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

National Weather Service Albany NY
1025 PM EDT Tue Jun 18 2019 .SYNOPSIS... Fair weather is expected tonight and Wednesday. Some isolated showers and thunderstorms are possible Wednesday. A storm system moving through the mid Atlantic states may bring a steady rainfall Thursday into Friday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... As of 1020 PM EDT...Just a few residual showers across the Adirondacks which is across a diffuse boundary (and lake boundary from earlier in the day) that extends southwest toward the Finger Lakes region. HRRR suggests some of these upstream showers may approach the western areas while they dissipate. Otherwise, per the H2O vapor loop, ample moisture remains in place as variable cloud coverage with light and variable winds. If enough breaks occur overnight, especially where rain fell earlier in the day, patchy fog will be the result. Prev Disc... Rain in the process of exiting the southern Berkshires, mid Hudson Valley and NW CT. There is some clearing behind the area of rain and much of the night should be partly cloudy to mostly clear outside of some areas of high clouds, and some patchy fog developing in some areas after midnight. The patchy fog and lingering trapped low level moisture beneath mid and upper level dry air, could contribute to the development of some low clouds in some areas before and around sunrise. Still, light winds and some weak subsidence through the night will help temperatures fall to the mid 50s to around 60. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... There are really no well defined upper impulses seen in data or sources of guidance/ensembles affecting our region through Wednesday night. The diffuse low level wind shift and moisture boundary to our south is expected to drift very slowly north as upper heights very slowly rise within the northern periphery of flat upper ridging. So, mid and upper level dry air will be in place over much of the region with low level moisture and boundary layer temperatures slowly rising. There could be an isolated to scattered shower or thunderstorm mainly Wednesday afternoon and evening but there should also be enough sun to get temperatures solidly into the 70s to around 80. By Thursday, well defined upper energy tracking across the midwest and OH Valley will approach our region. There are still differences in sources of guidance/ensembles in terms of how far north the greater instability and stronger low level forcing gets. The best coverage of showers Thursday morning will be in western and northern areas but some scattered showers could develop into eastern NY and western New England by early afternoon. There should be more clouds than sun for most of Thursday, especially in western and northern areas, then becoming cloudy everywhere through the afternoon as showers and thunderstorms expand across the entire region. Areas from the eastern Catskills through mid Hudson Valley through NW CT have the best chance at more significant instability and being in the leading convergent zone of a low level jet segment and thermal moisture boundary along the cold front. Again, there are sources of guidance that keep the significant instability south of our region but boundary layer and midlevel convergence within some semblance of a developing upper deformation zone north of the stronger convection could provide embedded convective elements and locally heavy rain extending north through our entire forecast area later Thursday afternoon through much of Thursday night. Chances for severe thunderstorms and the potential for localized urban and small stream flooding will continue to be monitored. Highs Thursday in the lower to mid 70s but around 70 north and upper 70s southern areas. Rain exits through Friday morning and improving sky with low level drying and cooling expected through Friday afternoon. It could be quite breezy Friday afternoon as well. Highs Friday in the upper 60s to mid 70s. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... Several discrepancies remain in the long term portion of this forecast as the latest version of the GFS-FV3, ECMWF, GGEM and ICON all vary to the extend of the trough amplification across the northeast and upstream progression of the approaching warm front. There is rather high confidence that the upcoming weekend period should remain dry as upper low and surface lows become vertically stacked in the Canadian maritimes. This places our region within a northwest flow regime with slowly rising heights and surface ridge axis sliding southeastward across the region. There might be enough of a cold pool aloft for terrain based clouds and isolated showers to the north and east of Albany but we will keep conditions dry in the forecast at this time. Near seasonable temperatures too for the first weekend of summer with average highs into the 70s and near 80F for valley locations and overnight lows into the 50s and near 60F for valley locations. Heading into the first full week of summer, models diverge further with the GFS-FV3 more aggressive with the upstream warm front approach than the ECMWF/GGEM/ICON. Mixed ensemble signals as well with some hints of the ridge holding on a little strong to extend our dry weather pattern through Tuesday. However, per coordination and still some chance, we will continue with the previous forecast for some showers and perhaps a thunderstorm through early next week. The thermal profiles do moderate as it would seem with a late June sunshine we should see more 80s evolve for valley locations and overnight lows moderate into the 60s. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... As showers dissipate, we are left with light and variable winds along with borderline VFR/MVFR conditions. Expectations are for flight conditions to become MVFR and possibly IFR with patchy fog/low-stratus developing overnight. The low-level moisture will gradually mix out by mid-morning Wednesday, with perhaps a few showers popping up by Wednesday afternoon. Winds will remain light throughout the TAF period. Outlook... Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. Thursday: High Operational Impact. Definite SHRA...TSRA. Thursday Night: High Operational Impact. Definite SHRA...TSRA. Friday: Low Operational Impact. Breezy Isolated SHRA. Friday Night: No Operational Impact. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: No Operational Impact. NO SIG WX. Sunday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... Fair weather is expected tonight and Wednesday. Some isolated showers and thunderstorms are possible Wednesday. A storm system moving through the mid Atlantic states may bring a steady rainfall Thursday into Friday. RH values will exceed 45 percent through Thursday with near 100 percent tonight and Wednesday night. Widespread showers and scattered thunderstorms are expected Thursday. Winds tonight will be light and variable. On Wednesday and Wednesday night, winds will be south to southwest at 10 mph or less. Winds Thursday will be northeast to southeast at 15 mph or less. && .HYDROLOGY... Isolated to scattered showers and thunderstorms are expected through Wednesday night. A wave of low pressure is expected to bring a widespread soaking rainfall Thursday into Friday with amounts between three quarters of an inch and an inch and a half. The rain is expected to cause only within bank rises on the main stem rivers. Please visit our Advanced Hydrologic Prediction Service /AHPS/ web page for specific area rivers and lakes observations and forecasts. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...NAS NEAR TERM...BGM/NAS SHORT TERM...NAS LONG TERM...BGM AVIATION...BGM/Thompson FIRE WEATHER...NAS HYDROLOGY...NAS
Area Forecast Discussion
National Weather Service Bismarck ND
1008 PM CDT Tue Jun 18 2019 .UPDATE... Issued at 1008 PM CDT Tue Jun 18 2019 Scattered thunderstorms over southwest and south central North Dakota have greatly diminished over the last hour. There has also been a diminishing trend in the convection approaching from eastern Montana. Given these trends along with the RAP now showing less than 500 J/kg MUCAPE overnight, opted to lower thunder potential to just a slight chance. Meanwhile, a small area of showers has been sitting over northwest Pierce and northeast McHenry Counties for the past few hours. It is not entirely clear what is causing this, though there may be a very weak disturbance in the vicinity, per water vapor imagery. Other changes for this update include adjusting PoPs and sky cover to better match short-term trends. Also increased low temperatures by a few degrees over western North Dakota, where cloud cover is increasing and dewpoints are expected to hold in the lower to mid 50s. UPDATE Issued at 714 PM CDT Tue Jun 18 2019 No major changes are needed for this update. Scattered thunderstorms continue across parts of southwest North Dakota early this evening. As of this writing, the strongest storm was located over central Grant County, which has exhibited some characteristics of a left-moving supercell. The expectation remains that these storms will slowly dissipate through the evening as diurnal instability begins to decrease. && .SHORT TERM...(This evening through Wednesday) Issued at 129 PM CDT Tue Jun 18 2019 Shower and thunderstorm chances will highlight the short term period of the forecast. Currently, low pressure is situated over far southeast Montana with perhaps a warm front east through northwest South Dakota, and then extending south from there. There is weak to moderate MUCape over southwest North Dakota. In addition a small area of 0-6km bulk shear is also situated over the same area. RAP forecast soundings indicate the greatest instability and shear will exist early to mid afternoon, before tapering into the late afternoon and early evening. The most likely severe threat would be quarter sized hail or locally severe gust. Area hodographs are not too impressive, but at least early this afternoon there is some minimal helicity. Although the overall chances are low, the far southwest would be most likely area for a brief severe storm this afternoon. Tonight, increasing warm advection will combine with shortwave energy which is currently exiting the northern Rockies. This will result in surface cyclogenesis in northwest South Dakota, with widespread showers and embedded thunderstorms spreading from western into central ND late tonight through Wednesday west to east across the forecast area. Initially, the threat of severe weather will be minimal, however, by Wednesday afternoon after the initial wave of shower and thunderstorm activity moves through, we could become slightly to moderately unstable over far southwest and far south central ND. For instance, the 12 UTC NAM forecast sounding for Ashley ND, indicates around 1200 J/KG of MUCAPE with 45kts of bulk shear and a nicely curved hodograph with abundant 0-3km helicity. The problem will be, actually clearing out and destabilize during the afternoon. It looks to be a pretty small window, with a much more stable atmosphere as you head north and less favorable of a shear/helicity setup as you get into the far southwest. Given the uncertainty, will not mention severe wording in the forecast at this time, but will segment out portions of the far southwest and far south central for marginal severe hazards. .LONG TERM...(Wednesday night through Tuesday) Issued at 129 PM CDT Tue Jun 18 2019 Showers and thunderstorms will continue into at least the early portions of the extended forecast. An upper level low becomes situated in the lee of the southern Canadian Rockies Wednesday night. A shortwave rounding the base of the low is expected to spark another round of showers and thunderstorms spreading southwest to northeast late Wednesday night through Thursday morning, and possibly lingering through the day over our northern and eastern counties. At this time it appears it will be cool enough that the threat of severe weather will be minimal. The far southwest could be a concern again as this would be the area to potentially see the sun break out and destabilize the atmosphere enough for moderate instability. But this is a bit too far out for any mention of severe at this time. The upper level low remains over the northern High Plains with the center of the low over northeast Montana by Friday afternoon. This will keep a good chance of showers and thunderstorms in the forecast through Friday. That upper low over northeast Montana lifts north of the area early in the weekend, but lingering upper level troughing remains over the area through the weekend, and then we transition to a brief quasi-zonal flow as another upper low takes shape off the Pacific Northwest Coast. This will keep at least a slight chance of showers and thunderstorms over the weekend and into early next week, but certainly not as widespread as this Wednesday through Friday. Temperatures will remain cool Through the work week, with several rounds of showers and thunderstorms. Then a little bit of a warming through through the weekend and into early next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 714 PM CDT Tue Jun 18 2019 VFR conditions are expected through the evening, although thunderstorms may approach KDIK through 03Z. Additional showers and storms are forecast to move into western ND late tonight, spreading east through Wednesday morning. MVFR ceilings are also expected to develop Wednesday morning across western and south central ND. Brief periods of MVFR visibility and gusty winds may be possible if a storm passes over a terminal. Otherwise, expect southeasterly winds around 10 kts Wednesday afternoon. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Hollan SHORT TERM...TWH LONG TERM...TWH AVIATION...Hollan
Area Forecast Discussion
National Weather Service Cheyenne WY
507 PM MDT Tue Jun 18 2019 .SHORT TERM...(This evening through Thursday) Issued at 110 PM MDT Tue Jun 18 2019 Tonight...As depicted with current radar trends, as well as the models indicating plenty of low and mid level moisture available along with a passing shortwave trough aloft, expect scattered to numerous showers and thunderstorms this evening, with a decrease in areal trends after midnight. Some of the storms may produce locally heavy rainfall considering precipitable water values. Wednesday...Drier, warmer and windy as the low level winds turns westerly, helping to advect in drier air at low and mid levels. Looks like enough moisture for isolated late day showers and thunderstorms mainly east of Interstate 25. Will need to watch the projected winds over our wind prone locations. Thursday...The flow aloft backs to west southwest in advance of the next approaching trough. This will induce surface low pressure over southeast Wyoming and the available moisture will combine with low level convergence to produce scattered to numerous showers and thunderstorms in the afternoon and evening. .LONG TERM...(Thursday night through Tuesday) Issued at 110 PM MDT Tue Jun 18 2019 Friday...Similar coverage of showers and thunderstorms compared to Thursday, although temperatures will be cooler with more cloud cover and in the wake of a passing cold front. Saturday...Even cooler with more cloud cover and chances for showers and thunderstorms in advance of the approaching trough aloft over western Colorado. Sunday...Chances for late day showers and thunderstorms will continue with the passing of a shortwave trough aloft, though temperatures will be warmer with more sunshine compared to Saturday. Monday...The flow aloft becomes zonal with weak shortwave ridging aloft overhead. Looks like adequate low and mid level moisture for isolated afternoon and evening showers and thunderstorms. Tuesday...The warming trend continues as 500 mb heights rise some 70 meters from Monday, and with downslope winds helping the warming. Looks like enough low and mid level moisture for isolated late day showers and thunderstorms, limited in coverage by the warm temperatures aloft. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 504 PM MDT Tue Jun 18 2019 Convection ongoing this afternoon across much of southeast Wyoming and Nebraska Panhandle. Greatest concentration over the Panhandle at this time. Look for a decrease in coverage after sunset. SOme low clouds again expected out near the Panhandle overnight...but latest HRRR and SREF output showing lower clouds to east. Makes sense with the westerly downsloping did not go to far on IFR/LIFR conditions tonight. Will continue to monitor this evening. && .FIRE WEATHER... Issued at 110 PM MDT Tue Jun 18 2019 Minimal concerns through the next week. Somewhat lower humidities Wednesday and Thursday afternoons, then higher humidities for Friday through the weekend, then lower humidities on Monday and Tuesday. && .HYDROLOGY... Issued at 110 PM MDT Tue Jun 18 2019 Overall not much change is expected in the flood situation through the next several days. Precipitation chances will remain likely for the area through Today. A brief break with drier weather is expected Wednesday and Thursday before wet conditions return this weekend and next week. High volume flows are expected to continue at Saratoga and other area rivers and streams. A continued wet and active period will continue to pose a hydro threat through the extended. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...RUBIN LONG TERM...RUBIN AVIATION...GCC FIRE WEATHER...RUBIN HYDROLOGY...RUBIN
Area Forecast Discussion
National Weather Service Dodge City KS
552 PM CDT Tue Jun 18 2019 .UPDATE... Issued at 552 PM CDT Tue Jun 18 2019 Cancelled tornado watch for Ford, Clark, Hodgeman and Pawnee counties. Remaining storm near Kinsley is dissipating, with outflow/composite weak front south of Dodge City. Severe weather is in progress across SE Colorado and the northern panhandles, and the expectation is some of this activity should enter SW Kansas this evening. HRRR has strong to severe storms in far SW Kansas around 9 pm. Will keep pops relatively high overnight for this expected additional round of convection. && .SHORT TERM...(This afternoon through Wednesday) Issued at 1142 AM CDT Tue Jun 18 2019 We continue to monitor the possibility of two rounds of storms...the first round this afternoon mainly for areas from the I-70 corridor to the Pratt and Medicine Lodge areas which could have straight line winds, brief QLCS tornadoes, and flash flooding. The second round will come in from eastern Colorado this evening and move across southwest Kansas through midnight. At the time of writing this discussion a mesoscale convective vortex continues in north central Kansas with a stationary front located roughly from Hays to Lamar, CO. CAPE values are continuing to increase south of the front with already MUCAPE values approaching 2000 in spots. CAM models are all in pretty good agreement that the convective mode with the storms will be a QLCS line and less likely a discrete supercell will last more than an hour. Weak bulk shear values from 0-10 km should promote quick upscale growth of storms. 0-3 km shear vectors look to be out of the southwest at 30 kts which could promote a few QLCS tornadoes in the line especially where the line bows back to the northwest along with a straight line wind threat. PW values in the 1.5-1.75" range suggest these storms will be quite water loaded so that along with the weak bulk shear suggest that hail will not be a great threat with these storms. Flash flooding certainly will be since we already have some reports of minor street flooding in Pawnee county from the morning convection and a slight risk of flash flooding from the WPC. Indications are the initial QLCS line will move out of our area around 01-02Z and then the attention turns to the convection which will develop in the front range of the Rockies and move into western Kansas. If this area from Dodge City on west is relatively untouched by the afternoon convection the evening convection should have still an area of 1500-2000 CAPE to work with which will provide a straight line wind risk along with more localized heavy rain. The line of convection should move at a pretty good clip so that by early Wednesday morning we should be done with the storms and left with a quieter day. Wednesday a high moves in behind the convective complex and we should see clearing skies through the morning. There remains a slight chance of some pop up storms in the afternoon mainly west of Highway 83 with another slight shortwave moving in from the northwest upper level flow pattern we will have. .LONG TERM...(Wednesday night through Tuesday) Issued at 1256 PM CDT Tue Jun 18 2019 Thursday into Friday could be a couple of the hottest days of the season upcoming as the upper flow and low level winds will be out of the southwest as GFS and Euro are indicating 850 mb temperatures will be in the upper 20 (C) range. Dewpoints will be in the mid to upper 60s on Thursday with highs in the lower 90s. Then the air should be drier on Friday which will allow highs to make it into the mid 90s. A strong cold front with a upper level trough should come in through Saturday morning which could provide some storms along the I-70 corridor. Temperatures should fall back into the 80s. Long term models introduce another round of front range storms moving through western Kansas from Saturday night into Sunday as an upper level trough moves through. At this point it does look like a couple of dry days to start early next week as the trough exits and the upper level pattern turns more zonal. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 440 PM CDT Tue Jun 18 2019 Winds will trend light N/NW this evening and tonight as a weak frontal boundary sags through SW Kansas. Initial convection has avoided the terminals this afternoon. Additional thunderstorms are expected to arrive from Colorado this evening, with the HRRR/18z NAM forecasting convection along the CO/KS border 00-01z Wed. Included convective TEMPO groups at GCK, LBL and DDC for this expected activity (03-06z) as it progresses east this evening. Consensus of short term models shows post-frontal IFR stratus cigs developing through 12z Wed, with the highest confidence/lowest ceilings at HYS. MVFR stratus may evolve as far south as DDC Wednesday morning with NW winds of 10-20 kts. && .PRELIMINARY POINT TEMPS/POPS... DDC 60 79 65 90 / 90 10 10 10 GCK 57 82 64 90 / 80 10 20 0 EHA 55 81 61 91 / 40 10 0 0 LBL 56 80 65 91 / 40 10 10 0 HYS 60 77 64 87 / 30 10 0 10 P28 64 81 66 90 / 70 10 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Turner SHORT TERM...Tatro LONG TERM...Tatro AVIATION...Turner
Area Forecast Discussion
National Weather Service Des Moines IA
633 PM CDT Tue Jun 18 2019 ...Updated for 00z Aviation Discussion... .SHORT TERM.../Tonight through Wednesday Night/ Issued at 319 PM CDT Tue Jun 18 2019 Confidence: Medium Main challenge continues to be the MCV over northeast Kansas and the track tonight into Wednesday. Models have been tracking the system mainly to the east with the heavier precipitation expected to remain south of the forecast area. Weak trough over the south will likely be the focus of additional showers/thunderstorms this afternoon and evening as some mechanical forcing from the MCV combines with the boundary. The high res models are somewhat divergent on the track of the MCV overnight with the NMM farther north than the ARW with the HRRR not tracking the system very well at this time. Current trends suggest that the track may be a bit farther north. With that in mind, have boosted PoP and rainfall amounts over the south during the late overnight and into Wednesday morning. Across the weak boundary, precipitable water values remain in the 1 to 1.5 overnight into Wednesday morning. Warm cloud depths continue to reach about 9500 to 11000 feet over the south third of the forecast area this afternoon and tonight. This may again result in some locally heavy downpours with brief heavy rainfall in some of the heavier storms. Though overall rainfall amounts should range from 0.25 to 1.25 in the southern third, local amounts may again approach 2 to 2.5 inches in some of the heavier storms. Though widespread water issues are not expected, there may again be some localized urban runoff that may impact streets due to the slower movement of some of the showers and thunderstorms this afternoon. Will maintain higher pops and qpf over the south tonight into early Wednesday as the MCV tracks across Missouri. Lows tonight should hold in the lower 60s south and in the lower to mid 50s over the north. Similar to previous nights, some patchy fog may also occur over the region. For tomorrow, highs will be held down over the south with generally thick cloud cover and showers and storms in the area. Have cut back highs into the lower 70s south and left the north in the mid 70s for the afternoon hours. The system will pull east of the region Wednesday night and with some clearing, fog is going to be more likely over the region; especially in the south where more rain is expected tonight through Wednesday. Lows Wednesday night will fall into the mid 50s to around 60 south. .LONG TERM.../Thursday through Tuesday/ Issued at 319 PM CDT Tue Jun 18 2019 Confidence: Low to Medium Though the early portion of the extended forecast looks similar to previous forecasts, as the weekend rolls around some changes are beginning to show up in the medium range models and this is lowering day to day confidence on details of the forecast at this time. Overall, the transition to southwest flow is still intact with instability increasing by Friday and wind fields strengthening as well. First off for Thursday, a northern stream shortwave will swing northeast with a warm front moving back north through Iowa with warm air advection and chances for showers and thunderstorms Thursday. Highs Thursday will be similar to the past milder days with upper 70s south and mid 70s over the north where rain chances will be higher. By Thursday night into Friday morning, both the GFS/Euro are now initiating an MCS along a new resurgence of thetae advection into Iowa, though at this time the spread of solutions lowers confidence on whether southern/central Iowa would be more favored for the track of the mesoscale system into Friday afternoon. With precipitable water values in the 1.50 to 1.75 inch range, rainfall amounts with any system tracking across the region could drop another 1 to 2 inches of rainfall. In fact, through much of the weekend now, values remain in the 1 to nearly 2 inch category from time to time across the region. With the southwest flow aloft in place from Friday through Sunday, several pieces of shortwave energy continue to track northeast over the area during the period. Each of the waves has the potential to bring repeated rounds of storms into Sunday night. With this change to a extended period of more active weather, the threat for hydro issues could increase along with chances for stronger to severe storms. There is some consensus that by Tuesday, quieter weather will return for a brief time. Highs during the period from Friday into Sunday will daily remain highly dependent on convective trends, but should range from the upper 70s to mid 80s on average; with lows in the 60s to lower 70s with more summerlike humidity expected through the period. && .AVIATION.../For the 00Z TAFS through 00Z Wednesday evening/ Issued at 633 PM CDT Tue Jun 18 2019 Primarily showers over southwest Iowa have been slowly moving into south central and central late this afternoon and will continue to do so this evening. High confidence this will impact DSM and OTM this evening and overnight and lower confidence with just VC wording at ALO. Patchy fog development into MVFR is possible as well over the southern terminals. Showers and MVFR ceilings will linger over southern Iowa on Wednesday with gradual improvement into VFR at DSM and perhaps near the end of this TAF period at ALO. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...REV LONG TERM...REV AVIATION...Ansorge
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1005 PM CDT Tue Jun 18 2019 .UPDATE... Quick update to adjust PoPs based on the current radar trends and the newest evening high resolution models. Convection from West Texas moved right along the Crockett/Val Verde then Sutton/Edwards County lines before weakening. Outflow from these earlier storms is currently moving to the southeast from Brackettville to Reagan Wells to Leakey to Mountain Home and has sparked off a few isolated showers and storms near Barksdale. These isolated storms should continue for a few more hours before dissipating as the outflow continues to outrun any convection it sparks off. Newest high resolution guidance keeps the storms across north Texas well to the north of the area tonight, so PoPs have been trimmed back after midnight to just included the possibility of a few more isolated showers/storms along the outflow west of I-35. Areas east of I-35 should be dry overnight. There is a low chance of some patchy fog by morning, but with a bit higher winds tonight and not as much precipitation during the day compared to yesterday coverage should be less than what was seen this morning. For this reason have continued to leave mention out of the grids. && .PREV DISCUSSION... /ISSUED 646 PM CDT Tue Jun 18 2019/ AVIATION... ISOLD-SCT SHRA/TSRA currently over the Pecos Valley to the Big Bend to Davis Mountains areas will move toward the east over the Edwards Plateau this evening, then gradually dissipate over the Hill Country later this evening, possibly Central Texas overnight. Have mentioned VCSH for KDRT where the best chances are. Will monitor trends for possible updates for TSRA at KDRT this evening and SHRA/TSRA at KAUS overnight. For KDRT, SHRA/TSRA over the Edwards Plateau will bring low end VFR CIGs and VRBL winds around 5 KTs, possible gusts to 25 KTs, this evening, then SE winds 5 to 10 KTs return with VFR skies prevailing Wednesday. At KSAT/KSSF/KAUS, VFR skies prevail this evening with S winds 5 to 10 KTs. IFR CIGs develop overnight, then rise to MVFR as low level jet strengthens. CIGs mix out to FEW-SCT VFR clouds with S winds 10 to 15 KTs with occasional gusts to 25 KTs on Wednesday. PREV DISCUSSION... /ISSUED 301 PM CDT Tue Jun 18 2019/ SHORT TERM (Tonight through Wednesday Night)... Despite the presence of broad, mid to upper level ridging across the southern half of Texas today, a gravity wave from overnight convection across the Permian Basin and Low Rolling Plains allowed for a thunderstorm complex to propagate into the Brazos Valley earlier today. Remnants of an outflow boundary associated with these storms were evident on visible satellite imagery along a Mason/Dripping Springs/Giddings line early this afternoon and will be watching for isolated late afternoon shower development along this feature as it lingers across the region. Anvil debris slowed modification of the post-boundary airmass earlier today (allowing for the boundary to linger and drive farther to the south and east), but clearing skies have allowed for temperatures behind the boundary to spring back into the mid 80s and additional insolation should allow for this boundary to wash out by this evening. Farther to the west, a 50-70 knot upper level speed maxima straddling the Big Bend was allowing for isolated to scattered showers to linger across Val Verde County. This has produced persistent scattered cloud debris across the southern half of the county and has limited overall convective intensity today. With little overall change in the pattern across the state, expect similar storm trends tonight with some of the activity across the Davis Mountains and Big Bend making a run for Val Verde this evening. The aforementioned stability will likely limit how far east these storms are able to make it, but will also be watching areas farther north tonight where a surface trough across the Low Rolling Plains may serve as a focus for another nocturnal thunderstorm complex that makes a run for the region. Higher resolution guidance like the HRRR and NSSL-WRF try to keep this complex north of the region and take it into North Texas, but Corfidi vectors are oriented more northwesterly and indicate that portions of Central Texas may again be clipped by a morning complex should it hold together. (Corfidi vectors can be used to anticipate surface based mesoscale convective systems based on the strength/direction of the low level jet, orientation of cold pool relative flow, as well as instability present ahead of the system.) Have added some low rain chances (20/10 PoPs) to Central Texas for the early morning and morning hours to account for this potential. Otherwise, expect another warm night for the region with lows in the 70s. Have held off on including a patchy fog mention at this time with at least a weak low level jet in place tonight, but areas east of a Fredericksburg to Gonzales line will need to be monitored for potential fog development. Ridging becomes more zonal on Wednesday as a shortwave drops into the Southern Plains from Colorado and this will help veer 850-700 MB flow, resulting in temperatures skyrocketing to the mid 90s to low 100s across the region by Wednesday afternoon. Only modest mixing during the afternoon hours will mean hot and humid conditions produce heat index values in the 102 to 110 degree range and a Heat Advisory may be needed for areas east of Interstate 35. Associated capping from this veered low-mid level flow should limit overall rain chances but will need to watch what appears to be a weak cold front (or possible outflow from storms over Oklahoma tonight) sliding into West Central Texas for possible shower or thunderstorm development. Little relief from the heat is expected Wednesday night with lows in the mid 70s to lower 80s. LONG TERM (Thursday through Tuesday)... Zonal flow aloft persists through Thursday, but becomes southwesterly and amplifies Friday and Saturday as longwave troughing becomes established across the western CONUS. The thermal ridge associated with the veered low level flow appears to be the strongest on Thursday and have maintained advertising widespread 100-105 degree temperatures. A Heat Advisory is also possible again on Thursday. As upper level flow becomes more southwesterly, this will help back lower level flow, moderating high temperatures a few degrees (highs in the mid 90s this weekend as opposed to the ground scorching 100+ during the mid- week period) and allow for isolated to scattered thunderstorm changes to enter into the forecast as embedded disturbances in the flow aloft translate near the region. As the upper trough axis begins to slide east early next week, rain chances look to translate east of the region sometime around or after Tuesday. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 77 98 77 100 77 / 10 10 - 0 0 Austin Bergstrom Intl Airport 76 98 77 100 77 / 10 10 - 0 0 New Braunfels Muni Airport 75 99 76 101 75 / 10 10 - 0 0 Burnet Muni Airport 75 97 76 99 75 / 20 10 - 0 - Del Rio Intl Airport 77 100 77 104 77 / 20 10 10 0 - Georgetown Muni Airport 75 98 77 100 76 / 10 10 - 0 0 Hondo Muni Airport 76 102 77 104 76 / 10 10 - 0 - San Marcos Muni Airport 75 99 76 101 76 / 10 10 - 0 0 La Grange - Fayette Regional 77 98 78 99 78 / 10 10 - - 0 San Antonio Intl Airport 76 100 77 102 77 / 10 10 - 0 0 Stinson Muni Airport 77 100 78 103 77 / 10 10 - 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Aviation...04 Short-Term/Long-Term...Treadway
Area Forecast Discussion
National Weather Service Key West FL
1027 PM EDT Tue Jun 18 2019 .DISCUSSION... Have watched two separate outflow boundaries this evening. The first moved off the South Florida Peninsula and across the Upper Keys early this evening, with Carysfort Reef Light gusting to 30 mph. The second outflow originated from convection near Varadero, Cuba, and raced north across the Straits. It appeared to weaken just before reaching the islands. The 00z KEY sounding showed some convective inhibition developing, but it still appears breakable given sufficient low- level focus. The PW value still exceeded 2" which indicated a tropically moist air mass. The question is how much convective activity will flare up during the overnight and early morning hours along these leftover boundaries. The last 2 runs of the experimental Caribbean HRRR have both picked up on the Cuban-borne outflow. They then focus new convection overnight somewhere between Key West and the Dry Tortugas, with the possibility of showers and thunderstorms brushing the Lower Keys in the hours around sunrise. In reality, showers could develop most anywhere. By mid-day Wed, the strengthening of the subtropical ridge over South Florida and building 500 mb heights over the Keys will start a larger-scale drying of the mid-level air mass. The coverage of showers and thunderstorms should diminish substantially and remain below climatology for the rest of this week and this weekend. && .MARINE... A subtropical surface ridge will strengthen over South Florida and persist through this weekend. As a result, gentle to moderate east- southeast breezes will prevail. && .AVIATION... VFR conditions will prevail at both terminals. Previous showers and thunderstorms over the Florida peninsula have left an inactive boundary just north of the Lower and Middle Keys. Meanwhile, another boundary is moving north across the Straits of Florida and will likely interact with the northern boundary creating potential for at least VCSH at either or both terminals before midnight tonight. Temporary MVFR ceilings may need to be part of an amendment. Gusts near 25 knots are possible should showers or even thunderstorms become more certain to affect the terminals. Pesky mid-level ceilings between FL160 and FL220 will continue throughout the period. Winds will remain southeast to south near 10 knots, outside of any possible convective activity. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...Haner Aviation/Nowcasts....Chesser Data Collection......SD Visit us on the web at Follow us on Facebook and Twitter at:
Area Forecast Discussion
National Weather Service Marquette MI
752 PM EDT Tue Jun 18 2019 .SHORT TERM...(This evening through Wednesday) Issued at 452 PM EDT TUE JUN 18 2019 Water vapor imagery and RAP analysis show a mid-level low over Quebec with troffing extending sw into the Northern Plains and northern Great Lakes. Within the trof, shortwave has moved e from MN into western Upper MI today with associated cold front over central Upper MI. Ahead of this feature, there has been enough daytime heating to boost sbcape to 500-1000j/kg into s central Upper MI per latest SPC mesoanalysis. As a result, shra and isold tsra have developed. With deep layer shear of 40-50kt, a strong storm or two will be possible for the next hr or so. To the w, there has been nothing more than a few sprinkles today. Ongoing shra/isold tsra will diminish/end over the next several hrs as shortwave/cold front continue moving e. There are some shra back to the w over ne MN, but with these shra largely a result of daytime heating, these shra will not be able to move out across Lake Superior. Thus, don`t expect any additional shra after the ongoing activity over the e half of the fcst area ends. Vis satellite imagery showed a few patches of fog on Lake Superior earlier today, but not really seeing much now, though clouds are obscuring the view over portions of the lake. If there are some fog patches out there yet, light n to nw winds into the n central/ne fcst area would result in fog/stratus developing in those areas during the night. Will be something to monitor. Even without that, there could be some patchy fog development anywhere tonight, especially where rain occurred today. However, with fcst soundings showing relatively moist air mass thru a fairly deep sfc based layer, not sure there will be much. Expect min temps mostly in the 40s across the board. A shortwave now over ND will move across the area on Wed. Wave looks fairly well-defined now, but is not producing much in the way of shra. With fcst soundings suggesting a cap here on Wed, not expecting any -shra development. Depending on low cloud development tonight, there may be quite a bit of cloudiness in the morning, but trend will be for increasing sun as moisture mixes out Wed. Temps will respond into the lower 70s in the interior. Onshore winds near Lake Supeiror will keep conditions cool along the lake, especially e of Marquette. Temps not likely to get above the 50s lakeside. .LONG TERM...(Wednesday night through Tuesday) Issued at 331 PM EDT TUE JUN 18 2019 Through the end of the work week, the large scale upper air pattern will continue to consist of a closed low over Quebec and another over southern British Columbia that will gradually shift eastward. This will lead to western CONUS troughing and central CONUS zonal flow amplifying into ridging over our region Thursday night through Friday. An impulse ahead of the main trough will bring scattered showers and perhaps a few thunderstorms to the region over the weekend, though better chances for heavier rain currently look to stay to our south in WI. The trough will be slow to progress eastward and is currently progged to cross Upper Michigan sometime Monday, with ample uncertainty remaining in the exact timing and strength of forcing as it crosses. In general, trends have been towards a slower progression through this weekend into early next week. Upper level flow becomes more northwesterly into midweek which should lead to mostly dry conditions once again, but shortwave activity may bring additional scattered shower/isolated t-storm chances. As a Hudson Bay high extends sfc ridging through the western Great Lakes Thursday into Friday, dry weather will prevail with seasonal temperatures, though remaining a tad cooler than normal near Lake Superior. Some chances for fog, mainly over the west and western Lake Superior are possible Wednesday night into early Thursday. Warm, moist air will trickle in through Friday with just a slight chance for a shower over the west late. Then moisture transport looks to increase in earnest Saturday as low level flow becomes more southerly. Mostly cloudy skies will keep temperatures a tad cooler Saturday as rain chances increase. Thunderstorms will be possible in the Saturday afternoon-Sunday night time frame. Uncertainty remains through this time with some indications of CAPE exceeding 2500-3000 J/kg Sunday afternoon over central Upper Michigan (GFS) and other models bringing little if any instability into the region (00Z EC, 12Z CMC-NH). Regardless, PWAT values look to rise to near 1.5 inches through much of the weekend, and heavy rainfall will be possible. Chances for stronger storms will have to be monitored as the mesoscale environment becomes more clear. On the whole, better chances for widespread precipitation will probably come after 00Z Sunday as better WAA moves in and ridging exits further east, but this is not reflected in the NBM POPs. GFS/ECMWF are now locked in pretty well on main trough passage coming Monday afternoon with widespread rain. Ensembles seem to support this idea, but given the anticendent blocking pattern there does remain some wiggle room in timing and ensemble plumes indicate a large spread in intensity/QPF. At this time, thunder chances are low with this, but plenty of time for that to change as well. After the trough finally passes, generally dry conditions would be expected into the middle of next week with somewhat cooler temps expected to briefly impact the region. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 752 PM EDT TUE JUN 18 2019 This evening will continue with VFR conditions at all terminals, however overnight, there is potential of stratus and patchy fog developing. Confidence has increased, but is still low with this forecast issuance. Expect some MVFR and IVR cigs at SAW while CMX will border VFR/MVFR cigs and IWD will drop into MVFR cigs overnight. Although SAW is expected to fall into IFR conditions, there is a possibility to fall into LIFR conditions briefly. Should fog develop and linger, expect mainly IFR vsbys with an slight chance for LIFR vsbys. Conditions at all terminals are expected to improve to VFR a few hours after sunrise. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 452 PM EDT TUE JUN 18 2019 Sfc high pres will prevail across Lake Superior thru Thu, keeping winds under 20kt, but for much of Lake Superior, winds will be under 15kt. Winds will increase Fri thru the weekend as a cold front approaches. Wouldn`t be surprised to see winds in the 15-25kt range at times. There may be some patchy fog on Lake Superior tonight into Wed night, but if it doesn`t develop tonight, fog won`t be an issue Wed or Wed night. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...KCW AVIATION...JAW MARINE...Rolfson