Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/04/18

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
804 PM CDT Tue Jul 3 2018 .UPDATE... Issued at 801 PM CDT Tue Jul 3 2018 Allowed heat advisory to expire. Developing thunderstorms are adding to the cloud cover and temperatures are dropping in areas receiving rain. Drier spots across south central SD will slowly cool after sunset. UPDATE Issued at 630 PM CDT Tue Jul 3 2018 Made a few tweaks to evening pops based on latest HRRR and current radar returns. Otherwise, forecast remains on track for the overnight period with two rounds of storms possible. && .SHORT TERM...(This Evening through Wednesday) Issued at 223 PM CDT Tue Jul 3 2018 Convection remains the main challenge in the short range. Instability continues to increase across the region this afternoon as diabatic heating continues. However, deep layer shear is probably slackening as the mid level westerlies retreat to the north this afternoon and evening. Also, heights continue to build across the region with warming temps aloft. Meanwhile, ll shear will remain decent through tonight given continued llj, and its diurnal increase this evening. The CAMS and non-CAMS are at odds concerning convective development in the northeast toward evening. The HRRR is somewhat aggressive, perhaps picking up on outflow boundaries left behind by the morning convection. Non-CAMS favor activity developing further north, or not at all over the northeast this evening. Later in the evening there is fair agreement that an MCS will fire up over the High Plains, and then head northeast overnight. The main threat with the possible early evening convection will be hail and heavy rain, and the late night activity should favor gusty winds. Nonetheless, confidence in how all this will play out is fairly low attm. Temperatures will be above normal through Wednesday. .LONG TERM...(Wednesday Night through Tuesday) Issued at 223 PM CDT Tue Jul 3 2018 Mid level ridge will expand from the eastern conus, back west to the central conus during the period. The ridge does get knocked down some by passing s/w energy late in the weekend, into early next week. That is likely the best opportunity for any meaningful pcpn during the period, since prior to that the strong mid level ridge should provide for general subsidence across the Northern Plains. Meanwhile, temperatures should remain near to above normal through most of the period. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 630 PM CDT Tue Jul 3 2018 VFR conditions are expected to prevail except in the vicinity of thunderstorms. Strong winds and large hail will be possible with any storms this evening and overnight. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Wise SHORT TERM...TDK LONG TERM...TDK AVIATION...Wise
Area Forecast Discussion
National Weather Service Gaylord MI
1156 PM EDT Tue Jul 3 2018 .UPDATE... Issued at 1016 PM EDT Tue Jul 3 2018 Surface high pressure is over the eastern Great Lakes this evening with southerly return flow becoming established across Michigan. Low-mid level theta-e axis across the lower lake region is making northward progress evidenced by some cloud cover working north and pop-up showers in far southern lower MI. Lower level moist layer and corresponding gradient of modest instability will continue to push up into the region overnight. No big synoptic forcing mechanisms in play, but guidance does have a slight uptick in the low level flow/jet which could eventually force some isolated showers late as suggested by some high-res guidance solutions and as spelled out in our going forecast in our southern counties. Not real confident that will happen, but I can`t say it will not either. So I`ll probably just leave the slight chance pops alone for now. && .NEAR TERM...(Through Tonight) Issued at 309 PM EDT Tue Jul 3 2018 ...A few showers creeping north overnight... High impact weather potential...none. High pressure over the eastern lakes extends ridging back into northern lower MI. This is supporting abundant sunshine, with mid afternoon temps in the lower 80s to lower 90s. High pressure heads a bit further east tonight, while a weak wave of low pressure forms on a warm front just north of Superior. That tightens up the pressure gradient a bit, allowing better moisture to gradually advect northward. Spotty convection is already seen to our south, just south of MI. Primary forecast concern is whether any of that can linger into the overnight as it heads north. Nam Bufr soundings show a moist layer (900-800mb) pushing north into southern portions of the forecast area late in the overnight. There is still a cap at 700mb (+10C), but if the Nam is correct there is enough moisture to largely erode that cap. The Nam is likely overdone with moisture return (a typical bias). But it`s not alone; most HRRR runs have isolated showers making it to northern lower MI overnight, while the RAP actually brings substantial rains to s central sections overnight. That looks way overdone...but there`s enough moisture/instability to add a slight chance of showers after 4 am for CAD/HTL/Gladwin/Grayling. Mostly clear skies in the 1st half of the night, becoming partly cloudy in the south overnight. Min temps a few degrees warmer than last night, primarily in the 60s. && .SHORT TERM...(Wednesday through Friday) Issued at 309 PM EDT Tue Jul 3 2018 ...Warm and humid through Thursday, then drier... High Impact Weather Potential: Minor, mainly dry through Wednesday afternoon before increasing chances for thunderstorm potential Wednesday night and Thursday. Primary Forecast Concerns/Challenges: The primary forecast challenge will be thunderstorm potential and the associated threats. Pattern Synopsis/Forecast...A large area of high pressure centered over the mid Atlantic and Ohio Valley since Monday night, will slowly breakdown over the Great Lakes Wednesday evening. A weak surface boundary, associated with a storm system moving across Ontario, will sweep over the nrn lakes Thursday as the system exits into Quebec. Overall will continue with a mainly dry forecast over much of northern Michigan through Wednesday afternoon, as dynamics associated with approaching boundary will be confined to an area right along the front. 850/700mb qvector convergence shows strong forcing dropping into upper Michigan along the boundary around 06z Thursday, and into nrn lower between 12z and 18z Thursday. Model soundings and mstr progs show sufficient low and mid lvl moisture (sfc dew pts nearing 65 with 850mb dew pts around 18c) and instability (0-3km MUcape around 2500j/kg) to generate a line of thunderstorms in advance of the boundary. Kindex around the mid 30s, pwat over 1.75 inch and Dcape over 1000j/kg would suggest strong wind gusts and heavy rainfall with any thunderstorms. The airmass quickly dries and becomes more stable on the backside of the boundary (sfc dew pts fall into the upper 50s to around 60) while high pressure and subsidence quickly filtering back into the Great lakes by late Thursday afternoon and evening. It will be much cooler and drier Friday as high pressure settles back over the region and sfc dew pts fall back into the upper 40s and lower 50s. .LONG TERM...(Friday night through Tuesday) Issued at 309 PM EDT Tue Jul 3 2018 A warm and largely dry pattern to setup across the northern Great Lakes through the forecast period. Broad upper trough over the eastern Great Lakes to begin the weekend will slowly push east as 500mb heights begin to build over the upper midwest and Great Lakes to begin the upcoming work week. Mild mid lvl temperatures in this pattern will generate afternoon highs around 80 saturday warming into the mid 80s for the remainder of the forecast period. The large area of high pressure centered over the state through hte weekend will maintain dry conditions over nrn michgian through Monday while the chance of pcpn increases Tuesday as a storm system moving over Ontario drops south into the Great lakes. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1155 PM EDT Tue Jul 3 2018 Surface high pressure is over the eastern lakes region with southerly return flow becoming established across Michigan. Still quiet out there with solid VFR flight conditions. But there is a lower level moisture axis making northward progress from the lower lakes up into northern Michigan evidenced by some (VFR) cloud cover trying to work into the region and a few showers/storms in far southern lower Michigan. Return moisture and some cloud cover will work up into northern Michigan tonight although I`m not expecting much by way of precip at the terminal sites. Wednesday remains VFR, but there will SCT to BKN daytime CU development and pop-up shower chances will also be on the increase. && .MARINE... Issued at 309 PM EDT Tue Jul 3 2018 Winds and waves are expected to remain below small craft criteria through the forecast period. A large area of high pressure will generate mainly dry conditions across nrn Michigan nearshore waters through Wednesday afternoon. Thunderstorms chances increase Wednesday night and Thursday as a weak frontal boundary drops south over nrn Michigan. Variable winds under 10kts through Wednesday will trend southwest Thursday morning, before becoming gusty northwest Thursday evening on the backside of the exiting sfc boundary. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...BA NEAR TERM...JZ SHORT TERM...SR LONG TERM...SR AVIATION...BA MARINE...SR
Area Forecast Discussion
National Weather Service Bismarck ND
1018 PM CDT Tue Jul 3 2018 .UPDATE... Issued at 1003 PM CDT Tue Jul 3 2018 Severe thunderstorm watch #261 has been issued for almost all of western and central North Dakota. There are two main areas of concern with the activity currently moving into western North Dakota. One will be the complex of storms over eastern Montana as it approaches the Williston area and northwest North Dakota. The other will be the activity that has already started moving into the southwest from northwest South Dakota, which has already prompted a severe thunderstorm warning over Bowman county. Coverage and intensity should increase as the low level jet kicks in over the next 1 to 3 hours. Should storms hold together, they are likely to approach the Bismarck/Mandan area in the 06z to 08z time frame, possibly transitioning into a severe QLCS as it approaches the James River Valley. Populated precipitation chances with the latest iteration of the time lagged HRRR which seems to have a decent handle on the ongoing convection. UPDATE Issued at 641 PM CDT Tue Jul 3 2018 No major changes were needed for this update. Just tweaked precipitation chances through 12z using a blend of the latest time lagged HRRR and the latest run of CONSSHORT guidance. Still think a strong to severe storm may be possible in the next couple of hours over the far southern James River Valley. The next round, that will enter the southwest around 02z to 05z, will likely track across the southern third of the forecast area through the overnight hours. Some of these storms may also become strong to severe. && .SHORT TERM...(This evening through Wednesday) Issued at 206 PM CDT Tue Jul 3 2018 The main forecast issue in the short term period will be thunderstorm chances tonight. Currently, low pressure was situated over central South Dakota with a warm front into eastern North Dakota, and a weak inverted trough into north central-northwest ND. The area of low pressure and warm front will remain nearly stationary through this evening. Low pressure will continue to develop over eastern Montana and the western Dakotas ahead of an upper low and associated shortwave trough currently tracking through the northern Rockies. We continue to destabilize this afternoon over the Dakotas with current MLCAPE values around 500-1000J/kg north to nearly 3000J/kg over portions of the southern James River Valley, and a broad area of 50-60 knots of deep layer shear over most of the state of ND. CAMS have been pretty consistent in developing two areas of convection this afternoon/early evening. The first is along the Canadian border over northwest/north central ND in an area of steepening low level lapse rates. Even though deep layer shear is significant here, mid level lapse rates lag behind the central and southern portion of the state and CAPE values are more meager. The southern James River Valley and into northeast South Dakota is the second area of convection to focus on early in the forecast period. Very unstable airmass exists here with steep mid level lapse rates and abundant low level moisture. The threat for very large hail will exist here as well as possible tornadoes, especially as you get farther south, along the far southern tier counties and moreso into South Dakota. This will be the favored area to monitor late this afternoon into this evening. Later tonight the aforementioned shortwave trough should have fired convection over the northern high plains and it will be making its way into the Dakotas. Some of the CAMS suggest another possible bowing segment somewhere in the vicinity of the ND/SD border. There may be another area that clips the northwest portion of the state, associated with the upper low. The threat of severe weather in this area is more uncertain, with a marginal risk from SPC up to the Canadian border. The upper trough finally pushes convection completely through the forecast area by the morning of the 4th. This will bring clearing skies from west to east in the morning and mostly sunny but breezy to windy conditions in the afternoon. Highs will range from the mid 70s to mid 80s. .LONG TERM...(Wednesday night through Tuesday) Issued at 206 PM CDT Tue Jul 3 2018 Wednesday night through Saturday, an upper level western ridge builds behind the exiting upper low, and this ridge expands into the Plains. This should result in a generally thunderstorm free period with a warming trend. However, an isolated storm due to the heating of the day can not be completely ruled out somewhere in the forecast area. Look for highs Thursday from 75-85F, warming to 85-95 for Friday and Saturday. On Saturday afternoon we see heat indices rise to around 100F ahead of a cold front that pushes through the forecast area, bringing a chance of thunderstorms. Will need to monitor for possible heat advisory conditions, but thinking now that we will not reach criteria for a long enough period. Another strong upper level shortwave moves east out of the Pacific Northwest Saturday/Saturday night, dampening the upper ridge and bringing chances of showers and thunderstorms to our area Saturday night, followed by a more zonal flow across our area Sunday through Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 641 PM CDT Tue Jul 3 2018 Another round of strong to severe storms is likely to enter southwest North Dakota around 02z to 05z, before increasing in coverage and making its way across the forecast area. Thunderstorms will be possible at all sites during the overnight hours, but the best chance for large hail and strong winds will generally remain over the southern third of the forecast area. For the most part, VFR conditions and light winds are expected, but winds may become erratic with temporary visibility reductions under heavier storms. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ZH SHORT TERM...TWH LONG TERM...TWH AVIATION...ZH
Area Forecast Discussion
National Weather Service Denver/Boulder CO
819 PM MDT Tue Jul 3 2018 .UPDATE... Issued at 811 PM MDT Tue Jul 3 2018 Strongest storms are over the far northeast plains where the best cape exists this evening. Elsewhere there are widely sct high based showers and isold storms over the rest of the area. Overall don`t expect a repeat of last evening where storms developed over the metro area and continued over portions of the plains past midnight. && .SHORT TERM...(This evening through Wednesday) Issued at 230 PM MDT Tue Jul 3 2018 An upper level trough will continue to progress to the east over the Great Basin. For this evening, the main threat of isolated high based showers and thunderstorms will continue with potential wind gusts to 50 mph. There is also a marginal risk of severe storms due to 1000 to 2000 J/kg of CAPE and minimal CIN which could produce hail. Any storms on the eastern plains will likely be sparked from outflow initiated by storms to the west. The HRRR Smoke Model continues to show smoke from area fires spreading onto the eastern plains through the evening which is supported by southwest winds. Wednesday smoke is expected to linger over the eastern plains. A mid-morning front will push into northeastern Colorado sparking showers and thunderstorms as it pushes against the terrain boundaries of the Front Range Foothills and Palmer Divide. Soundings show enough surface warming with cooler upper level temperatures leading to support an unstable environment. QG levels will be neutral to slightly negative aiding little to thunderstorm formation. Afternoon storms are expected to start near those orographic boundaries along the Front Range Foothills and Palmer Divide then spreading northeast over the plains. .LONG TERM...(Wednesday night through Tuesday) Issued at 230 PM MDT Tue Jul 3 2018 The upper level ridge will be most of central and eastern CONUS late Wednesday pulling in SSW flow. Moisture levels will increase with PWAT values over an inch and approaching 1.3 by 00z Thursday. The frontal boundary will have moved through earlier in the day destabilizing conditions along the southern foothills and Palmer divide. ML CAPE values around 00z range from 1500-2000 j/kg up to 3000 over the NE plains. Upper air soundings over the Denver region show good mid-level lapse rate of 10 C/km with cooling aloft and PW values over an inch into the evening hours on Wednesday. Bulk layer shear will range from 25-35 kts according to various models with the best shear east of Denver. Although not impressive, it could still support a few supercells across the metro into the evening hours on Wednesday. Main threats with the storms will be brief moderate rain due to the increased moisture levels, gusty winds, lightning and hail given better saturation in the growth zone. Further east, soundings continue to have a decent cap in place into the evening, but with ML CAPES approaching 3000 j/kg and shear in the mid 30s, if an outflow boundary were to move through the area it could give the atm what it needs to destabilize and support storms into the late evening hours. Thursday will continue to see unstable conditions as the upper ridge pulls moist SW flow over the region. High chance of storms by the afternoon Thursday with the main threats once again being moderate to heavy rain, lighting, winds and some hail chances. QPF amounts are higher for Thursday afternoon and evening with a quarter to half an inch possible with the stronger storms. By Friday and into the weekend the upper ridge pushes west turning upper level flow from a SSW direction to a more NNE direction pulling in increasingly dryer air in the mid levels. Some storms could form along the mountains by the late afternoon, but should remain dry on the plains. Highs for Friday will approach the 90s once again and get progressively warmer through the weekend. Over the next few days the upper ridge will gradually become more elongated. At the surface a building lee side low will help to keep conditions on the plains more stable with just a slight chance of storms over the higher terrain. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 811 PM MDT Tue Jul 3 2018 Boundaries are all over the place this evening, however, winds have become mainly northeast. At this point winds may transition to a more southeast direction, in the next hour or so, and then become more soiuth to southeast by 06z. Meanwhile I don`t expect a repeat of last night`s tstm activity, however, can`t rule out a high based shower during the next few hours. && .FIRE WEATHER... Issued at 811 PM MDT Tue Jul 3 2018 Red Flag warnings have been allowed to expire. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...RPK SHORT TERM...Sullivan LONG TERM...Bowen AVIATION...RPK FIRE WEATHER...RPK
Area Forecast Discussion
National Weather Service State College PA
1143 PM EDT Tue Jul 3 2018 .SYNOPSIS... The hottest and most oppressive heat has peaked, but it will remain hot and humid through Friday. Isolated to scattered thunderstorms with locally heavy downpours are possible through Friday. Cooler and less humid air will arrive this weekend. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Radar shows most of the convection hugging the periphery of the CWA with scattered storms over the Laurels and along the southern borders of York and Lancaster. Storms over the northern mountains have faded greatly from earlier levels. The HRRR is way too hot over the north where it shows a large convective cluster from Erie almost to the Poconos. Disturbingly it really blows up the SERN convection as it simultaneously expands the northern convection down into the Central Mountains by midnight. While the SPC meso pages does show an awful lot of mixed layer CAPE, it`s hard to see what will trigger such a widespread expansion of activity as we begin to diurnally cool. I still like winding down the overall activity as we move through the evening hours, but keeping the potential for scattered storms in the humid unstable airmass. The atmosphere is quite wet with PWATs approaching 2", so any of these pulse storms could bring brief torrential rains. WPC Excessive Rain Outlook has much of the area in a marginal risk. The lowest 3hr FFG is over the western Alleghenies where terrain could be a contributing factor. Locally heavy rains over urban areas would also likely cause some problems. 65-75F dewpoints and nearly calm winds should promote areas of fog or patchy low clouds into early Wednesday morning. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... The Fourth of July should start with areas of low clouds and fog before skies turn partly sunny. Model blends are showing a decent signal for scattered afternoon thunderstorms especially across the northern 2/3 of the CWA. Much like today, very high PW air indicates the potential for locally heavy downpours with a low risk of isolated flash flooding. D2 WPC ERO places some of the area in a marginal risk. Max HX values Wednesday afternoon will push heat advisory criteria over the Lower Susquehanna Valley. Given the holiday and plenty of outdoor festivities, some consideration will be given to a heat advisory, but will allow later shifts to make the final call. Did cover this in the updated HWO. Diurnal convection should again wane into the evening hours, hopefully avoiding area fireworks shows. Still can`t rule out a stray shower or thunderstorm into early Wednesday night. Another very humid and muggy night in store across central PA. && .LONG TERM /THURSDAY THROUGH TUESDAY/... *Sweltering heat/humidity will gradually lose its grip through late week *Cooler and less humid air will arrive this weekend Pattern Overview: Anomalous closed upper level ridge centered over the Northeast U.S. on Wednesday will retrograde westward toward the Rockies by next weekend, allowing an upper trough over southeast Canada to dip into New England. The upper trough is forecast to amplify and send a cold front through the region on Friday, breaking the heat wave and returning temperatures to near average for early July. There is some question as to how much upper ridging can rebound into early next week. Weather threats/highlights: Additional storms Thu aftn-eve with perhaps a better concentration in the NW with a lake breeze and the approach of a front from the Upper Great Lakes. Strong thunderstorms may accompany the cold front on Friday. Timing of the front and extent of cloud cover will be key factors in determining severe storm risk. Relief from the relentlessly hot/humid weather will arrive this weekend as cooler and less humid air sweeps southeast from Canada. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... An isolated shower or thunderstorm will remain possible overnight. However, the odds of any one spot being affected are low. The main issue overnight will be patchy late night fog. Local IFR conditions are possible between 08Z-12Z, mainly where rain has fallen this evening, such as KBFD and KIPT. Any early morning fog will mix out by late morning. Focus will then shift toward scattered afternoon and evening thunderstorms, which could produce a brief vis reduction in spots. .Outlook... Thu...Patchy AM fog possible. Isolated PM thunderstorm impacts possible, mainly northwest Pa. Fri...Shower or thunderstorm impacts possible, mainly in the morning. Sat-Sun...No sig wx expected. && .CLIMATE... Early July record highs for select sites... 7/3 7/4 Harrisburg 107(1996) 104(1966) Williamsport 100(1966) 100(1990) Altoona 97(1966) 97(1966) Bradford 91(1966) 91(1990) && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte/Steinbugl NEAR TERM...La Corte/Steinbugl SHORT TERM...Steinbugl LONG TERM...Gartner/Steinbugl AVIATION...Fitzgerald CLIMATE...
Area Forecast Discussion
National Weather Service Duluth MN
1100 PM CDT Tue Jul 3 2018 .UPDATE... Issued at 1100 PM CDT Tue Jul 3 2018 Made some adjustments to the next 24 hours in the forecast based on the early 00z guidance rolling in. Late tonight through early Wednesday morning, POPs have been drastically cut down as the possibility for any thunderstorms looks to be confined to just parts of north-central Minnesota where the leading edge of a low level jet will ramp up in the next few hours. Most convection- allowing guidance tries to create a massive cold pool from the nearly stationary thunderstorm in west-central Minnesota near Appleton, but so far this evening that has not happened. (Most CAMs seem to have a habit of going a bit overboard with cold pools and firing additional convection on the cold pool boundary.) While outflow from this storm may eventually spark additional storms in western Minnesota, in north-central any convection overnight looks to be weak and limited in areal coverage. For Wednesday, guidance seems to be coming into better agreement on the evolution of convection but there remains a great spread in temporal solutions. In general the large line of storms across the ND/SD border west of Bismarck will track eastward in a very healthy environment to sustain storms with SPC Mesoscale Analysis depicting 3000 to as much as 5000 j/kg MUCAPE ahead of these storms. As they track into western Minnesota Wednesday morning, the elevated instability over the eastern Dakotas this evening will advect northeast resulting in around 2000 to as much as 4000 j/kg MUCAPE over central and northern Minnesota by mid-morning Wednesday with deep layer wind shear on the order of 30-35 knots. Exactly when these storms might roll across NE MN is the big question - a slower arrival could allow additional instability to develop ahead of the line resulting in strong/severe storms around mid-day, but an earlier arrival could mean weaker storms and cause convective overturning to lower the chances for an afternoon/evening round of storms. In general kept a trend with increasing POPs mid day through the evening hours across in northeast Minnesota, transitioning into NW Wisconsin in the late afternoon/evening timeframe. && .SHORT TERM...(This evening through Wednesday) Issued at 352 PM CDT Tue Jul 3 2018 Forecast focus through the short term will be on additional showers and storms, the severe threat with the storms, and the heavy rain potential. As of 2045Z, only a few showers were occurring across the Northland. South/southwest 850MB winds from 30 to 45 knots are forecast from the RAP this afternoon over eastern South Dakota into northern Minnesota. Area VWP lend support to those winds, although the stronger values are not sampled by the 88D network at this time. The RAP forecasts these winds to decrease into the evening before they start to increase again later tonight through South Dakota into western Minnesota and our western CWA. The SPC mesoanalysis page was showing very high MUCAPE values from 2000-4000 J/KG just south and west of the Northland with MLCAPE values nearly as high. PWAT values were 1.5 to 1.8 inches so there is plenty of instability and moisture for additional storms tonight, some of which could be severe. Persistent moisture transport into the area will should keep chances for more showers/storms fairly widespread but they will be highest over our western CWA which is closer to the LLJ. Much of the higher resolution CAMS suggest coverage should start to increase after 00Z and especially late evening and overnight. We will add northern Aitkin County to the Flood Watch and leave the times as is. Showers/storms will likely be ongoing over parts of the Northland Wednesday morning, again chances will be highest over northern Minnesota. A very unstable airmass should develop ahead of a frontal boundary Wednesday afternoon, although it will be somewhat dependent on storm/cloud debris from overnight convection, and adequate deep layer shear should be in place for severe storms over much of the Northland, but especially eastern Minnesota into northwest Wisconsin in the afternoon and evening. Western portions of the Northland should see minimal storm coverage by evening but eastern Minnesota and especially northwest Wisconsin should see some storms into the evening. Wednesday will be a warm and muggy day, especially after the morning convection/cloud debris diminishes. .LONG TERM...(Wednesday night through Tuesday) Issued at 352 PM CDT Tue Jul 3 2018 Showers and thunderstorms, some strong to severe, continue into Wednesday night before high pressure builds in for the remainder of the week through Saturday. Rain and thunderstorm chances return Saturday night through Monday morning. A cold front will progress southeastward through the Northland Wednesday night. Pre-frontal thunderstorms will likely be ongoing at 00Z and will advance generally eastward during the evening hours. Strong to severe storms are possible, along with a risk of heavy rain, which may lead to flash flooding. High pressure is forecast to build into the region from the northwest on Thursday ushering in a period of quieter and drier weather. The ridge gradually slides southeastward into the Ohio Valley by Saturday night as a shortwave trough approaches from the west. Southwesterly flow in the wake of the departing high will bring moist and unstable air back into the Northland ahead of a surface cool front. Showers and thunderstorms will be possible from the eastern Dakotas into northern Minnesota Saturday night, and over the remainder of eastern and northeast Minnesota and northwest Wisconsin on Sunday. The cool front will taken on a west-east orientation over central portions of Wisconsin and Minnesota by Sunday afternoon, and will push northward as a warm front Sunday night. A strengthening low-level jet will provided convergence in the vicinity of the front Sunday night with another round of thunderstorms possible from central Minnesota across central and northern Wisconsin into southern Upper Michigan. Temperatures will trend a little cooler for Thursday with highs in the 70s to low 80s. A little warmer Friday with highs in the upper 70s to low 80s, then low to middle 80s for Saturday through && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 642 PM CDT Tue Jul 3 2018 Most of the Northland was dry early this evening with an isolated light shower over southern Koochiching County. Most of the cloud bases were VFR but there were some MVFR in spots. Overall we expect showers and storms to increase in coverage through the evening, especially over western areas, with an expansion to the east later tonight. Some of the storms could be strong to severe as a very moist and unstable airmass is over the Northland. Some fog will be possible later tonight as well and the fog and storms will create a period of MVFR or possible IFR conditions. Storms may be ongoing over parts of the Northland Wednesday morning with more expected as a low/frontal boundary move into the region during the day. Timing in the TAFs will be refined as we progress through the night. && .PRELIMINARY POINT TEMPS/POPS... DLH 59 81 61 78 / 20 80 40 0 INL 67 82 58 74 / 60 60 20 0 BRD 69 84 63 79 / 30 60 30 0 HYR 68 88 66 81 / 10 60 50 10 ASX 61 86 63 79 / 10 70 50 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...Flood Watch through Wednesday evening for MNZ010-011-018-019-025- 026-033>035. LS...None. && $$ UPDATE...JJM SHORT TERM...Melde LONG TERM...Huyck AVIATION...Melde
Area Forecast Discussion
National Weather Service Green Bay WI
1048 PM CDT Tue Jul 3 2018 Updated aviation portion for 06Z TAF issuance .SYNOPSIS... Issued at 231 PM CDT Tue Jul 3 2018 Very warm and humid with a chance of thunderstorms on the Fourth of July, and a better chance Wednesday night. The main belt of westerlies will remain across Canada and the far northern United States during the forecast period. The flow will gain modest amplitude at times and flatten back to nearly zonal at others. The forecast area will remain near the southern edge of the westerlies, with the upper flow across the area shifting back and forth between southwest and northwest in response to the passage of major shortwaves to our north. Very warm and humid conditions tomorrow into Thursday will give way to a period of more seasonable temperatures and less humid conditions for the end of the week and upcoming weekend. But temperatures and humidities will probably trend upward again early next week. The overall pattern seems to favor AOB normal precipitation for the next week. But totals will be dependent on the specifics of convection and the inherent uncertainty related to that. && .SHORT TERM...Tonight and Wednesday Issued at 231 PM CDT Tue Jul 3 2018 The latest RAP analysis and satellite/radar imagery show an area of low pressure over the eastern Dakotas, with an associated warm front extending southeast from southern Minnesota to southern Lake Michigan early this afternoon. Convection continues to develop north of the warm front over Minnesota, sending a cirrus shield northeast over north-central WI. Short range guidance continues to indicate that these clusters of storms will either weaken or pass by the area to the west and north later this afternoon due to a more stable airmass further east. Low level moisture is increasing, however, over southern WI where cu is becoming more widespread. As this hot/humid airmass arrives, forecast concerns revolve around fog potential tonight, and thunderstorm potential on Wednesday. Tonight...As a cold front moves east over the far northern Plains, mid-level heights will continue to rise over the western Great Lakes. This will keep the low level jet and elevated moisture transport axis to the northwest of the region, which should therefore result in mostly clear conditions for much of the evening. As the surface warm front arrives late, increasing low level moisture will lead to the threat of fog development. Guidance has different views on fog potential, but with light boundary layer winds, some lower visibilities remain possible. Went with the greatest potential west of the Fox Valley, where the short range guidance is pin-pointing. Mild lows ranging from the low to mid 60s. Wednesday...With steepening low level lapse rates and ample moisture, progged soundings suggest that any fog and/or low stratus will evolve into a fairly widespread cu field by mid to late morning. Convective temps are relatively low tomorrow, in the mid to upper 80s, and combined with ml capes in the 2-3k j/kg range, isolated to scattered showers and storms are expected to develop with the heat of the day. Guidance actually points towards areas over and just west of the Fox Valley as having the best chance of precip, which matches well with the previous forecast, so only made cosmetic changes. Peak heat indices will approach 100 degrees over parts of central and northeast WI. But with the clouds and potential rainfall, decided against issuing a heat advisory, with additional collaboration from neighboring offices. Highs ranging from the mid 80s to low 90s away from Lake Michigan. .LONG TERM...Wednesday Night Through Tuesday Issued at 231 PM CDT Tue Jul 3 2018 Precipitation chances Wednesday night are a key aspect of the forecast because of all the Fourth of July fireworks displays that are scheduled for dusk. Some storms from the afternoon could certainly linger into the evening, but the coverage of those should decrease with the loss of heating, so much of the area will be dry during the early evening. A better chance for storms will come later in the night as a cold front approaches and then begins to push through the area. The front probably won`t arrive in the area until late--well after the boundary layer begins to stabilize with the loss of heating. The most likely convective scenario is for storms to fire/focus along the front west of the area late Wednesday, then weaken as they push into the area during the night. They may even fall apart completely before reaching eastern Wisconsin. The mid-day convective outlook update from SPC edged back the severe risk a little by pulling the slight risk west of the area. That seemed reasonable given the time of arrival of the front. North-central Wisconsin is most at risk of having storms from the west move in early enough to disrupt fireworks displays. Thunderstorms chances Thursday will depend on how quickly the front clears the area and whether or not the atmosphere gets completely overturned by storms Wednesday night. The greatest chance of storms Thursday will be over east-central Wisconsin (especially if the Wednesday night storms fall apart before reaching this area). The severe risk looks limited, though some potential may exist for wet microbursts, especially if the front is slow to clear the area. Lower humidities and more seasonable temperatures are expected for Friday into the upcoming weekend. Overall, the standard extended forecast initialization grids based on a broad blend of guidance products seemed to adequate, so few adjustments were necessary. && .AVIATION...for 06Z TAF Issuance Issued at 1026 PM CDT Tue Jul 3 2018 Mostly clear skies will rule over the TAF sites overnight. However, increasing low-level moisture should lead to an increase in fog and low clouds late tonight, though the areal coverage of MVFR/IFR conditions remains uncertain. So far there is not much of a reason to deviate from the previous forecast. Any low visibilities should improve relatively quickly during the morning, but cigs may take until mid-morning until they reach vfr status. Shower and storm chances will increase from about late morning through the evening hours. Storms in the afternoon will mainly be due to instability, while storms in the evening will be associated with an approaching cold front and mid level shortwave. Therefore rain chances will be higher Wednesday evening and lower during the afternoon. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......Skowronski SHORT TERM.....MPC LONG TERM......Skowronski AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
746 PM PDT Tue Jul 3 2018 ...Updated Air Quality Section... .SYNOPSIS...A trough of low pressure will move into the region and provide some cooling through Wednesday. A strong ridge of high pressure will build into the region and bring hot and dry conditions for the weekend. Warm and dry weather is expected to persist into next week. && .PREV DISCUSSION... /issued 408 PM PDT Tue Jul 3 2018/ .DISCUSSION... Some cumulus clouds along the sierra mountains, otherwise clear and dry conditions. Satellite images show smoke aloft over much of the central CA interior. Some clearing taking place towards Pacheco pass and Merced due to the onshore marine flow. Some breezy conditions with local gusts to 35 mph are likely at times through this evening along the west side of the SJ Valley. Breezy conditions are also possible over eastern Kern County, including in the mountain/desert areas. HRRR smoke models shows some smoke coming down from the County fire tonight and dispersing in the afternoon due to stronger SW wind flow. Models indicate an upper level trough will set up off the Pacific Northwest coast and provide SSW wind flow. This flow will be onshore maritime and dry flow and mitigate any rapid heat up. However a ridge of high pressure begins to build from the desert SW Thursday. Temperatures will begin to warm Thursday and especially over the Kern County Desert on Friday. Further warming will occur throughout Central California through the weekend due to the ridge expanding Northward. Global models prog for some weakening of the ridge over the Desert SW and Rockies, and hinting for a push of southeasterly flow with some monsoonal moisture towards the Colorado River Basin late in the weekend and next week. For now, will keep the forecast dry through next week with generally warmer than average temperatures. && .AVIATION... VFR conditions will prevail across the Central CA Interior during the next 24 hours. && .AIR QUALITY ISSUES... Please see SFOAQAHNX for an Air Quality Alert. On Wednesday July 4 2018... Unhealthy for sensitive groups in Kern County. Further information is available at && .CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit for additional information an/or to provide feedback. && .HNX Watches/Warnings/Advisories... Excessive Heat Watch from Saturday morning through Sunday evening CAZ089>095-098-099. && $$ public...Durfee avn/fw...Durfee prev discussion...MV synopsis...Durfee
Area Forecast Discussion
National Weather Service Jacksonville FL
917 PM EDT Tue Jul 3 2018 .UPDATE... Most of the convection has moved well west of the forecast area with a few showers moving in from off the ocean embedded in the easterly flow. With the upper level low moving west toward the area will see a break in the showers for a few hours but developing bands of showers noted on satellite imagery east of the Gulf Steam will move west toward the coast between 2 and 6 a.m. The HRRR is indicating those showers will consolidate into a pretty robust band and move onshore during the sunrise/early morning period. So overall a pretty quiet night inland with a few coastal showers for most of the night and then a better chance of coastal showers and thunderstorms toward sunrise. && .AVIATION... Most of the local fields will remain quiet overnight with VFR conditions in the prevailing groups. We may see a few showers in the vicinity of the Northeast Florida Regional Airport (KSGJ) all night but between 04 and 08 utc showers over the coastal waters will become more numerous with a better chance of tempo conditions at the coastal sites. Brief visibility restrictions of 4-6sm in showers will be possible at KSSI and KSGJ. Between 08 to 12 utc the showers will become more widespread and will impinge on all of the coastal areas with brief heavy rainfall possible in all over the coastal and Jacksonville metro fields. Right now looking at 2-4sm visibility with ceilings of 3-5 kft possible in a tempo group. && .MARINE... High pressure well to the northeast of the area will maintain an easterly flow across the coastal waters with no headlines expected. An upper level disturbance moving westward across the area will push showers and thunderstorms westward across the region through Thursday. Rip Currents: Moderate risk at area beaches through Thursday. && .PRELIMINARY POINT TEMPS/POPS... AMG 93 74 89 71 / 40 30 60 20 SSI 87 77 86 76 / 20 50 60 30 JAX 90 74 88 73 / 30 50 60 20 SGJ 87 75 86 73 / 30 40 50 30 GNV 91 72 89 71 / 40 30 60 20 OCF 91 72 89 71 / 50 20 60 40 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ Sandrik/Kennedy/Bricker
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
811 PM CDT Tue Jul 3 2018 .UPDATE... Issued at 810 PM CDT Tue Jul 3 2018 Examination of new runs of the HRRR for tomorrow afternoon indicate that high temperatues will likely reach the mid 90s across central and northeast Missouri as well as west central Illinois. At the same time, dewpoints will likely stay in the mid 70s resulting in heat index readings reaching around 105. Because of this, went ahead and issued a heat advisory for the remaining counties just for tomorrow afternoon and early evening. Otherwise, thunderstorms have diminished around the St. Louis metro area, but and moved back into southeast Missouri and southwest Illinois. Expect them to diminish the next couple of hours with the loss of daytime heating. Britt && .SHORT TERM... (Through Late Wednesday Afternoon) Issued at 350 PM CDT Tue Jul 3 2018 South and southeast surface flow continues to result in the gradual return to the uncomfortably warm and humid airmass. Afternoon surface instability in conjunction with weak mid to upper level ascent has given rise to isolated to widely scattered showers and thunderstorms. Activity has been fairly tame so far. However, some storms have briefly produced lightning and localized heavy downpours. DCAPE values in excess of 1000 J/kg over much of the area suggests that any of the deeper storms will be capable of gusty winds. given the lack of shear, severe weather is not anticipated and development will be relatively short-lived. Storms are likely to quickly dissipate around and after 8pm. The upper ridge to the east continues to build westward on Wednesday. Once again, high res guidance picks up on another weak disturbance around the western periphery of the ridge, along with the slow moving boundary. As this lifts north, a few showers and isolated storms will be possible north of I-70, especially around and northeast of Quincy during the early afternoon. Main topic will be the heat. Wednesday afternoon/evening temperatures and dewpoints will combine to result in dangerous heat indices in excess of 105. Anyone with outdoor plans should consider taking extra precautions to mitigate heat related illness. Maples .LONG TERM... (Wednesday Night through Next Tuesday) Issued at 350 PM CDT Tue Jul 3 2018 On Thursday, a cold front will approach from the northwest, but given the speed of the front, most of the area will still experience highs in the mid-90s with heat index values at or above 105. The exception may be the northern portion of the CWA where possible showers and storms associated with the front may dampen highs; however, the current heat advisory coverage looks appropriate. For Friday, the cold front will slowly move southward through the forecast area during the day. Showers and storms are possible along and south of the front as it pushes through the area, with pops tapering off from north to south during the afternoon and early evening. Due to the passing of the front and clouds associated with the convection, highs will be lower than those of the previous few days; only reaching the mid- to upper-80s. Behind this front, north- to-northeasterly flow aloft and at the surface will dominate this weekend, allowing for a relatively cool and dry air mass to settle in over the forecast area for Saturday and Sunday. Temperatures will top out in the mid-80s with dew points in the upper-50s to lower-60s for both days, making for pleasant conditions throughout the area. During the beginning of the work week, the surface ridge will move off to the east and southerly flow will return to the forecast area. This will boost high temperatures to around 90 on Monday and the low- 90s on Tuesday, with dew points in the mid-70s both days. This will create and unstable air mass that will introduce the possibility for isolated convection both days, but specifics on timing and coverage will have to wait until that part of the forecast period draws closer. Elmore && .AVIATION... (For the 00z TAFs through 00z Wednesday Evening) Issued at 617 PM CDT Tue Jul 3 2018 Scattered thunderstorms affecting the St. Louis area terminals are expected to diminish across the area by 01Z. Then dry and VFR conditions are expected through the night. A weak storm system will move across northern Missouri and west central Illinois early on Wednesday morning bringing a chance of thunderstorms to KUIN. Any storm could bring MVFR/possible IFR conditions and brief downpours. Dry and VFR conditions are expected at the rest of the terminals. Winds will generally be light outside of storms. SPECIFICS FOR KSTL: Thunderstorms in the vicinity of the terminal will diminish by 01Z. Otherwise mainly dry and VFR conditions are expected the rest of the period with light winds. Britt && .LSX WATCHES/WARNINGS/ADVISORIES... MO...Heat Advisory from noon to 8 PM CDT Wednesday 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 from noon Wednesday to 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 from noon to 8 PM CDT Wednesday for Adams IL-Brown IL-Pike IL. Heat Advisory from noon Wednesday to 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 Charleston WV
1028 PM EDT Tue Jul 3 2018 .SYNOPSIS... The heat is on today through Thursday, with unsettled conditions. Cold front crosses Friday night. High pressure for the weekend. && .NEAR TERM /THROUGH WEDNESDAY/... As of 1020 PM Tuesday... Convection likely finished for the evening and overnight so have removed any POPs going forward. Reworked the temperatures overnight for locations that had rain and clouds. As of 235 PM Tuesday... Morning debris clouds finally burning off per surface reports and satellite imagery. This has held our warmup in check, especially across the Kanawha Valley and along the I77 corridor. Seeing general flat cu field over the eastern mountains. By around 21Z, we may see some convective initiation from KCKB-KEKN and down into Webster and Nicholas Counties as per modest cu enhancement noted on visible imagery in these areas and latest HRRR runs. Otherwise, current thinking is most of the remaining forecast area should remain precip free through tonight. Atmospheric flow is weak and synoptic scale conditions will not change much over the next 24 hours. Will see minor 5h height rise and some influx of warmer air for Wednesday with slight uptick in max temps expected. Upgraded to Excessive Heat Warning for central WV and SE OH, with advisories for peripheral counties for Wednesday, a hot and humid Fourth of July. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... As of 330 PM Tuesday... The environment will be dominated by sfc high pressure to the west, and high pressure ridge aloft during the beginning of the period. Any shower or storm that develops under afternoon heating and orographic lift, will dissipate quickly Wednesday night. The high pressure moves over the Atlantic coast, but still influenced the local weather with a very loose pressure gradient and relatively dry conditions. It will be hot, with lowland temperatures in the mid 90s and dewpoints in the 70s Thursday. Models suggest no pcpn is expected through Thursday, although can not rule out a summer shower or storm during the maximum heat hours. Nevertheless, heat indices are expected once again to reach the lower 100s Thursday for when at least a Heat Advisory will be needed. By Thursday night, a cold front will approach from the west bringing likely and categorical PoPs through Friday. The cold front is expected to exit south and east by late Friday night. Expect numerous showers and storms ahead and along the front Friday. High bouyancy and low deep layered shear will keep severe threat low. However, PWATs will increase to 2.25 inches. Under this environment, any storm that develops with contain heavy downpours due to the high moisture content air, and be slow to move, thereby keeping the threat for localized flash flooding issues a concern. Will monitor these conditions closely to provide updates from new guidance. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 330 PM Tuesday... Behind the aforementioned cold front, a broad high pressure, centered over the Great Lakes region, will expand east and south to protect the OH VAlley and WV will dry conditions through the end of the period. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... As of 740 PM Tuesday... VFR continues this evening, although VCTS affecting CKB in the first 90 minutes of the TAF. Guidance has not been handling the fog potential well over the past few nights at all, but did go ahead and commence with deteriorating conditions late in the overnight with 2-4 hours of LIFR fog at all sites except BKW, and slightly sooner for EKN and CKB where some rain has fallen. Otherwise, VFR returns during the day Wednesday with winds under 10kts. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing and extent of fog in question tonight. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE WED 07/04/18 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY H H H H H H H H M H M L HTS CONSISTENCY H H H H H H L L H H H L BKW CONSISTENCY H H H H H H H H H M M M EKN CONSISTENCY H H H H M H H M M M M M PKB CONSISTENCY H H H H H H H H L M M M CKB CONSISTENCY H H H H H H H M H H H L AFTER 00Z THURSDAY... Brief IFR in scattered afternoon and evening thunderstorms Thursday, and then more widespread showers and thunderstorms Friday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...Excessive Heat Warning from noon to 8 PM EDT Wednesday for WVZ005>009-013>015. Heat Advisory from noon to 8 PM EDT Wednesday for WVZ010-011- 016>020-024>031. OH...Excessive Heat Warning from noon to 8 PM EDT Wednesday for OHZ066-067-075-076-083>087. KY...Excessive Heat Warning from noon to 8 PM EDT Wednesday for KYZ101>103-105. VA...None. && $$ SYNOPSIS...KMC/ARJ NEAR TERM...KMC/26 SHORT TERM...ARJ LONG TERM...ARJ AVIATION...26