Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/14/19


Area Forecast Discussion
National Weather Service Bismarck ND
1012 PM CDT Fri Sep 13 2019 .UPDATE... Issued at 945 PM CDT Fri Sep 13 2019 Showers are trying to hold on over eastern Montana as they approach the border. We did adjust pops modestly based on a blend of Previous forecast, HRRR and HREF. This cut back a litte on pops, especially south, but overall only minimal changes. Also adjusted sky cover a little based on latest Satellite and short term guidance. UPDATE Issued at 622 PM CDT Fri Sep 13 2019 We bumped up pops a bit late evening into the overnight hours over western ND. Showers and a few thunderstorms pushing across north central ND at this time ahead of a shortwave trough. Short term models bring this activity into northwest ND around midnight and track it across the CWA through around 16 UTC Saturday. Best chances remain across the northwest and north central, with chances tapering the farther south you go into southwest and south central ND. Kept a mention of isolated thunder through around 11 UTC. && .SHORT TERM...(This evening through Saturday) Issued at 225 PM CDT Fri Sep 13 2019 This afternoon, North Dakota sits between a stacked low pressure system spinning over southwest Ontario and an upper level ridge extending from central Saskatchewan through eastern Montana. 18Z surface analysis places a high pressure ridge over western North Dakota. Persistent cloud cover associated with the departing low is finally decreasing early this afternoon as ridging continues to build over the Northern Plains. This clearing will allow western North Dakota to see temperatures reach near 70 before diurnal heating ends for the day. Much of the rest of the area should see temperatures reach the 60s. Tonight into Saturday morning, a shortwave that is currently seen on water vapor imagery near Glacier National Park is forecast to track across the area. This will bring a chance of scattered showers and perhaps a thunderstorm to parts of western and north central North Dakota late tonight through mid morning Saturday. Behind the shortwave, the rest of Saturday is shaping up to be very pleasant, with clearing skies and highs in the 70s. .LONG TERM...(Saturday night through Friday) Issued at 225 PM CDT Fri Sep 13 2019 Warm and dry weather is expected Sunday into Tuesday as a strong upper level ridge builds over the central CONUS. Should see highs in the 80s for most areas these days. Monday looks to be warmest, when a few +90 degree readings may be possible. A strong upper level shortwave is forecast to move onto the Pacific Northwest early Monday and track towards the Northern Plains by Wednesday. This will bring chances for rain and cooler temperatures back to the region beginning Tuesday evening. Models begin to disagree on the synoptic pattern beyond mid week, but the general trend seems to suggest a southwest flow pattern for the Northern Plains, with longwave troughing over the western CONUS. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 945 PM CDT Fri Sep 13 2019 VFR conditions are forecast through the 00Z forecast period. Showers and isolated thunderstorms along a cold front will move into west ND around midnight and spread east across the forecast area through mid-late morning Saturday. At this time we limited shower activity to Williston, with a vcsh at KDIK and KMOT. Shower activity remains mostly north of KBIS and KJMS so too much uncertainty at this time. Kept the mention of thunder out of the forecast for the time being as thunderstorm activity currently over north central MT will likely wane as we move toward midnight. Still some possibility for thunder at KISN but too much uncertainty to include in the TAF at this time. Southerly surface flow this evening will shift westerly behind the cold front Saturday. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...Hollan LONG TERM...Hollan AVIATION...TWH
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
234 PM MDT Fri Sep 13 2019 .SYNOPSIS... Scattered showers and thunderstorms, some with localized torrential downpours, will continue to affect much of the region this afternoon and evening, with the focus slowly shifting into southwestern New Mexico. Thunderstorm chances will mainly be focused near and west of the Continental Divide this weekend, but will overspread the region again Monday and Tuesday as an upper level trough moves into the west coast, and winds aloft shift to the southwest again. Drier conditions will prevail mid-week. && .DISCUSSION... Surface obs show E to SE flow has pushed west of the Arizona line, with 50s dewpoints having overspread the area over the past few hours. Upper 50s to near 60 dewpoint remain in place generally east of the Continental Divide. RAP analysis suggests MLCAPE values of 800-1000 J/Kg over the NM Bootheel and eastward along the international border, with higher values up to 1500 J/Kg over Far West Texas and the Otero Mesa. CIN values are weak and mostly limited to the Gila Region where showers have so far been weaker. However, with the mid-level ridge axis over the area, we are lacking any focusing mechanism, and with an unstable and CIN-free sounding, we`re basically seeing relatively small multicell storms over both the higher terrain and the desert lowlands. Weak mid- level flow is also resulting in nearly stationary storms with a tendency to back-build. High-res models have had a tough time indicating any sort of consistent evolution of convection for this afternoon and evening, likely due to the lack of forcing and small horizontal scale of the showers/storms. Some earlier runs suggested thunderstorms would slowly increase in coverage and eventually converge on SW New Mexico this evening, roughly on the leading edge of the deeper low level moisture (mid/upper-50s dewpoints). Basically kept broad-brushed scattered PoPs in through the afternoon and evening, slightly favoring SW New Mexico tonight. Both the NAM and GFS have consistently developed a convectively- induced mid-level low over the northern Sierra Madres by Saturday morning, and carry this feature northwards along the western edge of the subtropical ridge, pulling the deepest subtropical moisture into far SW New Mexico and southern Arizona, while drier and slightly warmer air aloft tries to seep into areas east of the Rio Grande. We will likely still see a few isolated storms in the eastern lowlands tomorrow, but the better coverage of storms will be over the Gila and Bootheel Regions. This pattern looks to continue into Sunday, as the mid-level disturbance moves northwards towards the Four Corners, and a sharp upper level trough moves into the West Coast. This trough will cause mid-level winds to veer more to the southwest, spreading monsoonal moisture to the east Monday and Tuesday. The west coast trough looks to take a more northerly route, limiting wind shear and upper level forcing with the trough passage on Tuesday (diminishing the risk of isolated severe thunderstorms). Drier air aloft will push in from the west on Wednesday, diminishing the threat of precip through at least Thursday. && .AVIATION...Valid 14/00Z-15/00Z... P6SM FEW-SCT070-090 SCT-BKN200-250 through period. Expect scattered storms with VRB25G40KT 1-3SM TSRA BKN030-040 across area through 06Z then becoming more isolated through 18Z. Storms expected to increase in coverage again, mainly mountains and west of divide after 18Z. Winds east to southeast at 5-15KTS. && .FIRE WEATHER... Moisture has returned to the area with scattered showers and thunderstorms expected through this evening and continuing into early next week as a Pacific trough moves over the Rockies. The best precipitation chances after today will be focused in the mountains and west of the Rio Grande, but isolated storms will continue to affect the eastern lowlands. Temperatures will be near to slightly below normal for most of the period with minimum relative humidities remaining above 25-30 percent most days over the lowlands and 30-40 percent in the mountains. Winds through the weekend will be east to southeast at 5-15 mph, but gusty near thunderstorms. Vent rates through the weekend will range from fair to very good. && .PRELIMINARY POINT TEMPS/POPS... El Paso 68 87 67 87 / 30 20 10 10 Sierra Blanca 62 85 59 82 / 30 10 0 0 Las Cruces 65 85 61 84 / 40 20 20 20 Alamogordo 64 86 62 86 / 40 30 20 20 Cloudcroft 50 65 45 64 / 50 60 30 40 Truth or Consequences 64 84 63 84 / 50 30 30 30 Silver City 59 79 58 77 / 60 50 40 40 Deming 65 84 62 84 / 60 30 30 30 Lordsburg 65 87 62 83 / 50 40 40 40 West El Paso Metro 69 86 67 87 / 30 20 20 10 Dell City 65 88 62 87 / 30 10 0 0 Fort Hancock 69 89 67 89 / 20 10 0 0 Loma Linda 62 81 62 81 / 30 20 0 10 Fabens 68 88 67 87 / 20 10 10 10 Santa Teresa 67 85 64 85 / 30 20 20 10 White Sands HQ 66 84 65 85 / 40 20 20 20 Jornada Range 64 84 61 85 / 50 20 20 20 Hatch 65 84 61 85 / 50 30 30 20 Columbus 67 86 64 85 / 40 20 30 20 Orogrande 65 86 62 85 / 30 20 10 10 Mayhill 54 74 50 73 / 60 40 20 20 Mescalero 54 74 49 74 / 50 50 30 40 Timberon 53 72 48 72 / 50 40 10 20 Winston 54 78 50 77 / 50 50 40 40 Hillsboro 60 82 59 82 / 50 50 40 40 Spaceport 62 84 59 84 / 50 30 30 20 Lake Roberts 54 79 51 77 / 50 60 40 40 Hurley 60 80 57 79 / 50 40 40 40 Cliff 60 87 56 85 / 50 50 30 40 Mule Creek 61 85 59 79 / 50 60 40 50 Faywood 61 81 59 80 / 60 40 40 40 Animas 65 88 61 84 / 60 40 50 40 Hachita 64 86 61 83 / 50 30 40 30 Antelope Wells 63 85 61 84 / 50 50 50 50 Cloverdale 62 82 60 79 / 50 50 50 50 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$ 25-Hardiman / 26-Grzywacz
Area Forecast Discussion
National Weather Service Grand Rapids MI
1119 PM EDT Fri Sep 13 2019 LATEST UPDATE... Update .SYNOPSIS... Issued at 313 PM EDT Fri Sep 13 2019 - Storms exiting this evening - Chance for showers and thunderstorms Sunday - Dry with seasonal temperatures in the 70s most of next week && .UPDATE... Issued at 1119 PM EDT Fri Sep 13 2019 I have increased the chance for rain and thunderstorms for late Saturday night into Sunday based on the latest Hi Res model runs. Both the NAM and HRRR 36 hour run from 00z show a 30 to 50 knot low level jet aimed as Southwest Michigan Sunday morning. This is aided by a digging 80 to 90 knot 300 mb jet on the back side of digging northern stream wave. All of these features support good moisture transport into Southwest Michigan during the early morning hours of Sunday. There is thin cape early and EL levels rise to near 42000 ft by afternoon Sunday. It seems to me there is an excellent chance of elevated thunderstorms with locally heavy rain west of US-131 and south of I-96. During the day there is enough instability for scattered thunderstorms. && .DISCUSSION...(This evening through next Friday) Issued at 313 PM EDT Fri Sep 13 2019 -- Storms exiting this evening -- Strong to severe convection has initiated along a northeast to southwest line located just southeast of Jackson County. This effectively removes our chances for thunder and have updated the forecast accordingly. -- Chance for showers and thunderstorms Sunday -- Showers and thunderstorms will be possible from midnight Saturday night into early Sunday night. Precipitation amounts should not be heavy and overall chances for measurable precipitation are only in the 30% range at this time which is not substantially different from the previous forecast. It is possible rain chances could increase as we get closer to the event. Forecast reasoning: Synoptic conditions do not favor significant rain due to surface high pressure between us and the Gulf of Mexico limiting moisture return. The upper forcing is characterized by a minor upper trough in northwest flow aloft. It is not uncommon for models to sharpen these features as we get closer to the event, so we could see a more refined time window and an uptick in PoPs with subsequent forecast updates. A sharper trough would also boost thunder chances due to stronger mid-level cooling / height falls. -- Dry with seasonal temperatures in the 70s most of next week -- Confidence is fairly high for dry conditions Monday through Wednesday. There will be a gradual warmup with highs possibly reaching the low 80s towards the latter half of the week. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 728 PM EDT Fri Sep 13 2019 With the passage of the cold front had cleared out low clouds this afternoon. However as typical of a deeply occluded storm system (which is what has come through this area) there is an area of MVFR/VFR cigs low clouds in the coldest air trailing the system. The MVFR cigs are over northern WI and likely will stay north of our TAF sites tonight, but I do believe VFR cigs are likely. The low clouds should move out by mid morning Saturday resulting in mostly clear skies. Winds will slowly diminish this evening and should be more in the 5 to 15 knot range tomorrow. && .MARINE... Issued at 313 PM EDT Fri Sep 13 2019 Latest guidance suggests Small Craft Advisory conditions will cease by mid-morning Saturday. However will leave the current afternoon expiration time alone for now to see if this trend in the forecast guidance continues. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory until 5 PM EDT Saturday for LMZ845>849. && $$ UPDATE...WDM SYNOPSIS...TJT DISCUSSION...TJT AVIATION...WDM MARINE...TJT
Area Forecast Discussion
National Weather Service Jacksonville FL
942 PM EDT Fri Sep 13 2019 .UPDATE...A band of fast moving showers approaching the St Johns CO coast in the next hour will bring brief downpours and gusty winds. High-res HRRR indicates more bands of showers moving ashore the coast overnite so will be keep pops going for coastal areas. Brief downpours and storms possible. && .AVIATION...Ocnl MVFR from shra at the Taf sites til around 03Z- 04Z. Otherwise prevailing VFR with spotty light showers possible tonight. Gusty NE winds at SGJ...CRG...and SSI. && .MARINE...Moderate ENE winds will continue between high pressure north of the waters and TD Nine over the Bahamas. Winds will increase and waves will build through Sunday as this system moves north and then northeast into early next week. Advisory conditions expected over all the waters this weekend and may need a Tropical Storm Watch for the ne Fl waters. Local mariners should monitor the latest official forecasts from the National Hurricane Center. Coastal Impacts: Minor coastal flooding possible this weekend at the east coast beaches and along the St. Johns River due to high astronomical tides and increasing onshore winds. Rip Currents: High risk of rip currents today through the weekend due to persistent onshore winds and rough surf. && .PRELIMINARY POINT TEMPS/POPS... AMG 72 89 73 86 / 0 10 10 50 SSI 78 87 76 84 / 10 20 50 60 JAX 76 87 75 86 / 20 50 50 60 SGJ 77 86 75 86 / 30 80 60 60 GNV 74 87 74 88 / 10 40 30 60 OCF 74 88 74 89 / 10 60 30 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through Sunday evening for Coastal Duval- Coastal Flagler-Coastal Nassau-Coastal St. Johns. GA...None. AM...Small Craft Advisory until 8 PM EDT Monday for Waters from Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM- Waters from Fernandina Beach to St. Augustine FL from 20 to 60 NM-Waters from St. Augustine to Flagler Beach FL from 20 to 60 NM. Small Craft Advisory until 8 PM EDT Sunday for Coastal waters from Fernandina Beach to St. Augustine FL out 20 NM-Coastal waters from St. Augustine to Flagler Beach FL out 20 NM. Small Craft Advisory from 8 AM Saturday to 8 PM EDT Sunday for Coastal waters from Altamaha Sound to Fernandina Beach FL out 20 NM. && $$ PP/LS/TH
Area Forecast Discussion
National Weather Service Phoenix AZ
434 PM MST Fri Sep 13 2019 .UPDATE...Updated aviation discussion. && .SYNOPSIS... Conditions will continue to moisten through Saturday with chances for strong to severe thunderstorms increasing markedly across south-central Arizona. The threat for storms will continue Sunday, but will mainly be relegated to eastern Arizona. A low pressure system moving into the Great Basin early next week will allow for mostly slight chances of showers and thunderstorms on Monday and Tuesday before drier and somewhat cooler air overspreads the Desert Southwest. && .DISCUSSION... Western extension of the southern CONUS ridge remains sprawled across the Desert Southwest. In the lower levels, conditions are exceptionally dry with dewpoints in the 30s, though with the ridge axis lifting northward, low-level mixing ratios will increase steadily to around 10 g/kg through tomorrow. Latest runs of the HRRR indicate that isolated showers will remain relegated to southeastern Arizona this afternoon. Biggest weather impact will instead be the above normal temperatures, however highs will fall well short of daily records. Focus will shift to an increased threat of monsoon hazards Saturday as the models suggest ingredients will come together to produce strong to severe storms across portions of the area. Latest streamline analysis depicts an upper low near the northern Baja Peninsula, which will drift eastward into northern Sonora, yielding widespread jet-forced ascent across eastern Arizona. Convection will ensue across southeastern Arizona, which the models suggest will induce an organized inverted trough/vort max across eastern Arizona. This will consequently increase the easterly component to the steering flow off the higher terrain. Local/regional CAMS indicate that additional storms in the lower deserts are expected to initiate, given the abundant MUCAPE > 1000 J/kg. Although model soundings indicate inhibition (due to a mid-level warm layer) will be present to some degree, it is expected to erode during the afternoon and should be overcome by any downslope-propagating outflow boundary. Latest HREF > 40 dbz paintball and max surface winds suggest the most intense cells Saturday will be capable of producing strong to severe winds, microbursts and frequent lightning. Although PWATs are not projected to be off the chart by any means, heavy rain and subsequent flash flooding cannot be ruled out, particularly across the urban areas of the Valley. Forecast PoPS were increased above the latest NBM guidance and are some of the highest we`ve seen so far this Monsoon season. SPC has also placed much of the forecast area into a Marginal Risk for severe storms, however this could be upgraded as the situation evolves. A more distinct low pressure system (as depicted in both the operational GFS and ECMWF) will likely emerge across eastern Arizona Sunday, again resulting in favorable conditions for thunderstorms. However, the southwesterly flow will generally focus activity across eastern Arizona, though there will be a discernible risk of flash flooding across portions of the Gila County, where PWATS remain anomalously high. Further west in the lower deserts, rain coverage will likely not be quite as widespread, given the environment will be more subsident behind the departing low pressure system. && .PREVIOUS DISCUSSION... The track of the Pacific trough for early next week now looks to be even farther north with the low center tracking across northern Nevada into southern Idaho. We will still fall under cyclonic flow aloft early next week and there should be enough lingering low level moisture for some showers and thunderstorms mainly on Monday and mostly over the high terrain north and east of Phoenix. Slight chance PoPs are still in for the south-central Arizona lower deserts, but it seems likely most of the activity will be over the more favored upslope foothills areas just north and east of Phoenix. Drying aloft will increase into Tuesday, ending rain chances across the lower deserts, but there may still be some isolated showers and possibly a few thunderstorms over the eastern Arizona high terrain. Temperatures will lower back to near normal readings beginning Sunday with highs sticking around the century mark across the deserts through the middle of next week. && .AVIATION...Updated at 2345Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Dry, tranquil conditions expected at the terminals this evening with thunderstorms mostly remaining across southeast Arizona. As a result of this activity, a weak southeasterly outflow may reach the terminals after 04Z but speeds should remain light. Westerly winds will transition later tonight to the southeast. Going into Saturday afternoon, winds look to maintain a southeasterly component with no typical diurnal switch to the west during the afternoon. Tomorrow afternoon/evening looks to be an active period where south-central Arizona will experience increasing thunderstorm activity. The main threats with these storms will be strong, gusty winds along with lightning. Maintained VCTS in the TAF after 23Z at KIWA and 00Z at KPHX, with gusts up to 30 kt possible. Areas of blowing dust may also affect area terminals, with visibilities perhaps down to 5 SM at KIWA. Otherwise, FEW- SCT mid and high level clouds are expected through late tomorrow afternoon with bases generally remaining aoa 10 kft, before thicker cloud cover with bases down to 8 kft possible with increased thunderstorm activity. Southeast California/Southwest Arizona including KIPL and KBLH: No significant aviation concerns expected through the period as light winds and VFR conditions prevail. Wind speeds through the next 24 hours look to remain below 8 kts becoming light and variable at times. Otherwise, FEW-SCT high clouds will be possible through the TAF period. Aviation Discussion not updated for amended TAFs. && .FIRE WEATHER... Monday through Friday: A series of low pressure systems will move through the Pacific Northwest and Great Basin next week. Conditions will remain sufficiently moist ahead of the first system for a chance of showers, mainly north and east of Phoenix Monday and Tuesday. Otherwise, these storm systems will reinforce the westerly flow, which will result in a gradual drying trend and near normal temperatures. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Hirsch PREVIOUS DISCUSSION...Kuhlman AVIATION...Rogers/Smith FIRE WEATHER...Hirsch