Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/04/17


Area Forecast Discussion
National Weather Service Gaylord MI
1145 PM EDT Fri Nov 3 2017 .UPDATE... Issued at 1021 PM EDT Fri Nov 3 2017 Upstream warm front continues to slowly lift NE toward the Western Great Lakes region late this evening. Elongated area of mainly stratiform precip continues to develop north of this boundary... currently stretching from the Dakotas thru Minnesota and into Wisconsin. Some mid level returns have developed eastward into our CWA per latest KAPX 88D base ref loop...resulting only in an increase in mid level cloudiness but no precip reaching the ground as of yet. This will certainly change as we head into the overnight hours as deeper moisture and better isentropic ascent develop eastward into our CWA. Latest NAM and RAP both suggest arrival of precip will generally hold off until after 06Z...which matches well with latest upstream radar trends. Still expect the majority of precip overnight will initially be of the frozen variety...and will then become increasingly mixed with and eventually change to rain on Saturday. Still expect an inch or two of wet snow overnight mainly for the northerly half of our CWA. && .NEAR TERM...(Tonight through Saturday) Issued at 312 PM EDT Fri Nov 3 2017 ...Light snow late tonight... High Impact Weather Potential...Possible slippery roadways. Pattern Synopsis and Forecast... A strong area of surface high pressure (1033 mb) was centered over southwest Ontario. This high will move slowly off to the east tonight. Meanwhile...warm advection/isentropic ascent (I290-300K) will develop after midnight leading to a swath of precipitation to develop across roughly the northern two-thirds of the forecast area (north of M-72). Looking at thermal profiles and model soundings, this is expected to fall in the form of snow. Another surge of precipitation is then expected from mid morning Saturday through the afternoon hours. Low level cold air circulating southeast around the departing area of high pressure to the north should allow precipitation to remain all snow along and north of M-32 through around noon while a mixture of rain and snow falls to the south. A transition to all rain (and drizzle) then expected during the afternoon. Could see a total of between one and two inches of snow accumulation from eastern upper into the higher terrain of northern lower. Perhaps up to a half inch or so along the M-72 corridor before the change over to rain. Could see some slick travel Saturday morning due to the expected wet nature of the snow. Lows tonight in the upper 20s to lower 30s. Highs Saturday topping out in the upper 30s to lower 40s. && .SHORT TERM...(Saturday night through Monday) Issued at 312 PM EDT Fri Nov 3 2017 ...Mild and wet then cooler and drier... High impact weather potential...none. Split flow pattern aloft, with the more vigorous stream across southern Canada/northern US, and a weaker stream in the southern states. Surface low in the northern stream will pass well north of Superior Sunday, dragging a cold front across northern MI in the afternoon, and scooping up a southern stream low in the process. Precip and temp trends are the main concern. Warm front will be slowly lifting toward far southern lower MI Sat night, though strongest isentropic ascent across/north of that boundary will be pushing off to the east with time. Best rain chances looks to be ne lower MI in the evening, but otherwise Sat night looks to be a relative lull when it comes to precip. But the low-level airmass will be quite sludgy, so plenty of low clouds, with some fog and perhaps drizzle. Temps will be steady to slowly rising to around 40f (eastern upper) or low/mid 40s (northern lower). We may get stuck in something of a no mans land on Sunday. Best forcing will split around northern MI. Strongest height falls will be to our north, as a shortwave ejects ene-ward across Superior and points north. Another area of better forcing will be in the southern Great Lakes, where the incoming cold front and ejecting southern- stream wave interact with the leftover, stalled warm front. We do not lack for moisture, and we do see some forcing (slow lowering of 500mb heights, surface cold front. So we will probably manage to generate some showers ahead of and with the cold front, even to the point where likely pops may still be justified in the afternoon. Will also have to monitor for any sort of t-storm threat, though any real instability plume will be shunted off to our se, and we are highly unlikely to see any pre-frontal sunshine. Sunday looks to be the mildest day of the next few, with highs in the upper 40s to mid 50s. High pressure will extend from the northern plains toward the western lakes Sunday night/Monday. Much cooler air will spill back into the region behind the departing cold front. 850mb temps will dip as low as -9C over eastern upper MI by Monday, but will remain close to 0C near Saginaw Bay. Some risk for some post-frontal showers Sunday evening, especially in ne lower MI. After that, incoming airmass is quite dry, and there are some tendencies toward anticyclonic curvature, at least from time to time. So will keep lake effect precip chances quite small, mainly just a slight chance of rain and snow in parts of eastern upper MI for now. Min temps in the 30s, and max temps in the upper 30s to mid 40s. .LONG TERM...(Monday night through Friday) Issued at 312 PM EDT Fri Nov 3 2017 Coolish wx and periodic chances for light lake effect precip look to prevail in much of the extended. Best chances for precip look to be in Chippewa Co off of Superior, where cooler air and a longer upstream fetch is present. But none of this looks to be particularly high-impact, and by and large this appears to be a relatively quiet period. Max temps will be in a pretty tight range, in the mid 30s to mid 40s. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1145 PM EDT Fri Nov 3 2017 Snow will develop overnight ahead of a warm front lifting thru the Western Great Lakes region. The snow will mix with and eventually switch over to rain on Saturday as warmer air surges into the region with the passage of the warm front. Remaining VFR conditions will deteriorate to MVFR/IFR as the snow develops... with cigs holding at MVFR as the snow changes over to rain during the day. Winds will become easterly overnight and strengthen to 10 to 20 kts on Saturday with some higher gusts expected. && .MARINE... Issued at 312 PM EDT Fri Nov 3 2017 Could see a few remaining wind gusts to small craft advisory through late afternoon. Otherwise, winds should become light this evening before turning into the east late tonight into Saturday while increasing. Another round of small craft advisories will likely be needed during the day Saturday (especially on Lake Huron). && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY from noon EDT Saturday to 5 AM EST Sunday for LHZ345>349. LM...SMALL CRAFT ADVISORY from noon EDT Saturday to 5 AM EST Sunday for LMZ323-341-342-344>346. LS...SMALL CRAFT ADVISORY from 5 PM EDT Saturday to 5 AM EST Sunday for LSZ321-322. && $$ UPDATE...MR NEAR TERM...AS SHORT TERM...JZ LONG TERM...JZ AVIATION...MR MARINE...AS
Area Forecast Discussion...Updated
National Weather Service Billings MT
844 PM MDT Fri Nov 3 2017 .UPDATE... Did not make any major changes this evening as going forecast was in pretty good shape. Band of light to moderate snow was moving across western and northwest zones and was slowly advancing east as the main upper trough axis moves on shore. Most of the central zones were dry and backed off on the PoPs for the early to mid evening to reflect that. Band of moderate snow will drive east tonight and overtake most of the area overnight. For Billings, looks like the heaviest snow will be overnight and early Saturday morning. Looked long and hard at Big Horn county for potentially adding to the Winter Weather Advisory. Most models keep the heaviest snow just west (in Yellowstone county) overnight, before moving the moderate snow in during the very early morning. Latest trend of the HRRR was now sliding the moderate snow just north of the area as the jet forcing pulls away. The lates NAM was very quick with the snow window there late tonight and early Saturday. This will have to be an evolving situation that will need to see how the radar develops overnight. Right now, covered with 2 inches there with possible a last minute adjustment upward an inch or two based on how things evolve tonight. Bufkit soundings still indicating freezing drizzle tendencies overnight from Baker to Ekalaka before the cold air rushes in Saturday morning. No changes to existing highlights in place. TWH && .SHORT TERM...valid for Sat and Sun... Upgraded western advisories to Winter Storm Warnings, expanded the Winter Weather Advisories into southeast Montana. Overall was a colder day than forecast across the area. Temperatures stayed in the 20s for the most part central and west with a few lower 30s. This due to cloud cover and snow hanging in a bit longer than anticipated. Have continued to see a band of light to moderate snow along and west of a Livingston to Roundup line this afternoon, adding to some already impressive snowfall reports from this morning along the US191/12 corridors. This band is shifting northward slowly and should work out of the area over the next few hours. As this feature lifts out another disturbance will begin to generate snow over southwest zones for a period of snow late afternoon through early evening before that band diminishes and pulls northeast. The main snow event gets going later this evening as SW-NE jet intensifies over western zones then slides east, pushed by upper trof shifting eastward out of the PacNW. This feature will bring a several hours of moderate to heavy snow tonight into tomorrow as it crosses the region. Expect additional accumulations of 4 to 8 inches west of Billings, from Billings northeast toward Miles City looking at 2 to 5 inches and less than 3 inches elsewhere. Snow won`t get into the Sheridan area until around sunrise as it stands and at that point jet dynamics are beginning to weaken, so for now have kept snow accumulations light for Sheridan and Big Horn counties. For Billings tonight looks like some light snow off and on late afternoon through early evening, then a break mid evening before heavier snow develops around midnight. Heaviest snow in the Billings area looks to be between 4 and 8 AM. Issued a Winter Weather Advisory for Carter and Fallon counties for a mix of Freezing Rain/Drizzle, Freezing Fog and light snow tonight into tomorrow morning. Expect upslope fog to be dense at times with visibilities dropping below 1/2 mile at times. This poor visibility combined with slick roads will make travel very difficult across this area. The wintry mix could extend into Custer county including Miles City tonight as well, though snowfall totals are expected to be higher in this area. Snow tapers off through the day on Saturday as cold surface high pressure builds in and upper dynamics move out to the east. Mid level instability and upslope into area foothills will keep a chance of light snow going Saturday into Sunday for areas mainly west and south of Billings. Another shot of energy moves into the area late Sunday increasing snow chances once again and pulling in more cold Canadian air to start the work week on Monday. Chambers .LONG TERM...valid for Mon...Tue...Wed...Thu...Fri... Cold air and snow is expected to persist through Monday. The system does not look as dynamic as previous runs, but with colder air in place, snow should accumulate relatively easily. Weather system clears the region Monday night. Upper level ridging builds back into the region Tuesday and persists through about Thursday night. Temps will trend warmer through this period, with mid 40s by Thursday. Question marks remain as to how much snow cover will limit warming due to such variance in coverage. Some fine tuning will certainly be needed as get closer in time. Additionally, clear nights point to cold nights, so daytime highs will be further suppressed by cold starts. Models appear in pretty good agreement on timing of next unsettled period beginning Thursday night/Friday morning. Strength and impacted areas continue to differ significantly. Leaned toward wetter ECMWF for POPs as most impactful model. Expect temps to trend cooler for Friday and into the weekend. AAG && .AVIATION... Conditions should remain poor, MVFR to IFR, through the night. Overnight, another round of snow should move in to south central MT from the west and southwest, lowering visibilities. Mountains will continue to be obscured. The low conditions will continue Saturday morning and improve Saturday afternoon. RMS/Arthur && .PRELIMINARY POINT TEMP/POPS... Sat Sun Mon Tue Wed Thu Fri ----------------------------------------------------------- BIL 023/030 016/027 015/023 009/031 018/039 023/046 028/040 99/S 23/S 54/S 20/U 00/N 11/B 12/W LVM 021/032 015/031 014/025 009/032 018/040 027/047 029/045 +8/S 33/S 64/S 20/N 01/N 22/O 22/W HDN 024/031 017/032 015/027 009/033 016/041 020/048 025/043 78/S 22/S 44/S 20/U 00/U 11/B 12/W MLS 026/032 015/030 015/025 010/034 017/039 019/045 024/039 79/S 11/B 34/S 10/U 00/U 11/B 12/W 4BQ 028/036 017/034 017/027 014/037 020/044 022/049 027/041 25/O 21/B 23/S 21/U 00/U 11/B 12/W BHK 025/034 014/029 013/024 009/033 017/040 018/043 022/037 44/S 11/B 15/S 10/U 00/U 01/B 12/J SHR 026/033 016/033 015/028 010/036 014/044 021/051 025/046 38/S 52/S 23/S 20/U 00/U 11/B 12/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...Winter Storm Warning in effect until midnight MDT Saturday night FOR ZONES 28-29-34-40>42-56-63>66. Winter Weather Advisory in effect until midnight MDT Saturday night FOR ZONES 30>32-35-39. Winter Weather Advisory in effect until noon MDT Saturday FOR ZONES 33-37. Winter Storm Warning in effect until 6 AM MST Sunday FOR ZONES 67-68. WY...Winter Weather Advisory in effect from midnight tonight to midnight MDT Saturday night FOR ZONE 98. && $$ weather.gov/billings
Area Forecast Discussion
National Weather Service Charleston SC
959 PM EDT Fri Nov 3 2017 .SYNOPSIS... High pressure will linger over the region through early next week. A coastal low pressure system is forecast to develop along a cold front on Wednesday and Thursday. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Quiet conditions tonight under the influence of surface high pressure and limited moisture throughout a good part of the vertical. There is a very weak impulse that will move off the SC coast, with a more pronounced short wave that will move through the TN valley, but that`s heading more toward FL than our region. Other than a little patchy mid and high clouds overnight, skies will be clear, with excellent viewing of the Full Beaver Moon at 123 AM Saturday. Despite a decoupled atmosphere, since temps and dew points are about 1-3F warmer than 24 hours ago, we don`t foresee minimums any lower than mid and upper 50s inland from US-17 and lower 60s along the shoreline, in downtown Charleston and near the edges of Lake Moultrie. Fog potential is low since most places will not achieve their cross-over temps and the SREF and HRRR show nothing. But some ground fog is certainly possible, especially near bodies of water such as marshes, rivers and swamps. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... Saturday, short range guidance indicates that the forecast area will remain between ridging high pressure over the western Carolinas and an inverted sfc trough off the SE coast. The region of isentropic lift over the cold air damming will gradually spread east across the Midlands. Given the shallow lift, clouds may increase to partly cloudy over the inland counties. Otherwise, the forecast will feature light east winds and dry conditions. High temperatures is expected to range between 80 to 85 degrees. Saturday night, GFS indicates that sfc high pressure will spread across the CWA as the sfc trough slides west toward to SC/GA coast. This pattern should support light NE winds after midnight. A few showers are possibly over the eastern extreme of the offshore GA waters during the late night hours. In addition, GFS forecast sounding show the boundary layer becoming nearly saturated during the predawn hours, patchy to areas of fog is possible. Otherwise, conditions should remain dry will gradually increasing cloud cover. Low temperatures in the upper 50s will be common across the forecast area by daybreak Sunday. Sunday into Monday, H5 590+ Dm ridge centered over the lower Rio Grande Valley will ridge NE across GA/SC. At the sfc, a cold front is expected to track from the Ohio River Valley east to the mid Appalachian Mountains. Light NE winds on Sunday should veer slowly from the SE as the cold front approaches from the west. This pattern should favor the development of late night to early morning fog both Sunday and Monday. High temperatures should remain in the low to mid 80s through the period. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... Dry and unseasonably warm conditions will linger across the CWA on Tuesday. Medium range guidance shows a cold front sliding slowly SSE across the region on Wednesday into Wednesday night. Uncertainty in the forecast increases late Wednesday night through Thursday as the GFS and ECMWF show differences in the position of the front and development of cyclogenesis. The 12Z ECMWF indicates an amplified H5 shortwave rippling across Southeast, rapidly developing a sfc low off the NC coast on Thursday. The 12Z GFS has a much stronger Canadian high pressure reaching the Mid West by Thursday. The sfc cold front over the CWA is quicker reaching the coast, with the sfc low developing further offshore. I will use a blend of the ECMWF and GFS, but will give favor to the ECMWF. Scattered showers should exist across the region Wednesday through Thursday. Wednesday may remain mild with temperatures cooling near normal for Thursday and Friday. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... VFR. Cannot completely rule out some shallow ground fog late tonight through the middle of Saturday morning, but chances are low. Extended Aviation Outlook: VFR conditions are expected at both CHS and SAV terminals into early next week. However, there is a low chance of late night/early morning ground fog each day. && .MARINE... Variable winds at or below 5 or 10 kt expected through tonight as high pressure remains overhead. Land breeze circulations will back winds to N`erly by daybreak Saturday. Seas no more than 2 or 3 ft, mainly due to a E`erly 9-10 second swell. Saturday through Wednesday: High pressure will provide steady NE winds around 10-15 kts across the marine zones this weekend. Wave heights are forecast to range from 2-3 feet within 20NM, with 4-5 feet beyond 20 NM. A cold front will slowly approach the region through early next week, winds and wave heights will decrease Monday and Tuesday. The cold front will approach the region on Wednesday and pushing east late Thursday. Conditions will deteriorate as cold air punches over coastal waters behind the front. Winds/seas could approach marginal Small Craft Advisory levels over northern South Carolina waters and offshore Georgia waters late next week. && .TIDES/COASTAL FLOODING... The November 4 full moon/spring tide and subsequent November 6 Perigee will combine to produce elevated astronomical tides this weekend into the middle of next week. Sunday morning looks to be the most likely time for a Coastal Flood Advisory due to higher onshore winds, but the Saturday morning tide will also be close especially along the SC coast. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM...NED LONG TERM... AVIATION... MARINE... TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Cheyenne WY
500 PM MDT Fri Nov 3 2017 .UPDATE... Issued at 452 PM MDT Fri Nov 3 2017 A few changes to the forecast. Looking at a prolonged snow event for the Snowy and Sierra Madre Ranges this weekend into Monday. Latest WPC snow forecast for these areas showing close to 2 feet of snow through Monday. Going to be a big weekend out there for Elk hunters, so there will be folks out there. Wanted to get the heads up for them that it may not be too good for them over the weekend. Went with a Winter Storm Watch. Second...High winds at Arlington. They already hit a few times out there today with Craig to Casper gradients at 43/38mtrs at 850/700mbs respectively. Latest high wind guidance showing these gradients increasing tonight up to 50/49mtrs after 06Z. Decided to issue a High Wind Warning for WY-110 as a result. Updates have been sent. && .SHORT TERM...(This evening through Saturday) Issued at 222 PM MDT Fri Nov 3 2017 Low clouds have eroded over most of the CWA this afternoon but still hanging on from about Alliance to Sidney. The erosion should stop by evening then clouds likely will edge back westward overnight as southerly winds return moisture. A little fog possible over the southeast part of the Panhandle later tonight into Saturday. Rest of the plains should see more of a westerly component to the winds limiting cloud formation. Saturday looking mainly dry and mild with even some max temps attaining 70 over parts of the Panhandle. It will be rather windy especially over southeast Wyoming by Saturday afternoon and could get close to some high wind gusts out west given the favorable swly wind direction. Overall threat looks low enough to preclude a watch at this time however. Dry into Saturday afternoon then some showers should begin increasing mainly over the higher mtns by late in the day as increasing moisture rides up the west-facing slopes. .LONG TERM...(Saturday night through Friday) Issued at 222 PM MDT Fri Nov 3 2017 next cool front will push across the area Saturday night while a shortwave swings across the northern plains. Rain and snow showers should occur mainly over western and northern parts of the CWA saturday night then be confined mostly to the mtns Sunday. More unsettled weather should be over the CWA Sunday night into Tuesday as the upper jet shifts over the region and several weak impulses ride across in west-southwesterly upper flow. Still looking like some decent total snowfall over the higher mtns by early Weds with several shots of enhanced pcpn with the impulses. Over the plains a stronger push of colder air should arrive late Monday with the most widespread snow over the CWA Monday night and Tuesday. The upper trough then passes by early Weds with drier and warmer conditions in its wake to close out the week. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 452 PM MDT Fri Nov 3 2017 Stratus was slow to break out in the Panhandle this afternoon as winds stayed southerly to southeasterly. Expect the lower ceilings to return tonight after sunset. Used latest HRRR as guidance, bringing lower ceilings into KSNY...KBFF and KAIA late evening. Believe this will hold through sunrise Saturday before winds shift more westerly. Strong winds for KRWL and KLAR Saturday late morning into the afternoon hours. && .FIRE WEATHER... Issued at 222 PM MDT Fri Nov 3 2017 Overall concerns look to be low, especially from Sunday into next week as a wetter and cooler weather pattern sets up over the region. For Saturday it will be breezy to windy over much of the area and there will be some elevated fire weather conditions over extreme se Wy as afternoon humidities fall close to 20 per cent and winds gust up to 35 mph near the Laramie Range. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Winter Storm Watch from Saturday evening through Monday afternoon for WYZ112-114. High Wind Warning from midnight tonight to 3 PM MDT Saturday for WYZ110. NE...None. && $$ UPDATE...GCC SHORT TERM...RE LONG TERM...RE AVIATION...GCC FIRE WEATHER...RE
Area Forecast Discussion
National Weather Service Houston/Galveston TX
950 PM CDT Fri Nov 3 2017 .UPDATE... Minor changes to the forecast package this evening mainly to account for trends in both temperatures and dew points. Raised temperatures by a few degrees to match observations which were a tad warmer. Model guidance has been running a touch on the cool side compared to observations. Therefore, decided to raise tonight`s low temperatures by a few degrees to account for these trends, and anticipating temps to fall into low 70s across the region. These forecast low temperatures are approximately 15-20 degrees above normal climatological low temperature values for early November. Areas of fog still expected across the region as we move into the early morning hours of Saturday. With dewpoints still forecast to reach into the low 70s overnight, the gap between the temps and dew points will begin to narrow. Additionally, after 06Z surface winds should lower to 5 mph or lower. These conditions will hold for much of the morning hours, and should begin to burn off around 14Z Saturday morning. Surface high pressure will continue to edge in from the east thorough out the day Saturday. This will act to enhance subsidence over the region. Short term guidance such as the HRRR and RAP13 are picking up on the slight chance for a few stray showers late Saturday morning into the afternoon. Based off our forecast soundings as well as global guidance, not confident enough to include this slim chance for a passing shower or sprinkle in the forecast for now. Regardless, another day of abnormally warm and humid conditions will prevail Saturday with high temperatures reaching into the mid to upper 80s across Southeast Texas. Hathaway && .PREV DISCUSSION... /ISSUED 640 PM CDT Fri Nov 3 2017/ AVIATION... VFR conditions are expected to prevail this evening with another round of MVFR stratus with temporary drops to IFR occurring again overnight. Expect ceilings to lift to MVFR by late morning and VFR by early afternoon with heating. Ample near surface moisture and south to southeast winds 10 knots or less through the period will result in patchy fog formation again overnight, but have low confidence in enough nocturnal cooling occurring to produce any visibilities below MVFR. Expect any fog that develops to lift between 14-16Z. Huffman PREV DISCUSSION... /ISSUED 344 PM CDT Fri Nov 3 2017/ DISCUSSION... Isolated showers and very warm temperatures are expected through the remainder of this afternoon. Isolated showers were developing mainly along and south of the Interstate 10 corridor. The showers will be fairly shallow given the rather large cap around 850 mb. The HRRR and Texas Tech have the isolated showers ending between 5:00 and 7:00 PM. A very warm weekend is in store for Southeast Texas. The upper ridge over the Rio Grande Valley will help keep a decent cap in place. Daytime highs will be up to ten degrees warmer than normal through Monday. Tuesday will see warmer than normal but some moderation is expected as the cloud cover increases ahead of the next storm system that will is expected to move through the Southern Plains into the state. A cold front will move through the area late on Tuesday night into early Wednesday morning. A model consensus shows best chances for rain occurring along and behind the frontal boundary Tuesday night and Wednesday. Below normal temperatures are expected across the area by Thursday. 40 MARINE... Light to moderate south winds will persist until the next cold front approaches around the middle of next week. Forecast models are in a little more agreement with the front pushing off the coast late Wednesday with northerly winds behind it. Overpeck && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 71 86 69 87 68 / 10 10 10 10 10 Houston (IAH) 71 87 71 85 70 / 10 10 10 10 10 Galveston (GLS) 74 84 73 82 74 / 10 10 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ Update...08
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1020 PM EDT Fri Nov 3 2017 .UPDATE... Issued at 1020 PM EDT FRI NOV 3 2017 Issued an update to the forecast to adjust the pops across the far east a bit lower as a few isolated showers are lingering but are few and far between. The isolated showers should dissipate after 06z before the mentioned warm front lifts north towards and just after dawn. Also, with the rain earlier and despite the cloud cover some fog is beginning to develop so went and put some patchy fog in the grids. A new zfp was issued for this update. UPDATE Issued at 710 PM EDT FRI NOV 3 2017 Issued an update to the forecast to input the latest observations this evening and trend them into tonight. In addition, with drying conditions, have lowered pops as showers are dissipating across the area. Also reintroduced pops towards dawn as a warm front develops and lifts northward. && .SHORT TERM...(This evening through Saturday night) Issued at 310 PM EDT FRI NOV 3 2017 18z sfc analysis shows a low pressure wave moving through southeast Kentucky along a well defined boundary. This is taking the bulk of the convection east and out of the area this afternoon, though some lighter returns remain back to the north and west. Temperatures vary across the boundary this afternoon ranging from the upper 50s in the far northwest to the mid 60s through the southeast. Dewpoints are not far from dry bulb temperatures across the area while southwest winds of 5 to 10 mph are found southeast of the front and northwest winds at similar speeds are noted to the northwest. The models are in good agreement aloft through the short term portion of the forecast. They all depict fairly fast and zonal flow through the southern Ohio Valley tonight into Saturday. Within this flow, ripples of energy will pass generally south of the area while a weak and dampening wave moves by to the north on Saturday afternoon. The flow remains benign at mid levels into Sunday morning taking on a slight southwesterly cant. Given the model agreement, have favored a general blend of the near and short term guidance with a strong lean towards the higher resolution HRRR and NAM12 along with the latest radar trends. Sensible weather will feature a damp and mild night, even if pcpn chances and QPF are rather low. As such, have dropped the thunder from the grids for tonight and into Saturday morning. The boundary does move back north as a warm front later tonight leaving eastern Kentucky in the cloudy warm sector for Saturday, but limited instability due to those clouds, lack of a trigger, and better mid level energy staying to the north will keep PoPs in the low chance category without a thunder mention. Saturday night should be similar to tonight with only limited potential for radiational cooling due to the clouds and moisture staying in place. For both tonight and Saturday night, expect the clouds to keep the fog from becoming too much of an issue. Again used the CONSShort and ShortBlend as the starting point for the foundation grids through the short term. Only made a few minor spot/point changes to the temperatures through the forecast given the high level of moisture. As for PoPs, did bring them up from the floor for tonight and Saturday - not ready to keep them so low given the environment and our position related to low pressure and warm front. .LONG TERM...(Sunday through Friday) Issued at 332 PM EDT FRI NOV 3 2017 Mid level heights will peak over the area on Sunday with good southwesterly flow. This will send highs well into the 70s during the afternoon, making for a nice end to the weekend. Wet weather will return late Sunday night into Monday as a cold front upstream moves into the region. Convection will likely develop Sunday evening to our northwest with this activity pushing southeast into eastern Kentucky late Sunday night into early Monday morning. While the activity should gradually be diminishing with time as it outruns the better instability, could still be a few thunderstorms as this activity moves into the region. Not expecting a severe threat with the lack of instability over the area. This activity will move on out by mid to late afternoon, with a lull expected in precipitation. However, a quick moving shortwave will quickly push across the area Monday night, bringing a swath of showers to the area. This wave will ride across the stalled out frontal zone and could produce a quick half inch to inch of rain across the area before departing by early Tuesday morning. Dynamics are strong enough with this system to yield some small potential for thunderstorms, but again, no severe storms anticipated. This wave will push the stalled boundary to our south by Tuesday with the better rain chances shifting to our south. A secondary shortwave may bring another chance of rain Wednesday night, but models are trending southward with this system, so only a small chance of rain to cover this wave across our south into Wednesday night. Weather dries out for the remainder of the week, but much colder air will settle in over the area for the remainder of the week. This will bring temperatures back to more seasonable levels. However, as high pressure builds in late in the week into the following weekend, we may see temperatures start to warm again. However, weather should be dry for the second half of the week. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) ISSUED AT 710 PM EDT FRI NOV 3 2017 The main concern for aviation through tonight is the passage of the front and what ceilings will push through with it. Once the front passes through, cigs will lower to field mins and remain through the night and into midday. As a warm front lifts north late tonight and into tomorrow, showers will develop into the area again dropping cigs to mvfr or just above. Winds will remain light and variable after the frontal passage. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SHALLENBERGER SHORT TERM...GREIF LONG TERM...KAS AVIATION...SHALLENBERGER
Updated for 00Z Aviation Forecast Discussion below.

&& .PREV DISCUSSION... /issued 635 PM CDT Fri Nov 3 2017/ UPDATE... Updated to raise PoPs and tweak overnight temperatures. DISCUSSION... Forecast largely on track with only minor adjustments needed to PoPs as convective trends and CAM guidance suggest rain will remain primarily confined to our southwest area. Tweaked overnight temperatures down a couple degrees based on trends. WLC PREV DISCUSSION... /issued 329 PM CDT Fri Nov 3 2017/ DISCUSSION...Surface analysis this afternoon places a surface low near Fort Smith Arkansas with a trailing cold front extending south into Texas. A quasi-stationary boundary also stretches from Middle Tennessee back through North Mississippi and through Arkansas. Regional WSR-88D radar trends show showers and thunderstorms over portions of North Mississippi and East/Central Arkansas. As of 3 PM CDT, temperatures across the Mid-South range from the 70s to lower 80s over North Mississippi and 60s north of the front. Additional showers and thunderstorms are anticipated tonight, especially south of I-40 as a shortwave trough over Arkansas moves across the Mid-South. Latest mesoanalysis indicates 1500-2000 J/kg, LI`s between -4 to -5, and 0-6 km Bulk Shear values between 25 to 30 kts. There will be a potential for a few strong to perhaps severe thunderstorms over portions of East Arkansas south of I-40 and Northwest Mississippi this evening with large hail and damaging winds as the main severe weather threats. The aforementioned quasi-stationary boundary is expected to lift north later tonight with into early Saturday. Fog is anticipated to persist north of the quasi-stationary until the boundary lifts north. Shower and thunderstorm chances will linger into Saturday with the best chances mainly east of the Mississippi River. Short term model soundings indicate a capping inversion may be present on Sunday, potentially limiting rain chances. Latest long term model trends indicate another cold front will come through the region towards next Tuesday with the ECMWF slightly slower than the operational GFS, bringing a better rain chances to the Mid-South. Cooler temperatures will filter in behind the front for mid to late next week. CJC && .AVIATION... 00Z TAFs Complex aviation weather scenario for the overnight periods, behind a weakening TSRA complex to the south and southeast of MEM. The convective activity is associated with a compact and potent upper level disturbance lifting east from AR. MVFR/IFR prevailed behind this disturbance over northern AR. For MEM, IFR prevailed at late afternoon, north of a frontal boundary over northwest MS. Latest HRRR runs show this boundary becoming diffuse overnight in the wake of exited SHRA/TSRA. Driver of overnight IFR potential may be radiational cooling if mid clouds clear, in contrast to the warm advection north of a surface warm front this evening. In a nut shell, confidence in overnight CIG/VSBY is marginal, and best forecast may be the upstream METARs at early evening over northern half of AR. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service San Francisco Bay Area
900 PM PDT Fri Nov 3 2017 .SYNOPSIS...A weak cold front approaching from the northwest will generate periods of rain tonight through at least midday Saturday. Rainfall amounts will mostly be light, but brief heavy downpours are possible. Another cold front may bring additional light rain late Sunday and Sunday night, mainly to the northern portion of our region. Dry weather is forecast from Monday through most of Wednesday. A potentially stronger and wetter system may impact the region from late next Wednesday into Friday. && .DISCUSSION...As of 9:00 PM PDT Friday...KMUX radar currently shows bands of precipitation across the North Bay associated with a weak cold frontal boundary that is slowly sagging southward. Radar also shows isolated showers elsewhere across the SF Bay Area. Rain rates are mostly light, although there have been reports of brief heavy downpours near Santa Rosa this evening. Rainfall totals over the past 24 hours have generally been less than a tenth of an inch. However, locally up to a quarter of an inch has fallen in the North Bay, with up to a half inch in isolated portions of the Santa Cruz and Santa Lucia Mountains. Periods of rain will continue overnight, mainly in the North Bay, as the front continues its slow southward progression. According to the latest NAM and HRRR models, rainfall along the frontal boundary will shift south of the Golden Gate around sunrise Saturday morning. By Saturday afternoon, scattered light precipitation is mostly expected to be confined to areas from Santa Clara County southward. The frontal boundary is forecast to dissipate by late in the afternoon and precipitation will likely end in most areas by Saturday evening. Additional rainfall through Saturday evening is expected to be on the order of a tenth to a quarter of an inch. A shortwave trough currently located along the British Columbia coast is forecast to dig south through Sunday. A cold frontal boundary associated with this trough may produce additional rainfall in our area from late Sunday afternoon through Sunday night. The latest GFS and ECMWF both indicate this frontal system will wash out before reaching Sonoma County, and thereby produce little or no rainfall in our forecast area. The NAM and the Canadian, by contrast, bring a band of light precipitation into the North Bay around sunset on Sunday, with light rain reaching as far south as San Francisco and Concord by late Sunday night. Even if the NAM and Canadian verify, rainfall amounts will be very light. Tonight`s system and Sunday night`s system will bring cool air into our region. So expect a couple of chilly nights once skies clear out early next week. The coolest night will likely be Monday night when overnight lows in the inland valleys could drop into the mid 30s. Otherwise expect dry weather from Monday through most of Wednesday, along with seasonably cool daytime temperatures. The longer range models agree that a stronger and wetter system will impact our region by late next Wednesday, with the potential for periods of rain and gusty winds from Wednesday night on into next Friday. Forecast updates this evening included adjustments to timing of rain chances, and increases in overnight lows during periods of cloudy wet weather. && .AVIATION...As of 6:08 PM PDT Friday...The cold front has moved by Point Arena buoy, 00z observation showed a wind shift and slight pressure rise. The front is shallow and a slow mover at about 10 mph, forward progression being primarily building surface pressures behind the front while there`s little contribution to forward motion by nearly parallel winds aloft above the front. Both 12z/00z Oakland soundings showed a warm frontal inversion near 10,500 feet; mild, humid SW flow ahead of the cold front with weak MUCAPE 100-150 j/kg continues to converge ahead of the cold front with a mix of light to briefly moderate stratiform rain and convective rain showers per radar data. 00z tafs continue forecast of VFR/MVFR cigs, except thought is that IFR cigs and vsbys are more probable over the North Bay as the surface to lower level cold front presses into consolidating higher dewpoint air and 100-150 j/kg MUCAPE just ahead of the front. Caveat here for the overnight is that IFR cigs may spread more to the southeast across the remaining forecast area overnight if warm air advection light rain interacts with near surface cooler air advection causing more of a frontal fog scenario to develop. Vicinity of KSFO...S-SE wind 5-10 knots tonight into Saturday morning. The cold front becomes nearly stalled along the San Mateo Coast Saturday morning with best guess for wind shift to W-NW being 20z Saturday. Cigs VFR/MVFR though as mentioned if conditions become more favorable for frontal fog then visibilities may become lower than advertised in present 00z taf. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...Light SE winds ahead of a slow moving cold front that`ll reach the Monterey Bay Saturday afternoon. The 0 deg Celsius 850 mb isotherm reaches the Monterey Peninsula Sunday morning. A chilly early November air mass will steadily modify through Sunday, however expect a lowering freezing level and NAM/WRF forecasts high boundary layer RH (at least 80%), and 925 mb level RH 90-100% most likely resulting in low clouds Sunday. && .MARINE...as of 4:42 PM PDT Friday...A front will move through tonight leading to periods of light rain and showers. Southerly winds ahead of the front will become northerly with its passage. Seas will gradually increase through the weekend. A second front will arrive Sunday into Monday with increasing seas. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...None. $$ PUBLIC FORECAST: Dykema AVIATION: Canepa MARINE: Bell Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea
Area Forecast Discussion
National Weather Service Omaha/Valley NE
620 PM CDT Fri Nov 3 2017 .SHORT TERM...(Tonight through Monday) Issued at 251 PM CDT Fri Nov 3 2017 Low-level warm and moist advection is underway across the area and is evident in satellite imagery with a large area of stratus advecting northward out of Kansas. In addition, a weak mid-level shortwave currently over northeast Colorado will continue to move northeast into the region through the overnight. Areas of drizzle or possibly light rain are expected to spread across the forecast area overnight as the weak wave passes over the region. Most of the precipitation should be over by 12z with low clouds lingering a bit later. Saturday looks dry with favorable mixing to support max temperatures in the upper 50s in most areas. A short-wave trough will be sliding across south-central Canada by late Saturday allowing a cold front to drop southeast across the northern Plains and into our forecast area by late Saturday night. This could produce some light rain across our northern counties where we have 40 pops mentioned along the South Dakota/Nebraska border. Forecast soundings do keep all pcpn as rain. .LONG TERM...(Monday night through Friday) Issued at 251 PM CDT Fri Nov 3 2017 Cold air advection will be noticed Sunday as Canadian high pressure builds south across the Dakotas and into the forecast area. Max temperatures Sunday should top out in the lower 40s across our north to the lower 50s in our south. Zonal mid-level flow is expected into early next week while cool surface high pressure remains overhead. This should keep high temperatures in the 40s for the early part of the week. A quick moving short-wave trough will drop southeast through western Nebraska and into Kansas but model differences continue on strength of this trough but in any event, model solutions would still keep our area dry. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 620 PM CDT Fri Nov 3 2017 Expect deteriorating conditions this evening, trending toward MVFR and possibly to IFR for at least a few hours. MVFR ceilings had already moved into the southern parts of southeast NE as of 6 pm and should expand northward this evening. Some fog is possible but did not go below MVFR with visibilities for now. Just how fast the clouds decrease Saturday is problematic. There are varying model solutions with cloud cover, but for now tended to lean mostly toward recent runs of the RAP and HRRR. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Kern LONG TERM...Kern AVIATION...Miller
Area Forecast Discussion
National Weather Service Shreveport LA
935 PM CDT Fri Nov 3 2017 .UPDATE... Isolated showers and thunderstorms were lingering across portions of northwest LA and southwest AR tonight, courtesy of an eastward propagating upper level impulse and plentiful low level moisture. The HRRR has been most representative with the ongoing activity and as such, the precipitation will continue to push northeast across the northeast CWA whilst also waning with time throughout tonight. In its wake, computer models hint at the return of a stratus deck, in addition to patchy and possibly dense fog for some locales overnight. The sky grid has been updated to reflect the increasing cloud cover, and will maintain a mention of fog and lingering precipitation. Otherwise, the forecast is largely on track with continued above normal warmth tomorrow and dry conditions as an upper level ridge commences to near the Four- State region. Only made minor tweaks to the near-term surface temperature, dewpoint temperature and relative humidity values. && .PREV DISCUSSION... /issued 652 PM CDT Fri Nov 3 2017/ AVIATION... For the 04/00z TAFs, isolated convection will persist for the first several hours of the TAF period mainly east of a line from KDEQ to KGGG to KLFK along and ahead of a weak cold front. Rain chances should diminish from west to east by 04/06z as daytime heating wanes and an upper trough axis moves east of the region. Patchy fog and low stratus are expected during the overnight/early morning hours resulting in MVFR/IFR flight conditions. Ceilings will slowly improve after sunrise Saturday morning, but most TAF sites, with the possible exception of KMLU, should improve into the low end of VFR by 04/18z. CN PREV DISCUSSION... /issued 208 PM CDT Fri Nov 3 2017/ DISCUSSION... Cold front continues to make slow but steady progress south and east into our northwest zones this aftn. Cold front as of 18z was located near or just east of a TYR to DEQ line. Cu field in the warm sector, especially just along and ahead of the cold front is trying to show some definition on VIS Satellite but latest mesoanalysis shows that the capping inversion is trying to hang on. Expect another hour or two of heating should weaken the cap in order for some isolated to scattered thunderstorms to develop on or just ahead of the frontal boundary across portions of extreme Northeast Texas, Southwest Arkansas into extreme Northern and Northeast Louisiana. Latest meso analysis showing SBCAPE values are near 2500-3000 J/KG across SW AR into N LA. While instability remains sufficient for some strong to severe thunderstorms later this afternoon into this evening, depth of moisture continues to be unimpressive with moisture confined to only the lowest 5kft of the atmosphere. Having said low level lapse rates will approach 8 degrees across our extreme northeast zones later this aftn/evng so absolutely cannot rule out a few strong thunderstorms and/or an isolated severe thunderstorm in the 4-9pm window. Convection should quickly dissipate in coverage and intensity late this evening. The cold front will push a little further south and east this evening before stalling out and returning back to the north as a warm front Saturday morning. Have introduced the possibility of fog in the warm and cool sectors of the front after midnight and continuing through the mid morning hours for Saturday with some of this becoming dense fog in a few locations. In the wake of this disturbance tonight, upper flow becomes rather flat and uneventful across the Southern Plains/Lower Miss Valley. This will result in much above normal temperatures continuing not only during the day but at night as well. Overnight lows after tonight will range in the middle 60s to near 70 degrees through the weekend into early next week with daytime highs in the lower to middle 80s this weekend into early next week. These overnight temperatures will be some 15 to 20 degrees above normal for the first week of November with daytime highs some 10 to 15 degrees above normal. Our next weather maker in the form of a disturbance embedded in a progressive westerly flow pattern appears to begin influencing our region Wed into Thu of next week and with it will be our next good chances for rain. The trough will also put a dent in the near record heat we will see over the next 4 days but this airmass is of a Pacific origin with temperatures returning to near normal if we are lucky for the second week of November. Prelims to follow...13. && .PRELIMINARY POINT TEMPS/POPS... SHV 68 84 68 85 / 30 10 10 10 MLU 66 84 67 85 / 40 10 10 10 DEQ 55 83 63 84 / 10 10 10 10 TXK 62 82 66 84 / 20 10 10 10 ELD 63 82 65 83 / 40 10 10 10 TYR 64 84 67 85 / 10 10 10 10 GGG 64 84 66 85 / 10 10 10 10 LFK 68 84 67 86 / 20 10 10 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 29/09/13