Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/25/18

Area Forecast Discussion
National Weather Service Denver/Boulder CO
843 PM MST Sat Nov 24 2018 .UPDATE... Issued at 843 PM MST Sat Nov 24 2018 Weather is evolving near expectations. Secondary cold front is racing toward Denver at this hour. Intense snow band moved through Cheyenne but is being eroded by the low level downslope winds coming off the Cheyenne Ridge. This will limit snowfall in the downslope areas, but we still expect a few hours of snow on the upslope regions going back uphill south of I-76. This would bring some snow showers to the Denver area between 9 pm and midnight. We don`t expect sustained intensity, but there could be an impressive burst at the start for a half hour or so. Given the apparent intensity of the lift, PoPs and snowfall amounts were both raised just a bit for the couple hours as this band passes during the middle of the night. This produces a band of 2-4 inches of snow in the area we issued the winter weather advisory. Only question is if a blizzard warning would be warranted--at this point we still think the answer is no, but there could be some localized near blizzard conditions for a short time somewhere. This would be most likely in Sedgwick and Phillips counties during the early morning hours. High winds will probably only be there for a couple of hours as well with the frontal surge, then a gradual decrease overnight, so the 2 am expiration time should be good. Mountain snow also on track, generally light but with a little surge as the band of lift goes by. && .SHORT TERM...(This evening through Sunday) Issued at 322 PM MST Sat Nov 24 2018 Heavy snow moved through through the I-70 mountain corridor this afternoon, resulting in road closures on I-70 in Summit County. Meanwhile, a few rain and snow showers also spreading across the plains. Also, there was a push of stronger winds with the cold front with gusts to around 50 mph. The band of heavier precipitation will continue to push south with the front and exit our forecast area late this afternoon. Meanwhile, lighter snow continues in the mountains with sufficient orographics but thinner moisture profiles. The main concern for us exists with the evolution of the upper low, now dropping south/southeast through Wyoming. The RAP Q-G analysis is showing the strongest height fall tendency right over the Denver area so a south/southeast track is expected through the evening. As a result, the deformation zone of the upper low will also sink this way. We basically expect a lull in precipitation through early evening as moisture decreases, and then an uptick with stronger northerly flow developing as this deformation/moisture zone drops south/southeast. The strong northerly flow and farther south solution will favor orographic enhancement over the Palmer Divide and points east and northeast toward Limon, Akron, and Holyoke. Due to the combination of strong winds and more snow for this area, we`ll add a Winter Weather Advisory for snow and blowing snow and a 1 to 3 inch forecast. We`ll have to watch accumulations carefully because much more than 2 or 3 inches will produce more significant impacts due to the strength of winds. Even the eastern side of Denver should see some snow with this second batch, so have increased the PoPs with a dusting to 1" of snow expected at this time. It should be noted that very small changes to the storm track and orographic component could make for a significant difference in areas that see no snow or accumulating snow across the plains and Palmer Divide. With regard to winds, we expect another blast of high winds with gusts to 50-65 mph starting along the Front Range early to mid evening, and then spreading east and southeast across the plains. That occurs as the upper level trough axis drops across us, resulting in a very strong pressure gradient as strong height rises occur behind this system. Winds should slowly decrease overnight with lighter winds prevailing in all but the eastern plains and mountain tops by morning. On Sunday, much better travel conditions can be expected. Snow covered roads and lingering light snow showers in the mountains early in the morning will give way to some sunshine and warming by late morning and afternoon, allowing road conditions to improve. The plains will also see lighter winds, although still gusting to 30-35 mph over the eastern sections. .LONG TERM...(Sunday night through Saturday) Issued at 322 PM MST Sat Nov 24 2018 A less active pattern will dominate Colorado weather for much of the coming week. Strong subsidence will continue over the state Sunday night and Monday as an upper level ridge builds over California and the Pacific Northwest. Dry northwesterly flow aloft will cover north central and northeast Colorado. Temperatures will also moderate through the period, reaching above normal for the end of November from Tuesday through Friday. Mountain areas may see some gusty winds at times due to the moderate northwesterly flow aloft. Medium range model solutions are fairly similar through mid-week as the upper ridge flattens and flow aloft over the state becomes either westerly or west-northwesterly. Moisture is expected to begin moving back into the state on Thursday or Friday with the ECMWF and GFS models offering different solutions on the amplitude of the upper trough that is bringing the moisture to the state. Mountain areas will certainly see a return of snowfall for the end of the week, but it is too early to tell how the weather on the plains will evolve, based on the timing and amplitude of the weather system. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 843 PM MST Sat Nov 24 2018 A cold front will bring strong north winds and scattered snow showers to the Denver area between 04z and 06z. Winds will gust as high as 50 knots and there could be a quick snow shower with accumulation of up to an inch in an hour. After 06z, winds will be diminishing and the threat of accumulating snow will be much lower. Instrument approaches to KDEN should be expected between 04z and about 10z. VFR conditions are expected after that, with winds below 15 knots after 12z. && .BOU WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 2 AM MST Sunday for COZ038>051. Winter Weather Advisory until 5 AM MST Sunday for COZ030-032-041- 046-049>051. Winter Storm Warning until 5 AM MST Sunday for COZ031-033-034. && $$ UPDATE...Gimmestad SHORT TERM...Barjenbruch LONG TERM...Dankers AVIATION...Gimmestad
Area Forecast Discussion
National Weather Service Dodge City KS
730 PM CST Sat Nov 24 2018 .UPDATE... Issued at 730 PM CST Sat Nov 24 2018 ...Potentially damaging high winds tonight into Sunday morning... ...Blizzard conditions expected northern counties after midnight... We have decided to add another row of counties southward to include in the winter weather advisory for snow/blowing snow. This basically includes the US 50 corridor from Syracuse to Garden City to Dodge City. Updated all grids through 6 am Sunday, using the latest HRRR as a guide. HRRR iterations have been trending steadily southward. For instance, the main surface low was forecasted by 12z ECMWF to be near Syracuse at 6 pm/00z. In reality, it was near Elkhart in Morton county. This two county disparity will have implications on how far south snow and blowing snow will evolve tonight. Thus, the additional counties in the advisory. Kept snow amounts modest, near 1 inch along US 50, and 2-3 inches along I-70. But what snow we do get will come down intensely for a short period as the strong deformation band pivots through. Much more importantly, NW winds will be gusting 50-60 mph as the snow falls, resulting in several hours of white out conditions. Continue to feel most confident near blizzard conditions will evolve after midnight along/north of K-96. Periods of snow/blowing snow will likely make it as far south now as US 50 and Garden/Dodge. Travel will become difficult, particularly north/NE of Dodge City, after midnight. All of this is already a memory by sunrise, with snow wrapping up across the eastern counties by 6-8 am. && .SHORT TERM...(This evening through Sunday) Issued at 230 PM CST Sat Nov 24 2018 Warm, downslope flow this afternoon has aided in mild temperatures. Big changes are coming beginning tonight with very strong wind and possible blizzard conditions tomorrow morning toward our northern zones. We`ll start with wind concerns first since models have been consistent in showing this system as a high wind event. Water vapor imagery this afternoon shows a powerful shortwave over Wyoming, which will quickly move into western Kansas by Sunday morning. An attendant surface low in eastern Colorado has been deepening and edging toward Western Kansas this afternoon. This low will bring a strong cold front through the the forecast area tonight. A tight MSLP gradient of rising pressure and a pressure change couplet signaling an isallobaric response behind the front will aid in the wind becoming very strong, with gusts up to 60mph beginning tonight through tomorrow morning. Strongest wind gusts will occur tonight between roughly 7 pm and midnight, and then again behind the main low itself with strong pressure rises from 4 am through 9am. A High Wind Warning has been issued for areas roughly west of highway 283, but may need to eventually be expanded east. While temperatures overnight will drop into the upper 20s/lower 30s, the wind chill tomorrow morning will drop into the teens. What further complicates matters is the potential for rain/snow this evening. Southwest Kansas will be on the outer fringes of the heaviest snowfall during this event, with much higher totals in northeastern Kansas. Regardless, the GFS, ECMWF and high resolution models have been edging slightly more QPF into Southwestern Kansas. Rain will begin to fall tonight after roughly 9pm. How much snow will occur will depend on how quick the cold air advection rushes in and changes over the rain to snow. Have favored the HRRR and ARW colder solutions for the morning. Forecast soundings shows a lack of a warm nose, so the transition from rain to snow should be quick. While a midlevel jet will increase snow growth in the dendritic zone, the strong wind and quickly moving system should keep snow ratios at bay. Therefore have went with 1-3 inches of snow near the I-70 corridor. Unfortunately, the strongest winds and heaviest snow will occur at the same time, which will bring possible blowing snow and blizzard conditions to that area Sunday morning. At this time, have issued a Blizzard Warning for Ellis and Trego counties, and a winter weather advisory for counties just to the south. For now, areas as far south as Dodge and Garden City may see a dusting. .LONG TERM...(Sunday night through Saturday) Issued at 230 PM CST Sat Nov 24 2018 Snow will come to an end by early Sunday afternoon. Wind will finally calm down by nightfall as high pressure sets in. Temperatures overnight will drop into the 20s. Southwest Kansas looks to remain dry through the week. Temperatures will remain mild, with highs in the upper 40s to 50s. The ECMWF and GFS brings the next possible storm system through the region next weekend. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 445 PM CST Sat Nov 24 2018 VFR conditions should prevail throughout the entire TAF period for all locations. Currently, breezy south winds in the 12-15kt range ahead of a fast approaching cold front pushing in from Colorado. Winds will turn and gust initially up to 35kts after 02-03Z and into the 45-50kt range after 03-04Z out of the northwest. These winds will continue through 17-18Z before subsiding to 35kts and diminishing to less than 12kts towards sunset Sunday as night time cooling starts to occur and the pressure gradient relaxes in wake of the aforementioned cold frontal passage. Precipitation wise, HYS will see rain after 05Z before turning to snow after 09Z with all other locations not seeing any fall on station. However, uncertainty in the track southward, DDC and GCK could see light snow flurries in the 10-12Z time frame depending on how far south the track of the low occurs. Amendments may be needed as the event pushes closer over night or will show up in the new TAF cycle at 06Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 29 39 22 50 / 60 20 0 0 GCK 27 40 21 49 / 60 10 0 0 EHA 29 43 24 51 / 10 0 0 0 LBL 30 43 21 51 / 10 0 0 0 HYS 27 32 19 43 / 90 80 0 0 P28 35 40 23 51 / 20 20 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 9 AM CST /8 AM MST/ Sunday for KSZ043>046-061>066-074>081-084>090. Winter Weather Advisory from midnight CST /11 PM MST/ tonight to noon CST /11 AM MST/ Sunday for KSZ043>046-061>065-077>079. Blizzard Warning from midnight tonight to noon CST Sunday for KSZ030-031. && $$ UPDATE...Turner SHORT TERM...Reynolds LONG TERM...Reynolds AVIATION...Lowe
Area Forecast Discussion...Corrected
National Weather Service Huntsville AL
810 PM CST Sat Nov 24 2018 .NEAR TERM...(Tonight) Issued at 810 PM CST Sat Nov 24 2018 Winds have become light or very calm in many locations in northern Alabama. With only very thin high cloudiness near and just to the south of Morgan county, this has setup efficient radiational cooling which should continue for the next few hours and possibly until just after midnight. As a result, temperatures have quickly fallen down to dewpoint values and fog (some dense reducing visibilities to around 1/4 of a mile) has formed in northeastern Alabama and into Cullman county. As a strong area of low pressure moves east into Missouri towards daybreak, a strengthening low level jet developing ahead of the low should help to increase winds enough to begin dissipating fog as early as 4 or 5 AM. However, between now and 4 AM dense fog in northeastern Alabama should develop further west. How much further west and north is a bit more uncertain. At this time though, Cullman, Morgan, Marshall, Dekalb, and Jackson counties in northern Alabama will definitely experience dense fog during that period. Thus, issued a Dense Fog Advisory for those counties from 8 PM through 4 AM. Areas of fog look likely to form further west as well. However, winds and higher dewpoint depressions earlier today may be just enough to keep widespread dense fog from forming in Colbert county east into Madison county and into southern middle Tennessee. Thus, will hold off on an a dense fog advisory for those areas, but will issue a special weather statement highlighting the possibility of patchy dense fog formation for the next few hours for Madison, Lawrence, and Franklin counties in northern Alabama as well. Tweaked low temperatures down a tad into the upper 30s to mid 40s, as temperatures are already in the lower 40s near and east of I-65. These could drop a few more degrees before sunrise due to cold air drainage from the mountains of northwestern Georgia and eastern Tennessee. .SHORT TERM...(Sunday through Tuesday) Issued at 250 PM CST Sat Nov 24 2018 As has been advertised, the next system slated to arrive in the TN Valley is currently taking shape over the Intermountain West (per RAP analysis), and will shift E/SE overnight. A sfc low will develop and deepen over the OK/KS border tonight, and will track E/NE into the OH Valley by this time tomorrow. This will drag a cold front toward the area, along with showers overspreading the region late tomorrow afternoon (between 21-00Z). Much of the upper level support will remain well N of our local area tomorrow/tomorrow night, so a thunder-free forecast is anticipated. Given this system is starved for moisture, rainfall totals will remain less than 0.1-0.25". The real story with this systems passage will be the cold air that filters in thanks to NW flow aloft in the wake of the deepening upper trof to the E/NE. Temperatures will tumble into the lower 30s by Monday morning, with all of the precip having moved well E of the region before the truly cold air arrives. Daytime highs Monday will top out in the middle 40s, with temps again plummeting down into the middle 20s for Tuesday morning. Tuesday will be a near repeat of Monday, with daytime temps well below normal in the middle 40s. The only difference will be that morning lows Wednesday will be a degree or two warmer than Tuesday morning. Otherwise, a cold and dry forecast wraps up the short-term portion of the forecast through midweek. .LONG TERM...(Monday night through Friday) Issued at 250 PM CST Sat Nov 24 2018 The medium range shows greater spread and uncertainty than usual. Wednesday should be quiet with moderating flow behind a departing surface high. Thursday becomes more uncertain. The GFS & FV3 have minor differences in timing with a central Rockies shortwave; the ECMWF and GEM bring in precipitation a full day later from a completely different Rockies longwave trough. The national blend, ECMWF EPS, and NAEFS support spreading low PoPs across Thursday and Friday, but seem to skew towards the later solution. The forecast will do the same. Temperatures will moderate towards normal Thursday into Friday. Med-range models continue to advertise an amplified pattern for next Saturday, though differences in the details (tilt, depth, etc.) still exist this far out. High PoPs are warranted for this time frame but will be reduced from the blend consensus given the uncertain details, while temperatures may crack normal under persistent southerly flow. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 605 PM CST Sat Nov 24 2018 VFR conditions are expected at both terminals through approximately 3Z. Winds are already very light at KMSL and good radiational cooling is expected this evening. Winds remain closer to 5 knots at KHSV, but the air is much more moist than KMSL. This will likely set the stage from some light fog to form at times through 7Z (at KMSL) or 8Z (at KHSV). KHSV fog formation is a bit more uncertain, as some models forecast winds to remain at 4 or 5 knots through much of the night. These winds likely will become lighter briefly between 04Z and 07Z as well though. Winds remain from the south tomorrow, but increase around 08Z to around 5 knots or higher. This should dissipate any fog formation into the daybreak hours. Winds really increase after 12Z with sustained winds around 15 knots with gusts to around 20 knots. Some higher gusts are possible after 18Z, between 25 and 30 knots. Cigs around 5000 feet develop between 18Z and 21Z at both terminals. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...KTW SHORT TERM...12 LONG TERM...BCC AVIATION...KTW For more information please visit our website at
Area Forecast Discussion
National Weather Service North Platte NE
552 PM CST Sat Nov 24 2018 .SHORT TERM...(This evening through Sunday) Issued at 300 PM CST Sat Nov 24 2018 The RAP and HRRR models are tracking the h700mb low slightly west of the mainstream model consensus. More of western and ncntl Nebraska will be favored for snowfall and a slight increase in amounts (about an inch or so) is in the forecast. Satellite and sfc obs indicate productive deformation zone across WY this afternoon which will shift into Nebraska late this afternoon and tonight. The new forecast shows a few areas of Sheridan and western Cherry county could receive around 6 inches of snow. About 1 to 2 hours of heavy snow and very low visibility is expected as the arctic front moves south through central and srn Nebraska tonight. This heavy snow should be accompanied by strong wind gusts to 45 mph. The RAP shows the h700mb low moving at 40 mph which is very fast. Both the RAP and HRRR models show very strong radar returns in their reflectivity products which suggests convective snowfall rates of 1 inch per hour or greater will develop for an hour or two followed by lighter snowfall rates for a few hours. Given the 25 to 35 mph winds and gusts to around 45 or 50 mph predicted by the HRRR and RAP models, a period of blizzard conditions will develop tonight which should be brief once the snow diminishes in intensity. It would be the perfect opportunity for the NWS`s new snow squall warning product but national guidance on the product has not been released so instead, look for significant weather advisories or special weather statements on the progress of this potentially dangerous weather event. The snow and strong winds will exit srn Nebraska by sunrise Sunday with a few hours of gusty winds in the morning. Gradual clearing is expected throughout the day with highs in the 20s to lower 30s. .LONG TERM...(Sunday night through Saturday) Issued at 300 PM CST Sat Nov 24 2018 Two significant weather systems have been identified in the extended forecast. The first is Wednesday with a second Friday into Saturday. The system Wednesday is just a weak disturbance moving through in northwest flow and will mainly impact areas east of along and east of highway 83. Arctic high pressure will be centered over the Midwest with the cold air backed into eastern and part of ncntl Nebraska. The ECM and GFS are reasonably good agreement for a chance of freezing rain and snow. The model p-type in both models indicate some chance for freezing rain/drizzle. Very light QPF is forecast in both models and the GFS ensemble (less than 1/10 of an inch) as the better focus aloft will farther east in the Missouri River basin. The weather system Friday into Saturday could be more problematic. In fact, the system appears to resemble the ongoing storm according to the GFS ensemble with the upper support moving through the nrn Rockies and dipping into Nebraska. This will also be a rain to snow event and the model consensus favors eastern Nebraska for the best QPF as a fairly strong surge of moisture develops from the south. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 552 PM CST Sat Nov 24 2018 For KLBF...Rain is expected to arrive within the next hour before quickly changing over to a rain/snow mix. All snow is expected by 05Z. Blowing snow is a concern for tonight and into Sunday morning as northwest winds gust up to 35 knots. Snow ends by mid morning Sunday with VFR conditions returning by late afternoon. For KVTN...Snow will continue through Sunday morning. Northwest winds will increase to near 35 knots during the overnight hours causing blowing snow and reductions in visibilities. Snow is anticipated to end by 10Z to 12Z with VFR conditions returning by mid afternoon. && .LBF WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 9 AM CST /8 AM MST/ Sunday for NEZ006>009-022>025-035-036-056>058. Winter Weather Advisory from 9 PM this evening to noon CST Sunday for NEZ038-059-070-071. Winter Weather Advisory until 9 AM CST /8 AM MST/ Sunday for NEZ004-005-094. Winter Weather Advisory until noon CST /11 AM MST/ Sunday for NEZ010-026>029-037-069. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Kulik
Area Forecast Discussion
National Weather Service New York NY
933 PM EST Sat Nov 24 2018 .SYNOPSIS... A Deepening area of low pressure moves just south of Long Island tonight, with brief high pressure building in behind Sunday. Another storm system passes Monday. Deep low pressure remains northeast of the area resulting in cold northwest winds through much of the week. High pressure builds by late week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... No changes at this time, the forecast appears on track. Monitoring axis of heaviest rain, and observing 1/2-3/4 rainfall rates per hour in some of the heavier bands SW of the region. HRRR progs this heavier rain to remain south. Sfc low pressure and apparent pressure falls backed by latest model guidance suggest a slight shift to the south per previous guidance. Weak instability may settle just south of LI as well, so cut back thunder chances from the south shore of LI, southward over the ocean waters. Still looks like moderate to heavy rain will impact the area through 3-4 am. At this time, do not foresee widespread flash flooding per guidance and observed rainfall rates. However, urban and poor drainage flooding is likely, and locally heavier amounts of 2 inches or more is still possible. Rainfall quickly decreases in coverage into morning as subsidence increases behind the departing system. Temperatures remain steady or rise a few degrees, with warmest temps across eastern LI where E/SE winds ahead of the low bring in warmer air. NW locations likely remain in the mid to upper 30s. Plain rain is expected, with any freezing rain remaining to the north of the CWA. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Dry conditions develop for Sunday into much of Sunday night as brief upper riding and an attendant surface high move through. As the surface high will be centered more to the south (e.g. will not be of arctic origin...) the air mass will remain mild and closer to climatological normals, aided slightly in weak downslope flow into the metros. The high then shifts offshore overnight, giving way to weak warm advection ahead of the next approaching frontal system. It is possible that light drizzle develops by daybreak Sunday night as moisture increases beneath a lingering low level inversion, however precipitation is more likely into Monday. Low temperatures will be close to normal for time of year. && .LONG TERM /MONDAY THROUGH SATURDAY/... Upper ridge axis passes Monday, followed by an upper level low with embedded shortwaves pivoting around the base of the low as it slowly heads east. The upper low passes well to the northeast late in the week, and amount of ridging behind the low differs due to model differences in downstream trough out west. Overall, the upcoming week will be characterized by colder than normal conditions once the Monday storm system passes. Gusty cold NW flow prevails Tuesday through Thursday, with a secondary sfc front crossing the area Thursday. By Friday and Saturday, high pressure slowly builds which will result in lightening winds but still cold temps. For the Tue-Sat timeframe, temps should average at least 5 degrees below normal. The weather is dry Tue-Sat for the most part, outside of any rain/ snow showers mid week associated with the upper low. For Monday, a period of moderate to heavy rain looks to be confined to Monday afternoon into the evening. The system is progressive, so a prolonged steady rain is not anticipated. On average around 1/2 of rain is expected with this system as it moves through. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Low pressure will track northeast from the Delmarva Peninsula this evening to south of Nova Scotia by Sunday evening. Becoming IFR or throughout by around midnight as heavy rain overspreads the area from SW to NE. Conditions should improve to VFR by mid Sunday morning at all but KSWF and KGON where MVFR conditions should linger will into Sunday afternoon, before becoming VFR late. Most likely any thunder stays to the south of Long Island, however cannot completely rule out overnight at KJFK and KISP. LLWS mainly at NYC/Long Island/CT terminals into the overnight hours. Winds back to the NE-N and increase to 15-20KT overnight (except remain light and variable at KSWF). Winds become NW throughout by mid Sunday morning at around 10-15KT. City/Long Island/W CT terminals could see gusts around 20KT Sunday afternoon. .OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY... .Sunday night...VFR, then becoming IFR late. .Monday-Monday evening...IFR or lower likely in Rain. LLWS possible. SE winds G15-20KT possible Monday, LLWS possible eastern terminals Monday evening. .Late Monday night-Tuesday night...VFR. NW winds G20-30kt Late Monday night/Tuesday morning. W winds G15-20KT possible Tuesday afternoon/night. .Wednesday-Thursday...VFR. Possible exception Wednesday of isolated-scattered snow showers producing localized MVFR conditions. W-NW winds G15-25kt possible. && .MARINE... No changes at this time. The forecast appears on track. A strong low pressure system is expected to move over the waters overnight, with a strengthening pressure gradient leading to E/SE gales on the eastern ocean/Long Island Sound and bays late tonight. Additionally, NW flow may briefly remain strong during the morning on the eastern ocean waters as low pressure departs. Otherwise, seas on the ocean waters will gradually subside but remain at or near SCA-levels into Sunday and Sunday night as weaker flow develops across the area in response to high pressure. By Monday, E/SE winds increase ahead of a front and area of low pressure. The low passes over the waters by evening, then deepens as it tracks to the northeast. Winds shift around to the NW, and gusty conditions will prevail through the mid week period. As such, SCA conditions are likely for quite some time early to mid week across the waters. Gale force wind gusts are possible from time to time. && .HYDROLOGY... A quick moving low pressure system will produce around 1-2 inches of rain across the area, with locally higher amounts possible in any heavier rain. At this time, do not foresee widespread flash flooding per guidance and observed rainfall rates upstream. However, urban and poor drainage flooding is likely particularly near any leaf clogged drains. Additionally, there may be localized flooding along flashy small rivers, streams and creeks in northeastern NJ. Another fast moving system will bring the potential for 1/2 inch of rain Monday into Monday night. Do not expect widespread hydrologic impacts with this system. && .TIDES/COASTAL FLOODING... Astronomical tides are much higher during the day around high tide, around a 1 ft difference. However, with low pressure expected to pass south of Long Island this evening, feel there may be enough surge for vulnerable locations to approach if not exceed minor coastal flooding benchmarks tonight as east winds increase around the time of high tide. The greatest threat is across the South Shore Bays of Long Island, and western LI Sound, but do have some concerns for Peconic/Gardiners Bays of eastern LI and the lower NY Harbor due to easterly fetch/tidal piling around high tide. Fresh water rainfall coinciding with high tide will not help either. For Sunday morning, winds do shift around to the N/NW as the storm system moves east, but residual surge may result in localized flooding once again as astronomical tides are much higher as previously noted. As such, will post a coastal flood statement for much of the area except SE CT. This statement will cover the next two tide cycles, tonight and Sunday morning/early afternoon. Do not anticipate any issues for Sunday night`s high tide. Then attention turns to Monday. At this time, the high tide cycle looks vulnerable for widespread minor to locally moderate coastal flooding. Too far for any coastal flood products attm, but this tide cycle will need to be watched closely as E/SE winds increase ahead of another area of low pressure that develops along a frontal boundary. && .EQUIPMENT... NYC Central Park winds are out of service until further notice. Loss of data is due to a severed cable. Parts are on order. NYC NOAA Weather Radio Station KWO35 (162.55 MHz) will remain off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 1 PM EST Sunday for ANZ335-338-345. Gale Warning until 7 AM EST Sunday for ANZ330-340. Small Craft Advisory until 7 PM EST Sunday for ANZ353-355. Gale Warning until 1 PM EST Sunday for ANZ350. && $$ SYNOPSIS...MD/PW NEAR TERM...PM/PW/MD SHORT TERM...MD LONG TERM...PW AVIATION...Maloit MARINE...PM/PW/MD HYDROLOGY...MD/PW TIDES/COASTAL FLOODING... EQUIPMENT...
Area Forecast Discussion
National Weather Service Pueblo CO
748 PM MST Sat Nov 24 2018 .UPDATE... Issued at 749 PM MST Sat Nov 24 2018 Updated/refreshed grids zones to increase pops over the southeastern Colorado plains this evening. Also, recently allowed the high wind warning for the southern Sangre de Cristo Mountains to expire. && .SHORT TERM...(This evening through Sunday) Issued at 353 PM MST Sat Nov 24 2018 ...Wind driven snow will continue along the Continental Divide with damaging winds expected across the plains through tonight and some wind driven snow on the Palmer Divide... Forecast has been very fluid today with models trending stronger and farther west with the storm track with each run. Upper low now closes off across northeast CO this evening and tracks into western KS by 09z. This has resulted in a slightly delayed front (though only by an hour or so) but also a stronger surge behind the front as upper low intensifies and drops southeastward. As of 22z...front has passed through COS and should arrive along the Arkansas river around 4 PM...and will pass through the remainder of the southeast plains by 6 PM. Getting gusts to around 60 mph behind the front at AFA and LIC...and expect similar gusts to spread across southeast Colorado immediately behind the front. Current high wind highlights look on target. High res models are showing another surge of even stronger winds will spread across the southeast plains after 10 PM as the system deepens across eastern CO. Gusts with this second surge could approach 70 mph across the plains given the tight surface pressure gradient. Strong cross winds on east west oriented roadways and the potential for property damage will be greatest after 10 PM into the early morning hours. With the system wrapping up farther west than previously anticipated...models are now suggesting a window of wind driven snow will be likely for the Palmer Divide. Storm will be brief, hitting hardest in the 03z to 09z window and producing a couple inches of snow across northern El Paso County. If snow were heavier and duration longer, this would be a blizzard event. But given the lighter snow amounts and shorter duration, think the main impact will be from wind and the potential for wind damage rather than the blowing snow. So, have hoisted a winter weather advisory for now along to highlight the potential for brief impacts to visibility given the blowing snow potential. Later shifts will need to monitor high res model trends closely. Have also added some pops and snow to the northern slopes of the Raton Ridge tonight based on latest HRRR runs...though accumulations look much lighter so no winter weather highlights look necessary at this point. Can`t stress enough that this system has been rapidly evolving and further changes to the forecast may be necessary as this event unfolds. Snow and blowing snow will also continue along the Continental Divide this evening. Current warnings and advisories for the central mountains look on target. Have included the La Garita mountains in the advisory given latest radar and trends in the HRRR model run. This area could see total accumulations in the 2 to 6 inch range. The remainder of the mountains should see accumulations more in the 1 to 3 inch range. Winds will taper down early Sunday morning and forecast area will dry out. Temperatures will be quite a bit cooler than today...though with gusty north winds through the morning should still manage to climb into the 40s for the plains. Mountains will see temperatures in the 20s and 30s with teens above timberline. -KT .LONG TERM...(Sunday night through Saturday) Issued at 353 PM MST Sat Nov 24 2018 Hello Southern Colorado! First time, long time. Looking forward to many years of service to the region for all your weather needs. The mid-level pattern starts off rather quiet across the region with shortwave ridging and zonal-ish flow in place. By the end of the current long term period we could see another shortwave trough traverse near the region but as of now the timing and strength of the system is still very uncertain. As mentioned above, the first part of the long term is rather quiet with ridging in place helping to dry us out. Some of the valleys across the west look to have a pretty good shot at nearly perfect radiational cooling so have dropped overnight lows both Sunday and Monday nights at least 8-10 degrees edging closer to the MET guidance. Decent amount of dry air in place much of the week will allow for crisp cold nights rebounding nearly 30-40 degrees for daytime highs outside of the higher terrain ; several degrees above average for late November. Those larger diurnal ranges are just fantastic. A very weak shortwave trough of low pressure may provide enough lift, with some moisture in place, to generate a few high terrain snow showers on Wednesday, but at this point it`s not much to write home about. The next potential, larger, system is still a ways away, try saying that 10 times fast. Still lots of uncertainty with how quick and deep the system moves into the region. The ensemble trends with the mid-levels has been variable, to say the least, the past several runs. The EPS has been closing off the wave as of late while the GEFS and GEPS keep the wave much weaker and quicker moving off towards the east. At this time, the model spread allows us only so much confidence to keep PoPs in the chance/scattered range with snow in the west and rain across the Plains. Again it is way too early to finetune this system but the general trend has been a quiet work week with a weekend trough/low. Does this trend continue into December? && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 353 PM MST Sat Nov 24 2018 A strong cold front will bring a wind shift from the north with gusts to around 50 kts for KCOS and KPUB through the afternoon. Showers along the Palmer Divide may come close to KCOS bringing some brief VFR to high end MVFR cigs...but largely look to stay north of the area. Any snowfall would be brief and light with amounts under an inch. KPUB will likely remain dry. Another surge of strong winds will spread across the plains after 04z and could see gusts up to 55 kts through the early morning hours. Winds will decrease Sunday morning. KALS will remain breezy from the west with gusts to around 40 kts through the evening. Winds will shift around from the north and gradually decrease overnight. Some brief VFR cigs will be possible during the overnight hours. Lighter winds can be expected for Sunday. Mountains will remain obscured along the Continental Divide overnight with SN and BLSN. The southeast mountains will see periodic mtn obscurations through midnight along the crest of the Sangres, and Pikes Peak. Winds will gust to around 60 kts at times but will diminish towards early Sunday morning. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 2 AM MST Sunday for COZ083>089-093-094. High Wind Warning until 5 AM MST Sunday for COZ095>099. Winter Weather Advisory until 5 AM MST Sunday for COZ059-061. Winter Storm Warning until 5 AM MST Sunday for COZ058-060. Winter Weather Advisory until 11 PM MST this evening for COZ064- 066. Winter Weather Advisory until 5 AM MST Sunday for COZ084. && $$