Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/08/17


Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
601 PM MDT Fri Jul 7 2017 .AVIATION... 00Z TAF CYCLE Isolated convection will continue through 08/05Z. Favored area for storms will be across nern NM where a more organized band will drop south out of sern CO. Stronger storms will result in heavy rain/small hail and MVFR cigs/vsbys. Storm coverage will increase somewhat Saturday afternoon as moisture continues to seep in from the south overnight. 33 && .PREV DISCUSSION...315 PM MDT Fri Jul 7 2017... .SYNOPSIS... Dry thunderstorms will be more popular west of the central valley with better chances for wetting precipitation over the north central mountains today. The upper high over the Four Corners will weaken and begin to move east into the front range of the Rockies this weekend. This will allow increased coverage of wetting precipitation over New Mexico heading into next week. Temperatures will remain fairly consistent with daytime highs near average, and overnight lows a bit over average. && .DISCUSSION... Convective activity fired up a little earlier this morning over the Sangre`s before noon, and convection is now active over the north- central and western high terrain. Dropped PoPs a bit over the Gila today to reflect drier mid-level air aloft there, reflected in the GOES-16 low and mid-level WV imagery. The crop of cu there is also quite pitiful for this time of afternoon. The NAM12 and HRRR latched onto lingering convection into the NE plains overnight, and thus increased PoPs there accordingly given lastnight`s activity. Overall, no major changes to the forecast with this run. Models continue to show the Four Corners high flattening as a trough moves into the Pacific NW this weekend. Models are hinting at the chance for isolated svr storms over the NE Saturday with SE sfc flow meeting NW flow aloft. Gusty outflow winds and hail would be the main threat. The high continues to weaken and flatten into next week as it also moves east, allowing increased monsoonal like flow to penetrate into New Mexico. Subsequently, the coverage of precipitation looks to increase, favoring mainly the higher terrain over western NM, for early to middle of next week. More wetting precipitation can be expected with next week`s storm activity compared with what we have been seeing recently. The high begins to build again and move towards the Great Basin by the end of next week, reducing precipitation coverage a bit. 24 && .FIRE WEATHER... Models have provided little change in the overall weather theme the next several days. Upper high will meander around the greater Four Corners area. Drifting somewhat to the northwest of the four corners this weekend but then drifting back to the east during the earlier half of next week due to a Pacific trough across the NW third of the nation. Either way, moisture currently trapped within the high will only increase and especially favor western and central areas in terms of storm coverage. Wetting rain footprints associated with the cells will also increase as the days progress. Gusty outflows and strong downdrafts will be a concern during the next few days. Some of the outflows will be able to travel over 50 miles. Models are showing a persistent breezy SSW wind pattern across the eastern plains as next week progresses. This is a known breezy pattern and sometimes the models under forecast the speeds. Decided to hedge speeds above blended model guidance by 2 to 3 mph across the eastern third to account for this possibility. 50 && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$ 24
Area Forecast Discussion
National Weather Service Wakefield VA
1039 PM EDT Fri Jul 7 2017 .SYNOPSIS... A weak cold front will push off the coast this evening. Another cold front will approach the Mid Atlantic from the northwest late tonight into Saturday and slide through the region Saturday evening. This front settles across the Carolinas Sunday as high pressure builds in from the northwest. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Initial complex of storms that moved across the Ohio Valley weakened north of the area with one shower making it into Dorchester county with a nice outflow boundary showing on the DOX radar. Outside of that shower, the region is very quiet weatherwise with clear sky and light wind. That should continue through most of the night, but will need to monitor the complex of storms back in WV/KY that could impact the region toward morning. However, like the first wave, this complex is already showing signs of weakening and with the drier air that is in place east of the mountains, seeing dew points in the low 60s along the I-81 corridor, think this complex will receive the same treatment as the first keeping most areas dry over night. Temperatures in the lower to mid 70s should prevail overnight, except for in the Piedmont where readings could drop into the upper 60s. Prev discussion... Current wv imagery depicts an upper trough digging across the Great Lakes with a ridge anchored over the subtropical wrn Atlantic resulting in SW flow aloft across the Mid-Atlantic. At the surface, a weakening cold front (mainly comprised of a brief wind shift and a dewpoint gradient) is pushing across the area and triggering iso showers/tstms across the Peninsula and Tidewater as of 330pm. A few additional showers/tstms may develop across NE NC but otherwise mainly dry conditions are expected across the area through 6 pm. Temperatures this aftn are generally in the mid/upper 80s, with a few low 90s in far SE VA/NE NC and across the far NW piedmont within the slightly drier airmass behind the front with better mixing. An MCS is currently racing sewd across the Ohio Valley. The main impact from this system is expected to remain W of the mountains in the presence of higher instability. However, the past few runs of the HRRR suggest some convection could develop along outflow to the lee of the mountains across nrn VA through the Delmarva, so the nrn tier counties will have a 20-30% chc for tstms this evening. 08/18z RAP suggests 0-6km shear increases to ~35kt with steepening 850- 700mb lapse rates, so any tstms could contain strong wind gusts. The initial front will push offshore and wash-out overnight, with the low-level flow becoming SW once again, and sky cover becoming partly cloudy to mostly clear. Continued warm and humid tonight with lows ranging from the upper 60s/around 70 W to the low/mid 70s at the coast. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... A cold front over the Midwest this aftn will approach from the NW Saturday. Downslope flow should prevail once again with high temperatures rising into the low/mid 90s. Dewpoints should be lower inland, low/mid 60s, but remain in the low 70s for inland SE VA/NE NC where heat indices will reach around 100, and perhaps the low 100s near the Albemarle Sound with locally higher dewpoints. Downslpe flow will initially suppress convection through much of the day Saturday. However, the RRQ of a 100kt jet over New England will arrive later in the aftn along with a mid-level shortwave trough and this should help trigger convection. PoPs range from 20-30% from the Piedmont to the MD Ern Shore, mainly after 18z, with 30-50% across SE VA/NE NC during the late aftn/evening in vicinity of higher surface dewpoints and higher low-level theta-e. 0-6km bulk shear reaches 30-40kt with the best instability, which could result in some organized line segment or multicells capable of producing strong wind gusts. The upper trough spreads across the Ern Conus by Saturday night/Sunday. There will be an airmass change behind the front with drier air filtering in from the NW late Saturday night. Lows Saturday night range from the low 60s NW to the low 70s SE, followed by highs Sunday of 80-85F E, and mid/upper 80s well inland, with aftn dewpoints ranging from the upper 50s NW to the upper 60s SE. A 30-50% chc of showers/tstms will linger through the early overnight hours across NE NC/far SE VA as the front slowly pushes through, with a ~20% chc of sea-breeze convection Sunday aftn for NE NC, but otherwise dry across the region Saturday night/Sunday. The subtropical ridge will gradually rebound Sunday night into Monday as the trough lifts to the NE. The low-level flow will gradually become southerly by Monday. Lows Sunday night range from the mid 60s to around 70, followed by highs Monday in the upper 80s to around 90, with dewpoints in the 60s. The current forecast has PoPs below 15%, but very iso sea/bay breeze convection is possible Monday aftn. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... Washed out frontal boundary lifts north through the region Monday night into Tuesday. Meanwhile, persistent upper level troughing over the nern half of the country and high pressure off the Southeast Coast will allow pulses of shortwave energy/moisture to cross the area at times throughout the long term forecast. Most recent trend is to dry things out more even though afternoon/evening thunderstorms may be possible. Temperatures will be above normal throughout the long term period. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... VFR conditions across the CWA with only a few clouds. Some showers and thunderstorms moving across Northern Va/DC area and may affect the Maryland Eastern Shore by 01-02Z. Do not expect this to be widespread and should be out of the region in a short period of time. Another complex of thunderstorms approaching WV at this time but models show it falling apart before reaching our area. Winds will be mostly SW tonight less than 10 kts. There could be some early morning fog/haze but should not be significant. A cold front pushes across the region Saturday, followed by high pressure Sunday and Monday. Conditions should remain VFR through the weekend. && .MARINE... Update...SCA flags cancelled for Currituck Sound. Wind gusts have diminished below 20 knots. Previous discussion... Unsettled weather through Saturday will become more focused over the srn waters Sunday/Monday...with periods of afternoon/evening thunderstorms at times Tuesday into mid week. Winds generally west 10-15kt late this afternoon and are expected to diminish into this evening. Will need to keep a close eye on a severe weather complex racing across Ohio. If it holds together past the Appalachians, then thunderstorms with strong wind gusts may be possible late this evening into the early morning hours over the waters. Mariners should remain aware of the potential for rapidly changing conditions during this timeframe. A cold front approaches from the northwest on Saturday and is expected to slowly cross the waters late Saturday afternoon into the evening. The front then stalls invof Carolina Coast Sunday into Monday (slowly washing out during this time) and focusing showers/storms over srn waters during this time. Winds generally SW-W aob 15kt ahead of the front...becoming NW-N 10-15kt behind the front. A period of cold air advection late Saturday night into Sunday morning may result in a period of near-SCA conditions for Ches Bay with waves up to 3ft during the strongest winds. Otherwise, winds aob 15kt become NE-E Sunday afternoon into Sunday night...then SE Monday...becoming S-SW Tuesday/Wednesday as a lee trough develops with high pressure off the Southeast Coast. Seas average 2-3ft (3-4ft possible nrn waters Tuesday night into Wednesday morning). Waves generally 1-2ft Ches Bay (2-3ft at times south of New Point Comfort to the mouth of the Bay). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...AJZ NEAR TERM...AJZ/ESS SHORT TERM...AJZ/SAM LONG TERM...BMD AVIATION...MRD/JEF MARINE...BMD
Area Forecast Discussion
National Weather Service Bismarck ND
929 PM CDT Fri Jul 7 2017 .UPDATE... Issued at 926 PM CDT Fri Jul 7 2017 High pressure extending from central Alberta/Saskatchewan southeast through North Dakota will maintain mainly clear skies and and dry weather over the region tonight and Saturday. The current forcast looks good with no changes. UPDATE Issued at 549 PM CDT Fri Jul 7 2017 Latest observations place surface low pressure across far southwest North Dakota with a warm frontal boundary extending from the low south through western South Dakota. Bowman radar shows scattered showers along the warm front. The latest HRRR ensemble forecast place isolated showers across northwest South Dakota with just a slight chance in North Dakota over the next 2 hours. Based on the latest radar do not think there will be any chance in North Dakota. So far current forecast looking good with no changes. && .SHORT TERM...(This evening through Saturday) Issued at 224 PM CDT Fri Jul 7 2017 The short term appears quiet and warm. High pressure will slide off to the east Saturday and warm air advection will kick in across western North Dakota. Temperatures in the 90s can be expected for most of western and central North Dakota. Very dry conditions across western North Dakota may lead to near critical fire conditions across the west tomorrow, however, it appears winds will remain rather light at this time. .LONG TERM...(Saturday night through Friday) Issued at 224 PM CDT Fri Jul 7 2017 Near critical fire conditions Sunday will highlight the long term. Above normal temperatures are expected for the next week and beyond as ridge maintains its position over the western United States. Given dry soils and a well mixed boundary layer we leaned on the warmer edge of the 12 UTC guidance. This means widespread temperatures in the low to mid 90s are expected most days, especially in western and south central ND. The hottest day of the current forecast period may be Sunday when a weak mid-level shortwave trough rounds the ridge and leads to additional compressional warming and mixing across the Northern Plains. Critical fire conditions are possible on Sunday as breezy conditions may develop across southwest ND behind a surface pressure trough and wind shift for at least a few hours Sunday afternoon. Precipitation chances will generally be limited during the period, but some chance of thunderstorms will exist Saturday night, mainly across northern North Dakota. Another, somewhat greater chance of storms may occur on Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 549 PM CDT Fri Jul 7 2017 At 6 pm CDT surface low pressure was tracking across the far southwest portion of North Dakota. High pressure will remain over teh Northern Plains. VFR conditions forecast through the 00Z TAF period. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...AJ LONG TERM...AJ AVIATION...WAA
Area Forecast Discussion
National Weather Service Caribou ME
1106 PM EDT Fri Jul 7 2017 .SYNOPSIS... A cold front will approach the area tonight from Quebec and cross the region on Saturday. Another cold front will approach on Sunday and stall over the region Sunday night into Monday. && .NEAR TERM /THROUGH SATURDAY/... 1105 PM Update... Adjusted the pops to align better w/the radar returns showing heavy rainfall axis shifted across the nw areas. HRRR doing well w/the handling of this rainfall. MRMS data showing up to 1.5 inches in the last 3 hrs across this area. Instability has weakened considerably this evening. Some isolated flashes still seen in the nw areas. So, kept isold tstms in through 2 AM. Sounding data showed the llvls stabilizing further overnight. Low pres seen on the latest sfc analysis moving across the Gulf of Maine bringing the western edge of the rain shield to the coast. Kept 30-40% pops for the coast overnight but things should drop off by early morning. The other factor is fog potential especially downeast w/some breaks in the clouds. Kept fog in the fcst for the overnight period. Previous Discussion... Activity will die out slowly after midnight, but patchy fog and widespread low stratus appears likely to overspread CWA overnight and persist into the morning. Some burn-off of the fog and low stratus is expected in the morning, with at least patchy sunshine providing for some warming, especially for northward of Bangor. Given the ample moisture, forcing from an approaching cold front, and increasing shear, at least a marginal risk for severe storms is expected. As a result, kept in the enhanced wording for the areas of likely or higher POPs. The front will likely come through sometime after 21z, with the severe risk dying down behind the front. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... On Saturday evening, the cold front will be exiting the forecast area and storms will be quickly winding down as the upper trough weakens. Low clouds will move out with dry west winds. There`s not a lot of cold air behind this front and highs on Sunday will be warmer than Saturday for many locations...especially on the coast due to offshore flow. However, it is a dry Canadian air mass and humidity will be lower for Sunday...and much lower towards northern Aroostook County. The mixing layer will be quite deep and produce some wind gusts up to around 25 mph...mostly in northern zones. A weakening shortwave will approach from the NW Sunday afternoon and evening. The associated cold front is not expected to generate much precipitation at this point. The only pops will be in the far northwestern zones for light showers by late afternoon. Lows on Sunday night will vary from the upper 40s in the Allagash on the north side of the cold front. Upper 50s are forecast for Bangor and the Down East region on the other side of the front. The frontal boundary will stall Sunday night into Tuesday while a succession of upper level shortwaves move from the NW. The exact position where the front stalls in the forecast area remains uncertain, but a shortwave arriving Monday afternoon will set off scattered thunderstorms. The left rear entrance region to a strong upper jet will be in the area to enhance any storms and shear looks robust. The exact position where the front stalls will determine where surface heating occurs and where the thermal boundaries set up. For now will place the highest pops for thunderstorms across central portions of the forecast area. The differential heating and thermal boundaries currently look like they`ll set up from south-central Piscataquis County towards southern Aroostook County. This means highs around 80F at Bangor, but only around 70F at Fort Kent. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... On Monday night, thunderstorms will taper off. The next shortwave moving southeastward from Quebec on Tuesday looks even more active with the potential for strong thunderstorms. There will be a lot of shear, strong cold air advection aloft and warm and humid air at the surface. Following this front, a dry and cool Canadian air mass should provide fair weather Wednesday and Thursday with very low humidity. A warm front will overrun this dry air later Thursday. The area will be back in the humid air Friday with the threat of another round of afternoon convection. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: Areas of MVFR to IFR conditions are expected in shower and thunderstorm activity for HUL thru FVE through 04z; otherwise VFR conditions are expected. However, fog and low stratus will form around or after midnight and persist through at least 12z. The fog is expected to burn off around that time, but some low stratus may linger at some terminals into the morning, keeping IFR conditions in place longer. SHORT TERM: A lot of low level moisture will cause some IFR cigs or vis Saturday night. Any low cigs will quickly be eradicated Sunday morning and VFR is expected for all sites by mid-morning Sunday and this condition will continue through Monday. The only possible exception will be some patchy fog towards the coast later Sunday night into Monday morning. Thunderstorms are a threat Monday afternoon into the evening. IFR cigs and vis are probable Tuesday night...followed by thunderstorms on Tuesday afternoon. && .MARINE... NEAR TERM: Some rain continues offshore through at least midnight, but as the rain clears out, areas of dense fog are expected to cut visibility tonight. The fog may ease a bit Sat morning, but may not fully clear until the afternoon. SHORT TERM: Fog will gradually move away Saturday night. Some patchy fog may return Sunday night briefly. Denser fog seems probable to arrive Tuesday into Tuesday night. Continued to apply reductions to model winds and seas with a persistent inversion over the cold waters. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && $$ Near Term...Hewitt
Area Forecast Discussion
National Weather Service Dodge City KS
639 PM CDT Fri Jul 7 2017 ...Updated Aviation Section... .SHORT TERM...(This evening through Saturday) Issued at 255 PM CDT Fri Jul 7 2017 A surface-850 mb frontal zone spreading southward later this afternoon will allow for boundary layer moisture pooling just ahead of it, mainly over south southern into west central counties. This will be the favored area for isolated to a few strong to severe storms in the 23-02Z timeframe. HRRR remains ambitious with convective development this afternoon, while the morning runs of WRF/NMM/ARW have backed off significantly from this surface based development, while maintaining the solutions of all models for more widespread convective development, aided by a shortwave exiting the central Rockies very late evening and overnight. Combination of post synoptic front and possible modified surface air from convection could keep temperatures Saturday as much as 10 degrees cooler than this afternoon, although reality may only bring about 5 degrees off. The thunderstorms risk appears similar late Saturday with possibility of isolated widely scattered hail/wind storm late day or evening with any minor vort max dropping though the northwest flow. .LONG TERM...(Saturday night through Friday) Issued at 255 PM CDT Fri Jul 7 2017 Pattern adjusts by Sunday with strong southwest 850 mb downslope surface flow over the entire area. This will bring an end to the 60s dew points in the forecast area, although dew points may still be in the 50s across south central Kansas counties. The drier air will also mean hotter temperatures heading into midweek, with very low chances for organized thunderstorms as the upper high across the southwest states extends it`s influence into the central and southern plains. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 635 PM CDT Fri Jul 7 2017 A stationary front will be the focus for widely scattered thunderstorms through mid evening, mainly affecting GCK terminal since it is closest to the surface front. Convection will be slow-moving along this front. A more organized round of showers and thunderstorms is expected late tonight, mainly after 06z, and will carry 3 hours of VCTS at all terminals for this anticipated activity. && .PRELIMINARY POINT TEMPS/POPS... DDC 67 89 68 97 / 60 20 20 10 GCK 65 91 65 98 / 60 10 20 0 EHA 64 94 66 97 / 50 10 20 10 LBL 66 94 68 98 / 50 10 20 10 HYS 63 88 67 97 / 50 20 20 0 P28 70 88 70 96 / 70 30 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Umscheid
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1020 PM EDT Fri Jul 7 2017 .UPDATE... Issued at 1020 PM EDT FRI JUL 7 2017 Storms are continuing to deteriorate with loss of daytime heating late this evening. Still have a few SPS worthy cells, mainly from gusty winds between 30 and 40mph. Otherwise, nothing severe is expected. As such, went ahead and dropped our watch as of 10pm. A new forecast package, including HWO, was issued to remove watch wording. Also made some minor tweaks to the forecast to make sure the latest observations for temps, dew points, and winds were reflected in the near term forecast. So far Pops are actually behaving quite well, but will continue to monitor as this line slowly sinks south and will update timing as needed. All updates have been published and sent to NDFD/web. UPDATE Issued at 820 PM EDT FRI JUL 7 2017 Based on the latest radar trends with this defined line continuing to drop southward, went ahead and updated pops through the first part of the night to better reflect the expected trends. Also incorporated some the HRRR data for the projected forecast as it seems to be initializing well at this point. All changes have been published and sent to NDFD/web. This shouldn`t cause much change in the forecast package so do not need to reissue at this time. UPDATE Issued at 742 PM EDT FRI JUL 7 2017 A fairly well defined line of showers and thunderstorms has formed across southern Ohio and southern IN and is now quickly pushing southward towards our northern CWA. Pops are actually timed out quite well for the onset, but will have to monitor as it starts moving across our area in case any timing updates need to be made. Otherwise grids are in good shape. Just freshened up the near term forecast for the temps, winds, and dew points to make sure it was on track with the current observations. All changes have been saved and sent to NDFD/web. Also a new forecast package and HWO were sent out earlier to account for the Severe Thunderstorm Watch issuance. && .SHORT TERM...(This evening through Saturday night) Issued at 334 PM EDT FRI JUL 7 2017 A cold front will pass southeast across the area tonight and early Saturday morning. In advance of this front, multiple lines of thunderstorms have formed well to our north and a plethora of outflow boundaries are dropping south toward the Ohio River. These boundaries are serving as a focus for additional storms forming in advance of the established lines. Overall, have PoPs ramping up quickly beginning about 6 pm north of I-64 and continuing to work southward to about the Mountain Parkway by around 10 pm or so. The greatest instability and severe weather threat will lie to the north of the Mountain Parkway. South of the Parkway, dewpoints drop off into the 60s. Plus, storms will be moving southward into this area late in the evening, when instability is waning, so the severe weather threat will diminish the further the storms move south. Fog and stratus will again plague the area late tonight into Saturday morning. However, believe that stratus will dominate and will only advertise patchy fog at the surface. Overnight lows will only fall to around 70. Drier air will slowly filter in behind the front on Saturday but will leave in a small threat for a shower or storm right along the TN and VA borders. The vast majority of the forecast area will be dry, with plenty of sunshine by afternoon. Temps will warm into the low 80s, and then tumble into the refreshing upper 50s to low 60s Saturday night. .LONG TERM...(Saturday night through Thursday) Issued at 335 PM EDT FRI JUL 7 2017 The models remain in good agreement aloft through the majority of the extended portion of the forecast as they continue to evolve to show more eastward progress to the persistent western ridge. As this happens the broad eastern trough, extending south through the Great Lakes, will start to retreat allowing heights to gradually rise through mid week. This development will support a track for energy packets to ride past to the north of Kentucky in northwest flow. The model spread does increase through the week, though, so confidence in any specific solution or wave track is lower than average. Nevertheless, the rising heights should peak over the forecast area on Thursday - stronger in the ECMWF than the GFS with the CMC in between. Heights look to decline a bit over Kentucky to close out the week as the model consensus shows the ridge retreating back to the west and the eastern trough reinvigorated by energy pouring down through the eastern Great Lakes. Given the model agreement through mid weak, and greater uncertainty thereafter, will favor a blended solution throughout. Sensible weather will feature a good warm up for the week with humid conditions in place. In this environment, periodic storms will be possible - mainly driven by intrusions from any MCS activity to the north. The ECMWF seems too aggressive with a sfc wave moving through Kentucky later Thursday given the upper pattern so have discounted it in favor of the GFS solution. The models are in better agreement concerning convection for Friday as a boundary attempts to push south through the state. Similar to yesterday have made mainly terrain based adjustments to the lows each night from the SuperBlend given the pattern and favorable conditions for inversions to set up after sunset. Also adjusted the PoPs to better capture the diurnal nature of the showers and storm threat through the period. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) ISSUED AT 751 PM EDT FRI JUL 7 2017 While VFR conditions are currently in place across the TAF sites, this will quickly change over the next few hours. A large line of thunderstorms is quickly diving southward from southern IN and southern OH, making its way across the northern portion of the state. Tried to time out this line into the individual TAF sites, though some modifications may need to be made to the southern TAF sites as we see how fast it progresses through the state. SYM will be the first affected, likely before 1Z. With this line expect a quick drop in visibilities and CIGS, torrential rains, gusty/strong winds, as well as potential for hail. The threats will lesson significantly as it moves southward throughout the evening, and may not cause as much impact by the time it reaches KSME and KLOZ. In the wake of this initial line, expect another couple of hours of steady rainfall, followed by lingering llvl clouds and fog potential overnight. IFR conditions are possible for late tonight, either by fog or by low ceilings. This will slowly dissipate throughout tomorrow morning as high pressure begins to move into the region. For the rest of the day tomorrow, look for light winds and clearing conditions, with a sct fair weather VFR CU deck expected by afternoon. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JMW SHORT TERM...ABE LONG TERM...GREIF AVIATION...JMW
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
622 PM CDT Fri Jul 7 2017 .SYNOPSIS... Issued at 303 PM CDT Fri Jul 7 2017 H5 analysis this morning had a high pressure over the four corners with a ridge extending north into the Yukon and central Alaska. West of this feature, a closed low was present over the Gulf of Alaska, while east of the ridge, a closed low was located off the northern tip of Quebec. A trough of low pressure extended south into the Great Lakes and Mid-Atlantic. On the northern periphery of the high, a weak shortwave tracked across western and central Nebraska this morning and brought isolated showers and thunderstorms to portions of central Nebraska. Very little in the way of rain fell with the showers this morning as they tracked to the southeast. A second wave was located mid day across Montana and was approaching sern Montana and the Black Hills. At the surface, a stationary front was anchored across central Kansas and transitioned west into Colorado where it turned north along the front ranges of Colorado and Eastern Wyoming. Light easterly winds and much cooler temperatures were present across western and north central Nebraska this afternoon. Readings as of mid afternoon were in the 80s to lower 90s. && .SHORT TERM...(This evening through Saturday night) Issued at 303 PM CDT Fri Jul 7 2017 Tonight through Saturday night: Thunderstorm chances is the main forecast concern over the next 24 to 36 hours. for tonight: The disturbance, currently over Montana, will continue to slide to the southeast this evening. Based on the latest HRRR, convection will initiate in the Black Hills, entering the northern panhandle sometime around 00z this evening. Shear parameters remain favorable for super cell thunderstorms with weak southeasterly and easterly winds at the surface and northwesterly mid level winds. With respect to the severe threat, it will be highly conditional on whether or not convection can initiate over the black hills and nern Wyoming over the next couple of hours. The HRRR does initiate it and lift it sewd into the forecast area, but this is the only model which does develop decent convection this evening. The NAM12, GFS, and WARW initiate only a small amount of thunderstorms if any at all. Right now, I do have a mention of thunderstorms in the western and southwestern forecast area this evening which will suffice if the HRRR were to verify. Will keep the mention in the 20 to 30 percent range as it should be isolated in coverage at best. For Saturday, the short range solutions stall out a frontal boundary from the northeast to the southwestern portion of the forecast area. Moisture will pool along the boundary with SB CAPES reaching 2000- 3000 J/KG by mid afternoon Saturday. This is along and south of a line from O`Neill to Imperial. Have introduced pops across the forecast area Saturday afternoon into the evening hours INVOF the front. The only place I feel confident in a dry forecast ATTM is in the northwestern CWA. Elsewhere, have posted some 20 to 30 pops during the late afternoon and early evening hours INVOF the front. Shear will once again remain favorable for super cell thunderstorms, so cannot rule out the threat for severe storms Saturday afternoon/evening. .LONG TERM...(Sunday through Friday) Issued at 303 PM CDT Fri Jul 7 2017 Mid range (Sunday through Monday): On Sunday, a weak frontal boundary, will once again set up across the forecast area and serve as the focal point for thunderstorms. Both the NAM12 and GFS solns, develop convection in the vicinity of the front Sunday afternoon/evening. The main difference is location with the NAM12 favoring central and southern portions of the forecast area while the GFS favors northern areas. With a compromise between the two solutions, placed the front across the central CWA as well as the highest pops, albeit slight chances. Deep layer wind shear is much weaker on Sunday, so storms should be fairly weak and limited to the late afternoon/early evening hours. On Monday, the frontal boundary will lift north as a warm front. Very warm air will push into the forecast area from the southwest. With the front north of the area, temperatures will soar to the century mark across western and north central Nebraska. The latest mex guidance has temps well above 100 degrees across the region Monday and this looks on track given where the front is located. Monday night through Friday: Hot temperatures will continue across western and north central Nebraska into next week. Persistent ridging aloft will remain entrenched across the intermountain west and high plains well into the end of next week. There will be a limited threat for thunderstorms during the peak heating times of each day as weak shortwaves rotate around the northern periphery of the closed low. Pops were limited mainly to the late afternoon and evening hours in the outer periods, as little or no model agreement exists for precipitation. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 622 PM CDT Fri Jul 7 2017 It is believed the convection across Wrn Neb will grow upscale this evening and move south...generally tracking west of highway 83. Other thunderstorms...currently across Wrn SD...will move south through Wrn Neb tonight...also affecting areas west of highway 83...and exit Swrn Neb by 12z. The forecast uses a blend of the HRRR and RAP models. The thunderstorm coverage shown in those models was shifted west about 50 miles to line up with the ongoing thunderstorm activity. Other storm activity...generally isolated...is expected across Wrn/Ncntl Neb, 18z Saturday aftn-00z Saturday evening. The experimental HRRR model was the basis for this forecast. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Buttler SHORT TERM...Buttler LONG TERM...Buttler AVIATION...CDC
Area Forecast Discussion
National Weather Service Louisville KY
809 PM EDT Fri Jul 7 2017 ...Forecast Update... Issued at 808 PM EDT Fri Jul 7 2017 Storms across Indiana and Ohio are congealing into a QLCS as they drop to the south. Best theta-e ridging is to the west where new cells have been sprouting above pool of 70-75 degree dew points ahead of the advancing cold front. Still plenty of surface instability and sufficient shear ahead of the storms. However mid-level lapse rates are not very steep and AMDAR soundings out of SDF show some possible capping. Radars show that the storms are becoming outflow-dominated, and mesoanalysis shows CIN beginning to increase as the sun sets. So while storms are expected to continue their southward push into Kentucky, severe chances should slowly start to diminish as the evening progresses. .Short Term (Now through Saturday Night)... Issued at 220 PM EDT Fri Jul 7 2017 ...Strong to Severe Storms More Likely Late This Afternoon and Evening... Still on track for strong to severe storms to come through at least our northern zones, south central IN, north central KY, late this afternoon to this evening. How fast the line pushes southward will determine how far south that threat gets, as we start to lose daytime heating. As of this writing, it still looks like 4-8 is the prime period for southern IN, 6-10 for north central KY, and 10-2 AM for south central KY. Airmass ahead of these storms will have plenty of energy to give. Latest RAP analysis has CAPEs around 3000 J/kg with Downdraft CAPES in the 1500-2000 J/kg range...likely because of some mid-level dry air ahead of the line. A timely special sounding from ILN, at 18Z and ahead of the outflow boundary in OH, indicates 4000 CAPE, though quite a bit of dry air, 1.2 inch precipitable water. Based on wind shear, expect supercell structures still are possible as elements within the lines of storms dropping down from the north, and cannot rule out an isolated tornado, but the main threat will be damaging wind gusts with some hail. A little similar to last night, behind the rains we may have to deal with some patches of fog. Unlike last night though, the cold front may bring slightly more winds to keep us better mixed. We may have a few pockets of dense fog, but do not think it will be as widespread as this morning. Northwest surface winds Saturday will bring in drier and cooler weather. Still looking at temperatures below normal. With high pressure right over us Saturday night, we should see temperatures cool into the 50s in some locations. .Long Term (Sunday through Friday)... Issued at 220 PM EDT Fri Jul 7 2017 Nice weather will continue for Sunday, though after a cool start, we should warmup to a little warmer than Saturday. A few models continue to hint at some precip getting into southern IN late Sunday afternoon, possibly as a result of a weak warm front lifting north over the region or just as a result of instability in the warming airmass. Superblend came in with dry pops for the day period and slight chances in the north Sun. night. Overall synoptic pattern for the next work week will have ridging out west and northwest flow over the Midwest/Ohio Valley. Small disturbances riding within this flow will determine our rain chances through the week as well as temperatures. Models have a difficult time resolving these systems, which can either pass by to our north in the morning, but leave outflow boundaries for afternoon storms to focus on, or blast the system through here, bringing morning storms and drier but cloudy afternoons. Will continue the practice we`ve had over the last few days of capping the blended model rain chances in the chance range because of this uncertainty. One thing we have some confidence in is we`ll be back to a humid pattern again, so any days that do warm up significantly we could see heat indices get into the mid/upper 90s. && .Aviation (00Z TAF Update)... Issued at 717 PM EDT Fri Jul 7 2017 Storms over Indiana will drop south and cross the SDF and LEX airfields this evening. These storms may pack a wallop with strong gusty winds, very heavy rain, and small hail. Things will calm down behind the storms, with some patchy fog possibly developing toward morning. Quiet weather for the weekend. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........13 Short Term.....RJS Long Term......RJS Aviation.......13
Area Forecast Discussion
National Weather Service Miami FL
742 PM EDT Fri Jul 7 2017 .AVIATION... VFR expected to prevail at all terminals through Saturday morning with mainly light and variable winds. Southeasterly flow around 10 kt will resume late saturday morning, then another round of thunderstorms will develop in the vicinity of the terminals. Best chances of MVFR periods under heavy rain and low CIGS saturday afternoon remain over APF. .PREV DISCUSSION... /issued 703 PM EDT Fri Jul 7 2017/ UPDATE... Right on schedule, the convection continues to diminish across the peninsula. Winds will become light and variable overnight with light southeast winds along the east coast. Short term models indicate a few showers with possibly some embedded thunderstorms developing during the late night over the Atlantic. These storms may drift westward, towards the east coast metro. In the update, upped PoPs in this region to account for the possible showers. Otherwise, besides loading in the latest wind guidance, all other variables appeared on track. PREV DISCUSSION... /issued 422 PM EDT Fri Jul 7 2017/ DISCUSSION... Latest IR imagery from this afternoon shows broad troughing over the Ohio Valley and elongated upper level high pressure aloft dominating South Florida. The MFL RAOB sounding from this morning indicated a rather unstable atmosphere, due to slightly colder than normal 500 mb temps. With over 3500 J/KG and no capping inversion, the atmosphere was primed for active convection. Scattered thunderstorms initiated along the sea breeze boundaries during the early afternoon and have since been propagating inland, following outflow boundary collisions. Short term models, including the HRRR and Hi- Res WRF, show convection drifting back towards the coasts, propagated by the outflow boundaries from ongoing storms. By evening, with the loss of diurnal heating, guidance diminishes this activity. Overnight, light east and southeast flow will shift the threat of showers and thunderstorms to over the Atlantic waters. A few of these showers may affect the east coast metro region through mid morning, but not expecting any widespread activity. This weekend through mid next week: The aforementioned strong 500 mb high will edge slowly northeast towards Bermuda, generating a more south southeast flow for South Florida. Deeper moisture will be allowed to advect northward with GFS forecast PWAT values rising to generally between 1.75"-2.00" on Saturday. A very similar synoptic pattern will take shape from Sunday through mid next week. Thus, expecting typical summerlike weather to ensue. High pressure near Bermuda will create east or southeast flow across the peninsula with mainly diurnally driven thunderstorms. Most convection will form along the sea breeze, then push toward the interior and Gulf coast during the afternoon. The main threats with these storms will be frequent lightning, brief heavy rain, and gusty/erratic wind gusts. During the nights, showers and isolated thunderstorms will rumble over the Atlantic waters and adjacent east coast metro region. Through the period, temperatures will remain near average for this time of year. Maximums will be near 90 with minimums from the mid 70s in the interior up to near 80 along the east coast. MARINE... Prevailing east-southeast winds around 10 knots will continue across the South Florida waters into early next week as high pressure remains to the north of the region. Both the Gulf and Atlantic seabreezes are expected to develop each afternoon, leading to locally higher winds near the coast. Isolated to scattered showers and thunderstorms are possible each day, with locally higher winds and seas as well as lightning near any thunderstorms. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 77 90 77 90 / 30 40 30 40 Fort Lauderdale 80 91 79 90 / 30 40 30 30 Miami 79 91 78 91 / 30 40 30 40 Naples 76 90 75 89 / 20 50 40 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && AVIATION...17/AR
Area Forecast Discussion
National Weather Service Marquette MI
730 PM EDT Fri Jul 7 2017 .SHORT TERM...(This evening through Saturday) Issued at 406 PM EDT FRI JUL 7 2017 WV imagery and RAP analysis indicated an amplified pattern with a prominent mid/upper level ridge from the sw CONUS into Alberta/BC and a broad trough over the ne CONUS resulting in nw flow through the nrn Great Lakes. A shortwave trough supported an area of shra/tsra over nw WI that was diving quickly to the se. Heating also great enough this afternoon to boost MLCAPE values above 500 J/Kg over the srn cwa so that isold shra/tsra also have developed over srn Menominee county. Otherwise, stable air off of Lake Superior has kept skies clear over the ern cwa while sct-bkn cu dominated inland over the west. Tonight, any shra/tsra that develop near the WI border late this afternoon should diminish early this evening as the shrtwv slides out of the area. The influx of much drier air, clearing skies and diminishing winds will allow temps to drop into the upper 40s and and lower 50s. Saturday, another mid level shrtwv and cold front will drop toward the nrn Great Lakes resulting in increasing wrly winds along with moderate WAA. Sunshine and mixing to around 750 mb will push temps into the upper 70s. High based afternoon cu will develop as dewpoints remain aob 50F. Any chances for shra/tsra with the front will arrive mainly after 00z over the far north near P59. .LONG TERM...(Saturday night through Friday) Issued at 347 PM EDT FRI JUL 7 2017 High amplitude ridging will remain in place for the Northern Rockies, through at least Mon, allowing heat to build across the Central/Southern Plains. Downstream of the ridge will be a persistent trough over Hudson Bay, which will translate into a cool/seasonal northwest flow for the Great Lakes region and especially the Upper Peninsula of Michigan. Ensembles begin to indicate good agreement that the ridge upstream will begin to relax/flatten Tue, with the flow transitioning towards a quasi- westerly orientation. This will allow surface temps to slowly return to slightly above climo. Operational solutions continue to indicate a frontal boundary sliding southeast across the forecast area Sat eve/overnight, but given the lack of a push behind the boundary, the front will get hung-up and continue to keep a chance for precip around into Sun. With cooler air aloft, any heating during the day Sun would likely be warm enough to produce an isolated thunderstorm. Then weak surface ridging will bring some drier air to the Upper Peninsula for Mon, but this feature will be short-lived as the flow begins to flatten and guidance progs a shortwave to arrive Wed/Thur. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 729 PM EDT FRI JUL 7 2017 Expect VFR conditions through the forecast period at all TAF sites. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 406 PM EDT FRI JUL 7 2017 Southwest winds will gust up to 25 knots over central Lake Superior on Saturday. Otherwise, winds should remain tranquil through the forecast period with winds staying below 20 knots. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...Beachler AVIATION...Voss MARINE...JLB
Area Forecast Discussion
National Weather Service Paducah KY
632 PM CDT Fri Jul 7 2017 .UPDATE... Updated aviation section for 00z taf issuance && .SHORT TERM...(Tonight through Sunday night) Issued at 107 PM CDT Fri Jul 7 2017 Near term meso plot shows FA abounds in heat/moisture, with surface dew points uniform in lower half of 70s. This heated and moistened airmass is in place ahead of approaching cold front, seen by wind shift extending across ncntl IL. Visible imagery shows benign CU much of FA, but some agitation in CU field is seen just along northern periphery. Radar mosaic depicts echoes along/ahead of the front, as close as northwest IN, around Lafayette, with its southwestward trail struggling to coalesce into echo returns in IL. This is the area to watch for near term development (next 1-3 hrs), per latest swomcd. HRRR has been modeling convection nicely, and it breaks/brings development to our northern counties around 22-23Z, then dives it southward across much of remainder of FA thru 06z. Most action is sustained in our northeast quad, per latest SWODY1. Increasing winds aloft, and steepening mid level lapse rates, will mean wind/hail as the primary strong to severe storm hazards, with ltg/heavy rain also convective hazards. We have noted the HRRR trending a little later for initial development, by 1-2 hours, since the beginning of the shift, so that`s something we`ll adjust for in the grids as well. After fropa, should see those drier dew points start to work in tmrw, providing a welcomed respite to the early July heat/humidity. Dew points should be falling into the low to mid 60s, and more or less staying there, thru the remainder of the weekend. We think Pops will likewise stay outside the confines of the FA, with Highs in the 80s/Lows in the 60s. .LONG TERM...(Monday through Thursday) Issued at 323 PM CDT Fri Jul 7 2017 A southerly Gulf fetch will be in place for most of next week. This will be conducive to gradually increasing surface dewpoints and overnight lows, while highs should level off around 90 degrees, though there were some model indications of possible higher temps. Cloud and pcpn coverage may keep a lid on them however. Dewpoints in the lower to middle 70s will cause heat indices to flirt with 100 mainly Wed and Thu. The medium range models were in reasonable agreement depicting the overall mid level flow pattern over the CONUS. However, by mid week, the Canadian showed extensive deep moist convection across the PAH forecast area, unlike the GFS/ECMWF, which were much drier. All the models showed an initially somewhat amplified western ridge/eastern trof pattern gradually flattening as the western ridge expanded eastward. Meanwhile, a wavy west-east surface boundary is progged to linger across the Midwest (just to the north of our area) during the extended forecast period. This boundary will be the trigger for shower and tstm development in the moist and unstable environment, some being of the MCS variety, especially during the heating of the day. The model blend continues to show somewhat inconsistent "spotty" pcpn chances from time to time through the period. Currently, it appears that most of the pcpn will remain to the north of the PAH forecast area until perhaps later in the week when some northern stream shortwave energy begins to impinge on the broad mid level ridge over us. Bottom line is, while pcpn may occur during the extended period, the coverage and, to a lesser extent, the timing of the pcpn is quite uncertain. && .AVIATION... Issued at 632 PM CDT Fri Jul 7 2017 A cold front was moving southeast into southern IL and southeast MO as of 23z. A couple lines of cumulus clouds have formed along the front, along with isolated intense thunderstorms. The front and its associated lines of isolated convection will move across the taf sites this evening. The tafs will be updated if storms appear imminent, but coverage appears too isolated to warrant a tempo group at this time. Winds will become northwest behind the front by 06z. Some mid or high clouds will follow behind the front, then mainly clear skies are expected on Saturday. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ AVIATION...MY
Area Forecast Discussion
National Weather Service Pocatello ID
152 PM MDT Fri Jul 7 2017 .DISCUSSION...A ridge of high pressure anchored over the Great Basin will continue to support above normal temperatures across the region through Sunday. Embedded moisture will help to fuel isolated to scattered mainly afternoon convection favoring the mountains each day. By Sunday, a low pressure system moving into WRN Canada will begin to break down the ridge as drier and increasingly stronger SW winds spread into the region Monday and Tuesday. With the trough passage will come slightly cooler temperatures and locally breezy conditions. And although the models are showing enhanced convection out ahead of the trough over the SE highlands Monday afternoon, the placement of this activity will be highly dependent on the progression and timing of the leading edge of the trough (so a bit early yet to make any definitive calls on that timing issue). By mid- week, the GFS is showing the ridge rebounding across the region with unseasonably warm temperatures and a return to isolated mainly afternoon convection favoring the mountains through weeks end. Huston && .AVIATION...Showers associated with a weak shortwave are pushing east of Idaho Falls and into Driggs as of 11 am this morning. This afternoon, we continue under the influence of the Southwestern Monsoon and its associated moisture field. High confidence on convective development in southeast Idaho, but less confidence in where it will initiate. Including VCTS at all sites this afternoon and evening. KBYI saw IFR vis in smoke this morning, and HRRR Smoke forecast supports the idea of smoke/haze posing a potential problem again tonight/tomorrow morning. Not enough confidence to drop vis below VFR. Hinsberger && .FIRE WEATHER...Hot temperatures continue under the dome of high pressure over the West. The influence of the Southwest Monsoon will stoke isolated afternoon and evening thunderstorms through Sunday. As we head into Monday, an upper disturbance will move onshore while a surface cold front appears to push through southeast Idaho Monday afternoon. Models support the idea of mid-level drying behind the cold front along with low surface RH. Some uncertainty remains on the timing of the frontal passage, and how much convection will be triggered by it. Thunderstorm coverage is still expected to be isolated, but may increase along the cold front. Wind gusts of 25 to 30 mph are possible Monday and Tuesday afternoon in the Snake Plain and Central Idaho Mountains in response to the tighter pressure gradient. The greatest threat to potential Red Flag conditions in those areas will be Monday and Tuesday due to the wind gusts and low RH expected, though confidence is not strong enough to warrant headlines just yet. Hinsberger && .HYDROLOGY...Warm temperatures will continue across the region while many of the rivers remain steady or fall. Significant backcountry flood issues continue to impact roads, bridges, and trails in the Sawtooth National Forest above 7500 feet MSL where district rangers have requested that the Small Stream Areal Flood Warning continue. Further south, along the Big Wood River, river levels remain well below the established flood stage, however significant changes in the river channel have left several homes along War Eagle Drive west of Hailey and along Gimlet Road 4 miles south of Ketchum experiencing ongoing flood issues. Emergency management officials were in agreement that the flood advisory would be allowed to expire. Huston/Wyatt && .PIH WATCHES/WARNINGS/ADVISORIES...None. && $$
Area Forecast Discussion
National Weather Service Phoenix AZ
448 PM MST Fri Jul 7 2017 .SYNOPSIS... Increasing moisture will lead to a gradual cooling trend through the weekend. Chances of thunderstorm activity will also increase in central and eastern Arizona through the weekend. Moisture will persist through next week continuing thunderstorm chances for the mountains and deserts of Arizona. && .DISCUSSION... The Four Corners` version of the ring of fire is evident on satellite, with convection and cooler clouds tracing out the anticyclonic flow around the Monsoon high. Morning PSR sounding registered a record 500 mb height of 595 dam. At the surface, temperatures have soared with Phoenix already breaking the daily record high of 115 degrees, set more than 100 years ago in 1905. Latest consensus amongst the hi-res WRFs is for isolated to scattered storms to affect the higher terrain north and east of Phoenix this afternoon before dropping into the valley later this evening. Although total precipitable water is only around the 50th percentile, a well-defined outflow boundary propagating out of the northeast should help to provide the lift needed to initiate isolated storms across the lower deserts. PoPs were increased across mainly south-central Arizona, with higher weight given to the latest SREF and NBM. CAMs including the latest HRRR continue to suggest that areas from Phoenix northward will see the greatest coverage of storms, however just about anywhere within Maricopa and Pinal counties stand to potentially see some impact. Trajectory is also less than ideal for a dust storm, though areas of dust with reduced visibilities, particularly over the Salt River Indian Community cannot be ruled out. && .PREVIOUS DISCUSSION... Increasing Monsoon moisture will become more notable by Saturday, as PW values during peak mixing should easily exceed 1 inch across most of the lower deserts. The midlevel cyclone positioned to the north will weaken, but still maintain general easterly flow across Arizona/New Mexico. Timing of individual perturbations and the potential for any debris cloudiness will affect the evolution of thunderstorm development each day, but the atmosphere is becoming primed in typical Monsoon-fashion for a more convectively active period through next week. This will also bring a welcome reprieve from the excessive heat, given the increased levels of moisture and potential for more abundant cloudiness. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Showers and storms continue to build over the mountains north/east of Phoenix. Some cells showing better structure over the Superstition Mountains east of PHX. Not confident enough that any TS will happen near/over any terminal to include mention at this time but will monitor for updates. Still expecting outflow winds this evening from the N/E, not an ideal location for dust. Will update TAFs as timings change/confidence improves. BKN clouds will remain overnight and more showers/storms expected tomorrow. Southeast California/Southwest Arizona including KIPL and KBLH: Westerly winds will quickly switch to breezy southerly winds during the early morning hours Saturday as a surge of gulf moisture/air pushes into the lower deserts. That flow will dominate through much of the say Saturday. Small chance winds will produce some reductions in visibility due to dust, especially in the Yuma area. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Sunday through Thursday: An upswing in monsoon moisture levels from Sunday into early next week to bring an increase in thunderstorm activity and chances for wetting rains to the region, especially to the higher terrain north and east of Phoenix. Along with the better chances for rainfall, cooler temperatures can also be expected, with highs falling to near normal values. Some decrease in convective activity is possible for the middle of next week as slightly drier air moves into the region. Minimum humidities to fall into the 15-30 percent range each day, with fair-good overnight recoveries. && .CLIMATE... Record highs this week: Date Phoenix Yuma ---- ------- ---- 7/7 115 in 1905 117 in 1942 && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Excessive Heat Warning until 8 PM MST /8 PM PDT/ this evening for AZZ530>556-559>562. Heat Advisory until 8 PM MST this evening for AZZ557-558-563. CA...Excessive Heat Warning until 8 PM PDT this evening for CAZ561- 562-564>570. && $$ Visit us on Facebook, Twitter, and at weather.gov/phoenix DISCUSSION...Hirsch PREVIOUS DISCUSSION...Rogers AVIATION...Iniguez FIRE WEATHER...Percha ClIMATE...Wilson
Area Forecast Discussion
National Weather Service Tulsa OK
931 PM CDT Fri Jul 7 2017 .DISCUSSION... Isolated showers and thunderstorms continue to develop this evening in the vicinity of a weak frontal boundary that is sagging south into the area. The latest runs of the HRRR suggest that this activity may fester much of the night near the boundary. Have adjusted pops some based on observed and expected conditions overnight, with the rest of the forecast looking good at this time. Update on the way. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...14 LONG TERM....05 PLATE
Area Forecast Discussion
National Weather Service Tucson AZ
245 PM MST Fri Jul 7 2017 .SYNOPSIS...Isolated showers and thunderstorms mainly north to west of Tucson ending around midnight. The coverage of showers and thunderstorms will increase starting Saturday, then scattered mainly afternoon and evening thunderstorms will prevail during the upcoming week. && .DISCUSSION...An isolated shower developed around 2 pm MST near the international border south of Sells. Other isolated showers were developing at this time across the White Mountains. The 07/12Z Univ of AZ WRF-NAM has the showers near the international border well handled, while the 07/12 Univ of AZ WRF-GFS and several HRRR solutions depict the White Mountain showers nicely. At any rate, given the high-resolution model solutions, have maintained isolated to scattered showers and thunderstorms this evening from the White Mountains extending north-to-west of Tucson, or into southern Pinal County and western/central Pima County. Dry conditions will prevail this evening south-to-southeast of Tucson. The bulk of any showers/tstms should end by midnight, but have maintained a slight chance of showers/tstms late tonight across the White Mountains. Various NWP solutions suggest fairly similar coverage of showers/tstms to occur Saturday afternoon and evening versus this afternoon/evening. Thereafter, a fairly substantial increase in coverage of showers/ tstms should commence Sunday afternoon and evening, at least if the 07/12Z Univ of AZ WRF-NAM and WRF-GFS, the 07/12Z ECMWF, and to some extent the 07/12Z GFS are close to reality. High pressure aloft is progged to be centered near the Four Corners region, and increased lower level moisture in combination with favorable steering flow should promote generally scattered coverage of showers/tstms. Thus, Sunday afternoon and evening should be the best period for showers/ tstms for much of the Tucson metro area so far this season. Scattered mainly afternoon/evening showers and thunderstorms are forecast to continue during much of the upcoming week. The best chance of measurable rainfall on any given day will favor locales east of Tucson, and lower precip chances occur west of Tucson. However, the daily detail, or nightly detail for that matter, will certainly be subject to revision with subsequent forecasts. High temperatures Saturday will be about 5-8 degrees or so lower from Tucson westward versus temps achieved this afternoon. Highs Saturday east of Tucson will be just a couple of degrees lower versus this afternoon. Daytime high temperatures Sunday into next Friday will then average quite close to seasonal normals given the increased moisture and precip chances. && .AVIATION...Valid thru 09/00Z. Isolated -TSRA/-SHRA from the White Mountains northeast of KSAD extending north-to-west of KTUS into this evening. Most -TSRA/-SHRA will dissipate by midnight. Isolated to scattered -TSRA/-SHRA will occur Saturday afternoon. Otherwise, VFR conditions with surface wind sely to nely 8-18 kts and gusts near 25 kts into Saturday morning, then surface wind sly to sely 5-15 kts Saturday afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect isolated thunderstorms this evening from the White Mountains northeast of Safford extending north-to-west of Tucson. Dry conditions should prevail across Cochise County and also likely dry conditions continuing for the Tucson metro area. However, a slight chance of thunderstorms continues for the Catalina/Rincon Mountains. The bulk of thunderstorms will end by midnight. The coverage of showers and thunderstorms will increase starting Saturday, then scattered mainly afternoon and evening thunderstorms will occur during the upcoming week. The prospect of more significant rains should also increase as the week progresses. Expect brief strong, gusty and erratic winds due to thunderstorm outflows. Daytime temperatures will also moderate closer to seasonal normals next week. && .TWC WATCHES/WARNINGS/ADVISORIES... Excessive Heat Warning until 7 PM MST this evening for AZZ501- 502-504-505. && $$ Francis Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson