Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/14/19

Area Forecast Discussion
National Weather Service Amarillo TX
635 PM CDT Thu Jun 13 2019 .AVIATION...00z TAFS... VFR conditions expected at all TAF sites. Thunderstorms will be possible in the 0-6z time frame, with the expectation that any remain storms should be east of the terminals by 06z. Cigs will increase coverage with initial heights around 20kft AGL, given the thunderstorm anvils. Thereafter, expect any thunderstorm bases to be around 6kft AGL. Winds will still be breezy out of the south in the 15-20kt range gusting 25-30kts through about 10z. Low level jet will set up and there will be a period of WS in the TAFS from the overnight time through about 12z. Small chance of storms in the 18z-00z time period, but that will be refined with later TAF packages. Weber && .PREV DISCUSSION... /Issued 256 PM CDT Thu Jun 13 2019/ SHORT TERM...Tonight and Friday... Forecast is still on track for anticipated thunderstorms later today. Severe weather is expected to develop and impact the Panhandles through the evening hours. At least one or two supercells will be possible before storm mode becomes more cluster/linear. Main threats will be damaging wind gusts of 60-70 mph, hail upwards near 2.00", and possible flash flooding due to slow storm mode and high rainfall rates around 1"/hr coupled with already saturated soils. We are currently tracking a subtle but potentially potent shortwave that is noteably in both upper air charts and water vapor. Watching for the timing of this with an expected surface trough for storm initiation and evolution. Breezy southerly flow is expected today which will aid in strong theta-e advection along the western fringe of the forecast area given our forecast dew points. We could easily hit 1500-2000 J/kg MLCAPE this afternoon along western parts of the forecast area where thunderstorms should initiate. RAP is forecasting 40-50 knots of effective shear, which is likely to produce strong rotating updrafts in at least a couple thunderstorms. Supercell storm mode will be anticipated early on before the upper level wave pushes east and likely makes a scenario more favorable for cluster type mode. Low level helicity values are impressive after 7pm, but LCL heights will likely be too high for a tornado threat in any supercell. This is something in particular we need to monitor closely, especially if storms go more linear as quick spin- ups are possible in the lower LCL height environment. AS activity pushes east we should start to see a decrease in threats, especially after midnight. Thunderstorms will exit the region by early Friday morning. Thunderstorms are possible Friday by this is very conditional and we may end up being convection free through the afternoon hours. That said, tomorrow is going to be our warmest day of the year as widespread 90 degree temperatures are anticipated. The Palo Duro Canyon may very well hit 100-105, so any Canyon goers should be prepared for hot conditions. LONG TERM...Friday Night through Wednesday Night... Westerly flow aloft will continue. Right now it looks like the dryline will mix somewhere near the Amarillo area, with strong capping east of the dryline. Subtle shortwave to the north may allow for storms to trigger along the northeast OK Panhandle. Otherwise, best chance of storms will be along the dryline where the convergence is strongest. Models not putting out too much QPF and soundings indicate that it still may be just capped enough to limit storm development. (Still will not rule out isolated storms east of the dryline, so for now going with 20 pops, against a drier guidance.) Saturday flow aloft will become more southwesterly as weakly amplified trof will pass through the Panhandles. ML CAPE values are off the charts in the afternoon, in the 3000-4500 J/kg range. Certainly will be a chance of storms, and storms that develop will be severe on Saturday. There is the potential for very large hail (Baseball or larger)and strong damaging winds. LCL`s will be pretty high across the southern Panhandles, but will drop off below 1000m across the OK Panhandle in the evening. This will increase the tornado threat. There is the chance that the southern Panhandles will be dry-slotted as the thermal ridge sets up just over the area. So the focus for the severe weather at this time would be north of the I-40 corridor, and east of Amarillo. Cooler air will be in place on the back side of the wave as a lee surface high sets up over eastern CO. Surface flow will start off out of the north and become easterly on Sunday, as another surface high dives down from Canada and lingers over northeast NE. This will help advect surface dewpoints back into the 60s, while weak mid level flow out of the west and northwest will help bring Pacific moisture to the area. ML CAPE values in the 1000-2000 J/kg range will open up the potential for strong to severe storms again on Sunday. Models want to trigger storms off the mountains, in association with subtle mid level wave`s moving through. Best chances of storms will be across the west. The same flow regime is expected to continue on Monday and Tuesday providing more round of storms to the Panhandles. Dryline may mix enough east on Tuesday to keep the southwestern Panhandles dry. But there is some uncertainty. As we move into Wednesday northwest flow still looks to prevail, but drier air in the mid levels will help to shut down the thunderstorm chances, as well as the dryline expected to mix to the central Panhandles, possibly as far east as the OK state line. Weber && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 61 94 65 92 60 / 40 10 5 10 20 Beaver OK 60 93 62 89 60 / 30 10 20 20 40 Boise City OK 57 93 57 84 55 / 50 10 10 40 40 Borger TX 62 96 65 92 62 / 50 10 5 20 30 Boys Ranch TX 62 97 62 92 60 / 40 10 5 20 30 Canyon TX 61 96 64 94 60 / 40 10 5 5 10 Clarendon TX 62 93 68 94 63 / 50 10 5 0 20 Dalhart TX 58 94 57 87 56 / 40 10 5 20 30 Guymon OK 60 93 59 87 58 / 40 10 10 30 50 Hereford TX 63 97 63 95 60 / 30 10 5 5 10 Lipscomb TX 61 93 66 92 62 / 40 10 10 20 40 Pampa TX 60 92 65 91 61 / 50 10 5 10 30 Shamrock TX 61 91 68 95 65 / 50 10 10 5 30 Wellington TX 63 93 70 97 66 / 40 10 10 5 30 && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$ 89/24/89
Area Forecast Discussion
National Weather Service La Crosse WI
636 PM CDT Thu Jun 13 2019 .SHORT TERM...(This evening through Friday night) Issued at 225 PM CDT Thu Jun 13 2019 Main forecast concerns for tonight are on chances for showers and thunderstorms. Scattered showers and isolated thunderstorms look to develop across portions of the area after midnight tonight and continue through around mid morning on Friday. 850 mb moisture transport focuses into the area tonight and on the leading edge of this we should see the showers/isolated thunderstorm activity develop. MUCAPE values aren`t overly impressive based on RAP forecast soundings but the NAM places nearly 500 J/kg of CAPE when lifting a parcel from just above 850 mb. Thinking the NAM moisture profile may be a bit overdone with drier air in place so leaning more toward the RAP with isolated thunderstorms in the forecast. Expect an accas field to develop tonight before we see the showers and isolated storms develop shortly after midnight. Many CAMS also support the scattered showers and isolated storms tonight with the most concentrated area for this activity along and east of the Mississippi River. Plan on increasing winds across the area around or shortly after sunrise on Friday as a tight pressure gradient develops over the area. Additional showers/storms will likely develop later in the afternoon or the evening across northern WI near near a front slowly sagging south. A few stronger storms are possible mainly north of I-94 with 30 kts of 0-3 km shear SBCAPE around 1000 J/kg. Highs will be mainly in the 70s. Winds will also be breezy from the southwest ahead of surface low pressure across the northern plains with gusts over 30 mph possible. .LONG TERM...(Saturday through Thursday) Issued at 225 PM CDT Thu Jun 13 2019 A messy west to northwest flow pattern is expected through the weekend. An elongated surface trough/cold front extending from the northern plains into the Midwest will continue to be the focus for convection into the weekend. Although the stronger moisture transport shifts off to the southeast on Saturday, models indicate potential for the plume of moderate MLCAPE south of the surface boundary (near and south of I-90). If this materializes and depending on timing of the front, could not rule out a few strong storms with some 0-3 km shear, although this potential to looks higher farther south and west. Mild temps in the 70s to low 80s are expected. By Sunday the front will be dragged to the south, although showers/isolated storms are still possible as a stronger upper shortwave trough swings across the northern Great Lakes with a surface through 850 mb trough extending east from the northern plains. Cooler temps in the mid 60s to mid 70s are expected. Mainly dry and seasonable weather is expected to start the work week with an influx of drier air and weak high pressure from the north. Highs will generally be in the 70s with lows in the 50s (40s over parts of central WI). Although deterministic and ensemble guidance exhibit plenty of variability towards the mid/late next week, consensus favors some increasing rain chances as some degree of troughing develops across the Rockies into the plains. However, forecast confidence is very low in this pattern. Temps look to remain seasonable through next week. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 636 PM CDT Thu Jun 13 2019 VFR conditions are envisioned for the area the next 24 hours, with clear skies early on giving way to increasing mid level clouds in the 7-12kft range through the evening, earliest at RST where persistent cloud development is already ongoing just to the west (ahead of earlier expectations). Can`t rule out a few showers at either RST or LSE later tonight as those clouds increase, but the risk appears pretty low at this point with not much instability available. Bigger story will be low level wind shear development later tonight for all areas, before surface winds become quite gusty in the 25-30 knot range into mid and late morning, as mid level clouds also hang on through much of the day on Friday. Can`t completely rule out a few additional showers at any point on Friday, though the risk is low for RST/LSE as the better thunderstorms will focus farther north along an approaching cold front into central Minnesota and northern Wisconsin. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Wetenkamp/JM LONG TERM...JM AVIATION...Lawrence
Area Forecast Discussion
National Weather Service Dodge City KS
619 PM CDT Thu Jun 13 2019 ...Updated aviation discussion... .SHORT TERM...(This afternoon through Friday night) Issued at 1200 PM CDT Thu Jun 13 2019 South winds will become strong this afternoon. With pressure gradients increasing to 10-11 mb across the CWA, south wind gusts of 30-40 mph will be common through 7 pm. Moisture and instability will as a result be on a gradual increase through this afternoon, but with the lack of a triggering mechanism, feel SW Kansas will remain mostly quiet (and perhaps completely quiet) with regards to convection through this evening. Models remain consistent developing an instability axis along the CO/KS border by 7 pm, with modest CAPE values to near 2000 J/kg. Any convective initiation would be favored in the far western zones through this evening. The latest HRRR iterations show convection originating east of the Raton Mesa, ending up near Elkhart by 6-7 pm, before an MCS evolves across the Texas panhandle this evening. Model guidance has been consistent with this solution for days, and am confident most if not all storms will be south of SW Kansas through tonight. Out of respect for a strong low level jet and associated elevated instability, kept slight chance (20%) pops for most zones tonight, with 30% pops across the southern border nearest the expected MCS. South winds will remain elevated tonight, gusting 20-25 mph, and with a well mixed boundary layer, temperatures through Friday morning will be much warmer than recent nights (and much closer to normal), holding near 60. Friday will be noticeably warmer, as 850 mb temperatures warm to the mid 20s C range. Expect highs in the upper 80s east to the lower 90s west. Feel with lush vegetation, moisture advection, and lack of downslope, many locales will fall short of 90. Still, one of the warmest days we`ve had this season. South winds will not be as strong Friday, adding to the warm and humid feel to the air. Strong instability will build through the afternoon with CAPE to near 4000 J/kg. Most of daylight Friday will be dry for most of SW Kansas, as this instability builds. Am confident that strong to severe convection will impact portions of SW Kansas Friday evening, but mode and placement are still somewhat muddled. GFS has shown an MCS tracking across the northern zones Friday evening for many runs now. CAMs show good agreement with convection in the western zones by 7 pm Friday. Focused scattered category pops in the Friday evening time frame. Slow moving supercells with a primary threat of large hail are possible, per the 15% slight risk from SPC, but damaging winds are likely from any MCS. Active convective operations are expected Friday PM. .LONG TERM...(Saturday through Thursday) Issued at 150 PM CDT Thu Jun 13 2019 Another round of strong to severe convection is expected Saturday afternoon and Saturday night. 12z ECMWF as well as many other models depict a discernible shortwave trough arriving in SW Kansas, well-timed with peak heating Saturday afternoon. Models continue to focus the strongest instability across the SE 1/2 of the zones, with extreme CAPE values of over 5000 J/kg possible. 12z ECMWF shows convective initiation in this high instability environment Saturday afternoon. Shear values will be augmented by the approaching shortwave, such that supercells are likely within the first several hours of convective evolution. Very large hail is the primary threat, again primarily east and south of Dodge City as a first approximation. 12z ECMWF maintains continuity from its previous runs, showing a strong MCS along the Kansas/Oklahoma border Saturday evening. Sunday through Tuesday, the details remain unknown, but the trend is clear. Thunderstorm chances will continue throughout this time range, as weak shortwaves interact with moisture and instability. Location, coverage and severity will need to be determined essentially on a day-by-day basis. Pop grids in the 20-50% range are spread out nicely Sunday through Tuesday by the NBM, and that will suffice for now. There are indications that drier air from the west will shut down the thunderstorm machine late next week. Temperatures will change little day-to-day, with highs in the upper 70s to mid 80s common, and lows in the 50s NW to 60s SE. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 619 PM CDT Thu Jun 13 2019 Isolated thunderstorms in southeast Colorado will move east and southeast early this evening. Most of the convective activity is expected to move into the OK/TX panhandles but a few storms could stray into far southwest Kansas this evening. The storms should be weakening with the loss of daytime heating but will carry at least a mention of VCSH at the Liberal terminal. Late this evening into tonight, a low level jet is expected to develop. In addition to LLWS at the terminals, this feature could result in some nocturnal convection over central Kansas. Do not have real high confidence in this but will carry a period of VCTS at Hays for that possibility. && .PRELIMINARY POINT TEMPS/POPS... DDC 60 88 61 87 / 20 10 30 20 GCK 60 88 58 87 / 20 20 30 30 EHA 60 93 58 86 / 50 10 10 40 LBL 59 91 60 87 / 30 10 20 20 HYS 61 89 62 87 / 30 20 50 20 P28 62 87 66 90 / 30 10 30 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Turner LONG TERM...Turner AVIATION...Gerard
Area Forecast Discussion
National Weather Service Duluth MN
1020 PM CDT Thu Jun 13 2019 .UPDATE... Issued at 956 PM CDT Thu Jun 13 2019 Please see the updated Marine discussion below. UPDATE Issued at 645 PM CDT Thu Jun 13 2019 Please see the 00Z aviation discussion below. && .SHORT TERM...(This evening through Friday) Issued at 340 PM CDT Thu Jun 13 2019 High pressure has led to plenty of sunshine and dry conditions this afternoon but the high will be moving off to the east tonight. A shortwave will move in tonight and combine with low level FGEN to produce showers and thunderstorms, mainly late tonight. The NAM and RAP are strongest with the FGEN compared to the GFS. We did include a mention of thunder to all areas tonight despite relatively low values of CAPE. However, in cases of stronger FGEN, even low values of CAPE will lead to some thunderstorms. We do not expect severe storms tonight. Shower/storm coverage should decrease Friday morning as the shortwave departs. However, a cold front will be moving south through northern Minnesota into far northern Wisconsin by Friday evening with the front continuing south Friday night. Showers and storms should again ramp up during the afternoon and evening, especially over our southern areas. SPC`s Day Two Outlook still shows a marginal risk over a good portion of the Northland. This is reasonable given the frontal boundary, FGEN, and afternoon/evening deep layer shear from 30 to 40 knots. The most likely time will be late afternoon into the evening. The main threats will be hail and damaging winds. However, FGEN is expected in the afternoon and evening, especially from central Minnesota into northern Wisconsin, which could enhance rainfall totals there leading to locally heavy rain. .LONG TERM...(Friday night through Thursday) Issued at 340 PM CDT Thu Jun 13 2019 A slow-moving upper-level trough will dig into the Upper Midwest Saturday and linger through Monday. The cool front which moved through the region Saturday night will stall out and become stationary over eastern South Dakota, southern Minnesota, and southern Wisconsin. Southerly flow over the front and falling heights as the trough moves in will keep a chance of rain and a few thunderstorms in the forecast Saturday through Sunday night. Widespread severe storms are not expected, but a few storms may be strong. Northeast winds off Lake Superior combined with mainly cloudy skies and cold air aloft will result in cool temperatures fore the weekend. Highs will be 5 to 15 degrees below normal. Temperatures begin to climb to near normal Monday and Tuesday. The upper-level trough will slide off to the east with northwest flow returning to the region. With a wide spread of deterministic and ensemble solutions for the forecast details Monday and beyond, have kept rain chances in the forecast Tuesday through Wednesday night. A few storms may be strong during the period, but widespread severe weather is not anticipated. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 645 PM CDT Thu Jun 13 2019 VFR through about 09Z, but then MVFR with occasional IFR through the morning and early afternoon hours, then a return back to VFR at around 20Z. Skies will be mostly clear aside from a few high clouds through about 06Z as high pressure moves to the east. A shortwave will bring increasing clouds with showers and thunderstorms by morning. The worst conditions are expected in HIB and DLH with some storms affecting INL, HYR, and BRD as well. IFR ceilings are possible Friday morning especially at HIB and DLH with some fog possible. Ceilings and visibilities will improve to VFR from north to south Friday afternoon as a cold front moves south. Additional showers and thunderstorms will likely develop along the cold front late Friday evening, which may impact mainly BRD and HYR. A few of these storms could be strong to severe. && .MARINE... Issued at 956 PM CDT Thu Jun 13 2019 Winds will be southwesterly overnight with speeds up to 15 knots, causing wave heights generally under 3 feet. Winds will become variable friday afternoon before switching to the northeast during the evening as a cold front moves across Lake Superior from north to south. Speeds will generally range from 5 to 10 knots through Saturday except up to 15 knots near the western tip of Lake Superior. Wave heights will generally be 2 feet or less. Showers and thunderstorms are possible late tonight through Friday night which could cause locally higher wind speeds and wave heights. && .PRELIMINARY POINT TEMPS/POPS... DLH 47 72 43 60 / 70 70 40 30 INL 50 72 45 65 / 50 40 20 30 BRD 52 80 54 69 / 40 50 60 40 HYR 48 76 50 69 / 50 60 50 40 ASX 48 72 45 61 / 60 70 40 30 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...None. && $$ UPDATE...JS SHORT TERM...Melde LONG TERM...Huyck AVIATION...JS MARINE...JS
Area Forecast Discussion...CORRECTED
National Weather Service Riverton WY
235 PM MDT Thu Jun 13 2019 .SHORT TERM...(This afternoon through Friday night) Issued at 1 PM MDT Thu Jun 13 2019 At the time of this writing, a very distinct weather feature is showing up on the satl loop with a sharp area of drying underneath it which is now the culprit producing lightning just east of Pinedale near the West Fort RX burn not far from the White Pine Ski Resort. This feature should arrive in the Riverton area as well as the vicinity of Sweetwater Station by noon, and the Casper area by 2 pm this afternoon. The area of marginal risk as indicated by SPC appears to surround this area of convection as well as where it is headed. Would not be surprised if SPC extends it far enough to the east to include Casper since this will occur during the favorable time of max heating this afternoon. Meanwhile, the cluster of convection that was scooting east across Northern Wyoming overnight last night is dissipating. The HRRR does show a couple of more bands of convection behind the one associated with the most prominently visible shortwave, as the environment will quickly recover to support additional convection for these additional anticipated bands of showers. The second band of convection will likely swing across the CWA during the mid afternoon hours today, and yet another one coming through from west to east during the early evening hours. And finally, another cluster of convection is anticipated to march east across Sweetwater County between 04 and 08z tonight, associated with another weak ripple/vort lobe within the west northwest steering flow. Then on Friday afternoon, a distinct shortwave is due through the area which will result in even more numerous showers and thunderstorms Friday, but not as strong as the ones anticipated for today. This is because of the added cloudiness and cooler temperatures anticipated for Friday. Much of this shower and thunderstorm activity will continue through Friday night as yet another even more distinct shortwave, that will track a little farther north than the one on Friday afternoon, tracks through by 12Z Saturday. Capes and negative lifted indices will be strong enough to support the anticipated significant convection this afternoon through Friday. NAM PWATS of 0.50 to 0.75 of an inch will be common this afternoon through Friday. Small hail, heavy rainfall rates, and gusty winds are expected with many of these thunderstorms through Friday. Isolated large hail and damaging winds are a possibility this afternoon and early evening as well. .LONG TERM...(Saturday through Thursday) Issued at 1 PM MDT Thu Jun 13 2019 Weak to modest west to northwest mid-upper level winds are expected Saturday through Monday with subtle shortwaves in the flow. At the surface, a quasi-stationary weak boundary will be east of the Divide. Diurnal convection is expected each afternoon and evening. The weak frontal boundary could help initiate diurnal convection along the Divide and Bighorn Mountains with the convection pushing east into the lower elevations. The driest area over this period will be over the southwest. A strong easterly Pacific jet (120-140kt at 250mb) will overspread the northern Rockies Tuesday and Wednesday in an overall low- amplitude broad trough that develops across the northern tier of states into Canada with embedded upper-mid level lows. The placement of the upper jet across the N. Rockies will depend on how robust/widespread convection will be across the forecast area. Winds will be breezy to windy beginning Tuesday in some areas, and spread across much of the area by Wednesday and Thursday. The associated cold front timing currently looks to be late Wednesday into Wednesday night. The best chances of convection will be over the north with the driest areas over the south. High temperatures are expected to be seasonal or slightly below average, while lows look to be seasonal to slightly above average. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 1 PM MDT Thu Jun 13 2019 Isolated to scattered thunderstorms are expected across the entire area this afternoon and last into the evening. The convection should dissipate in most areas by around 04Z. The stronger thunderstorms into early this evening are capable of producing wind gusts 40 to 50kt and hail. Another round of showers is expected to impact southern areas including the KRKS late tonight. Showers and thunderstorms are again expected Friday afternoon, however the intensity and coverage are expected to less. Brief MVFR/IFR conditions are expected with any convection. Outside of convection, VFR conditions are expected. && .FIRE WEATHER... Issued AT 1 PM MDT Thu Jun 13 2019 Several bands of thunderstorms are expected to march east across Western and central Wyoming for the remainder of this afternoon and evening, and will likely continue in zone 279 past midnight tonight. Some of these thunderstorms could produce sizable hail and strong gusty winds, as well as locally heavy rainfall and frequent lightning. Friday will feature another round of more numerous showers and thunderstorms along with somewhat cooler temperatures. However, the thunderstorms that occur Friday should not be quite as intense as the ones that occur this afternoon and evening. A daily risk of late day scattered showers and thunderstorms will continue into early next week along with mostly seasonable temperatures. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Lipson LONG TERM...Murrell AVIATION...Murrell FIRE WEATHER...Lipson