Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/09/17

Area Forecast Discussion
National Weather Service Duluth MN
829 PM CST Wed Nov 8 2017 .UPDATE... Issued at 829 PM CST Wed Nov 8 2017 Snow continued to move south and east this evening into northern Wisconsin and was diminishing over northwest Minnesota. Reports so far from spotters range from a dusting to 2.5 inches, with the higher amounts in northern Koochiching County. The 00Z KINL sounding showed a 850mb temperature of -16C with an inversion at 5200 FT. Satellite and KBDE observation show lake effect snow occurring off of Lake of the Woods and we will keep the advisory going for for Koochiching/northern Saint Louis Counties tonight as the cold arctic air continues to move in and the fetch remains favorable off of the larger lakes in those areas. We also do not plan any updates to the South Shore advisories/warning as conditions become increasingly favorable for moderate to heavy lake effect snow tonight although fetch remains a bit too west of north for ideal conditions. But the combination of the larger scale lift with the upper trough over the region and the lake contribution should be enough for significant snowfall tonight into Thursday. && .SHORT TERM...(This evening through Thursday) Issued at 325 PM CST Wed Nov 8 2017 A wave of particularly cold, Arctic air for this time of year will move into the Northland today into Thursday. This will also be the coldest air yet seen this season. The 850 hpa will plummet to -20 degrees Celsius by Thursday morning! A passing upper trough will coincide with the timing of this cold air advection, so there will be a lot of forcing of ascent to generate widespread light snow this afternoon through tonight. Much of the Northland can expect at least 1" to 2" of snowfall. However, our large lakes in the region are relatively warm since it is still early in the cold weather season. This very cold air will move air warm lake surfaces, resulting in strong convection and quick air saturation to generate significant lake enhanced and lake effect snow downwind of these large lakes. The greatest snowfall will be downwind of Lake Superior, with the northwest flow generating about 6 to 10 inches of snow along the higher terrain of the Gogebic Range in Iron County tonight through Thursday. Other areas of northern WI, including northern Bayfield Peninsula and eastern Ashland County, can expect 3" to 6" of snowfall. Small areas of far northern MN, in northern Koochiching County and the northwest corner of St. Louis County, will get 3" to 5" of snowfall because of being downwind of Lake of the Woods, Rainy Lake, and Lake Kabetogama. Most of the snow will fall late today through Thursday morning, but there will be lingering lake effect downwind of Lake Superior through Thursday evening. In general, the snowfall was increased over the previous forecast sent early this morning. For one, the higher resolution guidance, like the latest ARW and NMM, were giving much more precipitation than the previous forecast. These two models typically overestimate precipitation for snow and lake effect snow, but do tend to do better early in the cold weather season than later in the winter because the regional large lakes are relatively warm and able to produce significant lake effect snowfall. Trended the forecast towards the latest ARW and NMM to put some stock in these models on the high side of snowfall since this cold air outbreak appears to be a rather unusual scenario, so am more comfortable placing some weighting on the high side of model guidance. Also, the RAP and GFS are suggesting there could be a 3 to 6 hour window of very favorable dendritic growth potential in northern WI tonight, which could quickly add up the snow with these high snow to liquid ratios. Another feature that lead to increasing snowfall is a potential gravity wave. The RAP suggests a gravity wave will set up over northern Bayfield Peninsula this evening, so think models may be underestimating snowfall. Increased amounts a bit over guidance to account for this potential gravity wave contribution. Snow was most increased over far northern MN since the higher resolution models were finally in play and picking up on contributions from the large inland lakes. Temperatures are expected to drop into the single digits and teens by early Thursday morning. Wind chills will be in the single digits below and above zero. Quite cold! There will be some partial clearing Thursday as drier air works into the region, so some areas will get some sunshine. Despite the sun, temperatures will only claw back into the teens. .LONG TERM...(Thursday night through Wednesday) Issued at 325 PM CST Wed Nov 8 2017 The arctic air will continue to settle into the Northland on Thursday night, before upper level ridging moves in from the west, and the deep trough moves well off to the east by 12Z Friday. Lake effect snow will be ongoing at the beginning of the night, but will gradually diminish later in the night and early on Friday. The upper level ridge will move quickly across the region on Friday, with an upper level trough and shortwave already moving into southern Saskatchewan by 00Z Saturday. Warm advection ahead of this system will bring light snow back into the region from west to east on Friday, especially in the western half of the CWA. May need to eventually bring it a bit further east Friday afternoon, but will use a compromise solution for now. The upper level trough will move into the northern border region on Friday night and Saturday, keeping the best chance of light snow in the far north. The rest of the area will see generally chance POP`s and generally light precipitation. Some rain may mix in with snow showers on Saturday afternoon, especially in the south. Our area is then expected to enter a period of dry weather, generally from Saturday night through Monday night, as upper level ridging and surface high pressure dominate during that time period. The upper level ridge will be replaced by an upper level trough from the early to middle part of the work week, with a chance of precipitation. We should once again see overnight low temperatures fall below zero in much of northern Minnesota on Thursday night. High temperatures on Friday will be in the 20s, and then warm into the 30s for the weekend and upper 30s to 40s by early next week. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 551 PM CST Wed Nov 8 2017 Cold air will continue to pour into the Northland tonight and that combined with an upper level wave will produce snow. The snow for most areas will diminish or end from north to south tonight but continue downstream of the bigger lakes in the region. MVFR/IFR conditions will be widespread this evening then gradually improve to VFR with the exception of where lake effect snow is expected. Gusty northwest winds can be expected on Thursday. && .PRELIMINARY POINT TEMPS/POPS... DLH 10 16 4 22 / 80 0 0 10 INL 6 14 -2 20 / 100 40 10 20 BRD 11 16 5 23 / 90 0 0 10 HYR 14 19 5 25 / 80 10 0 0 ASX 15 21 8 27 / 100 40 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Winter Storm Warning until midnight CST Thursday night for WIZ004. Winter Weather Advisory until 6 PM CST Thursday for WIZ002. Winter Weather Advisory until midnight CST Thursday night for WIZ003. MN...Winter Weather Advisory until 9 AM CST Thursday for MNZ010-011. LS...Small Craft Advisory from 4 AM to 10 PM CST Thursday for LSZ121- 140>148. && $$ UPDATE...Melde SHORT TERM...Grochocinski LONG TERM...DAP AVIATION...Melde
Area Forecast Discussion
National Weather Service Wilmington NC
950 PM EST Wed Nov 8 2017 .SYNOPSIS... Cool, cloudy and damp weather will persist through Thursday as waves of low pressure move along cold front to our south. Strong Canadian high pressure will bring much cooler and drier weather into the weekend. May see both, the first freeze and areas of frost, of the Fall season Saturday and possibly Sunday mornings. A mid-level impulse may bring some showers Sunday into Monday. Seasonable and dry weather will follow early next week. && .NEAR TERM /THROUGH THURSDAY/... As of 915 PM Wednesday...Will stay closer to the latest HRRR output for this update where it has intermittent light rain, drizzle and fog for majority of the evening and overnight with QPF less than one tenth of an inch. Toward daybreak Thu thru midday Thu, the ILM CWA will observe a steady light to occasionally moderate rain along with embedded heavier showers. Rainfall QPF will peak in this time frame. A mid-level s/w trof will provide the dynamics for the light to moderate overrunning stratiform pcpn. A second mid-level s/w trof tracking along the longwave upper trof, will swing to our south and east late Thu thru Thu night. This will keep the hier POPs and QPF just south and east of the FA. Used much of WPC guidance for QPF tonight thru Thu night with some modifications. Not much of a diurnal temp range this time frame, with widespread 40s for tonights lows and widespread 50s for Thu highs. Previous................................................. As of 300 PM Wednesday...Observed regional radar trends and model cross sections of column moisture indicate best rainfall potential to begin after 9z/4am. Moderately strong isentropic lift and deepening Pacific moisture will lead to a good stable rain over the region, the brunt of which falls Thursday morning but lingers into afternoon. Cold air advection via NNE flow in the lowest 3000 feet will maintain chilly conditions overnight and despite cloud cover, temperatures will fall, 46-49 inland and 49-53 ICW and coast by daybreak Thursday, and it should be raining, as the the moisture source, and the over-running are widespread in coverage. 925-700 mb moisture will see decreases Thursday afternoon, marking the onset of tapering QPF tallies, then full mid-level drying whistles in Thursday evening, as cold Canadian air spills in. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... As of 300 PM Wednesday...Expect mostly quiet conditions through the period after the residual affects of a mid level system and associated moisture move off. Surface high pressure will move from the Northern Plains to near Pennsylvania/New York by Saturday morning. Cold air advection will continue basically through the entire period. 850mb temperatures drop from near ten to about four degrees Celsius by early Saturday. Temperatures will be somewhat below normal with lows Friday in the lower to middle 40s and highs in the lower to middle 60s. Guidance is still pointing to a possible freeze Saturday morning with lower to middle 30s advertised. With the cold high centered well to the north the gradient will be supportive of some wind in the boundary layer and this may preclude a significant freeze if not a freeze entirely. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 300 PM Wednesday...A very cold day forecast Saturday, and the first frost/freeze of the season is possible, especially inland from the coast, Saturday morning. This is the short term forecast challenge, but Saturday morning will likely be the coldest so far this season, and temps will not recover much as a wedge of high pressure strengthens down the coast during the day. So, despite ample sunshine, highs will climb only into the low 50s most locations, with a stiff NE wind making it feel even colder. Beginning late Saturday, isentropic lift develops as mid-level flow backs to the SW in response to a shortwave digging across the Mtn west and the surface wedge remains entrenched. This causes increasing cloud cover and potentially some mist/drizzle Saturday night into Sunday, before the wedge erodes due to upper diffluence. However, ample cloud cover and increasing column saturation due to PVA within the approaching vort lobe/shortwave will keep temps very cool Sunday, and rain chances will increase through Sunday. The ECM remains slower and stronger with the rain into Monday, but is again not favored due to the fast flow aloft. However, will keep POP into early Monday for potential, especially as the shortwave deepens into the Mid- Atlantic and may slow at least temporarily into Monday. Do not expect abundant QPF with this event as the soundings remain relatively dry with PWATs only around one inch, but high CHC POP with low QPF will be shown attm. Cold front follows this feature into early next week bringing a return to dry and cool conditions. Temps will recover by the end of the period back towards seasonable norms, but may remain just below climo as ridging only slowly develops from the Gulf Coast. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... As of 00 UTC...High confidence for IFR/LIFR conditions through most of the forecast period. Isentropic lift will be on the increase through the overnight hours. Look for IFR ceilings/vis due to drizzle and fog. Precipitation will become more widespread after 08Z with moderate rain expected by daybreak. Winds will continue to be northerly, backing slightly on Thursday. Extended Outlook...MVFR ceilings and tempo IFR Thursday night becoming VFR Friday and continuing through Sunday. MVFR ceilings and TEMPO IFR on Monday with a frontal passage. && .MARINE... NEAR TERM /THROUGH THURSDAY/... As of 930 PM Wednesday...The SCEC remains limited to the waters from Cape Fear northward. Overall looking at NNW to NNE winds around 15 kt except 15 to 20 kt for the waters from Cape Fear northward. The sfc pg may actually tighten-some from daybreak Thu thru midday Thu, mainly across the ILM NC waters, which may end up needing to extend the SCEC well into Thu. Significant seas tonight will run 2 to 4 ft except 3 to 5 ft from Cape Fear northward. With wind directions from a northerly direction, the avbl fetch for which wind waves can build remains quite limited. A 1 to 1.5 foot Easterly ground swell at 8 to 10 second periods may be the deciding factor for the continuation of the SCEC into daylight Thu. Previous....................................................... As of 300 PM Wednesday...An "exercise caution" headline hoisted for 0-20 NM waters tonight, north of Cape Fear, for 3-5 foot seas and gusts in excess of 20 KT. If observed gusts are several kt higher than forecast, then an advisory would be needed later and could include additional marine zones southward. Dominant waves will be from the NE in 5-6 second wave periods, gradually building in height 1-1.5 feet overnight. No TSTMS expected bur rain Thursday morning could reduce visibilities to 2NM or less. SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... As of 300 PM Wednesday...High pressure will build into the waters through the period with small craft conditions almost a given for Friday through early Saturday. Strong cold air advection will commence early Friday with winds increasing from 10-15 knots from the northwest to 20-25 knots. These speeds will continue more or less through the end of the period. Seas will increase from an initial range of 2-4 feet to 5-8 feet by the end of the period. LONG TERM /SATURDAY THROUGH MONDAY/... As of 300 PM Wednesday...Wedge of high pressure aligned down the coast will keep a pinched gradient over the waters Saturday, and SCA conditions are likely. Winds from the NE will reach 20-25 kts with higher gusts much of Saturday before slowly easing into Sunday. During this period, these gusty winds will drive seas up to 5-8 ft, and the SCA will likely be needed into Saturday night. The wedge begins to weaken Sunday allowing wind speeds to fall while maintaining a N/NE direction, but will ramp back up again to 15-20 kts Monday behind a cold front. The highest seas will be confined to Sat/Sat night, but even as they fall into Sun and Mon, amplitudes will remain at least 3-4 ft if not higher at times. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...JDW NEAR TERM...DCH/MJC SHORT TERM...SHK LONG TERM...JDW AVIATION...DL
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
956 PM CST Wed Nov 8 2017 .UPDATE... Updated for evening discussion. && .DISCUSSION... Satellite imagery this evening showed a shortwave over Arkansas and a second over central Texas. Local radars had an area of light rain across the northwestern two thirds of our CWA. This area of light rain will continue shifting northeast through the night as the shortwaves swing east across our region. The back edge of the rain will taper off over our western zones after midnight, followed by decreasing clouds toward morning. The forecast handles this well and no significant changes were needed. /22/ Prior discussion below: Tonight through Thursday: Latest Rap and Satellite imagery showed flat ridging through the atmosphere. A shortwave trough was approaching the region from the Southern Plains. In the wake of the cold front a cool airmass is in place with readings 20 plus degrees cooler than on Tuesday. Isentropic lift has brought fast eastward tracking showers to the region. For the period latest CAM guidance shows that the rain will increase in coverage for this evening as the shortwave trough approaches. Could see some occasional moderate rainfall during the evening hours. The short wave is expected to pass through the region after midnight. That is when the rains will start to decrease from the west. Cam guidance shows that the rains should exit the region by Thursday afternoon. Shortwave ridging will build across the region from the west on Thursday afternoon. This will result in sunny skies across the region. As far as temperatures are concern lows tonight will range from the lower 40s northwest to the lower 50s southeast. Highs on Thursday will be a little milder with readings in the lower 60s./17/ Friday into next week: The start of this period will have upper zonal flow with northeasterly surface flow around a surface high located near the Great Lakes. The surface high will shift east over the weekend and surface flow will, in turn, shift to a southerly direction again by Saturday night. Temps will remain near normal through this time. The next shortwave is progged to come off of the Pacific onto the Northwest U.S. coast on Friday, track through the northern Rockies, and then southeast through the Plains over the weekend. By Sunday, the shortwave will have developed into a weak cutoff low over the mid- Mississippi Valley. The trough will bring a weak cold front through our CWA late Sunday along with some weak rain chances. The models continue their downward trend in intensity with this system. Behind the front, a reinforcing cool airmass will filter into the area and essentially maintain the seasonal temps going into early next week. /10/ && .AVIATION... 00Z TAF discussion: Widespread MVFR cigs were being observed at 00Z with -RA increasing in coverage from the west. Conditions will lower to IFR as a disturbance moves across the region overnight. Conds wl begin improve to VFR from the west after 08Z. VFR conds are expected areawide after 18Z Thu and wl prevail through Thu night. /22/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 48 61 43 66 / 81 12 0 1 Meridian 49 62 41 66 / 80 18 0 1 Vicksburg 47 62 41 66 / 84 6 1 1 Hattiesburg 52 64 43 68 / 62 27 1 1 Natchez 48 61 43 66 / 71 8 1 1 Greenville 43 60 41 63 / 85 3 0 1 Greenwood 43 62 40 64 / 85 7 0 1 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ 10/17/22
National Weather Service Jackson KY
1025 PM EST Wed Nov 8 2017 .UPDATE... Issued at 1025 PM EST WED NOV 8 2017 Did a quick update to the grids mainly to fine tune the PoPs through the night per the latest HRRR and NAM12 guidance with some sprinkles falling in the far southern parts of the CWA ATTM. Also, added in the latest obs and trends for the T/Td. These have been sent to the NDFD and web servers. An updated set of zones will follow shortly. UPDATE Issued at 645 PM EST WED NOV 8 2017 23z sfc analysis shows an inverted trough through the southern Appalachians brushing up against southeast Kentucky. High pressure to the northwest is bringing in cooler and drier air on northerly winds. Skies are cloudy for the bulk of the area with some sprinkles possible right along the Tennessee and Virginia border from the lower clouds. Temperatures are running in the low to mid 40s most places with dewpoints in the upper 30s to lower 40s. The latest HRRR and 18z NAM12 suggest that light rain or sprinkles will be possible in the far south later tonight into Thursday morning. Have nudged the forecast in that direction with this update. Also, added in the latest obs and trends to the T/Td grids. These have been sent to the NDFD and web servers. && .SHORT TERM...(This evening through Thursday night) Issued at 326 PM EST WED NOV 8 2017 Current conditions across the area feature some lingering low level moisture slow to exit the area as the weakening front sags south of the TN border and east of the VA border. This is due to an anchored area of high pressure as the southern axis extend south along the lee side of the Appalachian Range. In fact, the slow exit of the cloud cover will lead to slowly falling temps across much of the area. However, some clearing may creep into the Bluegrass with low temps tonight plummeting into the low 30s. By the late morning into Thursday afternoon, a push from the northwest will clear out the area with high temps warming into the mid 50s across eastern Kentucky. High pressure will then begin to settle into the area with the colder part of the incoming air mass beginning to settle into the area. This will typical behavior of the sheltered valleys of eastern Kentucky will cause some of the valleys in the east Thursday night to plummet into the mid and upper 20s. Overall, the short term looks dry and colder then normal values. .LONG TERM...(Friday through Wednesday) Issued at 355 PM EST WED NOV 8 2017 The models are in generally good agreement with a progressive long wave pattern to rule across the CONUS through the period. Smaller scale features remain in question late this weekend and next week, due to varying timing and amplitude differences. For eastern Kentucky, high pressure will remain in control through the first half of the weekend. Temperatures will be well below normal, with highs on Friday struggling to reach the 40 degree mark. Lows Friday night will dip down into the mid to upper 20s, with the northeastern valleys possibly seeing lower 20s. Return flow will engage on Saturday, with highs returning to the 50s, closer to normal for this time of year. A cold front will approach and eventually move through Sunday through Monday, bringing a good chance of rain showers to the area, especially from Sunday afternoon through Sunday night. The latest 12z GFS is more progressive and less intense with the surface and upper level features, while the latest 12z ECMWF remains slower, and has trended a bit more amplified compared to the 00z run. Have favored a solution closer to the ECMWF, given its better verification. Temperatures will not modify much behind this system, with highs remaining in the 50s next week. Another short wave will approach the area on Wednesday, justifying at least chance POPs, but not likely at this point, given the model differences in strength of this feature. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) ISSUED AT 655 PM EST WED NOV 8 2017 Aviation impacts tonight will be focused on lingering low level moisture slowly exiting the area to the southeast. Thus will expect some IFR and below cigs tonight, especially in the south and east. With this, we will also see a potential for showers and sprinkles, but likely too far south of any TAF site. Conditions will improve from northwest to southeast into Thursday morning with the entire area likely to be VFR by 12z. Winds will be light through the period with direction mainly being from the north. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...SHALLENBERGER LONG TERM...GEOGERIAN AVIATION...GREIF
Area Forecast Discussion
National Weather Service Melbourne FL
847 PM EST Wed Nov 8 2017 .UPDATE... Tonight...The fog forecast is challenging again tonight. Diminishing high pressure over the area will lead to light low level winds but skies won`t be crystal clear like previous nights. Considerable thin cirrus will advance across the area ahead of a frontal boundary in north Florida. Onshore low level flow across the south half will probably produce some stratocumulus too. Overall, the surface has been drying out with no rainfall in some spots this month. Also lower dew points mixed down again over the interior during the afternoon. These mixed signals have the models showing a wide range of solutions. The HRRR model and local WRF only have patchy fog. Other high resolution models, taking their cue from the NAM, indicate areas of fog in the south. The 18z MOS guidance actually showed brief LIFR across the north interior. Like last night, not confident that it will be a big fog night areawide, but will hold onto a mention of areas of fog over the interior and patchy fog in the coastal counties. Patchy dense fog is also discussed in the Hazardous Weather Outlook. && .AVIATION... VFR prevailing through late evening then there is a chance for fog again, which will be locally dense. A few terminals could be affected by IFR-LIFR, especially ISM-MCO-SFB-LEE, but mixed signals from the models does not lend enough confidence to include that in the TAFs just yet. The fog will again dissipate a little after sunrise. && .MARINE... (Previous Discussion) Tonight-Thursday...Benign wind/sea conditions expected. Thu will be the last favorable boating day before the front moves into the region Thu night. Winds will be relatively light and variable around 5 to 10 knots, with seas 2-3 feet. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Lascody/Sedlock
Area Forecast Discussion
National Weather Service Marquette MI
646 PM EST Wed Nov 8 2017 .SHORT TERM...(This evening through Thursday) Issued at 407 PM EST WED NOV 8 2017 Water vapor imagery and RAP analysis show a deep trof over central Canada. Pair of shortwaves swinging around the trof will affect the Upper Great Lakes during the short term. The first extends from northern Ontario to southern Saskatchewan with the second dropping into far northern Saskatchewan. Ahead of the first wave, sfc trof extending w to e across Lake Superior, including the Keweenaw has sharpened up a bit this aftn. Despite 850mb temps around -10C, there has been little -shsn activity in the vcnty of the trof, likely due to the dry air noted on the 12z KINL sounding. Upstream, radars show an area of -sn associated with shortwave moving across ND/northern MN. As stronger deep layer forcing associated with first shortwave arrives this evening, expect a rapid increase in lake enhanced snow showers over Lake Superior. With the sfc trof already cutting across the Keweenaw, heavier lake enhanced snow will likely end up developing to the s of the Keweenaw this evening. Across the rest of the northern U.P., expect a period of mdt/hvy snow to accompany the sfc trof as it pushes s thru the night. The trof should have moved onshore across all of the western fcst area by 08z and should move onshore from Marquette eastward in the 08-10z time frame. Will likely see at least 1-2in/hr snowfall rates with this band as fcst soundings show the typical result of shortwave/cold fropa during the cold season, including loss of inversion, deep moisture, strong low- level convergence. While models show a fairly sharp wind shift associated with cold fropa tonight, there probably would have been sharper convergence and a more impressive period of lake enhanced snow if the stronger second shortwave was not proceeded by the weaker wave tonight. Away from the lake enhanced snowfall, expect all areas to see at least some -sn tonight as upstream area of forcing and -sn spread across the area. After the sfc trof passes, NW flow oriented LES will then organize thru Thu morning. Strong large scale subsidence/drier air arriving Thu will be a big negative for hvy LES during Thu, especially over the w due to the strong subsidence arriving early in the day and due to shorter overwater fetch. While this will be offset a little by the DGZ being well positioned in the convective layer to boost snow-to-water ratios, overall snow accumulations will be held down as the wind parallel LES bands will likely develop fair separation due to the subsidence/dry air. In addition to the longer fetch into the ne fcst area, that part of the area will also be brushed during the morning by deep layer forcing for upward motion associated with the second stronger shortwave. So, heaviest snowfall on Thu will occur east of Marquette, especially where bands tied to Lake Nipigon preconditioning stream onshore, probably in eastern Alger/Luce counties. Overall for most locations, this fcst reflects lower snow accumulations for the 00z Thu to 24z Thu timeframe given the strong subsidence/dry air arriving on Thu. At the high end, there should be a few totals around 10in in the high terrain btwn Ironwood and Painesdale and 10-12in in Alger/Luce counties. Winds will also be gusty on Thu, upwards of 30 to 40 mph along Lake Superior. This will lead to some areas of blsn. With steady CAA thru the day, temps on Thu will change little from lows tonight. Much of the nw half should see temps in the teens thru the day. .LONG TERM...(Thursday night through Wednesday) Issued at 338 PM EST WED NOV 8 2017 Focus is on diminishing LES Thu night into Fri then snowfall with an incoming system Fri night into Sat night. Ongoing LES will diminish Thu night into Fri, fastest over the W, and lingering longest over N-central Upper MI into Fri afternoon (although the lingering precip on Fri will be light). Have just 1-2" new snow during this time in the snowbelts of the W half, while over the E half have 3-8" new snow, greatest over central and western Alger County. Still disagreement on the strength of an incoming shortwave, which will enhance WAA forced precip across the CWA. The greatest uncertainty exists in how much precip (mainly or all falling as snow) will occur over the central and western U.P. and how much enhancement will occur off Lake Michigan with the southerly winds. Current 24hr forecast snowfall totals show no snow near Ironwood, 1- 2" over the rest of the W, 1-3" over the central and far E, and 4-7" N of Lake Michigan over portions of Delta, Alger and Schoolcraft Counties. Again, potential exists for lower or higher amounts. Ratios will be around 12:1, so could see advisory level impacts given current forecast. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 645 PM EST WED NOV 8 2017 An approaching disturbance and a passing cold front will lead to increasing lake enhanced snow showers from nw to se tonight. MVFR conditions at KIWD/KCMX will fall to LIFR as the heavier snow showers develop this evening. At KSAW, VFR cigs will prevail this evening, before shsn develop overnight and drop conditions to IFR. During Thu morning, prevailing IFR conditions should be the rule at KIWD/KCMX under shsn/blsn, but as is typical for lake effect, conditions will be variable with LIFR and MVFR possible at times. At KSAW, conditions will improve to MVFR as heavier lake effect shsn bands shift e of the terminal. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 421 PM EST WED NOV 8 2017 Cold front will drop s of Lake Superior tonight, followed by a surge of very cold air for this time of year. This will result in nw winds reaching gale force across central and eastern Lake Superior Thu into Thu evening. Freezing spray will also develop Thu, continuing Thu night. Winds will diminish w to e Thu night/Fri, falling blo 15kt for a time as sfc high pres moves across Lake Superior. Winds will then quickly ramp back up to 20 to 30 knots for Fri night/Sat as the high departs and a low pres trof approaches. After the trof passes, winds will fall back to mostly under 20kt for Sun/Mon. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Winter Weather Advisory until 7 PM EST Thursday for MIZ004-084. Winter Storm Warning from 10 PM this evening to 7 AM EST Friday for MIZ006-007-085. Winter Storm Warning until 7 AM EST Friday for MIZ001-003. Winter Storm Warning until 1 AM EST /midnight CST/ Friday for MIZ002-009. Winter Weather Advisory from 10 PM this evening to 7 AM EST Friday for MIZ005. Winter Weather Advisory from 1 AM Thursday to 1 AM EST Friday for MIZ013-014. Lake Superior... Gale Warning from 7 AM Thursday to midnight EST Thursday night for LSZ244>251-264>267. Lake Michigan... Gale Warning from 7 AM to 10 PM EST Thursday for LMZ221-248-250. && $$ SHORT TERM...Rolfson LONG TERM...Titus AVIATION...JLB MARINE...Rolfson
Area Forecast Discussion
National Weather Service San Francisco Bay Area
419 PM PST Wed Nov 8 2017 .SYNOPSIS...Rain will increase in coverage and intensity from north to south across the region late this afternoon and through the overnight as a cold front pushes inland. Southerly winds will also increase and become gusty at times, especially in the hills/mountains tonight. Lingering showers are possible Thursday into early Friday, mainly over the northern portion of the region. Drying is likely Friday afternoon through the upcoming weekend before another round of light rainfall arrives Sunday night into Monday. && of 01:46 PM PST Wednesday...Deeper moisture is advecting into the region ahead of a Pacific frontal boundary early this afternoon with light rainfall reaching the ground in portions of Sonoma County. As the front continues to approach the region and southerly winds increase, look for rainfall to increase along the coastal ranges and more widespread rainfall to develop across the North Bay later this afternoon and evening. The latest HRRR is showing rain rates increasing to around a few hundredths of an inch per hour in valley locations and upwards of 0.10" to 0.25" per hour in the coastal ranges and higher elevations as the frontal boundary shifts from north to south through the night. As mentioned above, the winds will continue to increase out of the south ahead of the main frontal boundary with breezy conditions developing. Locally strong and gusty winds are possible in the highest elevations and along the coastal ridges this afternoon and evening. Rainfall as well as wind speeds will then diminish and tapper off from north to south Thursday morning with lingering rain showers possible into midmorning. By Thursday afternoon, dry conditions are likely to develop over the Central Coast as another weak short-wave disturbance pushes inland to our north. This will allow for another round of light precipitation over the northern half of the region from late in the day Thursday into early Friday morning. However, not expecting much additional rainfall from this system south of the Santa Cruz Mountains. When all said and done, rainfall totals are expected to range from 0.50"-0.75" (locally upwards of 1.00") in the North Bay Valleys to 0.75"-2.00" in the North Bay Mountains/Hills and Santa Cruz Mountains with lesser amounts for the Santa Lucia Mountains and especially so for inland ranges. Expecting 0.25"-0.50" around San Francisco and the Bayfront while 0.15" or less is likely from the South Bay southward to the Monterey region. By Friday afternoon, region-wide drying is likely and will continue through the majority of the upcoming weekend. Given a lack of cold air advection in wake of these frontal passages, temperatures will not change much through the upcoming week and continue to be near seasonal averages. Another round of rain is then expected to return late Sunday into Monday morning as another weak frontal boundary pushes through the region. At this time, looking for this system to produce much lighter rainfall amounts region-wide with potentially little to no precipitation south of the Santa Cruz Mountains. Will continue to monitor this next system in the coming days and made needed adjustments to the forecast. && .AVIATION...As of 4:19 PM PST Wednesday...00z tafs go with lowering cigs and visibilities due to cold frontal rain band moving in from the northwest. Moderate rain now reported at KUKI. Gusty southerly wind flow aloft has spread over much of the Bay Area, while the best vertical wind mixing has been at the coast and over the coastal waters e.g. Bodega Bay profiler reports SE wind to 35 knots down to 700 feet. One remote weather observing location in the North Bay Mountains reported wind gusts near 40 knots earlier this afternoon while surface winds over land are lighter; 12z WRF shows pockets of southerly wind gusts topping 50 knots at 925 mb tonight. Lighter, warmer air with warm sector is mostly riding up and over residual near surface stable layer over the Bay Area increasing chances there`ll be low level wind shear going into this evening. Rain, and wind both surface and aloft gradually dissipate early Thursday morning. Vicinity of KSFO...MVFR cigs with rain developing this evening, occasionally gusty SE winds. Low level wind shear probable 04z-12z as stronger 925 mb and 850 mb flow reaches the SF Peninsula. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...VFR/MVFR with light rain arriving later this evening. Occasionally gusty SE winds possible later tonight. && of 3:43 PM PST Wednesday...Gusty winds will continue through early Thursday as a storm system sweeps through the region. The passing storm will also bring fresh swell and steep wind waves. Conditions will improve Thursday evening into Friday. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Pt Reyes to Pigeon Pt 0-10 nm SCA...Pigeon Pt to Pt Pinos 0-10 nm SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm SCA...Pt Arena to Pt Reyes 0-10 nm until 3 AM SCA...Pt Arena to Pigeon Pt 10-60 nm until 3 AM SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 3 AM SCA...Mry Bay from 9 PM until 3 AM SCA...SF Bay && $$ PUBLIC FORECAST: RGass AVIATION: Canepa MARINE: MM Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Pueblo CO
638 PM MST Wed Nov 8 2017 .UPDATE... Issued at 630 PM MST Wed Nov 8 2017 Updated forecast to add more fog along the I-25 corridor across El Paso and Pueblo counties where it has been locally dense at times. Generally followed the HRRR which suggests fog should continue and possibly shift southward out of the COS area late this evening as northerly drainage winds off the Palmer Divide take hold. For now dense fog seems too localized for an advisory, but will monitor trends and may have to issue a dense fog advisory if conditions expand sufficiently in coverage. -KT && .SHORT TERM...(This evening through Thursday) Issued at 346 PM MST Wed Nov 8 2017 Currently... Low clouds and some fog were still hanging tough over the lower elevations of southern El Paso county and northern Pueblo county. Otherwise...skies were clearly over the cwa. Temps over the area at 2 pm were generally in the 40s over the plains, except in the 30s where clouds were still present. The valleys were also in the 40s and the mtns were in the 20s and 30s. Tonight... Only concern for tonight is will there be more fog redeveloping over parts of the plains? I believe El Paso will not see any fog as all guidance shows downslope surface winds developing and that should bring drier air to this region. The area of highest concern will be along the river in Pueblo county and possibly a bit farther east as the remnant melting snow will add low level humidity for potential fog formation. Otherwise, should see clear skies across region. A weak cool front will move down across the far eastern plains late tonight. Thursday... The cool front will bring another shot of slightly cooler air to the the far eastern plains, and max temperatures this region will only reach into the 45-50F range. Farther west along the I-25 corridor it will be a bit warmer than today with reading in the mid 40s to mid 50s. The warmest temps tomorrow may actually be in the san luis valleys were highs around 60s will be possible. Skies will generally be mostly clear tomorrow and winds will relatively light. .LONG TERM...(Thursday night through next Wednesday) Issued at 346 PM MST Wed Nov 8 2017 Relatively benign meteorological conditions are anticipated over the forecast district during the longer term with primary concerns being temperatures and gusty winds at times. Recent computer simulations, forecast model soundings and PV/Precipitable Water analysis indicate that a basically dry and mild to warm meteorological pattern should be noted over the forecast district during the balance of the longer term as dry zonal to southwesterly upper flow in combination with varying degrees of eastern Colorado lee-side surface troughing(outside of dry northerly/northeasterly surface surges Saturday night and Tuesday evening) impact the CWA. The highest potential for gusty winds during the longer term are expected from Monday evening into Tuesday and then again by later Wednesday. Warmest temperatures during the longer term over the forecast district should be realized Monday and Tuesday, while coolest temperatures are projected Thursday night and Sunday(although maximum and minimum temperatures are expected to generally remain above early to mid-November climatological averages). && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 346 PM MST Wed Nov 8 2017 COS... Skies should clear out by late this afternoon or early evening. With downslope sfc flow developing it should dry out and we should see VFR conditions at KCOS this evening lasting into tomorrow afternoon. KPUB... With quite a bit of llvl moisture over the region and light winds, concerned that KPUB may see low cigs continue with the chance of fog over the tat site this evening into tomorrow morning. However skies should clear out by mid morning with VFR conditions thereafter. KALS... VFR next 24 hours. However, some hi res guidance does show the possibility of some ground fog tomorrow morning. Will allow later shifts to monitor and adjust TAF fcst accordingly. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KT