Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/10/19

Area Forecast Discussion
National Weather Service Birmingham AL
650 PM CDT Mon Sep 9 2019 .UPDATE... For 00Z Aviation. && .SHORT TERM... /Updated at 0552 PM CDT Mon Sep 09 2019/ Perturbations/waves indicated on local radars across southeast Alabama indicate the atmosphere has become stable enough that marginally severe storms are not anticipated in the threat area anymore. The farther north you go, the drier the airmass becomes. Therefore, the rain chances go down greatly in the north to nothing. At the interface of outflow boundaries and the drier air, a few strong storms remain possible with some hail and gusty winds. The coverage will be very small and the storms that do develop will not move much. Some lucky isolated locations may receive an inch of rain before sunset. Otherwise, a slow rise in the moisture levels is anticipated as the warm front passes through Central Alabama. Lows overnight will range from 70 to 75 degrees. 75 Previous short-term discussion: /Updated at 0340 PM CDT Mon Sep 09 2019/ Made adjustments to the afternoon and evening weather grids to account for ongoing convection across south Central Alabama, and coverage spreading northward along an outflow boundary. Isolated to scattered activity will continue through early evening as an upper level shortwave rotates northward, pushing the stalled front to the north. With loss of daytime heating, expect coverage to diminish by late evening. Stronger storms could produce hail and damaging winds. See the below discussion for details. 14 Previous short-term discussion: /Updated at 1030 AM CDT Mon Sep 09 2019/ After a review of morning convective parameters & northerly advecting low-level moisture, a limited microburst risk may manifest across our southern counties this afternoon. Though it`s typically hard to forecast these isolated threats, it does appear best chances will reside generally along/south of US HWY 80 where PoPs generally range 30-45% through this evening. Some considerations we typically look for in these scenarios include favorable moisture & SBCAPE values, DCAPE, and the general ability for efficient heating & mixing in the low-levels/boundary layer. As such, increased dewpoints (low 70s) & PW values (above 1.5" per latest RAP mesoanalysis) across these areas will help foster SBCAPE as high as 3,000 J/kg this afternoon, as supported by the 12Z HREF mean. Also, our 12Z RAOB indicated plentiful dry air aloft (particularly in the H5-H7 layer) such that DCAPE will likely exceed 1,300 J/kg as well. The forecast microburst composite parameter for the afternoon yields "moderate" values with these & other related considerations. Though the troposphere is still somewhat dry on a broader scale, which usually hinders convective development/coverage, the narrow band of moisture situated along the remnant stationary front is more favorable for activity locally. Thus, will add mention of an isolated strong to severe thunderstorm (as they cannot be ruled out) in the above mentioned area to the HWO. The Heat Advisory will not be changed in these areas given we are still on track for a toasty afternoon across Central Alabama. 40/Sizemore .LONG TERM... /Updated at 0350 AM CDT Mon Sep 09 2019/ Tuesday through Monday. An area of enhanced moisture content, associated with a diffuse front, will become oriented from northwest to southeast across the forecast area on Tuesday. Isolated or scattered showers and storms are expected generally along and east of the I-65 and I-22 corridors. A strengthening upper-level ridge is expected to become more dominant for Wednesday through Friday, and any convective development should be very isolated. Hot conditions will continue for Tuesday through Friday with the ridge in place. Afternoon highs should reach the mid to upper 90s for many locations. Models are signaling a breakdown of the ridge for the weekend with a potential easterly tropical wave heading toward the Gulf of Mexico. This system could bring an increase in moisture and rain chances, but confidence is quite low at this time. However, the breakdown of the upper-level ridge should result in a downward trend in afternoon highs. 87/Grantham && .AVIATION... 00Z TAF Discussion. A warm front has moved through Central Alabama and was helped by the thunderstorm outflows. This was the leading edge of some higher moisture. Most of the area will be too dry, lack a forcing mechanism, or has become stable this evening. Therefore, only left with a VCTS at ANB/ASN for a hour or so since they reported it at release. Otherwise, clouds will be decreasing this evening with winds becoming light to calm. Due to the moisture increase area wide overnight, have included some prevailing MVFR vis due to fog at several places. The duration will be rather short and around sunrise. On Tuesday, wind become south to southwest by afternoon and generally around 6kts. Shower and thunderstorm activity will be limited due to forcing and limit mention to PROB30 at ANB/ASN. 75 && .FIRE WEATHER... Moisture continues to increase through mid week, with minimum RH values in the 40 percent range Tuesday and Wednesday. Isolated to scattered rain chances expected each afternoon for mainly eastern portions of the area. 20ft winds will be from the south to southeast each day, below 6 kts. KBDI values will remain elevated due to ongoing drought conditions. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 71 94 68 94 69 / 10 30 20 20 0 Anniston 72 95 70 94 70 / 20 30 20 20 0 Birmingham 75 95 72 95 72 / 10 20 20 20 0 Tuscaloosa 74 95 73 95 72 / 20 10 10 10 0 Calera 73 95 70 95 70 / 20 20 10 10 0 Auburn 73 93 71 92 71 / 20 30 20 10 0 Montgomery 74 96 72 96 71 / 20 20 20 10 0 Troy 71 95 70 94 70 / 20 20 20 10 0 && .BMX WATCHES/WARNINGS/ADVISORIES/... Heat Advisory until 9 PM CDT this evening for the following counties: Autauga...Barbour...Bullock...Dallas...Elmore...Lee... Lowndes...Macon...Montgomery...Pike...Russell. && $$
Area Forecast Discussion
National Weather Service Denver/Boulder CO
745 PM MDT Mon Sep 9 2019 .UPDATE... Issued at 740 PM MDT Mon Sep 9 2019 Not much change in the grids for early this evening, but the HRRR and RAP13 want to develop one or two thunderstorms late tonight, primarily after 06z. Main concern is a 70-80 kt upper jet that stretches from northeast UT into northeast WY early this evening. By late tonight, the northeast plains could be under the right exit region of this jet. This coupled potential sfc convergence in response to deepening sfc low over southeastern CO or outflow from ongoing thunderstorms east of the cwa. Not exactly sure what to pin it on but the high resolution models all suggesting something developing late tonight. For this reason will add a slight chance of thunderstorms in the grids primarily north and northeast of Denver after 04z. && .SHORT TERM...(This evening through Tuesday) Issued at 316 PM MDT Mon Sep 9 2019 Drier air aloft is spreading in from the west but there`s still enough low level moisture for lots of shallow cumulus clouds over the mountains. There`s also more westerly wind aloft now that`s mixing down into the mountains and foothills. The drier air aloft should prevent convection though there`s a slight chance of a light shower or two over the mountains or near the eastern border. A weak speed max is forecast to create some lift across northern Colorado around midnight, and a few of the models generate some isolated showers. This looks like another thing that`s possible but not likely given the dry air beneath it, perhaps virga or sprinkles or very limited coverage if it happens. We`ll keep PoPs very low but will increase the clouds a bit. There may also still be enough moisture for some low clouds or patchy fog over the eastern portion of the plains for a few hours around sunrise. Tuesday is still pretty dry, but there is some mid level moisture creeping up from the southwest which may be enough for some isolated weak thunderstorm activity late in the day. One other issue is that the stronger winds associated with tonight`s little wave do extend down to mountaintop level, so it will be fairly windy over the mountain ridges tonight with 40-50 mph gusts possible. These should subside quickly enough Tuesday that the afternoon gusts in the valleys and foothills won`t be much stronger than today. .LONG TERM...(Tuesday night through Monday) Issued at 316 PM MDT Mon Sep 9 2019 For Tuesday night, Colorado will be under a southwest flow aloft while a strong upper trof digs into the Great Basin with weak QG ascent moving into Colorado. Appears enough moisture will result in some showers/storms mainly mountains and far northern plains during the evening. The next weather player will be a rather strong upper level disturbance which will move across the northern Rocky mountain region on Wednesday. The QG forcing will be strongest further north into Wyoming but there will be some weak to moderate ascent which will help in shower and thunderstorm production across northern Colorado. The best chances of storms will be in the mountains and far northern plains bordering with Wyoming and Nebraska. Across much of the northeast plains, surface trof will be over northeast Colorado with surface winds mainly west and southwest to the west and south of the surface low. This will keep low levels on the dry side with only a slight chance for showers and storms. For Thursday, there will be a dry and subsident airmass which will move in behind the trof with a moderate northwest flow aloft. Main impacts will be strong and gusty winds which will develop Wednesday evening and continue through midday Thursday. Cross sections showing cross barrier flow increasing to 40-45kt by Wednesday evening which could result in wind gusts in the 40 to 60 mph in the higher mountains through Thursday morning before decreasing in the afternoon. For Friday, the flow aloft will shift more westerly with mainly dry and warmer conditions as 700mb temperature rise to around +12C. With a returning moist, low level southeast flow could see a few storms out towards the far eastern plains of Colorado. The entire weekend and into early next week looks dry with a weak to moderate west to southwest flow aloft. Temperatures will be back into the mid and upper 80s across the plains and wouldn`t be surprised to see a few 90 degree readings across the plains. The next chance of any active weather will likely not come until the middle of next week as the next upper trof drops into the Great Basin. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) Issued at 740 PM MDT Mon Sep 9 2019 VFR through tonight. easterly winds are expected to become S/W drainage this evening, then a weak Denver cyclone will likely shift the winds at KDEN/KAPA to W-NW by morning. Light variable or east winds are expected again Tuesday afternoon. High resolution models suggest thunderstorms development north and east of the terminals from around 04-12z tonight. Confidence in this is low to medium, so will not include this in the terminals at this time but will be watching how things develop this rest of this evening. Thunderstorm activity Tuesday will be isolated at most and likely south and west of Denver. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Cooper SHORT TERM...Gimmestad LONG TERM...Entrekin AVIATION...Gimmestad/Cooper
Area Forecast Discussion
National Weather Service Cheyenne WY
522 PM MDT Mon Sep 9 2019 .SHORT TERM...(This evening through Wednesday night) Issued at 231 PM MDT Mon Sep 9 2019 Main concern this period will focus on strong to severe storm potential over parts of the CWA Tuesday afternoon and evening. Quiet weather expected overnight into Tuesday. HRRR did show some convection near the Colorado border east of CYS later tonight but latest runs have removed it. Have shaded in some very low pops for now as a weak impulse does appear it will lift across the area later tonight so not totally out of the question. Tuesday will see swly flow aloft over the area ahead of the next upper trough. At the same time a surface boundary should drop south over the plains. SE winds behind this boundary should bring in some moisture and latest NAM really upping the CAPE over much of the Panhandle/extreme ern Wy to over 2000 J/Kg by mid-aftn. Should see some convection fire around the sfc boundary in the afternoon and move ENE with the most likely area north of the North Platte River. Parameters should be in place for strong to severe storms with hail looking the main threat. Strong storms should move out of the CWA Tuesday evening then widely sctd general showers and tstms expected Tuesday night and Weds as the upper system approaches the area. .LONG TERM...(Thursday through Monday) Issued at 231 PM MDT Mon Sep 9 2019 An upper low will move across the Dakotas Thursday and push a cool front across the CWA. A few wrap-around showers possible over northern parts of the CWA. After that a generally dry and warm weather pattern expected over the area under westerly flow aloft. Some windiness possible mainly around the mtns in the afternoon but not seeing high winds at this time. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 522 PM MDT Mon Sep 9 2019 VFR conditions currently at all area terminals with gusty winds continuing until 01Z tonight. Isolated showers and thunderstorms are possible tonight between 08Z and 012Z, especially near KCYS. HRRR and NAMNEST have shown this possibility, however latest runs have decreased coverage of storms around the CO/WY border. Scattered thunderstorms are expected Tuesday afternoon and evening with the chance of erratic wind gusts, hail, and lightning. Storms will most likely not move into the Nebraska Panhandle until after 23Z Tuesday evening. && .FIRE WEATHER... Issued at 231 PM MDT Mon Sep 9 2019 Overall concerns look to remain on the low side for the next several days with mi RHs expected to stay above critical levels. Showers and tstms are expected mainly over the plains Tuesday afternoon and evening then be somewhat more widespread over the area Weds into Thursday as a low pressure system moves across the region. Some uptick in fire weather concerns next weekend as breezy conditions and drier air look to return. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...RE LONG TERM...RE AVIATION...MB FIRE WEATHER...RE
Area Forecast Discussion
National Weather Service Wichita KS
701 PM CDT Mon Sep 9 2019 .SHORT TERM...(This evening through Thursday night) Issued at 259 PM CDT Mon Sep 9 2019 Showers and isolated thunderstorms continue to linger through mid day across portions of central and south central KS. These showers have largely been contained within a pocket of climatologically high PWs (1.5 inches) in a narrow area of 310K isentropic upglide. The best moisture transport has been slowly shifting northeast of the area later today which should continue to help shut down the remaining showers late this afternoon. Chances of showers and thunderstorms will commence again tonight. Most showers/storms will likely wait till later in the evening to get going as the 40kt LLJ kicks up near the 03-06z timeframe. Storms overnight are not expected to be severe, a couple may be strong with small hail and gusts up to 50 mph. Kept low pop chances into late morning tomorrow generally in the forecast pocket of 1.5 in PWs given todays tend. Moisture transport and upglide will still generally be favorable to produce a few showers over portions of central and south central KS. Shower/storm coverage across the area in the morning will be less than any overnight convection if they do persist, given relatively weaker moisture transport (except RAP which increases slightly around 12z). Otherwise expect breezy conditions again across portions of central KS with some of the cloud clover diminishing late tomorrow to help warm temps into the upper 80s. Lower confidence in convective activity tomorrow afternoon and night. There is a short time where central KS becomes nearly uncapped with 2000 J/kg MLCAPE that would support a strong to perhaps marginally severe storm given about 20-25kts bulk shear. However whether a storm initiates early afternoon remains a challenge as upper ridging will be slowly building and will likely inhibit storm development. Even later into the evening confidence isn`t great in storms impacting the area, perhaps isolated thunderstorms possible over the I-70 corridor when the LLJ picks up. However, it seems the best moisture transport would be directly over portions of central and south central KS so thinking is that the best chances of any showers and storms would fall on the northern fringe of the CWA or north thereof. Thus kept pops silent across central KS for now. A deep upper trough will traverse across the Northern Plains and push a seasonably strong sfc low across the Northern Plains and Upper Mississippi Valley. A trailing cold front extending from the sfc low will move southeastward through Kansas on Thursday. The cold front will bring decent chances of showers and thunderstorms to most of the area as it pushes through. Current models push the front into northern Oklahoma by early morning Friday. .LONG TERM...(Friday through Monday) Issued at 259 PM CDT Mon Sep 9 2019 Sfc high pressure along with drier and cooler air in the wake of the cold front can be expected to start off the weekend. Expect high temperatures behind the front on Friday to top out near 80 degrees. Seasonable temps expected Saturday with highs in the mid 80s. Zonal flow over the area Saturday could allow a subtle shortwave to pass through the area, but in general still looking dry for the weekend. Southwest flow Sunday and Monday will help warm us back up to the upper 80s to near 90 degrees across the area. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 701 PM CDT Mon Sep 9 2019 VFR conditions are expected for the first 12 hours and possibly for the next 24 hours. SubTropical moisture plume continues over the the western half of the forecast area for tonight into Tue. This low level moisture transport slowly increases again during the early morning hours on Tue. This will lead to showers and even some rumbleS of thunder again increasing for areas west of the KS Turnpike early on Tue morning. So will reintroduce a VCSH mention for most of the central KS taf sites after 08-09z time frame. Could even see an uptick in the shower coverage by sunrise on Tue for most of central and south central KS ( a little further east than this morning). Elevated instability looks a little better for Tue morning, so could see more TSRA than SHRA by Tue AM so will mention a VCTS for KGBD and KRSL by around 14z/Tue. Ketcham && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 72 89 73 89 / 30 20 10 0 Hutchinson 72 88 73 88 / 30 20 10 10 Newton 71 88 72 88 / 30 20 10 10 ElDorado 72 88 72 89 / 30 20 0 10 Winfield-KWLD 73 90 72 89 / 20 20 0 10 Russell 70 88 72 89 / 20 20 10 0 Great Bend 71 88 72 88 / 20 20 10 0 Salina 72 89 73 89 / 30 30 10 10 McPherson 72 87 72 87 / 30 20 10 10 Coffeyville 71 90 71 90 / 10 10 0 0 Chanute 71 89 71 89 / 10 10 0 0 Iola 71 89 71 89 / 10 10 0 0 Parsons-KPPF 71 89 71 89 / 10 10 0 0 && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...KMB LONG TERM...KMB AVIATION...Ketcham
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
827 PM CDT Mon Sep 9 2019 .UPDATE... Issued at 826 PM CDT Mon Sep 9 2019 A forecast update is in place for isolated thunderstorms across the srn Nebraska Panhandle. && .SHORT TERM...(This evening through Tuesday night) Issued at 300 PM CDT Mon Sep 9 2019 Concerns in the near term revolve around the threat for severe weather and potentially heavy rainfall Tuesday and again Wednesday. Quiet day for the most part Monday afternoon as dry air wraps itself into the departing system. This effectively ended precipitation chances by midday with a pleasant afternoon as a result today. Weak convergent boundary generally along a LBF to ONL line allowing for some afternoon cumulus to develop. SPC Mesoanalysis indicates some modest lapse rates over-top this boundary with some models trying to hint at the potential for an isolated shower or thunderstorm to develop later this afternoon into the evening. Thinking this potential is quite low given lack of stronger forcing and magnitude of dry air in place. Also, a warm nose within the h85-h7 layer should effectively keep us capped as well. Some model output suggests the potential for a modest low-level jet nosing into northeast Colorado and eventually sparking rain and thunderstorms that move into portions of southwest Nebraska early Tuesday morning. Biggest proponent of this thought has been morning runs of the HRRR and, to a lesser extent, the RAP. HREF probabilities in this area are fairly low with no support of this idea from the SREF or NAM so will keep the forecast dry but will need to monitor this potential. With the expectation of dry conditions overnight and clear to partly cloudy skies, expecting lows Monday night to fall into the low 50s across northwest Sandhills to low 60s across the south and east portions of the forecast area. The threat for severe weather returns on Tuesday as a modest shortwaves within the southwest flow aloft moves onto the central high plains. At the surface, a warm front will lift north to near the Nebraska/South Dakota state line as lee- side cyclogenesis gets underway during the afternoon across northeast Colorado. This will put the local area squarely in the warm sector with breezy southeast winds helping push in higher dew points and allowing the area to see similar temperatures to what was seen Monday as high climbs into the 80s. Dew points will climb into the 60s to near 70 locally and combined with steep mid-level lapse rates overhead, will help moderate to strong instability develop as MLCAPE values climb into the 3000-4000 j/kg range. Aloft, a mid- level speed max will begin to encroach on the area with h5 winds AOA 35-40 knots. With surface to h85 flow generally out of the southeast, deep layer shear will be more than sufficient for organized severe weather with 0-6km bulk shear values of 40-50 knots. Given good veering winds in the lowest 3km, will see helicity values approach 300 m2/s2 and long looping hodographs will suggest all modes of severe weather possible, especially in close proximity to the frontal boundary. The lingering question that will play a large role in areas impacted will be final placement of the surface boundary. A shift north or south of 20 miles will make a big difference in areas that see severe weather and heavy rainfall or not. Current thinking is frontal boundary will set up somewhere near or immediately south of the Nebraska/South Dakota state line with model spread ranging from 20 miles south of the border to 30 miles north. In any event, will limit PoPs to "Likely" for all of the northern counties given uncertainties and with future fluctuations likely as models begin to nail down final placement as we get within 24 hours out. With this in mind, greatest areas of concern for severe weather will be along and north of a Oshkosh to Burwell line with the threat increasing as you head north. High moisture will be in place and with this boundary being the focus, the threat for training storms will exist and thus potentially localized flooding. The area of highest confidence to see this occur would be roughly along and north of Highway 20. Expect storms to develop by mid to late afternoon and be ongoing by the evening, moving quickly to the east. As thunderstorms move out of the area, will see PoPs along the border decrease during the overnight hours. With the increased cloud cover and rain, will see lows Wednesday morning range from the low 50s in the west to upper 60s in the east. .LONG TERM...(Wednesday through Monday) Issued at 300 PM CDT Mon Sep 9 2019 Beginning 12z Wednesday. Another active day is expected Wednesday as the atmosphere recharges for another round of potentially severe weather. Surface low pressure will develop across northeast Colorado with a surface cold front draped southwest to northeast across the central Sandhills. As the surface low moves up and along the frontal boundary by late afternoon into the evening, scattered rain and thunderstorms will develop. The environment will see high instability and strong deep-layer shear as mid-level flow maximizes to near 60 knots at h5. As the system moves into South Dakota, a cold front will begin to drift south and east through the local area. Will see PoPs reach "Definite" category as the front will provide strong forcing and lingering PWATs will be in excess of 1.25". Locally heavy rainfall will again be possible across the entire area, but given progression of the surface front, the potential for flooding will be lower than Tuesday night. Highs on Wednesday will range from the 70s in the northwest to upper 80s to the southeast. Will see most rain and thunderstorms linger through the overnight into Thursday before ending by midday with morning lows falling into the 50s to low 60s. A much needed stretch of dry weather arrives Thursday afternoon and lasts through the weekend. Following the departure of Thursday`s activity, shortwave ridging will build in overhead lasting into early Saturday. A quick moving northern stream system will move along the US/Canadian border with impacts expected to remain north of the local area as upper level dynamics largely miss the area. Weak surface boundary moves into the area Saturday but moisture will be scant so no precipitation is expected. Models tend to divulge in thinking thereafter with general thoughts being the area sees zonal to modest southwest flow develop by early next week as a large trough moves over the Pacific Northwest and ridging builds across the southeast. Looks like first real chance for appreciable precipitation will be Tuesday into Wednesday as energy looks to eject ahead of the digging trough over the northern Rockies. Temperatures in the extended will gradually warm Thursday through early next week as ridging builds in with values approaching above normal values in the Sunday-Monday timeframe. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 615 PM CDT Mon Sep 9 2019 VFR is generally expected overnight and Tuesday across western and north central Nebraska. Some valley fog is possible 11z-13z Tuesday morning but MVFR is predicted for the fog. Isolated to locally scattered thunderstorm coverage is expected from 20z onward Tuesday afternoon, generally affecting areas along and north of highway 2. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...CDC SHORT TERM...Jurgensen LONG TERM...Jurgensen AVIATION...CDC
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1006 PM EDT Mon Sep 9 2019 .SYNOPSIS... A front will push south of the area tonight through Tuesday morning. High pressure will then build over the area Tuesday through late week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 1005 PM Mon...Upper level support in the form of an H5 shortwave trough is departing late tonight and CIN continues to increase tonight. Lowered PoPs quite a bit tonight based on current mesoscale trends but kept slightly higher PoPs over the waters as HRRR continues to hint the front may be a foci for overnight convective development. Otherwise few other changes needed from the previous update. Prev disc...Scattered showers and thunderstorms will continue into the evening roughly along a quasi-stationary boundary that is slowly sliding south across the area. Instability will wane after sunset, but 2000-3000 J/kg lingering into late evening and sufficient effective shear will bring the potential for a few stronger storms producing gusty winds and small hail. Convective coverage will decrease overnight, but at least isolated coverage remains possible mainly south of the Tar/Pamlico River as weak moisture overrunning of the front continues. Low stratus will develop across most of the area late, with the stratus potentially building to the surface as fog at times. Lows overnight will be several degrees above normal with little airmass change behind the front. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... As of 345 PM Mon...A few showers remain possible across the southern tier tomorrow in proximity to the front which will continue to slide further south of the area as high pressure builds in through the day. Stratus coverage over much of the area in the morning will clear later in the day as somewhat drier air gradually fills in. Low level thickness values support highs several degrees above guidance despite the mostly cloudy skies in the morning, with highs in the mid to upper 80s for most. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... As of 2 AM Mon...High pressure dominates through Thursday. A tropical wave may affect the area by next weekend and early next week with some unsettled weather. Tuesday night through Thursday...The front gets pushed further south by midweek, with return to dry weather, and only slightly cooler temps as light nerly flow develops. Thicknesses/hts will remain above normal so temps will follow suite and remain above climo with highs well into the 80s...possibly touching 90 inland Thu. Friday through Sunday...Latest global model suite indicating return to swrly flow, to eventually serly flow, and increasingly warm and humid regime with flow off the Atlantic. Weak tropical wave increase shower/storm chances this weekend into early next week, though no organized low pres expected. Temps above climo expected with very humid conditions, highs in the 80s due to increasing clouds and showers, and lows in the upr 60s (inland) to mid 70s (beaches). && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Short Term /through Tuesday/... As of 750 PM Mon...Thunderstorm activity has waned this evening with a few slow moving cells not too far from KPGV this hour, although currently do not expect these cells to impact the terminal. With plenty of high cirrus lingering only an isolated storm or two remains possible tonight with confidence too low to mention in TAFs. Moisture overrunning still expected tonight with extended periods of low stratus and fog early Tuesday morning and lasting a few hours after sunrise with NE winds behind a frontal passage. VFR conditions should prevail by midday Tuesday. Long Term /Tuesday night through Friday/... As of 2 AM Mon...Pred VFR conditions expected through the period, though light NE flow through Wed night could bring some sub VFR each night in patchy fog or low stratus at times. && .MARINE... Short Term /through Tuesday/... As of 4 PM Mon...A front will slowly work across the waters through tonight, with light southwest winds ahead of the front and northeast winds behind it. Scattered showers and thunderstorms will bring locally gusty/erratic winds through this evening. Late tonight into Tuesday, high pressure building into the area will tighten the gradient, bringing northeast winds at 10 to 15 kt, with some gusts to 20 kt possible, through much of the day Tuesday. Seas generally 2-3 ft overnight, increasing to 2-4 ft as moderate winds develop Tuesday. Long Term /Tuesday night through Friday/... As of 2 AM Mon...Generally good boating conditions expected through the period. High pressure will build in behind the front through most of the week. E/NE winds 5-15 kt cont Wed then with the high over the area. Swrly to serly flow 5-10 kt then develops by Thu. Easterly flow increases a bit Friday to 5-15 kt as gradient tightens. Seas generally 2-3 ft Wed night through Fri. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...None. && $$ SYNOPSIS...MHX NEAR TERM...MS/CB SHORT TERM...CB LONG TERM...CQD/TL AVIATION...TL/MS MARINE...TL/CB
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
740 PM CDT Mon Sep 9 2019 .Updated for 00Z Aviation Discussion... Issued at 733 PM CDT Mon Sep 9 2019 && .SHORT TERM...(This evening through Tuesday night) Issued at 338 PM CDT Mon Sep 9 2019 Overall, the severe weather threat for this afternoon and evening is looking to be confined to far southern and southeastern MN. Showers and thunderstorms are still expected elsewhere, especially east of the I-35 corridor this evening, but severe parameters will be best from Iowa through far southeast MN and over into Wisconsin. As of 3PM this afternoon, convective initiation is underway south of the warm front which resides across central Iowa. The front will continue slowly lifting north this evening, with additional storms developing to our south. A strong low level jet will develop as well, oriented southwest to northeast from north central Iowa through southeastern MN. Expect storms to continue firing along the low level jet this evening. The front will lift into far southern MN early evening, bringing 1,000-1,500 J/kg into far southern MN. The latest HRRR solutions seem to make sense, with expanding thunderstorm coverage across Iowa this afternoon, lifting into parts of far south/southeastern MN by evening. There will be a tornado threat in the vicinity of the front, along with damaging winds and large hail especially south of the front. However, trends today have pointed towards storms evolving northeast from Iowa, and possibly staying east of I-35, mainly impacting the southeastern corner of the state (to the east of the MPX CWA). Still, this result is not certain and there will certainly be enough instability lifting north for folks across south central MN through west central WI to remain weather aware this evening. Farther north, cool conditions north of the front and a lack of instability will limit activity to showery with weak embedded thunder. The front will lift through late tonight, holding overnight temperatures in the 60s and setting the stage for a much warmer day on Tuesday. The strong low level jet will continue pivoting east overnight, and conditions dry out toward morning. A brief reprieve in the active weather is expected tomorrow with a ridge working through, and it will feel more like summer with highs near 80 and the dew points well into the 60s. The next wave will take aim at our area late Tuesday night. An embedded shortwave in deep southwesterly flow will likely produce fairly widespread showers and storms overnight into Wednesday morning. Overall the severe threat appear low for that period. .LONG TERM...(Wednesday through Monday) Issued at 338 PM CDT Mon Sep 9 2019 Active weather continues into the start of the long term period, then trends a bit quieter for the upcoming weekend. Expect showers and thunderstorms to be ongoing Wednesday morning as a warm front lifts toward southern Minnesota. This front will continue to lift north across the forecast area into Thursday, driven by a shortwave trough ejecting from the Northern Rockies to the High Plains. Southwest flow ahead of the trough will provide a continuous source of frontal overrunning, and combine with precipitable water values nearing 2 inches to make heavy rainfall a concern in the Wednesday-Thursday time frame. Given the potential for multiple successive bouts of heavy rainfall into Thursday, could envision the need for a flash flood watch at some point. The severe weather threat will largely be contingent on how much/if we scour out cloud cover on Wednesday afternoon/eve, and where the front is on Thursday. Friday into the weekend we return to zonal flow, so precipitation can`t be ruled out, but dry weather would be more prevalent. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 733 PM CDT Mon Sep 9 2019 MVFR/IFR conditions with low stratus, fog, and some drizzle along a warm front that is draped across the region. This warm front will lift northward overnight and into Tuesday morning which should allow conditions to improve during this timeframe. Meanwhile the winds of the low level will strengthen which could lead to some wind shear overnight. VFR conditions will return on Tuesday. KMSP... MVFR/IFR conditions this evening with low stratus, fog, and some drizzle along a warm front that is draped across the region. This should lift northward and allow drier air to bring VFR condition late tonight or at least by mid-day on Tuesday as winds become more westerly. /OUTLOOK FOR KMSP/ Wed...MVFR-IFR. Periods of SHRA/TSRA. Wind E 5-10 kts. Thu...MVFR-IFR. Periods of SHRA/TSRA. Wind SE 5-10 kts bcmg SW. Fri...Mainly VFR with MVFR ceilings possible. Wind W 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...SPD LONG TERM...LS AVIATION...JRB
Area Forecast Discussion
National Weather Service San Diego CA
130 PM PDT Mon Sep 9 2019 .SYNOPSIS... Low pressure across the West will bring cooler than average weather through Wednesday. The marine layer will be deep with low clouds during the nights and mornings west of the mountains. Areas of gusty west winds will occur during the late afternoons and evenings in the mountains and deserts through Tuesday. High pressure will build Thursday through next weekend, bringing warmer weather and less coastal cloudiness, followed by likely cooling early next week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Mostly sunny skies covered the region, with the low clouds mostly having cleared at the coast and some high clouds drifting over. Early afternoon temperatures were mild with mostly 70s to mid 80s west of the mountains, and 97 is the highest temperature in the desert, at Ocotillo Wells. today will be a little bit below normal under the influence of the broad trough over the western US. Gusty winds are expected to develop later this afternoon in the mountains and deserts, and the Miramar sounding did show a weak inversion in the 700-650 MB layer this morning, just above some of the mountain crests, which would support a mountain wave. Fortunately, winds are not too strong below the inversion, but local WRF and HRRR show gust potential around 45 MPH in strongest wind locations, such as east of San Gorgonio Pass. Miramar sounding had around 7% RH below that 700 MB inversion base, so some very dry air could be brought down to the desert slopes from the mountain wave. Fire weather risk will be locally elevated, but since most of the winds will happen after sunset as temperatures lower, the timing of the higher risk will be somewhat limited. Winds look even slightly stronger Tuesday. The trough axis will move through the Great Basin Wed morning with the marine layer generally being deeper tonight and Tuesday night, so stratus will likely spread well into the Inland Empire then, as well as where it has already been in OC and western SD County. High temperatures will slide a few more degrees Tue as well in all areas, with little change Wed. We will have a change in the weather Thu after the trough moves east and a ridge builds in from the east Pacific. Some weak offshore flow will develop mainly along and just below mountain crests Thursday, but current guidance suggests the winds will not be strong. Temperatures should increase again but with generally lower humidity and a limited marine layer along the coast. It will be very much like a typical early fall pattern, with little chance of any monsoonal action through early next week. Ensemble models start to diverge with their solutions early next week, but some solutions suggest another moderately deep trough moving through the West Coast early next week for cooling and a return of a more organized marine layer. && .AVIATION... 092020Z...Coast/Valleys...Mostly clear skies will prevail through the afternoon with breezy southwesterly winds at coastal TAF sites gusting up to 20 kts at times. MOD/HI confidence low clouds pushing ashore to SD coastal TAF sites after 02Z Tuesday, closer to 06Z across OC. Confidence on the lower end for cigs to reach into KONT/KSBD tonight after 11Z. Bases 1000-2000 ft MSL with tops close to 2500 ft MSL through the night. A robust coastal eddy tonight will bring gusty winds up to 20 kt once again through the night along the coast, as well as a slower burn off tomorrow later in the morning. Mountains/Deserts...Mostly clear skies and unrestricted vis through Tue. && .MARINE... Northwest winds with gusts to 20 knots are possible in the outer waters through this evening. Otherwise, quiet conditions expected through the middle of the week. && .FIRE WEATHER... Gusty west winds will bring somewhat elevated fire weather conditions to the desert slopes and lower deserts in the late afternoons and evenings today and Tuesday. Overlap between humidity below 15% and winds 25 MPH gusting 35 MPH or more will be mostly less than 6 hours and mainly restricted to areas near San Gorgonio Pass and the east slopes of the San Diego County mountains. Winds will be lighter Wednesday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC/FIRE...Maxwell AVIATION/MARINE...APR