Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/31/19


Area Forecast Discussion
National Weather Service La Crosse WI
1020 PM CDT Thu May 30 2019 .SHORT TERM...(Tonight) Issued at 300 PM CDT Thu May 30 2019 GOES water vapor and RAP 500mb analysis showing a mid-level low tracking eastward across IA into IL. Frontogenetic forcing/axis of dilatation associated with this low was producing a few showers mainly south of I-90. Meanwhile, warm air advection ahead of another wave of low pressure moving through southern Canada was producing some mid-level cloudiness but nothing showing up on radar so far. Another satellite highlight is smoke aloft from Alberta Canada wildfires working south through the region. This was producing a thin milky overcast. Otherwise, temperatures across the forecast area were in the low/mid 70s. For tonight, that closed mid-level low to our south will open into a trough and progress away from the area, taking any remaining showers/ clouds with it. Meanwhile that wave over southern Canada will progress southeastward will dampen out as mid-level ridging amplifies eastward into our region. Could see a few showers brushing north central WI this evening, but mid-level ridge and surface warm air advection will push shower/isolated thunder threat more into Up per Michigan/far northeast WI. Overnight lows are expected to bottom out in the 50s under partly cloudy skies. .LONG TERM...(Friday through Thursday) Issued at 300 PM CDT Thu May 30 2019 The near term focus will be on Friday afternoon into the evening. The upper level flow over the Upper Midwest will be northwest which will allow a short wave trough rotating around the two Canadian upper level lows to move across the region Friday night through Saturday morning. This wave does look to come through with a positive tilt which will lead to only some weak pv advection in the 500-300 mb layer. In the low levels, a cold front will sink slowly south across the region with the short wave trough. The moisture transport will start to increase Friday afternoon ahead of the short wave trough and be the strongest Friday evening. However, the axis of transport looks to be rough parallel to the front instead of into it which will reduce the degree of convergence occurring along the front. The forcing from the short wave trough will be enhanced by a rather healthy frontogenesis band in the 1000-850 mb layer along the front. This frontogenesis will be much weaker but some suggestions it could extend through the 850-500 mb layer as well. Expecting there to be enough overall forcing to generate some showers and storms along the front, especially during the evening when the moisture transport is the strongest. There will be some severe potential with these storms during the afternoon and evening as well. ML CAPES look to build to about 1500 J/Kg ahead of the front as dew points reach the upper 50s with air temperatures in the middle to upper 80s. Shear in the vicinity of the front looks to be between 30 and 40 knots and mainly in the 0-3 km layer. Forecast soundings for KMDZ suggest a good inverted-v profile below the cloud base to enhance the wind potential. Wet bulb zero heights would also suggest the potential for some hail along with the wind threat. With the relatively slow movement of the front, the chance for the showers and storms will continue into Saturday morning for most of the area and then across the southeast for Saturday afternoon. After that, a large area of high pressure looks to build in and provide a couple of dry days for Sunday and Monday. The next chance for some rain then looks to arrive for Tuesday and Wednesday. The upper level ridge that builds in with the area of high pressure at the surface, looks to get flattened by a short wave trough that gets ejected out of the upper level low over the Desert Southwest. Right now, there looks to be decent agreement between the 30.12Z ECMWF and GFS with this wave looking to have a positive tilt as it pushes a cold front into and through the area. The forcing looks to be the best Tuesday night which is when the highest rain chances will be with this system. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1020 PM CDT Thu May 30 2019 Cigs: milky skies thanks to smoke coming down from Canada will likely linger across the region through tomorrow. Mostly mid level clouds then look to move in from the north late Fri night, associated with a cold front. Cigs might not make it in until Sat morning - with models favor keeping it VFR. WX/vsby: Next decent shot for shra/ts may hold off until Sat with the southward dropping cold front. Winds: mostly light/vrb tonight, increase a bit and more west/southwest Fri. Could see some afternoon gustiness with deep mixing upwards of 7 kft. That said, winds only in the low 20kts expected at that level, so gustiness will be held in check a bit. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...DAS LONG TERM...04 AVIATION...Rieck
Area Forecast Discussion
National Weather Service Bismarck ND
921 PM CDT Thu May 30 2019 .UPDATE... Issued at 920 PM CDT Thu May 30 2019 Current forecast trending ok with mainly clear skies this evening. Winds are diminishing north. No changes. UPDATE Issued at 555 PM CDT Thu May 30 2019 Early this evening skies were generally clear across the region with a few mid clouds scattered across the east and northwest. Gusty southwest winds up to 35 mph have been seen across the northwest and north as mixing maxed out late this afternoon, but winds will diminish quickly after 7 PM. Otherwise a dry atmosphere will continue to inhibit precipitation over the next 24 hours. A cold front will move south through the region late tonight across the north, and through the south by Friday morning. There is some uncertainty as to the chances for showers, as the front seems to be outpacing its support for convection in terms of shear and CAPE. Only the far south is expected to see any showers Friday. Current forecast looks ok with only changes made to the winds north, raising them a about 5 to 10 mph for the early evening hours. && .SHORT TERM...(This evening through Friday) Issued at 224 PM CDT Thu May 30 2019 A cold front will push from north to south through North Dakota tomorrow, bringing cooler temperatures and a chance for afternoon and evening thunderstorms across far southern North Dakota. The latest iteration of the NBM suggests a somewhat mild night tonight with lows generally in the mid 50s to around 60 degrees. Skies will remain clear, aside from some lingering upper level smoke from wildfires burning in Canada. The latest iteration of the HRRR Smoke model depicts a brief break in the smoke late tonight, before another round of upper level smoke potentially returns to the area from the northwest during the day tomorrow. The 12z GFS/NAM/EURO agree well on the timing of a cold front for tomorrow, which pushes through northern North Dakota during the early morning hours and through central North Dakota during the late morning and early afternoon. By 4 PM CDT, the front is already draped across the southern border. This will lead to cooler temperatures for tomorrow, with the NBM suggesting highs mainly in the 70s. This cold front will also be the focus for scattered thunderstorms across far southern North Dakota, likely initiating around 4 PM CDT and pushing into South Dakota shortly thereafter. The latest CAM model guidance is now keeping nearly all of the convection in South Dakota, with little to no precipitation in our area. With that being said, previous runs had scattered thunderstorms across southern North Dakota between 4 and 7 PM CDT. Whether storms end up affecting our area or not, severe weather is not expected due to a lack of shear and a linear storm mode. .LONG TERM...(Friday night through Thursday) Issued at 224 PM CDT Thu May 30 2019 Dry and pleasant this weekend before warmer temperatures and chances for thunderstorms return on Monday and Tuesday. A surface high looks to dominate the weather pattern across North Dakota on Saturday with northwest flow aloft. This should lead to a quiet, sunny day with highs in the 70s. It is unclear at this time is upper level smoke will impact the area on Saturday and lead to hazy skies. Warmer temperatures begin spreading into western North Dakota on Sunday as an upper level ridge begins building in from the west and a surface warm front approaches. This warm front is set to move through the area Sunday night, with little to no precipitation expected as the front will be moving through a very dry and somewhat stable air mass. This will put western North Dakota and much of central North Dakota in a warm sector on Monday, with widespread highs in the upper 80s and around 90 degrees. The 12z GFS shows very high surface based CAPE values within the warm sector by 7 PM CDT Monday, with values exceeding 4000 J/kg across portions of western and central North Dakota. With that being said, shear looks lacking with only 15 to 25 kts of 0 to 6 km bulk shear. A cold front will be the focus for convective initiation somewhere near the Montana/North Dakota border during the late afternoon, spreading eastward through western North Dakota through the evening hours. Although a discrete storm mode is favored within a highly unstable environment, there is still much uncertainty regarding the potential for severe weather given the lack of shear and uncertainties with dew point temperatures. The warm sector will continue moving eastward on Tuesday, with the NBM suggesting highs in the mid to upper 80s across central North Dakota with slightly cooler temperatures to the west. With the cold front located across eastern North Dakota by Tuesday afternoon, most of Tuesday`s convection appears to be limited to eastern North Dakota at this time... with western and central North Dakota staying dry. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 555 PM CDT Thu May 30 2019 A cold front across southern Saskatchewan and Manitoba is forecast to move south into and through North Dakota tonight and early Friday morning. We expect the front to be be mainly dry, with a scattered showers possible south of KDIK-KBIS-KJMS Friday afternoon. VFR all TAF sites. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...TK LONG TERM...TK AVIATION...WAA
Area Forecast Discussion
National Weather Service Buffalo NY
1028 PM EDT Thu May 30 2019 .SYNOPSIS... A weak cold front will move across the region overnight with patchy fog but otherwise mainly dry conditions. High pressure will build across the region on Friday with clearing skies and temperatures rising to within a few degrees of normal. Another cold front will drop across the region Saturday, spreading additional showers and thunderstorms across the region. && .NEAR TERM /THROUGH FRIDAY/... A cold front near the north shores of Lake Ontario will push southward overnight, and across the region through daybreak. This will be a mainly dry frontal passage, with the best chance of a shower across the North Country, but even there any activity should be scattered in nature with instability and moisture limited. While this front will likely clear out low level moisture in its wake east of Lake Ontario, lots of low level moisture will remain south of Lake Ontario. There is already a fog bank across eastern portions of Lake Erie, with this extending northeast of the lake into the Buffalo metro area. The HRRR provides fair guidance on the progression of this area of fog. In addition to this, fog is also likely to develop across the western Southern Tier like it has the past two nights. Behind the front, a narrow area of high pressure will pass across our region tomorrow. This will suppress precipitation activity...with our area mostly to partly sunny through the day. Temperatures tomorrow will rise to within a few degrees of normal...with highs in the mid 60s to lower 70s. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... The closed low over northern Quebec will remain in place during this period, providing the focus for continued active weather to trek through and around the base of its associated trough. After a mostly dry Friday night, a weak area of low pressure and frontal system will cross the region on Saturday. This system will bring the best chances for showers from the morning through the afternoon across the area. Saturday night will provide somewhat of a break from the rain showers before the next chance of showers/rain on Sunday. Some lingering showers may still persist Saturday night, with primarily low chance POPs across the area. A deepening trough will track around the closed low from the Northern Great Lakes Saturday night to the Central Great Lakes on Sunday night. At the same time a potent area of PV will track southeast on the western portion of the trough toward the trough axis. As this PV anomaly tracks toward and begins to round the base of the trough through Monday morning an area of low pressure centered over the Eastern Great Lakes on Sunday afternoon will begin to strengthen. This area of low pressure will trek northeast toward New England as it strengthens. Increased rain coverage will begin on Sunday morning as the area of low pressure strengthens over western and north central NY. Likely POPs will cover most of the area during the morning and shift east with the area of low pressure through the day. Chance POPs will continue through the night on Sunday. Winds will start to increase late Sunday through at least Monday with an increasing pressure gradient that will be over the region as an area of high pressure from the Central Plains approaches and the area of low pressure shifts northeast. Temperatures on Saturday will be in the upper 60s to near 70 for most of the area. Sundays high temperatures will be slightly cooler in the mid 60s and occur ahead of the passing cold front and area of low pressure. Timing of the system passing will be the determining factor for the temperatures on Sunday. Cold air advection behind the low pressure system on Sunday will drop 850Ts to the low single digits by late Sunday evening. Low temperatures Friday and Saturday night will be in the upper 40s to low 50s. On Sunday night with cold air advection behind the departing low, temperatures will cool to the mid 40s for most areas. && .LONG TERM /MONDAY THROUGH THURSDAY/... A ridge in the west and trough in the east will promote below normal temperatures early next week. Forecast guidance is in agreement that a closed 500hPa low will track from the Northeast to the Canadian Maritimes Monday-Tuesday night. Showers will be possible as this feature exits to the northeast Monday-Monday night. Surface high pressure will track across the Central U.S. and into the Mid- Atlantic region by Tuesday night. This will lead to mainly dry conditions Tuesday-Tuesday night. High pressure then moves off the east coast mid-week and a southerly flow will allow temperatures to average near or slightly above normal. The chance for showers increases Wednesday-Thursday as a cold front tracks across the Great Lakes basin. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... A weak cold front will slowly push southward across the region overnight. There may be a few showers east of Lake Ontario, but otherwise the front will be mainly dry. The main challenge is the potential for fog and associated low ceilings tonight. The primary concern is at KBUF where a fog bank has spread northeast of Lake Erie. IFR or lower conditions are expected to last much of the night at KBUF and may move into KIAG at times. There is potential for dense fog, however a modest 5-10 knot flow may be enough to prevent this however forecast confidence is low. Elsewhere, fog also appears likely at KJHW where fog has developed the past two nights. Fog cannot be ruled out elsewhere, but the chances are less with slightly drier and a less lake influence flow at KART/KROC. Surface high pressure will push towards our region Friday, with light winds and flight conditions improving back to VFR. Outlook... Saturday...VFR with scattered showers/thunderstorms and attendant MVFR. Sunday...VFR/MVFR with showers likely. Monday...MVFR. A chance of showers to the east. Tuesday...VFR. && .MARINE... A light pressure gradient will persist across the Eastern Great Lakes tonight and Friday. A weak cold front will drop across Lake Ontario overnight. Winds and waves will remain light through much of the weekend with the lack of any strong low/high pressure systems. Later Sunday an area of low pressure tracking across the Eastern Great Lakes may deepen...such that strong northwesterly winds become possible late Sunday night and through Monday night. && .TIDES/COASTAL FLOODING... Low pressure will pass to our north Sunday night and this will result in an increase in northwesterly winds late Sunday night which will continue through Monday night before winds shift to the west and diminish on Tuesday. Stronger winds will build waves on Lake Ontario, and this has the potential to cause lakeshore flooding late Sunday night through Tuesday. There is still uncertainty since wave action depends on exactly how strong the winds turn out to be. This risk was added to the Hazardous Weather Outlook. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ SYNOPSIS...Apffel/Thomas NEAR TERM...Thomas SHORT TERM...Apffel/SW LONG TERM...RSH AVIATION...Apffel/Thomas MARINE...Apffel/Thomas TIDES/COASTAL FLOODING...Apffel
Area Forecast Discussion
National Weather Service Grand Forks ND
928 PM CDT Thu May 30 2019 .UPDATE... Issued at 924 PM CDT Thu May 30 2019 Breezy winds have settled down and generally light to around 10 mph. CU adjacent to valley is shifting east and eroding with loss of solar. Temp curve on track and no changes expected to ongoing forecast. Tomorrow a cold front drops in from the north and will sink due south, leaving southern valley mid-afternoon. With boundary just south of CWA near peak heating, threat for convection remains low but a storm or two cannot be ruled out. && .SHORT TERM...(This evening through Friday) Issued at 349 PM CDT Thu May 30 2019 Early this afternoon, surface observations indicate an area of surface winds converging in north central MN between Bemidji, Grand Rapids, and Wadena. Underneath wildfire smoke streaming overhead, there appears to be cumulus development across north central MN, indicating cap weakening in this region. Despite limited low level moisture with dew points in the upper 40s to lower 50s and 5-7 kft LCLs, steep low level lapse rates, modest mid level lapse rates, and a narrow axis of 30-40 kts of effective bulk shear suggest potential for development of isolated strong to severe thunderstorms late this afternoon and early this evening. However, the window for severe weather is quite short as storms would quickly progress southward into the DLH/MPX areas of central MN due to northerly cloud mean layer winds. This potential for severe weather occurs ahead of a weak frontal boundary extending from approximately Bemidji to Fergus Falls and back west toward Britton SD. Can`t rule out storms developing further southwest in unstable air in Ottertail and Grant counties and into northeast SD, but chances for severe weather are much lower in this region due to weaker shear. Otherwise the Northern Plains remains under the influence of northwest flow aloft, and smoke from the Canadian wildfires is expected to continue to advect into the region. The latest HRRR and Canadian smoke models suggest a period of lower concentrations tonight, indicating some improvement in air quality before another push of higher concentrations is likely for Friday afternoon and night. Expect overnight temperatures to drop into the 50s to lower 60s as another surface low propagates from southwest MB toward the MN arrowhead. A west-east frontal boundary progresses southward through the region during the day Friday, advecting dry and cooler air into the region behind it. Locations north of this boundary can expect to see highs only reach the upper 60s to near 80 degrees on Friday. South of this front in the southern valley and much of MN lakes country, expect a warm day with highs in the mid 80s, as this portion of the region remains in the warm sector of that sfc low with anomalously warm 850mb temperatures. Along and ahead of this boundary (southern valley and parts of MN lakes country), shower and storm chances develop Friday afternoon and evening. With low to moderate instability and 0-6km shear in the 30s, cannot rule out a few stronger thunderstorms Friday afternoon and evening along and south of this boundary. .LONG TERM...(Friday night through Thursday) Issued at 349 PM CDT Thu May 30 2019 Friday night through Sun... The passage of a cold front on Fri will lead to lower temps during the day on Sat. A nearly imperceptible boundary moving down during the afternoon should only serve to reinforce the cooler high pressure; no sensible weather would be expected. High temps are currently pegged to be from the mid 60s to near 70 degrees. The coolest night in a while will follow, with high pressure and light winds allowing the mercury to dip toward 40 degrees along and north of Highway 2. Sun will be dry as well, adding a few degrees to the high temps. Mon through Thu... Guidance has been coming into better agreement for the early to middle part of next week. Look for zonal flow with most of the energy and forcing remaining north of the border. Chances for RW/TRW increase over our area Mon night into Tue along and ahead of the next frontal boundary approaching later Tue. Drier weather will return for mid week. It will be a bit warmer Tue and Wed with highs closer to 80. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 649 PM CDT Thu May 30 2019 CAVOC...expect winds to back off to west as gustiness subsides this evening...then an abrupt shift to northerly flow on Friday as a cold front sinks through the valley during the day. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...PJS SHORT TERM...BP LONG TERM...WJB AVIATION...Speicher
Area Forecast Discussion
National Weather Service Hastings NE
632 PM CDT Thu May 30 2019 .SHORT TERM...(This evening through Friday) Issued at 242 PM CDT Thu May 30 2019 Primary forecast concern for late afternoon into Friday is the small chance for a few pop up showers and perhaps even a thunderstorm or two late this afternoon into the evening. Current satellite and 12Z upper air data showing a wavy pattern across N America with a deep low near the southeast part of Hudson`s Bay, along with lows over southern IA/northern MO and northern CA. Ridging has built in from eastern MT south across the Rockies, although a weak low was noted in water vapor imagery near the WY/CO border. At the surface, we have low pressure to the east in IA with ridging over the Rockies putting our CWA in W to NW flow. Most of the clouds during the morning hours and we had mainly clear skies until cumulus clouds popped by mid afternoon. Regarding precip chances into this evening...we are still being influenced by the upper low just to our east as we remain in cyclonic flow aloft. Temps cool in mid levels as we sit around 1-3C at 700 mb. Adequate low level moisture also in place. Thus the mention of afternoon cumulus formation earlier. As to whether or not we will see any rain, spotty showers still seem possible and even a thunderstorm or two cannot be ruled out as progged ml CAPE to be in the 500-1000 J/kg by mid afternoon. Severe storms not a concern as deep layer shear is negligible. As far as the models go, the latest operations runs of the NAM, GFS and RAP all dry the next 12 hours, while the CAMs do depict at least spotty activity starting around 21 or 22Z. NAM nest still showing this although the 12Z run not quite as robust as the 06Z run. It does continue to show the coverage over much of the CWA albeit sparse at best. Different versions of the HRRR favoring the western CWA although overall coverage is pretty small. Anything that does form should die out around sunset. Will most likely leave POPs at 15 percent and decide at the last minute whether or not to include thunder. The rest of the night should be quiet as the ridge to the west begins to build in. With upper ridging and flow more southwesterly on Friday, temps should be 4-8 degrees higher than today. The current wave to our east should continue moving away from us and with no other waves of note, expecting mainly dry conditons. .LONG TERM...(Friday night through Thursday) Issued at 242 PM CDT Thu May 30 2019 For the early part of the extended period, we should be in northwest flow with lows anchored in the Hudson`s Bay and Great Lakes region, and also over California, and ridging in between. Ridge not strong enough to prevent various waves from moving through the Central Plains especially later Sunday and into the early work week. Backing up...rain chances look lower for most of the weekend although not completely out of the question. By the middle of next week the long term models transition to more of a zonal flow which would still give us small chances for rain. So while we will have off and on chances for rain, amounts should not be close to what we saw this past week. Highs will stay in the mid 70s to mid 80s which is near or just a few degrees warmer than the average for this time of year. Sat through Mon might be a tad cooler due to a cold front pushing through on Saturday with Sunday looking to be the coolest of the three. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Friday) Issued at 632 PM CDT Thu May 30 2019 Significant Wx: None. VFR conditions are expected through the period. We will continue to have a noticeable haze due to smoke from wildfires in Canada, however, this is not expected to affect surface vsbys at either of the terminals. Should see a few fair weather CU develop in the aftn tmrw, with bases around 5K ft. Winds will go lgt and vrbl this evening then turn SW around 10kt tmrw morning. Confidence: High. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ SHORT TERM...Ewald LONG TERM...Ewald AVIATION...Thies
Area Forecast Discussion
National Weather Service Grand Junction CO
954 PM MDT Thu May 30 2019 .SHORT TERM...(Tonight through Friday night) Issued at 313 PM MDT Thu May 30 2019 As expected, convection has fired over the higher terrain due to daytime heating a weak shortwave moving up from the south. The HRRR and NAMNEST have initialized quite nicely with this convection and they both indicate most convection will die down by sunset. A few showers, maybe even a storm or two, may continue past that as the wave continues to push through but without heating, we`ll effectively be done. By tomorrow morning, a large closed low will have set up over central California which keeps us in generally southerly flow. The polar jet will be over the Canadian border while the subtropical jet will be over Texas and northern Mexico. With no real features providing lift, aside from daytime heating, expect some showers and storms but coverage should be less than seen today and will favor the usual, higher terrain. This will be more of the pop and drop convection with some gusty outflow winds and heavier precip near and under the strongest cells. The rest of us? Partly cloudy skies as temperatures continue their upwards run. .LONG TERM...(Saturday through Thursday) Issued at 313 PM MDT Thu May 30 2019 The long term period will be affected by a cutoff low to our west through Wednesday. The low that is currently to our west will stay in that general area for the foreseeable future. The polar jet will stay to our north, the subtropical south and with nothing to get the low moving...well, that`s just it. There`s nothing to get it moving so it won`t. It`ll spin over the Great Basin for the next several days. The low will cause enough uplift for daily precip for NV, UT, and ID but we`ll be just on the periphery of this lift and won`t see much precip at all. Expect some convection over the higher terrain due to daytime heating but that`ll be about it. Cyclonic flow around the low will keep southerly flow going and by the start of next week, we will probably see some of our first 90 degree days...mostly over eastern Utah. The low finally does open up and become more of a trough by the weekend but it will still stay to the west. No troughs are upstream to get this feature moving until next Wednesday into Thursday. Time will tell. So expect sunshine with some high clouds moving overhead from time to time, a few showers/storms over the mountains, and temperatures reaching more summerlike temperatures. Not surprising as the start of summer is only 3 weeks off. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 952 PM MDT Thu May 30 2019 VFR pattern will be in place over the next 24 hours. The exception will be over the higher terrain where isolated shower and thunderstorms will develop after 17Z Friday. Gusty outflow winds to 40 kts will be the primary concern with any convection through Friday evening. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...TGR LONG TERM...TGR AVIATION...JDC
Area Forecast Discussion
National Weather Service Goodland KS
541 PM MDT Thu May 30 2019 .SHORT TERM...(Today through Saturday night) Issued at 130 PM MDT Thu May 30 2019 Today-Tonight: In general, expect dry conditions and a seasonably large diurnal temperature range with highs in the 70s to near ~80F and lows in the mid 40s to lower 50s. A vertically stacked low situated invof the central IA/MO border will weaken and progress ESE into the central MS River Valley this afternoon. An associated shear-axis extending westward along the NE/KS border will progress ESE into eastern KS and central MO through tonight. Subsidence on the western periphery of the upper low is expected to suppress convective development over the majority of the Tri- State area this afternoon, except perhaps in far northeast portions of the area where cool temperatures aloft (H5 T`s -15/-16C), lingering low-level moisture (SFC Td`s 48-54F), strong insolation (SFC T`s ~80F) and marginally steep mid-level lapse rates (6.5-7.0 C/km) will yield 500-1000 J/kg mlcape and forcing attendant the aforementioned shear axis (and a weak H85 reflection thereof) may be sufficient for convective initiation. HRRR and NAM NEST simulated reflectivity forecasts suggest that isolated sub-severe convection may develop invof Red Willow/Norton/Decatur counties between 21-00Z. Fri-Sat Night: Modest W to NW flow aloft will prevail in this period, on the northern periphery of an upper level ridge situated over portions of the Southern Rockies/Plains. Low-level southerly return flow, on the eastern periphery of a broad surface trough in the lee of the Rockies and the western periphery of an H85 ridge along the central Gulf Coast, will advect low-level moisture northward from the western GOMEX into the High Plains. Given that upstream convection is anticipated in TX on both Fri and Sat -- the northern extent and quality of moisture return into KS/CO remains uncertain. While isolated convection will certainly be possible during the late afternoon and evening hours, coverage/ intensity cannot be ascertained with much confidence. .LONG TERM...(Sunday through Thursday) Issued at 206 PM MDT Thu May 30 2019 A ridge sits over the central U.S. Sunday through Tuesday night. A closed low over southern California and Baja California Sunday, creating split flow aloft, begins to move east Wednesday. By Wednesday night, the closed low, embedded within a ridge, begins to impact the central Plains. The low begins the strengthen over the central Plains as a trough moves over the Pacific Northwest Thursday. Despite the ridging at upper levels, the surface remains active leading to chances for showers and thunderstorms throughout the extended forecast period. A stationary boundary sets up along the Front Range of the Rockies and into southwest Kansas Sunday leading to precipitation chances. This boundary moves east and out of the Tri-State region by Tuesday. A cold front is expected to move through the region by Wednesday, becoming stationary Wednesday night. High temperatures in the 70s and 80s are expected with lows in the 50s and 60s. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 539 PM MDT Thu May 30 2019 VFR conditions are expected throughout the TAF period at the McCook and Goodland terminals. Winds will become light and variable overnight, increasing tomorrow to around 10 mph shifting from the north, shifting to the NE near the end of the TAF period. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...VINCENT LONG TERM...NEWMAN AVIATION...EV
Area Forecast Discussion
National Weather Service Wilmington NC
1029 PM EDT Thu May 30 2019 .SYNOPSIS... The heat will finally start to gradually ease starting Friday and continue thru the weekend with max temps a few degrees lower each day from the previous day. Finally, there will be a bonafide threat for convection Fri afternoon and night. High pressure will continue to trend temperatures lower and back to normal by Tuesday of next week. && .NEAR TERM /THROUGH FRIDAY NIGHT/... As of 915 PM Thursday...Some svr tstorm action in NE Robeson County, ie. Parkton, earlier this evening with reports of damage. See the latest LSRs. Radar signatures at this juncture are pointing toward wind damage with further radar investigation needed for possibly a microburst/downburst being involved. No tornadic signatures stood out via KLTX radar 1st assessment. The activity along the central NC trof has pulled further NE into MHX CWA and activity over the ILM CWA has diminished with the loss of insolation and with the further inland progression of the sea breeze and stable low level marine layer. Have dropped POPs entirely by mid-evening. Have adjusted cloud coverage to account for convective debris that should thin and scour out rather quickly after midnight. Sfc winds will remain active enough to keep fog at bay and to keep min temps from dropping any further than the 70s both at the coast and inland. With SSTS around 80 already, Min temps at the immediate coast may only drop into the upper 70s. Previous...................................................... As of 300 PM Thursday...Heat continues across the Carolinas as drought conditions worsen. The latest U.S. Drought Monitor shows D1 (moderate drought) conditions extending along the coast with D0 (abnormally dry) extending a bit farther inland. In Wilmington rainfall over the past 120 days is almost seven inches below normal or 55% percent of normal, and today`s the 18th consecutive day with no measurable rainfall. Unless an isolated shower or t-storm can fire up in the next few hours across the Sandhills or along the seabreeze boundary, dry weather should continue through the night. A westerly low-level jet with 25-30 kt winds at 1000 feet AGL should help keep the boundary layer from stratifying out too much tonight. Recent MOS performance has shown a tendency for models to run as much as 3-5 degrees too cool with nighttime lows, so my forecast ranges from the mid to upper 70s for most locations. Beaches of Brunswick County could even see lows around 80 degrees tonight! These could be among the warmest daily low temperatures ever recorded this early in the year. A cold front will sink south across North Carolina Friday ahead of an approaching shortwave trough. Temperatures shouldn`t reach quite as hot as we`ve seen recently, remaining in the mid 90s for most locations away from the seabreeze. Models suggest convection will develop across central NC as cooler mid-level temperatures associated with the shortwave advect overhead late in the day. Instability of 1000-2000 J/kg and respectable wind shear for this late in the season should help organize storms into multicell clusters and perhaps bowing line segments, sinking south- southeastward. If storms become severe (we`re in an SPC `marginal risk`) strong winds and possibly some hail are the primary expected risks. The cold front should sweep off the coast shortly after midnight with slightly cooler and drier air advecting in on northwest winds. Record highs for Friday May 31 Wilmington 98 in 1953 Florence 102 in 1953 North Myrtle Beach 98 in 1953 Lumberton 99 in 2011 && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... As of 300 PM Thursday...Generally dry northwesterly flow anticipated Saturday and Saturday night. 20-ish POPs cannot be ruled out with surface trough in the area; the rain chances minimized by the northwesterly flow and very weak surface convergence associated with the trough. Highs not far from 90 and lows near 70 not as warm as recent weather but still solidly above climatology. && .LONG TERM /SUNDAY THROUGH THURSDAY/... As of 300 PM Thursday...Though the long term does not offer any appreciable rain chances it does at least offer more seasonable temperatures in start contrast to many recent days. Surface high pressure building in from the north will bring the only truly seasonable period Monday night through Tuesday night with lows in the mid 60s and highs in the low to mid 80s. Thereafter it will turn a few degrees warmer in weak return flow. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... As of 0Z....Predominantly VFR. Mostly clear skies overnight with few passing high clouds. Slight chance of stratus overnight off the coast at ILM, but confidence too low for TAF inclusion. Cloud deck around 5 kft will develop tomorrow afternoon ahead of an approaching cold front. Chance for thunderstorms tomorrow afternoon and evening, with marginal risk for an isolated severe storm, but have kept VCTS out of TAFs for now due to uncertainty in possible coverage. Southwest winds throughout TAF period, with gusts between 15 and 20 kts at coastal terminals through tomorrow. Extended Outlook...Mainly VFR into next week. Slight chance MVFR each morning in low stratus/fog, isolated to scattered TSTMs possible late Fri through Sat night. && .MARINE... For Tonight into Fri: As of 945 PM Thursday...Extended the SCA southward to Murrells Inlet. Based on latest readings and near term models, HRRR etc, SCA thresholds for 3 of the 4 ILM coastal zones will exhibit mainly occasional to frequent wind gusts to around 25 kt and seas 3 to 6 ft. The 6 footers for the new zone added to the ongoing SCA, AMZ254, will run 15 to 20+ nm out. Do not expect any convection over any of our area waters overnight into Fri. Wind driven waves at 5 to 6 seconds will dominate the local waters. Previous..................................................... For Tonight thru Fri Night: As of 300 PM Thursday...High pressure extends east-west across Florida and well out into the Atlantic. Southwest winds continue this afternoon across the Carolinas and should remain at a solid 15- 20 knots through the night, gradually building seas near Cape Fear to 4-6 feet. For this reason a Small Craft Advisory has been issued for the North Carolina waters for tonight into Friday morning. A cold front dipping south from Virginia will enter North Carolina Friday afternoon, sinking south into southeastern NC and northeastern SC Friday night. This front could be accompanied by a line of thunderstorms with gusty winds. Synoptic winds should shift to northwest behind the front after midnight. Seas currently range from 3-5 feet, highest near Cape Fear. Spectral wave analysis shows dominant wave period is around 6 seconds with virtually no longer period swell present. For Sat thru Tue: Light and somewhat variable flow Saturday and Saturday night with a very weak low just to our south keeping gradient poorly defined. As a more typical inland trough forms on Sunday winds will become southwesterly and increase by just a few knots. High pressure then builds in from the north on Monday turning winds northerly and possibly introducing a 3 ft wave to the forecast. As the high builds into Tuesday a slight veer to NE expected. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...Beach Hazards Statement from 6 AM EDT Friday through Friday evening for SCZ054-056. NC...Beach Hazards Statement from 6 AM EDT Friday through Friday evening for NCZ106-108. MARINE...Small Craft Advisory until noon EDT Friday for AMZ250-252-254. && $$ SYNOPSIS...DCH NEAR TERM...DCH/TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...VAO
Area Forecast Discussion
National Weather Service Lincoln IL
900 PM CDT Thu May 30 2019 .UPDATE... Issued at 900 PM CDT Thu May 30 2019 Active evening across the greater I-74 corridor with scattered storms, some producing large hail up to 1 inch diameter. Most of these storms were short-lived pulse type storms. A few areas received repeated, or training, thunderstorms and reached heavy, but localized precipitation totals. Overnight, the upper low that has been lingering well to the west for several days and is now moving into central IL, will finally pick up speed and move east of the area, with the remaining isolated showers and thunderstorms expected to end across central IL by around midnight. With drier and slightly cooler air moving in behind the system, expect lows to reach the upper 50s tonight. Current forecast incorporates these trends, and no significant updates are anticipated this evening. && .SHORT TERM...(This evening through Friday) ISSUED AT 257 PM CDT Thu May 30 2019 Weak NW-SE oriented surface trough extending from near Moline to just north of Lafayette, Indiana is triggering widely scattered convection this afternoon. An upper low centered further west over Iowa will provide additional lift along the boundary and should result in scattered showers/storms across much of the KILX CWA late this afternoon into early this evening. Based on radar trends and latest HRRR forecast, it appears convection will be most focused from Bloomington E/SE to Paris over the next few hours. Have therefore gone with 40 PoPs across this corridor, with 20-30 PoPs elsewhere. The convection will gradually dissipate this evening, followed by mostly clear and dry conditions overnight. Once the upper low passes to the east, short-wave ridging in its wake will provide mostly sunny and warm weather on Friday with highs in the lower 80s. .LONG TERM...(Friday night through Thursday) ISSUED AT 257 PM CDT Thu May 30 2019 The first part of the extended will be dominated by deep upper troughing over eastern Canada into New England...resulting in northwesterly flow across the Midwest. A short-wave trough embedded within the flow will track from southern Saskatchewan Friday morning into Illinois by Saturday. As this feature approaches, an associated cold front will interact with a moderately unstable/sheared environment to produce scattered thunderstorms during the afternoon and evening. With SBCAPE values progged to range from 1500-2500J/kg and 0-6km bulk shear of 30-40kt, think a few strong storms with large hail/damaging wind gusts will be possible. As such, SPC has highlighted locations north of the I-70 corridor for a Marginal Risk for severe on Saturday. Once the cold front passes, Canadian high pressure will build southward into the region and provide a period of cooler/drier weather for Sunday through Tuesday. After that, a return to unsettled conditions appears likely for the middle and end of next week as upper ridging tries to build back into the Midwest. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 652 PM CDT Thu May 30 2019 Scattered thunderstorms this evening, mainly along and north of the I-74 terminals in central IL, but otherwise VFR conditions. Thunderstorms should gradually shift eastward and diminish this evening, with all precipitation expected to be ended by 02-04Z. Winds generally westerly, with gusts to around 25 kts this evening, becoming light overnight. WNW winds up to 10 kts resuming by 17-18Z Friday. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...37 SHORT TERM...Barnes LONG TERM...Barnes AVIATION...37
Area Forecast Discussion
National Weather Service North Platte NE
636 PM CDT Thu May 30 2019 .SHORT TERM...(This evening through Friday night) Issued at 320 PM CDT Thu May 30 2019 The models- HREF, NAM and RAP, have picked on a nrn Plains upper air disturbance Friday afternoon and evening which should be sufficient for scattered showers and thunderstorms across nrn Nebraska. Instability in the RAP and NAM is good with up to 2500J/KG CAPE but winds aloft are on the weak side, generally less than 30Kt. This would support a more multicell ordinary storm mode as suggested by the Bulk Richardson number over 100 in the RAP model. The SPC day 2 outlook would support the same ordinary storm development. A stronger corridor of winds will lie south across southwest Nebraska and if these stronger winds, near 35Kt, can reach into northern Nebraska Friday afternoon then storm development could be more robust. Chance/low chance POPs are in place Friday afternoon and evening. The temperature forecast uses the guidance blend plus bias correction for lows in the 40s to mid 50s tonight, highs in the upper 70s to lower 80s Friday and lows in the upper 40s to mid 50s Friday night. This forecast might be a bit warm during the day and too cool at night. The wet conditions of late appear to be moderating the normal diurnal temperature curve. .LONG TERM...(Saturday through Thursday) Issued at 320 PM CDT Thu May 30 2019 The models are stronger with a cold front moving into wrn and ncntl Nebraska in the wake of the rain chance Friday. This appears to be having an obvious effect on temperatures and a more subtle effect on the rain chances this weekend. The blended temperature forecast came in a bit cooler with more days with highs in the upper 70s to around 80 and just one warm day, Tuesday, with highs in the lower to mid 80s. The stronger push of cold air is also forcing return moisture further west up the high Plains producing a more stable regime across ncntl Nebraska. The prospect of a ridge-runner type disturbance Sunday is low with this forecast as the better instability is across the high Plains of ern Colo and ern WY. Thus, we may have to wait until Monday to build up instability for stronger storm development. The forecast continues a chance POP late Sunday but this has shifted west toward swrn Nebraska and the upper level support appears weak. Isolated to low chance POPs are in place Monday and beyond for mostly diurnal storm activity. Winds aloft fairly weak, generally 20 to 30 kts and this would support ordinary storm development. The Laramie range, Cheyenne divide and Black Hills will be the most likely initiation areas for storms affecting western and north central Nebraska. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 614 PM CDT Thu May 30 2019 VFR conditions are expected over the next 24 hours. There is some haze aloft due to smoke from wildfires in Canada. Isolated showers have developed across western Nebraska moving WSW and should be dissipate after sunset. .HYDROLOGY... Issued at 320 PM CDT Thu May 30 2019 The NDOR continues to report highway 97 north of Mullen is impassable because of overland flooding. Several other highways across the Sandhills and north central Nebraska remain partially covered with flood water. The time to return to normal is uncertain because it appears the flooding is being partially driven by an abnormally high water table. Minor flooding is expected on the North Platte river above Lake McConaughy near Lewellen. Minor flooding is underway along the Elkhorn river above Ewing and near bankfull conditions are occurring on the Calamus river below Virginia Smith Dam. The Calamus reservoir is near capacity and releases through the dam spillway are driving the high water condition on the Calamus river. The Elkhorn river should remain high for a few days and the Calamus river will recede when the reservoir releases decrease. The North Platte river above McConaughy is expected to remain high for several days. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Gomez HYDROLOGY...CDC
Area Forecast Discussion
National Weather Service Medford OR
817 PM PDT Thu May 30 2019 .DISCUSSION...The persistent weather pattern continues, with about 300 lightning strikes in the past 6 hours, from the Cascades eastward and Siskiyous south. Less thunderstorms were observed today than we thought would be the case, but a few strong storms did form around Prospect at the foothills of the Cascades and diminished as they progressed southwestward. It was impressive to watch the individual updrafts of these storms on the Mesoscale GOES West satellite imagery this afternoon. We`ve taken thunderstorms out of the evening forecast for the Rogue Valley based on current radar and satellite trends, and we don`t anticipate adding a thunder chance tomorrow for West Side valleys. Flow and instability remains similar tomorrow...with a bit stronger northeast steering flow but less in the way of triggers as the dominant upper low feature moves farther to the south and away from the area. Additionally, WRF and HRRR output suggest storms staying over the Cascade foothills tomorrow. The forecast still looks on track through Friday. Regarding temperatures, if it felt warm today that`s because it was in many areas. Afternoon readings were 5 to 10 degrees above normal west of Cascades and near normal east of the Cascades. Afternoon temperatures will creep up on Friday by a few more degrees and peak over the weekend at about 10 degrees above normal. Please see the previous discussion from the dayshift about the weekend and beyond. && .AVIATION...For the 31/00Z TAFS...Along the coast and over the coastal waters...Areas of MVFR/IFR have already returned onshore this evening. The lower conditions will persist into Friday morning, burning back to the coast by early Friday afternoon. In the Umpqua basin...VFR conditions will prevail through late tonight, then areas of MVFR/IFR cigs in low clouds will move in. The lower conditions will clear to VFR by late Friday morning. Over the remainder of the west side...VFR conditions will prevail through Friday, but there will be isolated afternoon and evening thunderstorms, mostly from the Siskiyous south. From the Cascades east...VFR conditions will prevail through Friday, but there will be scattered afternoon and evening thunderstorms. Expect periods of MVFR/IFR in heavier precipitation. Winds will be gusty near thunderstorms and some higher terrain will be obscured. && .MARINE...Updated 200 PM PDT Thursday 30 May 2019...Not much change in the overall pattern is expected through at least early next week. The thermal trough along the coast and offshore high pressure will remain in place resulting in moderate to strong north winds and steep to very steep wind driven seas through at least the start of next week. With this long duration event, seas will gradually increase and steepen over time with very steep and hazardous seas likely occurring south of Gold Beach. Winds and seas will peak during the afternoons and evenings, with the strongest winds and highest seas south of Cape Blanco. As the thermal trough intensifies, conditions will deteriorate further starting Friday afternoon and lasting through Sunday. Hazardous seas will spread north to Cape Blanco with gales expected south of Gold Beach Friday afternoon through Sunday afternoon. Winds are expected to drop below gales Sunday night and the coverage area of hazardous seas warning conditions is also expected to shrink to just the outer waters beyond 20 nm from shore and south of Gold beach. Thus, adjustments were made to the headlines to reflect this. Please see MWWMFR for more information. Meanwhile, small craft advisory conditions will occur over the remainder of the area through Monday afternoon, and possibly beyond. The models are in fairly good agreement showing a weak front moving onshore Wednesday which should disrupt the strong northerly wind pattern. -Petrucelli && .PREV DISCUSSION... /Issued 146 PM PDT Thu May 30 2019/ DISCUSSION...Thunderstorms were quick to start this morning with cumulus build up starting early in the morning. Storms have also been very slow moving and rather disorganized. Satellite has shown some stronger updrafts, specifically in northern California, but we`re still confident that severe storms are unlikely this evening. Some of these thunderstorms will still be capable of locally stronger wind gusts up to 40 mph or so, especially if they are able to make it west of the Cascades. Thunderstorm activity will drop off later tonight as we lose surface heating. It will be interesting to see how lingering cloud cover may impact storm activity tomorrow since surface heating is what is kicking off storms. Irregardless, we have have high confidence we`ll see more thunderstorms tomorrow. The upper level low will begin to dive farther south into southern California on Saturday. As a result, our thunderstorm chances will lower compared to the last few days. Models still want to initiate thunderstorms east of the Cascades and over northern California with light and variable flow on Saturday. Again, surface heating will be the trigger mechanism here, but we expect thunderstorms will be more isolated compared to the last few days. High pressure will begin to gradually build on Sunday with light onshore flow. Temperatures will be roughly 10 degrees above average for this time of year in most of our area, so we`ll start off June warmer than average. -Smith Long term discussion...Mon 03 Jun through Thu 06 Jun 2019. The extended forecast period will begin with persistent cutoff low over southern California and a flat upper ridge off the west coast. The low will slowly move southward with time and the offshore ridge will weaken as a long wave trough deepens well offshore. This will bring the upper level flow around to roughly zonal Monday into Tuesday. The short waves rotating around the low will also be farther south, so overall the air mass over the Medford CWA will become drier and more stable with time. If there are any showers or thunderstorms during this interval, it will be toward the southern border of the Medford CWA in the afternoons and evenings. At this time, will go with isolated thunderstorms over southeast Modoc and southeast Lake counties Monday, but will go with dry forecast Tuesday. Inland highs will be 10-15 degrees above normal, except 5- 10 degrees above normal in the Umpqua Basin. The offshore upper level trough will progress and deepen a bit, and the flow aloft will become southwesterly Wednesday. The front associated with the trough will still be well offshore Wednesday, so no precipitation associated with it is expected through Wednesday night. Showers and thunderstorms over the east side remain a possibility, but a remote one at this time. Inland highs will be a few degrees cooler than the Tuesday highs. The medium-range models solution have converged since yesterday, and all of them move a long wave trough onshore Thursday. The associated front will move onshore Wednesday night. At this time it looks like any precipitation will be light, and even that will be pushing it. The forecast will have some showers over the northern Cascades Thursday evening, but that`s it. The main effect for most of the area will be a onshore marine push Thursday, bringing cooler temperatures to the area. The EC extended guidance drops the inland highs to near normal values, while the GFS guidance suggests highs up to around 5 degrees above normal. -Stockton && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. Pacific Coastal Waters...Small Craft Advisory until 5 PM PDT Monday for PZZ350-356-370-376. Hazardous Seas Warning until 5 PM PDT Sunday for PZZ356-376. Gale Warning from 2 PM Friday to 5 PM PDT Sunday for PZZ376. $$
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
706 PM CDT Thu May 30 2019 .Updated for 00Z Aviation Discussion... Issued at 653 PM CDT Thu May 30 2019 && .SHORT TERM...(This evening through Friday night) Issued at 300 PM CDT Thu May 30 2019 The short term concerns are extent of any convection this evening and again Friday afternoon/night. Also, smoke from Canadian fires has moved into the area and will likely affect the region into Friday night. Latest satellite showing thicker smoke has drifted a bit farther south across far southern MN. Various smoke dispersion models indicated this trend as well. It did little to affect temperatures overall as we were able to warm to early forecast highs. Models indicate smoke to be thinner Friday until the cold front drops south over the area mainly Friday night. Water vapor imagery showing high clouds dropping south across northern MN at this time. Little in the way of layered clouds, and convective trends dont look very promising. The 12z GFS and FV3 were very bullish in developing more widespread convection as that system dropped south over the area this evening. The NAM and other HIRES solution were less so with the HRRR trend even drier last few runs. Will have to carry small chance of thunder across the northern CWA into the evening. Still should see a diurnal trend overall with any activity dissipating around sunset. Warming out ahead of the incoming cold front should boost temperatures into the mid and upper 80s across most of the area Friday afternoon. Westerly winds increase and becoming gusty late morning/afternoon. Gusts to 25 kts likely across the northern CWA. Increasing thunder threat develops with the approach of the cold front Friday afternoon. Will inquirer`s PoPs to likely for the evening spreading south overnight. Sever threat does look possible, with the main overall hazard strong wind gusts due to the inverted V sounding in the well mixed airmass ahead of the front. Hail also will be possible with steep mid level lapse rates around 7-7.5 C/km. MLCAPE to 2000 J/kg forecast along with best LI`s to minus 8 and bulk shear 30 to 45 kts are all favorable for the severe weather threat. This gradual tapers off north to south later Friday night with passage of the cold front. .LONG TERM...(Saturday through Thursday) Issued at 300 PM CDT Thu May 30 2019 By Saturday morning, there could be a few showers remaining across far southern MN but will quickly exit to the southeast with the frontal boundary referenced in the short term discussion. Cold air advection aloft will follow as an upper low digs south across Ontario into the northern Great Lakes Saturday through Sunday. Deep northwesterly flow will remain in place locally and 850mb temps will fall to near +2 C. At the surface, high pressure will slide in from the north, bringing dew points likely in the lower 30s with it. There could be a scattered cu field Saturday given the cold air aloft and cyclonic flow still moving through. Upper ridging will push in for Saturday night into Sunday, so confidence is higher that Sunday will be partly cloudy. On top of that, the surface high itself looks to move directly through our local area Sunday, so winds will be lighter. Overnight temperatures will likely dip into the 40s area wide Saturday night, with a few upper 30s not out of the question. By early next week, the upper ridge spreads across the Upper Midwest as does a warmer and more moist air mass. Timing differences remain in the model guidance, but there is some consistency in the models wanting to develop a shortwave along the ridge through southern/central MN and western WI. The best chance of thunderstorms at this time looks to be on Tuesday-Tuesday night, but capped the PoPs at 50 percent for now given uncertainty and timing differences. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 653 PM CDT Thu May 30 2019 VFR conditions throughout. Light winds overnight will increase and become more westerly on Friday ahead of a cold front that will bring more northerly winds and scattered showers and thunderstorms. KMSP... VFR conditions throughout. Light winds overnight will increase and become more westerly on Friday ahead of a cold front that will bring more northerly winds and scattered showers and thunderstorms. The best chance for storms is after 00Z at KMSP. /OUTLOOK FOR KMSP/ Sat...VFR. Wind N 10G15 kts. Sun...VFR. Wind NW 5-10 kts. Mon...VFR. Chance TSRA/MVFR late. Winds SE 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...DWE LONG TERM...SPD AVIATION...JRB
Area Forecast Discussion
National Weather Service Marquette MI
1015 PM EDT Thu May 30 2019 .UPDATE... Issued at 1015 PM EDT THU MAY 30 2019 No changes planned for frost advy headlines this evening. Low-levels dried out significantly this aftn over the e where mixing to very dry air aloft caused sfc dwpts to crash. That drier air has been advecting westward this evening. Latest ob from KSAW has dwpt at 21F. Fcst soundings from hourly RAP/HRRR runs and 18z GFS/NAM suggest a rather rapid development/increase in mid clouds during the overnight under waa regime shifting ese in association with shortwave moving from Manitoba into northern Ontario. Initial dry air mass supports a quick drop in temps over the next several hrs. Whether it cools enough for frost development before clouds arrive is somewhat uncertain, but retaining frost advy seems prudent given the initial dry conditions and essentially calm winds. To the w, earlier arrival of clouds suggests no westward expansion of frost advy is warranted. As more focused/sharper waa arrives late tonight/Fri morning, expect some shra to spread ese across mainly northern and eastern Lake Superior where waa is sharpest, but a few shra could affect portions of northern and eastern Upper MI. Given a little instability for parcels lifted from 850mb or higher, not totally out of the question that there could be a rumble of thunder. && .SHORT TERM...(This evening through Friday) Issued at 356 PM EDT THU MAY 30 2019 WV imagery and RAP analysis indicated nw mid/upper level flow between a low east of James Bay and a ridge through the northern Plains. An upstream shortwave trough was sliding southeast through northern Saskatchewan and northern Manitoba. At the surface, high pressure extended from nw Ontario into Upper Michigan. Northerly winds have kept temps in the upper 40s to mid 50s north with readings into the mid 70s south. WAA ahead of a sfc low into se Saskatchewan supported mid/high clouds through ne MN into wrn Upper Michigan. Smoke from wildfires in parts of western and central Canada had over much of the Upper MS valley and through the west half of Upper Michigan but was slowly retreating to the southwest. Tonight into Friday morning, with favorable radiational cooling conditions at least during the evening and early overnight, the forecast maintains temps toward the lower end of guidance for inland locations over the east half. Readings into the lower 30s at favored cold spots could result in patchy/areas frost inland over the east half where a frost advisory has been issued. Some increase in clouds expected overnight with increasing mid-level moisture and weak forcing ahead of a shortwave and associated sfc low moving down from southern Canada may stop temps from falling or cause a slight rise in temps late, especially over the west. Late tonight and Friday morning, WAA and isentropic lift ahead of the sfc low will bring the potential for some light rain into the north and east between 08z- 12z. Friday afternoon, a shortwave trough diving se through Ontario will drag a cold front into the region. WAA and moisture advection ahead of the front will bring MLCAPE values to around 1k J/Kg range for counties along the WI border by Friday afternoon. As the front approaches, expect sct/isold t-storms will develop over south central upper Michigan bylate afternoon. Deep layer mainly unidirectional 0-6km shear to 45 knots will support potential for a few storms with large hail and damaging winds. .LONG TERM...(Friday night through Thursday) Issued at 412 PM EDT THU MAY 30 2019 With a negative NAO, and associated ridge over the Northern Atlantic, a low pressure and its associated low heights are blocked to the north of the Great Lakes. This will contribute to predominately NW flow aloft through Monday evening, with the exception for when a few troughs pass through the area. Starting Friday night, there may be a few storms lingering around in south central and perhaps eastern UP, along Lake Michigan. Although the CAPE is slightly elevated, MLCAPE on the NAM is in excess of 1000 J/kg. The best shear remains detached from the main feed of CAPE; however, 3km helicity values in surplus of 300m2/s2 suggests a chance for a thunderstorm to go severe. For Saturday, skies will clear some in the afternoon as slight high pressure moves into Upper Michigan. On Sunday, a sharp upper level trough will dig through Upper Michigan bringing a chance for showers mainly for north and eastern UP. Except this to bring temperatures down into the 50s on Sunday before rebounding into the 60s on Monday as an upper level ridge and surface high pressure approach Upper Michigan from the west. As this ridge pushes through Tuesday, GFS shows zonal flow aloft will return through the end of the week. On Tuesday night into Wednesday, low pressure and an associated trough will pass through the CWA bringing scattered showers and a chance at a thunderstorm of two. Models differ on this solution at the moment with the Canadian running 6 to 12 hours behind current GFS and ECMWF runs. High pressure after this low and frontal passage should keep the area dry through the week, with temperatures moderating back into the 70s. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 735 PM EDT THU MAY 30 2019 VFR conditions are likely to prevail thru the fcst period at KIWD/KCMX/KSAW. There there may be some -shra and possibly a thunderstorm late tonight into Fri morning across portions of northern and eastern Upper MI. However, the probability of KCMX or KSAW being impacted still remains too low to include mention in the TAF. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 356 PM EDT THU MAY 30 2019 High pressure building over the area tonight will bring diminishing winds. Winds will remain at or below 20 knots into early next week. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Frost Advisory until 8 AM EDT Friday for MIZ006-007-013-014-085. Lake Superior... None. Lake Michigan... None. && $$ UPDATE...Rolfson SHORT TERM...JLB LONG TERM...JAW AVIATION...Rolfson MARINE...JLB
Area Forecast Discussion
National Weather Service Omaha/Valley NE
943 PM CDT Thu May 30 2019 .UPDATE... Issued at 929 PM CDT Thu May 30 2019 No changes to the ongoing forecast. However, you may have noticed, there is a fairly dense layer of Canadian wildfire smoke that has settled across the region today. While it`s not visible at night, vertically integrated smoke model output from both the HRRR and RAP suggest that it will still be there in the morning, and for much of the day Friday. We believe the smoke is very high, above 20,000, based on the METAR observation from Sioux Falls, SD (KFSD). Surface smoke forecasts suggests that most of this stays aloft, however some could mix down in northeast NE. airnow.gov is currently reporting moderate air quality in northeast NE, and unhealthful air quality in eastern SD, although no observing sites are reporting any visibility restrictions. Expect hazy sunshine on Friday, enough that it could feel partly cloudy, instead of the mostly sunny skies that we are expecting. && .SHORT TERM...(Tonight through Sunday) Issued at 330 PM CDT Thu May 30 2019 Forecast concerns in the very short term are isolated thunderstorms through early evening and the increasing smoke drifting southward from northern Minnesota/the Canadian fires. The closed mid-tropospheric low over northern Missouri with trailing trough energy into southwest Iowa and southeast Nebraska will gradually drift southeast. H85 moisture is still around 7 to 9 deg. C with around 2K J/kg sfc based CAPE through around 01Z. The non-supercell tornado parameter on the SPC mesoscale analysis page has parts of southwest Iowa into northern Missouri around 4 with low level vorticity present. A funnel cloud cannot be ruled out, but better chances closed to the h5 low. Visible satellite imagery shows the cumulus field into eastern Nebraska with a few pop-up showers and thunderstorms that will rotate around and gradually drift southeast out of the area through peak heating/sunset. The smoke on visible satellite has made it to the Platte River, so we will see the smoke haze coming in from the north. Fortunately, surface visibilities remain above 8 miles at most spots. A weak ridge builds in for tonight with the next couple of shortwaves tracking across the Dakotas into northern Nebraska and another across Kansas. The shortwave over the Dakotas strengthens with a band of showers and thunderstorms from northern Nebraska into SD later Friday afternoon through Saturday morning as a front is dragged through the forecast area. Some strong to severe storms possible, although they may be just northeast of the forecast area or in parts of our western Iowa counties where the moisture and forcing come together better early Saturday. Surface high pressure builds in for Saturday night with deceasing north winds. Sunday is looking quite pleasant with dewpoints dropping back into the 40s to lower 50s! Highs Friday in the 80s...70s and 80s Saturday and 80s for Sunday. .LONG TERM...(Sunday night through Thursday) Issued at 330 PM CDT Thu May 30 2019 No significant rainfall or organized severe weather is forecast at this time. However with highs in the 80s Tues/Thur will need to keep up with any boundaries or pockets of moisture in the area. The next chance for spotty showers/thunderstorms will be Monday, with a better chance Monday night...spotty Tuesday through Thursday. The pattern has a mid-level trough over California and Nevada with a ridge over the Western Plains. Weak energy moves through the ridge and breaks down early in the week as the closed low over California drifts toward Baja. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 610 PM CDT Thu May 30 2019 VFR conditions through the period. There is a broken smoke layer across the region. Smoke layer could be around 20-25,000, based on the METAR observation at FSD. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ UPDATE...DeWald SHORT TERM...Zapotocny LONG TERM...Zapotocny AVIATION...DeWald
Area Forecast Discussion
National Weather Service Great Falls MT
820 PM MDT Thu May 30 2019 .UPDATE... Most of the forecast through tomorrow morning remains valid. However, freshened hourly temperatures and other pertinent variables for the next few hours to better match observed trends. A Canadian cold front is beginning to cross our Hi-Line counties and should stall along the Rocky Mountain Front over the next few hours and central Montana mountains during the predawn hours of Friday morning. Isolated showers and thunderstorms are present along this front. Despite boundary layer stabilization via nocturnal cooling, these showers and thunderstorms may persist through Friday morning given the potential for weak, elevated instability ahead of the front. As northwesterly flow aloft and embedded disturbances affect our area through Friday morning, additional and isolated showers and thunderstorms are possible elsewhere, especially later Friday morning, when instability increases via daytime heating. Lastly, satellite imagery shows extensive smoke from Alberta wildfires is present behind the Canadian cold front. However, smoke forecasts from the HRRR and Canadian Firework Model suggest the smoke will continue to disperse and have little impact on air quality or visibility across north-central Montana. This smoke will continue to be monitored closely and future adjustments to our forecast may be needed if the smoke is thicker than anticipated currently. - Jaszka && .SYNOPSIS... Scattered showers and thunderstorms remain possible through Friday, especially during the afternoon and evening hours of today and Friday. A weak cold frontal passage will slow the recent warming trend on Friday. Dry conditions return this weekend as temperatures climb back above average. && .AVIATION... Updated 452 PM MDT Thu May 30 2019 (00Z/Fri TAFs) Mainly VFR, westerly to northwesterly mid- to upper-level flow, and embedded disturbances affect our area during the next 24-hours. Isolated to scattered showers and thunderstorms are expected, especially through this evening, and again during the afternoon and early evening on Friday. Accordingly, brief MVFR may accompany any shower or storm. While regional winds will be light, erratic winds gusting up to 45 knots are possible in/near any shower or thunderstorm. Brief, torrential rainfall is possible with any shower or storm and any thunderstorm may also produce small hail. - Jaszka && .PREV DISCUSSION... /ISSUED 237 PM MDT Thu May 30 2019/ Rest of this Afternoon through Friday Night...Cold front aloft continues to move south across central Montana this afternoon, and is serving as the trigger for more widespread shower and thunderstorm development over northern and central Lewis and Clark County and southwestern Teton County. The remnants of this front will stall along the mountains-plains interface through Friday, with increasing moisture and instability behind the front helping to trigger additional showers and thunderstorms which will be most concentrated along and near where flooding impacted the Rocky Mountain Front earlier this week. Slow-moving showers and thunderstorms can be expected across much of the rest of the area except for far northeast sections where conditions will remain largely dry. With weak flow, weak to moderate instability any thunderstorms should remain below severe levels, with heavy rain, small hail, frequent lightning, and gusty winds the primary threats. This Weekend through Thursday...Upper-level ridging strengthens through the weekend. Although a few mainly mountain thundershowers can`t be ruled out, most areas will enjoy warm, breezy and dry conditions, with the warmest temperatures of the year so far. A weak cold front will knock down the temperatures a bit on Tuesday but may bring breezy an dry conditions to the plains resulting in elevated fire weather conditions. Fair weather continues with seasonal temperatures under a dry zonal flow aloft Wednesday and Thursday. && .HYDROLOGY... Runoff from the heavy rain and snowmelt last weekend has moved away from the Rocky Mountain Front as river level crests move farther downstream. All Flood Warnings have been cancelled except for the Teton River between Dutton and Loma. Any increase or decrease in releases from Gibson Dam will have a significant impact on water levels on the Sun River, so river levels may remain near or at minor flood stage for several days. Warmer temperatures will continue to produce snowmelt runoff, so water levels will need to be monitored for changes. The big unknown remains slow-moving shower and thunderstorm potential and how much the associated runoff affects the main-stem rivers through the end of this week. && .PRELIMINARY POINT TEMPS/POPS... GTF 52 70 50 78 / 20 40 10 10 CTB 50 71 48 78 / 40 30 10 10 HLN 51 72 49 79 / 20 60 20 30 BZN 46 72 45 77 / 20 60 10 20 WEY 36 66 36 68 / 30 30 30 30 DLN 44 72 44 74 / 20 50 30 50 HVR 53 77 51 82 / 10 20 10 0 LWT 49 68 47 75 / 10 60 10 50 && .TFX WATCHES/WARNINGS/ADVISORIES... Flood Watch through Saturday morning Cascade...Central and Southern Lewis and Clark...Eastern Glacier...Eastern Pondera... Eastern Teton...Northern Rocky Mountain Front...Southern Rocky Mountain Front. && $$ http://www.weather.gov/greatfalls