Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/16/18


Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
818 PM CDT Fri Jun 15 2018 .UPDATE... Issued at 813 PM CDT Fri Jun 15 2018 Made a few changes this evening. CAMS are consistent in developing an MCS on the head of the LLJ overnight. Problem is temps are still quite warm aloft...ie +12C at H7 or higher. Due to CAM consistency have bumped up pops a notch over mainly sc/se CWA where LLJ should be focused late tonight. Temperatures look okay for the most part. && .SHORT TERM...(This Evening through Saturday Afternoon) Issued at 332 PM CDT Fri Jun 15 2018 Late this afternoon, a surface frontal boundary was extending from northeast SD and then southwest into central Nebraska. There was a weak surface low pressure area on this boundary in northeast SD. The issue tonight will be if the lift from a short wave trough moving in from the southwest will be enough to overcome the warmer mid level temperatures. Some of the models indicate this will occur with showers and storms developing with good qpf like the gfs and hrrr while the nam and rap13 showed little if any qpf. At any rate, there will be plenty of instability and moisture available to the storms if they can get going. Have in chance pops tonight/early Saturday morning. Otherwise, there looks to be a break for Saturday morning into the early afternoon for much of the cwa before another short wave trough makes its way into the region for the late afternoon. With surface heating and continued good instability, deep layer wind shear, and cooler mid level temperatures, thunderstorms are expected to develop. With precipitable waters getting up to close to 2 inches with the help of the moisture from tropical system Bud, heavy rainfall could occur with these storms. .LONG TERM...(Saturday Evening through Friday) Issued at 332 PM CDT Fri Jun 15 2018 The threat for heavy rainfall, as well as severe storms, Saturday night through Sunday night will be the main concerns in the long term. The period begins with an upper level ridge over the Ohio Valley with southwesterly flow over this region. Remnants from Hurricane Bud will likely bring record to near record PWATS, especially 0Z Sunday. Both the NAM/GFS show PWATS of 1.90 inches, which would rank in the top ten highest values for June. While not outside the climatological mean, NAEFS return interval does indicate the high PWATS occur once every 5 to 10 years. A possible rare rainfall record is at stake. Remnants from Hurricane Lester in August, 1992 produced 3.29 inches of rain in southeast SD. The 3.29 inches is the most SD has seen from a tropical cyclone since 1950. It is possible this record could be broken Saturday through Sunday. With a 40 to 50 knot LLJ, gradient of instability, severe storms will be possible Saturday night into early Sunday morning. Instability quickly wanes on Sunday with the severe threat best south of this CWA. Conditions should dry out early next week before pcpn chances move back into the region late next week. && .AVIATION...(For the 00Z TAFS through 00Z Saturday Evening) Issued at 617 PM CDT Fri Jun 15 2018 VFR skies/vsbys are generally expected overnight. However, thunderstorms are also possible, therefore relatively brief periods of IFR conditions can be expected with any thunderstorms. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...TDK SHORT TERM...Mohr LONG TERM...SD AVIATION...TDK
Area Forecast Discussion
National Weather Service Albany NY
1003 PM EDT Fri Jun 15 2018 .SYNOPSIS... The last upper level disturbance will push southward tonight with clearing skies. Dry and seasonable conditions are expected to start the weekend as high pressure slides across the region. Then a warm front approaches the second half of the weekend which will lead to summer like weather for early next week. && .NEAR TERM /THROUGH SATURDAY/... As of 1000 PM EDT, clear skies prevail this evening with temperatures already cooling into the 50s. No changes were made to the forecast at this time outside of refreshing the hourly temps. Prev Disc...As of 740 PM EDT, latest visible imagery indicates clearing skies this evening. This, along with light winds, will lead to good radiational cooling and temperatures dipping into the upper 40s to lower 50s overnight. So have tweaked sky grids and hourly temps to reflect recent obs. Otherwise, the forecast remains on track this evening. Prev Disc...As of 330 PM EDT...One last short wave within our northwest flow regime per the enhanced layered GOES-16 H2O Vapor channels was rotating southward near or just wet of the I81 corridor. GOES-16 Visible Red channel indicates enhanced cumulus field from the Dacks, western Mohawk Valley into the Catskills and mid-Hudson Valley yet radar reflectivities are thus-far nil of activity. Per HRRR and forecast profiles, still the small window of opportunity for an isolated shower across the terrain west of the Hudson through the balance of the afternoon hours. As this wave tracks south this evening, increasing subsidence and loss of daytime heating should result in a clearing sky. As winds subside, should be a tranquil period of weather tonight as overnight lows dip back mainly into the 50s with some upper 40s across the higher terrain. Saturday...The aforementioned surface high slides off the mid- Atlantic coastline leaving behind a slight increase in those westerly winds. There could be some convective debris in the form of cirrus thanks to potential MCS across the upper Mississippi River Valley that could spill over the ridge but an overall a nice day is on tap. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... Saturday Night...As the upper ridge builds upstream and begins to track eastward, warm front becomes a bit more defined per the thermal packing in the lower levels upstream. NCEP Model Suite while over similar synoptic setup, they do differ on the degree of instability and whether enough forcing will occur for convection to evolve along the boundary and track into eastern NY. We will cut back the slight chance PoPs to mainly Herkimer County and just west of the Catskills overnight at this time. Overnight lows generally within a couple degrees of the range between 55-60F. Sunday (Father`s Day) will feature increasingly more humid conditions and warming temperatures as the warm front slides across the region. The main challenge of the day is what, if any, convection develops or occurs along the warm front as it progresses through. The NAM keeps things rather capped where as the global models are a bit more robust with convective potential. Given the strength of the increase baroclinicity and low level jet dynamics of magnitudes approaching 30kts and Showalter values dropping below 0C, we will retain the previous excellent forecast of chance PoPs along and north of I90 with slight chance to the south. Temperatures under a diverse cloud coverage should climb into the 80s across majority of the county warning area (CWA). Sunday night...We become well established in the warm sector as dewpoints climb well into the 60s and perhaps near 70F overnight as main focus with convection should remain north of of I90. However, as it will be rather close with frontal position and close coordination with neighboring WFOs, we will retain the graduated PoPs with chance along and north of I90 overnight and slight chance to the south. A H850 temperatures approach +21C overnight, should be rather muggy with overnight lows generally into the 60s and lower 70s. && .LONG TERM /MONDAY THROUGH FRIDAY/... A hot opener will quickly turn dry and seasonably warm. Monday will be the second day of a hot start to the week. A cold front sliding south through eastern New York and adjacent western New England promises to bring showers, thunderstorms and an end to the extreme heat by the end of the day on Monday. High temperatures on Monday will range from around 80 degrees in the high peaks of the Adirondacks and Greens, to the mid 90s down the Hudson Valley, with upper 60s to mid 80s on Tuesday. Lower 80s will be the max on Wednesday. With weak high pressure in control through the remainder of the week, high readings will level off slightly above normal for the balance of the work week. Lows Monday night will range from the upper 50s to lower 70s, with around 50 degrees to the lower 60s Tuesday night. Overnight readings will begin to moderate somewhat thereafter. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... VFR conditions will prevail through the forecast period with perhaps some passing mid or high level clouds during the day tomorrow. Winds will be light and variable, generally less than 6 kts. Outlook... Saturday Night: No Operational Impact. NO SIG WX. Sunday: Low Operational Impact. Slight Chance of SHRA...TSRA. Sunday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. Monday: Moderate Operational Impact. Chance of SHRA...TSRA. Monday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Tuesday: Moderate Operational Impact. Chance of SHRA. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... An upper level disturbance will move off the New England coast by this evening, with isolated showers ending mainly to the west of the Hudson. Clouds will gradually decrease tonight, with clearing skies and light winds. Conditions will become increasingly warm and humid over the weekend into early next week, with a chance for showers and thunderstorms returning by Sunday as well. RH values will increase to around 75 to 100 percent tonight. Minimum RH values on Saturday will be around 30 to 40 percent. Winds tonight will become northwest around 5 mph or less. Winds on Saturday will be northwest around 5 to 10 mph. && .HYDROLOGY... No hydrological problems are anticipated into early next week. Dry weather is expected from this evening through Saturday night. This should allow rivers, creeks, brooks, lakes, reservoirs, and streams levels to either hold steady or slowly fall. The next chance of showers and thunderstorms arrives Sunday into Monday, as a frontal boundary approaches and slowly pushes south across the region. With an increasingly hot and humid air mass, some heavy downpours may occur. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...BGM NEAR TERM...BGM/JVM SHORT TERM...BGM LONG TERM...ELH/Wasula AVIATION...Frugis/JVM FIRE WEATHER...BGM/JPV HYDROLOGY...BGM/JPV
Area Forecast Discussion
National Weather Service La Crosse WI
638 PM CDT Fri Jun 15 2018 .SHORT TERM...(This evening through Sunday) Issued at 350 PM CDT Fri Jun 15 2018 At 3 PM, a mesoscale convective complex was moving through the Twin Cities. This system was producing scattered showers and storms across east-central, southeast, and south-central Minnesota, and north-central Iowa. The HRRR and ARW have the best handle on this precipitation. As the afternoon progresses, these showers and storms will eventually build across Wabasha and Dodge counties in southeast Minnesota and along and north of Interstate 94 in western Wisconsin late this afternoon and early evening. As this convection builds and develops a cold pool, the HRRR pushes it south toward Interstate 90. Considering the cap strength, this seems a bit unrealistic, so trended the PoPs along and north of Interstate 94. We will have to watch these storms for the potential of an isolated severe storm. Damaging winds, hail, and very heavy rain will be the main concerns. As the low level jet increases the moisture transport into eastern South Dakota, a mesoscale convective complex will develop. It will then move northeast across southwest and central Minnesota. A few of these storms may move through north-central Wisconsin. With weak 2-6 km shear, any severe weather will likely be more isolated than widespread. However, if a large enough cold pool happens to develop, a squall line may develop with damaging winds the main concern. Additional storms will be possible north of Interstate 94 through the weekend. With precipitable water values running between 1.5 and 2 inches and warm cloud layer depths of 3.5 to 4 km through the weekend, any storms that do develop will be capable of producing very heavy rain. On Saturday and Sunday afternoons, high temperatures will climb to around 90 north of Interstate 90 and in the lower and mid 90s across the remainder of the region. With these temperatures and dew points around 70, afternoon and evening heat indices will climb into the 90 to 105 degree range. Due to this, we have issued a Heat Advisory from 1 PM Saturday through 7 PM Sunday. With 850 mb temperature anomalies around 2 standard deviations, there may be a few record highs tied or broken. These records can be found in the climate section below. .LONG TERM...(Sunday night through Friday) Issued at 350 PM CDT Fri Jun 15 2018 From Sunday night through Monday evening, a cold front will move slowly southeast through the Upper Mississippi River Valley. Ahead of this front ML CAPES will climb into the 1500 to 3000 J/kg. However, the 0-3 and 0-6 km shear remains weak, so any severe weather does happen to develop will be isolated in nature. With precipitable water values running between 1.5 and 2 inches and warm cloud layer depths of 3.5 to 4 km through the weekend, any storms that do develop will be capable of producing very heavy rain. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 638 PM CDT Fri Jun 15 2018 Thunderstorms continue to track just north of LSE and should remain there the next few hours, with just some thicker "blow-off" cirrus for RST/LSE expected. Based on current trends, it appears additional storms will develop toward central Minnesota later tonight, again likely missing RST and LSE and leaving VFR conditions intact, though of course we`re dealing with convection here and we`ll have to watch trends closely in the near term. Winds will settle down a bit overnight, generally out of the south/southeast 8-12 knots, allowing low level wind shear to develop at RST. Winds will then ramp up again on Saturday, gusting 20-25 knots through the afternoon with any additional storms likely holding north of the TAF sites. && .CLIMATE... Issued at 350 PM CDT Fri Jun 15 2018 Here are some record highs for Saturday... Austin MN 93F in 1987 Charles City IA 96F in 1933 Cresco IA 92F in 1946 Decorah IA 97F in 1910 La Crosse WI 94F in 1994 Mauston WI 92F in 2007 Medford WI 94F in 1898 Neillsville WI 94F in 1907 Prairie du Chien WI 96F in 1987 Rochester MN 99F in 1913 Sparta WI 95F in 1918 Winona MN 94F in 1987 Here are some record highs for Sunday... Austin MN 93F in 1995 Charles City IA 95F in 1913 Cresco IA 92F in 1940 Decorah IA 98F in 1910 La Crosse WI 95F in 1995 Mauston WI 93F in 1918 Medford WI 93F in 1907 Neillsville WI 95F in 1910 Prairie du Chien WI 96F in 1987 Rochester MN 94F in 1933 Sparta WI 93F in 1934 Winona MN 97F in 1933 && .ARX WATCHES/WARNINGS/ADVISORIES... WI...Heat Advisory from 1 PM Saturday to 7 PM CDT Sunday for WIZ032>034-041>044-053>055-061. MN...Heat Advisory from 1 PM Saturday to 7 PM CDT Sunday for MNZ079- 086>088-094>096. IA...Heat Advisory from 1 PM Saturday to 7 PM CDT Sunday for IAZ008>011-018-019-029-030. && $$ SHORT TERM...Boyne LONG TERM...Boyne AVIATION...Lawrence CLIMATE...Boyne
Area Forecast Discussion
National Weather Service Columbia SC
1007 PM EDT Fri Jun 15 2018 .SYNOPSIS... Weak frontal boundary over the Midlands and Pee Dee will slowly move southward today and stall near the CSRA Saturday. High pressure and a building upper level ridge will control the region for Sunday into late next week. This scenario will keep chances of mainly afternoon and evening thunderstorms in the forecast with rising temperatures through late next week. && .NEAR TERM /UNTIL 7 AM SATURDAY MORNING/... A frontal boundary/dewpoint gradient remains situated across the Midlands. A warm moist airmass along and south of the front has fueled thunderstorms development. Dry air aloft is keeping coverage scattered, but it has also allowed some storms to become severe with outflow winds around 60 mph. The strongest storms are now located in Sumter and Clarendon County, with isolated storms elsewhere. Converging outflow boundaries could allow activity to persist for several more hours. But overall, strength and coverage should continue to diminish from this point forward with the loss of daytime heating and drier low level air filtering in from the north. Overnight lows will generally be in the low 70s, except upper 60s to the north. && .SHORT TERM /7 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... Upper level ridge over the MS River Valley will slowly build east Saturday as the upper trough off the east coast moves out to sea. The remains of a surface front will be near the CSRA on Saturday and continue acting as a focusing mechanism for diurnal convection. Instability will continue in the moderate to strong range with DCAPE again around 1000 J/KG and pwat values of 1.7 inches. Still expect afternoon and evening thunderstorms...with a better chance across the southern Midlands and CSRA. Strong winds and locally heavy rainfall be will the main threats. Hail potential will be lower Saturday as wet bulb zero heights will be higher. Saturday night through Sunday will see the upper level ridge build over the area with the ridge axis centered over the forecast area Sunday night. At the surface high pressure will move north of the area Saturday night and be located offshore of the Carolinas Sunday and Sunday night. With the remains of the front south of the area and high pressure pushing slightly drier air into the region Sunday and Sunday night...thunderstorm chances will be lower with slight chance over the northern Midlands and chance farther south. Temperatures will be in the low to mid 90s for afternoon highs with low to mid 70s for overnight lows. && .LONG TERM /MONDAY THROUGH FRIDAY/... Upper level ridge over the region Monday and Tuesday will be suppressed south and west Wednesday through Friday as an upper trough crosses the northeastern states. Surface high pressure over the western Atlantic will ridge into the southeastern states with a lee side trough over the Carolinas. Main concern for the first half of next week will be hot temperatures with highs in the mid to upper 90s and lows in the low to mid 70s. Should see heat indices between 100F and 110F. Scattered diurnal thunderstorms expected Monday through Wednesday. Several weak short waves moving through area on the east side of the upper ridge Thursday and Friday will increase the chance for showers and thunderstorms for the end of next week...as a frontal boundary drops south into the Mid Atlantic region. May see slight cooling by Friday but temperatures will remain above normal through the long term. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... VFR conditions expected outside of scattered diurnal convection. A weak front remains over the area, with scattered thunderstorms across the eastern Midlands. However, it is unlikely the terminals will see any more activity tonight. A 15 kt LLJ will inhibit widespread fog although cannot rule out a brief period of visibility restriction at fog prone OGB and AGS. Biggest uncertainty is at OGB where MAV and MET guidance hit it hard, but HRRR keeps conditions VFR. Due to persistence have left out of the forecast for now, but would not be surprised to see some visibility restriction by morning. Winds will be light and variable overnight. Easterly winds will pick up around 15Z with a scattered cumulus deck developing late morning to early afternoon Saturday. There will be another chance of scattered thunderstorms, but too early to know exactly where they will develop, so will not include mention yet. EXTENDED AVIATION OUTLOOK...There may be restrictions in stratus and fog during the early morning hours and also in mainly afternoon and evening thunderstorms through Wednesday. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
morning`s forecast discussion. Convection is slowly expanding on
coverage across the Pee Dee along/ahead of a weak, backdoor
cold front. Convection will gradually build/develop south with the front as a plethora of mesoscale boundaries interact with the sea breeze. The greatest coverage of tstms still looks to occur across the Charleston Tri-County area into Colleton County where the best juxtaposition of strong instability and low- level convergence will occur. Even at this hour, it is unclear how organized the approaching convection will become as any organization will be highly dependent on mesoscale processes given the weak shear profiles that are in place. Tstms will also be fighting quite bit of mid-level dry air. Conditions will be favorable for severe tstms with damaging winds, large hail and frequent cloud-to-ground lightning all being possible. The risk for severe weather looks greatest along/north of a Walterboro- Kiawah Island line. Farther south, instability drops off considerably, but still moderate for early summer. While an isolated severe tstm could still certainly pop farther south, especially along/south of the I-16 corridor there convection approaching from the south will be the most prevalent, the better instability and severe risk will remain confined to the far northern areas. For the overnight, pops will range from 60% across the Charleston Tri-County area and Colleton County to 30-40% across Southeast Georgia. Rain chances will steadily diminish by late evening with mostly dry conditions expected to prevail during the early morning hours Saturday as the backdoor cold front approaches the Savannah River. Lows will range from the lower 70s inland to the mid-upper 70s at the beaches. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... Saturday: A cold front will stall and weaken over southeast GA. Best moisture/instability will pool along this boundary and will support at least scattered showers/thunderstorms mainly during the afternoon/evening hours. Slow-moving thunderstorms could produce locally heavy rainfall and frequent cloud to ground lightning particularly along/south of the Savannah River. With expected Saturday afternoon instability not as strong as Friday afternoon, the associated severe potential should remain limited to the chance for a couple of stronger updrafts supporting isolated/brief damaging wind gusts. Sunday and Monday: A building upper ridge should support hotter temperatures and could limit coverage of mainly afternoon/evening sea breeze thunderstorms. The latest forecasts indicate slight chance/low chance PoPs during the afternoon/early evening hours. Also, the severe potential appears rather low. Meanwhile, heat index values of at least 100F are expected to increase in coverage especially away from the beaches, and we will assess the potential for higher heat indices/Heat Advisories, particularly starting early next week. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... Tuesday-Wednesday, an upper ridge will continue to produce a hot/humid pattern punctuated by typical afternoon/evening thunderstorms along the sea breeze. Then, global models indicate that the upper ridge will gradually retrograde/shift west as a broad upper trough over the northeast U.S./southeast Canada tries to push southward down the U.S. east coast Thursday and Friday. Expect rather typical isolated to scattered afternoon convection each day through Wednesday, with possibly an increase to at least scattered coverage during the afternoons by Thursday and Friday as upper heights lower, and better deep layer moisture potentially moves down from the north on the east side of the retrograding ridge. Guidance was producing likely PoPs most of the area by Thursday and Friday, but given the uncertainty, kept chance wording. Temperatures will continue above normal through the period. Highs in the lower to mid 90s, warmest inland, and lows generally in the lower to mid 70s, warmest near the coast. Outside any thunderstorms, daily afternoon heat indices should average at least 100-105F, and locally higher values could be realized. We will continue to assess the potential Heat Advisories for next week. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... A large cluster of storms has developed over the Berkeley/Dorchester County line, drifting to the SW. KCLX indicated that a well defined outflow has departed the storm cluster and appears to track to the SW at 25 kts. It appears that KCHS will observed a thunderstorm at the beginning of the Oz TAF, then should quickly dissipate with lingering stratiform rain. At KSAV, a few showers will drifting northward, but were quickly dissipating. After the convection, forecast soundings and MOS indicate that VFR conditions will prevail through the rest of the 0Z TAF period. The KSAV TAF will include a PROB30 for thunderstorms from 17Z-23Z. Extended Aviation Outlook: With a stationary/weakening front just south of the area, there exists the potential for later night/early morning stratus/fog, especially at KSAV early Sunday and Monday mornings. Also, the chance for mainly afternoon/evening thunderstorms and associated brief flight restrictions will be slightly greater around KSAV especially Saturday through Monday. Otherwise, expect VFR conditions much of the time. && .MARINE... Tonight: Convection approaching from the north along a backdoor cold front could pose a hazard to mariners late this afternoon into the evening hours. Saturday through Wednesday: Outside hazardous conditions within/near any thunderstorms, expect a typical early summer pattern to prevail. Aside from a brief wind shift to the northeast for a few hours Saturday, expect typical daily sea breeze/nocturnal S/SW winds and accompanying seas to remain below SCA levels through this period. && .TIDES/COASTAL FLOODING... Current data suggest tide levels will fall just short of shallow coastal flooding levels at Charleston Harbor. It could be close, but a Coastal Flood Advisory is not anticipated at this time. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...NED SHORT TERM... LONG TERM... AVIATION...NED MARINE... TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Duluth MN
1026 PM CDT Fri Jun 15 2018 .UPDATE... Issued at 1015 PM CDT Fri Jun 15 2018 Moved PoP maxima north towards the MN Arrowhead overnight. Included heavy rain tags and severe potential for Saturday morning. Latest SSEO guidance looks quite good - especially if you throw out the -12h runs and blend with the latest HRRR. All begin convection in the next hour or two and move it through the MN Arrowhead overnight. Eventually this will sag south towards WI by morning. It`ll be close, but the Duluth area may go largely unscathed until Saturday afternoon. UPDATE Issued at 636 PM CDT Fri Jun 15 2018 Updated aviation section below for the 00Z TAF update. && .SHORT TERM...(This evening through Saturday) Issued at 318 PM CDT Fri Jun 15 2018 An active weather pattern will continue across the Northland through the day Saturday, with the continued threat of severe weather and flooding through the weekend across portions of the Northland. The overall weather pattern has a longwave upper-level trough situated over the Pacific Northwest, which will remain in place. An upper-level ridge over the southeastern United States will help to block the flow aloft, and bring multiple shortwaves into the Northland. Moreover, a persistent low-level jet and warm, moist southerly flow will continue to enhance moisture transport, as evidenced by the 15.12z GFS, which shows increased theta-e advection moving into the region, which will help to fuel these storms. There should be plenty of instability available, with MUCAPE values overnight, with GFS, NAM, and GEM models all progging between 2 to 4 kJ/kg. The deep-layer shear appears to be modest through Saturday, with values generally between 25 to 35 knots, so some organized updrafts will be possible. Pwat values are progged to be between the 1.5" to 2.0" range, so plenty of moisture to rain out from these storms. Due to this favorable scenario, decided to issue a Flash Flood Watch for a good portion of the Northland through the weekend. The high-resolution model guidance has struggled to resolve today`s convection, so confidence in the forecast is below average, but it appears that there will be a general lull in the thunderstorm activity this evening before things ramp up overnight again. There is still some disagreements in the HRRR and NAMNest models regarding the areal coverage of the thunderstorms, so decided to broad-brush the PoPs for this evening and overnight. The HRRR wants to develop thunderstorms along an approaching surface cold front, and the NAMNest developing things along an approaching surface warm front, so lots of uncertainty with this scenario. Same story for Saturday, with the threat for showers and storms through the day. There is a Slight risk of severe weather over the southern half of our forecast area, with the main threats being large hail and damaging winds, along with flash flood potential. The best chances for severe thunderstorms will be in the afternoon and evening hours as instability will be maximized. MLCAPE values will be depended on prior convection, but values between 3 to 4 kJ/kg will be possible during the day. .LONG TERM...(Saturday night through Friday) Issued at 318 PM CDT Fri Jun 15 2018 A frontal boundary will remain parked over the area for Saturday night into Sunday. Multiple vort maxes will ride along this boundary bringing multiple rounds of storms. However, convective feedback continues to be an issue in terms of both timing and QPF. The best chance for severe storms Saturday evening and night look to be along and south of Highway 210 in Minnesota and into all of northwest Wisconsin. CAPE will be approaching 2000 J/kg depending on which model you look at in a rather moist environment. There continues to be a capping inversion in place with 700mb temps of 10-12C. This could lead to elevated storms which would reduce the severe threat somewhat. The low level jet is expected to ramp up during the evening which will help bring more moisture into the region. PWATs will already be around 2" and may increase to close to 2.5" overnight. This could further the threat for flooding considering many areas in northwest Wisconsin and parts of eastern Minnesota will already be saturated by earlier rainfall. Heading into Sunday, additional rounds of rainfall are expected as the frontal boundary slowly sags south. There could be another round of severe storms Sunday afternoon and evening across mainly northwest Wisconsin. PWATs will continue to run in excess of 2" keeping the threat for flooding in place. High pressure will then begin to build in on Monday with showers ending from northwest to southeast through the day. Dry conditions will then persist through the remainder of the period as high pressure remains in control. Temperatures will be near to slightly above normal for Monday before warming to 7-10 degrees above normal for Tuesday through Thursday. Dewpoints will be in the 50s during this time, so it should be fairly comfortable with any cooler temperatures being pinned along the immediate lakeshore. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 636 PM CDT Fri Jun 15 2018 VFR, but a lot of uncertainty heading through the night regarding convection and where it treks. If anything, there should be an uptick in activity Saturday morning which should bring about sub- VFR conditions - played the TAFs that way though intentionally left them vague as details can change rapidly. && .PRELIMINARY POINT TEMPS/POPS... DLH 59 77 62 76 / 50 70 70 60 INL 60 75 58 73 / 40 50 50 30 BRD 66 80 66 78 / 60 60 80 70 HYR 67 84 68 84 / 50 60 70 60 ASX 59 74 61 77 / 60 60 70 60 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Flash Flood Watch through Sunday morning for WIZ001>004-006>009. MN...Flash Flood Watch through Sunday morning for MNZ019-035>038. LS...None. && $$ UPDATE...Wolfe SHORT TERM...JTS LONG TERM...BJH AVIATION...Wolfe
Area Forecast Discussion
National Weather Service Goodland KS
553 PM MDT Fri Jun 15 2018 .SHORT TERM...(This afternoon through Saturday) Issued at 1129 AM MDT Fri Jun 15 2018 Latest upper air analysis shows southwest flow over the Plains. Within the flow multiple smaller scale troughs were analyzed by the RUC reanalysis. Towering cumulus clouds and light rainfall had developed over Central and Southwestern Nebraska where a corridor of strong isentropic lift had developed. These weak showers are not expected to last into the afternoon due to the isentropic lift weakening over the next hour or so. At the surface a low was positioned near Limon, CO, with a trough axis extending from the Limon area in an arc northward to near Benkelman, NE. A weak cold front had moved into the northwest part of the forecast area, which should provide some relief from the heat in Yuma County. The dry line was bowing east into NW KS. For the rest of the afternoon am not expecting any storms to form until close to 5 PM MT when upper level lift strengthens over the trough axis/dry line from roughly Gove to Leoti KS. If storms develop they will be isolated at best. Meanwhile isolated to scattered storms will move in from the west ahead of an upper level short wave trough, crossing into western Kit Carson/Cheyenne counties close to 6 PM MT. This evening the upper level short wave trough will deepen over the center of the forecast area as it moves east. Am expecting storm coverage to increase through mid evening as a result. During the latter half of the evening the short wave trough will begin filling. This will cause the short wave trough to turn and move to the northeast. Storm activity should be done around midnight if not before. During the evening, as the upper level short wave trough deepens, it will be co-located with the nose of the LLJ. This added lift will help increase storm activity. Close to midnight the nose of the LLJ will shift into Central Nebraska, causing storms to decline due to the loss of lift from the LLJ and the weakening short wave trough. The biggest threat for any storms this afternoon or early this evening will be wind gusts up to 65 MPH due to the high cloud bases. Deep layer shear is around 20 kts, while effective shear is 50-60 kts. While hail can`t be completely ruled out, confidence is on the low side that hail up to quarter size will occur due to the weak shear and hot temperatures. Even though the effective shear is quite strong, the storm activity should be behind the dry line which will limit how strong the storms become. At the surface the pressure gradient will remain tight, causing winds to be breezy and lows to be warmer than last night. Saturday the surface low will be shifted further north than today, closer to Denver as the upper level long wave trough deepens over the Pacific Northwest. This northward shift will move the hotter air mass further north, giving the forecast area a slight relief from the heat compared to today. .LONG TERM...(Saturday night through Friday) Issued at 245 PM MDT Fri Jun 15 2018 Main forecast concerns will be chances of thunderstorms through the period and the possibilities of severe thunderstorms and an increasing chance of locally heavy rainfall. Satellite showing an amplified pattern from the Pacific to along the east coast of North America. This pattern has remained unchanged with trough over the western portion of the North America and ridging over most of the eastern portion. Western trough is the process of deepening with more energy coming in from western Canada. In the southwest flow aloft both satellite and upper air analysis showing a connection to the subtropical moisture connection over Mexico and the desert southwest. Also the remnants of tropical storm Bud are in this flow. Also slow moving frontal boundary has sagged into the northwest portion of the area. Models were a little high on the jet segment nosing into the Desert Southwest. The Ecmwf was starting out a little better than the Gfs and Canadian. Saturday night...Some model difference on how far east to take thunderstorms. Steering flow is nearly from the south. Surface trough remains to our west with nearby front to our north through the night. Models keep main lift from mid level shortwave to the west of our area. Jet axis/any jet lift also remains to our west. Nam develops a cluster of storms directly to our south over southeast Colorado and southwest and brings it north. That is the most aggressive of any solution. Other output does bring some thunderstorms into the western and central portions of the area. That makes more sense given the reasoning above. With a more amplified pattern would expect the ridge to hold stronger and keep the main precipitation to our west. So at this time am fine with the slight chance to chance pops in my area during the night. However it is possible that this could be too far east. Sunday/Sunday night...Out of the first three days, this looks to be the most active time period. Ridging to the east and trough to west look to edge east a little. So mid level lift instability will also be further east and over our area. Jet axis/right rear quadrant gets close to or affects the western portion of the area late in the day. This moves across the area during the night. Also surface trough will edge further east with the front able to sag into the northwest portion of the area by late in the afternoon. Models are consistent and reasonable in developing thunderstorms in the northwest portion of the area where the deepest lift and best instability is at. Because of the mid level system moving through and convection along and behind the front will help shove the front through the area during the night. Jet axis/right rear quadrant gets close to or affects the western portion of the area late in the day. This moves across the area during the night. So expect a good chance of thunderstorms across the area late in the afternoon and especially during the night. Considering the instability, veering of winds, and a boundary parallel with the flow, would expect a decent chance of severe weather during this time. However, what may be a more widespread threat will be locally heavy rainfall that could cause flash flooding. Precipitable water values... This is 2 to 2.5 standard deviations above normal. Considering the PWs and flow parallel to the front, would expect training of thunderstorms that will be producing high rainfall rates. Will be ramping up these threats in the HWO. Monday...Main jet has moved to the east of the area. Surface ridging and drier, cooler, and more stable post frontal air mass will settle over the area. It will be much cooler from the previous three days and dry. Like the cooler blend temperatures which will be near 10 degrees cooler than on Sunday. Monday night through Friday... Beginning on Tuesday night the models come into major disagreement on how to handle the western closed low/troughing over the western half of North America. The 00z Ecmwf tends to hold onto the troughiness/closed low over the west the longest and the furthest west as well. The ensemble would tend to support the 00z Ecmwf the best. Also considering how amplified the pattern is, the slower and more amplified pattern looks the more likely solution. The PMDEPD mentions that the Ecmwf/Gefs and deterministic Ecmwf fit with this idea and have been the most consistent. However, the 12z Ecmwf has trended more like the Gfs and more north and east than before. The WPC surface progs for this period show the region remaining in the post frontal upslope region to the north of a stationary boundary. The WPC depiction shows that front slowing lifting back north on Thursday and Friday. The Gfs and Ecmwf also show the front near or over the southern/central portion of the area by the end of the period. So from a general/pattern recognition standpoint, this pattern is favorable for getting repeated episodes of locally heavy rainfall. The surface and mid level depiction from the deterministic/ensemble and WPC, this looking close to a Maddox type I flash flood setup. Precipitable water values look to stay in the 1 to 1.5 inch range. This is 1.5 to almost 2 standard deviations above normal. So heavy rainfall will be the main threat. However, there will be also be some severe weather during this time. So based on model differences, inconsistencies, and in general the models showing a wetter and cooler pattern, will be making no major changes to the forecaster blend temperatures and pops. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 536 PM MDT Fri Jun 15 2018 VFR conditions are expected at GLD and MCK through the 00Z TAF period. There will a period of isolated thunderstorms moving through the vicinity of GLD between 02-05Z and MCK between 03-06Z followed by a period of LLWS overnight that will diminish around 14Z as the low level inversion diminishes and gusty south winds begin mixing to the surface. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JTL LONG TERM...BULLER AVIATION...LOCKHART
Area Forecast Discussion
National Weather Service Lincoln IL
850 PM CDT Fri Jun 15 2018 .UPDATE... Issued at 850 PM CDT Fri Jun 15 2018 Mostly clear skies can be expected tonight as high pressure aloft brings subsidence to the area. A very warm air mass characterized by near 20 degrees C air at 700 mb has arrived in the area and will remain the next few days. Current dewpoints are in the mid 70s and will limit low temperatures to the low 70s overnight for a very warm night. Current forecast is on track with these features and no significant updates are needed this evening. && .SHORT TERM...(This evening through Saturday) ISSUED AT 317 PM CDT Fri Jun 15 2018 20z/3pm visible satellite imagery shows just a few patches of diurnal Cu across central Illinois this afternoon...as convective temperatures have not quite been achieved and a strengthening mid-level cap has prevented thunderstorm development. The closest convection has fired well to the south across southeast Missouri into western Kentucky where the cap is weaker. Latest run of the HRRR now keeps all isolated convection south of the KILX CWA late this afternoon into the early evening, so have gone with a dry forecast. Will be a warm and muggy night with overnight low temperatures remaining in the 70s. Abundant sunshine and light southwesterly winds will boost high temperatures into the lower to middle 90s on Saturday. With dewpoints hovering in the lower to middle 70s, heat index readings will peak from 100-105. Have therefore expanded the Heat Advisory to cover the entire CWA. .LONG TERM...(Saturday night through Friday) ISSUED AT 317 PM CDT Fri Jun 15 2018 Heat and humidity will continue both Sunday and Monday, with air temperatures in the middle 90s and peak heat index readings around 105 both days. The next chance for widespread convection will hold off until Monday night when a short-wave trough traversing southern Canada will begin to flatten the prevailing upper ridge and push a cold front southward into Illinois. Models are in fairly good agreement with the front arriving across the northern CWA Monday night, then sinking slowly southward into south-central Illinois during the day Tuesday. With ample deep- layer moisture in place, think showers and thunderstorms will be a good bet...particularly Tuesday and Tuesday night. After that, there is still some uncertainty as to how far south the front will drop before becoming parallel to the upper flow and stalling. The 12z ECMWF tends to hold the front slightly further north than the GFS, which could potentially keep rain chances alive across the southern CWA through Thursday. For now, will stick with the GFS...which maintains rain chances across the far south through Wednesday, then features dry/cooler weather for Thursday and Friday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 629 PM CDT Fri Jun 15 2018 VFR conditions expected for the next 24 hours across the central IL terminals. Cloud cover minimal with mainly just some low coverage of afternoon and evening cumulus around 5000-6000 ft AGL. Winds generally south 5-12 kts. && .ILX WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 7 PM CDT Monday for ILZ027>031-036>038- 040>057-061>063-066>068-071>073. && $$ UPDATE...37 SHORT TERM...Barnes LONG TERM...Barnes AVIATION...37
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
644 PM CDT Fri Jun 15 2018 .SHORT TERM...(This evening through Saturday) Issued at 336 PM CDT Fri Jun 15 2018 The primary forecast concerns through Saturday are temperatures and thunderstorm/severe potential. The large upper ridge over the Eastern U.S. keeps temps summer-like for Nebraska, while a stalled surface boundary will be the focus for convection. This evening and tonight... A lee side surface low associated with the front deepens across eastern CO while southeast winds/upslope flow lead to increased forcing and lift. Broad isentropic upglide with the front is underway, most notable around 315K. Convective- allowing guidance has varying degrees of activity developing in the panhandle and spreading northeast with this feature. The HRRR and HREF are the wettest, while the RAP and NAM-nest are more subdued. Went with a general blend approach, considering a ripe environment (ample instability of 3000+ j/kg MUCAPE from mesoanalysis and good moisture of 60s dew points), but a very warm layer around H7 (temps near 16C) are keeping things in check. As a strong LLJ develops tonight, the added convergence and shear should help fire off or maintain current convection. However, deep-layer shear remains limited (especially south of the front), so not expecting a widespread event. Temperature-wise, kept lows very mild in the 60s and even lower 70s central Neb due to aforementioned LLJ and H85 temps holding steady around 25C. Saturday... The low drifts northeast to the CO/KS/NE area while the front remains draped across the Sandhills. Looking at another hot and relatively humid day across SW and north central Neb with highs in the mid 90s, while far NW Neb stays in the lower 80s. A minimum in instability and layer of dry air in the mid levels should bring a lull in activity during the morning and early afternoon. Conditions ripen once again mid/late afternoon with convection initiating along/north of the front. Shear increases with strengthening H5 flow and the beginning of a coupled jet. Any storm that develops will likely quickly become strong or severe with large hail. .LONG TERM...(Saturday night through Friday) Issued at 336 PM CDT Fri Jun 15 2018 The latest model blend has marked up the 7-day storm total rainfall to 1 to 4 inches with highest totals across the eastern Panhandle. Precipitable water rises to 1.5 to 1.8 inches in the NAM, SREF, GFS and GEM models Saturday night and remains at those levels until Monday morning. Thereafter, the models show cold air aloft (-8C to - 9C ) at 500mb destabilizing the atmosphere daily in a post-frontal environment. This should support a chance of showers and thunderstorms Monday through Friday. Likely POPs are in place Saturday night through Sunday night with the potential for severe weather and locally heavy rainfall. The frontal boundary across swrn and ncntl Nebraska this afternoon lifts north into the Sandhills Saturday afternoon. This will be the focus for thunderstorms Saturday night. SPC outlooked areas along and north of the front for severe weather potential (Springview- Mullen-Sidney). Large hail and wind damage are the hazards with an isolated tornado threat. The initial hail/isolated tornado threat should evolve into lines and segments capable of wind damage. Following the WPC excessive rainfall guidance, the forecast includes a mention of heavy rainfall in the outlooked areas; Sheridan county Saturday night and most of wrn and ncntl Nebraska Sunday afternoon and Sunday night. The combination of an upper level low across the wrn U.S., a stalled surface front, a nocturnal low level jet and moisture from former hurricane "Bud" will be operating to produce locally heavy rainfall. Later forecasts may expand the areas for locally heavy rainfall as the NAM and GFS would suggest a threat as far south as Interstate 80 Saturday night. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 641 PM CDT Fri Jun 15 2018 Thunderstorms will move into the Nebraska Panhandle and southwest Nebraska late this evening with increasing clouds. Storms are expected to move through KVTN and KLBF between 6 and 7z. Clearing skies through the morning on Saturday. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Snively LONG TERM...CDC AVIATION...Power
Area Forecast Discussion
National Weather Service Louisville KY
704 PM EDT Fri Jun 15 2018 ...Updated Aviation Discussion... .Short Term...(This evening through Saturday) Issued at 300 PM EDT Fri Jun 15 2018 Mainly clear skies were observed across central Kentucky and southern Indiana this afternoon. A scattered cu field has developed over the SW counties (BG/Russellville). There`s still a substantial dewpoint gradient across the area, with around 60 in the Bluegrass and the low to mid 70s in the southwest. More widespread cu development has occurred in the moist atmosphere to our west and southwest. And with a remnant shortwave trough dropping through, scattered storms have popped up over western KY. This activity is expected to remain west of Bowling Green for the most part, but the HRRR suggests a couple storms could sneak into the SW forecast area. Tonight will be mainly clear with patchy light fog possible in the moist air in south-central Kentucky. We`ll see upper ridging continue to build over the weekend, and Saturday does look a bit hotter and slightly more humid than today. Peak heat indices are forecast to top out at 95-100 degrees along and west of I-65, where dewpoints will be highest. .Long Term...(Saturday night through Friday) Issued at 230 PM EDT Fri Jun 15 2018 ...Hot and Humid... Upper ridging is still on track for the weekend and into Monday, resulting in hot and humid conditions for the Ohio Valley. Sunday and Monday will be particularly unpleasant as dew points rise into the lower 70s and we see peak afternoon heat index readings in the mid 90s to around 100, especially west of I-65. While a stray storm or two is possible Sun/Mon, most areas will be dry under the upper ridge. The better chance for storms will come Tue-Wed as a boundary sinks south through the region. Depending on how much the ridge breaks down and how far south that boundary moves, south central KY may see continued precip chances through late week. Highs should drop back into the mid to upper 80s for the second half of the week. && .Aviation...(00Z TAF Issuance) Issued at 703 PM EDT Fri Jun 15 2018 Some very patchy fog may develop early tomorrow morning near KHNB/KBWG and could briefly reduce visibilities. Otherwise, VFR conditions are expected through the period as shower and storm activity remain north and west of the region. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Short Term...EBW Long Term...AMS Aviation...DM
Area Forecast Discussion...UPDATED
National Weather Service Mobile AL
959 PM CDT Fri Jun 15 2018 .DISCUSSION...See updated information for land areas below. && .UPDATE...Local radar trends have shown a general decrease in coverage going into the evening, but expect re-development and an increased coverage during the pre-dawn hours. With little movement of the the weak mid-level trof axis (shear zone) aligned over the deep south and plentiful deep layer moisture, forecasters have opted to make no change to the ongoing forecast with regard to probabilities of showers and storms. Some of the latest high resolution weather model guidance, notably the latest HRRR and 3KM NAM, suggests storms could become numerous along the Gulf coast and near shore waters late in the night. /10 && .PREV DISCUSSION... /issued 638 PM CDT Fri Jun 15 2018/ DISCUSSION...Updated for latest aviation discussion below. AVIATION... 00Z issuance...VFR conditions will prevail through much of the forecast for all TAF sites, but pilots may need to navigate around thunderstorms enroute through mid evening around the Mobile metro area. The shower and thunderstorm activity is expected to increase late tonight across the western Florida panhandle, so added TS to PNS starting at 05z, and added a TEMPO group from 06z to 10z for occasional periods of mid range MVFR ceilings and visibilities due to thunderstorms. Shower and thunderstorm activity is expected to increase again Saturday afternoon along the entire north central gulf coast region, so added a PROB30 group from 18z to 24z for all TAF sites for now. Will monitor the evening activity and update as needed. /22 PREV DISCUSSION... /issued 352 PM CDT Fri Jun 15 2018/ NEAR TERM /Now Through Saturday/...A weak mid level circulation continues to spin in the vicinity of southwest AL this afternoon, while an associated weak mid level trough axis extends across much of our region. A very moist airmass remains in place across our forecast area under this feature this afternoon, with precipitable water values estimated between 2" and 2.2" across the region. The earlier convection near the coast has diminished as of 3 PM, but new convective development is occurring over portions of southeast MS and interior southwest AL where more sun has allowed for destabilization on the northwestern periphery of the mid level circulation. This convection will be need to be monitored closely as it moves into Choctaw, Clarke, Wilcox and potentially Washington counties this afternoon, as this portion of the region has received heavy rainfall amounts on the order of 2" to 5" since Thursday morning. Additional heavy rainfall could result in at least minor flooding of low lying areas, but if heavier rainfall rates materialize with some of these stronger storms, we cannot entirely rule out very localized flash flooding. Convection over the interior may tend to move/develop southwestward into portions of southeast MS and farther south over southwest and south central AL this evening per HRRR and WRF-ARW trends. This activity may weaken with loss of daytime heating, with a potential lull in convection during the mid to late evening hours. The weak mid level circulation may become less discernible with time late tonight into Saturday, but the associated plume of deep moisture will continue to extend across our forecast area through Saturday afternoon. Additional scattered to numerous showers and thunderstorms may re-develop overnight into early Saturday morning, particularly near coastal portions of the western FL panhandle and southwest AL, while other isolated to scattered showers and storms remain possible farther inland. We have trended the forecast close in line with guidance from WPC, WRF-ARW and HRRR, which favors higher QPF and POPs near the southwest AL and western FL coast (50- 60% coverage) between 06-12z, with values tapering farther inland. Scattered to numerous showers and storms should develop inland with time Saturday morning into afternoon. Plentiful deep moisture will support a continued potential for locally heavy rainfall through Saturday afternoon. Considering the heavy rains that have fallen over a good portion of the area the past 24-48 hours, will keep a limited potential of flooding highlighted in graphics and the HWO through Saturday. No significant changes to temperatures were made. /21 SHORT TERM /Saturday night Through Monday night/...With the mid- level disturbance exiting off to the northeast, we return to a more typical summerlike pattern through the short term in terms of shower and thunderstorm coverage. Expect chance PoPs (30-40%) and scattered activity to develop both Sunday and Monday, primarily during afternoon hours as it will be largely driven by daytime heating. Localized heavy rainfall and frequent lightning will remain the primary threats, though stronger storms will be capable of producing gusty winds and perhaps some small hail as well. High temps reach the upper 80s to around 90 each afternoon and lows remain in the low to mid 70s each night. /49 LONG TERM /Tuesday Through Friday/...The weather pattern remains unsettled through next week as weak low pressure in the upper levels persists over the northern Gulf coast region. The combination of daytime heating and lingering deep-layer moisture (PWATs at or above 1.75 inches) should support scattered convection each afternoon and evening, with activity tapering off each night. Thus, have opted to maintain our diurnal pattern of chance/slight chance PoPs each day/night, respectively, throughout next week. Temperatures to remain near seasonal, with highs in the upper 80s to lower 90s and lows in the lower to mid 70s. /49 MARINE...Area marine observations indicate a light westerly flow pattern prevalent this afternoon away from earlier outflow boundaries. A light to occasionally moderate southwesterly to southerly flow should develop tonight into Saturday as surface ridging shifts over the eastern Seaboard and FL peninsula. Light southeasterly flow then looks to return Sunday into early next week as ridging builds westward over the north central Gulf and Gulf Coast states. /21 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...None. FL...None. MS...None. GM...None. && $$ This product is also available on the web at: http://weather.gov/mob
Area Forecast Discussion
National Weather Service Marquette MI
750 PM EDT Fri Jun 15 2018 .SHORT TERM...(This evening through Saturday) Issued at 447 PM EDT FRI JUN 15 2018 WV imagery and RAP analysis indicated a mid/upper level trough over the wrn CONUS and a ridge from the lower MS valley to the wrn Great Lakes resulting in sw flow from the plains to wrn Lake Superior. At the surface, a trough extended from ne Manitoba into wrn MN with a warm front from w cntrl MN to sw WI. The 1000-850mb theta-e ridge through the upper MS valley along with with 25-35 knot 850 mb winds provided plenty of instability with MUCAPE values to 3k J/Kg to support clusters of shra/tsra near the top of the ridge from nw WI around KIWD. The heaviest rain earlier today also remained near far wrn Upper Michigan where rainfall reports/estimates were in the 2-4 inch range. The brief bout of strong sse winds behind the initial area of convection due to a wake low/gravity wave have also diminished. Tonight, into this evening, expect that the shra/tsra will remain continue to slide ese from nw WI given the alignment of the low level jet inflow and position of the CAPE gradient. By the overnight, there is more uncertainty as additional tsra development is likely over nrn MN to wrn Lake Superior as a shortwave trough moving out of the Dakotas approaches the region and the low level jet strengthens. Confidence in the location of tsra development and eventual path is still low but most short-range model guidance suggests that wrn Upper Michigan will again see the greater tsra chances. With very high PWAT values in the 1.5-2.0 inch range remaining over the region, the main hazard will again be heavy rain with the potential for some small hail and higher wind gusts with the strongest tsra clusters. A Flash Flood Watch was issued for the far west where the ground is already saturated and stream levels are high and where the threat of additional heavy rainfall is also significant. Saturday, confidence in any details with convection development remains below average as the impacts of convection earlier in day (the amount of cloud cover/instability and outflow boundaries) will have a significant influence on later evolution. Shra/tsra chances will linger through the entire day even though most of the day may not see any pcpn. High temps may also be reduced by leftover clouds/pcpn. Nevertheless, very warm and humid conditions are expected with highs to the lower 80s and dewpoints into the upper 60s. .LONG TERM...(Saturday night through Friday) Issued at 457 PM EDT FRI JUN 15 2018 Models suggest that a slowly progressive northern stream pattern will prevail into next week. This will leave Upper Michigan on the periphery of the mid/upper level srn stream ridge through the weekend until a shortwave trough moving through nrn Ontario helps push the sfc frontal boundary to the south. Mainly nw flow will then prevail through the rest of the week as a trough develops over ern Canada. Saturday night through Sunday night, the potential for additional rounds of more widespread shra/tsra is expected as the sfc boundary sags into the region, especially later Sunday into Sunday night. One or more shortwaves or sfc waves may also enhance the possibility for heavy rain as high PWATS remain over the region. Monday, the frontal boundary is expected to sag to the south of Upper Michigan, taking the higher shra/tsra chances with it as rain should diminish from north to south. Clouds and lingering rain will limit high temps to the 60s to lower 70s. Tue-Fri, drier air will move back into the region as sfc high pres builds in from the plains and s cntrl Canada dropping dewpoints back into the 40s. Temps will remain near or slightly above normal. There may be a chance for some lighter showers with any weak clipper shrtwvs that brush the area. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 749 PM EDT FRI JUN 15 2018 Upslope southerly winds in the wake of earlier pcpn may support ocnl low MVFR cigs at KSAW this evening. In addition, recent development of upslope easterly winds at KCMX could lead to IFR cigs at times, but confidence is low for that to occur. Otherwise, VFR conditions should generally prevail at KIWD/KCMX/KSAW thru this fcst period. However, clusters of shra/tsra will be roaming the Upper Lakes region and may impact the terminals at times thru Sat. Confidence in location and timing of these shra/tsra are low, but it appears late tonight and Sat morning may be a time period where the terminals may be impacted. If so, MVFR/IFR conditions will be possible. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 458 PM EDT FRI JUN 15 2018 Winds will generally remain between 10 to 20 knots through the end of the weekend. However, additional areas of showers and thunderstorms through Sunday night may result in some very gusty erratic winds, maybe even as high as 35 knots for a brief period. Winds will relax into early next week with speeds generally around or less than 15 knots, with perhaps a brief uptick towards 20 knots on Monday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Flash Flood Watch through Saturday morning for MIZ002-009. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...JLB AVIATION...Rolfson MARINE...JLB
Area Forecast Discussion
National Weather Service Paducah KY
444 PM CDT Fri Jun 15 2018 .UPDATE... Issued at 441 PM CDT Fri Jun 15 2018 Updated Aviation discussion for 00Z TAF Issuance. && .SHORT TERM...(Tonight through Sunday night) Issued at 241 PM CDT Fri Jun 15 2018 Main forecast story in the short term continues to lie with the building heat as we head into and through the weekend. Large scale mid/upper level ridge will align itself along much of the MS and lower OH River Valleys during most of the short term. Surface dew points in the 70-75 range will combine with afternoon temps into the lower/mid 90s to produce heat index values from 100 to 105 or so, esp much of se MO/srn IL and far wrn KY. Beginning with yesterday (Thu), this could make 4 straight days of 100-105 heat indices in much of the that area. Therefore, will go ahead and issue a heat advisory for Sat/Sun with this forecast package for the aformentioned regions. Areas outside of the heat advisory, such as sw IN and much of the Pennyrile of wrn KY are expected to stay closer to 100 degree heat indices, so plan to cover those regions with a special weather statement for now. The hottest afternoon could end up being Sunday, so an expansion of the heat advisory a bit farther east may be needed with time. As far as precip chances are concerned, it appears that a weakness in the pronounced mid level pressure ridge will sick around over/near wrn KY most of the weekend. A modest moisture swath associated with this feature may be enough to trigger more in the way of isolated thunderstorms both Saturday and Sunday during peak heating hours. Though most locations should stay rainfree and hot this weekend, will need to monitor any storms that do form for gusty winds and small hail due to the extreme instabilities expected. Outflow boundary interaction(s) would then be the main focus for any additional storm development. .LONG TERM...(Monday through Friday) Issued at 241 PM CDT Fri Jun 15 2018 Guidance continues to hint that the upper level ridge will break down and push off to our southeast next week. This should allow a cold front to progress southward into the region at some point. Right now the timing looks to be mainly Tuesday night into Wednesday, with PoPs increasing ahead of it on Tuesday, especially in the north. Given the upper level pattern, it will be hard to rule out precipitation chances for at least some portion of the area during most periods in the extended. An increase in mid level flow expected by mid to late week, may help to enhance the overall coverage of showers and thunderstorms. The 12z ECMWF hints at this, while the GFS actually brings down surface high pressure from the north which would dry out much of the area for Thursday and Friday. Thus lower confidence later in the extended period. Some additional cloud cover combined with 500 mb heights lowering, should allow temperatures to lower somewhat next week. However, above normal readings look to continue, with highs generally close to 90 degrees through the week. With dewpoints remaining in the lower 70s much of the period, heat index values are expected to peak in the mid 90s to around 100 most days. && .AVIATION... Issued at 441 PM CDT Fri Jun 15 2018 Latest HRRR keeps pm convection active near our southern terminals (KCGI/KPAH) til 03Z, then diminishes all activity afterward. Excepting vicinity or categorical mentions there til then, should otherwise return to VFR/clearing skies with another late night potential for MVFR fog (all terminals) toward daybreak. Diurnal cu tmrw should genesis in the 4-5K FT AGL range. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...Heat Advisory from 11 AM Saturday to 7 PM CDT Sunday for ILZ075>078-080>094. MO...Heat Advisory from 11 AM Saturday to 7 PM CDT Sunday for MOZ076- 086-087-108>112-114. IN...None. KY...Heat Advisory from 11 AM Saturday to 7 PM CDT Sunday for KYZ001>011. && $$
Area Forecast Discussion
National Weather Service Tucson AZ
855 PM MST Fri Jun 15 2018 .SYNOPSIS...Widespread rain with a few embedded thunderstorms will continue as remnants of Bud pass nearby tonight and early Saturday. Expect cooler temperatures again Saturday followed by dry conditions Sunday and the return of June heat early next week. && .DISCUSSION...Widespread rain with a few embedded thunderstorms will continue overnight into early Saturday. Latest models keep the focus on areas south and east of Tucson for picking up the most rainfall through Saturday morning. Latest HRRR solution showed most of the rain shifting farther eastward by 13Z Saturday. This will result in a brief lull before showers and thunderstorms redevelop with the daytime heating. The current forecast appeared to handle this trend well, so no updates necessary late this evening. Refer to the additional sections for more details. && .AVIATION...Valid through 17/06Z. Scattered showers and a few embedded thunderstorms will continue through the period. Clouds BKN-OVC at 10-15k ft AGL with lower decks to 5-8k ft AGL near showers through Saturday. SFC winds generally WLY/NWLY at 12-15 kts, with gusts to 35 kts possible near any -TSRA. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Showers and a few thunderstorms will continue through tonight and early Saturday. The heaviest rainfall amounts are likely east and south of Tucson. Recent burn scars could experience increased runoff possibly leading to some flooding, particularly the Frye and Lizard fire burn scars. Conditions gradually improve from west to east throughout the day on Saturday, followed by dry conditions Sunday and a warming trend next week. && .CLIMATE...The 6th longest dry streak on record for Tucson came to an end today with the first measurable rain at the airport since February 28th. Even though the summer thunderstorm season begins today, most area rainfall records for June 15th are quite low, so expect lots of record rainfall reports today and Saturday. Some areas may also be close to setting low high temperatures and warm minimums for June 15th. && .PREV DISCUSSION...On Saturday, a brief period of clearing behind Bud will allow for better solar insolation compared to today. The upper low west of San Diego will move into southwest Arizona Saturday afternoon, with stronger upper level dynamics working on residual moisture to create another round of scattered showers and thunderstorms. Localized heavy rain and strong to severe storms are possible as cooler air aloft pushes across the area on southwesterly flow. The precipitation threat will then end from west to east late Saturday evening into early Sunday morning. With the aforementioned upper low ejecting northeastward into New Mexico on Sunday, noticeably drier air will settle in across the region. This transition will be complete with clear to mostly clear skies and the return of near triple digit heat by Monday. Dry conditions and a warming trend will continue through Friday of next week as the Four Corners high typical of our monsoon struggles to set up, and instead tries to consolidate west of our area keeping moisture to the east. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ PREV DISCUSSION/AVIATION/FIRE WEATHER...ECC/JP Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson