Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/09/20

Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
553 PM CST Sun Nov 8 2020 .UPDATE... Seeing just enough H7 moisture influx to generate showers across the area ahead of weak S/WV. Might be just enough instability to generate an isolated TSTM as well. Increased POPs this evening to 20-25% in central areas where best chances for measurable rain are expected. Could make an argument for higher increase based on HRRR and may need to make additional updates. && .AVIATION... SHRA and possibly a TSTM will impact central portions of the Panhandle as a disturbance moves across the area. AMA has best chance of seeing this activity as it lies in the middle of the narrow moisture/instability axis. This activity will be somewhat light and high based. Minimal impacts to CIGs is expected and cloud bases should remain above MVFR levels, however did include a TEMPO with minimal impacts in AMA TAF during evening hours for TSTMs. Some MVFR visibility is possible in stronger cells, but chc of this happening at terminal is low. MVFR stratus CIGs are expected to mainly stay east of AMA to GUY for the early morning hours on Monday and VFR conditions will develop across entire region by late morning. && .PREV DISCUSSION... /Issued 234 PM CST Sun Nov 8 2020/ SHORT TERM...Tonight through Monday Night... Strong south to southwest flow will continue today and tomorrow over the Panhandles. Breezy to windy conditions will continue through the evening and into Monday as the system stays stalled over the Four Corners area. Dewpoints have been kicking up under this south southeast surface flow across the central and eastern Panhandles so much that a Pseudo-dryline is expected to setup. Although it doesn`t appear that we will see much of any showers or storms, the is about a 10 percent chance that something could pop this afternoon and evening. A pacific front is expected to move through mid afternoon tomorrow with low RH values and breezy westerly winds. Thunderstorms out ahead of the front will be possible, but it looks like the front will be through to early and the storm development is expected east of the Panhandles. A cold front is then progged to enter the Panhandles from the north tomorrow night, bringing near freezing temperatures to the southern Panhandles and below freezing temperatures to the northern Panhandles by Tuesday morning. Cold front is expected to be dry. It looks like the winds will relax by Tuesday morning, and therefore the wind chill should not be too bad. Weber FIRE WEATHER...Today and Monday... RFTI`s in the 2-4 range all driven by wind will continue today across the western Panhandles. While ERC`s are in the 60+ percentile in the northwest, the rest of the western Panhandles is below the 50th percentile, and therefore will only be elevated. Any fires that occur on Monday and continue to burn into the late evening, will be subject to a north wind shift with the cold front. Otherwise winds out of the west 25-30 mph with some gusts up to 40 mph possible. Weber LONG TERM (Tuesday through Saturday)... Overall, the long term is pretty quiet outside of a small chance for rain and perhaps some thunderstorms Friday/Friday night. Otherwise, highs in the 50s and 60s are expected with plenty of sunshine through next weekend. Could see some clouds Friday with those rain chances, and this day also looks to be our breeziest day of the long term with sustained speeds around 15-25 mph. In the upper levels, a Rex block is evident off the east coast/Gulf of Mexico, while broad long wave troughing is evident over much of the CONUS. The Rex block will slow the progression of the trough eastward, with nearly all the embedded energy within this trough staying north of the forecast area. So, not expecting much if anything in the form of precipitation for the Panhandles until we transition out of this pattern. Looks like the blocking pattern breaks down Thursday and we begin to transition to a more zonal flow over the Panhandles, and by Friday our first shortwave trough looks to pass over the forecast area. Unfortunately for us, the available moisture looks better east and south of our area, so this only puts us in about a 20 percent chance for rain across the eastern Texas Panhandle. Our CAPE values are not looking as good as they did in the previous forecast. That said, with a few hundred J/kg of MUCAPE we could get a thunderstorm or two to form if any showers materialize. Another feature to watch will be an upper level jet streak (300mb) around 110-125 knots which could provide an additional source for lift. All in all, our chances for rainfall appear slim at this time. Guerrero && .AMA Watches/Warnings/Advisories... TX...None. OK...Red Flag Warning until 6 PM CST this evening for the following zones: Cimarron. && $$ 88/88
Area Forecast Discussion
National Weather Service Cheyenne WY
710 PM MST Sun Nov 8 2020 .UPDATE... Issued at 702 PM MST Sun Nov 8 2020 ...Light to occasionally moderate snow tonight for the eastern plains... Current forecast for tonight and early Monday looks on track, with KCYS radar loop showing some midlevel snowfall developing along and just east of the I-25 corridor. Expect this trend to continue over the next few hours as the upper level trough near the four corners region slides eastward. A strengthening upper level 135 knot jet will be located across the eastern plains tonight, with impressive difluence aloft shown through noon Monday. For now, kept the 1 to 2 inches of snow along and east of the I-25 corridor. However, we expect some locations to see as much as 3-5 inches in the heavier bands of snow. Low confidence in the placement of these heavier snow bands, so will hold off on Winter Weather Advisories for now. Did note some really low dewpoint temperatures at the surface this evening, so the snow may take a while to reach the ground. && .SHORT TERM...(Tonight - Tuesday) Issued at 232 PM MST Sun Nov 8 2020 Snow chances are expected to increase significantly this evening & overnight as a deep upper-level low continues to spin over much of the western CONUS. A more substantial piece of mid-level energy is expected to eject northeast from the 4 Corners region after around 06z, impacting the high plains of southeast WY and western NE thru 18z Monday. There is growing concern that a band of heavy snow may develop from near Cheyenne northeastward through Chadron overnight tonight through early Monday. This area will be in the favored LFQ of an intense/140 knot H25 jet, well-placed beneath persistent low level frontogenesis. A broad area of negative saturated EPVS would indicate the presence of instability and resultant locally heavier snowfall rates. Ensemble plumes do not support significant amounts of snow, but trends in the HRRR have been toward heavier, and more widespread precipitation overnight. Confidence in a swath of snow- fall amounts of 1-2 inches (locally 2+) is growing, so this is the main change to the inherited forecast for tonight. Advisories will hopefully not be needed, but this will be something to watch. Snow showers will persist through much of the day on Monday w/ the potential for light accumulations mainly west of the Laramie Range and in the mountains. In general, expect an inch or two in the low elevations with 3-6 inches in the mountains through late afternoon on Monday. The focus will shift toward high winds Monday night and Tuesday as another short wave sweeps east across the northern high plains. The resulting pressure falls will increase 700/850 mb CAG- CPR gradients into the 60-70 meter range along with 55-65 knots of 700-800 mb flow over the wind prone areas. We have gone ahead with a High Wind Watch for 03z Tuesday through 06z Wednesday. .LONG TERM...(Wednesday - Sunday) Issued at 257 AM MST Sun Nov 8 2020 Generally cool to mild conditions across the CWA this period with several shortwaves passing across in a progressive pattern. One looks to scoot across late Weds with the next ones late Friday and late Saturday. Not much in the way of pcpn with these outside of the higher mtns where periods of snow showers are expected. Temperatures fairly close to seasonal averages along with periods of gusty winds with the passing of these systems. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 430 PM MST Sun Nov 8 2020 VFR conditions expected to persist for next 6 hours as a mid-level energy coupled with frontogenic forcing will contribute to an overnight increase in snow and MVFR to IFR conditions for majority of terminals. Have trended TAFs a bit to LAMP guidance coupled with lower visibility and CIGS in periods of expected snowfall. CIGS will remain low through at least 18z with expectation that forcing aloft will keep conditions low through much of the daylight hours Monday. && .FIRE WEATHER... Issued at 257 AM MST Sun Nov 8 2020 Elevated fire weather conditions linger yet another day across the western Nebraska Panhandle`s I-80 corridor with only a short window of opportunity to receive light precipitation this morning as a strong cold front passes through the region. This front is currently situated just west of the Laramie Range, and has been associated with strong and gusty winds. These winds will continue to effect the region with High Wind Warnings in place for the wind-prone areas of southeast Wyoming and most of the Nebraska Panhandle. Quick, light shots of moisture will remain for most of the week, though the mountains look to receive the most precipitation. The windy pattern will remain as well. Minimum humidities drop into the 20s again at the end of the week. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...High Wind Watch from Monday evening through Tuesday evening for WYZ106-110-116-117. NE...None. && $$ UPDATE...TJT SHORT TERM...CLH LONG TERM...RE AVIATION...WM FIRE WEATHER...AB
Area Forecast Discussion
National Weather Service Quad Cities IA IL
256 PM CST Sun Nov 8 2020 .SYNOPSIS... Issued at 130 PM CST Sun Nov 8 2020 Beautiful near-record warm conditions continue across the CWA today. Temperatures are once again already in the 70s as of 1 pm area wide. Dewpoints have climbed into the upper 50s/low 60s and with temperatures nearing the convective temp, scattered Cu has started to develop. Gusty south winds between 20-25 mph have also been observed. && .SHORT TERM...(This Evening through Monday) ISSUED AT 230 PM CST Sun Nov 8 2020 Forecast focus in the near term is on temperature and cloud trends. This Evening-Tonight...high temperatures should fall just shy of record highs for the date. Models have struggled today in terms of cloud cover and temperatures, with bulk of guidance showing more widespread clouds and thus lower temps. The 15z HRRR was the first model to have a good handle on temps and used as a guide with highs today. Winds will subside after sunset this evening, but remain above 10kts. Stronger WAA aloft, higher dewpoints, and more cloud cover, will keep temperatures in the low 60s overnight. The 12z HRRR ensemble has higher probabilities of cloud cover west of a FFL to DBQ line tonight, which may see warmer readings than further east. Record warm lows will be possible for Nov 9th and are listed in the climate section below. Monday...another pleasant early November day is forecast with near record temperatures and breezy south winds. A great day for any activities outside. Pressure gradient will increase between a surface low moving east over Nebraska and large high over the eastern CONUS bringing strong southerly winds, gusting between 25-35 mph in the afternoon. Cloud trends and depth of mixing will be the main factors as to how warm we get. Went with the 75th percentile of all guidance for highs and still may be too cold. Current forecast has temperatures within 1-2 degrees from record highs. All 12z models and most hi-res solutions have now backed off on developing light showers ahead of cold front during the day and I have removed slight chances from forecast after collaboration with neighboring offices. The better moisture and forcing signal remain to our west until Monday night and Tuesday. .LONG TERM...(Monday Night through Sunday) ISSUED AT 230 PM CST Sun Nov 8 2020 Key Messages: 1) Strong cold front Tuesday with rain, thunder and wind 2) Colder /near normal/ temperatures mid to late week. Forecast details: Monday night Breezy and continued unseasonably mild, with near record/record warm lows for much of the area well into the 50s to lower 60s. The exception potentially being some of our far northwest counties, or areas roughly west of a Manchester to Marengo line where a cold front could begin to make inroads late at night settling temperatures into the 40s post-frontal. A lot of uncertainty though to the progression of the front, as a wave of low pressure is suggested to develop associated with an approaching vigorous mid level shortwave. This will look to assist increasing rain chances mainly west of the Mississippi River. Tuesday and Tuesday night Lifting mid level wave and attendant surface low rippling along the cold front will provide more persistent and widespread rain across our west/northwest areas on Tuesday. PWATs are shown to increase to around 1.3 inches supportive of swaths of 1-2 inch rain potential. The precipitation is likely to transition to more linear band(s) of showers and embedded storms along and especially east of the Mississippi River ahead of mid level dry slot and cold front. These will bring brief bouts of heavy rain with overall amounts a bit lower and generally 0.25 to 0.75 inch. Shear profiles remain fairly impressive for nearly mid November, but instability is rather weak. Nonetheless, will have to continue to monitor the late morning until mid afternoon period ahead of dry slot for an isolated severe threat /mainly wind/ with SBCAPEs progged 300-600 j/kg. Especially monitoring for any steepening of lapse rates and potential pockets of solar insolation which could foster increased threat of mixing down severe gusts to surface. In addition, will have to keep a close eye on extent of the low level frontal circulation, which could aid in backing low level winds resulting in some brief tornado potential as well pending extent of BL destabilization. Dry slot should rapidly shut down precipitation in the afternoon from SW to NE. Winds ahead of the cold front on Tuesday could be near advisory criteria at times along/east of the Mississippi River near nose of strong low level jet. Most areas are expected to see highs occur in the morning through midday before falling after the frontal passage. Brisk west winds are possible for a time Tuesday evening post-frontal in the wake of the departing low. These winds will continue to usher in colder air, with lows falling into the upper 20s to lower 30s. Precipitation looks to be pulling away and any wrap-around staying mainly north before colder air works in to create any change-over concerns. Wednesday through Friday Colder /more seasonable/ temperatures look to persist through late week. Continuing to see some signal in the late Thursday into early Friday timeframe for a light mixed precipitation event. Confidence however is very low, as models struggling namely with the placement/magnitude of surface high pressure. Aloft, there`s good agreement on a trough migrating across the Upper Midwest. Questions revolve more around track of vort max and main upper forcing, and location of the surface high pressure and attendant low level reservoir of dry air. As mentioned, should we see any precipitation it is expected to be light. Next weekend Signal continues to trend toward potentially another active period sometime of the weekend, as additional Pacific energy shifts eastward into the central CONUS. Considerable differences exist in the medium range guidance in the track/timing of the energy although starting to see a north/west trend, and if this continues would expect another rain event. Strong jet and baroclinicity would support potentially a fairly dynamic system, with possibly a severe storm and wintry side so will be needing to watch this closely to see how it evolves. && .AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon) ISSUED AT 1117 AM CST Sun Nov 8 2020 VFR conditions to continue through this evening with gusty south winds dissipating after sunset. With winds likely remaining above 10kts through the overnight hours, kept LLWS mention out of TAFs for now. Clouds are expected to increase in eastern IA overnight, with MVFR cigs possible. Southerly winds will again increase near the end of TAF period, ahead of approaching system from the west. && .CLIMATE... ISSUED AT 230 PM CST Sun Nov 8 2020 Record Warm Lows for November 9... Moline.........58 in 1931 Dubuque........53 in 1999 Record Highs for November 9... Moline.........77 in 1999 Cedar Rapids...76 in 1999 Dubuque........74 in 1999 Burlington.....76 in 1999 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...Gross SHORT TERM...Gross LONG TERM...McClure AVIATION...Gross CLIMATE...Gross
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
952 PM EST Sun Nov 8 2020 .SYNOPSIS... Warm and dry high pressure will become centered off the New Jersey coast on Monday and remain there through Tuesday. Meanwhile, a cold front will slowly approach from the west, while Tropical Cyclone Eta tracks near southern Florida and into the Gulf of Mexico. The front will slowly cross the forecast area Wednesday through early Friday, keeping the weather unsettled. && .NEAR TERM /THROUGH MONDAY/... At 940 pm EST: Another very slight uptick in overnight mins was warranted on the latest update, with obs running just a bit warmer than forecast trends, and clouds poised to thicken and lower beneath the subsidence inversion in the moist easterly flow. The near-term models are very conservative on overnight precipitation, but a few weak radar returns are already indicated in a few spots in the mountains, and the RAP features slightly better sfc to 850 mb moisture and upslope flow into the eastern escarpment from 06Z to 09Z. Isolated light rain showers will be featured in the upslope areas through the early morning hours. Otherwise, the overall synoptic pattern will not change much over the near term period, with vertically stacked high pressure slowly transitioning farther SE off the mid-Atl coast. Another round of improving moisture flux in the onshore flow will permit low end isolated to scattered PoPs to rebound once again late Monday in the eastern escarpment upslope areas. Any precipitation amounts will be quite light. Max temps Mon will be similar to Sunday, or perhaps a touch less in cloudier areas, with readings in the low to mid 70s east of the mtns and upper 60s in the mtn valleys. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 155 pm Sunday: A high amplitude/non-progressive pattern will persist through the short term, with deep anticyclone expected to remain centered off the southeast coast, and broad/strong trough over the West. Resultant deep SE flow will allow tropical moisture plume/atmospheric river north and east of T.C. Eta to begin streaming over the forecast area Tuesday and remain through the end of the period. Pops will address increasingly moist SE upslope flow with a gradual uptick and expansion from Tue morning through Tue night, with 70-90 probabilities advertised across the entire area by sunrise Wed. By and large, precip amounts should be manageable from a hydrology perspective through at least Wed morning, as lifting mechanism will generally be limited to upslope effects, although at least locally heavy rainfall will be possible within a narrow axis along the southern Blue Ridge escarpment. This may change later Wed into Wed night, as frontal zone associated with the first in a series of short wave troughs lifting out of the Desert Southwest moves into the region. This will act as an additional source of focused lift of a tropical air mass. That being the case, the most likely time for a localized excessive rainfall threat will be late Wed into Wed night, with additional heavy rainfall potential coming from an increasing risk of thunderstorms, as short term guidance is in good agreement in advecting at least modest levels of instability Wed afternoon. By sunrise Thursday, storm total amounts of 1.5 to 2.5 inches are expected to be widespread across the area, with higher amounts quite likely along the southern Blue Ridge as well as other areas of training tropical showers. Max temps will remain a few degrees above climo, and min temps well above normal, in fact jeopardizing maximum low temp records, esp Tue night and Wed night. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 220 pm Sunday: Confidence remains below normal in the medium range, although the situation is gradually coming into better focus for next weekend. Highly amplified pattern will persist through the period, albeit with the western Atlantic anticyclone expected to steadily weaken as a series of short wave troughs ejecting from the western Conus result in increasing occurrence of height falls across the East. In general, global models agree in allowing drier air to build into the area in the wake of the cold front late in the week, although at least small pops are retained into the weekend in light of increasing uncertainty. Of course, the elephant in the room is the eventual fate of TC Eta, and guidance generally continues to exhibit very little consensus and poor run-to-run consistency in this realm, but we will certainly not be out of the woods in terms of another round of heavy rainfall late in the week, especially as another frontal zone appears likely to impact the area in the day 6/7 time frame. Temps will generally remain above climo normal, but generally returning closer to normal levels by the weekend. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... At KCLT and elsewhere: Increasing low-level moisture advection from the east overnight will combine with a persistent inversion in profiles around 5 kft feet to allow cigs to thicken and lower through the nighttime hours. With slightly better mixing forecast than on earlier Sunday model runs, bases could be a tad higher overnight, with mainly MVFR for a good portion of the nighttime hours and the daytime hours on Monday, but with a 4 to 6 hour period of IFR cigs possible around daybreak at all sites. The main exception could be KAND, where the easterly flow moisture may not pool as quickly and IFR could be avoided. Otherwise, expect gradually increasing NE flow, SE at KAVL, with low end gusts with mixing onset on Monday. A return to VFR cigs is likely at most locations through the afternoon hours, and any showers worth mentioning will hold off until Monday night at KCLT. Outlook: Warm and moist flow at low-levels off the Atlantic will continue to produce ceiling restrictions Monday night through Friday, with the deepest moisture likely on Wednesday. Periods of MVFR to IFR cigs can be expected, especially once a slow moving front moves in from the west and greatly increases the chances of rain mid week. Confidence Table... 03-09Z 09-15Z 15-21Z 21-00Z KCLT High 100% High 86% High 88% High 84% KGSP High 100% High 88% High 86% Med 77% KAVL Med 71% Med 68% High 80% High 86% KHKY High 93% Med 75% Med 76% High 82% KGMU High 96% High 81% High 86% Med 77% KAND High 98% High 88% High 88% Med 75% The percentage reflects the number of guidance members agreeing with the scheduled TAF issuance flight rule category. Complete hourly experimental aviation forecast consistency tables are available at the following link: && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...HG/SBK SHORT TERM...JDL LONG TERM...JDL AVIATION...HG