Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/05/18

Area Forecast Discussion
National Weather Service La Crosse WI
659 PM CDT Wed Jul 4 2018 .UPDATE... Issued at 659 PM CDT Wed Jul 4 2018 The severe weather threat had exited the area for this evening. Some rises are possible on areas streams as heavy rainfall from storms today makes its way into the river systems. Additional storms are possible later tonight mainly south of Interstate 90 but any severe weather should stay south of the area. && .SHORT TERM...(This evening through Thursday) Issued at 317 PM CDT Wed Jul 4 2018 Main focus is on short term convective potential. Storms have been slowly increasing this afternoon in the vicinity of a convectively generated MCV over southern MN and northenr IA and remnant outflow boundary farther north and east. Ample instability is in place with RAP analyses showing MLCAPE of 2500 to 3500 J/kg from southeast MN into northeast IA and western WI ahead of the rain-cooled outflow air. 0-6 km and 0-3 km shear are lacking with the stronger flow displaced well north. However, given the instability and the boundaries/MCV to help aid organization, a window for a few strong to severe storms will exist this afternoon into early evening. Still expect damaging winds and heavy rain to be the primary hazards given very warm temps aloft, but some hail is possible. Given this evolution, confidence is decreasing in strong or severe storms later this evening and tonight with the approach of the main cold front and upper shortwave trough sliding off to the north in the wake of the afternoon storms. Did keeps some lower end shower/storm chances going, but it is possible that many areas will end up dry for evening activities. Will trim the northern and western edge of the Heat Advisory but keep it going farther to the south and east at this time. Drier and cooler air will work in on Thursday behind the front on Thursday although a few showers or storms could persist into the morning. .LONG TERM...(Thursday night through Wednesday) Issued at 317 PM CDT Wed Jul 4 2018 Much quieter weather is expected late this week into the weekend with broad surface through mid-level ridging in place. A shortwave trough passing across southern Canada Sunday and Sunday night may drag a surface boundary south into the area, but right now confidence in showers/storms is low. Otherwise, surface ridging will remain in place into early and middle of next week with southerly flow helping to bring warmer air back into the area. Temps will gradually warm from the upper 70s to mid 80s Friday and Saturday into the 80s to perhaps low 90s by the middle of next week. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 659 PM CDT Wed Jul 4 2018 VFR conditions are expected at the TAF sites. Isolated showers and possibly a thunderstorm cannot be ruled out tonight but the bulk of this activity should stay south of the TAF sites. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ UPDATE...Wetenkamp SHORT TERM...JM LONG TERM...JM AVIATION...Wetenkamp
Area Forecast Discussion
National Weather Service Burlington VT
754 PM EDT Wed Jul 4 2018 .SYNOPSIS... Hot weather will continue through Thursday as strong high pressure remains across the area. The chances of showers and thunderstorms increase later Thursday afternoon into Friday morning as a cold front crosses the area. Behind this front, cooler, more seasonal temperatures are expected for the upcoming weekend. && .NEAR TERM /THROUGH THURSDAY NIGHT/... As of 650 PM EDT Wednesday...Another hot day across the North Country with BTV hitting 95 degrees and atop Mount Mansfield tying their all time record high temp of 84 degrees again. However, dewpoints currently in the mid 50s to lower 60s has resulted in cooler heat index values in most areas, but have jumped into the l/m 60s per the 7 PM, with a 70 dewpoint at mss. As sfc high pres shifts to our east tonight, south/southwest winds just off the deck at 10 to 15 knots will help advect deeper moisture back into the North Country overnight. Soundings show bl dewpoints increasing quickly after sunset tonight into the 60s with some values approaching 70 degrees across the SLV and CPV by sunrise on Thursday. The airmass will become very muggy again with heat advisory looking good for Thursday. Latest rap does show some potential for mixing of slightly drier air aloft toward the sfc, which should keep values below the readings experienced on Sunday. Otherwise, a very quiet and warm night expected with lows ranging from the l/m 60s mountain valleys to lower 70s cpv/slv. Agree with previous forecaster thinking with regards to convection on Thursday aftn/evening. Looks like a classic pulse environment with high cape (2000 j/kg) and weak shear (0 to 6 km <25 knots) and limited forcing. Also, deep dry layer on soundings btwn 800mb and 500mb might limit areal coverage of convection. However, deep layer mixing thru 750mb with steep lapse rates and dcape values around 1300 j/kg, would support the threat for an isolated svr with damaging winds as the primary hazard, in the stronger more robust updrafts. SPC day 2 has most of our cwa in marginal risk, which looks reasonable given the expected pre- storm convective environment. Previous discussion below: Southwesterly return flow will develop over the region tonight as high pressure overhead shifts eastward and off the Atlantic Coast. This will allow us to tap into a warmer, higher humidity air mass currently over the Ohio River Valley. Thus, expect temperatures tonight to be quite a bit warmer than last night. The Champlain and Saint Lawrence Valleys will remain in the low to mid 70s, while the remainder of the CWA will bottom out in the mid to upper 60s overnight. As we pull in moisture in addition to the warmer air to our southwest, expect air to feel increasingly muggy overnight into tomorrow. As low pressure over central Canada shifts eastward Thursday, the pressure gradient will increase over New England, allowing for southwesterly flow to strengthen. Warm air/moisture advection will continue through the day ahead of an approaching cold front pushing east through the Great Lakes Region. Expect clouds to spread over the region from west to east through the day. Despite the cloud cover however, Thursday will be very hot and muggy. Temperatures will once again be in the low 90s in the Champlain and Saint Lawrence Valleys and upper 80s elsewhere. Dewpoints will be higher than today however, so heat indices will be in the upper 90s up to 100 during the afternoon hours. A heat advisory is in effect from noon to 8 PM Thursday for the Saint Lawrence Valley, western Champlain Valley of New York, and central and northern Vermont. During the day Thursday, some moderate instability will build in the atmosphere (MUCAPE values progged in excess of 2,000 J/kg), so could see some convective showers develop during the day as heights slowly fall ahead of the approaching trough. Forcing will be limited however, so not expecting widespread convection. Nonetheless, any showers that do develop will have plenty of moisture (Forecast PW values > 1.8") and warm air to work with, so could produce locally heavy rainfall and some gusty winds. As we transition to the overnight hours Thursday night, expect any convective showers/thunderstorms that have developed to weaken as we lose instability and the atmosphere becomes capped. However, attention quickly then turns to the approaching cold front, which will trigger more rain showers as it pushes through from west to east overnight. While we will have lost the better daytime instability, still will likely have some elevated instability to work with, so a few thunderstorms are not out of the question in the overnight hours. 0-6km bulk shear values between 20 and 40 kts could allow for some more organized storms to develop along the front, with the primary threats being locally heavy rainfall and some gusty winds. Once the front pushes through, we`ll finally usher in long awaited cooler, drier air from Canada, finally marking the end of this summer heat wave that will remain in the record books for a quite some time. && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... As of 331 PM EDT Wednesday...Relief from our heat wave finally arrives on Friday as a cold front crosses the North Country. This front will bisect the region from northeast to southwest Friday morning, separating the warm humid air to the south and cooler, drier air to the north. Showers and possible thunderstorms will likely be ongoing across eastern VT Friday morning ahead of the front, but these will quickly be shunted to the south and east by the afternoon as the front pushes into souther/eastern New England. Clearing will take place post-front, though expect we`ll see scattered cumulus lingering into the afternoon. Winds will turn to the northwest and become breezy behind the front, ushering in a much more comfortable airmass. Highs will be in the lower to mid 70s in the mountains, while the wider valleys will likely be in the upper 70s to around 80. Skies will clear out overnight, and with dewpoints in the 40s and 50s, expect it will be a very refreshing night after the prolonged heat and humidity. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 331 PM EDT Wednesday...It`s shaping up to be a beautiful weekend as high pressure crests directly over the area. This will lead to lots of sunshine and mainly light winds. Saturday will be the cooler of the two days with highs in the 70s areawide, while Sunday`s temperatures will top out around 80 in most locations. The next chance for rain arrives Monday into Monday night as a weak trough/frontal boundary sinks south out of Canada. This feature will hang around at least through Tuesday, keeping the threat of showers/thunderstorms in the forecast. Wednesday is a little more questionable as the GFS shows a ridge building in while the ECMWF has an upper low dipping right over the North Country. Have gone with just a slight chance of showers for now. Temperatures through the middle of next week will be a bit above normal with slightly muggier conditions than over the weekend, but not anything like what we`ve seen this week. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... Through 00Z Friday...Mainly VFR conditions through the period for most TAF sites...exceptions will be at KSLK/KMPV/KRUT where nearly calm winds at the surface and moisture advection overnight will provide conditions conducive for some MVFR fog development between 07-11z. Thursday winds will turn out of the south between 10-15 kt with gusts upwards of 20 kt later in the afternoon at all sites except KPBG which should remain with a SE lake breeze throughout much of the day. Afternoon thunderstorms may be possible across the area Thursday so have mention of VCSH at all TAF sites mainly after 18z. A cold front approaches from the west toward the end of this TAF period. Outlook... Thursday Night: VFR. Likely SHRA, Chance TSRA. Friday: Mainly VFR, with local MVFR possible. Chance SHRA, Chance TSRA. Friday Night: VFR. NO SIG WX. Saturday: VFR. NO SIG WX. Saturday Night: VFR. NO SIG WX. Sunday: VFR. NO SIG WX. Sunday Night: VFR. NO SIG WX. Monday: VFR. Slight chance SHRA. && .CLIMATE... Max Temp Records July 4th through 5th: Date KBTV KMPV K1V4 KMSS KPBG KSLK 07/04 98|1911 92|1983 100|1911 95|1949 95|1955 94|1921 07/05 98|1911 90|2010 99|1911 93|1949 97|2010 95|1928 && .BTV WATCHES/WARNINGS/ADVISORIES... VT...Heat Advisory from noon to 8 PM EDT Thursday for VTZ001>012- 016>019. NY...Heat Advisory from noon to 8 PM EDT Thursday for NYZ026>028- 035-087. && $$ SYNOPSIS...RSD NEAR TERM...RSD/Taber SHORT TERM...Hastings LONG TERM...Hastings AVIATION...LaRocca/RSD/Taber CLIMATE...WFO BTV
Area Forecast Discussion
National Weather Service Caribou ME
914 PM EDT Wed Jul 4 2018 .SYNOPSIS... A ridge of high pressure builds over the region on Thursday. A strong cold front will approach Thursday night and cross the area Friday morning. High pressure will bring cooler and drier air into the region late Friday into Saturday. && .NEAR TERM /THROUGH THURSDAY/... 9:14 pm update: One lone shower developed near Eagle Lake shortly after 8 pm, and it fell apart by 9 pm just west of Washburn. The shower never looked too impressive on radar with little reflectivity aloft. There are a few healthier looking showers showing up on MRMS just along and just west of the Saint Lawrence River. As the region remains on the periphery of a strong upper ridge, an isolated shower or thunderstorm could develop in situ or move into the area from the west/northwest. The best chance of a shower or thunderstorm the remainder of the night will be across northern Aroostook County, and mainly from 03-06Z. Made some tweaks to the forecast for the remainder of the night based on the latest observations and radar. Previous discussion: Humidity will be on the increase tonight into Thursday w/yet another hot day expected for Thursday. But before that, there is some hint at the potential for a couple of tstms this evening. Beach Hazard Statement will expire at 8 PM. The latest suite of mesoscale guidance including the RAP and HRRR have backed up on any convection until much later this afternoon into the evening. Dewpoints have been slow to increase so far today, but are still progged to increase over the next 3-4 hrs. The latest sfc analysis showed the higher dewpoints(mid/upper 60s) to the sw. As winds turn to a more ssw direction this evening and overnight, this will push those higher dewpoints ne. Low/mid level lapse rates will steepen and some moisture does look like it gets advected into the region. 0-6KM shear of 30 kts and inverted v-type sounding lends support for some strong downdrafts if storms can get going. Will keep mention of strong wind gusts for any storms. Activity should be done by midnight w/clearing. Some patchy fog is expected as well. Overnight lows will be in the 60s. For Thursday, heat index values are forecast to increase into the mid and possibly upper 90s, mainly away from the Bangor and Downeast region due to the ssw wind. Upper ridge looks like it builds over the region. The 12Z NAM/GFS show this well. Decided to go w/a Heat Advisory for the Central Maine Highlands and the Millinocket and Houlton region. Further n and w, readings look to be a bit cooler attm. This will need to be assessed by the later crews if the advisory needs to be expanded further n. Daytime temps are expected to be in the low to mid 90s w/the exception of the Downeast coast. As far as precip goes, it should be dry until later Thursday night. More on this in the medium range below. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... Thursday night will be warm and steamy ahead of an approaching cold front from Quebec. Lows Thursday night will likely not get out of the lower 70s in most places. The warm temperatures and dew points in the upper 60s to near 70 will result in a rough sleeping night for those without air conditioning. Coastal stratus is likely to be an issue as well, as southerly winds transport higher dew point air across the Gulf of Maine, resulting in low clouds and patchy fog for the coast. Expect a few showers and thunderstorms to develop across northwest Maine after midnight in advance of the approaching cold front. The cold front will cross far Northern Aroostook County and the St. John Valley shortly after daybreak Friday and then continue to push southeast off the down east coast by late afternoon. Shower and thunderstorms are expected to accompany the passage of the front on Friday. The early timing of the front will not be favorable for widespread severe weather. However, the best chance for any stronger storms would be across down east, do to the somewhat later timing of the front. Will not include any enhanced wording at this point and let midnight crew re-evaluate the threat. Did mention the chance for some heavier rain in any thunderstorms for central and downeast with pwat/s close to two inches. The cold front will be push offshore by sunset Friday. A much drier and cooler air mass is expected to overspread the region in the wake of the frontal passage Friday night making for much more comfortable sleeping weather. Lows by Saturday morning are expected to range from the upper 40s to near 50 north and lower 50s downeast. A large ridge of high pressure will build east from the Great Lakes region on Saturday. Expect partly/mainly sunny skies on Saturday. Highs will be in the low to mid 70s which is close to normal for this time of year. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... After the brief heat relief on Saturday, ridging between systems will again send temperatures above normal Sunday and Monday. Without the persistence of a large, nearly CONUS-wide ridge deflecting systems north, the heat won`t be as stagnant. Next system to impact Maine will be Monday afternoon overnight into Tuesday. 12Z GFS continues with a cold front solution exiting off the coast Tuesday morning. The CMC tries to replicate this but then develops a more progressive closed low compared to the ECMWF. Will keep these solutions in mind by lingering chance PoPs over northern areas. A lot of interaction occurs off the east coast depending how the front exits the region, which will have impacts on how progressive the early to mid-week system will be. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... NEAR TERM: VFR conditions are expected through Thursday at the terminals. SHORT TERM: VFR conditions are expected at the Aroostook County terminals Thursday evening. Scattered showers and thunderstorms are expected to develop across far northwest Aroostook County after midnight. Moisture advecting in off the coastal waters will result in low clouds and patchy fog with IFR or lower conditions late Thursday night at KBGR/KBHB. Widespread showers and the chance for thunderstorms can be expected on Friday as a cold front crosses the region. The front will reach KFVE shortly after daybreak and clear the down east coast late Friday afternoon. MVFR or lower conditions are possible in any heavier showers or thunderstorms on Friday, especially at KBGR/KBHB. Clearing skies and VFR conditions will develop from northwest to southeast in the wake of the frontal passage. VFR conditions are expected are expected Saturday through Tuesday. && .MARINE... NEAR TERM: No headlines expected into Thursday. Winds/seas will pick up to 10-15 kts by Thursday afternoon as winds go ssw. Seas are forecast to build to heights of 3-4 ft by late in the day on Thursday. SHORT TERM: Winds/seas could begin to approach SCA levels as we go into Thursday night and Friday in the southwest flow ahead of the approaching cold front. Visibility will be reduced to 1 to 3 NM in areas of fog Thursday night and in areas of fog, showers, and thunderstorms on Friday. Winds/seas will then remain below advisory criteria much of the remainder of the long term. && .CLIMATE... The high temperature this afternoon at Caribou was 90 degrees. This was the first 90 degree day since June 11, 2017. On average, Caribou averages one 90 degree day every other year; however, many years there are none, and some have a few to several days with a high of 90 degrees or warmer. The high of 90 this afternoon fell shy of the record high of 92 degrees, set in 1983. At Bangor, the high temperature this afternoon was 94 degrees. This was the warmest temperature observed since July 22, 2011. The high of 94 degrees today fell shy of the record high of 99 degrees, set in 1949. On average Bangor averages 4 days with a high of 90 or above each year. The last time there was a year without a 90 degree day was in 2014; and 1995 holds the top honors with a total of 23 days with a high of 90 or above. The record highs for tomorrow, 7/5 are: Caribou: 92F, set in 1983 Bangor: 95F, set in 1935 Houlton: 93F, set in 1983 and again in 2000 Millinocket: 92F, set in 1983 && .CAR WATCHES/WARNINGS/ADVISORIES... ME...Heat Advisory from 1 PM to 7 PM EDT Thursday for MEZ005-006- 011-015-016-031-032. MARINE...None. && $$ Near Term...CB/Hewitt Short Term...Duda Long Term...Cornwell/Duda Aviation...CB/Hewitt/Duda Marine...CB/Hewitt/Duda Climate...CB
Area Forecast Discussion
National Weather Service State College PA
1110 PM EDT Wed Jul 4 2018 .SYNOPSIS... Heat and humidity will continue at least until a cold front pushes southeast through the region Thursday night and early Friday. Cooler and less humid air moving in behind the cold front will last all weekend. && .NEAR TERM /UNTIL 7 AM THURSDAY MORNING/... Almost all precip is gone from the CWA, and skies are even mainly clear in the NErn third. IR shows cloud tops cooling in wrn PA, but some ltg still going near Warren Co and weak showers also trying to push in from the west as outflow boundary impinges upon the wrn mtns. Will adjust PoPs for the recent trends, with a lingering sprinkle possible over much of the area overnight. PWATs remain very high, so it might not take much lift to make a cell grow. For the most part, though, it is pretty stable. Prev... Quite the active afternoon is finally showing signs of calming down. Earlier showers and thunderstorms organized around a weak low level boundary under a mid level low. The storms were fueled by a moisture rich environment with PWATs in excess of 2 inches common over almost the entire CWA. The rain is most organized from Schuylkill and southern Columbia counties down into the vicinity of Thomasville. The activity now seems mainly focused around the plethora of outflow boundaries that have been laid out around the region from the earlier widespread storms. SPC meso page indicates overall instability is on the wane as more and more of the area gets worked over by the rain and comes under the upper cloud umbrella. The HRRR just keeps the storms going through midnight which seems unreliable in such a weakly forced environment. I trimmed the POPs down expecting activity to continue to follow the usual diurnal decline in the absences of some sort of strong forcing mechanism. Temps tonight will be quite uncomfortable once again, with mins only dipping into the upper 60s to lower 70s. && .SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY/... The sfc wind becomes more SWrly in the west for the day on Thursday and should help to focus some increase in moisture there. The lake breeze in the far NW and terrain influences elsewhere along the Alleghenies should provide focus for convection, along with random/differential heating and meandering weak outflow boundaries from the recent convection. Upper heights slowly lower a few decameters thru the day and Thursday night as a weak pre- frontal trough moves in from the NW. So, it should be easier to get more convection going. The Day2 SVR Outlook from SPC does indicate that slightly stronger winds aloft on Thurs PM (mainly across northern PA and into New York State) could support isolated wind damage. Thursday night looks very disorganized, but could be the time to include the highest PoPs, at least for the NW half of the CWA. The front approaches the NW zones around 12Z Fri, and moves through with some alacrity on Friday morning. All guidance pushes the front thru all but the far SE by the middle of the afternoon. Therefore, it would be tough to see strong convection without the benefit of daytime/peak heating for all but the SE on Friday. But, the PoPs should be OK at categorical for the morning and early aftn for the central and srn zones. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... *Cooler and refreshingly less humid air will arrive this weekend and may last into Monday. The cold front should be well to our south at 00Z Sat. Drier and There is some question as to how much upper ridging can rebound into early next week. Relief from the relentlessly hot/humid weather will arrive this weekend as cooler and less humid air sweeps southeast from Canada. Showers may drop in from the Great Lakes by the mid-week period, but Sat-Mon looks dry with seasonable temps, and welcome surface dewpoints in the 40s and 50s. PWAT values plummet to an impressive minus 2-3 sigma Saturday morning, then stay in the minus 1-2 sigma range into early Monday as an area of high pressure (1024-1028 mb on the GEFS) drifts SE from the upper midwest and becomes located over the state Sunday morning. In contrast to the fans and AC units we had constantly running throughout the week, this weekend and early next week will give us the opportunity to get out the blankets (if you choose to sleep with the windows open) Friday night through Sunday night, as temps slide well into the 40s for mins across the northern mtns, and upper 40s and 50s elsewhere. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... Area of rain and thunderstorms that plagued the north and central airfields this afternoon has sunk into the southeast. KMDT and KLNS will see -SHRA and VCTS for the next few hours before everything diminishes. Since all areas saw heavy rainfall today, added BR in the overnight period. Similar set up tomorrow as today so used persistence from last night and early today for the extended portion of the forecast. .Outlook... Fri...Shower or thunderstorm impacts possible, mainly in the morning. Sat-Mon...No sig wx expected. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo/La Corte NEAR TERM...Dangelo/La Corte SHORT TERM...Dangelo/Lambert LONG TERM...Lambert/Tyburski AVIATION...Tyburski
Area Forecast Discussion
National Weather Service Dodge City KS
505 PM CDT Wed Jul 4 2018 ...Updated Aviation... .SHORT TERM...(This evening through Thursday) Issued at 155 PM CDT Wed Jul 4 2018 Vis satellite shows some weak cumulus buildups across SE Colorado. Have only slight pops near the Colorado border to account if an isolated storm should develop in this region during the late afternoon and slowly drift to the state border. Confidence on this is not particularly high as mid level winds are very weak. Additionally, some of the meso models like the ARW and NMMB were showing early morning convection as the main trof swings thru just to our north. Did have some slight pops in there but decided to get rid of these as confidence is just not high enough. Recent versions of the HRRR show dry conditions prevailing through the overnight. Even if those models were partially correct, coverage would be extremely isolated and most areas will remain completely dry through the short term period. Otherwise, lows tonight should be in the upper 60s to lower 70s. For tomorrow, we will see slightly cooler highs with values in the upper 80s to around 90F. Some of the models do mix out more and thus have higher temps, however, there might be lingering mid level clouds that could reduce mixing slightly. Otherwise, storms tomorrow evening will be isolated once again with much of the activity remaining across Colorado. It is too early at this time to get rid of pops completely, particularly across the west and north zones where these areas are in closer proximity to whatever does develop. .LONG TERM...(Thursday night through Wednesday) Issued at 155 PM CDT Wed Jul 4 2018 Isolated thunderstorms are still possible, however, with low certainty for Friday and into the weekend. Again, not expecting widespread storms. Near normal temperatures will continue. The ridge starts to build over the Plains next business week with highs increasing. Values should trend to slightly above normal by the end of the extended period. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 505 PM CDT Wed Jul 4 2018 VFR will continue to prevail through this TAF cycle. Isolated convection near the CO/KS border is expected to have no impacts on the airports this evening. Gusty SE winds will diminish after 00z Thu, with light SE winds prevailing overnight. Thunderstorms are expected tonight in Nebraska, and some models such as the latest HRRR and the 12z ECMWF suggests some of this activity will build southward and approach HYS late tonight (09-12z Thu). Have very little confidence in these solutions, but included a VCTS/CB mention at HYS around 09z. Also kept TSRA out of the TAFs through Thursday afternoon, although some isolated activity will likely exist at peak heating. Otherwise, a cumulus field and light SE winds are expected Thursday afternoon. && .PRELIMINARY POINT TEMPS/POPS... DDC 70 91 69 90 / 10 20 10 20 GCK 69 91 68 89 / 10 20 20 20 EHA 66 90 67 90 / 10 20 20 10 LBL 68 92 68 90 / 10 10 10 10 HYS 70 91 69 89 / 20 20 30 40 P28 74 93 71 92 / 0 10 10 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Sugden LONG TERM...Sugden AVIATION...Turner
Area Forecast Discussion
National Weather Service Sioux Falls SD
1057 PM CDT Wed Jul 4 2018 .SHORT TERM...(This evening through Thursday) Issued at 259 PM CDT Wed Jul 4 2018 The 4th of July has certainly been an interesting day weatherwise. Early morning MCV tracking across the CWA forced severe convection over the eastern portions of the forecast area, with continued weak synoptic lift trailing across the Missouri River valley for much of the day. The end result has been a general stabilization of the atmosphere north of this convection, along with cooler temperatures than expected. Generally, model guidance has proven fairly useless today with poor initializations across the board, with only the RAP and the afternoon runs of the HRRR providing some value. This afternoon and tonight: The greatest severe weather risks are going to be focused along or south of the Missouri River this afternoon, as a shortwave tracks northward into the area. Latest mesoanalysis suggests MLCAPE values approaching 2000 J/KG south of the CWA, but overall marginal shear. Now that the MCV has moved far enough to the east, we should begin to see 850 mb flow focus itself across north central Nebraska, where new convection should form quickly along a convergence axis between Oneill and Ainsworth. If short term guidance is correct, this should relieve some of the pressure on ongoing convection in Charles Mix and Bon Homme counties. A small scale MCS cluster may develop and move across northern Nebraska into the evening. Further north, not as impressed with rain or convection risks through the evening festivities. It`s certainly possible the developed stratiform region of convection further south could clip the I-90 areas, but those chances are lower now. The only other area to watch will be with a frontal boundary dropping southward this evening. Convergence is minimal, but could see an isolated shower or storm form on this boundary as it moves south this evening. While most models are NOT indicating this potential, I do see some concern for redevelopment of convection after midnight south of I- 90 as the 850 mb boundary remains planted in the area. There could be just enough convergence and enhancement of the LLJ to produce a linger band of moderate rains between Sioux Falls and Sioux City. Will bump up the QPF amounts in this area, but must stress this is low confidence on occurring. Thursday-Thursday night: High pressure will bring cooler temperatures and drier air southward on Thursday. The 850 MB boundary will fail to clear the CWA however, and this certainly could bring the potential for a few daybreak showers and storms into Friday morning. Later shifts may need to add this potential into the forecast. .LONG TERM...(Thursday night through Wednesday) Issued at 259 PM CDT Wed Jul 4 2018 Friday-Sunday: Mid-level height rises will bring an increase in temperatures and humidity back into the region for this weekend. A growing 597DM ridge overhead should suppress convection this weekend. A lone precipitation chance could present itself late Sunday evening over northern South Dakota and western Minnesota along a poorly defined front. Next week: Medium range guidance seems to suggest that we`ll continue to grow a mid-level ridge over the region, again keeping precipitation chances on the lower end. Temperatures will trend above average, with rather oppressive humidity settling into the region. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1046 PM CDT Wed Jul 4 2018 Showers may linger through the lower MO River Valley into portions of northwestern IA during the overnight hours. By mid morning on Thursday any activity will end across the area with VFR conditions through the period. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ SHORT TERM...Dux LONG TERM...Dux AVIATION...JM
Area Forecast Discussion
National Weather Service Grand Junction CO
943 PM MDT Wed Jul 4 2018 .UPDATE... Issued at 943 PM MDT Wed Jul 4 2018 After looking at the 00Z run of the latest HRRR smoke forecast, have decided to go ahead and include the Highway 82 corridor from Basalt northwest to just south of Glenwood Springs and the Highway 133 corridor south through Carbondale to the Dense Smoke Advisory tonight. The Lake Christine Fire grew to over 2300 acres today and, once the nocturnal inversion sets up tonight, smoke should settle into those lower elevations. && .SHORT TERM...(Tonight through Thursday night) Issued at 220 PM MDT Wed Jul 4 2018 Heights will rise through this period as a large upper level high pressure center shifts from the Ohio Valley to the UT/CO region. Southerly steering flow on the western periphery of the anti- cyclone will persist through Thursday, then becoming light and variable under the center of high pressure Thursday night. Convection is having a tough time gaining any appreciable depth today so far. Expect any isolated showers/storms to dissipate quickly with sunset. Smoke from the 416, Burro and now the Lake Christine wildfires will affect areas downwind this afternoon, then after the inversion sets up late this evening, will begin to flow downvalley. Have issued a Dense Smoke Advisory again for the Animas River Valley/550 corridor downvalley from the 416 fire where persistent dense smoke has been a problem each night. Will have to keep an eye on the Hwy 82 corridor northwest of Basalt for dense smoke issues if the Lake Christine fire continues to grow. A subtle vorticity maximum and some increase in precipitable water Thursday should yield a little better chance of showers/storms in the afternoon, but focused over the higher terrain of Colorado from the Divide to the San Juan Mtns. .LONG TERM...(Friday through Wednesday) Issued at 220 PM MDT Wed Jul 4 2018 Strong upper level high pressure will remain centered over UT/CO through Sunday, then models agree on it migrating back to the Midwest/Mississippi Valley early next week as an upper level trough moves across the Pac NW and northern Rockies. The big forecast challenge during this period is figuring out precipitation chances and coverage. Models are suggesting quite an increase in precipitable water and instability by Friday. However, the core of the higher moisture associated with an easterly wave over the Texas coast today will be suppressed well to our south as the high pressure aloft sits directly overhead. While it is possible to see available moisture increase under the high pressure aloft, it seems reasonable to expect at least a delay of onset. Models are responding to the higher moisture and CAPE and increasing coverage of showers/thunderstorms. We are a little suspect so are not getting too excited yet. However, we will issue a Special Weather Statement for south of I-70 to address the possibility of increased thunderstorms. With weak steering flow, any storms that do develop will be slow-moving and have the potential to cause flash flooding, especially if over recent burn scars. When the high pressure center migrates east next week, flow between that and the approaching trough will set up a more reasonable expectation for higher moisture moving over the region and attendant increase in shower/thunderstorm activity. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 943 PM MDT Wed Jul 4 2018 VFR conditions will prevail at all TAF sites over the next 24 hours. Increased moisture on Thursday will allow for an increase in mid and high level clouds as well as better shower and thunderstorm coverage over the Colorado mountains after 18Z. Outflow winds to 35 knots will be the main impact from these storms through sunset Thursday evening. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...Dense Smoke Advisory until 10 AM MDT Thursday for COZ008-010-019- 022. UT...None. && $$ UPDATE...MMS SHORT TERM...BM LONG TERM...BM AVIATION...MMS
Area Forecast Discussion
National Weather Service Green Bay WI
1033 PM CDT Wed Jul 4 2018 Updated aviation portion for 06Z TAF issuance .SHORT TERM...Tonight and Thursday Issued at 334 PM CDT Wed Jul 4 2018 Scattered thunderstorms have Popped up as expected across much of the forecast area in a very unstable airmass. Two primary areas of focus are storms that have developed along the lake breeze over southern Door County. These storms have been very slow moving given the very weak vertical wind shear and are being modulated by thunderstorm outflow and aforementioned lake breeze. Recent radar trends indicate storms continue to develop along thunderstorm outflow and are training across the same area over southwest Door County. Rainfall rates of 1 to 2 inches per hour are likely and have already received a report of 3 inches southwest of SUE. Have issued a flood advisory to address this situation. West of the Fox Valley additional storms have formed along a line from western Shawano across Menominee into northern Oconto counties. Again these storms are training along the same general area but so far rainfall amounts have been less than an inch locally. Overall storm coverage will likely increase slightly for the remainder of the afternoon but they will be generally disorganized and pulse-like in nature. Storms that are slow moving or training will definitely be capable of producing a couple inches of rain in localized areas. Given the amount of instability, a few updrafts could be strong enough to generate hail up to a half inch in diameter and perhaps a wind gust to 45 mph. Overall storms should remain just below severe limits but will be monitoring closely. Finally, remnant MCS moving across northcentral Wisconsin is continuing to weaken. Last few runs of the HRRR support that trend. However its rain-cooled outflow will likely interact with storms west of the Fox Valley and lead to an uptick in the convective coverage and intensity there. Over southwest Wisconsin another MCS has been strengthening as it interacts with outflow boundary downstream. These storms have been the strongest are have the best potential for producing severe weather. Latest HRRR also suggests these storms should generally stay south of the forecast area or perhaps clip southwest Marathon and Wood counties this evening. SPC has retained slight risk into that area overnight which seems reasonable. Weak cold front will slowly sag southeast across the forecast area overnight and will keep chances for showers and storms in the forecast until Thursday morning. Overall coverage of convection should begin to wane after sunset. RAP and HRRR suggest could be a few storms along the boundary over the southern Fox Vally until about 18 UTC Thursday. Thus maintained chance pops in that region. By Thursday afternoon somewhat cooler and drier airmass should slowly infiltrate the area as winds turn northwest begins the front. .LONG TERM...Thursday Night Through Wednesday Issued at 334 PM CDT Wed Jul 4 2018 Medium to long-range models continue to be in very good agreement on the placement of a strong upper-level high pressure system across the central Rockies through the weekend, stretching into the Ohio Valley late in the weekend and early next week. Surface high pressure will spread over the Great Lakes late in the week then shift to the east early next week. These systems will bring quiet weather to the region, along with cooler and much less humid conditions through Sunday afternoon. The chance for more active weather looks to arrive late Sunday into early next week as the upper ridge flattens, heights fall as a shortwave crosses the northern U.S., and a boundary sags into the region. Cold front will be well south of the area by Thursday night into Friday, with surface high pressure working into the western Great Lakes. It will be much cooler and less humid with slightly below normal low temps ranging from the lower 50s (a few upper 40s possible) north to the middle 50s to around 60 in the Fox Valley and lakeshore. Friday looks to be a very pleasant and comfortable summer day with plenty of sunshine with highs in the upper 70s to lower 80s for most spots, except a few degrees cooler near Lake Michigan. The quiet weather continues into Saturday as the high pressure slides into Lower Michigan. Humidity levels will increase slightly, but should still be a pretty comfortable day with highs in the lower to middle 80s (slightly cooler near the lake). As the surface high shifts east of the region Saturday night into Sunday, return flow starts to ramp up across the area. Temps and dewpoints will continue to slowly creep up, but it doesn`t look to be as tropical as it was on/around July 4th, with dewpoints only in the lower to possibly middle 60s and temps in the middle 80s away from Lake Michigan. Precip chances still look very low as models show better warm air advection, low level jet, moisture, and the surface boundary remaining to our northwest. Shower/storm chances increase as we head into Sunday night and Monday as the boundary sags south into the area and moisture increases. Still a little to early to determine how intense/widespread the shower/storm activity will be, with slight timing differences impacting if storms can take advantage of peak heating. Convergence doesn`t look overly impressive with no clear low level jet pointed in our direction. Setup warrants slight/chance POPs for now. Precipitable waters over 1.5 inches by Monday afternoon, so where storms do form, heavy rain will be possible. Dewpoints climb into the 60s to near 70 on Monday, providing for a pretty sticky day. Models not in any agreement on how things play out with the boundary and what arrives mid-week but it looks to remain very summer-like. && .AVIATION...for 06Z TAF Issuance Issued at 1033 PM CDT Wed Jul 4 2018 Showers and thunderstorms have come to an end across the area overnight. Recent model runs keep the area dry through the overnight with some breaks in the clouds. These breaks could cause some fog with MVFR or IFR conditions given the recent rainfall. Any fog that forms will dissipate quickly Thursday morning. A secondary cold front may bring some showers to the area on Thursday, mainly across the southern TAF sites. However coverage and confidence is too low to include in this set of TAFs. Conditions behind this front will clear out from north to south as high pressure builds in from the west. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....ESB LONG TERM......Bersch AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service Jacksonville FL
952 PM EDT Wed Jul 4 2018 .UPDATE... The upper level low is now centered in the Ocala area with the convection over land waning due to the loss of diurnal heating. The flow around the system will keep a few light showers moving in from off the ocean but they shouldn`t progress more that 10 or 20 miles inland. They are small and moving quick so durations will be quite limited. && .AVIATION... With respect to the update above will keep VCSH at all fields, except KGNV, overnight as the showers move in from off the ocean. Should be no serious visibility or ceiling restriction and durations will be quite brief. The HRRR continues to indicate an increase in shower activity after 08:00 utc so have added a few Tempo groups for that time period, if only because the showers could be more numerous. && .MARINE...High pressure well northeast of the waters will maintain an onshore flow through Saturday. A western Atlantic begins to build south of the waters over the weekend providing a light offshore flow with afternoon seabreezes near the coast. A weak back door front will wash out across the waters early next week. Scattered showers and storms. Rip Currents: Moderate risk through Thursday due to an onshore flow and surf/seas nearshore of 2-3 ft. && .PRELIMINARY POINT TEMPS/POPS... AMG 72 90 71 91 / 30 40 20 40 SSI 77 87 76 87 / 40 40 30 30 JAX 72 88 73 91 / 30 50 30 40 SGJ 75 87 73 88 / 30 50 30 50 GNV 71 90 72 90 / 40 60 30 60 OCF 71 90 73 89 / 40 70 40 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ Sandrik/Nelson/Corless
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
655 PM CDT Wed Jul 4 2018 .SHORT TERM... (Through Late Thursday Afternoon) Issued at 402 PM CDT Wed Jul 4 2018 Isolated diurnally-driven thunderstorms are possible during the heat of the afternoon. Any SHRA/TSRA which develop should dissipate early this evening. Light south to southeast winds are expected through the early evening hours before winds turn light/variable later tonight. Smoke from area fireworks displays may struggle to dissipate this evening due to these low wind speeds as well as little mechanical mixing overnight; BUFKIT profiles from the RAP and NAM both show very light winds in the lowest few thousand feet AGL. Winds will become westerly to northwesterly after daybreak on Thu. A low pressure system moving through Canada will push a cold front into the western Great Lakes tonight. This front will continue to sag southward and then become more zonally oriented on Thu as it continues to drift southward into MO/IL. Hot and humid conditions will persist through tomorrow across most of the area, although parts of northeastern MO and west central IL could see some relief during the afternoon when clouds and thunderstorms are expected to develop near the sagging cold front and/or near a wind shift line ahead of the T/Td discontinuity associated with the true frontal boundary. The existing Heat Advisory looks reasonable considering today`s hot/humid conditions will be followed by little overnight relief and yet another day of heat/humidity on Thu. Overnight lows tonight should be in the mid/upper 70s across most of the area, and slightly warmer highs on Thu will yield heat indices of 105-107 across the advisory area on Thu. Farther west, slightly lower dew points will produce slightly lower heat index values of 100-104. Depending on the extent of cloud cover, the Heat Advisory may need to be expanded westward for areas near and south of the Missouri River. Kanofsky .LONG TERM... (Thursday Night through Next Wednesday) Issued at 402 PM CDT Wed Jul 4 2018 The cold front should be drifting through Missouri and into central and southern Illinois Thursday night. The eastern periphery of the H5 ridge will be over the lower Missouri and middle Mississippi Valleys Thursday evening. Mid to upper level lapse rates are not particularly impressive with the upper ridge overhead, but low to mid level lapse rates are forecast to be between 7-8C/km for a few hours during the evening resulting in MUCAPE in excess of 2200 J/Kg. CINH values are rather high, so surface based convection seems unlikely, and this is probably why most of the models really back off their QPF during the evening. However, am concerned that the PoPs these lower QPF values yield may not be representative of the actual precipitation chances. Have therefore bumped the chance of precip up a bit for most locations on Thursday night. The front is expected to slow a bit on Friday morning and hang over southern Missouri/Illinois. This should provide a focus for additional scattered convection through Friday afternoon. The mid Mississippi Valley is in store for some spectacular mid- summer weather this weekend. Medium range guidance continues to show a sprawling Canadian high moving into the upper Midwest and Great Lakes region. Below normal highs in the mid 80s are expected for most of the area each day. Saturday and Sunday morning lows will be in the lower 60s and even upper 50s. The upper level ridge will build back over the region early next week. Temperatures will drift back up into the 90s across most of the region and humidity levels will increase again as southerly flow is reestablished over the mid Mississippi Valley. Have some low PoPs in the forecast as the higher RH moves back into the area, but at this point timing and coverage is low confidence. Carney && .AVIATION... (For the 00z TAFs through 00z Thursday Evening) Issued at 633 PM CDT Wed Jul 4 2018 Mainly dry and VFR conditions are expected at the terminals during the period. Only exceptions will be this evening when there will be the possibility for lingering smoke from fireworks. There will also be an increasing chance for thunderstorms over northern Missouri and central Illinois into KUIN as a cold front moves south into the area. Any storm could bring MVFR/possible IFR conditions and brief downpours. Southerly winds will become light and variable as the front approaches the area and then shift northwesterly behind the front. SPECIFICS FOR KSTL: Mainly dry and VFR conditions are expected through the period. Only exception will be this evening when there will be the possibility for lingering smoke from fireworks. Southerly winds will turn light and variable this evening but then turn northwesterly behind a cold front tomorrow. Britt && .LSX WATCHES/WARNINGS/ADVISORIES... MO...Heat Advisory until 8 PM CDT this evening for Audrain MO-Boone MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO- Knox MO-Lewis MO-Lincoln MO-Marion MO-Moniteau MO-Monroe MO- Montgomery MO-Osage MO-Pike MO-Ralls MO-Shelby MO-Warren MO. Heat Advisory until 8 PM CDT Thursday for Iron MO-Jefferson MO- Madison MO-Reynolds MO-Saint Charles MO-Saint Francois MO- Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO- Washington MO. IL...Heat Advisory until 8 PM CDT this evening for Adams IL-Brown IL- Pike IL. Heat Advisory until 8 PM CDT Thursday for Bond IL-Calhoun IL- Clinton IL-Fayette IL-Greene IL-Jersey IL-Macoupin IL- Madison IL-Marion IL-Monroe IL-Montgomery IL-Randolph IL- Saint Clair IL-Washington IL. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Lubbock TX
639 PM CDT Wed Jul 4 2018 .AVIATION... Deep easterly flow becoming firmly established with upper ridge center relocating over the central Rockies and high plains by late Thursday. An upper impulse in the easterly flow, moving to the west over the southern Texas Coastal Plains, will steer far to our south early Thursday. Expect, however, in increase in low level moisture early Thursday - enough for low clouds - but how low is uncertain. Latest HRRR continues to indicate a chance for at least brief IFR ceilings reaching KLBB during the pre-dawn hours Thursday, but not seeing this on other solutions. Have added a FEW020 at KLBB for now and keep an eye on trends, updating as necessary. Otherwise continuing to favor cloud decks just above MVFR. RMcQueen && .PREV DISCUSSION... /issued 327 PM CDT Wed Jul 4 2018/ DISCUSSION... A little bit of a welcome cooling will occur after today with increased chances of precipitation for the weekend. The mid level moisture plume that has been overhead the past several days is still not totally scoured out. It will still provide a slight chance of thunderstorms for the rest of this afternoon into the early evening with greatest chances across the extreme southern Texas Panhandle. Some of the cumulus field has become more agitated and enhanced around the edge of the caprock from Briscoe into Floyd Counties. Sufficient instability around 500-1000 J/kg under a deeply mixed and warm atmosphere will lead to high based and unorganized isolated storms as far east as the edge of the caprock. Stronger storms will exist in eastern New Mexico and may extend into the extreme southwestern Texas Panhandle. An expansive upper level ridge will shift to the north tomorrow taking with it the remaining portion of the mid level moisture plume. The center of the ridge will shift farther to the west on Friday allowing stronger low level moisture advection into West Texas. This will generally keep temperatures closer to seasonal averages this weekend. Models continues to depict weak short waves rotating around the east/southeastern side of the upper ridge which will provide better chances for thunderstorms this weekend into early next week. It still remains extremely difficult and unclear to pin down any time for better chances of precipitation. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 99/99/05
Area Forecast Discussion
National Weather Service Riverton WY
240 PM MDT Wed Jul 4 2018 .SHORT TERM...(This evening through Thursday) Issued at 240 PM MDT Wed Jul 4 2018 Visible satellite imagery shows cumulus field across the western mountains and the Great Divide Basin Wednesday afternoon. The southern Absaroka Range has the best potential for isolated convection to develop around 3pm/Wed before winding down by 9pm/Thu. Recent runs of the HRRR are trying to develop isolated convection from the cumulus field over the Great Divide Basin and bring it northeast through Natrona County. This possibility cannot be ruled out, but would expect little more than gusty outflow wind of 30-40 mph. Any jet energy of consequence has pulled away to the north and a ribbon of CIN is still in place across central Wyoming. Any weak showers or storms that develop will be diurnally driven and will dissipate by late Wednesday evening. It will be mostly clear overnight with the possible exception of Natrona County. Boundary layer relative humidity along with easterly upslope flow across the county could lead to the development of a lower cloud deck early Thursday, generally between 4am and 10am. 500mb heights will rise Thursday as 600dm height center sets-up over eastern Colorado/western Kansas. Thus, it will be warmer Thursday with temperatures at least slightly above normal. Southeast return flow around high pressure in the Northern Plains will transport low-level moisture into Johnson and Natrona counties Thursday. Pseudo-dry line along the east slopes of the Bighorn Range down to Hiland will separate the higher dew points of 50-55F from rapidly decreasing dew points west of this line. The higher dew point air coupled with favorable directional shear profile should lead to thunderstorms, some possibly strong, in Johnson and Natrona counties late Thursday afternoon. SPC day 2 outlook now includes this area in a marginal risk for severe thunderstorms. The higher terrain, especially the Bighorn Range, would be the likely area for initial convective development around 3-4pm/Thu. There will also be enough mid-level moisture in southerly flow aloft to initiate weak convection over the central and northern mountains again Thursday afternoon, similar to Wednesday. .LONG TERM...(Thursday night through Wednesday) Issued at 240 PM MDT Wed Jul 4 2018 South-southwest flow bringing hot and relatively dry air north across western and central Wyoming will support mainly isolated showers and thunderstorms over the central and northern mountains Thursday evening. Then, dry and hot conditions will dominate the weather Friday with even hotter temperatures on Saturday when much of the lower elevations east of the Continental Divide could exceed 100 degrees. There is an outside chance of isolated thunderstorms across the south Saturday afternoon spreading north into the western and central mountains on Sunday. Some cooling is expected Tuesday and Wednesday with isolated mainly afternoon and evening showers and thunderstorms. && .AVIATION...(For the 00Z TAFS through 00Z Friday) Issued at 240 PM MDT Wed Jul 4 2018 VFR conditions expected through 00Z/Friday at all terminals with one short duration exception. Boundary layer moisture will increase from the east at KCPR early Thursday in association with return flow around high pressure in the Northern Plains. This moisture push and weak upslope flow may very well generate lower ceilings and localized IFR or MVFR around KCPR between 10Z-16Z/Thu. This would lead to mountain top obscurations above about 7,000 ft MSL across Natrona County. Isolated weak convection this evening will be diurnally driven and end around 03Z/Thu. Mid-level moisture in southerly flow aloft will provide a similar convective set-up Thursday with isolated late day showers and storms moving east off the northern and central mountains. && .FIRE WEATHER... Issued AT 240 PM MDT Wed Jul 4 2018 A cold front slipped south through central Wyoming early Wednesday. This will keep fire weather concerns below critical through the remainder of Wednesday afternoon. Warmer and drier air will remain in place into the evening hours across zones 277, 278, and 279, but wind speeds will generally be 15 mph or less. Isolated showers and storms over the central and northern mountains will likely dissipate as they move east off the mountains. The primary hazard will be gusty outflow wind of 30 to 40 mph. It will be warmer across the entire forecast area Thursday as high pressure takes control over the central Rockies. For the most part, relative humidity will remain above 15 percent with zones 280 and 281 the most likely locations for wind speeds of 15 to 20 mph. This wind will be from the southeast and will transport low-level moisture into these zones. Late day isolated showers and storms will again form over the central and northern mountains Thursday. The moist, low-level southeast flow will also produce isolated showers and storms over zones 280 and 281. Conditions will continue to trend hotter and drier Friday and Saturday. Not only may Saturday be the warmest day of the season, but increasing westerly wind is likely to lead to elevated fire weather conditions. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CNJ LONG TERM...Baker AVIATION...CNJ FIRE WEATHER...CNJ
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
453 PM MDT Wed Jul 4 2018 .DISCUSSION...(This Evening Through Wednesday) Issued at 148 PM MDT Wed Jul 4 2018 The latest water vapor images and RAP 500-mb analysis show a broad ridge extending from the East Coast back to CO/NM. One short-wave trough/upper low was spinning over Saskatchewan/ Manitoba, with a larger upper low off the Pacific Northwest Coast. A trailing cold front from the southern Canada low has pushed through all the CWA, but moist and unstable air was lingering over south-central SD where showers/storms were occurring. The rest of the CWA was relatively dry with northwest surface flow bringing dew points in the lower 40s to upper 50s. Other than south-central SD, the rest of the CWA was mostly sunny, except for some stratocumulus over the central/western Black Hills. The showers/ storms over south-central SD should move eastward by 03z as the cold front continues to move southeast. On the large scale, the upper high/ridge will build westward to near the four-corners area by late Friday, fostering a very warm pattern through the weekend. Saturday should be the hottest day with highs well into the 90s. Rainfall chances will be minimal, but a few thunderstorms will be possible at times as subtle/weak short-wave troughs rotate around the ridge. This will be aided by evapotran- spiration given the anomalous greenness and surface moisture from the rainfall over the past several weeks, allowing for humidity and CAPE to build up. The ridge is forecast to flatten some next week, which may be associated with a slightly better chance for thunderstorms. && .AVIATION...(For the 00Z TAFS Through 00Z Thursday Evening) Issued At 453 PM MDT Wed Jul 4 2018 VFR conditions are expected through the period. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION...Bunkers AVIATION...JC