Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/16/19

Area Forecast Discussion
National Weather Service La Crosse WI
1100 PM CDT Fri Mar 15 2019 .SHORT TERM...(This evening through Sunday) Issued at 245 PM CDT Fri Mar 15 2019 A northwest flow pattern will keep the area mainly dry with seasonably cool temps through the weekend. Visible satellite showed diurnally driven strato developing southeastward from northern MN/WI as an upper trough rotates into the Upper Great Lakes. A few flurries/snow showers are possible with steep low level lapse rates, particularly over northern WI where RAP soundings indicate deeper low-level moisture. A few more upper level troughs will rotate southeastward on the western periphery of the longwave trough later Saturday into Sunday. Moisture will be quite limited, but some light snow showers/flurries/sprinkles are possible at times, but with minimal impacts. Temps will be on the cooler side of average through the weekend with highs in the 30s to low 40s and lows in the teens to low 20s. .LONG TERM...(Sunday night through Friday) Issued at 245 PM CDT Fri Mar 15 2019 A fairly quiet period is expected through the work week with gradually warming temps as northwest flow aloft early in the week transitions to broad upper ridging by late week. An embedded shortwave trough will slide across the area Monday night into Tuesday but the 15.12Z model suite continues to show differences with the strength/timing of the wave. The ECMWF/GEM are stronger/slower and bring some light precip to the area on Tuesday while the GFS is dry. With low confidence in the evolution of this system, kept mainly low end precip chances at this time. Generally dry weather is expected late this coming week under the influence of deep ridging. High temps will warm from the mid 30s to mid 40s on Monday to mainly 40s by mid-week, with 50s more likely by later in the week. With low temps expected to remain near or below freezing, a gradual snow melt is expected through much of next week. && .AVIATION...(For the 06z TAFS through 06Z Saturday night) Issued at 1100 PM CDT Fri Mar 15 2019 Cigs/wx/vsby: pesky low clouds still making their way southeast through the area, although have broken up quite a bit compared to earlier in the evening. Plus, VFR now. Expect to see more diminishment/exiting of the clouds overnight as low pressure cont to exit and loss of daytime heating. A few more shortwave troughs look to spin across the region for Sat afternoon-Sun. Expect periodic bkn cigs with the features - and could see a return to at least mvfr late sat night-sun. Some light snow possible mostly south of the TAF sites Sat, slightly better chances Sat night-Sun. Overall though, threats looks look, as does related vsby impacts. Winds: continue to weaken overnight, then mostly under 10kts for Sat. Direction looks to hold west/northwest. && .HYDROLOGY... Issued at 245 PM CDT Fri Mar 15 2019 Minor to major flooding continues along area Mississippi River tributaries, especially near and south of Interstate 90, with impacts to continue into the weekend. Gradual rises are expected on the Mississippi River, but flooding is not expected over the next week. With cooler, more seasonable temps into early next week, including sub-freezing temps overnight, snowmelt runoff will be more gradual over the next week. Please refer to the latest flood statements for additional details. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...JM LONG TERM...JM AVIATION...Rieck HYDROLOGY...JM
National Weather Service Binghamton NY
933 PM EDT Fri Mar 15 2019 .SYNOPSIS... A cold northwest flow will develop tonight and persist through Saturday night with on and off scattered snow showers. A weak system will move through Sunday night and Monday with another shot of light rain or snow. Dry weather expected Monday night through the middle of the week. && .NEAR TERM /THROUGH SATURDAY/... With the evening updates, precipitation chances were updated for the overnight along with a sharp temperature and cloud gradient along a cold front. Both the HRRR and RAP have been consistent in showing an area of rain and snow showers to form across the Finger Lakes just after midnight. These showers then translate southeast from the Cortland area into Delaware county by sunrise. QPF was upped slightly for the overnight in these areas with the potential for up to a half inch of snow accumulation. Modeled soundings show fairly steep low level lapse rates along with slight amounts of CAPE present. As a result, potential is present for the precipitation to become squally in nature with gusty winds and this will be watched through the overnight. The frontal boundary is still slowly moving through so the result is for these very warm temperatures along with a clear slot to hang in a little longer east of I-81 and across all of NE PA. Main concerns in the near term are focused on the receding warm temperatures this afternoon which will be replaced by much colder air later tonight and tomorrow...and the potential for a few rain showers today, mixing with snow later this evening and then scattered light snow showers through the day tomorrow. Large low pressure system continues to wrap up and lift to the ne over ern Canada this afternoon with several embedded short waves rotating around the parent low across the Great Lakes into the Northeast. The initial wave and associated surface cold front moved through the area this morning with a few light rain showers into central NY and ne PA. Weak ridging and a wedge of very deep, dry air within the flow is sliding across the region this afternoon...and causing the mostly sunny skies. The amply sun and residual warm air under a weak upper level ridge has allowed temperatures to climb into the mid 50s in the Finger Lakes and up to Oneida county...with 60s, close to 70 in the valley locations to the south and se. A secondary cold front with much colder air behind it will push through the area this evening with light rain showers on the front end, and enough cold air advection and diurnal cooling tonight through the column to mix in some snow around or just after midnight. A couple more dampened embedded waves will rotate through the broad synoptic scale trough tonight and Saturday...and help enhance some of the showers from time to time. The cold air advecting in from the nw...850mb temps around -11 deg C...combined with Lake Ontario waters around +3 deg C may also help enhance some of the showers by producing a weak amt of lake induced instability Saturday morning through the afternoon. Available moisture is expected to be limited and the depth of the mixed layer should be relatively shallow, so rain/snow showers late tonight and also straight snow showers through the day tomorrow should be generally on the light side. Snow amounts may total up to an inch in the hills south of Syracuse and over nrn Oneida county through Saturday afternoon...and less than an inch over a broad area of central and srn NY. The other concerns tonight and tomorrow will be the gusty w/nw winds and the much colder temperatures. Much of the region can expect sustained nw winds around 15 to 20 mph...and gusts 30 to 35 mph through Saturday afternoon. Temperatures tonight will fall into the upper 20s and lower 30s for most of the area...and only climb into the mid to upper 30s during the day Saturday. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... Northwest flow of moderately cold air across Lake Ontario will keep light lake effect snow showers into the area, primarily central NY into the Catskills into early Sunday. Shortwave in the northwest flow drops through Sunday night into early Monday and brings the chance of a bit more widespread but light snow to the area with very light accumulations if anything expected. Daytime temperatures Monday will probably change the snow to light rain, especially in the lower elevations and in northeast Pennsylvania. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A few lake effect snow showers are not out of the question Monday night behind the exiting system, but high pressure building in will help to dry things out for Tuesday. The ridge moves eastward out of the area Tuesday night as models continue to bring in another system for the midweek. Warmer, more moist air works in for Wednesday, with the possibility of rain/snow showers starting as early late Wednesday morning in our far western zones. Rain showers spread across the rest of the area into the afternoon. Though there is still some disagreement on the track of this system, the best window for rain/snow showers looks to be Wednesday night through Thursday morning, ahead of the cold front. A slight chance for rain showers continues Thursday afternoon with the passing frontal system, tapering off to mainly lake-effect flurries and snow showers Thursday night before high pressure takes control once again Friday into the weekend. As for temperatures, the extended will start off on the cool side with lows around 10-20F Tuesday morning and highs generally in the 30s to near 40F during the afternoon. The rest of the period turns warmer, with lows generally in the 20s to low 30s, and highs in the upper 30s to upper 40s. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... VFR conditions expected to continue through this evening at all terminals. Then a secondary cold front will bring a mix of scattered rain and snow showers, transitioning to scattered snow showers, along with MVFR ceilings after 06z for KRME, KSYR, and KITH and after 09z for KELM and KBGM. Coverage of snow showers at KELM and KBGM looks limited and therefore left this out of this TAF set. KAVP is expected to remain VFR during this time. Some snow squalls are possible at ITH between 06Z and 09Z, so included a TEMPO group there for brief IFR conditions. After somewhat calmer winds this evening, winds will be increasing through the overnight and into Saturday (west winds 15-25kts with gusts 25-30kts possible). Outlook... Saturday night...Possible restrictions in scattered snow showers across mainly the NY terminals. Sunday...Lingering early morning flurries, then becoming VFR. Sunday night and Monday...Possible restrictions in snow showers. Tuesday...VFR. Wednesday...Some restrictions possible in scattered rain and/or snow showers. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...BJT NEAR TERM...BJT/MWG SHORT TERM...DGM LONG TERM...HLC AVIATION...BJG
Area Forecast Discussion
National Weather Service Boston/Norton MA
946 PM EDT Fri Mar 15 2019 .SYNOPSIS... A cold front moves across southern New England tonight. Locally heavy rain will be possible this evening near the south coast. Behind the front, windy and cooler conditions are expected for Saturday, then even colder Sunday into the middle of next week as high pressure builds into our region. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... HRRR, NationalBlend and time-lagged ensemble of HRRR runs continued to show very good handing of observed radar trends. Continued to use these guidance sources to refine the rainfall timing and location through at least midnight. Radar still estimating cell motion between 55-65 mph. This movement is great for preventing too much rain from falling in one location too quickly. Still monitoring for training cells. Even so, total rainfall should be readily handled. Will need to consider snow melt, too. If any flooding occurs, it should be of the poor- drainage/nuisance variety. A cold front had yet to move into the western portion of southern New England. Still expecting this front to reach the east coast between 2-4 AM. Much drier air should then start to overspread our region. Brought the forecast back in line with observed trends. Previous Discussion... The primary concern this evening will be convective potential across southern New England. As we progress well past sunset, expecting conditions to only become more unfavorable with time. However, this is looking like a high shear/low instability scenario, at best. After looking at the latest high resolution guidance, am thinking there is a risk for an isolated thunderstorm or two, but very little chance for sever weather. Really like the idea present by the latest NationalBlend and HRRR time-lag ensemble guidance. It matched up well with observed radar trends. Main changes this evening were to update timing and location of rainfall chances. Estimated storm motion is in the 45-55 kt range, so the timing may still be off at any given location. The greatest risk for rainfall will be across northern CT, RI and SE MA this evening. Expecting clearing to develop quickly behind a cold front after midnight, or so. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... Saturday... Cold front moves offshore, with cold air advection, steep low level lapse rates accompanied by a tight pressure gradient. This will bring the potential for strong, gusty west winds. Wind gusts of 30 to 40 mph are likely, with the strongest gusts over the interior higher terrain. There is a low risk that gusts could reach wind advisory thresholds if we can mix the H850 winds down to the surface. Not enough confidence at this time to go with an Advisory. Otherwise, expect a mix of sun and diurnal cumulus as mid level trough moves into New England. Given strong cold advection, only minor temp recovery expected, with high temps mostly in the mid/upper 40s, but colder over higher terrain. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... Highlights ... * Colder with below normal temps Sunday-Tuesday * Low risk of light rain/snow Monday * Warming trend late next week Not much change from this time yesterday. Our region will be on the periphery of mid level trough persisting through most of this portion of the forecast. Models are in good overall agreement through Monday, with the detail differences becoming more significant after that point. Will continue to favor a consensus approach to smooth over the less predictable details, mainly due to timing issues of various smaller features. Temperature-wise, expecting below normal temperatures through Tuesday night, then temperatures should become near to above normal through the end of the next work week. Precipitation-wise, mainly dry weather expected. There is a low risk for some light rain, or even some snow, towards the south coast Sunday night into Monday as a clipper-like low pressure passes by to our south. Little to no snow accumulation is expected, especially when falling during the daylight hours, when rain is much more likely. Have little confidence in the timing of a possible front later next week, which would provide our other chance for some light precipitation. Same scenario, typical for this time of year, where some light snow or rain is possible, especially if the precipitation falls at night. Not looking like major weather-makers in either case. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Saturday/... Tonight...Moderate confidence. Widely variable conditions, from VFR generally along and north of the Mass Pike, to IFR in stratus and fog towards KACK and the south coast. mainly MVFR in widespread SHRA and isolated TSRA. Cold frontal passage W-E brings wind shift from SW to W, and conditions improving to VFR. Last locale to improve to VFR Cape/Islands where IFR may linger until near 12Z Sat. Strong winds just off the deck will continue to generate LLWS towards the south coast of New England. Saturday...High confidence. Mainly VFR with SCT-BKN CIGS 4-6kft developing. W wind gusts 25-35 kt developing, strongest over northern MA/interior higher terrain. KBOS Terminal...Moderate confidence in TAF, mainly due to timing issues for convection overnight. KBDL Terminal...Moderate confidence in TAF, mainly due to timing issues for convection overnight. Outlook /Saturday Night through Wednesday/... Saturday Night through Sunday: VFR. Breezy. Sunday Night through Wednesday: VFR. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Saturday/...High confidence. Tonight and Saturday... Replaced last of the Gale Warnings with Small Craft Advisories overnight. SW gusts 25 to 30 kts expected to become west with a cold frontal passage late tonight. Then W gusts increase during Saturday behind the cold front. Seas 5 to 8 ft tonight, lingering on Sat. Reduced vsbys this evening in showers, mainly across the southern waters. Then dry during Sat. Outlook /Saturday Night through Wednesday/... Saturday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Sunday: Winds less than 25 kt. Local rough seas. Sunday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Monday: Winds less than 25 kt. Slight chance of rain, slight chance of snow. Monday Night: Winds less than 25 kt. Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft. Tuesday Night: Winds less than 25 kt. Wednesday: Winds less than 25 kt. Seas locally approaching 5 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 6 AM EDT Sunday for ANZ232>235-237- 250-254>256. Small Craft Advisory until 2 AM EDT Sunday for ANZ230. Small Craft Advisory until 5 AM EDT Sunday for ANZ231-251. Small Craft Advisory until 6 PM EDT Saturday for ANZ236. && $$ SYNOPSIS...Belk/NMB NEAR TERM...Belk/NMB SHORT TERM...NMB LONG TERM...Belk AVIATION...Belk/NMB MARINE...Belk/NMB
Area Forecast Discussion
National Weather Service Blacksburg VA
855 PM EDT Fri Mar 15 2019 .SYNOPSIS... A cold front will pass east and offshore overnight. High pressure will follow the front bringing more seasonable temperatures along with drier weather this weekend. Another mainly dry cold front crosses the area by early Monday. && .NEAR TERM /THROUGH SATURDAY/... As of 845 PM EDT Friday... Surface cold front remains quite slow to cross the far eastern sections this evening as still need to wait on another passing shortwave aloft to give it a better boot to the east. Appears this should happen by midnight with much drier air to the west poised to push across the piedmont through the early morning hours. However with the slowing of the boundary, have seen the surge of strong winds decrease with sunset and will now take the upstream cold advection and subsidence to get the gradient going again. Best jet aloft also progged around or just after midnight into dawn Saturday, although still some uncertainty in just how much wind will mix down per high inversion off the evening RNK raob and modified cold air for this time of year. Thus lowered speeds/gusts over the next few hours to match obs and the latest HRRR which shows the stronger gusts in the pre-dawn hours of Saturday. Otherwise removed pops across the east with the passage of the front, while also delaying any low pop snow showers with increasing upslope moisture over the northwest given such a lingering warm boundary layer. Also bumped up lows espcly Blue Ridge east as will take until late tonight for the 850 mb temp gradient to reach eastern sections. Therefore looking at a range from around 30 far west to the low/mid 40s east. Update as of 455 PM EDT Friday... Doing a quick update to include both Tazewell and Mercer counties into the wind advisory while starting the advisory now given ongoing wind speeds where deeper mixing has developed over the west. Actual 85h front is still lagging back which will keep the wind gradient going overnight into Saturday. Also tweaked pops down over the southeast where coverage has faded into lighter showers. No other changes for now. Previous discussion as of 215 PM EDT Friday... Upper trough axis still west of the forecast area over the MS Valley this afternoon. Surface front has made it to the I-81 corridor in Virginia. Convection has fired up ahead of the front is a limited instability axis, but with decent shear from Staunton River State Park, VA southwest to the eastern Triad/western Triangle area of NC. High-res models paint a slower movement of the front allowing for another wave aloft to redevelop a band of showers/storms behind the first one by 5pm in southside VA into the NW NC piedmont. However, having been worked over think the better threat of storms will continue to work east and out of the forecast area before dusk, so basically between now and 6pm is when the stronger storm threat is expected, and may exit sooner based on radar trends. We turn next to the winds behind the front. Strong pressure rises, a 40-50kt low level jet and strong cold advection should push wind gusts to advisory levels across the Blue Ridge of VA and NC into the Alleghanys. Main surge of winds should occur this evening til about 4am, then a secondary surge possible around 12z Saturday. Given this will hoist a wind advisory for said areas including the New River Valley to Smyth County VA from 6pm this evening til 11am Sat. Otherwise, should see clearing trend from west to east this afternoon/evening though some models especially the 12z NAM allow for shield of high clouds in the southeast this evening. Lower clouds with upslope will bring snow showers/flurries to the mountains of WV and shallow moist layer will limit accumulations to one inch or less in western Greenbrier. Temps will drop back to normal for lows tonight, ranging from the upper 20s to lower 30s mountains, to upper 30s to lower 40s east. Low clouds will erode in the west Sat morning, with plenty of sunshine expected. A secondary dry front works across in the afternoon, but not any moisture expected. Keeping temps slightly below normal with mid to upper 40s in the mountains, to mid to upper 50s east. Confidence is at or above average for winds, and above average for the rest of the forecast. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... As of 1215 PM EDT Friday... Drier and colder air will continue to advect into the region on northwest winds all while the center of surface high pressure moves eastward from the Arklatex region. Higher in the atmosphere, a broad upper level trough will remain parked over southeast Canada with its trailing trough axis extended into the Great Lakes region. Within this broader flow models depict weak shortwave troughs swinging through the Ohio River Valley then into PA/NJ. However, each model differs on timing and any potential sensible weather for any part of our forecast area with these features. Currently the best consensus of solutions points towards Sunday night into early Monday as the time frame for the greatest potential for some isolated to scattered rain/snow showers across parts of southeast West Virginia and neighboring counties of southwest Virginia. Any accumulations are expected to be around or less than one inch over western Greenbrier County, WV. Low temperatures during this portion of the forecast will range form the mid 20s to near 30 degrees across the mountains with upper 20 to mid 30s across the Piedmont. High temperatures will range from the mid 40s to upper 40s across the mountains to around 50 degrees to the mid 50s across the Piedmont. Forecast confidence during this portion of the forecast is moderate to high with quantity, location, and timing of the light snow across southeast West Virginia the biggest question. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 100 PM EDT Friday... The area will continue within a relatively dry period into at least Tuesday and Wednesday as the center of surface high pressure arrives over the region. Wednesday night into Thursday, our weather picture changes. We will be watching for a cold front to cross the area. Guidance varies on the amount of associated moisture and sensible weather for our area; however, all solutions are fairly uniform on the timing. Any weather will likely be confined to the upslope regions of southeast West Virginia south into the Northern Mountains of north Carolina as the prevailing flow throughout the column is expected to be nearly unidirectional with no additional moisture added to this feature from either the Gulf of Mexico or the Atlantic Ocean. Winds will become gusty behind the front for Thursday night and Friday thanks to a tightening pressure gradient between a building upper ridge across the Mississippi Valley and the persistent upper trough over southeast Canada. Low temperatures during this portion of the forecast will range from around 30 to the mid 30s across the mountains to the lower 30s to the upper 30s across the Piedmont. Forecast confidence during this portion of the forecast is moderate. The biggest question is the extent and coverage of light snow Wednesday night into Thursday. Also, whether or not the western flanks of a coastal system will bring some light precipitation into eastern parts of the area on Thursday is another question. Currently our forecast says no to that potential. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... As of 645 PM EDT Friday... Surface cold front currently sliding off the Blue Ridge should finally cross eastern sections early this evening allowing for a period of improving conditions back to VFR across the region into tonight. However will see west winds pick up as drier air surges in behind the boundary with gusts to 30-40 kts possible overnight along the western ridges, and to 25-30 kts out east this evening. A strong low level jet and cold advection with decent pressure rises will bring gusts up to 40 kts along the Blue Ridge possibly impacting KROA/KBCB in the 03-09z time frame. As colder air aloft under the passing upper trough increases will also see a boost in western upslope with MVFR cigs arriving at KLWB/KBLF and possibly KBCB late this evening and overnight. A few flurries not out of the question for KBLF/KLWB mainly after midnight. Expect downsloping flow to keep eastern locations VFR overnight once early residual low clouds clear early this evening. The drier air will erode the lower clouds Saturday morning in the mountains, with a return to VFR at all locations by midday if not sooner. Northwest winds will remain strong in the morning with gusts above 30 kts possible in the mountains and 20 kts in the east. Should finally see speeds decrease some by mid to late afternoon as the jet aloft weakens but still enough deep mixing with heating to support continued gustiness through late in the day espcly over the mountains. EXTENDED AVIATION DISCUSSION... VFR into Sunday as high pressure returns. VFR should stick around early next week, though as a weak upper disturbance passes Monday may see some MVFR ceilings in the mountains. High pressure works in from the north Tuesday and Wednesday, with VFR expected. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...Wind Advisory until 11 AM EDT Saturday for VAZ007-009>020- 022>024. NC...Wind Advisory until 11 AM EDT Saturday for NCZ001-002-018. WV...Wind Advisory until 11 AM EDT Saturday for WVZ042. && $$ SYNOPSIS...JH/WP NEAR TERM...JH/WP SHORT TERM...DS LONG TERM...DS AVIATION...AMS/JH/WP