Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/27/19

Area Forecast Discussion
National Weather Service Gaylord MI
946 PM EDT Wed Jun 26 2019 .UPDATE... Issued at 931 PM EDT Wed Jun 26 2019 Quiet summer evening across the northern lakes with mainly clear skies and diminishing winds. Few sensible weather concerns tonight. A weak and moisture starved mid level wave will slide across Lake Superior and into eastern upper later tonight. This will bring a few more clouds to eastern upper and possibly a few sprinkles after midnight. Otherwise it will be mainly clear and dry elsewhere. Temperatures once again on the mild side overnight with relatively high surface dewpoints helping to keep low temperatures in the 50s to around 60 degrees. Also made a tweak to precipitation chances on Thursday as latest high resolution short range modeling brings convective complex into western parts of the area after 00z. Because of this, I removed the POPS from Thursday afternoon. && .NEAR TERM...(Through Tonight) Issued at 325 PM EDT Wed Jun 26 2019 ...An overall quiet and mild night across the Northwoods... High Impact Weather isolated thunderstorm possible across portions of Eastern Upper Michigan thru early evening. Pattern Synopsis/Forecast...All remains quiet across Northern Michigan this afternoon thanks to a drier and more stable airmass in place behind a departing weak cool front. Scattered fair wx CU has developed across much of Northern Lower Michigan...with more robust CU along with a few showers developing across interior sections of Eastern Upper Michigan as expected thanks to lake breeze convergence. Still expect an isold thunderstorm may develop within this region during the rest of the afternoon and early evening hours given around 1000 J/kg of CAPE and some bulk shear present. This may lend to a few higher gusts within any storms that do develop...but certainly do not expect any severe storms. precip development is expected across Northern Lower Michigan thru tonight. Overnight lows will mainly be in the upper 50s and lower 60s. && .SHORT TERM...(Thursday through Saturday) Issued at 325 PM EDT Wed Jun 26 2019 ...Good chance for showers/thunderstorms late Thursday into Friday... High Impact Weather Potential: Marginal risk for severe storms south of M-32 late Thursday. 500mb pattern will be amplifying during the short term. The northern lakes is primarily beneath relatively fast wnw flow aloft, between an upper low over southern Hudson Bay and a large ridge over the s central US. However, an upper low moving into the pacific nw will produce downstream ridging over the northern plains and s central Canada. Heights/temps aloft will be building just to our west, but not here. That will leave us vulnerable to convection, particularly with any passing ripples in the flow. And the most prominent ripple moves thru the region Thu night. Thursday, that next ripple will reach far western Superior by evening. A weak surface reflection will help bring a warm front northward into central lower MI, and perhaps as far as M-72, by early evening. Actual instability over northern MI, north of the warm front, will remain limited until quite late. However, that won`t prevent decaying convection from trying to take a run at us...on multiple occasions. The last, dying gasp of any nocturnal MCS may try to reach nw lower MI toward late morning/midday. Don`t expect it to quite make it here (though recent RAP runs are close), but it will contribute cloud cover. Of greater consequence is deep convection likely to fire in its wake (and just ahead of the ripple) Thursday afternoon in northern WI and western upper MI. The incoming warm front, and peak diurnal heating, will increase the chance for convection to survive the trip across (or, in the case of upper MI, downwind of) Lake MI. There is at least a small chance of an isolated shower/storm popping here late in the day. So chancy pops in order from mid-afternoon on w of M-33 in northern lower MI, as well as in parts of western Chip/Mack Cos. Max temps will be warm, low-mid 880s most common. Thu night, weak surface low pressure (associated the aforementioned ripple) will move east across upper MI. Convective clusters will still try to cross Lake MI into northern lower MI in the evening, especially south of M-32. More widespread precip is likely overnight, again near/s of M-32, as better forcing associated with the incoming wave arrives (and with any earlier convection aiding the moistening process). This doen`t look like a heavy rain event, but QPF amounts of 0.25-0.50 will be seen in some areas, and locally higher amounts are possible. Any svr potential (noting that we are the northern fringe of a marginal risk from SPC) looks to be in a window from 5 pm to midnight. This does not line up with the highest pops for the event (which are overnight). But this is when SbCapes will be at relative maxima (just above 1k j/kg), with 0-6km bulk shear values near 40kt. Convective clusters (originating upstream) riding along the surface warm front and associated instability gradient will have the best chance of produce gusty winds and hail. Min temps upper 50s to mid 60s. Friday into Saturday, somewhat cooler/drier air will make inroads into northern sections behind the departing weak surface low. Much of northern lower MI remains is a relatively warm/moist environment. The Hudson Bay upper low is fighting back the ridging attempting to build east from the plains. A chance for showers/storms will linger across most of northern lower MI Friday. Not expecting much in the way of organization, but with sufficient instability, perhaps some stronger pulse-type storms will be possible in the afternoon/early evening. Pops dwindle to slight chance for Fri night into Saturday, and are suppressed into southern and especially se-ern portions of the forecast area (toward Saginaw Bay). Partly sunny Friday, partly to mostly sunny Saturday. .LONG TERM...(Saturday night through Wednesday) Issued at 325 PM EDT Wed Jun 26 2019 Upstream 500mb ridge axis does fold over into northern MI late in the weekend, only to be quickly suppressed by energy transiting zonal flow along the US/Canada border. Sunday looks most likely dry and continued warm, but after that the pattern becomes more favorable for possible MCS activity. That means a lot of small-chancy pops (for now) beginning Sunday night, with those pops tending to be somewhat higher at night than during the daytime. Temps look to be relatively stable/warm at this juncture, noting that the potential for cooler temps for a day is certainly possible depending on MCS evolution. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 701 PM EDT Wed Jun 26 2019 Surface ridging...strong subsidence and dry air thru the column will maintain solid VFR conditions at all Northern Michigan TAF sites thru Thursday afternoon. No precip is expected through much of Thursday afternoon. Chances of showers/storms will begin to increase Thursday evening and especially Thursday night...just beyond the TAF period. Gusty winds will subside this evening with the loss of daytime heating. After this, winds will generally be less than 10kts through the day on Thursday, varying between southwest and west. && .MARINE... Issued at 325 PM EDT Wed Jun 26 2019 Winds and waves will remain below SCA criteria tonight thru Thursday and even into Friday. Chances of showers and storms will increase on Thursday and Friday along and ahead of an approaching cold front. Locally higher winds and waves are possible in and around any storms that develop. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...JK NEAR TERM...MR SHORT TERM...JZ LONG TERM...JZ AVIATION...JK MARINE...MR
Area Forecast Discussion
National Weather Service Denver/Boulder CO
830 PM MDT Wed Jun 26 2019 .UPDATE... Issued at 808 PM MDT Wed Jun 26 2019 Gusty thunderstorms from earlier this evening have dissipated as they moved out onto the northeast plains. Will cancel the severe thunderstorm watch early. Strongest storms have exited NE CO and the few showers that tried to develop and move off the higher terrain this evening have collapsed. Otherwise, no changes needed to the current forecast. && .SHORT TERM...(This evening through Thursday) Issued at 213 PM MDT Wed Jun 26 2019 Showers and storms are developing over the foothills and adjacent plains as well as over Washington County. Most of the showers will produce very little rainfall but with 60 degree dew point depressions, they will be capable of producing strong wind gusts. Across the northeast corner of the state, RAP analysis indicates close to 3,000 j/kg of Mixed-layer CAPE with lower values farther west. Storms that make it to the northeast corner will be able to tap into the increased instability and may produce severe wind gusts and large hail. These storms will last into the late evening over the northeast corner before exiting the state. Skies will clear out tonight with low temperatures close to normal. On Thursday, downslope winds will increase at the surface with slight warming in the mid levels. This will allow for temperatures to warm well into the 90s across the plains as Denver will see a high near 94. Showers and storms will be very limited tomorrow and very few areas will actually see accumulating precipitation. With the dry air at the surface and dry adiabatic lapse rates, strong and variable wind gusts will be possible in the afternoon again. .LONG TERM...(Thursday night through Wednesday) Issued at 355 PM MDT Wed Jun 26 2019 It`s all upper ridging for the CWA Thursday night through Saturday night. The synoptic scale energy is benign through those periods. The low level pressure and wind fields show a weak pressure gradient over the CWA along with, weak, normal diurnal wind patterns through Saturday night. Moisture stays fairly limited over the CWA Thursday night into Saturday. Both the GFS and ECMWF show an increase in precipitable water values late Saturday and Saturday night. The CAPE isn`t great Thursday night into Saturday, with the best along the eastern border, and lesser values over the high country. Late in the day Saturday, CAPE gets better in the high country. There is a tad of measurable rainfall on the QPF fields Thursday evening. Same for late day Friday and it is just over Park County. With the increased moisture, there is better coverage late day Saturday with fairly decent coverage over all the mountains and foothills with even some 10-20%s over the plains in the evening. For temperatures, Friday`s highs are similar to Thursday; hot and above normals. Saturday`s readings a 1-2 C cooler with the increased moisture. For the later days, Sunday through Wednesday, models keep the upper ridge around all four days, but it is pushed a bit south and southeast of the CWA. There is quite a bit of moisture progged on both the GFS and ECMWF. A cooler airmass moves in on Sunday as well. Temperatures look to be more near seasonal normals all four days. Late day shower and thunderstorm chances look pretty good. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 808 PM MDT Wed Jun 26 2019 The gusty showers from earlier this evening have dissipated and will not expected anymore storm development tonight. Light southwesterly drainage flow can be expected into Thursday morning with VFR conditions persisting through Thursday. Will expect less thunderstorm coverage for Thursday afternoon, however can`t rule out an isolated gusty storm near the terminal between 21z and 01z. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Fredin SHORT TERM...Danielson LONG TERM....RJK AVIATION...Fredin
Area Forecast Discussion
National Weather Service Cheyenne WY
837 PM MDT Wed Jun 26 2019 .UPDATE... Issued at 835 PM MDT Wed Jun 26 2019 Thunderstorms have weakened and/or exited our eastern CWA and cancelled Severe Thunderstorm Watch 450. Isolated showers and thunderstorms are possible along and east of a Chadron to Sidney line through late this evening. UPDATE Issued at 452 PM MDT Wed Jun 26 2019 Updated for Severe Thunderstorm Watch #450 valid until 11 PM MDT for Niobrara/Platte WY, and all of the western NE Panhandle. && .SHORT TERM...(This evening through Thursday) Issued at 143 PM MDT Wed Jun 26 2019 Biggest talking point for the forecast short term today is the severe weather potential and the warm temperatures. The nearly stationary west coast trough is continuing to provide strong southwest flow aloft across the Northern and Central Plains. Subtle ripples in the flow aloft from WV and VIS sat indicate several shortwave disturbances in the height field moving over the mountains. This will help initiate isolated to widely scattered convection amid the southerly and southeasterly low level flow. A well defined surface trough was located along the lee of the laramie range with a stalled front orthogonal to the through through the northern nebraska Panhandle. Higher moisture content with dews in the lower 60s was pooling along the the front across the northern Nebraska Panhandle as evident by manual analysis. This front and immediate proximity will be the focus for a localized greater severe weather threat over the next 2 to 6 hours. Hi-Res guidance is over mixing the boundary layer in proximity to the front reducing forecasted MLCAPES and raising LFC/LCLs. Manual adjustment of latest HRRR soundings results in 2000 to 3000 MLCAPE and 30 to 40 KTS effective shear. LCLs and LFCs under 2 km are also forecast which is very favorable for severe weather. Low level hodographs are supportive of updraft rotation with 100-200 ESRH as analyzed by mesoanalysis. Low level shear is likely enhanced in proximity to the front thanks to a greater easterly component of the low level wind fields. Very steep mid level lapse rates of 8.5 to 9.5 C/km and hail growth cape near 1000 j/kg are present indicating ripe conditions for large to very large hail growth. Several analogs highlight very large hail potential with some of the modified forecast soundings. Current thinking based on observations and CAM guidance is that initial updrafts will evolve near the surface trough in the lee of the laramie range. These updrafts will advect eastward into better moisture and gradually intensify. Isolated supercells with all hazards appear possible in the parameter space. The greatest threat area appears to be along the Nebraska Wyoming South Dakota border where low level shear and CAPE are maximized. Hail to baseball size and a tornado or two are possible if a sustained storm can tap into some of the extra energy. Storms will likely persist into the evening as they move further east into the Panhandle. Tonight high clouds will clear as shortwave ridging develops and moves in. Some fog could develop as the low level wind field dies down and residual moisture sticks around. Temperatures will be very mild overnight with lows in the 50s and 60s. Dry conditions are expected with little lift and most of the moisture pushing off to the east. Thursday will be a very warm day with highs in the 80-s and 90s for most. Ridging aloft should keep shower and thunderstorm chances to a minimum. A few clouds should develop but expect mostly sunny skies and generally warm and pleasant weather for thursday. .LONG TERM...(Thursday night through Wednesday) Issued at 143 PM MDT Wed Jun 26 2019 West coast troughing will continue through the remainder of the week as the trough elongates and ridging builds in fro the south and east. Warm temperatures are expected with the southwest flow and increasing height fields. Friday and Saturday look to continue the recent trend of very warm temperatures. Highs should be near peak summer performance through the first part of the weekend in the 80 to 90 degree range. Overnight lows should be very pleasant in the upper 50s and low to mid 60s. Across the mountains warm temperatures in the 60s and 70s can be expected. A cool front will develop Saturday evening and dive south across the plains. This should bring cooler weather and the chance for showers and thunderstorms from early Sunday through Tuesday. Thunderstorm activity will continue through mid week as the remains of the once stationary west coast trough break down and eject to the east Wednesday and Thursday. Mostly zonal westerly flow should develop behind the passing storm system keeping at least some threat of rain in the forecast fro the time being. Model diverge on the upper air pattern by day 8 but climate trends continue to suggest above average temperatures through the extended. && .AVIATION...(For the 00Z TAFS through 00Z Thursday afternoon) Issued at 535 PM MDT Wed Jun 26 2019 VFR will prevail through Thursday. A few showers are possible near KCYS and KLAR thru 02Z. VCTS for thunderstorms for the NE Panhandle terminals thru 04Z. Aviation hazards with thunderstorms will be brief MVFR VIS, erratic/gusty winds and hail. && .FIRE WEATHER... Issued at 143 PM MDT Wed Jun 26 2019 Marginal elevated fire weather condiitons will be possible across the interior valleys over the next few days. Warm temperatures and low humidity will bring atmospheric conditions to elevated but not critical values. Area fuels remain unreceptive and little threat is expected. && .HYDROLOGY... Issued at 143 PM MDT Wed Jun 26 2019 Overall trend of elevated but slowly decreasing flows will continue for the next few days as snowmelt slowly continues to contribute to baseflow. Canceled the flood warnings and will maintain an RVS for now as insurance given that flows will remain just below flood stage. Dont expect much in the way of precip for a few days but next weekend could trigger more hydro concerns. ...PREVIOUS DISCUSSION... Trends on headwaters gauges coming out of the Snowy and Sierra Madre Ranges have shown river levels coming down slowly. Still need to wait to see effects of increased snowmelt over the next several days before we can say for certain that flooding threat is over. Warmer temperatures over the next several days will let us know that impact. Rain still forecast for late weekend into next week and a rain on snow event is still not out of the question. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ UPDATE...MAJ SHORT TERM...Lyons LONG TERM...Lyons AVIATION...MAJ FIRE WEATHER...Lyons HYDROLOGY...Lyons/GCC
Area Forecast Discussion
National Weather Service Indianapolis IN
1152 PM EDT Wed Jun 26 2019 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 232 PM EDT Wed Jun 26 2019 High pressure in place over southern Appalachia will provide warm...humid...seasonable summer weather for Central Indiana for the rest of the work week. Most locations will stay dry through Friday...however a few very isolated showers and storms cannot be ruled out due to the warm and humid air mass in place. This weather pattern looks to continue into the weekend. A more organized system will arrive early next work week, bringing better chances for rain. && .NEAR TERM /Tonight/... Issued at 232 PM EDT Wed Jun 26 2019 Surface analysis this afternoon shows high pressure in place from West Virginia to Georgia. Warm and humid southwest flow was in place across Indiana. Dew points were in the mid to upper 60s. GOES16 shows a field of CU across the SW parts of the forecast area. Satellite shows an MCV over SW MO...producing a few showers. meanwhile aloft...ridging was in place across the plains states. The ridge is expected to strengthen overnight and relatively weak flow will remain in place aloft. The models suggest that the MCV will make minimal progress SE...while a weak short wave arrives from the northwest. Forecast soundings show steep lapse rates with attainable convective temperatures for a few hours. However deep moisture and organized forcing does not appear available. HRRR shows a band of showers moving into the SW tonight...but that seems associated with MCV which and it will be unlikely that it makes that quickly of an approach. Thus will keep some very minimal chances for precip tonight for the renegade shower...but most areas will look to remain dry. Confidence for rain is low. Given the warm and humid air pass in place...will trend temps at or above the NBM blends. && .SHORT TERM /Thursday through Saturday/... Issued at 232 PM EDT Wed Jun 26 2019 Models suggest that strong ridging will build across the Mississippi valley through Saturday...allowing weak NW flow to persist aloft over Indiana. Within the flow aloft the models show a few weak...unorganized short waves passing toward Indiana. Time heights show manly only lower level through the period with subsidence in place on thursday through late Friday Night. Forecast soundings again show limited deep moisture and the primary form of available lift appears to be summertime daily heating. Thus again...confidence for organized showers during this time is low. Again...most areas should remain dry...but an isolated diurnal shower or storm cannot be ruled out. Will probably use very low pops. Given the warm air mass in place...will trend highs and lows at or above the NBM blends. && .LONG TERM /Saturday night through Wednesday/... Issued at 300 PM EDT Wed Jun 26 2019 Models and ensembles generally keep the forecast area under of stagnant ridge of high pressure, typical for this time of year. This supports mainly dry weather with above normal temperatures and high humidity. However, there is enough dip in the westerlies to support chance PoPs next Tuesday and Wednesday per the blend. && .AVIATION /Discussion for the 27/06Z TAF Issuance/... Issued at 1150 PM EDT Wed Jun 26 2019 VFR conditions will continue to prevail for the duration of the TAF period with high pressure in place. Meanwhile, winds will be light and variable. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...Puma NEAR TERM...Puma SHORT TERM...Puma LONG TERM....MK AVIATION...TDUD
Area Forecast Discussion
National Weather Service Louisville KY
957 PM EDT Wed Jun 26 2019 .Forecast Update... Issued at 956 PM EDT Wed June 26 2019 Scattered to numerous showers and storms are persisting along and west of I-65 this evening. The main concerns at this hour will be lightning, briefly heavy rainfall, and gusty winds to 40 mph. Some small hail has been observed at times, but will be really isolated in nature from this point forward. Still expect storms to take a downward trend in coverage/intensity as we approach Midnight, and reflect this in the Pops holding west of Louisville. Will continue to monitor. Previous Update... Issued at 752 PM EDT Wed Jun 26 2019 Scattered to numerous showers and storms are ongoing over the MO Bootheel, southern IL, and western KY ahead of a remnant MCV. Some of these clusters may survive into our western around 02-03z. Of more immediate concern is a secondary batch of showers and storms across west central KY along our mutual border with PAH. These storms are posing a localized downburst wind threat in an environment characterized by 2500-3500 J/KG of SB CAPE and DCAPE values around 1400-1500 J/KG. Seeing some nice t-storm outflow from storms very close to HPX radar and have noted that some winds close to the severe threshold will be possible with any stronger core that gets toward 40 K feet. Suppose that isolated instances of large hail are also possible, but mainly concerned about wind, lightning, and localized heavy rainfall. Deep layer shear is not very strong and slow storm movement combined with any repeated showers/storms could lead to a localized Flash Flood threat. Convective activity is expected to diminish as we near the Midnight hour. && .Short Term...(This evening through Thursday) Issued at 300 PM EDT Wed Jun 26 2019 Afternoon satellite imagery and observations reveal mostly sunny skies across the region. A diurnal Cu field was observed and temperatures ranged from the lower-mid 80s over the eastern half of the forecast area to the mid-upper 80s out across the western areas. The Louisville heat island will likely hit 90 before peak heating wanes. Elsewhere, highs in the mid-upper 80s are expected before temps drop back into the upper 70s to the lower 80s this evening. For this evening and overnight, will be watching a well defined MCV over Missouri. Convection is firing on the eastern edge of this feature across MO. This activity will spread into western KY and southern IL this evening. Just how far east this convection will get is the main forecast challenge for this evening. While we do have 1500-2000 J/Kg of CAPE available, we really do not have much in the way of shear over the region. Convection will also be moving into the region as the sun goes down which will lead to a decrease in overall instability. Mesoscale models suggest that convection may get as far east as the I-65 corridor. So, will plan on just keeping some 20-30% coverage over our western counties, but will not take PoP chances east of the I-65 corridor. Any convection remaining would likely die out in the 10-11 PM EDT time frame with the rest of the night remaining dry. Overnight lows look to dip into the upper 60s to the lower 70s. For Thursday, much of the day looks to remain dry with highs in the mid-upper 80s once again. Will have to watch how Wednesday night`s convection evolves and whether some sort of remnant outflow boundary hangs over the region. Last few runs of the HRRR suggest that a left over boundary could serve as a focus for convection in between I-65 and I-75 tomorrow. Current forecast plans are to leave PoPs less than 15% now and evaluate later data tonight and tomorrow morning. Overall environment would support some storms, but coverage would look to be rather limited. .Long Term...(Thursday night through Wednesday) Updated at 250 PM EDT Wed Jun 26 2019 Ridging across the central and southern CONUS continues into the long term, which will continue the warm, dry weather into the weekend. Expect light winds mainly out of the southwest through the weekend with temperatures slightly above climatological norms. Chance of isolated, diurnal showers/storms increases Saturday and Sunday, but still expect a dry forecast for most. At the start of the work week, a series of strong low pressure systems propagating through the longwave pattern to our north begin to deamplify the central CONUS ridge, while return flow brings precipitable water values back into the 1.50 to 2.00 inch range over the Ohio Valley. These two factors will lend to better chances of diurnally induced showers and thunderstorms across the CWA. Model variance continues through the first half of next week; however, they do agree on a possible shortwave bringing more organized convection to the area on Wednesday. Max temperatures through the first half of next week will continue to reach into the low 90s with dewpoints in the upper 60s to lower 70s. && .Aviation...(00Z TAF Issuance) Updated at 739 PM EDT Wed Jun 26 2019 SDF/LEX will stay VFR with mostly clear skies for the remainder of the evening and much of the overnight. Toward dawn, LEX may develop some MVFR fog. Some upper sky cover from T-storms to the west will likely be noted the deeper into the evening we get. The main concern at BWG/HNB will be the chance for scattered thunderstorms through the late evening hours to just past Midnight. Mentioned some VC and TEMPO groups to account for this threat, otherwise expect to stay VFR outside of any convection this evening. As we near dawn on Thursday, some MVFR fog is also possible at BWG and possibly HNB if it can clear out. After any morning fog on Thursday, expect VFR with a light S or SW wind. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...BJS Short Term...MJ Long Term....CG Aviation...BJS
Updated for 00Z Aviation Forecast Discussion below.

PREV DISCUSSION... /issued 355 PM CDT Wed Jun 26 2019/ DISCUSSION... Radar and satellite imagery currently shows multi-cellular thunderstorms over eastern MO and northern AR moving east- southeast. A trough is shown on analysis charts over southeast MO which is helping trigger thunderstorm development. The storms will likely hold together as they head towards the northern portions of our CWA. MLCAPE is currently 3,500 J/kg or higher in some spots with MUCAPE as high as 6,000 J/kg, so there is plenty of instability to work with. Most of the storms aren`t expected to reach severe limits due to low bulk shear values with most areas seeing approximately 10kts of sfc-6km shear. That said, a few isolated strong-to-severe storms can`t be ruled out given the setup and high instability. If storms start to train, flooding will also be a concern with corfidi downshear and upshear values of 5-15kts shown on short term models. The typical Summer-like weather will continue through the next week with a more meridional longwave pattern expected as we progress through the coming days. A ridge will build over the eastern portion of CONUS, providing a consistent southerly flow over the Mid-South. The theme for the next week will be rinse-and- repeat. Diurnal showers and storms developing during daytime heating is expected. Isolated-to-scattered convective thunderstorms will develop every afternoon for the next week with tomorrow being the best shot at seeing thunderstorms. Temperatures will be relatively consistent with a persistent ridge situated over eastern CONUS with no strong disturbances or fronts expected to move through the area. Highs will mainly be in the low 90s with lows dropping down into the low 70s most nights. Winds will remain light from the south 5-10mph. Looking further into the long range, it looks like the ridge will finally break down by the end of next week as we see more of a zonal flow over CONUS. Models show slightly cooler temperatures arriving by the end of next week as well. KRF && .AVIATION... 00Z TAFs A compact upper low over southeast MO will lift east into southern IL during the late evening and overnight. TSRA around the southern periphery of this low affected JBR, the MO bootheel and northwest TN prior to discussion time. This TSRA generated a low level cold pool outflow that will drop to MEM and MKL early to mid evening. SHRA/TSRA will likely occur behind the outflow in the interim. Surface instability will weaken by the time the convection reaches the MEM vicinity, likely limiting thunder potential - but it will be a close call. Mainly followed the more consistent HRRR model. Second wave will drop southeast overnight, behind the main upper low. All short range guidance suggest at least scattered SHRA/TSRA dropping south through the JBR/MEM and possibly MKL terminals overnight. Models differ on timing and location. But the agreement on occurrence warranted an inclusion of TSRA overnight, given the strength of the remnant upper wave and moist unstable air off feeding into the region around FL020. As with all elevated nighttime SHRA/TSRA, confidence in timing and placement is a bit limited. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Marquette MI
631 PM EDT Wed Jun 26 2019 .SHORT TERM...(This evening through Thursday) Issued at 415 PM EDT WED JUN 26 2019 Water vapor imagery and RAP analysis show mid-level lows centered over James Bay and off the OR coast. Btwn these features, mid-level ridge is beginning to build over the central CONUS. In the resulting wnw flow over the northern Great Lakes, it`s been a warm, mostly sunny day today across the fcst area. Temps have risen into the upper 70s and lower 80s with local cooling along the Great Lakes. Sct cu has developed, and sct shra have recently developed over far eastern Upper MI along lake breeze boundaries from around Manistique to KCIU and Drummond Island. Under cooler air aloft to the n and in the track of subtle shortwaves, some shra/tsra developing nw of Lake Superior may reach Isle Royale over the next several hrs before dissipating. None of this activity will survive across the lake to affect any other portion of Upper MI. Otherwise, expect a quiet night tonight with no apparent shortwaves approaching the area and with theta-e ridging and low-level jet well off to the w and sw. Min temps will mostly be in the 50s. Across the w and n closer to Lake Superior where a little more wind will be stirring, temps should stay above 60F. On Thu, attention turns to the potential of convection. In the sw flow btwn the mid-level low offshore of the Pacific NW and the building central CONUS ridge, a shortwave is fcst to emerge tonight over the northern Rockies, then round the ridge, tracking toward the western Great Lakes late in the day. There is quite a range of solutions on how convection will evolve in association with this wave, from driving squarely toward Upper MI late in the day to the convection tending to shift ese as it approaches. Difficult to say how the convection will evolve, but seems unlikely that significant convection will drive directly toward Upper MI. Probably the more likely scenario is that the main area of more significant convection tied to the wave will ride along the stronger instability gradient toward northern WI, and perhaps with time, peel a bit s into the greater instability to the s. Fcst will follow this idea thru Thu aftn. Otherwise, building of instability may lead to isold/sct convection over the w half mid and late aftn, excluding the Keweenaw due to stabilizing easterly winds. Highs will mostly be in the low/mid 80s with local cooling along the Lakes. .LONG TERM...(Thursday night through Wednesday) Issued at 500 PM EDT WED JUN 26 2019 To start off this forecast period, models are struggling to come into decent agreement about what`s going to happen tomorrow night. Both the NAM and CMC (regional/hi-res), with the GFS coming into agreement, have a MCS-looking feature scooting right across the U.P. (from west to east). There is still quite a bit of uncertainty, given the lack of run-to-run consistency, but this northward trend is something worth keeping an eye on as this timeframe inches closer and models continue to come into better agreement. Stay tuned. With Upper Michigan entrenched in the summertime pattern, regularly- mentioned PoPs continues throughout much of the long-term as mesoscale features play more of a prominent role in driving the chances. Temperatures will continue with the trend running slightly to moderately above normal into next week, with the warmest day looking to occur on Saturday as UL ridging allows for ample WAA. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 630 PM EDT WED JUN 26 2019 VFR conditions will continue at KIWD/KCMX/KSAW. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 415 PM EDT WED JUN 26 2019 Across Lake Superior, ongoing sw winds of generally 10-20kt at buoy heights and 25-30kt at high obs platforms will diminish some tonight, leading to a day of lighter winds generally under 15kt on Thu. Winds will then generally be under 15kt thru the weekend under a weak pres gradient. Should any showers and thunderstorms move across the lake over the next several days, dense fog will likely develop. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...lg AVIATION...07 MARINE...Rolfson