Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/17/18

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
554 PM MDT Mon Jul 16 2018 .AVIATION... 00Z TAF CYCLE Scattered convection will continue through approximately 17/06Z before gradually dissipating. Storms will produce brief MVFR/IFR conditions and mountain obscurations. Drier air will move in Tuesday, limiting afternoon and evening thunderstorm coverage to the northwest third of the state, especially mountains. 33 && .PREV DISCUSSION...247 PM MDT Mon Jul 16 2018... .SYNOPSIS... High terrain thunderstorm activity has sprung up again this afternoon. Storms will gradually move westward expanding over lower elevations of central and western New Mexico. Storms over eastern New Mexico will be more isolated and erratic in their motions. Any storm will be capable of producing localized heavy rainfall and flash flooding. Storm coverage trends down tomorrow through the rest of the week, being more confined to the higher terrain. Highs will also trend up as high pressure builds over the state, with 100s popping up over eastern New Mexico by Wednesday. && .DISCUSSION... Another day, another round of afternoon storms forming over the high terrain of central and western NM. A few storms have also formed along a sfc bdry from Quay down to Roosevelt Counties. An easterly wave is currently located over the southern periphery of NM, setting up stronger westerly flow there, allowing storms to move along at a somewhat decent pace. Flash flooding still remains a concern for those areas having received rainfall in recent days. Storm motion is much slower over the northern mtns of the state where localized heavy rainfall and flash flooding are the main concerns again. Have kept the Flash Flood Watch going for portions of central and western NM, except the northern Sacramento Mtns where dry mid- level air behind the easterly wave is working to inhibit storm formation so far. HREF and HRRR are also not gun-ho not showing much of anything forming there through the rest of today. Another outflow enhanced frontal push from CO into northeast NM could keep storms going a bit longer tonight for the northeast plains. Otherwise, expecting storms to taper off this evening into Tuesday morning. High pressure begins to build over the state Tuesday, with the drier mid-level air behind the easterly wave pushing over southwest NM. This will limit most of tomorrow`s storm activity to the northern mtns. The ridge continues to build over the Four Corners mid-late this week, with storm coverage trending down and high temperatures trending up. Models have backed off quite noticeably from yesterday, and are limiting afternoon convection to the higher terrain. Although rainfall footprints are expected to be less, the threat for locally heavy rainfall and flash flooding over high terrain burn scars will remain. Highs across the state will be several degrees above average by Wednesday, with 100s popping up over eastern NM. The ridge looks to slide more squarely over NM this weekend, keeping storms limited to the higher terrain in the afternoons. Long range, the GFS and ECMWF differ handling an embedded trough along the northern periphery of the ridge. The GFS has it a bit stronger, bringing more of a NW flow over northern NM. This would favor a backdoor front sliding into eastern NM, increasing storm coverage there early next week. Will have to monitor this as we get closer. 24 && .FIRE WEATHER... An easterly wave will move to the west across southern NM this afternoon, while a ridge of strong upper level high pressure in the Great Basin builds eastward across western CO and northwest NM. The mid and upper level flow between these systems will be east at around 10 knots across central NM, and light winds aloft will prevail across northern NM under the influence of the upper level ridge. Winds near the surface this afternoon and evening will be light. Deep layer moisture will remain across the region this afternoon and evening, and scattered to locally numerous showers and thunderstorms will develop with the greatest density of activity across the higher terrain of northern and western NM. Flash flooding will be possible this afternoon and evening in portions of northern and western NM. Ventilation rates will be fair to good across most of the region this afternoon, but will be poor to fair in portions of northern and western NM. The upper level ridge will expand over northern and central NM Tuesday, as drier mid level air spreads westward across eastern and south central NM. Warmer and drier air aloft will decrease shower and thunderstorm activity in eastern and south central NM Tuesday afternoon and evening. Despite warming aloft, scattered showers and thunderstorms will develop across northern and western NM Tuesday afternoon and evening with the continued threat of flash flooding due to slow storm motion. Weak surface high pressure in TX Tuesday will produce light south winds across western and central NM and south winds 10 to 15 mph across the eastern plains. Ventilation rates in north central and western NM Tuesday will be poor to fair with fair to good conditions elsewhere. There will continue to be a decrease in shower and thunderstorm activity across most of the region Wednesday, as the large ridge to the west becomes stronger and builds farther east across NM. The exception will be in the northeast plains and adjacent highlands, where a backdoor cold front is expected to increase activity Wednesday afternoon and evening. The strong ridge will remain over NM Thursday with less coverage of showers and thunderstorms. Little change is expected Friday, except a backdoor cold front may increase shower and thunderstorm activity from the northeast and east central plains west to the central mountains. The strong upper high will shift eastward Saturday and Sunday with recycled moisture producing isolated to scattered showers and thunderstorms. Temperatures will be above normal Wednesday through Sunday with minimum relative humidity each day from the upper teens to lower 30s. 28 && .ABQ WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through late tonight for the following zones... NMZ503>506-508-510>515-521. && $$ 24
Area Forecast Discussion
National Weather Service Caribou ME
1150 PM EDT Mon Jul 16 2018 .SYNOPSIS... A strong cold front will approach the region from the west early Tuesday then cross the region later Tuesday through Tuesday night. High pressure will build across the region Wednesday into Thursday. && .NEAR TERM /THROUGH TUESDAY/... 1135 pm Update... Temperatures at this hour were ranging from the low to mid 60s across downeast in areas of fog but in the mild lower 70s across the northern half of the forecast area. Have adjusted the forecast based on current conditions. Did back off a bit on the chance of showers overnight based on latest HRRR and current radar trends. Prev discussion blo... A southerly flow will emerge this evening and through the night. This flow will advect a broad area of fog and stratus from the Gulf of Maine northward to cover most of the forecast area by later tonight. Fog will be most likely towards the coast and in higher terrain areas, but could extend over the southern half of the forecast area by daybreak Tuesday. Stratus will definitely cover the entire area by later tonight. The clouds and continued moisture advection will limit lows tonight to the low to mid 60s. The low clouds remain a big part of the story on Tuesday as they`ll limit high temperatures and development of surface-based instability. As a result, will not include any enhanced wording for winds or hail in spite of the SPC marginal risk. Heavy rainfall remains the significant concern. There is some elevated instability that will cross the southern half of the area Tuesday morning into early afternoon. Some storms could fire from an H850 thermal ridge and there is a strong H850 LLJ exit region on the back edge of this elevated instability area. Will mention scattered thunderstorms with heavy rainfall in response. Both surface-based and elevated convection are unimpressive in the afternoon when PWATs and the deep warm cloud increase ahead of the cold front. Dew points will likely be just above 70F ahead of the cold front, an event that occurs very infrequently here. The abundant moisture, warm cloud depth, strong LLJ, precipitation efficiency and potential for training cells leads to continuing mention of heavy rainfall in the northern and western zones Tuesday afternoon. All of the area will likely receive a much-needed half inch to an inch of rainfall, but the area most likely to receive greater amounts appears to be towards the Moosehead Lake region. The combination of terrain in Piscataquis County and rainfall rates locally reaching 1 to 2 inches in 3 hours will make this area worthy of close watch later tomorrow. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... A cold front will cross the region Tuesday night, reaching the Downeast coast late. Precipitable water values of around 2.00 inches are expected in advance of the front. With the abundant moisture and possible training showers/thunderstorms, could still have a chance of locally heavy rain in advance of the front Tuesday night. Shower/thunderstorm chances will diminish in the wake of the front. The front will exit across the Gulf of Maine Wednesday, while high pressure begins to build toward the region. Could still have a chance of showers Downeast early Wednesday with the exiting front, with decreasing clouds during the afternoon. Across northern and central portions of the forecast area, expect partly/mostly cloudy skies early Wednesday with decreasing clouds during the afternoon. High pressure then builds across the region Wednesday night through Thursday with mostly clear skies. Temperatures will be at near normal, to slightly above normal, levels Wednesday/Thursday. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... High pressure will remain across the region Friday into Saturday, then begin to exit across the Maritimes later Saturday. Generally expect mostly clear skies Friday/Saturday. The return flow around exiting high pressure will bring increasing moisture Sunday into Monday with increasing shower chances. Temperatures will remain at near normal, to slightly above normal, levels Friday through Monday. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... NEAR TERM: 1135 Update... VLIFR at this hour KBGR/KBHB in low clouds and areas of fog. VFR was occurring at the northern terminals but expect conditions to deteriorate to IFR/LIFR by daybreak in low clouds and patch fog. LIFR at BHB into Tue afternoon. Remaining terminals will see IFR restrictions, though showers may raise conditions to MVFR at some point during the afternoon. However, embedded tstms with locally heavy rainfall expected may keep IFR restrictions in place through most of the day. SHORT TERM: Generally expect MVFR/IFR conditions across northern areas through the early morning hours Wednesday, with improving conditions late. MVFR to LIFR conditions are expected Downeast Tuesday night. Showers, with a slight chance of thunderstorms along with locally heavy rain, are expected in advance of the cold front Tuesday night. MVFR/IFR conditions are expected Downeast early Wednesday, with VFR conditions developing during the afternoon. VFR conditions are expected across northern areas Wednesday. VFR conditions are expected across the entire region Wednesday night into Saturday. && .MARINE... NEAR TERM: Fog continues through Tuesday. Winds and seas will pick up ahead of cold front later Tuesday, but the stability of the situation does not support an SCA due to winds. Long period south swell could reach nearly 5 ft by late Tuesday. SHORT TERM: Generally expect conditions to remain below small craft advisory levels Tuesday night through Thursday. However, conditions could approach small craft advisory levels early Tuesday night. Visibilities will be be reduced in showers and fog, along with a slight chance of thunderstorms, Tuesday night. Showers will persist early Wednesday. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...Dense Fog Advisory until 8 AM EDT Tuesday for MEZ029-030. MARINE...None. && $$ Near Term...Duda Short Term...Norcross Long Term...Norcross Aviation...Duda/Norcross Marine...Duda/Norcross
Area Forecast Discussion
National Weather Service Cheyenne WY
206 PM MDT Mon Jul 16 2018 .SHORT TERM...(This evening through Wednesday night) Issued at 200 PM MDT Mon Jul 16 2018 Convection has been confined mainly to the Snowy Range early this afternoon with some weak showers persisting farther north. Satellite showed an approaching shortwave with some convection developing over western Wyoming. Expect showers and storms to spread into the western parts of the CWA by late this afternoon and move over the plains through much of this evening. Best instability looks to be over northern parts of the CWA and expect this area to get the strongest storms, mainly this evening as suggested by the HRRR and NAM. Showers and storms likely to persist through tonight over the Nebraska Panhandle as the shortwave passes by. Similar pattern across the area Tuesday with the next shortwave likely to kick off another round of convection especially over the plains. Some strong to severe storms possible again with instabilities from 1500-2500 J/kg progged over the plains Tuesday afternoon and evening. Drier air then moves into the area Tuesday night with monsoonal moisture being shunted to the south with a warm and dry day Weds. .LONG TERM...(Thursday through Monday) Issued at 200 PM MDT Mon Jul 16 2018 Center of upper ridge west of the Four Corners will gradually drift east and amplify over the Rockies and High Plains through Saturday. Upper shortwave trough tracking east across the Northern Rockies and Plains will suppress the ridge to the south Sunday and Monday. After a rather warm Thursday, a dry frontal passage late Thursday will bring slightly cooler temperatures Friday. A warm up returns Saturday as 700mb temperatures rise to near 20 deg Celsius. A lee surface trough sets up across the high plains Saturday afternoon, which may focus isolated late day convection, as well as over the Snowy/Sierra Madre mountains. Another front pushes southeast across the CWA Sunday afternoon, with focus for widely scattered convection along and south of I-80 in southeast WY. High temperatures Monday will be closer to seasonal normals with highs in the 80s. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday morning) Issued at 1147 AM MDT Mon Jul 16 2018 Residual MVFR CIG at KSNY will become VFR by 20Z. Few SHRA/TS have formed during the morning along a weak outflow boundary across east- central WY. Convection will redevelop over the higher terrain of southeast WY by mid-afternoon, and intensify while spreading east during the late afternoon and evening. With the exception of KRWL. have VCTS after 21Z at KLAR and KCYS, with VCTS or prevailing -TSRA for the NE Panhandle after 06Z. Isolated strong/severe TSRA with hail, strong winds and turbulence will be possible east of the Laramie Range after 22Z. && .FIRE WEATHER... Issued at 200 PM MDT Mon Jul 16 2018 Fire weather concerns should stay fairly low through the week with warm conditions continuing. There will be scattered to numerous showers and thunderstorms into this evening, and again on Tuesday as a couple disturbances pass across the region. Drier conditions are then expected across the area Wednesday through Friday as monsoonal moisture is cut off for a time. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...RE LONG TERM...MAJ AVIATION...MAJ FIRE WEATHER...RE
Area Forecast Discussion
National Weather Service Wilmington NC
933 PM EDT Mon Jul 16 2018 .SYNOPSIS... Moisture will continue to increase ahead of a cold front that will arrive Tuesday night. After a break in the showers around Thursday, the front and its moisture will return on Friday and linger over the weekend. && .NEAR TERM /THROUGH TUESDAY/... As of 930 PM Monday...One cluster of thunderstorms that has recently developed across western Williamsburg County apparently didn`t get the memo that it was supposed to wait a few more hours. The latest HRRR shows some showers developing across this area but not until 03Z/11 PM EDT. Convection is still anticipated to be most numerous near the coast and offshore overnight, following better low-level instability near the 85-degree ocean water. Forecast PoPs through 12Z/800 AM EDT range from 20-30 percent along the I-95 corridor to 50-70 percent along the coast, highest in the Myrtle Beach to Cape Fear/Bald Head Island corridor and offshore. Severe weather is not expected overnight, but locally heavy rainfall could certainly develop given increasing precipitable water values, slow cell motion, and nearly 13,000 feet between the LFC and the freezing level supporting efficient warm-cloud coalescence processes. Discussion from 700 PM follows... Changes with the near-term portion of the forecast are primarily concerned with pushing back the beginning of PoPs by several hours based on latest radar and HRRR/GFS model trends. It still appears reasonable for showers to begin blossoming along the SC coast and just offshore around midnight, spreading northeastward toward Cape Fear before daybreak. Weak lapse rates and a dry mid-level airmass are currently impediments to convection, however as southwesterly 850-500 mb winds increase overnight moisture should increase from the west where precipitable water values are near 2.2 inches across western South Carolina. Interior portions of the eastern Carolinas don`t appear quite as likely to receive measurable rain overnight due to relatively stable thermodynamic conditions and I`ve trimmed PoPs back to 20-30 percent here. No changes have been made to overnight low temp forecasts, still anticipated to reach the lower to mid 70s. -TRA Discussion from 300 PM follows... There will be decent mid to upper level support and moisture returning as a shortwave rotates through the Southeast, over our local forecast area tonight and deep SW flow develops. The convection upstream this afternoon, as seen by radar, has been enhanced by shortwave and deeper level moisture. Expect this to reach into our area through this evening and into tonight. Clouds have kept heating slightly moderated so far today with temps reaching into the 80s and the best shortwave energy has been delayed keeping a very moist column tonight with smaller CAPE values showing mainly elevated instability and still some warmer air in the mid levels, but heading into Tues morning, instability will increase with a deep SW flow and pcp water values up near 2.3 inches. Convection will be especially enhanced over the nocturnally favored adjacent waters overnight as the shortwave energy rotates around from the S-SW. Therefore kept best chc of pcp along the coast overnight into early Tues. The intensity of convection should diminish some as heating of the day cuts off, but expect clouds and pcp through the period. WPC shows a marginal risk for excessive rainfall across the Eastern Carolinas with a slight risk right along the tip of Cape Fear and just north. The column dries somewhat through Tues aftn as flow veers to the W-NE as shortwave reaches the coast, but still shows 1.9 inches of pcp water. May see a lull in convection at this time, but kicks back up again later Tues ahead of an approaching cold front. Overall, expect clouds and increased chc of pcp through much of the period. Winds will remain light through much of tonight, but will increase out of the SW on Tues as gradient tightens between Bermuda High to the east and approaching cold front. Expect some stronger storms possible as moisture pools and heights fall ahead of cold front through later on Tues. Clouds and pcp will moderate the temps through the period, but overall expect a humid air mass in place through the period with less of a diurnal swing with overnight lows in the 70s and mid 80s to around 90 for highs on Tues. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 300 PM...Moisture will surge ahead of a mid-level trough and cold front that will approach the forecast area Tuesday night. A deep layer of synoptic lift ahead of the front, along with precipitable water values of up to 2.3 inches will lead to numerous showers with potential for thunder Tuesday night. WPC has drawn a slight risk of excessive rainfall across the Cape Fear region, and a marginal risk elsewhere across the forecast area, through the Tuesday night time frame. The front will make it into the northwestern tier of the CWA by 12Z Wednesday, then slowly make its way through Williamsburg and Georgetown counties Wednesday evening. Cloud cover Wednesday will limit instability to a point, however areal coverage of showers and thunderstorms should increase with daytime heating. PoPs will decrease Wednesday night as significant drying occurs in the 700-300 mb layer. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 300 PM Monday...Frontal moisture sinks far enough south and east that most of the area may see a break in the otherwise rain- laden week. Some light rain could linger near the coast due to its proximity to the stalled front. Mid level trough in the Great Lakes starts reloading on Friday and the front and its associated moisture/rain should return (quite heavily according to the ECMWF, more tempered and only coastal according to GFS-the former now the favored solution). The confluent/digging nature of this upper wave will keep us in the deep moisture as well as the warm sector of the surface system. Rain chances will persist as will the chance for some appreciable rainfall amounts. Despite the extensive cloud cover for most of the period temperature guidance is showing temperature deviations from climatology as being minimal. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 00Z...Time height shows fairly dry air aloft at present, with no convection expected this evening. After midnight, deep moisture starts to advect in from the southwest, with the atmosphere becoming saturated all the way to 400 mb. Cape will only be moderate on Tuesday due to the cloud cover, and thunder will be limited to the afternoon hours. Showers are a good bet throughout the day. Visibilities could go below 2 miles briefly in the heavier convection with high precipitable water values. Ceilings will likely bounce around, but should be predominately MVFR. Southwest flow through the forecast period. Extended Outlook...Occasional MVFR to IFR conditions due to scattered to numerous showers and TSTMs. && .MARINE... NEAR TERM /THROUGH TUESDAY/... As of 930 PM Monday...No significant changes are needed to wind or wave forecasts overnight. I anticipate scattered showers and a few t-storms to develop near the South Carolina coast in the next several hours, spreading northeastward toward Cape Fear before daybreak Tuesday. -TRA Discussion from 300 PM follows... Quiet conditions continue across the coastal waters with winds under 10 kts and seas under 3 ft. Although somewhat variable winds right now, a southerly flow will develop and increase through Tuesday as gradient tightens between Bermuda High to the east and approaching cold front from the NW. Expect S to SW winds 10 to 15 kts by early Tues and increasing to 10 to 20 kts through Tues aftn. This will push seas up from less than 3 ft through much of tonight to 3 to 5 ft by Tues aftn Seas with some 6 fters possible by the end of this period. Shorter period wind waves will begin to mask a longer period fading swell. SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 300 PM...Southwesterly flow ahead of a cold front Tuesday night will reach 15-20 knots, then diminish Wednesday as the boundary moves across the waters. Seas are expected to remain in a solid 3-5 ft range Tuesday night, with some 6 ft seas not out of the question around Frying Pan Shoals and the outer waters from Cape Fear northward Tuesday evening. Numerous showers and thunderstorms are expected along and ahead of the front, which will slowly make its way south of the South Santee Wednesday night. A postfrontal northeast surge of 15-20 knots will occur Wednesday night. LONG TERM /THURSDAY THROUGH SATURDAY/... As of 300 PM Monday...No significant increase in wind or waves through the period and we shall stay below advisory or headlines criteria. There is still some uncertainty however regarding wind direction. The period will start with a front to our south; one that is eventually slated to return northward. As this happens the flow will veer from easterly. The current forecast has this happening a bit slower than previously with the veering not happening until Thursday night into Friday. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...MBB NEAR TERM...TRA SHORT TERM...CRM LONG TERM...MBB AVIATION...DL
Area Forecast Discussion
National Weather Service Marquette MI
622 PM EDT Mon Jul 16 2018 .SHORT TERM...(This evening through Tuesday) Issued at 407 PM EDT MON JUL 16 2018 WV imagery and RAP analysis indicated a mid/upper level low just west of James Bay resulting in cyclonic wrly flow through the nrn Great Lakes. At the surface, gusty west winds of 20-25 mph (higher gusts of 30-35 mph over the Keweenaw) prevailed between 1018 mb high pres into the nrn plains and a 1002 mb low at the south end of James Bay. Although Much drier air has moved in with dewpoints into the mid 40s, under sunny skies temps have still climbed into the upper 70s with low 80s in downslope locations. Cooler air behind a secondary cold front was moving into ne MN and nrn Lake Superior. Tonight, dry conditions and mostly clear skies with diminishing winds will result in good radiational conditions. However, there may be enough low level winds to maintain some mixing, especially over the est half. Satellite trends and models fcst RH suggest clouds may increase over the n cntrl and east late which will also keep temps from falling off as far. Nevertheless, expect temps to drop into the upper 40s interior west to mid to upper 50s south central in continued nw downslope flow. Tuesday, any morning clouds should dissipate by midday. Sunshine/mixing with 850 mb temps into the 8C-10C range will support highs in the mid and upper 60s north to low and mid 70s south. .LONG TERM...(Tuesday night through Monday) Issued at 311 PM EDT MON JUL 16 2018 High pressure pushing east across the Upper Great Lakes Tuesday night into Thursday this will favor the continuation of less humid and more seasonable temperatures. Tuesday night has the potential to be a rather chilly night inland from the Great Lakes due to strong radiational cooling and light winds. Some bias-corrected data are hinting at some locations possibly dropping into the upper 30s in spots. Confidence is not high as to whether or not temperatures will drop that low as it will depend on how low dew points get during the day on Tuesday. As surface ridging crests the Upper Great Lakes on Wednesday, expect a five star weather day with seasonable temperatures, comfortable humidity levels, and light winds with ample sunshine! Wednesday night through Thursday, low-level moisture and cloud cover will gradually increases as surface ridging slides southeast of the region and return flow develops across the Middle/Upper Mississippi Valley as a shortwave trough begins to eject out of the Plains towards the Great Lakes region. Ahead of this trough, 850mb temperatures will warm slightly, so expect temperatures to gradually warm back up into the lower 80s on Thursday. Late Thursday through early Sunday, the above mentioned shortwave will gradually move into the region and slow it`s eastward progression as it becomes cutoff low later in the week. What this means is we`re looking at increased chances for precipitation during this time period, as well as cooler conditions. As for precipitation amounts, there is quite a bit of uncertainty in regards to how widespread precipitation will be and/or who will see the higher amounts. This will be highly dependent on the track of the system as it moves across the Great Lakes and where mesoscale processes aid in augmenting precipitation totals. Tagging on with the precipitation chances, depending on the track of the system we could also see windier conditions as well. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 622 PM EDT MON JUL 16 2018 Expect VFR conditions through the forecast period. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 407 PM EDT MON JUL 16 2018 High pressure gradually building into the region will bring diminishing winds tonight. By Tuesday, the high pressure will build across western Lake Superior, so expect the gustier winds to around 20 knots be confined across eastern Lake Superior. Later in the week, high pressure will move across the region bringing light winds on Wednesday/Thursday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...Ritzman AVIATION...07 MARINE...JLB
Area Forecast Discussion
National Weather Service Blacksburg VA
733 PM EDT Mon Jul 16 2018 .SYNOPSIS... An upper level disturbance will track across the region this evening into tonight. A cold front will pass through the area Tuesday. High pressure will build in for Wednesday. && .NEAR TERM /THROUGH TUESDAY/... As of 720 PM EDT Monday... Not much coverage overall, but several small areas of showers/thunderstorms, especially along the southern Blue Ridge and into NE TN close to upper shortwave. Should see more of a scattering of shower/storms this evening in the west and isolated in the east if any. Things will subside in the east by midnight, then more showers/storms are expected ahead of an MCV by dawn Tuesday in the WV mountains. Previous discussion... An upper level disturbance, shortwave aloft will travel east across the region this afternoon into tonight. Cooling aloft associated with this feature will create steepening mid level lapse rates this afternoon. After a lull in convection this morning due to cloud cover, coverage in showers and thunderstorms will increase this afternoon into this evening. The primary focus of storms will be along and west of the Blue Ridge with the best low level convergence from southerly winds as supported by NAM,GFS and ECMWF. The Namnest, SPC HRRR3 and HRRR were hinting at slightly better coverage across the north. With slow moving deeper convection, there is the potential for localized heavy rainfall. With high PWATs between 1.50 to 2.00 inches and slow moving storms, rain rates may exceeding 3 inches in an hour. Antecedent conditions are dry with stream levels at or below normal, however, high rates can/will quickly compromise storm drains and poor drainage areas. WPC Day 1 excessive rainfall highlights the flood potential with the marginal threat area. An isolated strong to severe pulse thunderstorm may also be possible this afternoon. However, with little shear and organization present, most storms will remained well below severe criteria. Overall areal coverage of showers and thunderstorms is expected to decrease tonight with loss of solar heating, but threat will not entirely go away due to the soupy airmass, lingering outflow boundaries, and an approaching cold front from the Ohio Valley, all of which will provide as a lifting mechanism for nocturnal showers in the west. Areas of low clouds and fog will develop overnight into Tuesday morning. It is going to be another mild night with low temperatures ranging from the mid 60s in the mountains to the lower 70s in the piedmont. A cold front should reach the western mountains Tuesday morning and rotate east Tuesday afternoon across area. Convergence from frontal boundary and a weakly defined lee trough just east of the Blue Ridge should foster scattered to numerous showers and thunderstorms. The potential for locally heavy rains will continue Tuesday with high PWATs. The severe threat will be limited mainly by the instability and timing of the boundary. The Day 2 convective outlook placed the greater severe threat to our northeast with marginal to slight from mason- dixon line north into New England. High temperatures Tuesday will vary from the mid 70s in the west to around 90 degrees in the east. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 210 PM EDT Monday... A cold front will clear the mountains and foothill counties by the evening then Southside VA around midnight. Most of the forecast area will stay rain-free through the rest of the period as dry high pressure wedges south into the Carolinas. The only exception will be across the Mountain Empire to the Bluefield WV where the wedge will erode and an inverted surface trough stretches north from the Tennessee Valley to the southern Ohio Valley Thursday. Coverage of convective will be scattered. Shower will fade during the evening. Models are not quite as dry with the wedge in the lower level as previous run have been. The theta-E boundary stalls along the 460 corridor Wednesday, then drops to the VA/NC border Wednesday night. With more moisture in the lower level, we can expect thick stratus clouds along and east of the Blue Ridge to hang around through the morning, possibly into the afternoon. Temperatures Wednesday morning will range in the 60s with the higher values being south of 460. If clouds burn-off by the early afternoon, temperatures will range from the upper 70s to lower 80s across the mountains to mid 80s east. With the theta-E boundary moving south Wednesday night, slightly cooler temperatures are possible with mid to upper 50s across the mountains and lower 60s east. The theta-E boundary retreats north on Thursday but the area will maintain a cool easterly flow. This setup along with thick low clouds will have uniform temperatures across the area Thursday, ranging from the upper 70s to lower 80s west of the Blue Ridge to the mid 80s east. && .LONG TERM /FRIDAY THROUGH MONDAY/... As of 230 PM EDT Monday... The wedge will hang around again on Friday, but will erode from the west and southeast. An upper level trough is expected to become a close low over the Great Lakes on Friday. This low will send short waves into the Ohio Valley and erode the wedge from the west. Across the Southeastern states, a tropical disturbance is expected to track along the wedge boundary, then off the North Carolina coast Friday night. As this disturbance advances north, it will erode the wedge from the southeast. By the end of the day Friday, the wedge may be nestled along the VA foothills and linger into the night. Areas outside of the wedge Friday could see scattered showers in the afternoon and evening hours. On Saturday, the closed low expands into the Deep South and covers most of the US from the Mississippi Valley eastward. In the afternoon, there is a negative tilt to the trough in the eastern US that could bring active weather to the region. A weak cold front will then slide across the region Saturday night. Sunday and moreso Monday, could be active days with heating occuring under the cold pool. The area will remain under a trough through most of next week as a strong blocking ridge drifts westward in the Western Atlantic. Afternoon and evening showers and thunderstorms are likely each day from this weekend into the following week. Temperatures will run at or cooler than normal through the period. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 723 PM EDT Monday... Expect showers, maybe thunderstorm in vicinity of most sites this evening for another hour before activity weakens or diminishes. Should be mainly VFR with at times MVFR/IFR cigs. Fog again possible overnight in the mountains, but cloud cover ahead of front will act to keep it limited. Still going LIFR at LWB for a small window in the 10-12z time frame. Confidence is medium on this happening. A cold front will reach the mountains Tuesday morning and move east across the region Tuesday afternoon. There is a continued threat of MVFR/IFR with storms associated with the cold front. Medium confidence in ceilings, visibilities and winds during the taf period. Extended Aviation... The cold front will continue to move east into Tuesday night with post frontal drying Wednesday. Return flow will bring moisture back into the area Thursday and Friday. Scattered showers and thunderstorms with sub-VFR conditions are expected Saturday and Sunday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...KK/PM NEAR TERM...KK/WP SHORT TERM...RCS LONG TERM...RCS AVIATION...KK/PM/WP
Area Forecast Discussion
National Weather Service Shreveport LA
947 PM CDT Mon Jul 16 2018 .UPDATE... Latest regional radar mosaic showing scattered convection across far NE LA and east of the Mississippi River attm with a general southward motion. The western flank of this activity extends into the MLU area but the coverage is isolated to widely scattered at best. Convection earlier that was dropping south of the Red River across SW AR into NE TX has since dissipated. For the update this evening, the latest runs of the HRRR and the 00z NAM output not showing much more in the way of convection overnight except across extreme S AR and NE LA where an outflow boundary can be seen in our ground cover pattern per the KSHV WSR-88D. For this reason, have left slight chance pops going for the remainder of the night across our northern and eastern most zones. Taking a look at temps, hourly numbers were quite a bit lower across our northern zones than this time last night and this was due to overturned airmass from previous convection. Closer to the I-20 Corridor, temps were very near those of last night. Did bump up temps slightly across NE TX, especially near the TYR area where upper 70s have been common the last couple nights. Only other change was to the sky grids to account for expanding cirrus shield that may help to hold temps up as well overnight. Update out shortly...13. && .PREV DISCUSSION... /issued 515 PM CDT Mon Jul 16 2018/ AVIATION... The upper level ridge axis has retrograded to our west and northwest and that has allowed upper level disturbances to ridge the eastern flank of this ridge axis and interact with moisture and instability with the end result being scattered convection. Looking at the latest progs, it appears that the ridge will have enough influence on our NE TX terminals and the SHV terminal to leave any mention of convection out of this TAF package through the next the next 24 hours, though it may be close at the SHV terminal during the morning hours on Tue. Concerning the TXK/ELD and MLU terminals, will prevail VCTS through the next 24 hours with this scattered convection coming and going over the TAF period. No definitive window in the short term progs allows for the breaking up this long period of VCTS at these locations. Also added a TEMPO group this evening for limited VSBY and -TSRA at the ELD terminal as this terminal appears the most under the gun to see convection early on. Winds will be mostly from the south and southwest below 10kts overnight and through the day Tuesday, except variable in and around -TSRA at the TXK/ELD and MLU terminal through the TAF period. 13 && .PRELIMINARY POINT TEMPS/POPS... SHV 79 99 78 99 / 10 10 10 20 MLU 78 95 76 94 / 20 40 30 30 DEQ 74 93 73 95 / 20 30 30 20 TXK 77 97 76 96 / 20 30 20 20 ELD 76 95 75 95 / 20 30 30 30 TYR 79 98 77 100 / 10 10 10 10 GGG 78 98 76 100 / 10 10 10 10 LFK 75 97 75 99 / 10 10 10 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 13/13
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Tuesday) Issued at 342 PM CDT Mon Jul 16 2018 Forecast area this afternoon remains on the southern periphery of a surface high translating eastward across the Northern Plains, associated with the back side of an upper trof extending northward out of the Great Lakes. Between the weak surface reflection of the boundary and shear vorticity aloft, showers and thunderstorms have developed in north central Kansas this afternoon. Wind profiles in the soundings remain very weak, with the NAM sounding at Hebron barely breaking 10kts through the first 10kft off the surface. CAPE values remain summer like, with around 2000j/kg surface based, and enough dry air in the lowers 5000ft of the soundings to make collapsing storms pose a heavy rain then wind threat for today. Better ingredients lie farther northeast, but lack of a boundary to focus the lift keeps better chances in north central and central Kansas. Much of how the forecast plays out for Tuesday will depend on how nocturnal convection develops to the northwest and propagates southeast. There is a broad concensus that convection over the high plains in Wyoming late tonight moves southeastward into Nebraska overnight, with favorable corfidi vectors to bring that into our area. However, convection to the south over the panhandles and into south central and central Kansas may limit the amount of moisture transport northward by the nocturnal LLJ, leaving in question how strong the cluster would be before it got this far southeast. Certainly would anticipate at least remnants making it this far, which could then in turn aid as a focus for storms later in the day. As for the line across central Kansas, storms that develop along the mid level front should also move to the southeast, and the RAP giving some indication of a complex over eastern Colorado that may follow that boundary to the southeast into the morning hours. Will keep a forecast with slightly higher pops across the southwest early, but then increasing across the north into the east into the afternoon. Stronger storms may still occur with any convective complex early, but once again a day with low shear and high cape will make strong storms possible into the afternoon. This in turn will also impact cloud cover and temperatures as well, and will start with highs around 90 south to middle 80s north. Lows tonight forecast in the upper 60s to near 70 before better rain chances come in. .LONG TERM...(Tuesday night through Monday) Issued at 342 PM CDT Mon Jul 16 2018 Multiple, ill-timed chances for precipitation linger through the week, with continued summertime temperatures at or slightly above normal. A broad, longwave blocking ridge holds through the period over the southwestern U.S., with the eastern CONUS longwave trough gradually deepening through the period as multiple shortwaves work across the Northern Plains. This will promote an active NW flow over the central United States. On Tuesday evening, one such wave will be located over Wyoming and aiding in the development of a convective cluster over the High Plains. The detailed evolution of this complex is not fully resolved by the various guidance, but there is a growing concensus that the MCS will build SSE into a 30-40 kt LLJ in western Kansas throughout the night on Tuesday and into Wednesday morning. The MCS should decay through the morning, but the uncertainty lies in how the MCS cold pool or cloud shield drives/hinders convective chances later in the day. These mesoscale details will likely not be fully resolved until Wednesday morning, but there is a modest chance that an outflow boundary lingering in central/eastern Kansas that will serve as the focus for renewed shower and storm development Wednesday afternoon. The H500 trough is also progged to deepen during this time over South Dakota and help promote synoptic ascent. The kinematic environment may be initially supportive of semi-discrete cells, but outflow boundaries are likely to quickly merge and promote upscale growth into a cluster or line with strong winds being the main threat. A backdoor trough wrapping around the departing H500 trough may generate another round of convection Thu afternoon in central SD that could propagate southeastward through Nebraska into eastern Kansas into Friday morning. There is some discrepancy amongst the 12Z GFS/EC in the timing of this wave and the resultant precip with the GFS being the more progressive of the two. After the passage of this system, the H300 ridge amplifies and keeps the pattern dry through the weekend. Temperatures during the period will be near average, though mesoscale cold pool influences are to be expected with any precip Wed and Thu. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 637 PM CDT Mon Jul 16 2018 VFR conditions are expected outside of convective activity. Models suggest that a complex of storms may affect the terminals after 14Z Tuesday and have added VCTS at this time. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...67 LONG TERM...Skow AVIATION...53
Area Forecast Discussion
National Weather Service Tucson AZ
235 PM MST Mon Jul 16 2018 .SYNOPSIS...Plenty of moisture and instability will remain in place to support daily showers and thunderstorms through at least the middle of the week. Some storms will generate strong winds and heavy rain. Partial drying from the east may lead to reduced thunderstorm coverage by the weekend, along with hotter temperatures. && .DISCUSSION...Daytime heating in combination with an inverted trough approaching the area were aiding in the development of showers and thunderstorms this afternoon in the mountains. A strengthening steering flow from the northeast to east in association with the approaching inverted trough will also help storms to move into the valleys today. Recent HRRR solutions supported the notion of storms tracking into lower deserts of Pima and Pinal counties this evening. Locally heavy rainfall will be the main concern, but the environment will also support strong thunderstorm winds. Models were in agreement with tracking the inverted trough through northern Mexico tonight and Tuesday with less of an influence for tomorrow`s thunderstorm potential. High pressure aloft will become established over the Great Basin region around Wednesday before shifting over the Desert Southwest this coming weekend. This adjustment in the position of the upper high will result in some warming and drying aloft by the end of the week. This warmer and drying will eventually translate to less thunderstorm activity and hotter daytime temperatures by week`s end. && .AVIATION...Valid through 18/00Z. Isolated to scattered SHRA/TSRA through late this evening can be expected. Cloud bases 8k-12k ft AGL with SCT-BKN clouds above 20k. Winds remain below 12 kts through the period, with stronger gusts possible around TSRA. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...An active weather pattern will continue to produce showers and thunderstorms, mainly during the afternoon and evening hours. Toward the middle of the week, a shift begins to take place bringing in drier air and reducing rain chances. However, isolated storms could still develop, especially over the higher terrain. Temperatures also gradually warm through the week. 20-ft winds remain below 15 mph, although the Upper Gila River Valley will experience gustier northwesterly winds at times. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at