weather is possible by the middle to end of next week. On Thursday night, the low pressure that affects the area during the day will continue to move northward into the Canadian Maritimes. Most of any precipitation associated with the low will move to our north with the low pressure. However, there could continue to be some snow showers across the higher elevations, especially during the evening hours as the low-mid level lapse rates may be high enough to interact with some left over moisture and the passing short wave. These showers will dissipate through the night into Friday morning as the moisture dissipates across the area. On Friday, the low will remain across the Canadian Maritimes, while surface trough will likely cross the area. The trough will be dry, and only present a shift in wind direction and possibly some cloud cover, as it will likely not having much of an airmass change. Winds during the day will be generally out of the northwest, and gust 25- 30 mph, occasionally up to 35 mph at times. Dry and breezy conditions will continue into Friday night as well. On Saturday, dry conditions will continue as another dry surface trough will move across the area, before high pressure builds into the area overnight. Winds will gust around 20 mph at times, but it will not be as windy as Friday. High pressure builds across the Mid Atlantic and northeast Sunday, before moving offshore my Monday. Dry conditions will continue for Sunday and Monday. As we move into Tuesday and Wednesday of next week, a coastal low is forecast to lift northward along the east coast. There is timing differences between the GFS, ECMWF, and Canadian. With the timing differences, there is the potential for rainfall starting as early as Tuesday, with the most likely period looking to be Wednesday Wednesday night. Temperatures across the area are forecast to be above freezing, so the precipitation would be all rain. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Tonight...VFR to start with, but CIGs are expected to develop rapidly and descend after 03Z. By 09Z, may see RDG/ABE flirt with MVFR criteria. Light rain or showers are forecast near/north of RDG/ABE/TTN, but may have a difficult time reaching PNE/PHL/ILG and are not expected to affect MIV/ACY. Low VFR to MVFR expected at most sites by daybreak. Winds will become light/variable quickly this evening. Moderate confidence. Thursday...Low VFR to MVFR conditions are anticipated at most sites, especially during the morning, as drizzle/patchy fog may occur near RDG/ABE/TTN and light showers subsequently move through the Philly terminals northward and westward through mid afternoon. CIGs will likely rise a little bit during the afternoon as winds become westerly/northwesterly and gusty by late morning and continuing during the afternoon (10-20 kts with gusts 25-30+ kts). Moderate confidence. OUTLOOK... Thursday night...MVFR conditions possible early, before improving to VFR overnight. Gusty northwest winds 20-30 knots. Friday-Monday...VFR through the period. Gusty northwest winds 20-30 knots Friday; 20-25 knots Friday night; and 15-20 knots Saturday. && .MARINE... Gale watch for southern NJ/DE Atlantic coastal waters and for Delaware Bay was upgraded to a gale warning from 2 pm Thursday to 8 am Friday. Gale watch remains in effect for the northern/central NJ waters, where confidence is a little lower on gusts meeting criteria (and potentially for a little bit later of an onset, given the latest model guidance). Previous discussion... Tonight...Quiet conditions on the area waters with southerly winds around 10 to 15 knots and seas around 2 to 4 feet. Thursday...Winds will pick up out of the northwest on Thursday and become particularly gusty during the afternoon and evening. Soundings show a strong, deep layer of 35+ knots over the area waters and mixing should be fairly efficient by the afternoon. Sustained winds of 15 to 25 knots with gusts up to 35 knots. Seas will also increase to around 4 to 5 feet by Thursday afternoon. OUTLOOK... Thursday night...Winds could gust up to 35 knots through the night. Friday-Friday night...Small Craft Advisory conditions likely. Saturday-Monday...Sub Small Craft Advisory conditions exected. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Gale Watch from Thursday afternoon through Friday morning for ANZ450>452. Gale Warning from 2 PM Thursday to 8 AM EDT Friday for ANZ430- 431-453>455. && $$ Synopsis...Robertson Near Term...CMS/Meola Short Term...CMS/Meola Long Term...Robertson Aviation...CMS/Robertson/Meola Marine...CMS/Robertson/Meola
Area Forecast Discussion
National Weather Service Blacksburg VA
944 PM EDT Wed Apr 18 2018 .SYNOPSIS... Low pressure will move through the middle Atlantic region and push a cold front through the Appalachians and central mid Atlantic region. This will bring very windy conditions, along with much colder temperatures, along with some showers west of the Blue Ridge and even some west snow for the higher elevations. High pressure then builds in with fair conditions and slightly warmer temperatures into the weekend. && .NEAR TERM /THROUGH THURSDAY/... As of 944 PM EDT Wednesday... Modified temperatures this evening into tonight utilizing the latest surface obs, their trends and shaped towards GLAMP. Made some minor changes in pops and weather blending in the HRRR. Timing of showers by 06z in the west, stills looks reasonable. However, convection will weaken as it moves towards our forecast area. Wind advisory on track for overnight into Thursday along and west of the BLue Ridge. Post frontal winds will be gusty supported by strong cold advection. As of 744 PM EDT WEdnesday... Wind advisory for post frontal winds from the Blue Ridge westward looks good. Made some minor adjustments in temperatures for this evening into tonight. Convection along the cold front appears limited this evening. However, HRRR and Highres models still support current pops in the west. The best chances are along the far west mountains with upslope enhancement late tonight into Thursday. As of 225 PM EDT Wednesday... Low pressure will move through the middle Atlantic region and push a cold front through the Appalachians and central mid Atlantic region. This will bring an abrupt end to our one day of spring as much colder air moves in on strong gusty northwest winds. Expect rain showers with the front west of the Blue Ridge to transition to upslope rain/snow showers on Thursday with some minor snow accumulation for the higher elevations. The upslope precipitation will be decreasing during Thursday afternoon. The winds behind the front will become quite strong as cold air advection creates efficient downward momentum transfer with gusts around 50MPH at the higher elevations from the Blue Ridge westward starting around Midnight and continuing through tomorrow. Gusts will not be quite as strong east of the Ridge and will generally wait for the arrival of netter mixing with diurnal heating by mid/late morning. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 300 PM EDT Wednesday... Models agree on continuation of stronger winds at least until midnight Thursday night, especially along the Blue Ridge as 45 kt jet shifts toward the southern Shenandoah Valley. Expect some linger flurries in western Greenbrier, then dry, sunny and cool Friday. May have some freeze issues late Thursday night but no frost as RH only recovers to 60-65 percent and winds will be blowing. Highs Friday will be in the 50s in the mountains, with even some 40s in the higher ridges of the Alleghanys, to lower to mid 60s across the foothills/piedmont. May have more of a freeze/frost issue late Friday night, especially in the southern Shenandoah Valley as winds drop off and temps drop to near freezing. No headlines at this point. Saturday, the surface high continues to build in from the Great Lakes providing sunshine and warmer highs in the 60s. Clouds increase ahead of the upper system moves into the lower MS valley. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 145 PM EDT Wednesday... Going to be wet/cool but not cold period, as upper low develops over the lower MS Valley Sunday and pushes across the northern tier of the Gulf Coast states Sunday afternoon into Tuesday. Models have trended north, but would like to see more consistency in them, as a further south track would lead to dry/cool with more sun while north would be wetter/cloudier but still a bit on the cool side. For consensus, models are showing more of cloudy pattern with threat of rain each day. As the low moves off the coast Wednesday, a northern stream front shift in from the northwest with another threat of showers. Sunday appears the drier of this period with increasing clouds. Highs will range from the mid 50s to lower 60s mountains, with mid to upper 60s in the piedmont/foothills, which is about 5 degrees below normal. Lows will be close to normal during the week with mid 30s to lower 40s west, to lower to mid 40s east. Highs Monday-Tuesday will be around 10 degrees below normal, ranging from the lower to mid 50s west, to upper 50s to lower 60s east. May be a little warmer Wednesday ahead of next front with upper 50s to lower 60s mountains, to mid to upper 60s east. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... As of 730 PM EDT Wednesday... Low pressure with a trailing cold front will move east though the Mid Atlantic region tonight into Thursday. VFR condition will continue this evening into tonight. Overnight into Thursday Taf locations west of the Blue Ridge will trend to generally MVFR, possibly IFR, as the front brings upslope showers to the region. Colder air moving in will gradually mix/change to snow showers. Don`t expect much spill over past the Ridge so will maintain a VFR forecast in the east. Conditions will become quite windy behind the front as cold air moves in and makes for efficient momentum transfer of vigorous low level winds to the surface. Expect the strong gusts to make their way east of the Blue Ridge primarily with onset of heating and better diurnal mixing. Gusts AOA 40kts can be expected along/west of the Blue Ridge, around 30kt to the east. High confidence in ceilings, visibilities and winds during the taf period. Extended Aviation Discussion... VFR returns Friday although gusty north winds to persist as high pressure slowly builds in from the northwest. Winds should diminish by Saturday with VFR ceilings and visibilities. Clouds will begin to creep back into the area on Sunday in advance of an approaching low in the Lower Mississippi River Valley. However, cigs should remain VFR while the ceiling heights lower and clouds thicken. SCT MVFR showers are possible in southern Virginia and northern North Carolina Sunday night into Monday morning. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...Wind Advisory until 6 AM EDT Friday for VAZ007-009>020-022>024. NC...Wind Advisory until 6 AM EDT Friday for NCZ001-002-018. WV...Wind Advisory until 6 AM EDT Friday for WVZ042>044-507-508. && $$ SYNOPSIS...MBS NEAR TERM...KK/MBS SHORT TERM...WP LONG TERM...WP AVIATION...AMS/KK/MBS