Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/14/18

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
541 PM MDT Mon Aug 13 2018 .AVIATION... 00Z TAF CYCLE Storms generally moving from north to south late this afternoon/early evening before gradually dissipating prior to 14/06Z. Brief MVFR cigs/vsbys along with small hail and wind gusts to around 40kt possible with the stronger storms. Convection is forecast to diminish aft 14/06Z. Main change Tuesday will be west winds aloft across the northeast third of the state pushing storms to the east around 15kts. 33 && .PREV DISCUSSION...310 PM MDT Mon Aug 13 2018... .SYNOPSIS... High pressure aloft centered just west of New Mexico will gradually shift eastward through mid-week becoming centered squarely over central sections of the state by Wednesday. At the same time, a weak boundary is expected to sag into northeast New Mexico later Tuesday. This will create a favorable environment for a few strong to briefly severe storms the next few days. Otherwise, thunderstorms that form over and near the higher terrain will slowly move toward the south or southeast through Tuesday before steering winds become even weaker for Wednesday and Thursday. Daytime temperatures will remain a little above normal, especially Wednesday. The upper high should weaken for the latter half of the week allowing for increased shower and thunderstorm coverage especially on Friday and Friday night. Drier air could limit storm coverage by Sunday with the best chances across southern and eastern New Mexico. && .DISCUSSION... Closed low vicinity of the western OK panhandle slowly pivoting eastward but still slower with a deeper/better defined circulation than what the latest models have depicted. Farther west, main upper high center just west of the Four Corners. Resultant north to south steering flow continues over much of the area. Convective parameters across the eastern high plains /MU CAPE 2000-2500 J/kg/ much more favorable going into the rest of the afternoon/evening, especially the northeast where surface dew points have recovered from yesterday`s drying episode. The latest HRRR suggests a few strong to briefly severe storms possible, especially along/just west of the Pecos River Valley from Santa Rosa to Ft Sumner to north of Roswell. Elsewhere, will monitor convection rolling toward the south off the higher terrain with areas along the immediate east slopes, the upper RGV and northwest third, and upper Gila most favored. Models similar showing building 500mb heights over the area Tuesday- Tuesday night as the upper high shifts eastward. This should limit overall coverage a tad except across the northeast where a southward-sagging boundary is expected to bolster storm coverage there beneath a weak northwest flow aloft. Lighter steering winds would keep central/western valleys pretty quiet until late day or evening with outflow boundary interactions key. Mid- to upper- level ridge axis then takes on a NW to SE orientation over New Mexico Wednesday and Wednesday night. This will favor the northeast and southwest quarters of the area for the most vigorous/persistent convection and would not be surprised if a few strong/severe storms cross the the northeast highlands/far northeast plains. We`ll be watching the progress of an inverted trough that may impact far southwest areas of the state and the NAM is quite bullish on QPF vice the GFS/ECMWF. Main focus in the extended periods is the approach of a shortwave trough that translates eastward over the Great Basin Friday and toward the central Rockies Friday night. This will effectively weaken the upper high over our area and force any defined center east/south with enough weakness in the ridge to allow a decent sub-tropical plume to focus northward with some interplay with some weak large- scale forcing for ascent especially northern areas. Drying then indicated the follow with the best storm chances shifting to the east and south by Sunday. KJ && .FIRE WEATHER... No critical fire weather conditions anticipated through the upcoming weekend. Overnight humidity recoveries will generally be good to excellent, but there will be only fair recoveries far northwest New Mexico. Locally fair to poor ventilation central and east Tuesday, with some improvement Wednesday, then areas of poor rates forecast for the west and north Thursday and Friday. With high pressure aloft moving over Arizona and New Mexico, storm motion through tonight will be generally from north to south, except in the northeast where it will be more from northwest to southeast. Showers and storms which fire over the higher terrain will drift down into the lower elevations this evening and into the northeast and east central plains. The storms in the plains will be aided by a frontal/outflow boundary tonight but short term models indicate this activity will diminish after midnight. Tuesday through Wednesday, low level easterly flow will support moisture in the east, while the Rio Grande Valley will experience a burst of east winds during the evenings which helps slosh moisture westward. Therefore, showers and thunderstorms will likely be more widespread Tuesday and Wednesday afternoons and evenings. Storm motion may become slower and more erratic, increasing the potential for heavy rainfall. Highs will be within a few degrees of normal. The upper high center may wobble to the southeast of New Mexico late this week, then re-form and/or strengthen back to our west early next week. A stronger front is forecast to push into eastern New Mexico Sunday night/Monday. Thursday through Saturday look fairly active with scattered to numerous showers and thunderstorms, although drier air may inhibit convection over the far northwest corner. && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$ 41
Area Forecast Discussion
National Weather Service La Crosse WI
616 PM CDT Mon Aug 13 2018 .SHORT TERM...(This evening through Tuesday) Issued at 208 PM CDT Mon Aug 13 2018 Mostly sunny/clear skies to continue through tonight. Introduced patchy valley fog after 14.06Z given clear skies, light winds, and low surface dewpoint depressions. Still some uncertainty with the depth of the light wind layer, but enough similarities to this morning`s set-up to add it to the forecast. Lows tonight will range from the mid 50s to mid 60s. 13.19Z water vapor loop shows two well-defined cut-off lows. The first is across the lower Great Lakes/Ohio River Valley while the second is centered over the CO/NM/OK/TX border region. It is this second low that will drift slowly eastward through Tuesday, although most of its energy will remain south of the forecast area. At the same time, a Canadian trough will pass to the north. Latest guidance suggests little interaction between these two features, thus limiting the deep layer lift necessary for convective development. Will maintain 20 to 30 POPs Tuesday afternoon across much of the area as a weakening cold front moves through, but wouldn`t be surprised if some areas remain dry. For those areas that see rain, amounts will generally be a quarter of an inch or less. Tomorrow will otherwise be another warm day with highs in the mid 80s to near 90 degrees. .LONG TERM...(Tuesday night through Monday) Issued at 208 PM CDT Mon Aug 13 2018 On Tuesday night, the 13.12z models continue to show that the moisture transport and instability will weaken along the cold front north of the Interstate 90 corridor. Meanwhile, further to the south, scattered showers and storms will continue as a weakening short wave moves northeast through the Upper Mississippi River Valley. With the best moisture remaining to our southeast, not anticipating that much rain from this system. Rainfall totals will be up to a quarter of an inch. From Wednesday into Wednesday night, the closed upper level low will slowly transition from eastern Iowa into the Lower Great Lakes. As this occurs, scattered showers and storms will be seen across the region. The highest rain chances will be on Wednesday where some locations may see up to a quarter of an inch. With the Canadian model appearing to be a wet outlier, lowered the QPF for Wednesday night. With less cold air advection into the region, raised the maximum temperatures by a couple of degrees for the high temperatures on Wednesday. From Thursday afternoon through Friday, the models continue to show that a short wave trough will move southeast from the Northern Plains into the Mid Mississippi River Valley. There has been a slight southern shift in the track of this wave. If this trend continues, we may be able to dry out areas north of Interstate 90. For the weekend, the models continue to show some ridging building across the region. 925 mb temperatures respond to this by warming us into the lower 20s. As a result, we should see a return to above- normal temperatures. For early next week, there are still timing issues of a short wave trough moving out of Canada. Since there are no clear indications on which model is correct on its timing, made no changes to the model consolidation. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 616 PM CDT Mon Aug 13 2018 An area of high pressure was centered over northern Illinois late this afternoon and is not expected to move much overnight. With this position of the high, there looks to be the potential for valley fog tonight. Forecast soundings from the 13.18Z NAM and 13.21Z RAP both show a relatively deep layer of light winds from the surface up to four thousand feet or so and with light south winds on the back side of the high, the winds are favorable for fog. Skies should be clear with the only problem being whether saturation will occur at the surface or not. The NAM does show saturation occurring right at the surface with a very dry layer above that while the RAP does not show saturation occurring. For now, will stay with the previous forecast of 3sm at KLSE with some fog and monitor temp/dew point trends through the evening. A cold front will approach from the northwest Tuesday afternoon but the majority of the forcing is expected to stay south of both airports closer to the upper level low that will be moving from Kansas into Missouri. Will include some diurnal cumulus with the front but confidence too low to include any mention of VCSH/VCTS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Rogers LONG TERM...Boyne AVIATION...04
Area Forecast Discussion
National Weather Service Bismarck ND
916 PM CDT Mon Aug 13 2018 .UPDATE... Issued at 916 PM CDT Mon Aug 13 2018 Scattered showers and isolated thunderstorms continued moving east across central North Dakota. Expect northwestern and north central North Dakota to be free of showers after midnight. However, models are still supporting increase in showers and thunderstorms for south central and southeastern North Dakota late this evening and overnight. A weak upper level impulse is forecast to move across southern North Dakota, moving over an area where mixed layer CAPE remains along and behind the cold front (now extended from central Minnesota to near Wahpeton to central South Dakota). Have adjusted hourly precip chances accordingly. Otherwise temperature forecast remains on track. UPDATE Issued at 627 PM CDT Mon Aug 13 2018 Increased coverage of slight/small chances of showers and thundershowers, as latest high res models not really picking up on all of the convective activity. The northeast to southwest oriented showers were oriented behind the cold front, which extended from north central Minnesota to near Fargo to south of Jamestown into a surface low in central South Dakota. The other area of scattered showers and thunderstorms over Williams/McKenzie/Mountrail counties was moving east/northeast, along weak upper level impulses - with initial enhanced lift from the secondary cold front (much cooler air in northern ND with temperatures currently only in the 60s). Global and high res models still indicating some increase in convective activity later this evening and overnight along northern WY/SD and into southeastern ND (and in the James Valley in south central/southeastern ND). Thus increased chances there as well. Otherwise blended current temperatures with expected trends tonight. Still expecting lows tonight ranging from the upper 40s northwest to upper 50s James Valley. && .SHORT TERM...(This evening through Tuesday) Issued at 224 PM CDT Mon Aug 13 2018 Latest radar imagery continues to show post frontal showers and isolated thunderstorms northwest through north central. Surface cold front now into Jamestown, and will linger across the southern James River Valley this evening before stalling over northeastern South Dakota tonight. Weak CAPE north with little or no shear will maintain mostly rain showers and non-severe isolated thunderstorms northwest into north central this afternoon. Post frontal clouds are now shifting into south central North Dakota this afternoon, and there is a slight chance of a shower late this afternoon/early evening. However, there is a better chance for showers/thunderstorms to redevelop later this evening/tonight across the James River Valley. The CAMS`s have been consistent with this idea since this morning, in developing an area of shower and thunderstorms between 04z and 10z Tuesday. Frontogenetical forcing with decent lapse rates and large scale ascent per NAM/GFS will set the stage for precipitation development. Although some strong thunderstorms are possible, not expecting severe weather at this time. Most Unstable/MU CAPE per NAM ranging between 250 and 750 J/KG and deep layer shear 35kt to 40kt. The GFS has similar deep layer shear, but no CAPE advertised,as it is shunted south and east of the border, in closer proximity of the stalled front. Smoky skies have shown improvement in the west this afternoon per latest satellite imagery and surface observations. Upstream observations into Canada also have improved. The vertically integrated smoke forecast per HRRR shows lingering patchy smoke mainly southern ND Tuesday. Thus, have scaled back the areas of smoke north and west in the short term period. Cooler air finally slides from north to south overnight along with an area of stratus clouds The stratus per HRRR/GFS will push into the Turtle Mountains and portions of north central ND late tonight through mid morning Tuesday. Plenty of sunshine anticipated elsewhere for Tuesday with highs in the 70s Tuesday across western/central ND. .LONG TERM...(Tuesday night through Monday) Issued at 224 PM CDT Mon Aug 13 2018 Warming in the early part of the long term period with highs rising into the 80s Wednesday and then upper 80s to lower 90s Thursday and Friday. Cooler air is expected Sunday and Monday. As far as precipitation, a shortwave emerging over the Northern Rockies will slide into southeastern Montana Tuesday night, then across South Dakota Wednesday. Far southwestern and far south central ND remain on the fringes of a slight chance of showers and thunderstorms. The ECMWF maintains a stronger signature of PoPs across the southwest and extends them into western ND Wednesday. Did not adjust from Forecast Builder at this time which yielded the initial solution above and goes along with the NAM/GFS solutions. Otherwise, it remains dry over the rest of western/central ND Tuesday night through most of Saturday. For Sunday, differences arise on the track of our next Northern Rockies shortwave. The GFS moves it through North Dakota with chances for showers and thunderstorms across western/central ND Sunday; while the ECMWF maintains a track from southeastern Montana and into South Dakota, which advertises less precipitation Sunday. Behind the system Monday, both models show cooler air via northwest flow. The CIPS analog also advertises a brief cooling trend late this weekend into early next week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 627 PM CDT Mon Aug 13 2018 Visibilities have improved from smoke across western and central North Dakota and will not have reduced vsbys this TAF cycle. Otherwise, will keep VCSH or VCTS early this evening at KMOT/KBIS with ongoing convection moving east across the state. Later this evening will have VCTS at KJMS with expected new development of showers and thunderstorms mainly from around 03z-10z. An area of stratus/mvfr cigs moving south out of Canada is possible at KMOT from around 11z-16z Wednesday...and will keep a sct deck mentioned for now - later forecasts may determine whether that stratus deck makes it to KMOT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JV SHORT TERM...KS LONG TERM...KS AVIATION...JV
Area Forecast Discussion
National Weather Service Denver/Boulder CO
914 PM MDT Mon Aug 13 2018 .UPDATE... Issued at 910 PM MDT Mon Aug 13 2018 The following are changes made to the 1st period forecast grids. First, have trended dew points on the plains upward overnight. Since 00z, dew points at several reporting site east of a Greeley- to-Elbert Line have risen 6-10 deg F. It`s possible we could see some fog forming late in the far eastern zones. This rise in dew point corresponds to a strengthening east-southeast low-level flow. In the past hour, gusts as high as 25 kts have been observed. This influx of moisture is expected to slow cooling, and therefore I`ve nudged up min temps on the plains by at least a deg or two. Lastly, the narrow north-south band of showers/ t-storms passing over south-central WY at the moment coincides with a weak mid-level shortwave trough. At its present speed, could see this wave and its poorly organized convection tracking across the northeast corner of the CWA between 06z and 10z tonight. Therefore, have added a slight chance of showers/t-storms for this area later tonight. && .SHORT TERM...(This evening through Tuesday) Issued at 204 PM MDT Mon Aug 13 2018 A mid to upper level low, which is currently over the Oklahoma panhandle, will begin to move northeastward tonight and tomorrow ending its influence on the weather in Colorado. Behind it, an upper level ridge will build over Colorado tonight which will allow for a quiet night with any showers and storms ending in the evening. Low temperatures will be near normal with mostly clear skies. Mid to upper level winds will turn northwesterly tomorrow as a small shortwave trough will influence the CWA during the afternoon. Ascent from this feature combined with increased moisture and weak upslope winds will allow for a better chance of showers and storms mainly over the mountains and urban corridor. Mixed layer CAPE values will be around 1000 J/kg and 0-6km bulk shear will be around 30 knots so the severe weather threat will remain minimal. Nonetheless, a storm or two could produce severe hail near the Cheyenne Ridge and storms elsewhere could produce gusty winds up to 50 mph. The HRRR smoke model indicates that the smoke will be near or above the thickness we saw today. This may lower the amount of instability compared to what is predicted furthermore limiting the severe threat. High temperatures will be roughly 5 degrees cooler than today with cooler temperatures at the low levels advecting in from the east. .LONG TERM...(Tuesday night through Monday) Issued at 204 PM MDT Mon Aug 13 2018 For Tuesday night into Wednesday the central ridge of high pressure will be over the Great Basin. This will help to increase NW flow over the northern CO ahead of an upper vort max near S. Dakota late Tuesday. Storms will slowly dissipate over the higher terrain into the evening hours and with modest NE mid-level flow out to the east and southerly flow closer to the foothills will keep any convection mainly pinned to the mountains and northern foothills. By Wednesday afternoon a mid-level jet forms over the far NE plains in accordance with the vort max that will drop SE into western NE and could clip the far NE corner of the state. Specific humidity values in the 700- 500 mb range will increase slightly with model soundings showing PW values moving above an inch on the GFS. Models show a convergence boundary setting up over the far eastern plains as a surface low develops over WY and pushes into CO butting up against SSE flow over the southern and eastern plains. This northerly push could help to keep storms out of the Denver Metro and over the mountains and Palmer divide into the late afternoon then along the boundary in the evening where the better instability and deep shear is forming. Flow aloft will be decent so flooding threat is low for Wednesday. Highs will continue to be slightly above average with temps in the upper 80s to lower 90s on the plains. For Thursday and Friday several ridges will span the southern CONUS reaching from the CA coast to the Gulf of Mexico coast. Models are showing moisture increasing in the mid levels with hints of the monsoonal moisture plume trying to resurface. Specific humidity values will increase into Friday with model PWs climbing to well above an inch by Friday afternoon. There will be a chance of storms over the higher terrain Thursday with temperatures very similar to Wednesday. However, on Friday, the upper ridge will be far enough east and west to allow for increased moisture intrusion and greater storm coverage into late Friday. Flow aloft will decrease introducing slower storm motion and the potential for some flooding with the stronger cells. Temperatures will be slightly cooler Friday with highs in the upper 80s. For the weekend, upper level NW flow will increase with an approaching wave. PW values will remain high over the region with increased chances of storms over the plains bringing moderate to heavy rain and hail Saturday and Sunday. Temperatures will be cooler starting Sunday and into next week with a cold front and upper trough possible by Monday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 910 PM MDT Mon Aug 13 2018 VFR conditions are likely at Denver area air terminals for the remainder of the night. However, lingering smoke emanating from several large western fires will probably continue to impact arrival rates. East-northeast winds of 7-14kts will gradually turn southeasterly, then southerly after 07z tonight and remain about the same speeds. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Baker SHORT TERM...Danielson LONG TERM...Bowen AVIATION...Baker
Area Forecast Discussion...Updated
National Weather Service Billings MT
938 PM MDT Mon Aug 13 2018 .UPDATE... Upper trof to the NW will slowly make its way SE overnight and into Tuesday. Associated jet and upper dynamics will increase over our southern and eastern sections overnight. This is playing out a little slower initially than some models had progged, but things are picking up quickly as we head into the mid to late evening with coverage of precip expanding out of the foothills. Adjusted PoP`s for the current trend toward this solution. Rest of forecast in good shape. BT && .SHORT TERM...valid for Tue and Wed... Right-rear quadrant of upper jet will remain over the area tonight, before shifting S of the area on Tuesday. A strong shortwave will rotate into the western zones by 00Z Wednesday, and move slowly E through the area on Wednesday. Upper ridging will build over the region behind the wave through Wed. night. Precipitable waters will be close to an inch over much of the area through Tue. evening. Upslope flow will help convection initiate off the mountains through this evening and again on Tuesday. The dynamics and moisture mentioned above will also support precipitation. RAP soundings showed possible strong storms W of KBIL and around KSHR into this evening. On Tuesday, MLCAPES were progged to be at least 1000 j/kg and shear was favorable over KSHR and far S. Central MT, so this area was placed in a Marginal Risk for severe storms. Will issue an HWO for this as well as a graphic. Will have scattered convection across the area tonight into Tue., then another round of convection Tue. afternoon into Tue. evening shifting into the SE. Isolated convection will linger over the SE Wed. morning, then the rest of the period will be dry. Not seeing much letup in the smoke through the period based on W to NW winds advecting in smoke from the large fires W and NW of the region. Kept temperatures the same with highs in the low 80s on Tue. and in the low 90s on Wednesday. Arthur .LONG TERM...valid for Thu...Fri...Sat...Sun...Mon... Shortwave ridging over the area on Thursday will bring mainly dry conditions outside of some isolated showers and thunderstorms over the mountains, and above normal temperatures. Models continue to prog an upper trough moving through the Pac NW and into the Northern Rockies over the weekend into early next week, with an associated low developing over the region. While the general solution is agreed upon, models differ on the placement and track of the upper low. The GFS takes the low across central Montana, while the ECMWF takes the low across northern Wyoming. The GFS is currently the wetter of the two solutions. Regardless, shower and thunderstorm chances look to increase through the weekend with cooler temperatures over the area. Highs look to range from mainly the 90s on Thursday and Friday, cooling into the upper 70s to lower 80s for Saturday, Sunday, and Monday. Low temperatures look to range from the 50s and 60s Thursday night and Friday night, with lows mainly in the 50s through the rest of the long term. STP && .AVIATION... Isolated showers and thunderstorms will spread eastward along the mountains/foothills and nearby areas this evening, increasing in coverage as they move onto the plains overnight. Local MVFR conditions are possible under the heaviest showers/thunderstorms. Areas of smoke will continue to restrict visibility between 5 and 10sm at times, particularly impacting slant range visibilities. Otherwise VFR conditions will prevail. BT && .PRELIMINARY POINT TEMP/POPS... Tue Wed Thu Fri Sat Sun Mon ----------------------------------------------------------- BIL 057/081 058/091 059/093 062/090 061/082 057/078 055/079 33/T 10/K 01/U 12/T 23/T 43/T 22/T LVM 049/083 048/091 050/091 052/087 052/079 050/077 049/078 12/T 10/K 11/B 12/T 35/T 53/T 23/T HDN 057/083 055/092 057/094 059/093 059/083 055/080 054/081 44/T 10/K 00/U 12/T 23/T 44/T 23/T MLS 058/083 059/089 061/095 063/096 062/088 058/081 055/081 21/H 11/K 00/U 01/B 13/T 43/T 12/W 4BQ 058/083 056/088 057/094 060/094 060/087 055/080 055/082 45/T 51/K 00/U 11/B 14/T 45/T 22/W BHK 054/081 055/087 057/093 058/093 058/087 054/079 052/081 21/H 11/K 11/U 01/U 12/T 45/T 22/W SHR 054/082 053/088 054/091 056/089 056/082 053/078 052/080 33/T 41/K 11/U 12/T 23/T 54/T 23/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$
Area Forecast Discussion
National Weather Service Dodge City KS
925 PM CDT Mon Aug 13 2018 .SYNOPSIS... Issued at 251 PM CDT Mon Aug 13 2018 Upper level low pressure will continue to wobble northeastward across the central plains through Tuesday. Very moist low level air had advected into central and southwestern Kansas and soundings were moist through a deep layer on up through 500mb and beyond. In the wake of this system, a weak cold front is expected to pass across western Kansas, with a wind shift to the north. Another upper level system will pass southeastward across the upper Midwest by Thursday, helping to push another weak cold front into western Kansas by Thursday night. Over the weekend, a stronger upper level system over the Pacific Northwest is expected to move southeastward and approach the plains on Saturday. This feature should pass across Kansas by Sunday and Sunday night along with another cold front. By early next week, an upper level ridge will develop across the southern Rockies and western high plains, with a deep upper level system over the Great Lakes. In between these features, cool surface high pressure ought to settle across the high plains region. && .UPDATE... Issued at 925 PM CDT Mon Aug 13 2018 Initial round of convection has tapered off to largely stratiform rain across much of the CWA at of 9:15 pm. The composite outflow boundary of this evening`s thunderstorms has pressed through most of SW KS, initiating new convective updrafts as it has progressed. The flooding threat has abated, but it may very well be temporary. 00z NAM, HRRR and various other CAMs are showing a strong signal for strong thunderstorm redevelopment overnight, starting around midnight and continuing well into Tuesday morning. 00z NAM deepens the closed low to near 580 dm near Hays by 7 am, with vort maxima swinging around its backside expected to dynamically force more convection, despite depleted surface based CAPE. We are concerned about a threat for flooding during the midnight - 10 AM Tuesday timeframe, with such strong model consensus on vigorous convective redevelopment. Increased pop grids some more and included heavy rain wording across mainly the eastern 1/2 of the CWA, where the flooding risk appears highest. Obviously, areas that have already received heavy rain today are most at risk for excessive runoff. We will hold off on a flash flood watch for now, but will be watching closely. && .SHORT TERM...(This evening through Tuesday) Issued at 251 PM CDT Mon Aug 13 2018 Thunderstorms developed early this afternoon across parts of southwestern Kansas near the aforementioned upper low given the lack of capping and weak diurnal surface heating. Scattered to numerous thunderstorms are expected through tonight, especially from Dodge City north and east near the upper level low. Clouds and areas of precipitation will keep temperatures on the moderate side, with lows tonight in the mid to upper 60s and highs Tuesday mainly in the lower to middle 80s. .LONG TERM...(Tuesday night through Monday) Issued at 251 PM CDT Mon Aug 13 2018 In the wake of the upper level low, warmer weather can be expected Wednesday and Thursday with highs warming into the upper 80s to lower 90s. The best chance of storms with the system on Thursday will be in central Kansas closer to the upper level feature. There are good chances of thunderstorms Saturday into early Sunday as the next upper level system approaches from the northwest. Temperatures will be held down by clouds and precipitation Saturday and Sunday. Drier and even cooler air should move into western Kansas by early next week, with lows possibly in the lower to middle 50s by Tuesday morning. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 500 PM CDT Mon Aug 13 2018 Complicated TAF issuance with scattered showers and thunderstorms expected to impact aviation through Tuesday morning, along with some lower ceilings to consider. Weak closed low will move little over western Kansas through 12z Tue. Models show showers and thunderstorms becoming numerous starting around 06z Tue, impacting DDC/HYS through 12z Tue. GCK/LBL will be more on the fringe of the activity, but close enough for a convective VCTS/CB mention in those TAFs as well. TEMPO groups were included at HYS/DDC when rain and convective impacts are most likely. Consensus of short term models bring IFR stratus into HYS 08-12z Tue, as was followed. Light and variable winds outside of convection. After 18z Tue, winds will increase and become north at 10-20 kts behind the departing closed low. && .PRELIMINARY POINT TEMPS/POPS... DDC 65 81 62 86 / 90 60 10 0 GCK 65 82 60 87 / 70 30 0 0 EHA 61 87 61 90 / 40 10 0 10 LBL 64 86 61 89 / 50 30 0 0 HYS 66 77 62 84 / 90 80 10 0 P28 68 84 65 87 / 80 70 40 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Turner SYNOPSIS...Finch SHORT TERM...Finch LONG TERM...Finch AVIATION...Turner
Area Forecast Discussion
National Weather Service Houston/Galveston TX
842 PM CDT Mon Aug 13 2018 .DISCUSSION... 00z 300 mb analysis shows a strong area of high pressure over the western Gulf with a weak upper trough over extreme West Texas. 850 mb analysis shows a weak high over LA and warming 850 mb temperatures at CRP (up to 22 C). There were a few shra/tsra late this afternoon and the latest HRRR shows some potential for a few isolated storms on Tuesday. Temperatures will likely to cool to near the dew point by 06-07z so some patchy fog is possible but the ground is drier than yesterday so confidence in fog formation is low. Decided to add patchy fog to the weather grids between 09-13z otherwise the rest of the forecast looks on track. 43 && .PREV DISCUSSION... /ISSUED 642 PM CDT Mon Aug 13 2018/ AVIATION... VFR and dry conditions are expected through most of the taf period with some MVFR ceilings and fog possible over the northern taf sites during the early morning hours. Any fog or low ceilings that develop should improve to VFR a few hours after sunrise. 11 PREV DISCUSSION... /ISSUED 318 PM CDT Mon Aug 13 2018/ SHORT TERM [Today Through Wednesday Night]... Radar shows a couple of isolated showers over Waller County. These showers look to be forming on a moisture gradient with moist air to the east and drier air to the west. SPC Mesoanalysis of theta-e shows this gradient well with an area of moisture convergence. Overall the atmosphere remains more subsident than ascending so the general trend will be for these showers to dissipate over the next hour or two. GOES 16 precipitable water imagery shows values around 1.2 to 1.7 with a north/south gradient of higher values to lower values. This drier air should also limit shower/thunderstorm activity the rest of the event especially along the coast. Analyzing the upper levels, 500mb analysis shows some weak ridging aloft over the NW Gulf with the upper low over SW Kansas. The expectation is for the ridge to expand over much of Texas through mid-week with the upper low lifting into the Plains and weakening. This should allow for subsidence to expand over the area and keep thunderstorm activity from forming. Forecast will basically go with 10 to 20 PoPs with maybe a shower or two if there is enough moisture. Higher moisture does not look to return to the area until Wednesday through the end of the week. LONG TERM [Thursday Through Monday]... Thursday into the weekend there looks to be a rise in moisture with precipitable water values getting up to 1.6 to 1.9 inches. This should provide enough buoyancy for convection each day although none of it will be particularly organized. Ridging aloft may break down enough to better support thunderstorm activity over the weekend. There is really no one signal indicating higher thunderstorm chances for one particular day. Forecast will go with mainly 20 to 40 PoPs which will be close to climo. Also the forecast will go with higher rain chances for the eastern portions of the area with lower PoPs or a dry forecast back to the west and southwest. Rainfall amounts will range from 0 to maybe a quarter inch depending upon how much shower activity develops. What rainfall did occur last week should have plenty of time to dry out and those that did not get much rain will likely see abnormally dry and moderate drought areas expand. Overpeck MARINE... Winds to remain generally light/occasionally moderate these next few days as an upper level ridge of high pressure remains over the area. Short-range models indicating isolated showers will be possible over the western half of the marine zones around sunrise tomorrow, but we should remain dry/quiet the rest of the day. Winds could briefly see SCEC criteria overnight as well. This overall pattern will remain in place the rest of the week. 41 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 96 74 96 75 96 / 10 0 10 0 10 Houston (IAH) 95 77 94 77 94 / 10 0 10 0 20 Galveston (GLS) 91 82 91 82 91 / 10 0 10 10 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ Discussion...43
Area Forecast Discussion
National Weather Service Jacksonville FL
935 PM EDT Mon Aug 13 2018 .UPDATE... A weak sfc trough oriented southwest to northeast across the forecast area provided a focus for showers and storms late aftn and evening. A sharp gradient in moisture noted in RAP and GOES analyses with PWATs of about 2.15 inches over northeast FL and tapering off to about 1.5-1.6 inches near Hazlehurst. With loss of heating...most of the showers and storms have dissipated with lingering showers and a few t-storms expected rest of tonight. Have lowered POPS to less than 40 percent rest of tonight with best chance for new development in the couple of hours over the southeast zones. After midnight, models suggest inland northeast FL will see an uptick in a low chance of new convection given mid level troughing and abundant moisture in the area, so planning to leave some POPs in for areas west of Highway 301 for later tonight. Lows in the lower to mid 70s. && .AVIATION...Prevailing VFR expected through the night but can`t rule out brief period of MVFR cigs or vsby from about 06z-15z due to abundant moisture and wet grounds from recent rains, especially around GNV. Another round of showers and storms expected on Tuesday...mainly during the aftn and early evening so VCTS is in place at this time. && .MARINE...No significant changes to the forecast with prevailing southwest winds overnight near 10-15 kt and seas around the 2-4 ft range, dominated by wind waves with periods of 4-5 seconds. Rip Currents: Low risk anticipated through Tuesday due to low surf heights and minimal ocean swell conditions. && .PRELIMINARY POINT TEMPS/POPS... AMG 73 92 72 92 / 30 40 10 40 SSI 76 88 78 89 / 30 40 40 40 JAX 74 91 73 91 / 30 70 30 40 SGJ 75 89 76 89 / 40 60 30 40 GNV 73 89 72 91 / 20 60 10 40 OCF 72 89 72 91 / 30 50 20 40 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ Shashy/Enyedi/Bricker
National Weather Service Jackson KY
1057 PM EDT Mon Aug 13 2018 .UPDATE... Issued at 1057 PM EDT MON AUG 13 2018 Forecast is still on track, and only minor adjustments were made to blend late evening obs into the forecast. UPDATE Issued at 901 PM EDT MON AUG 13 2018 Only very isolated showers remain, with no where near enough coverage to justify even a 20% POP. Away from dying showers, skies were mostly clear. In light of this, have done an overall reduction in forecast sky cover for tonight. && .SHORT TERM...(This evening through Tuesday night) Issued at 414 PM EDT MON AUG 13 2018 Current surface observations show a slow moving boundary to the southeast of Kentucky approaching the east coast. Radar has picked up on some isolated showers this afternoon, but shower activity will dwindle this evening. Isolated storms are also possible in the far east until early this evening as well. Upper level ridging and surface high pressure will then begin to take hold into Tuesday, bringing drier conditions to eastern Kentucky. The primary concern will be locally dense fog in the river valleys towards dawn Tuesday morning. There is also the potential for dense valley fog tomorrow night as well. The HRRR has had a decent handle on the timing and relative location of the isolated showers this afternoon. Therefore, have used the HRRR as a baseline for PoPs this afternoon into early this evening. Did include a bit more of the northern counties as well due to recent radar trends of some isolated showers to our north. With upper level ridging and surface high pressure setting up for Tuesday, stuck with guidance for temperatures through the short term. High temperatures will generally be in the mid 80s with low temps in the mid 60s. .LONG TERM...(Wednesday through Monday) Issued at 414 PM EDT MON AUG 13 2018 There is good model agreement to start the long term portion of the forecast, but agreement and confidence in the details of the forecast decrease as we move into the weekend. For Wednesday morning both the GFS and ECMWF show surface high pressure will be centered over the central to southern Appalachians with mid/upper level ridging through the OH valley. A mid/upper level short wave trough and associated surface low will be over the eastern plains. The pattern will be fairly progressive with the upper level short wave trough shifting east and a surface warm front advancing towards the area on Wednesday. The short wave trough looks to dampen out as it moves northeast towards the Great Lakes on Thursday as a second short wave trough advances east from the northern Plains. At the surface a cold front will move towards the area on Thursday, but as the initial upper level wave damps out the front will slow and will still be northwest of the area on Friday. The advance of the second short wave trough may result in the cold front pushing on through the area over the weekend, but this is uncertain. It does appear that even if the front pushes south of the forecast area this weekend it will stall and will likely shift back north by early next week. For sensible weather the rather active pattern will result in daily chances of showers and thunderstorms, but confidence in the precipitation forecast is fairly low. There is higher confidence in the general temperature forecast with temperatures remaining fairly close to seasonal normals through the period. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 901 PM EDT MON AUG 13 2018 A few showers lingered over extreme eastern KY at the start of the period, but continued on a decline and should be gone shortly. Fog will develop in valleys again tonight, and grow in depth and breadth through sunrise. It is expected to again affect TAF sites with IFR or worse conditions overnight into early Tuesday morning. Outside of the fog, VFR conditions will prevail. Winds will be light. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...CGAL LONG TERM...SBH AVIATION...HAL
Area Forecast Discussion
National Weather Service San Francisco Bay Area
439 PM PDT Mon Aug 13 2018 .SYNOPSIS...Temperatures will be near to slightly below seasonal averages through midweek as a modest marine layer and onshore flow persist over the region. High pressure is then forecast to rebuild toward the West Coast late in the week and into next week bringing warmer temperatures to the interior. && of 01:22 PM PDT Monday...The deepening marine layer, increased onshore flow and cooler air mass aloft have resulted in more coastal cloud cover and cooler conditions region- wide. Temperatures are running a few to as much as 10 degrees F cooler compared to this time yesterday with the greatest difference being in places such as Livermore and Hayward. In addition, stratus that developed overnight has retreated to the coast with many locations such as San Francisco and Monterey still under cloud cover. These conditions are forecast to change very little through midweek with temperatures at or slightly below seasonal averages. May even see patchy coastal drizzle develop overnight with low clouds spreading back inland into the valleys. Periods of increased mid/upper level moisture are also forecast to advect northward across the region and result development of high clouds. At this time, sufficient moisture and instability for high- based convection appears to stay inland and to our north. However, will closely monitor the potential for any convection in the coming days. Upper level high pressure is then forecast to strengthen over the Desert Southwest and build toward the California coast late in the week. As a result, the marine layer will likely become more compressed and onshore flow will weaken. 850 MB temperatures will also be on the increase and result in a warming trend for interior locations. The end result, more widespread 80s and 90s are likely for the interior with our warmest locations across the region reaching the 100 degree F mark. Meanwhile, coastal areas are likely to remain seasonably cool with periods of overnight/morning low clouds and patchy fog. Overall, dry weather conditions are likely to persist through the forecast period. && of 4:39 PM PDT Monday...For 00z tafs. Stratus is currently situated along the coast and beginning to move inland as the marine layer sits at around 1500 ft. MVFR/IFR conditions are expected overnight and into the morning hours at most locations. Clearing is forecast tomorrow morning around 17z-18z. Latest run of the HRRR smoke forecast shows increased near surface and vertically integrated smoke overnight and through much of the day tomorrow. This will likely create slant range visibility issues. Breezy winds will continue into the evening before diminishing in the overnight hours. Expect onshore winds to increase again by tomorrow afternoon, especially for KSFO. Vicinity of KSFO...VFR/MVFR with BKN cigs currently over the airport. IFR cigs are expected to prevail starting late tonight and lasting through around 17z. As mentioned above, the latest run of the HRRR smoke forecast suggests an increase in near surface and vertically integrated smoke over the Bay Area late tonight and through much of tomorrow. This will likely create slant range visibility issues once the stratus clears. Winds will subside overnight before gusty onshore winds return tomorrow afternoon. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...Stratus has already begun to intrude into the Monterey Peninsula and is starting to move into the Salinas Valley. Cigs are a bit higher to start off the late afternoon at around 1300 ft, but are expected to lower to IFR/LIFR overnight. Generally light winds through the period. && of 02:30 PM PDT Monday...Lighter northwest winds offshore today as the pressure gradient weakens. Locally breezy to gusty winds will continue to prevail along the coast especially along the Sonoma coastline and south of Point Sur. Weak mixed swell overall with a longer southerly swell component. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm until 9 PM SCA...Pigeon Pt to Pt Pinos 0-10 nm until 9 PM SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 2 AM && $$ PUBLIC FORECAST: RGass AVIATION: AS MARINE: DRP Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Mount Holly NJ
1019 PM EDT Mon Aug 13 2018 .SYNOPSIS... A weak front will move little through Tuesday as weak surface lows move through the northern Mid-Atlantic along it. The front will move offshore Wednesday. Low pressure will move from the Great Lakes on Thursday to New England and adjacent southeast Canada on Saturday. An attendant cold front will progress through the region Friday night and Saturday but is expected to stall near or just south of the area through early next week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 1015 pm mesoscale update: Flash flood watch has been dropped as convection is clearly on the downward trend in the past hour. Will reevaluate potential for additional flooding tomorrow before determining if another watch is needed. 930 pm mesoscale update: Storms to the west/northwest of Philly have exhibited occasional/brief downburst signatures as seen on TPHL. Have issued several severe thunderstorm warnings for these storms based on these signatures and the very saturated soils (making trees especially susceptible to falling in strong winds). Recently, outflow has spread eastward from the cells, so expect general weakening in the next hour or two. Though these storms are progressing reasonably quickly, have seen a few reports of renewed flooding in the usual poor-drainage spots in Chester and Montgomery Counties. Overall forecast is in good shape for now. No changes to the flash flood watch yet given ongoing convection, but the threat is diminishing with time tonight. 730 pm mesoscale update: Showers are initiating in Berks and Montgomery Counties as storms and resultant outflow from central Maryland propagate into south-central PA and the Eastern Shore of Maryland. The showers in southeast Pennsylvania may not move much, so locally heavy rainfall may occur. However, the cores are rather weak and do not have a history of lasting more than about thirty minutes before dissipating. Nevertheless, these are developing in very sensitive areas (i.e., saturated and/or flooded), so will be monitoring closely for additional flood potential this evening. Meanwhile the storms near/just west of Chesapeake Bay weakened considerably once reaching the bay, but outflow will spread east through Delmarva this evening. Winds to 49 mph occurred at Tolchester Beach as the outflow passed, and gusts to 40 mph or so may occur through northern/central Delmarva during the next hour. 515 pm update: Updated PoPs across the area for the evening hours. Convection in central Maryland is expected to progress to the Eastern Shore during the next few hours. Convection- allowing models indicate (to varying degrees) these storms will gradually diminish after sunset, but this process could be slow given the high moisture content of the air and associated slowing effects on diminishing instability. Additionally, convection currently in central PA suggests that the environment may be recovering sufficiently for subsequent development farther south and east into south-central/southeast Pennsylvania before sunset. Starting to see some radar echoes in Berks County, indicating this threat may be increasing. The HRRR gives some indication of this, though it is notably not handling convection in general well this afternoon. Also made some adjustments to temperature/dew point grids through the evening hours, as current readings were higher than forecast in southern New Jersey and portions of Delmarva. Previous discussion... Several flood warnings remain in effect across the area as a result of the heavy rain that fell this morning (5-8 inches in some spots). Please follow detours and do not drive around barricades. Turn Around, Don`t Drown! An upper level closed low slowly moves across the region tonight. Meanwhile, at the surface, low pressure will continue to move along a stalled boundary and up our coast this evening. Scattered convection is occuring in the forecast area, especially across parts of the region that have been able to see some sunshine today. While the storms are moving, there is not a lot of low across the region and this means the storms will move slowly, if at all. The slow nature of the storms combined with the high PWATs across the region means that the storms will be efficient rainmakers and heavy rain will fall. As the sun sets, we should see storms diminish in coverage as the instability is largely driven by surface heating this afternoon and evening. Energy will continue to rotate around the upper low and we could see some showers continue through the overnight period as a result. With the wet antecedent conditions and keeping in mind that a good deal of rain fell across portions of the area this morning, we have kept the Flash Flood Watch in place through tonight. Model shows that we could see some clearing tonight across the region. With light winds and a lot of low level moisture in place, some fog may develop. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... The upper low will start to move slowly to the northeast on Tuesday. At the surface, the stalled frontal boundary will move little but should make a slight shift towards the coast. Another wave of low pressure is forecast to move along this boundary, bringing in another round of convection and showers through the day. Highs will generally be in the 80s across the region, with some 70s across the southern Poconos and parts of northwest New Jersey. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... With a plethora of short-term concerns, spent little time on the long-term forecast today. In general, the details have not changed much for the rest of the week into the following weekend. The midlevel trough plaguing the Northeast early this week will be ejecting into the Canadian Maritimes and offshore the New England coast on Tuesday night and Wednesday. Lingering chances of precipitation Tuesday night (especially offshore and in the northern CWA) will decrease with time. Kept PoPs out of the forecast Wednesday, but I am a little concerned about an upstream (weak) vort max moving southeastward into southern New England. The 12Z NAM hints at some convection breaking out during the day, though it looks like the most favored locations for such convection are north of the area. Nevertheless, would not be surprised if we need to add some PoPs to areas near/north of I-80 in later forecasts. Otherwise, the rest of the region will see rising heights and partially or mostly sunny skies. This spells a hot day for the area. Shortwave ridging enters the area Wednesday night and Thursday. Associated large-scale subsidence should allow for a dry period and warm temperatures. Kept temperatures close to a statistical blend, but I suspect highs will need to be nudged upward in subsequent forecasts given observed model biases in the past. MEX guidance is particularly warm on Thursday, with heat indices in the upper 90s in much of the urban corridor and Delmarva. Next system approaches the area on Friday and Friday night, with a surface low progressing from the Great Lakes to the Northeast during the period. A cold front will progress into the Appalachians during the day and enter the CWA by Friday night. Timing differences exist among the operational simulations, but the overall evolution is reasonably similar at this time range. Given timing of the front, convection looks to peak in intensity west of the area during the afternoon (possibly affecting the western CWA) and nocturnally weaken as it moves into the heart of the region. Severe threat looks fairly low anyway given the weak shear and CAPE profiles. Of more concern is what happens to the front this weekend, as there are indications it may slow to a crawl near or south of the CWA. To varying degrees, operational models show subsequent rounds of convection developing along the increasingly quasi- stationary boundary. We`ve seen this scenario before (many times) this summer, with indications another heavy rain event may occur somewhere in the Mid-Atlantic during this time frame. There is some consensus that the southern CWA may be most at risk for this (in our area), but model discrepancies are large by this point. The pattern, though, suggests that this is yet another period to watch closely in the upcoming days. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Tonight...Generally VFR, but there is some potential for either sub-VFR VSBYs (patchy fog) or sub-VFR CIGs (low stratus) after midnight, particularly north/west of KPHL. Additionally, monitoring storms closely northwest of KPHL, with outflow nearing the Philly terminals at this time, and lightning cannot be ruled out (especially at KPNE and KTTN). Winds light and variable, but stronger near precip/outflow. Very low confidence. Tuesday: Generally VFR, but scattered storms are expected to develop during the afternoon. Local sub-VFR conditions possible in proximity to showers/storms. West winds 5 to 15 kts. Moderate confidence. OUTLOOK... Tuesday night: May see some remnant showers/storms north and east of the Philly terminals, but chances should diminish with time. There is also some potential for patchy fog. West winds generally below 10 kts. Low confidence. Wednesday: VFR. Winds west 5 to 15 kts. Moderate confidence. Wednesday night and Thursday: Predominantly VFR, but there may be some patchy fog between midnight and 8 am or so, especially at the more susceptible sites. Light/variable winds Wednesday night becoming southwest 5 to 10 kts on Thursday. Moderate confidence. Thursday night and Friday: Predominantly VFR, but increasing chances of showers/storms through the period, with local sub- VFR conditions possible. South to southwest winds 5 to 15 kts. Moderate confidence. Friday night and Saturday: A chance of showers/storms, especially Friday night. Local sub-VFR conditions probable, and longer-duration sub-VFR conditions possible in proximity to a frontal passage. Southwest winds 5 to 15 kts in advance of the front Friday evening/night becoming west or northwest behind the front Saturday. Low confidence. && .MARINE... Sub-Small Craft Advisory conditions are expected to continue across the area waters. A boundary across the waters has the winds in different directions this afternoon, with northeast winds across the northern waters and southwest winds across the southern waters. Winds should become more southwest overnight and then pick up around 10 to 15 knots for Tuesday. Seas are 2 to 4 feet on the ocean and around 1 to 2 feet on the Delaware Bay. OUTLOOK... Tuesday night through Saturday: Sub-advisory winds/seas expected, though seas may approach advisory levels on Friday and Saturday as a cold front approaches the region. A chance of showers/storms Tuesday night and again Friday and Saturday. RIP CURRENTS... There is a low risk for the development of dangerous rip currents today and Tuesday. && .TIDES/COASTAL FLOODING... We are expecting spotty minor coastal flooding with this evening`s high tide. It will be due mainly to the high astronomical tides associated with the new moon. However, the flooding due to the tides is not anticipated to be widespread enough to warrant another Coastal Flood Advisory at this time. We will continue to monitor gauges closely, especially given the heavy rainfall that has occurred today in Monmouth/Ocean Counties. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ Synopsis...CMS Near Term...CMS/Meola Short Term...Meola Long Term...CMS Aviation...CMS Marine...CMS/Meola Tides/Coastal Flooding...
Area Forecast Discussion
National Weather Service Pueblo CO
308 PM MDT Mon Aug 13 2018 .SHORT TERM...(This evening through Tuesday) Issued at 257 PM MDT Mon Aug 13 2018 Currently...Well defined upper low per high level water vap sat pix imagery was spinning, with the center being over the TX/OK phdl/NM region. Showers and thunderstorms were noted along the contdvd, and were moving at a pretty good clip southward. More isold activity was noted along the mtns/plains interface. Over the plains skies were mostly clear, but a few more clouds were noted over the far eastern plains. Temps at 2 pm were generally in the 80s over the plains with 70s in the valleys. Temps were in the 50s and 60s in the mtns. Skies were hazy all areas due to the Calif smoke. Rest of today into tonight... Overall best chance of showers rest of this afternoon into the early evening along the Contdvd. Guidance was showing some isold activity developing over the far eastern plains late this afternoon into the evening hours. Guidance also show some showers redeveloping over the far eastern plains later tonight. The I-25 corridor east of the mtns should remain completely dry. Min temps tonight should be in the 50s to around 60, with 30s and 40s in the mtns/valleys. Cant rule out some 30s in the smaller valleys. With storms moving pretty quickly southward, believe any flash flood threat on any burn scars is low. Tomorrow... Upper low is fcst to lift off to the northeast with time. Some clouds and isold showers will be possible over the far eastern plains tomorrow. Showers and thunderstorms should be a bit more numerous over the higher terrain during the afternoon time period. Flow over the upper 2/3rds of the atmosphere will transition to northwesterly so we should see some storms move off the higher terrain onto the plains later in the afternoon, especially over the divides. Max temps tomorrow should be 1 to 2 degrees cooler than today. Cant rule out some isold heavier rain in the higher terrain tomorrow. .LONG TERM...(Tuesday night through Monday) Issued at 257 PM MDT Mon Aug 13 2018 Thunderstorm activity will pull southeastward Tuesday night, focusing along the front as it drops southward. Most activity diminishes across southern CO by midnight according to the NAM and GFS. Wednesday looks to be the more active day for southern CO as an upper level trof glances through NE CO. Northwest flow aloft increases as a result, which helps to increase deep layer shear. Upslope flow gives way to development of lee trof/sfc low which is progged to kick eastward across the plains. This may serve to dry out surface dew points along portions of the I-25 corridor and decrease CAPE a bit. However, still looks like around 1500+ J/kg of CAPE will be be present, particularly along the Palmer and Raton ridges as well as the southeast plains east of KLHX. This appears to be where NamNest is painting the stronger convection. Either way, it appears sufficient parameters will be in place to support a severe thunderstorm threat Wednesday afternoon and evening. Some differences exit for Thursday as NAM holds on to some low level moisture and instability for afternoon while GFS starts to dry things out. With the upper ridge rebuilding deep layer shears may decrease some which should decrease the severe thunderstorm threat. Will carry isolated to scattered thunderstorms this day with greatest coverage over the mountains. Friday and Saturday look similarly active as yet another upper trof moves by to the north, though there are some timing differences between the ECMWF and GFS. Eventually this sends another front through the southeast plains with the potential for another uptick in moisture and thunderstorm chances early next week. Overall looks like a relatively active period for thunderstorms the next several days. -KT && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 257 PM MDT Mon Aug 13 2018 VFR conditions are anticipated during the next 24 hours at all 3 taf sites; KPUB, KALS and KCOS. HRRR is trending drier in the low levels later tonight so will likely not mention any lower cigs at KCOS prior to sunrise. Winds next 24 hours should be light and mainly diurnally driven. It is possible a -tsra may be in the vicinity of KCOS at the end of this fcst period. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HODANISH LONG TERM...KT AVIATION...HODANISH
Area Forecast Discussion
National Weather Service Tucson AZ
227 PM MST Mon Aug 13 2018 .SYNOPSIS...Isolated afternoon and evening thunderstorms can be anticipated through Tuesday. Thereafter, an increase in moisture will result in an upswing in thunderstorm activity Wednesday through Thursday. Along with this upswing in thunderstorms, cooler temperatures can be expected. More typical monsoon activity and temperatures will return for the coming weekend. && .DISCUSSION...Isolated showers and thunderstorms were developing this afternoon across parts of southeast Arizona. Recent HRRR solutions continued to advertise limited thunderstorm activity through tonight. GFS model showed the upper high becoming centered over east-central Arizona on Tuesday with the flow more southeasterly. This shift in the flow pattern should start to advect deeper moisture back into the area by Wednesday. Based on this moisture advection and an inverted upper level trough moving out of northern Mexico on Wednesday, still expect an upswing in shower and thunderstorm activity Wednesday through Thursday. Lingering moisture into the weekend should be sufficient to support daily thunderstorms. Along with the anticipated increase in rain chances, models showed cooler daytime temperatures Wednesday and Thursday. && .AVIATION...Valid through 15/00Z. Isolated SHRA/TSRA will continue into this evening and mostly diminish after 14/04Z. Brief MVFR conditions possible with TSRA, otherwise SCT-BKN cloud bases generally 8k-12k ft AGL. Outside of thunderstorm gusts, expect mainly light NWLY SFC winds. The exception will be near KSAD where winds will be 14-18 kts with higher gusts possible. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...The pattern remains favorable for isolated thunderstorm development areawide through Tuesday. Thereafter, increased moisture will result in scattered showers and thunderstorms as early as Wednesday afternoon and continuing into the weekend with localized areas of heavy rain possible. Near or slightly below normal temperatures will continue throughout the forecast period. 20-ft winds will be terrain driven at less than 15 mph, except for in and around thunderstorms where strong outflows may occur. The Gila River Valley including Safford will see slightly elevated winds this afternoon and again Tuesday to around 15-20 mph. in Tuesday to around 15-20 mph. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at