Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/12/19

Area Forecast Discussion
National Weather Service Grand Rapids MI
939 PM EST Mon Nov 11 2019 LATEST UPDATE... Update .SYNOPSIS... Issued at 330 PM EST Mon Nov 11 2019 -Widespread snow south and east of Grand Rapids ending from northwest to southeast this afternoon and early evening. -Localized but intense lake effect snow impacting the Lake Michigan shoreline tonight into Tuesday around South Haven and Ludington -Over one foot of new snow possible between Holland and Benton Harbor, including I-196 and where I-94 meets I-196 -Additional light snow Wednesday afternoon and night; then dry through next weekend -Record or near record cold through Wednesday, moderating above freezing for the end of the week. && .UPDATE... Issued at 929 PM EST Mon Nov 11 2019 I decided to add Lake...Muskegon and Ottawa Counties to the Winter Weather Advisory. Bands of lake effect snow were on the increase across these counties. New guidance indicates that some of these bands will become locally intense and capable of several inches of snow in several hours. This risk continues right through the morning commute and possibly the afternoon. Thus with multiple highways/routes through these regions impacted travel looks likely. We will need to monitor Kalamazoo County as western parts of the county are at an increase risk for impacts. Not all guidance bring the heavier bands into the county. I did add to the hazardous weather outlook a risk for impacts from the system that moves in Wednesday afternoon into the night. This looks like a south to southwest flow event with lake moisture enhancing the fast moving system which moves in. Guidance has been increasing the snowfall with this one...along with the winds to it is looking increasingly likely that we may see some impacts. Right now the area from Muskegon north to Ludington is forecasted to see the most snow and wind. && .DISCUSSION...(This evening through next Monday) Issued at 330 PM EST Mon Nov 11 2019 Will probably remove a few counties from the Winter Wx Advisory on the northwest edge of the departing area of snow with this update. Otherwise the current expiration of 7 PM looks good and JXN will be the last to see the snow end around that time. Have had several reports around 6 inches, and locations some could reach 8-9" around JXN. Yet another right entrance region jet/mid level FGEN event that over-performed. Based on the hi res guidance/HREF probability matched mean QPF showing over one inch of water equivalent from the lake effect snow band that hits far SW Lwr MI tonight, have decided to bump Van Buren and Allegan counties into a warning alongside the counties which the IWX office already has in a warning. Fcst soundings from the HRRR and NAM 3km at South Haven have deep inversion heights to 10,000 ft or more and the lift in the DGZ is about as impressive as it gets. Strong potential for snow rates of 2 inches or more per hour and whiteouts tonight into early Tuesday could lead to some serious travel impacts along I-196 south of Holland and I-94 west of Kalamazoo. Temperatures falling to around 20 in this area should result in slick roads and with the extreme snowfall rates we could end up with multi-car pileups and lengthy traffic stoppages in that heavily traveled area of SW Lwr MI. The event should be peaking during the Tuesday morning commute. Meanwhile the intense N-S oriented band currently stretching down the length of the entire lake still remains just offshore of Ludington but will be moving onshore soon. Winds have become NNW and Frankfort currently has a 1/4 mile vsby. Hi res guidance not showing quite as much qpf in this area as south of Holland tonight and Tues, but still would not rule out some localized amounts near one foot, especially with guidance suggesting the possibility of a meso-low sliding south down the shoreline early Tuesday. Will keep Mason and Oceana counties in an Advisory but have extended it through 5 PM Tuesday (warning south of Holland will go through 5 PM as well). Weakening trend in the lake effect develops later Tuesday and especially on Tuesday night as the sfc ridge arrives. Another burst of snow, with sw flow lake enhancement, arrives Wednesday afternoon. Accums with this probably an inch or less south and east of GRR but potential for 2-4" along the coast north of Grand Haven. Much quieter weather and milder temps expected for Thursday and beyond. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 625 PM EST Mon Nov 11 2019 The main area of snow that led to impacts across the area was pulling east of KJXN. However one more band was try to develop between KLAN and KGRR. This should pull east over the next couple of hours and could lead to a temporary reduction in the ceilings and visibilities for some of the sites this evening. Lake effect snow bands will be moving onshore through the night and into Wednesday. It looks likely that impacts will occur generally along and west of a KGRR to KBTL line. Initially the impacts will be seen at KMKG...then further inland into Tuesday as the winds shift slightly. IFR looks likely with brief reductions to LIFR a possibility especially closer to the lakeshore. && .MARINE... Issued at 330 PM EST Mon Nov 11 2019 No changes to the going marine headlines. Small craft advisories in effect through Tuesday night for the strong northerly flow which becomes northwest for Tuesday. Freezing spray may develop tonight as the colder Arctic air pours in. Lakeshore Flood Advisory continues for Allegan and Van Buren Counties Beach and bluff erosion is expected, as well as lakeshore flooding in low lying areas and along river mouths. && .CLIMATE... Issued at 330 PM EST Mon Nov 11 2019 The current forecast of high temperatures in the mid 20s on Tuesday would break the daily record for coldest highs (or lowest maximum temperature). The low temperature forecast for Tuesday and Wednesday would come within a few degrees of breaking daily records at some locations. Record coldest high temperatures for November 12: Grand Rapids... 27 (1920) Muskegon....... 27 (1940) Lansing........ 29 (1995) Kalamazoo...... 28 (1920) Record Low Temperatures for November 13: Grand Rapids... 10 (1986) Muskegon....... 11 (1911) Lansing..........1 (1872) Kalamazoo...... 12 (1986) && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Storm Warning until 5 PM EST Tuesday for MIZ064-071. Lakeshore Flood Advisory until 5 PM EST Tuesday for MIZ064-071. Winter Weather Advisory until 5 PM EST Tuesday for MIZ037-038- 043-050-056. LM...Small Craft Advisory until 11 PM EST Tuesday for LMZ844>849. && $$ UPDATE...MJS SYNOPSIS...Meade DISCUSSION...Meade AVIATION...MJS CLIMATE...Meade MARINE...Meade
Area Forecast Discussion
National Weather Service Houston/Galveston TX
800 PM CST Mon Nov 11 2019 .AVIATION... Cold front is off the coast and winds have increased significantly. A mix of IFR/MVFR ceilings will transition to MVFR overnight and to VFR ceilings by mid morning Tuesday. Skies will clear Tuesday afternoon and winds will gradually diminish. As for precip tonight, fcst soundings would suggest patchy light rain and drizzle this evening with some potential for some sleet to mix with the rain before the 850 front pushes remaining precip toward the coast. 43 && .PREV DISCUSSION... /ISSUED 633 PM CST Mon Nov 11 2019/ UPDATE... Surface cold front will continue to move southward into the local waters this evening. Winds are increasing and temperatures are decreasing quickly in the wake of the front. Surface observations are currently reporting temperatures in the low to mid 40s at College Station, Huntsville and Conroe. Additionally, a band of light rain is currently moving over Burleson, Brazos, Madison, northern Grimes, and Walker counties. Law enforcement has reported a mix of light sleet and rain in Wixon Valley at around 540 PM CST today. The probability of light sleet will continue tonight as rainfall continues and temperatures decrease even further in these regions. Slight adjustments were made to account for the current temperature trend as well as the reported surface observations. The POPs across the northern counties was increased to account for the current rainfall and temperatures were slightly adjusted (lowered). Moreover, the chance of light sleet was included for the Washington, Burleson, Brazos, Grimes, Madison, northern Montgomery, northern San Jacinto, Houston, Walker, Trinity and northern Polk counties through tonight. 24/43 PREV DISCUSSION... /ISSUED 343 PM CST Mon Nov 11 2019/ SHORT TERM [Tonight through Tuesday]... Cold front continues to crash south as a typical Texas blue norther` with temperatures falling into the 40s rather quickly behind the front and winds gusting around 35 knots. Frontal timing looks on track with basic HRRR model trends and continue to use it as our first guess for winds/temps/dewpoints etc since it seems to be handling the situation the best. By midnight we are looking at temperatures in the mid/upper 30s for the northern half of the area and 40s along the coast. Winds will be quite strong overnight so wind chill values could be in the upper teens for areas north of Brenham to Huntsville and 20s for the rest of SE Texas. Wind advisory has been extended to all areas and pushed up in time as winds behind the front gusted to 30-35 knots and then settle down to lower values. Strong cold air advection and tight pressure gradient will support strong winds all night so will keep wind advisory going until 6AM Tuesday. Any time we get a strong surge of cold Canadian air, the question of frozen precip arises. Looking aloft there is a jet streak and trough axis that are pushing SE through the Plains. By 06Z Tue (midnight) this feature moves into N Texas with the right entrance area over central and eastern Texas. This places a fair amount of the area under large scale ascent along with frontogenesis in the 925-850mb and 850-700mb layers. Model soundings support the threat for frozen precip at the boundary layer cools but will it be cold enough in time? There looks to be a window from 05Z to 11Z that there is a thick enough sub-freezing layer that we could see a mix of rain/sleet and perhaps freezing rain if SFC temperatures are cold enough. With grounds warm by temperatures in the 70s today, there should not be any accumulations if we do get frozen precip. The next question in the forecast will be how quickly drier air in the 850- 700mb layer moves into the region with the 850mb front after 06Z? Model soundings suggest this will be a problem and could end precipitation production. This certainly looks to be the case around 12Z Tuesday when temperatures are the lowest. Forecasting marginal winter weather events is the norm around here so we are looking at mentioning a mix of rain/sleet/freezing rain in the forecast. Which areas? Mainly west of I-45 and north of I-10 not including Houston. Basically an area from College Station to Huntsville to Conroe to Katy to Columbus from 06Z to 11Z Tuesday. So there`s a chance, but several conditions have to come together for it to happen. In the end we are not expecting accumulations and little impacts. Overpeck LONG TERM [Tuesday Night through Monday]... Very cold temperatures on tap for Tues night/Weds morning as the sur- face high settles over the state. A Hard Freeze Warning is likely for the northern portions of the FA, with a Freeze Warning (for the first freeze of the season) expected across the central/southern counties. Record low temperatures are a good possibility. Warming temperatures are forecast for Wed as very light onshore winds return in response to the surface high shifting east. Rain chances do look to return by Weds night/Thur as a fairly well-defined upper trof (closed low combo) moves in from the west. Models have waffled a lit- tle with how much moisture will be available with the passage of this system, but given its projected path across SE TX and how deep/strong it is progged to be, scattered showers (and maybe some isolated thun- derstorms) will be possible. A secondary shot of cold/dry air will be moving into the region behind this system for the rest of the week. Extended guidance indicating the upper ridge that was to build in ac- ross the region (in the wake of the midweek system) could be somewhat flatter than previously thought. The upper pattern appears to be get- ting a little more progressive as a series of of deep long-wave trofs move across from the west. 41 MARINE... A strong cold front is continuing to push across the region this afternoon and should be reaching our western nearshore waters around 6 PM this evening and only slightly later across our eastern waters. Gale Warnings are in effect for all local waters starting at 6 PM this evening and will continue through at least early Tuesday morning before transitioning to Small Craft Advisories (SCA) across both bays. Gale Warnings should continue across the rest of the Gulf waters through at least the late afternoon hours tomorrow before eventually also transitioning to a SCA. In addition, Low Water Advisories are in effect for both Matagorda and Galveston Bay starting this evening at 9 PM to allow for the winds to push the water out of the bays. The Low Water Advisories will continue until we transition out of the low tide cycle, so at least through tomorrow afternoon. Tide levels should reach a foot below MLLW across Galveston Bay and a half to a foot below MLLW across Matagorda Bay. Winds should turn back out of the east on Wednesday and eventually onshore for a short time Thursday morning. A second front looks to push through the region late Thursday into Friday. Winds should stay offshore through the early part of the weekend. Hathaway CLIMATE... Record lowest maximum temperatures tomorrow (11/12) and lowest minimum temperatures tomorrow night (11/13) could potentially be broken, behind the strong cold front that is pushing through the region today. We will need to keep a close eye on temperatures over the next 24-36 hours to see if we will set any new records! Here is the breakdown of what we are forecasting (fcst) versus what the records are... Fcst High Record High Low Fcst Low Record Low Temp 11/12 Max Temp Temp 11/13 Min Temp CLL 44 44-1907 24 25-1911 IAH 45 44-1907 29 29-1907 HOU 46 50-1939 31 30-1932 GLS 48 43-1907 28 35-1911 Hathaway && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 28 44 24 53 39 / 60 10 0 0 20 Houston (IAH) 34 45 29 51 39 / 50 10 0 0 30 Galveston (GLS) 41 48 38 54 49 / 80 30 0 10 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Wind Advisory until 2 PM CST Tuesday for the following zones: Brazoria Islands...Coastal Brazoria...Coastal Galveston... Coastal Jackson...Coastal Matagorda...Galveston Island and Bolivar Peninsula...Matagorda Islands. Wind Advisory until 6 AM CST Tuesday for the following zones: Austin...Brazos...Burleson...Chambers...Coastal Harris... Colorado...Fort Bend...Grimes...Houston...Inland Brazoria... Inland Galveston...Inland Harris...Inland Jackson...Inland Matagorda...Madison...Montgomery...Northern Liberty... Polk...San Jacinto...Southern Liberty...Trinity...Walker... Waller...Washington...Wharton. GM...Small Craft Advisory from 10 AM Tuesday to midnight CST Tuesday night for the following zones: Galveston Bay...Matagorda Bay. Gale Warning until 10 AM CST Tuesday for the following zones: Galveston Bay...Matagorda Bay. Small Craft Advisory from 5 PM Tuesday to midnight CST Tuesday night for the following zones: Coastal waters from Freeport to Matagorda Ship Channel TX out 20 NM...Coastal waters from High Island to Freeport TX out 20 NM...Waters from Freeport to Matagorda Ship Channel TX from 20 to 60 NM... Waters from High Island to Freeport TX from 20 to 60 NM. Gale Warning until 5 PM CST Tuesday for the following zones: Coastal waters from Freeport to Matagorda Ship Channel TX out 20 NM...Coastal waters from High Island to Freeport TX out 20 NM...Waters from Freeport to Matagorda Ship Channel TX from 20 to 60 NM...Waters from High Island to Freeport TX from 20 to 60 NM. && $$ Discussion...43 Aviation/Marine...43
Area Forecast Discussion
National Weather Service North Platte NE
1004 PM CST Mon Nov 11 2019 .UPDATE... Issued at 959 PM CST Mon Nov 11 2019 Updated for slightly colder temperatures tonight. Many locations have already seen temperatures reach the low single digits above and below zero. As south to southwest winds increase after midnight, temperatures will slowly rise in some locations. Also raised highs Tuesday to the mid 50s far southwest, and lower 50s near and west of Highway 83. Highs around 40 in the northeast. Southwest winds will increase to 10 to 20 mph with gusts to 25 mph late morning into the afternoon to aid in the warmup. && .SHORT TERM...(This evening through Tuesday night) Issued at 314 PM CST Mon Nov 11 2019 Arctic high pressure will move south of Nebraska tonight leading to lowest temperatures before or around midnight. Thereafter, south winds will cause steady or slowly rising temperatures. There is a good chance that evening lows will fall below zero but it is difficult to predict because temperatures at the h850mb level will be rising across western Nebraska. The temperature guidance, including the RAP and HRRR models do not support subzero lows. Only the Canadian model shows what could happen and given the snow cover, it is the basis for the temperature forecast tonight. Subzero lows to 5 below zero are most likely across ncntl Nebraska where winds will be light for many hours. Wind chill readings of 5 below to 15 below zero are likely in this area. The temperature forecast Tuesday uses the cooler deterministic model blend forecast for highs in the 30s, 40s and near 50. This is several degrees cooler than the blended guidance and several more degrees cooler than the bias corrected guidance blend. An upper level disturbance, currently near the coast of British Columbia, will move into nrn Nebraska Tuesday night and spread a period of light snow and sleet. The NAMnest is the basis for the forecast which uses the short term model blend. Predicted snowfall of a dusting is in place Tuesday night and the ptype includes sleet as temperatures aloft will be 1-2C above zero Celsius. .LONG TERM...(Wednesday through Monday) Issued at 314 PM CST Mon Nov 11 2019 The upper level disturbance moving in Tuesday night exits ncntl Nebraska Wednesday morning followed by a weak cold front. Below average temperatures in the 40s and lower 50s are in place Wednesday. Thereafter, temperatures aloft at h850mb warm to around 10C supporting highs mostly in the 50s. A weak cold front moves through Sunday. Mild weather resumes Monday. The forecast is dry Thursday and Friday with just isolated showers possible Saturday and Sunday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 623 PM CST Mon Nov 11 2019 Clear skies and VFR conditions will prevail right through the day Tuesday across western and north central Nebraska. Winds will shift to the south and increase 15 to 25 kt by noontime Tuesday. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Roberg SHORT TERM...CDC LONG TERM...CDC AVIATION...Taylor
Updated for 00Z Aviation Forecast Discussion below.

&& .PREV DISCUSSION... /issued 338 PM CST Mon Nov 11 2019/ DISCUSSION... A strong cold front is barreling through the Mid-South this afternoon and is located roughly along the Interstate 40 corridor as of 3 PM. Temperatures behind the front are quickly dropping into the mid 40s and will continue to fall through the evening as cold air rushes into the region from the north. Temperatures in southern MO are already around freezing with snow observed as near as Poplar Bluff, MO. The rain/snow line will shift south throughout the evening, but will be racing against the dry air aloft approaching from the northwest along the trough axis. Strong frontogenetic forcing will exist in behind the cold front, gradually diminishing and lifting into the mid-levels through early Tuesday. This will maintain precipitation well into the evening hours. Rain will generally change over to light sleet this evening, then snow as the rain/snow line moves south. There is a window of a few hours for this changeover to occur with light accumulations possible across west TN, northeast AR, and the MO Bootheel. One caveat is the area of instability over central AR, highlighted by the thunderstorms near Little Rock. This could sure wreak havoc with precip type. This precipitation is expected to end from northwest to southeast beginning after 03z, but if forced ascent continues as the dry air aloft arrives, the drying of the dendritic growth zone could result in a period of light freezing drizzle. Confidence remains low in this scenario, but the potential does exist. As far as winter weather headlines, the snow/sleet accumulations are currently expected to remain below advisory criteria, so the SPS will be updated to reflect recent changes. It would not be surprising to see an advisory needed eventually this evening, but we`ll have to see how this system evolves over the next few hours. The other issue is the very cold air. The combination of record cold temperatures and strong north winds will push wind chill readings into the single digits and teens late tonight and early Tuesday. With temperatures only warming into the upper 20s and lower 30s tomorrow, wind chill values will remain in the 20s throughout the day. Also, a few flurries cannot be ruled out tomorrow as the very cold air aloft overspreads the region. Winds will become light under clear skies on Tuesday night. This will promote strong radiational cooling, supporting overnight lows in the mid teens to near 20 degrees Wednesday morning. Again, we`re looking at record temperatures during this period. Fortunately, a moderating trend is anticipated throughout the remainder of the week, despite a reinforcing cold front on Thursday. This system looks to be too dry to support rainfall, with precipitation confined to areas closer to the Gulf coast. Dry weather will persist through the weekend as short-wave ridging affects the lower MS Valley. Both the GFS and ECMWF ensemble suites indicate a high likelihood of dry weather during this period. The deterministic runs depict a deep trough swinging across the MS Valley late Sunday into Monday. This may be the next opportunity for precipitation, but chances remain low at this time. MJ && .AVIATION... 00Z TAFs Primary concern remains precip type through 06Z. 00Z TAFs reflected surface reports north of JBR, into western KY, with predominate precip type a mixture of sleet and light snow. NAM Bufr soundings continued to show a greater potential for -FZDZ than -SN after 03Z, but the RAP soundings appear to be more consistent with observed precip type. This would suggest the RAP depicting less pronounced elevated saturated warm air is more correct, and supportive of sleet / mixed with light snow. The main shortwave energy driving the precip will have partially lifted out by 03Z, with lower precip rates at MEM by the time freezing surface temps arrive. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Wind Advisory until 3 AM CST Tuesday for Clay-Craighead- Crittenden-Cross-Greene-Lee AR-Mississippi-Phillips- Poinsett-St. Francis. MO...Wind Advisory until 3 AM CST Tuesday for Dunklin-Pemiscot. MS...Wind Advisory until 3 AM CST Tuesday for Coahoma-DeSoto-Panola- Quitman-Tallahatchie-Tate-Tunica. Wind Advisory until 6 AM CST Tuesday for Alcorn-Benton MS- Calhoun-Chickasaw-Itawamba-Lafayette-Lee MS-Marshall-Monroe- Pontotoc-Prentiss-Tippah-Tishomingo-Union-Yalobusha. TN...Wind Advisory until 3 AM CST Tuesday for Crockett-Dyer-Fayette- Gibson-Haywood-Lake-Lauderdale-Obion-Shelby-Tipton-Weakley. Wind Advisory until 6 AM CST Tuesday for Benton TN-Carroll- Chester-Decatur-Hardeman-Hardin-Henderson-Henry-Madison- McNairy. && $$
Area Forecast Discussion
National Weather Service Marquette MI
1034 PM EST Mon Nov 11 2019 .UPDATE... Issued at 1033 PM EST MON NOV 11 2019 ...Downgraded Marquette and Gogebic counties from warnings to advisories overnight... Latest high-res models and radar/satellite trends along with available webcams suggest a diminishing trend to LES over western portions of the cwa overnight. Model soundings also support a diminishing trend in LES overnight with subsidence inversions lowering from 7kft to 5kft overnight as large scale nw flow becomes increasingly anticyclonic with sfc ridge axis building in from the west. As a result, downgraded Gogebic County warning to advisory overnight. For Marquette County, latest high-res models have backed off on western movement of dominant LES band from Alger County into eastern Marquette County. Most aggressive models from previous runs, the ARW and the Canadian, suggest only a glancing blow now from dominant LES band moving into far eastern Marquette later tonight, but then quickly shifting east out of the area by 12Z. As a result have downgraded warning to advisory for Marquette with the highest amounts (up to 4 inches) still expected over the far eastern portion of the county, near the Alger County line. && .SHORT TERM...(This evening through Tuesday) Issued at 350 PM EST MON NOV 11 2019 Current GOES imagery and radar show light multi-banding across the western UP with a more dominant band right over IWD. Across the east, there are two bands slowly becoming one as the early morning convergent band along the shore is slowly joining up with a band over Alger county. This single-banded lake-effect is creating quite the mess for some (per webcams), while others are seeing clear skies with minimal snowfall. If this scenario continues, snow totals are going to follow an extremely tight gradient across the east. Current radar Z to S shows snowfall rates just above an inch an hour in the band going over Alger county. However, I am unsure on how that is take it for what it is worth. During the last event on the 7th, it ran hot...but I trimmed the ratios off 10% and will test that with some obs tomorrow morning. Now...CAMs show quite different thoughts through tonight...leading to PoPs being a bit more broad brushed than preferred. Regional Canadian, ARW, RAP, GEM, and HRRR all show a slight western push late tonight with the primary band across the east. The duration does not look too long as winds aloft begin to back to more from the NW. There is decent timing consistency with this western shift, beginning circa 03Z tonight, before sliding back east around 09Z. The biggest uncertainty is the amount and duration of this western shift...or if it even happens. Tried to adjust PoPs and QPF to be a bit more deterministic, though given the chaotic nature of lake- effect had to spread the love around. The WRF-NMM shows a bit of a different story. It handled the development of this convergent band fairly well, but continues to move this primary band east through this evening. During the overnight hours, this primary band then breaks up into a multiband scenario on the NMM. My gut says the primary single-band is more likely given the low-level convergent wind pattern. A few of the high-res models also resolve a mesolow or two across eastern Lake Superior tonight as well, which may provide a short-term window of enhanced snowfall rates and reduced visibilities. Primary take away from all this, total snowfall amounts through Tuesday have changed from the going forecast. Have increased totals in the west, primarily near IWD given webcam and GOES trends, and decreased snowfall amounts across the east and Alger county. Overall in the west, expecting 6 to 15 inches with the 15 inches remaining in Gogebic county...slowly decreasing towards the NE through the Keweenaw. Across the east remains a bit more challenging. Where ever the primary band sets up...has the potential to bring isolated event snowfall totals up to 2 feet. More likely scenarios is a small swath of 12 to 18 inches, with isolated higher amounts. Areas outside of the primary band will come with a sharp snowfall gradient, with snowfall totals uncertain. Although there still remains a chance Marquette proper gets in on the heavier snowfalls...most likely scenario is the axis of heavier snowfall stays right along the Marquette/Alger county line, with maybe 2 to 4 inches in Marquette...depending if and how far west the band pushes. Outside of this snowfall temperatures will remain cold. Wind chills tonight in the interior could get as low as -15F with actual air temperatures right near 0F, closer to 10F near the lakes. .LONG TERM...(Tuesday night through Monday) Issued at 516 PM EST MON NOV 11 2019 The cold start to the month, featuring unseasonable cold now, will ease during the long term. Thru the first 10 days of Nov, the avg temp here at NWS Marquette is 24.4 degrees and -10.5 degrees blo normal, making this the second coldest first 10 days of November on record behind 1991. The cold has been the result of a highly amplified pattern, featuring pronounced ridging thru the ne Pacific and AK vcnty that has forced deep troffing downstream centered over roughly central N America. Over the coming days, the upstream ridge will breakdown with a strong positive height anomaly breaking off to the nw of AK and then retrograding. While there will remain a tendency for mean ridging vcnty of the w coast of Canada southward, the lower amplitude of the mean ridging and thus lower amplitude flow downstream will spell a warming trend for the Upper Lakes this week as arctic air becomes shunted n well into northern Canada with time. However, there will be one last shot of Arctic air that will just graze the northern Great Lakes Fri. Otherwise, expect temps to moderate toward normal over the next 7 days. Farther down the line, CFSv2 ensemble means have been consistently painting a picture of overall normal to above normal temps beyond this 7 days thru the end of Nov and into early Dec. As for pcpn, no significant pcpn events are on the way given nw flow trending more westerly. Although passing shortwave Wed will provide only a little -sn across the area, lake enhancement off Lake MI ahead of the wave will be a concern for headlines. Shortwave dropping thru northern Ontario Thu night and the glancing blow of arctic air will bring a brief period of some light LES off Lake Superior Thu night/Fri. Accompanied by a push of Pacific air, the next shortwave will bring some -ra/-sn late weekend. Beginning Tue night, sfc high pres ridge will quickly move across Upper MI. With low-level winds already backing sw over western Lake Superior, lingering LES will likely be pushed offshore of western Upper MI by 00z. To the e, convergent nw flow over eastern Lake Superior and inversion based around 7kft with dgz well placed in the convective layer will support some mdt snow into Luce County with a few inches of fluffy snow possible in the evening before the LES shifts offshore with backing winds. Attention then turns to low temps. There will be a window of opportunity for temps to quickly plummet before return flow and high clouds begin to increase, especially over central Upper MI. In the evening, temps could easily fall blo 0F where snow cover exists, then temps will level off and rise overnight. Consensus of raw model guidance had a good trend to base hourly temp curve on. Late in the night, winds may back just enough to bring some LES into the far se Schoolcraft/eastern Luce counties. On Wed, waa/isentropic ascent in response to the next approaching shortwave will spread some -sn across the fcst area, nothing more than a dusting to an inch given the avbl moisture and generally weak forcing. Downwind from Lake MI will be a different story. Models generally show a good signal for convergent low-level s to ssw flow up Lake MI. With 850mb temps way more than sufficient (at least -10C) for lake enhancement overtop nearly the entire length of the lake, conditions will be favorable for a dominant lake enhanced snow band to move onshore over eastern Upper MI on Wed. DGZ will tend to be displaced above or in the top portion of the lake convective layer. So, snow-to-water ratios will likely fall under 20 to 1 to provide a wetter snow. For now, expect snowfall to push 6 inches Wed/Wed evening over se Schoolcraft and se half of Luce County. If there ends up being 6-9hrs of nearly stationary convergent flow up the lake as suggested by the NAM, could easily see warning snowfall amounts upwards of 8-10 inches. Sfc trof will move across the area Wed night, shifting winds to the nw and ending the lake enhancement. Some light LES will return off Lake Superior under 850mb temps around -12C. On Thu, winds will back and waa will get underway ahead of a vigorous shortwave dropping se toward northern Ontario. If there is any light LES ongoing off Lake Superior to start the day, it will end during the morning under developing waa. High temps on Thu will push into the lower 30s. Cold front will pass Thu night, grazing Upper MI with an arctic air mass. As would be expected in such a situation with shortwave passing ne of Lake Superior, advection of dry air and a falling inversion after fropa will be negatives for any mdt/hvy LES. Might be quick burst of mdt/hvy LES along cold front as typically occurs, but falling inversion to 4kft along with drying suggests developing nw flow LES after fropa will be on the light side. Light LES will end w to e on Fri as sfc high pres moves into the Upper Lakes. Dry weather will then follow into Sat under developing waa regime ahead of the next approaching shortwave. High temps Sat will reach the 30s. Next shortwave arrives Sun, providing a chance of pcpn Sat night/Sun. Given the warming air mass, ptypes could range from -sn, -sn/-ra or even just -ra for some locations. Should dry out for Mon. Temps Mon may reach 40F in some locations. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 641 PM EST MON NOV 11 2019 NW wind driven lake-effect -SHSN will impact mainly KIWD and KCMX throughout much of the period. Highest confidence for -shsn will be at CMX and IWD with SAW remaining right along the border of conditions. Brief IFR vsbys can be expected at times during SHSN with prevailing MVFR for CMX/IWD and VFR vsbys expected at SAW. For cigs, generally MVFR conditions for CMX and IWD, with some times of IFR possible. SAW is expected to remain VFR with lake-effect SHSN remaining east; however, there is a small chance the lake-effect bands trend west which may bringing -shsn and MVFR cigs into SAW late tonight. Otherwise, gusty nw winds will continue into early Tuesday with gusts up to 20 knots at KIWD and KCMX. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 516 PM EST MON NOV 11 2019 NW winds gusting to 25-30kt should be common across Lake Superior tonight as very cold air for this time of year flows across the lake. Could be a few gale force gusts to around 35kt across s central Lake Superior from around Stannard Rock to Granite Island and Grand Island. Winds will briefly diminish from w to e Tue/Tue evening as a high pres ridge quickly moves across the area. Winds will then ramp up to 30kt from w to e Tue night/Wed morning as the high departs and a low pres trof approaches. Some gale force gusts to around 35kt will be possible. A period of lighter winds mostly under 20kt will follow Wed night. Next cold front dropping se toward Lake Superior will bring increasing winds to 30kt Thu aftn into Fri morning. Expect some gale force gusts to 35-40kt. Winds will then quickly diminish on Fri as high pres ridge arrives. As the high departs, winds on Sat will increase again to 30kt with a few gale force gusts possible. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Winter Storm Warning until 10 AM EST Tuesday for MIZ006-007-014- 085. Winter Weather Advisory until 8 AM EST Tuesday for MIZ005. Winter Weather Advisory until 10 AM EST Tuesday for MIZ002-013. Winter Weather Advisory until 6 AM CST Tuesday for MIZ009. Lake Superior... None. Lake Michigan... None. && $$ UPDATE...Voss SHORT TERM...JAW LONG TERM...Rolfson AVIATION...Voss MARINE...Rolfson
National Weather Service Raleigh NC
900 PM EST Mon Nov 11 2019 .SYNOPSIS... A cold front will approach the Appalachians from the west tonight, then cross central North Carolina Tuesday morning. This will usher in chilly arctic air for Tuesday afternoon through Thursday. && .NEAR TERM /THROUGH TONIGHT/... As of 900 PM Monday... 01Z/8pm surface analysis depicts the primary cold front now approaching the far western slopes of the central Appalachians with moderate to strong southwesterly flow continuing out ahead of the boundary. Temperatures continue to fall slowly across central NC, being limited greatly by an encroaching mid to upper-level cloud deck now spreading northeast into the foothills/piedmont of NC. Expect temps around midnight to be near 50 and holding before they begin falling into the 40s in response to the light shower activity arriving over the western Piedmont, which should remain patchy at first in the weak warm advection regime. Shower activity will then increase before spreading east after sunrise, with the arrival of deeper 60-90m height falls and the associated cold front. have trended the POPs more aggressive at the onset Tuesday morning around dawn. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... As of 245 PM Monday... A strong upper level trough, accompanied by 60-90m heights falls and an arctic front will impact the area on Tue. Ongoing rain across the Piedmont Tue morning will move east toward the coastal plain by early afternoon, exiting the CWA prior to 21Z, as the s surface cold front surges across the area and ushers in a bitterly cold airmass for Tue evening. Models continue to be in pretty good agreement on the timing of precip and qpf, generally around 0.5", with an area of locally higher amounts closer to 0.75" possible from the Triangle ne toward the VA border. These higher amounts seem to be in response to strengthening FGen as the post-frontal cold air, initially slowed by the mountains, collapses se and strengthens the temp gradient in concert with arrival of best DCVA and right entrance region of the upper jet. It`s also in this period where cold advection pushes thermal profiles sub-freezing aloft and precip rates may be high enough to allow some (initially) sleet and snow to mix in with the rain. Latest HRRR simulated reflectivities show enhanced values suggesting some bright banding, and interestingly followed by lake effect showers off the larger local lakes. The duration of any mixed precip will be short enough, before drying aloft ceases all precip, and the ground warm enough to not cause any travel issues. Areas from Roxboro to Roanoke Rapids seem most likely to see this brief mix, which is consistent with a couple HREF members. Temps that start out in the 40s west or climb into the 50s east will fall from late morning onward, reaching the low to mid 20s Tue night (see Climate section below for records). Blustery northwest winds of 15kt gusting to 25kt in the afternoon will usher in much drier air, helping to eliminate any black ice issues. Winds will decrease to 5- 10kt overnight but will also push wind chills into the teens by Wed morning. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... As of 230 PM Monday... Dry but chilly weather for Wednesday through at least Thursday afternoon as high pressure builds in behind Tuesday`s front. With low level thicknesses bottoming out around 1270m on Wednesday, highs on Wednesday will only climb to the lower 40s, with locations north of I-85 remaining in the upper 30s. Lows Wednesday night in the lower to mid 20s. Temperatures will begin to moderate on Thursday as the high moves offshore and flow aloft backs to SW. Highs on Thursday still 10+ deg below normal though...upper 40s NW to lower 50s SE. The GFS and ECMWF are in fairly decent agreement that by late Thursday, the trough currently over the Baja region will merge with a northern stream short wave digging south across the TN Valley. The combination of these features, as they move east and northeast, will spread cloudiness and rain northeastward across the central and eastern Carolinas beginning as early as Thursday evening/night, with a fairly wet period mainly east of the Triad during the daytime Friday and Friday night. While the aforementioned northern stream short wave is forecast to close over the Southeast while slowly moving eastward, it looks like that will happen just far enough east to keep the bulk of the precip east of I-95 for the period Saturday afternoon through Sunday. In terms of p-type Thursday night into Friday...right now it looks like there`s simply not enough cold air involved with this system to warrant concern for anything other than rain, esp given that the coldest air and northern stream is detached and located well to our north while the aforementioned closed low is moving across the Carolinas. However and as always...we`ll continue to closely monitor trends in the guidance. && .AVIATION /00Z TUESDAY THROUGH SUNDAY/... As of 620 PM Monday... High confidence in VFR conditions through the first 9 hours of the TAF period with passing high clouds and southwest winds around 5 kt. A strong cold front will bring rain from west to east (10-14Z) across local terminals. Continued with inherited IFR ceilings at RDU/FAY/RWI, but went with MVFR ceilings at INT/GSO as it appears that heavier precipitation will fall east of the Triad and that deep moisture should not make it quite as close to the ground. However, ceilings temporarily dropping an additional category at any terminal cannot be ruled out, but confidence is not high enough in timing to include in TAFs at this point. Rain should come to an end between 17- 21Z from west to east, with northwesterly winds 10g20kt at all sites. High confidence that ceilings should rise to VFR with departing rainfall. Looking beyond 18z Tue: VFR conditions will continue Tue evening, with nw winds that will eventually decrease to 5-10kt overnight. Sub- VFR conditions with a chance of rain will return late Thu night into Fri as a disturbance tracks NE over the Southeast coast. && .CLIMATE... Some record minimum and low-maximum temperatures for this week may be in jeopardy. DATE RDU GSO FAY Min Low Max Min Low Max Min Low Max 11/12 22 1957 44 1895 17 1943 42 1934 21 1957 39 1987 11/13 23 1977 39 1911 22 1977 35 1907 23 1911 43 1976 11/14 20 1977 39 1976 19 1986 38 1904 23 2013 45 1997 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Smith NEAR TERM...JJM/Smith SHORT TERM...Smith LONG AVIATION...Smith/Green CLIMATE...RAH
Area Forecast Discussion
National Weather Service Tallahassee FL
902 PM EST Mon Nov 11 2019 .UPDATE... Cold front is located across northern MS moving southeast and at a good steady pace. HRRR has a good handle on it and advertises it to enter our SE AL counties in the predawn hours. Clouds will increase overnight ahead of the front with light winds. Some light rain has developed off the Gulf into our area so the only real change I made was to bring PoPs further east. Otherwise, forecast is in good shape. && .PREV DISCUSSION [616 PM EST]... .NEAR TERM [Through Tonight]... Clouds will increase rapidly tonight as a strong cold front approaches the area. Rain will accompany the front and likely reach the western border of the forecast area within a couple of hours of sunrise. With limited instability, thunderstorms do not appear likely. .SHORT TERM [Tuesday Through Wednesday Night]... The strong cold front will clear the area during the day on Tuesday with gusty winds and falling temperatures during the day behind it. Strong cold advection on Tuesday night is expected to result in a light freeze across the northern and western portions of the area by Wednesday morning. In addition, since winds will stay somewhat elevated overnight, wind chill values will reach the low to mid 20s across the northwest portions of the area Tuesday night. Despite mostly sunny skies on Wednesday, high temperatures are expected to remain in the 50s across the area with a cold airmass in place. This sets up another chilly night on Wednesday with overnight lows dipping close to freezing again across the northern portions of the area. .LONG TERM [Thursday Through Monday]... Models are in general agreement that an area of low pressure will develop along the Gulf coast in association with another upper level shortwave towards the end of the week. Some timing and intensity differences remain in the guidance, but a chance of rain appears to return at the end of the week. .AVIATION... [Through 00Z Wednesday] Cold front still on track to pass over the terminals tonight into Tuesday. Used the latest HRRR for timing of the front, with shift and gusty winds behind the front, timing of precipitation, and cloud decks both ahead and behind the front. Expect some MVFR cigs ahead of the front with IFR/MVFR cigs and vsbys along and behind the front and associated with rain. Gusty winds are expected behind the front with speeds of 20-25 knots. Instability is low so expecting mainly rain. .MARINE... A strong cold front will move through the area on Tuesday. Advisory conditions will occur across the entire area behind the front. Gusts will reach close to gale force, especially across the western waters. However, nearly all of the model derived wind gust guidance keeps frequent gale force gusts west of the area, and forecast soundings from BUFKIT show momentum transfer wind gust potential mostly in the 30-33 knot range across our waters. Thus, we`ll hold off on a gale warning for now. Winds and seas will remain elevated through at least Wednesday. .FIRE WEATHER... Red flag conditions are not expected for the next several days. .HYDROLOGY... There are no flooding issues expected for the next several days. Rainfall amounts through Tuesday are expected to be fairly light. There is more uncertainty with the potential Gulf low at the end of the week, but area rivers are still running low overall and flooding is unlikely from that system as well. .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 57 69 35 56 41 / 20 70 10 0 10 Panama City 59 70 35 57 44 / 60 80 0 0 0 Dothan 49 59 29 51 35 / 60 80 0 0 0 Albany 54 61 32 51 36 / 30 90 10 0 0 Valdosta 56 70 33 53 40 / 10 70 10 0 10 Cross City 59 77 40 59 47 / 0 70 20 0 0 Apalachicola 64 72 38 58 46 / 20 80 10 0 10 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...Freeze Watch from Tuesday evening through Wednesday morning for Calhoun-Central Walton-Gadsden-Holmes-Inland Bay-Jackson- Liberty-North Walton-South Walton-Washington. GA...Freeze Watch from Tuesday evening through Wednesday morning for Baker-Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook- Decatur-Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes- Miller-Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas- Tift-Turner-Worth. AL...Freeze Watch from Tuesday evening through Wednesday morning for Coffee-Dale-Geneva-Henry-Houston. GM...Small Craft Advisory from 10 AM Tuesday to 1 PM EST Wednesday for Apalachee Bay or Coastal Waters From Keaton Beach to Ochlockonee River FL out to 20 Nm-Coastal Waters From Ochlockonee River to Apalachicola Fl out to 20 Nm-Coastal waters from Suwannee River to Keaton Beach FL out 20 NM- Waters from Suwannee River to Apalachicola FL from 20 to 60 NM. Small Craft Advisory from 6 AM Tuesday to noon CST Wednesday for Coastal waters from Mexico Beach to Apalachicola FL out 20 NM-Coastal waters from Mexico Beach to Okaloosa Walton County Line FL out 20 NM-Waters from Apalachicola to Mexico Beach FL from 20 to 60 NM-Waters from Mexico Beach to Okaloosa Walton County Line FL from 20 to 60 NM. && $$ UPDATE...Scholl NEAR TERM...DVD SHORT TERM...DVD LONG TERM...DVD AVIATION...Scholl MARINE...DVD FIRE WEATHER...DVD HYDROLOGY...DVD
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Tuesday) Issued at 200 PM CST Mon Nov 11 2019 The coldest air of the season settles in tonight with lows flirting with daily records. Synoptically-driven snow bands have departed the forecast area with an area of N-to-S oriented HCR CU noted ahead of the H700-500 trough axis just entering north-central Kansas. Satellite imagery, forecast soundings, and surface observations all show that these bands are very shallow in nature and aside from the cloud cover and periods of flurries, these bands will be of little impact. These HCR bands should dissipate later this afternoon with the loss of solar insolation. Strong northerly winds should likewise lessen this evening as the pressure gradient relaxes and decoupling takes place. RAP forecast soundings do hint that the BL may remain mixed well into the late evening hours in east-central KS owing to differential CAA, producing gusts up to 20 kts at times. A 1045 mb Canadian high pressure ridge stretching from western Kansas to central North Dakota settles over the area tonight under strong northwesterly flow on the backside of an H500 shortwave trough. The center of the high passes south of the forecast area with the ridge axis bifurcating the forecast area at sunrise. MOS- based guidance solutions plummet lows into the single digits above zero tonight with wind chill values around 0. Webcams show the snowpack over the north being patchy in nature and it is unknown how much this will contribute to lows tonight, therefore did not deviate much from the going forecast. Return flow sets in on the backside of the ridge on Tuesday afternoon under clear skies, but temperatures will be slow to respond and highs will still linger in the 30s. .LONG TERM...(Tuesday night through Monday) Issued at 200 PM CST Mon Nov 11 2019 Near seasonal temperatures return to the forecast for the end of the week with little in the way of sensible weather. An active northwest flow pattern will usher in the next shortwave trough diving southeastward into the central U.S. late Tuesday into Wednesday. The latest 12Z medium range solutions have shifted southward with the mesoscale and kinematic forcing associated with this complex, but given the poor moisture profiles have held off on introducing PoPs with this forecast update. The trailing 1025 mb surface high center is progged to stay north of the forecast area, allowing for a downslope modified airmass to quickly work into the region by Thursday afternoon. Longwave ridging translates eastward over the central CONUS for late in the week, keeping southerly flow/WAA in place into the weekend. The next chance of precip comes on Sunday as a high-amplitude trough digs south on the backside of the ridge. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 543 PM CST Mon Nov 11 2019 Expect VFR conditions for the next 24 hours. The gusty north winds will slowly diminish through the late evening hours and into early Tuesday morning. && .CLIMATE... Issued at 200 PM CST Mon Nov 11 2019 Record Lows for 11/12 ---------------------- Topeka: 7 (1911) Concordia: 4 (1911) && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Skow LONG TERM...Skow AVIATION...Gargan CLIMATE...Skow