Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/20/18

Area Forecast Discussion
National Weather Service Cleveland OH
947 PM EDT Tue Jun 19 2018 .SYNOPSIS... A cold front just south of the region will stall in central Ohio this evening. Weak low pressure moving east along the boundary overnight will force the front north into the region early Wednesday before dropping south again Wednesday afternoon and evening. The front will return again towards the end of the week, forced north by another low approaching from the west. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... The precip over the area continues to fall apart which isn`t surprising given the dry low level easterly flow. Still there is a decent shot for showers overnight as a weak surface low tracks across the local area. However...the threat for strong thunderstorms and locally heavy rainfall is diminished. Best chances for widespread showers will be toward daybreak. No changes to temps. Previous...The cold front is now well south of the area extending from Iowa east across central Ohio. Convection has developed invof the boundary south and west of the area. Radar however shows another batch of convection tracking east across southern lower MI. Have followed the HRRR which track this ese onto the western counties late afternoon. Convection could continue to drift ese as it weakens. Otherwise have held onto chance pops south/southwest through the evening given current proximity. Overnight models bring good moisture back from the wsw as weak low pressure moves into western OH forcing the front back north as a warm front. By 12Z wednesday the front should again be in the area. Will increase pops through the chance category overnight west to east with likely pops for the southern half of the area on Wednesday and chance north. For the afternoon the front will again begin to track south in the wake of the low moving east. This will draw drier more stable air in from the north esp mid/late afternoon. Wednesday highs in the 70s. Lows tonight low to mid 60s and Wednesday night a few degrees lower. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... The overall pattern is changing and trending toward a deep upper level low pressure system that will be nearly vertically stacked as it approaches the forecast area. The upper level low pressure system will dive southeast into the middle Mississippi Valley region by Thursday and then shift northeast over Ohio by Saturday. Meanwhile, the upper level low will trend toward filling slightly and become a negatively tilted trough over the area. This will force the surface low to lift northeast across the area Friday into Saturday. Copious amounts of moisture appears that it will get wrapped up into the system and the threat for an extended period of rain can be expected Friday and Saturday. Rainfall amounts of between a half an inch to around an inch is possible during the two day period. At this time, it appears CAPE values will be fairly low limiting the threat for thunderstorms. This precipitation should be primarily stratiform type rain with the storm system. Warm front in advance of the storm system is expected to move north through the area and not get hung up as a stationary front causing heavy rainfall. Temperatures through the forecast period expected to hover in the 70s for highs each day and lows in the 60s with the cooler air in place and then precipitation and cloud cover cooling effects for Friday and Saturday. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Models are in pretty good agreement on the overall pattern Saturday night into early next week. Low pressure over the eastern Great Lakes Saturday night will be pushing east and moving into New England by Sunday morning. Lingering precip may impact the eastern half of the area during the evening with mainly dry conditions across the area overnight. A backdoor cold front will sink south through the Great Lakes Sunday, but will wash out as it moves into the local area. Have continued with slight chance/low chance pops Sunday across the area. Dry conditions are expected by Sunday evening with high pressure building south through the Great Lakes into the region. The high will remain over the region through at least Tuesday providing dry conditions and more seasonable temperatures. Highs during the period will be near or slightly below normal in the mid to upper 70s Sunday and Monday and the upper 70s to low 80s by Tuesday. Lows will generally be in the upper 50s to mid 60s. && .AVIATION /00Z Wednesday THROUGH Sunday/... Lot`s of precip heading toward the area but the first wave may dissipate as it runs into the dry easterly flow at low levels. A wave of low pressure will move across the area overnight and better chances for showers exist late tonight. For the next couple of hours will put some tempos in at FDY and MFD. Overnight all areas will get a mention. Not sure about thunder chances given the expected weakening but FDY may have a chance the next couple of hours. CIGs will become MVFR behind the low. Similar to today it may take much of Wednesday for things to return to VFR. Light easterly flow will become light and variable for a time then N to NE on Wed. OUTLOOK...Non-VFR Tuesday through Wednesday and again Friday into Saturday in showers and thunderstorms. && .MARINE... Lot of marine headlines up at this moment with winds out of the northeast at 15 to 25 knots from about just east of Cleveland up to Erie. Small craft advisory and beach hazards will persist until about 8 PM when winds are expected to diminish below criteria. The northeast flow is also causing water levels to rise on the west and a lakeshore flood warning is now in effect until 8 PM this evening. Expecting water levels to continue to rise this afternoon with the gusty winds on the lake. Winds will increase again Wednesday morning from the northeast at 15 to 25 knots and will likely need another small craft advisory for a brief period Wednesday morning into early afternoon. Winds diminish again for Wednesday night out of the northeast and then gradually shift to an easterly direction by Thursday night. As a deep low pressure system approaches from the southwest Friday winds will shift back to the southeast and begin to increase. The low will move northeast of the area by Saturday and shift the flow around to westerly and then northwest by Sunday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...TK NEAR TERM...TK/Kubina SHORT TERM...Lombardy LONG TERM...Greenawalt AVIATION...Kubina MARINE...Lombardy
Area Forecast Discussion
National Weather Service Quad Cities IA IL
705 PM CDT Tue Jun 19 2018 ...AVIATION UPDATE... .SYNOPSIS... Issued at 244 PM CDT Tue Jun 19 2018 18z surface data has an implied low in northwest Iowa. A front extended from the low to just south of KMLI and then east into northern Indiana. A possible meso low was along the front between KMLI and KC75. Dew points were in the 70s from the Ohio Valley into eastern Nebraska on south to the Gulf Coast. Dew points were in the 50s and 60s from the Great Lakes into the northern Plains. && .SHORT TERM...(This Evening through Wednesday) ISSUED AT 244 PM CDT Tue Jun 19 2018 Through sunset, forcing from last nights nocturnal thunderstorm complex will move east toward Indiana. Areal coverage of showers and thunderstorms will slowly decrease from west to east. Due to the high moisture content in the atmosphere, any storm will be capable of producing heavy rainfall. Based on radar trends, storms will probably remain progressive which should prevent rainfall from becoming excessive in any one location. After sunset, showers and thunderstorms will be possible through sunrise Wednesday. Another nocturnal thunderstorm complex is expected to develop. However, all models disagree on where this development will occur. RAP trends point toward central and eastern Illinois. The UKMET tries to develop a nocturnal complex in eastern Nebraska/western Iowa that slowly moves east southeast. Giving a nod to the UKMET, will go with the idea of another nocturnal complex developing in western Iowa that moves southeast into northeast Missouri. For Wednesday the key will be where the frontal boundary stalls. This stall will be influenced considerably by the thunderstorm complex from Tuesday night. Internally the models suggest the boundary stalling across the southern third of the area. If correct this boundary would then provide the focus for storms to persist/develop during the day. As a result, the highest pops Wednesday are across the southeast half of the area. .LONG TERM...(Wednesday Night through Tuesday) ISSUED AT 244 PM CDT Tue Jun 19 2018 Turning cooler with episodes of showers and non-severe storms through the period. Long Term Forecast Confidence Assessment...fair to poor or average to below average. Main issue is coverage and amount of precipitation Thursday and Friday. Amounts may be locally up to 1 plus inches over a 48 hour period with impacts on area highs and lows. Forecast highs and lows may be off by 5 plus degrees over one or more days depending on cloud cover with unsettled conditions into next week. Thursday and Friday...lots of clouds with areas of showers and storms with heaviest amounts likely along and south of I-80 corridor. Forecast highs in the 70s seem reasonable with surface low passing south of area with mins upper 50s to lower 60s. Best estimates are light amounts far north with moderate to locally low end heavy amounts over a 24 plus hour period with little or no water issues and helpful for area plant growth. Saturday through Monday...mostly fair and seasonably cool with highs mostly in the 75 northeast to around 80 degree range south sections with moderate humidity levels. Mins in mid 50s to some lower 60s south sections or slightly below normal with isolated showers and maybe a brief storm in Northwest upper level flow. short wave to arrive with areas of showers and some thunderstorms suggested with limited instability suggested attm. Confidence better known on timing in next 24 hours but moderate to lower end heavier amounts are in long waver trough with mostly instability to our south. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) ISSUED AT 705 PM CDT Tue Jun 19 2018 Areas of MVFR/IFR conds through Wednesday morning then mainly VFR in the afternoon. Scattered thunderstorms developing late tonight and Wednesday, mainly south of Interstate 80. Mainly east winds less than 10 knots through this taf cycle. && .HYDROLOGY... Issued at 244 PM CDT Tue Jun 19 2018 Wapsipinicon River near DeWitt has crested and should fall below flood stage in about 48 hours or late Thursday or Thursday evening. Heavy rains of up to 6 inches in Stephenson County impacting the Rock River which may cause minor flooding at Joslin and Moline in next 36 hours. A Flood Watch has been issued for these two points as rivers have yet to respond with a chance a Flood Warning being issued in the next 12 hours as confidence and response becomes better clarified. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...08 SHORT TERM...08 LONG TERM...16 AVIATION...Haase HYDROLOGY...16
Area Forecast Discussion
National Weather Service Goodland KS
541 PM MDT Tue Jun 19 2018 .SHORT TERM...(This evening through Wednesday) Issued at 258 PM MDT Tue Jun 19 2018 Thunderstorms have developed along the front near our southeast edge. Also large area of storms have developed over eastern Colorado in a post frontal environment. Rather strong shortwave moving in from the west is helping storms develop as well. Shear, instability, and lapse rates are favorable for continued severe storms to develop and currently have a tornado and severe thunderstorm watches out covering the entire area through the evening. Parameters still in place for these storms to produce very heavy rainfall. Hrrr is capturing both the placement of storms and the intense rainfall they are producing. So flash flood watch looks good. Some lingering rainfall in the morning along with additional development afternoon will be possible in the afternoon. Not much time to look at that. However, mesoscale influences from ongoing convection could enhance that. Temperatures for Wednesday will need to be looked since could have a lot of wet ground and lingering cloud cover. .LONG TERM...(Wednesday night through Tuesday) Issued at 237 PM MDT Tue Jun 19 2018 Upper low currently over Idaho will migrate slowly into the mid- Mississippi Valley by Friday. As it does so, it will keep a lingering chance of showers and thunderstorms across the far northeast counties through Thursday morning. Once the upper low leaves the area, short wave ridging will temporarily move over the area Thu-Fri. A second upper trough will move quickly into the area Friday night with another chance of scattered convection. Later in the weekend a closed upper low will move from the Intermountain Region out over the High Plains with both the GFS and EC fairly consistent in location and timing. This will produce a chance for widespread convection from Sunday afternoon into Monday evening. Temperatures through the period will generally be near to above normal with highs mostly in the 80s but approaching 90 by Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 540 PM MDT Tue Jun 19 2018 Severe weather going on. Not enough time to do a discussion. When thunderstorms affect the sites, there will ifr to mvfr conditions. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Flash Flood Watch through late tonight for KSZ001>004-013>016- 027>029-041-042. CO...Flash Flood Watch through late tonight for COZ090>092. NE...Flash Flood Watch through late tonight for NEZ079>081. && $$ SHORT TERM...BULLER LONG TERM...DLF AVIATION...BULLER
Area Forecast Discussion
National Weather Service Northern Indiana
743 PM EDT Tue Jun 19 2018 .SYNOPSIS... Issued at 735 PM EDT Tue Jun 19 2018 Showers and storms will continue overnight tonight with the best chance for lingering showers south of US-30. Humidity continues overnight and into Wednesday, but Wednesday`s highs will be cooler than today`s. A chance of showers and a possible thunder will exist south of US-30 on Wednesday too. Thereafter, expect cooler temperatures to round out the work week while the next chance for showers and storms comes Friday and Friday night. && .SHORT TERM...(Tonight and Tomorrow) Issued at 217 PM EDT Tue Jun 19 2018 Vigorous storms developing quickly this aftn within a zone of substantial sfc based instability and weak forcing invof stationary frontal zone. Lack of flow/shear will keep potential storm severity in check however similar to last evening water loading within high moisture content airmass poses a local microburst threat especially along ern flank of small scale cold pools in more cluster convection. Bulk of near term activity expected to follow south of US30 with additional development later this aftn invof trailing outflow boundary extending swwd from short convective segment over srn MI. More uncertain scenario overnight with varying CAMS based solutions/evolutions. Near term convective overturning and stabilization after sunset suggests a waning in additional shower/storm development especially from late evening through Wed morning which lies counter to some deterministic solutions like the RAP which are much more bullish stemming from ewd progression of large scale disturbance out of IA. At the least will give a nod toward near term guidance/trends and knock likely pops down overnight. Passage of upstream disturbance will push frontal zone south into cntrl IN Wed. Some risk for additional showers south of US24 in Indiana mainly late morning into early aftn tied to diurnal heating/destabilization but focus appears much better through cntrl IN. Nonetheless drier and cooler across the remainder of the area within post frontal airmass. && .LONG TERM...(Thursday through Monday) Issued at 217 PM EDT Tue Jun 19 2018 Development of vigorous upper low over the mid MO valley and ewd evolution primary challenge this period. Surprisingly med range spectral solutions fairly similar aloft and suggest dry wx holds Wed night and Thu before active frontal zone bucks back north into the srn lakes Thu night with following showers/storms through Friday night. Ridging sfc and aloft then build through next weekend with moderating temps and dry wx. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 735 PM EDT Tue Jun 19 2018 Per SPC mesoanalysis page, the atmosphere appears relatively worked over with lacking low and mid level lapse rates. Still, over 1000 J/kg MUCAPE lingers in the area allowing for lingering thunderstorms with heavy rain and gusty winds as the main threat. Times of showers and storms are expected to continue during the overnight with heavy rain becoming the main threat especially as upper level divergence continues to the southeast and a shortwave approaches from the NW. Flight conditions will continue to recede towards low MVFR and possibly IFR as stratus builds in by Wednesday morning. Wednesday, a slightly more south-shifted boundary will continue to slowly shift south behind the departing low pressure system keeping the focus for any showers and possible storms mainly south of US-30. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...Roller SHORT TERM...T LONG TERM...T AVIATION...Roller Visit us at Follow us on Facebook...Twitter...and YouTube at:
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
945 PM CDT Tue Jun 19 2018 .UPDATE... 944 PM CDT Some fairly significant changes made to the overnight and early Wednesday portions of the forecast this evening, primarily to greatly reduce pops over much of the forecast area. Earlier strong convection across the southern parts of the cwa appears to have pushed the surface front south into central IL at mid-evening. Recent surface analysis places the boundary from roughly central Iowa, southeast into central Illinois and to just north of Indianapolis. Thunderstorms were generally south and southeast of the cwa at this time, focused along residual outflow and at least partly associated with a remnant MCV from this afternoon. RAP analysis does continue to depict a synoptic mid- level short wave trough propagating slowly east across the region, though convectively disturbed low-level flow from the surface up through 850 mb is generally from the north. In the absence of stronger southerly low level flow, potential for additional significant convective showers and thunderstorms appears fairly low. Have lowered pops significantly overnight, keeping higher chance pops across the far southeast through midnight, while maintaining only a slight chance mention elsewhere through the night. Have also lowered pops through the morning hours of Wednesday, as forcing remains negligible in the wake of the overnight mid-level short wave passage. Left Wednesday afternoon pops alone for now. Skies should remain mostly cloudy overnight, especially in the east and southeast parts of the forecast area. Any scattering of clouds would likely fill back in with stratus and/or fog, given moist boundary layer conditions and wet ground in many spots. Also, lowered min temps a bit overnight across far northeast IL, where modest north-northeast winds off the lake have already lowered readings into the lower 60`s. Updated digital grid/text forecast products already available. Ratzer && .SHORT TERM... 208 PM CDT Through Wednesday... Main concerns for the short term forecast period will be the coverage and intensity of thunderstorms. As of 2PM CDT, thunderstorms are becoming more organized invof a quasi-stationary frontal boundary currently analyzed along the Kankakee and Illinois Rivers. Latest radar imagery indicates increasing coverage in this area and expect that coverage should continue to increase through the remainder of the afternoon and into the evening. Pwats invof the boundary remain close to 2 inches and the ILX 12Z sounding shows wly winds at 20kt in the 925-850mb layer. Latest indices from the SPC mesoanalysis show Downdraft CAPE values of 1200 j/kg with a bulls-eye of +4 for the Non-supercell Tornado Parameter over Iroquois County. These parameters along with the high moisture content would suggest the potential for locally heavy downpours and strong wind gust potential. The area remains under a Marginal Risk for Severe Wx and a Slight Risk for Excessive Rainfall/Flash Flooding. Portions of the area, generally south of Interstate 80 will need to be monitored closely for possible strong wind gusts or flash flooding. While much of the activity is expected to be along and south of the front, generally south of I- 80, there is still a chance for some isold shra/tsra this afternoon/evening to the north of I-80, but coverage is likely to be sparse and any thunder not as strong to the storms to the south. The general trend for convective activity should be to become more suppressed to the south as high pressure over the Upper Mississippi Valley and western Great Lakes expands across the nrn IL/IN and Lake Michigan. Nely flow will dominate at the sfc, drawing cooler air inland into nern IL/IN bringing increasing low stratus and fog inland into the Chicago Metro Area. Under the spreading high pressure, the warm, moist conditions will be forced to the south and temperatures across the area are expected to be quite a bit lower than the past week, with highs tomorrow ranging from the upper 60s to lower 70s along the lake front to the middle 70s inland north of I-80 and low 80s south of I-80. Showers and thunderstorms will still be likely tomorrow, especially in the warmer, more humid air mass south of I-80. && .LONG TERM... 224 PM CDT Wednesday night through Tuesday... Low pressure developing over the Plains and a stalled out frontal boundary extending east from the low will be two of the key players locally for the remainder of the week into the weekend. Generally weak flow aloft and marginal lapse rates would limit the concern for severe weather and perhaps even thunderstorms through this period, as would the cooler northerly flow for most of the area on the north side of the surface boundary. PWATs do however remain on the higher side, toward the 90th percentile, so showers that manage to develop along the boundary could have the potential to produce heavy rain. This will continue to be monitored especially in southern portions of the forecast area nearer the expected frontal location. The existing WPC excessive rainfall outlooks cover this nicely. With mostly cloudy skies prevailing through this period, expect a reduced diurnal temperature swing, with daytime highs at times well below normal for some locations and overnight lows a bit warmer than normal. The coolest locations will of course be along the lake in areas of onshore flow. Models generally agree on slowly moving the stacked low across or just south of the area on Friday. They then show a weak ridge building in from the west through the first half of the weekend, with the local area initially remaining in the drier and cooler flow on its easterly side. Confidence gets much lower later in the weekend and into early next week, but a weak disturbance in the upper cyclonic flow could bring another chance of precip to the area Sunday, with upper ridging appearing to become more established by Monday. Lenning && .AVIATION... For the 00Z TAFs... The main forecast concern now focuses on the low CIGs and VSBYs likely to shift over all the terminals within the next 1 to 2 hours as cooler air shifts south in the wake of boundary shifting south into central IL. While there will be showers around this evening it does appear that the thunder threat should remain south of the terminals. Rain showers could linger into the early overnight hours as a decent mid-level disturbance gradually shifts overhead around midnight. Also can`t rule out a thunderstorm as this disturbance shifts overhead, but this will likely be localized and certainly not enough confidence to put the mention in the TAF. Otherwise, expect low CIGS to continue to overspread the area. As of this writing ORD was already in the IFR and this should continue to be the trend through the evening. It appears that CIGS could drop into the 300-400 foot range later this evening and overnight and into early Wednesday morning. We will also likely have some lower VSBYs down around 2 miles tonight as fog shifts inland off the lake. Conditions should improve through the morning, with VFR conditions likely to return to the area by Wednesday afternoon. Expect a north-northeasterly wind through the period. KJB && .MARINE... 311 PM CDT Despite persistent onshore flow from the north or northeast the nearshore waves appear to stay below small craft levels for the remainder of the week. This is due to the light wind speeds and fairly short fetch resulting from varying wind directions over the lake. If speeds increase or a longer fetch manages to develop then wave heights could approach advisory thresholds. A center of low pressure moving through the area Friday and Saturday will bring a more variable period of wind directions and wave heights through the weekend. Lenning && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Dense Fog Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745- LMZ777-LMZ779 until 10 AM Wednesday. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
943 PM CDT Tue Jun 19 2018 .UPDATE... Issued at 938 PM CDT Tue Jun 19 2018 The complex of showers and thunderstorms which tracked west to east across the area during the late afternoon and evening continues to weaken as it moves into southeast IL. Only a little thunder exists at this time in Fayette and Marion Counties with areas of stratiform rain lingering back in southwest/south central IL. All of this precipitation should continue to weaken as it moves east over the next few hours. The question for the remainder of the night is whether we will see additional showers and storms. We are monitoring the area back between St. Louis and Columbia. There is currently a shower near Williamsburg, which is located within an elongated zone of low level moisture convergence associated with an anticyclonically turning weak branch of the LLJ. This area is also within the cool sector of the outflow boundary that passed thru the area and within some weak elevated CAPE. The operational HRRR wants to really bloosom this region into a decent area of showers and storms over eastern MO, however it is overdone dramatically with coverage at this time. Uncertainty in the evolution is greater than normal and slight chance to chance pops seem appropriate given current trends. Glass && .SHORT TERM... (Through Late Wednesday Afternoon) Issued at 345 PM CDT Tue Jun 19 2018 Continued the heat headline through 7 pm cdt with heat advisory for central portions of CWA, and an excessive heat warning for the St Louis metro area. Heat indices have risen to 98-105F range over central CWA along MO river valley into St Louis metro and eastward into sw IL over Marion county, IL. Heat indices were in the 85-95F degree range over northern and southern CWA. An area of showers/thunderstorms was spreading ENE across northern CWA and into west central IL with a few strong to severe thunderstorms nw of the IL river. This convection was ahead of a frontal boundary over northern IL, central IA, se NE, nw KS to 1005 mb surface low pressure in southeast CO. Unstable airmass over area with CAPES of 1500-2500 j/kg and a weak wind shear environment, so storms are pulse type microbursts. Marginal risk of severe wind gusts from I-70 north into early evening. Increased chances of convection over northern CWA into mid evening, then becomes more widely scattered overnight. Just isolated convection over southern CWA through tonight. Lows overnight of 70-75F, warmest in the St Louis metro area. Isolated convection Wed morning to become more widespread during Wed afternoon as airmass destabilizes again as cold front moves toward nw CWA by days end as strong upper level ridge continues to weaken over MO and mid MS river valley as its suppressed southward. SPC day2 outlook as marginal risk of severe storms far western CWA for Wed afternoon/evening. Highs 85-90F on Wed with afternoon heat indices in the low to mid 90s. KMH .LONG TERM... (Wednesday Night through Next Tuesday) Issued at 345 PM CDT Tue Jun 19 2018 A 573 dm 500 mb low over western MT tracks into sw IA/nw MO by Thu morning and into IL on Friday as it deeps a bit more to 570 dm. This system has ample moisture to work with and will bring unsettled weather pattern to area from Wed night through Friday with fairly high chances of showers and thunderstorms. Locally heavy rains will also be possible especially from I-70 north. Temps continue to cool due to more cloud cover and more widespread convection. Highs in the low to mid 80s Thu and upper 70s/lower 80s Friday. Cutoff upper level low shifts east across the Ohio river valley Friday night, with convection chances diminishing Fri evening over our CWA. Small pops over ne CWA Fri evening and over southern CWA on Sat afternoon, while much of CWA to enjoy dry weather. Highs Sat of 80-85F. Weak low pressure to track from the Ozarks into the mid MS river valley from Sat night into Sunday and return chances of showers and thunderstorms to eastern MO and sw IL. Chances of convection linger se half of CWA Sunday evening, then briefly dry overnight Sunday night into Mon morning. Highs Sunday in the low to mid 80s. 12Z models are building an upper level ridge into the mid MS river valley early next week, with keeping convection chances low. Temperatures and humidity levels rising with highs next Tue in the mid to upper 80s and dewpoints in the upper 60s/lower 70s. KMH && .AVIATION... (For the 00z TAFs through 00z Wednesday Evening) Issued at 627 PM CDT Tue Jun 19 2018 A broken band of showers and thunderstorms will impact the St. Louis terminals thru around 02z with gusty winds to 35 kts and flight conditions ranging from MVFR-IFR. After this activity moves east and also for the remainder of the terminals, VFR flight conditions should prevail at least into the first part of the overnight period. There is some uncertainty on additional showers and thunderstorms overnight and into early Wednesday morning. Currently the chances are low. The greatest probability at this time appears to be at KUIN and hence have added a VCTS at 10z. Shower and thunderstorm chances should increase during the later part of Wednesday morning and into the afternoon. Any thunderstorm directly impacting a terminal could bring gusty winds and lower flight conditions. Outside of the showers and thunderstorms, VFR flight conditions are expected. SPECIFICS FOR KSTL: A broken band of showers and thunderstorms will impact KSTL thru around 02z with gusty winds to 35 kts and flight conditions ranging from MVFR-IFR. After this activity moves east, VFR flight conditions should prevail. There is some uncertainty on additional showers and thunderstorms overnight and into early Wednesday morning. Currently the chances are low and thus nothing has been mentioned in the TAF. Shower and thunderstorm chances should increase during the later part of Wednesday morning and especially into the afternoon. Any thunderstorm directly impacting the terminal could bring gusty winds and lower flight conditions. Outside of the showers and thunderstorms, VFR flight conditions are expected. Glass && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Marquette MI
735 PM EDT Tue Jun 19 2018 .SHORT TERM...(This evening through Wednesday) Issued at 402 PM EDT TUE JUN 19 2018 WV imagery and RAP analysis indicated a mid/upper level low over Montana, a ridge over the se CONUS and a trough over ern Canada resulting in confluent wnw flow through the nrn Great Lakes. At the surface, a weak ridge extended through the nrn Mn through nrn Great Lakes bringing light ne winds with prominent lake breeze development. Some mid/high clouds have moved into nw Upper Michigan. Otherwise, only sct-bkn inland cu prevailed. Tonight, afternoon dewpoints in the lower 50s suggest that with another night of favorable radiational cooling, min temps should drop to around 50 with some isold colder locations. Wednesday, a weak shortwave moving through nrn Ontario will drag a weak cold front through Lake Superior in the afternoon and into Upper Michigan late. Although temps may drop off north with the frontal passage, there will be little additional impacts. With 850mb temps to around 14C, expect highs to around 80 inland 60s near the Great Lakes. & .LONG TERM...(Wednesday night through Tuesday) Issued at 410 PM EDT TUE JUN 19 2018 No significantly impactful weather expected in the long term. There was no need to make any changes to the blended initialization, which was also similar to the previous forecast. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 733 PM EDT TUE JUN 19 2018 With a dry air mass over the area, VFR conditions will prevail at KIWD/KCMX/KSAW thru this fcst period. Winds will be under 10kt. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 402 PM EDT TUE JUN 19 2018 Winds will stay at or below 20 knots through the forecast period. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...Titus AVIATION...Rolfson MARINE...JLB
Area Forecast Discussion
National Weather Service Raleigh NC
1011 PM EDT Tue Jun 19 2018 .SYNOPSIS... A ridge of high pressure over the southeastern United States will shift south but largely persist through the work week. A cold front will drift int the region on Wednesday and linger through Thursday before lifting north late Friday. .NEAR TERM /THROUGH TONIGHT/... As of 1010 PM Tuesday... ...Heat Advisory in Effect from 11 AM to 8 PM Wednesday for the Sandhills, the southern Coastal Plain and the eastern Piedmont... An outflow boundary coming into the northeastern Coastal Plain will be the focus for any remaining showers this evening which has been tracking southward out of VA for some time. Showers and thunderstorms have been characterized by moderate to heavy rain at times with a modest amount of lightning but have remained well below severe limits. Would expect the same to remain true as it moves into northeastern NC. Latest run of the HRRR shows showers making it to just north of the Triangle area before dissipating overnight. So far the HRRR has been too late and a bit underdone with the activity so it is reasonable that the convection makes it a little further south before fizzling out. Later tonight, there is an outside chance of MVFR fog/low stratus across the northeastern counties just before sunrise. Overnight lows in the low to mid 70s. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... As of 315 PM Tuesday... The upper-level ridge shifts south on Wednesday and Wednesday night resulting in falling heights across the Carolinas. As the ridge shifts south, the westerlies aloft strengthen across the area and a progressive short wave trough moves from the OH Valley into the mid-Atlantic during the afternoon and evening. In addition, the southward advancing cold front across the mid- Atlantic should have reached the northern/northeastern part of the CWA by Wednesday morning and stalled with convective outflow from tonight`s convection likely extending further southwest into the RAH CWA. Expect scattered showers and storms to develop again on Wednesday, with the greatest coverage across the northern and northeastern portion of the CWA, in proximity to the surface boundary. Stronger flow aloft will result in 0-6km shear of 20-30 kts which combined with a weak to moderately unstable air mass, could result in some storm organization in the form of some multicells and clusters and the risk of a few strong to severe storms across the northeastern counties. Low-level thicknesses and H8 temperature relax a bit on Wednesday as the ridge shifts south. Highs on Wednesday should range a couple of degrees cooler than today with highs on Wednesday in the lower 90s north to mid 90s south. Heat index values will approach criteria again on Wednesday afternoon across the southeast. Removed Halifax, Edgecombe, Nash and Franklin from the advisory tomorrow as the cooler air mass near the front should hold temps back in those area. Still muggy on Wednesday night with lows in the 72 to 77 range. -Blaes && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... As of 350 AM Tuesday... Low-level thicknesses and H8 temps begin to wane Wednesday in response to the de-amplifying and southward suppression of the the mid/upper level ridge into the Deep South/eastern GOM. Thus, highs Wednesday should average a few degrees cooler than today. Highs ranging from lower 90s north to mid 90s south. When combined with the 70 degree dewpoints, heat indices across the Sandhills and southern and central Coastal Plain counties will once again range between 103 to 107 degrees. As such, we will likely need to issue another heat advisory on Wednesday for much of the same area. Isolated to scattered diurnal convection should once again develop near the lee surface trough Wednesday afternoon. The northern/northeastern tier counties have the potential to see a period of likely pops during the late afternoon/early evening, where closer proximity to a quasi-stationary west-east frontal boundary and associated convection/outflow extending across the Mid-Atlantic region could propagate south into the area. Enhanced sheared to the north along the front, could result a few strong to severe storms across the northeastern counties. Lows Wednesday night in the lower to mid 70s. && .LONG TERM /THURSDAY THROUGH TUESDAY/... As of 400 PM Tuesday... Pattern overview: A complex mid-upr level low over the nrn/cntl Rockies will amplify sewd across the cntl Plains through Thu, then reach the mid MS Valley by 12Z Fri. Preceding, and influenced by that low, a portion of a mid level low now over srn TX will eject/shear shear newd across the TN Valley Thu, and srn and cntl Appalachians Thu night. The models indicate the parent low amplifying from the nrn Rockies to the mid MS Valley will then lift newd across the OH Valley and lwr Great Lakes on Sat, with associated glancing forcing for ascent and seasonably strong, 30-40 kts of swly mid level flow forecast Sat over cntl NC. Modest, quasi- zonal to broadly cyclonic flow aloft will then prevail across NC ahead of a strong nrn stream shortwave trough forecast to sweep off the Northeast and nrn middle Atlantic coast on Mon. Following ridging aloft is then forecast to build from the lwr MS Valley to the cntl Appalachians through the middle of the week. At the surface, the synoptic frontal zone now draped from the middle Atlantic coast wwd across the OH Valley, will settle swd and merge/overtake a preceding lee low over NC Thu, then become quasi- stationary in the vicinity of cntl/ern NC Thu night-Fri. This frontal zone will then retreat nwd once again with subsequent Appalachian-lee troughing through the weekend. A following cold front is then forecast to cross the srn middle Atlantic states on Mon, followed by high pressure that may curb the heat and humidity by Tue. But the likelihood of a front making a complete passage through NC this time of year is relatively low, as is predictability in general at Day 7. Sensible weather: Above average temperatures are most likely to be interrupted behind the aforementioned two (partial) frontal passages, on Fri and Tue. Precipitation/convective chances will also be maximized along those fronts, particularly late Thu-Fri. Environmental shear in the presence of the front Fri may also favor a semi-organized storm mode and marginal risk of severe weather during that time. Mainly diurnal convection, with slight to low chances, is otherwise anticipated throughout the period. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... As of 825 PM Tuesday... 24 Hour TAF Period: VFR conditions will generally continue through the 24 hour TAF period. However, an areas of showers and thunderstorms will likely move into northern and northeastern portions of central NC this evening into early Wednesday morning, before dissipating. KRDU/KRWI stand the best chance of see any convection before this cluster dissipates, though KGSO and KINT could see some storms as well. Sub VFR conditions and gusty winds will be possible with the strongest storms. There is a limited threat of some SCT-BKN stratus and/or patchy fog across the northeast toward daybreak as well. Isolated to scattered showers and storms will be possible Wednesday afternoon/evening, with the best chance across the eastern TAF sites (KRDU/KRWI/KFAY) through 00Z Thursday. Again, sub VFR conditions and gusty winds will be possible with the strongest storms. Outlook: The chances of adverse aviation conditions with scattered, mainly afternoon and evening showers and thunderstorms will increase late week through the weekend as a cold front approaches and then lingers near or just north of the region. && .CLIMATE... Max temperature and high-minimum temperature records... GSO: REC HI DAY MAX YR MIN YR 06/19 100 1944 77 1970 06/20 100 1924 75 2009 06/21 100 1933 75 1924 06/22 100 1914 75 1981 ------------------------------------- RDU: REC HI DAY MAX YR MIN YR 06/19 102 1944 73 2010 06/20 102 1887 77 1924 06/21 101 1933 75 1933 06/22 100 1981 78 1933 ------------------------------------- FAY: REC HI DAY MAX YR MIN YR 06/19 102 1944 77 2017 06/20 102 1970 77 2009 06/21 105 1933 84 1928 06/22 101 1990 84 1928 && .RAH WATCHES/WARNINGS/ADVISORIES... Heat Advisory from 11 AM to 8 PM EDT Wednesday for NCZ041>043- 075>078-085-086-088-089. && $$ SYNOPSIS...BLAES NEAR TERM...Ellis SHORT TERM...BLAES LONG TERM...MWS AVIATION...BSD/BLAES CLIMATE...KCP
Area Forecast Discussion
National Weather Service Blacksburg VA
1123 PM EDT Tue Jun 19 2018 .SYNOPSIS... A weak cold front will drift south into northern portions of the area overnight into early Wednesday before stalling. The front will then oscillate across the region Thursday into Friday before lifting back north as a warm front by the weekend. Another weak cold front should cross into the area from the west later Sunday into Monday. && .NEAR TERM /THROUGH WEDNESDAY/... As of 1123 PM EDT Tuesday...Thunderstorm coverage continues to dissipate, though there remain a few stronger thunderstorms in southern Pittsylvania and Halifax Counties, on the northern end of an outflow boundary that is racing south into the NC Triangle region. Localized downpours may result as showers/storms propagate east. Another area of mostly widely scattered heavier showers is in the Mountain Empire into the mountains of northwest North Carolina, drifting to the east to southeast. Past couple HRRR runs suggest that showers and storms should really begin to move east and/or dissipate by around 1 AM or so. Did opt to leave isolated showers into the overnight hours though into southeast West Virginia - this accounts for ongoing cluster of showers and storms now just west of Charleston WV that may sneak into Summers, Monroe and Greenbrier Counties. Otherwise, no major changes otherwise needed to the going forecast with partly to mostly cloudy skies anticipated overnight and muggy overnight lows in the mid 60s to mid 70s. Previous discussion follows... Convection remains limited across the region this afternoon with best instability just to the north ahead of the sagging cold front. However with coverage increasing to the northwest would expect a few bands/clusters to push south into the I-64 corridor in the next few hours. Still uncertain as to just how far south showers/storms will get until ongoing strong westerly flow relaxes with storms possibly running around the eastern downslope across areas along/east of Highway 29 over the next several hours. Latest short term solutions also show less organization across central and southern sections espcly after loss of heating, although this may be the time for better coverage down along Highway 460 once deeper mixing diminishes. Therefore bumped up pops to a period of likelys northwest per current radar trends, and over the northeast for coverage into the evening. Elsewhere keeping mainly scattered to isolated pops with perhaps the far south remaining dry. Appears showers will slowly fade later this evening but may again redevelop late over the western ridges with low level westerly convergent flow. Otherwise some spotty valley fog/stratus and in spots where showers occurred, with muggy lows only in the 65-75 degree range. Surface front or residual low level outflow may sag into northeast sections early Wednesday before eroding as another impulse rides along the front under lowering heights aloft Wednesday afternoon. This should act to keep the 850 mb boundary to the north with low level focus redeveloping along the surface front across far north or northeast sections Wednesday afternoon. However will still have rather deep westerly flow in place which may again tend to hinder southward extent of any convection until perhaps a more organized band along the front arrives from the northwest per latest Nam/HREF solutions. This supports cutting back pops across all except the north on Wednesday with perhaps best coverage over northeast sections early on, and northwest zones later in the day. Should still be on the hot side despite some 850 mb cooling as westerly flow again enhances compression, while dewpoints linger in the 70s to produce heat indices above 100 again in spots out east. Therefore bumped up highs into the lower/mid 90s south/east, and kept much of the mountains still in the mid/upper 80s with more insolation now expected. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... As of 225 PM EDT Tuesday... Models are similar is flattening the 500MB ridge over the southeast United States and tracking the upper low into the Mid Mississippi Valley which will put the Mid Atlantic region in deep southwest flow by Friday. Best upper diffluence will be over the region on Friday too. The 850MB front advances into West Virginia and Virginia by Friday, far enough south to lower 850MB temperatures in the +12 to +16 range. The slight cooling and more cloud cover will hold maximum temperatures in the 70s and 80s on Thursday and Friday. Front is far enough south that lower Lifted Index values and larger Convective Available Potential Energy will be southwest of a Bluefield to Danville line on Friday. Heavy rain and localized flooding will be a threat on Wednesday night into Friday night due to the possibility of repeated periods of thunderstorms and precipitable water values of 1.5 to just over 2 inches. Confidence average on timing and coverage of rain. Confidence above average on temperatures. && .LONG TERM /SATURDAY THROUGH TUESDAY/... As of 115 PM EDT Tuesday... Models showed decent agreement in the overall synoptic pattern this time range. Surface low pressure crosses from the Ohio Valley into the eastern Great Lake then southeast Canada Saturday and Sunday. Short waves embedded in the broad northeast U.S. trough may trigger some precipitation but the more organized showers and thunderstorms will be Friday night when the upper low lifts into the Great Lakes and Monday with the passage of the next surface cold front. Overall no significant chance in air mass. Temperatures will be near normal to slightly above normal. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... As of 733 PM EDT Tuesday... An elongated outflow boundary (effectively a cool front) extends from just north of Richmond back westward toward the Charleston area. This outflow will likely increase coverage of thunderstorms especially north of route 460 in the next couple hours. Will need to tempo any restrictions but for now have indicated VCTS at Lynchburg and Lewisburg where the greatest short-term threat is. Have tried to follow the latest HRRR guidance in showing this boundary sagging southward and firing showers and embedded thunderstorms south of route 460 (e.g. Roanoke, Blacksburg, Bluefield and Danville), generally between 02-04z. Have indicated VCSH for these TAF sites until a greater convective threat, if any, were to ensue. Confidence in timing and location of thunderstorms along/south of route 460 is low given time of day/likely waning instability and the exact position of the boundary. Outside of showers/thunder, VFR conditions should prevail through at least early-mid evening. One area to watch for possible MVFR type ceilings overnight is across northernmost TAFs (Lynchburg and Lewisburg), with patchy fog in the river valleys and where it rained also a possibility. Winds initially west- northwest 5-10 kts, though as the boundary shifts southward a north wind shift and brief increase toward 8-10 kts/gusts up to 20 kts can be anticipated as it progresses south (especially eastern terminals). However winds should tend light and variable overnight. SCT-BKN VFR mid-level cloud cover should exist early Wednesday. A frontal system will try to sweep to our northeast, bringing a cool front with it that will encourage development of showers and thunderstorms. Still some uncertainty in timing but present indication in terms of convective threat would be after 16z. Storms may become strong with gusty outflow and heavy downpours. Timing will need refinement with later TAF issuances. Overall low to moderate confidence in the 00Z TAF. Lowest confidence in timing showers/storms and related visbys. .Extended Aviation Discussion... Frontal boundary is expected to move south into the Mid-Atlantic and stall for the end of the week. This boundary will then become the focus for repetitive clusters/bands of showers/storms Thursday-Friday with varying VFR to MVFR in clouds/showers with local IFR in areas of heavier rainfall. The front will lift back north Saturday followed by another cold front passing through from the west on Sunday. This should result in improving conditions over the weekend with only periods of sub- VFR likely in more scattered nature showers and storms. Increasing moisture from rainfall will also result in opportunity for late night fog and stratus for much of the period. && .CLIMATE... As of 200 AM EDT Tuesday... Records for June 19/20... Record Highs Record warm Mins June 19 Bluefield WV 91 in 1905 66 in 1920 Danville VA 102 in 1944 70 in 1968 Lynchburg VA 97 in 1944 73 in 1925 Roanoke VA 97 in 1944 73 in 2014 Blacksburg VA 89 in 1984 65 in 2015 June 20 Bluefield WV 91 in 1952 57 in 1920 Danville VA 102 in 1933 65 in 1956 Lynchburg VA 99 in 1964 74 in 1924 Roanoke VA 101 in 1931 76 in 2009 Blacksburg VA 90 in 1994 68 in 2009 && .EQUIPMENT... As of 200 AM EDT Tuesday... The NOAA weather radio transmitter in Hinton, West Virginia that is WXM72 and broadcasting at a frequency of 162.425 MHz is off the air. Parts are on order to repair the transmitter, but there is no known time of restoration. We apologize for any inconvenience. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH NEAR TERM...AL/JH SHORT TERM...AMS LONG TERM...AMS AVIATION...AL/JH CLIMATE...PM EQUIPMENT...
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Wednesday) Issued at 311 PM CDT Tue Jun 19 2018 Ongoing showers and thunderstorms from the morning have continued to move across northeast Kansas this afternoon supported by outflow boundaries and ample buoyancy. With PWATS near two inches and slow storm motion, this convection displayed efficient rain rates with some areas seeing over an inch and a half an hour. Even with the slow movement across northeast Kansas, soils have been so dry that flash flooding was not observed with afternoon storms. Did have to lower some high temperatures today where cloud cover lasted the longest with highs ranging from the mid 80s in far northeast Kansas into the 90s in central Kansas. Some scattered storms have also developed behind this line of storms in north central Kansas and expect these storms to remain scattered and move north into Nebraska this evening. If any of these storms do tap into unmodified air, damaging winds or small hail would be the main hazards (mainly in north central Kansas). For tonight, the inverted trough axis currently located across west central Kansas into north central Kansas will drift into north central Kansas overnight before stalling out tomorrow. Storms will form along this boundary late this afternoon and form into an MCS in western Kansas propagating eastward towards the CWA. Short term guidance has been backing off on the timing for precipitation to enter north central Kansas with most models entering this area after 10pm. Over the past couple runs the HRRR has tended to greatly weaken/dissipate this MCS as it moves into northeast Kansas, but have continued with PoPs through the early morning to account for the NAM which brings precipitation across the entirety of northeast Kansas by early morning. The main hazards with this MCS would be damaging wind gusts, with this threat mainly limited to north central Kansas. Similar to this afternoon, there is also a threat for heavy rainfall leading to localized flash flooding. Have held off on a flood watch for now due to the scattered nature of storms later this afternoon and lack of confidence on how storms will hold together overnight. Wednesday is another one of the days where what happens in the morning will impact what evolves during the rest of the day. The surface boundary Wednesday afternoon looks to be located across the CWA with the warm sector generally in central, east central, and northeast Kansas. Another day of high CAPE low shear exists and if storms can form in the afternoon hours near the boundary, there could be some damaging winds or small hail possible. Temperatures tomorrow do look to be slightly cooler with highs in the low to mid- 80s. .LONG TERM...(Wednesday night through Tuesday) Issued at 311 PM CDT Tue Jun 19 2018 The upper trough Wednesday night deepens as it drifts southeast from eastern Nebraska to eastern Missouri by Thursday night. Any storms Wednesday/Wednesday night will weaken during the overnight hours before more chances for precipitation occur Thursday as the surface low moves east and out of central Plains. With the earlier passage of the front Wednesday night, temperatures Thursday look to be cool topping out in the mid to upper 70s. A brief period of dry weather will occur Friday morning into the afternoon, but from Friday evening through the end of the period, there look to be sporadic chances for precipitation across the CWA. Subtle waves in the flow over central Plains take place over the weekend before a stronger mid-level trough moves towards Kansas Monday night. Although temperatures warm up after Thursday and Friday, they tend to stay near climatology through the weekend only reaching into the upper 80s by Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 632 PM CDT Tue Jun 19 2018 For the 00Z TAFs, expect area that was previously stabilized due to earlier in the day convection to remain that way over all terminals in the near term. Still a range of potential outcomes for storms to slowly creep into the KMHK terminal as the 06Z time frame approaches. Have delayed storms until the 05Z time frame. Timing and coverage of any storms this period is low confidence though, unfortunately, which also leads to only VCTS mention at this time. Updates for the overnight period are likely. For now though, the near term should remain free of immediate aviation hazards. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Heller LONG TERM...Heller AVIATION...Drake