Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/10/17

Area Forecast Discussion
National Weather Service Gaylord MI
1145 PM EDT Fri Jun 9 2017 .UPDATE... Issued at 1011 PM EDT Fri Jun 9 2017 All diurnally-driven shower activity has died with sunset as expected late this evening....leaving partly to mostly clear skies across our entire CWA. Winds have become light/calm...allowing temps to quickly fall thru the 60s...on their way to overnight lows in the upper 40s and lower 50s. Going forecast is on changes needed at this time. && .NEAR TERM...(Tonight through Saturday) Issued at 407 PM EDT Fri Jun 9 2017 ...Showers and Thunderstorms Ending by the evening. ... High Impact Weather Potential...None Pattern Synopsis/Forecast...Small 500 mb shortwave trough is pushing through the flow into N Lower and E Upper this afternoon and will continue into Lake Huron by 03z. Latest HRRR is handling this pretty well, maybe a little overdone, on qpf, but the general areas where the convection is breaking out pretty good. As the shortwave moves through, the drier air in the 700-500 mb layer (RH<20%) and around 850 mb (rh< 20% as well) clears things out. Saturday will remain dry as the 500 mb ridge builds into the region and pushes the main thunderstorm threats to the north of Lake Superior. This will allow our temperatures to warm to the lower to mid 80s. Primary Forecast Concerns...As this area of showers and thunderstorms moves through the region, they could linger a little longer than 00z, but the main idea is that they will die out as they lose heating. Temperatures Saturday could climb a little higher as the temperatures mix to about the mid to upper 80s, but cloud cover from convective debris across the lake, could affect the region so have gone with the middle ground. && .SHORT TERM...(Saturday night through Monday) Issued at 407 PM EDT Fri Jun 9 2017 ...Warmer, but periodic showers and thunderstorms... High Impact Weather Potential...periodic thunderstorm chances... marginal risk for severe storms. Primary Forecast Concerns...Thunderstorm/severe weather potential and temperatures through the weekend. Pattern Synopsis/Forecast...Trough/Ridge/Trough pattern across the CONUS this morning with a closed low off the PAC NW coast...ridging and warm air through the plains into the Midwest and a departing trough in New England. Upper level ridging/warm air will shift into the Great Lakes region this weekend...although flatten a bit as PAC NW trough migrates inland and short wave energy/surface low pressure eject through the northern plains and far northern Great Lakes region...along with a cold front that may settle into the northern lakes region by Sunday. This has big implications for temperatures...and our warming trend for northern Michigan may not end up as robust as earlier advertised as temperatures may be tempered by one or more convective systems/cloud cover/debris that will develop along the periphery of the ridge and along the front...not to mention the ultimate location of the front itself. Saturday night into Sunday...Aforementioned short wave energy and attending surface low will be sliding quickly through Ontario and Quebec with a trailing cold front folding into northern Michigan heading into Sunday. Convective development remains a possibility in the upper Midwest Saturday night...and sliding through the northern lakes into Sunday morning...with lingering cloud cover draping across northern Michigan a possibility for Sunday. Of course If that occurs...high temperatures for Sunday will be cooler than previously advertised...perhaps much cooler. A lot of uncertainty here, but plan is to beef up cloud cover and lower high temps for Sunday. But again, much will depend on convective evolution and where the boundary ends up. Front remains draped across the northern lakes region...back to another area of low pressure in the front range of the Rockies. Another round of showers/storms may develop again in the upper midwest late Sunday with pooling moisture/instability along the boundary and where stronger low level flow will be focused...and potentially sliding through the northern lakes region heading into Monday. Again, much uncertainty surrounds this pattern (where stuff will develop, where it goes) my inherited forecast with showers/storms Sunday night into Monday and a slightly cooler/ cloudier forecast for Monday. Severe weather possibilities...any convection that develops and moves through the region through the weekend will have a fair amount of instability and stronger mid level flow to work with and could produce some strong-severe outlooked with the SPC Day 2 and Day 3 products. .LONG TERM...(Monday night through Friday) Issued at 407 PM EDT Fri Jun 9 2017 The weather in the extended looks unsettled, to say the least. Models show waves passing over the great lakes ahead of a more robust low pressure system that will move through around Thursday. Timing of this activity will be the forecast challenge guidance indicates at least chance pops in each period through the extended. That said, I suspect we will lack the moisture for such continuous activity and instead will see shots of showers and even a few thunderstorms...with longer periods of rain free conditions. Thursday looks like the best day for the most widespread appreciable rainfall. Temperatures will run seasonal to a touch above...with daytime highs generally in the 70s, to lower 80s. Berger && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 1145 PM EDT Fri Jun 9 2017 Dry wx and mainly VFR conditions are expected at all TAF sites tonight thru Saturday evening. A warm front will lift thru the region on Saturday. No precip is expected across Northern Lower Michigan with the passage of this front. However...southerly winds will greatly increase once the front lifts thru the area. Surface winds will strengthen to 15 to 25 kts by Saturday afternoon with higher gusts expected. LLWS will develop by early evening in response to some low level decoupling and further strengthening of wind speeds just off the deck. && .MARINE... Issued at 407 PM EDT Fri Jun 9 2017 Tonight through Sunday...Winds will gradually increase tonight and into Saturday as the gradient tightens up winds look to ramp up to small craft sustained winds, in all of the nearshore waters. However, from Manistee to Grand Traverse Light am expecting the gusts to be over Gale force as the coastal convergence and the funneling of the Manitou Passage helps to accelerate wind speeds. Saturday night, as the low to the north, that tightened the gradient passes to the east, the gradient slackens winds will diminish. Sunday, winds and waves will be light and under 2 feet as high pressure passes through the region. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY from 10 AM Saturday to 6 AM EDT Sunday for LHZ345>349. LM...SMALL CRAFT ADVISORY from 10 AM Saturday to 6 AM EDT Sunday for LMZ323-341-342. GALE WARNING from 10 AM Saturday to 6 AM EDT Sunday for LMZ344>346. LS...SMALL CRAFT ADVISORY from 10 AM Saturday to 6 AM EDT Sunday for LSZ321-322. && $$ UPDATE...MLR NEAR TERM...JSL SHORT TERM...TBA LONG TERM...KAB AVIATION...MLR MARINE...JSL
Area Forecast Discussion
National Weather Service Bismarck ND
846 PM CDT Fri Jun 9 2017 .UPDATE... Issued at 829 PM CDT Fri Jun 9 2017 Quick update for observed trends through 01 UTC and CAM trends through the 00 UTC HRRR iteration. Severe convection will continue across the James River Valley for the next one to two hours. At the same time, covection continues to increase across southeast Montana. The 00 UTC HRRR, 21 UTC ESRL HRRR and 18 UTC NAM NEST continue to support intensitifaction of this convection into southwest and south central North Dakota late tonight in a highly sheared, strongly forced environment on the nose of a strong (75-80kt) 500 mb jet. Damaging wind gusts from high based and rapidly propagating storms is the primary threat, with large hail a secondary concern. UPDATE Issued at 519 PM CDT Fri Jun 9 2017 Quick update to issue severe thunderstorm watch #309 through midnight CDT. See SPC watch discussion for details. The 21 UTC HRRR, 18 UTC ESRL HRRR and the 18 UTC NAM NEST all support the continued threat for a second round of severe convection in a high shear/low CAPE environment entering from Montana between 04-06 UTC tonight and rapidly propagating east into central North Dakota. && .SHORT TERM...(This evening through Saturday) Issued at 302 PM CDT Fri Jun 9 2017 Potential for significant severe weather exists this afternoon all the way through the overnight, with two separate regimes yielding potential hazards. ...Severe-Risk Number One... * Location/Timing...Along and east of Highway 83 from about 21 to 03 UTC. * Scenario/Technical Discussion...Strong surface pressure falls of 3 mb/3 hours are driving gusty south winds and moisture return this afternoon as a lee-side pressure trough moves eastward. The nose of low-level warm air advection is focused near Minot as of 19 UTC, where the trough intersects a warm front producing a triple point of air masses. Surface dewpoints are running a bit lower than expected based on earlier model guidance, and they have dropped from 59 to 54 F at Bismarck between 1830 and 1930 UTC, suggesting the richer moisture is relatively shallow and is susceptible to reduction via mix-out. An early look at our 19 UTC special sounding verifies earlier model expectations for a strongly veering wind profile with its associated deep-layer shear vectors oriented normal to the surface trough in favor of discrete supercells where convective initiation occurs. The main uncertainty is how many updrafts will be able to survive their trip to the LFC given lingering capping (also shown on our 19 UTC sounding). CAM guidance has been exceptionally consistent in advertising a high probability of supercell development on the nose of the greater warm air advection, near the triple point, in the Bottineau/Rolette/Pierce County area by late afternoon. In that area, large low-level hodographs with 0-1-km SRH of 150 m2/s2 support a tornado risk, tempered by MLLCL heights near 1500 m AGL (though lingering cloud cover could keep surface moisture content relatively more protected from mixing in those areas in support of lower LCL heights). Further south, guidance is widely dispersive in whether isolated supercells will form in south central ND, so confidence is lower, but if any storms do become established the environment will be characterized by MLCAPE of 2000 J/kg and 40 kt of 0-6-km bulk wind shear. There`s long been a signal in sounding analog retrieval system output for very large hail in this setting. Again, though, only a few storms may develop, especially south of Highway 200, with this first severe risk. We greatly appreciate the research and academic groups, including NSSL and the College of DuPage, who are providing very useful sounding data across the area this afternoon as we determine when and where convective initiation will take place. ...Severe-Risk Number Two... * Location/Timing...Southwest and central North Dakota from about 03 to 12 UTC. The threat may be highest between Interstate 94 and Highway 2, but that area may be refined with later updates, with the most recent guidance suggesting the Interstate 94 corridor may be favored. * Scenario/Technical Discussion...Height falls aloft and an eastward-advancing cold frontal zone will likely generate deep, moist convection in southeast MT this evening with upscale growth and forward propagation downstream into ND overnight. It appears that late afternoon and early evening convection forced on the pre-frontal trough will not be widespread enough to overturn the instability axis over ND, and in fact the 12 UTC global suite and more recent RAP/HRRR iterations all suggest an enhanced elevated mixed layer pulse will surge into central ND in advance of the cold front, yielding very steep lapse rates of 8.5 C/km in support of MUCAPE from 1000-2000 J/kg despite low- level moisture that will not be particularly rich. Strengthening flow aloft will yield intense vertical wind shear with effective bulk wind differences of 60 to 70 kt. This scenario supports an outcome in line with today`s CAM simulations with a mix of both supercells and small bowing complexes racing northeast across the area overnight. Even if the updrafts are elevated, the very strong environmental flow and downshear MCS propagation vectors of 70+ kt support potentially destructive winds. CAM solutions including the large majority of the 12-17 UTC HRRR cycles have shown updraft helicity values of 100-150 m2/s2 with these storms in support of significant-severe potential. Even the 12 UTC NSSL WRF-ARW depicts a similar signal, and its HAILCAST output shows potential for golfball or larger size hail suggesting that wind- driven hail damage is possible. Experimental time-lagged HRRR convective guidance also strongly supports overnight wind and hail risks. The main uncertainty is coverage of this round of severe storms and how far south they form, but both the 12 UTC NSSL WRF-ARW and 17 UTC deterministic HRRR suggest that the Interstate 94 corridor, including Bismarck/Mandan, could be in the risk area. Note that this synoptic and mesoscale scenario does resemble the June 16-17, 2016, event enough for it to be considered a viable analog, but that of course does not imply the outcome will be identical, particularly with regard to which areas are impacted. A cooler, but still warm, and breezy Saturday will follow in the wake of tonight`s cold frontal passage. Steep mid-level lapse rates from cold advection aloft could yield a few showers north. Low-level drying will push afternoon humidities to 20 percent in parts of western and north central ND, but the spatio-temporal overlap of dry air, humidities, and dry fuels does not appear significant enough to warrant a red flag warning. .LONG TERM...(Saturday night through Friday) Issued at 302 PM CDT Fri Jun 9 2017 The main focus in the long term is on the dynamic and very strong upper-level low expected to lift from the Great Basin northward to Montana by Tuesday. The 12 UTC GFS and ECMWF both continue showing the greatest wrap-around moisture accompanying this wave remaining west of the local area in Montana. However, diffluent flow ahead of the wave Monday and early Tuesday will favor a wave of showers and storms lifting northward, with locally-heavy rain possible. A risk of severe weather will exist given strong wind fields and at least elevated instability north of a surface low that lifts northeast across the region. Depending on how far north the warm sector moves, surface-based storms are not out of the question. Finally, the close proximity of the cold-core low could favor a localized severe storm risk on Tuesday, as well. Thereafter, cooler and mainly dry cyclonic flow is likely during the latter parts of next week. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 829 PM CDT Fri Jun 9 2017 Severe thunderstorms will continue across the James River Valley through 03 UTC. Thunderstorms developing across southeast Montana as of 0145 UTC will continue to intensify and move into western and central North Dakota late tonight. Some storms may be severe with damaging winds and large hail. Thunderstorms are expected to cross the North Dakota and Montana border between 06-07 UTC and spread east rapidly. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...CJS LONG TERM...CJS AVIATION...AYD
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1153 PM EDT Fri Jun 9 2017 .AVIATION... Weak low pressure has moved east and remaining sct-bkn lower vfr deck will be east of KMBS by 06z (already clear elsewhere). VFR conditions are then expected the entire forecast period. Southwest winds will become gusty by midday Saturday with advent of warmer airmass. Gusts could approach 30 knots KMBS, but generally range in the 22-26 knot area during best afternoon mixing. //DTW THRESHOLD PROBABILITIES... * None. && .PREV DISCUSSION... Issued at 354 PM EDT Fri Jun 9 2017 DISCUSSION... Storm chances this evening will likely be followed by a lengthy period of hot and dry weather persisting from Saturday through next Tuesday. Temperatures will likely reach into the low 90s for several of those days. First off we`ll address thunderstorm chances for this afternoon and evening. Not too much has changed in the though process since the morning update. The morning shortwave continues to hang over a portion of the Detroit Metro with scattered showers ongoing. Satellite images now show the next wave and jet max surging through WI over Lake MI. A weak surface low drifting along a weakening trough laid out across far southern MI will be aided by an upper level shortwave and jet max to spark the next round of showers and thunderstorms. The shadow of Lake MI is producing a differential heating boundary which has started CUing up already. Surface temperatures have overachieved by a couple degrees adding a bit more surface based instability over the west side of the state, but both the HRRR and RUC SCAPE have decreased in recent model runs to below 500 J/kg. They`ve consistently been advertising a warm layer around 850mb to have to overcome to be sfc based so it`s not surprising with clouds hanging around keeping temps near 70, and the warm bubble around 850mb that SCAPE would be low. In the end, we still expect scattered thunderstorms to develop this evening across the area, with the best chance between I69 and I94 and mainly between 21- 01Z. A weak wind profile resulting in a lack of shear will keep a pulse type mode to the storms and should limit any severe potential. Big pattern changes coming this weekend. The persistent trough that has been plaguing the region for quite some time now will push off to the east while a deep upper low drops south over the West Coast. This will in turn bring about strong ridging across the Plains and into the Great Lakes. Both the GFS and EURO bring 850mb temps in the upper teens into the region, with decently dry air folding in from the Northern Plains. This should promote strong warming trend with temps around 90 Sunday through Tuesday. The baroclinic zone will be laid out to our north which may bring some nocturnal MCS activity through Mid/Northern MI at times, but will say mainly warm and dry for now and deal with short MCS`s on more of a short term basis. Looks like the upper low will drift eastward through mid week possibly sending a cold front through the region Tuesday night or Wednesday. A later passage may allow temps to again climb into the 90s on Wednesday. MARINE... A weak area of low pressure will slowly drift across Lower Michigan this afternoon and evening. Given the weak pressure gradient associated with this feature, surface winds will remain light an variable on Lake Huron. Developing southwest winds will increase on Saturday as a sprawling surface high remains parked over the southeastern United States. Warm temperatures advecting with these winds will greatly limit mixing depths over the lakes. The gradient along may however support gusts over 20 knots at times, particularly during the latter half of the weekend. The exception will be over the Saginaw Bay region Saturday evening and night, when a small craft advisory will likely be needed. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....DG DISCUSSION...DRK MARINE.......CB You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
908 PM CDT Fri Jun 9 2017 .UPDATE... Mesoanalysis reveals CIN quickly developing over the CWA with loss of daytime heating. As a result storms continue to diminish over the area, with just two lone cells remaining across southern Blanco and southwest Hays counties. These may impact portions of Comal county before dissipating over the next hour or two. Re-adjusted POPs and hourly T/Td trends for remainder of evening. && .PREV DISCUSSION... /ISSUED 650 PM CDT Fri Jun 9 2017/ AVIATION... /00Z TAFs/ There is an isolated severe threat mainly west of AUS, and a few showers and thunderstorms have a chance to produce lightning and gusty winds in the AUS vcnty through around 03Z. Afterwards, a benign forecast is expected with most of the rapid refresh models keeping the convection just outside the San Antonio metro area. Overnight skies should be partly cloudy for the most part but pockets of mvfr cigs are expected to form over the I-35 terminals toward daybreak. CIRA SIMWRF fog product has the clouds forming first at SAT/SSF, so the forecast will continue to show a slight delay before cigs form over AUS. PREV DISCUSSION... /ISSUED 305 PM CDT Fri Jun 9 2017/ SHORT TERM (Tonight through Saturday)... Main forecast concern through the next 6-12 hours will center around scattered storm chances for portions of the Hill Country and I-35 corridor. Rain chances have been increased during the 5pm to 11pm time-frame to 40% these areas. A storm or two may become strong with very localized wind gusts of 30-40 mph and small hail. This risk is low and coverage is not expected to be large across the region. Please see below for more details. Water vapor and RAP analysis depict a positively tilted trough shifting across NE Texas. The base of the trough will brush across south-central Texas through the afternoon and early evening and coincide with maximum instability near 2500 J/Kg. A weak capping inversion remains in place per aircraft soundings out of KAUS and KSAT but it should weaken just enough to allow for some isolated to scattered showers and thunderstorms to develop. Such convective development has already shown some signals of occurring north of the region near a small MCV apparent on visible satellite. Hi-res model trends continue to point towards the development of these showers and storms across the east Hill Country and northern I-35 corridor. With DCAPE near 800 J/Kg and weak upper level divergence, a storm may become strong with small hail and gusty winds. These storms should not have great overall coverage and remained confined to the I-35 corridor region through the late afternoon and evening. Expect what storms do develop to weaken by midnight. Saturday will be a quieter day as the trough actually closes off over the Texas coast but the region will be on the drier northern flow, negative vorticity advection area, with slightly lower PWATs. There could be some limited sea-breeze activity along the Texas coast but it unlikely to make into the coastal plains and have gone with a dry forecast with near normal temperatures. LONG TERM (Sunday through Friday)... Seasonal pattern of sea-breeze activity will be the main set-up through late weekend and through much of next week. Coastal plains will have a 20-30% chance of rain and general thunderstorms each afternoon with some of this making into the I-35 corridor late into the afternoons each day. Areas west of I-35 will remain hot and dry with heat indices reaching into the low 100s. A weak sub-tropical atlantic H5 ridge and weak H85-H7 inverted trough along the south Texas coast will aid in moist SE flow through the week. Daily sea-breeze activity is expected with little to no expected activity west of I-35. This pattern will persist through much of next week. Areas will warm into the low to mid 90s each day with some pockets of upper 90s along the Rio Grande. Heat index values will increase to 100-105F and precautions should be used during this heat. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 70 91 72 92 73 / 20 - - 10 - Austin Bergstrom Intl Airport 68 90 71 91 72 / 20 - - 10 - New Braunfels Muni Airport 69 90 70 92 72 / 10 - - 10 - Burnet Muni Airport 68 89 69 89 70 / 20 - - 10 0 Del Rio Intl Airport 73 96 73 96 73 / - - - 0 0 Georgetown Muni Airport 69 90 71 90 72 / 20 - - 10 - Hondo Muni Airport 71 93 71 93 72 / 10 - - - 0 San Marcos Muni Airport 69 91 71 91 72 / 20 - - 10 - La Grange - Fayette Regional 69 90 72 91 73 / 10 - - 20 10 San Antonio Intl Airport 71 91 72 93 73 / 10 - - 10 0 Stinson Muni Airport 71 92 73 93 73 / 10 - - 10 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Mesoscale/Aviation...Oaks Synoptic/Grids...Runyen Public Service/Data Collection...YB
Area Forecast Discussion
National Weather Service Grand Rapids MI
1147 PM EDT Fri Jun 9 2017 LATEST UPDATE... Aviation .SYNOPSIS... Issued at 314 PM EDT Fri Jun 9 2017 A dry and breezy day is expected Saturday as temperatures climb well into the 80s. Upper 80s to low 90s are forecast into the first half of next week before some cooler temperatures and a risk for rain returns. && .UPDATE... Issued at 943 PM EDT Fri Jun 9 2017 A few isolated showers remain over Gratiot and Isabella Counties but those will be gone soon. Otherwise a dry/pleasant night is in store with comfortable overnight lows around 60. && .SHORT TERM...(This evening through Sunday night) Issued at 314 PM EDT Fri Jun 9 2017 Scattered evening showers and thunderstorms, mainly east of US 131 and especially toward US 127, will give way to a dry overnight period and a dry (but breezy) Saturday. A few showers or thunderstorms may reach far west central Lower MI both Sunday morning and then again late Sunday. Severe weather looks unlikely for this region on Sunday but the threat is not zero. Still expecting some showers and perhaps a few thunderstorms to develop through the evening as the lake shadow presses inland and a surface low moves overhead. SBCAPE readings of 1000 J/kg or more are shown by the RAP and GEM which is sufficient for thunderstorm activity. With weak wind fields at the surface and aloft, deep layer shear is low, and organization will be loose. No strong storms are anticipated. Any convective activity will be rapidly moving out and winding down as we approach 00z. Saturday is looking dry and warm, but breezy. Model guidance is consistent in showing 25-35 mph wind gusts during the afternoon and evening hours. We can`t rule out wind gusts approaching 40 mph especially across west central Lower MI, particularly near Lake MI. This is supported by Bufkit cross sections using the NAM and GFS. We don`t have to mix very high to obtain the 30-35 kt winds...only 1000 ft or so. Finally, there is a low probability of remnant MCS activity to impact areas near and north of US 10 early Sunday morning. Most likely any storms that develop across northern Wisconsin into the U.P. will be fading as we approach 12z Sunday, in spite of the MUCAPE axis shifting into central Lower MI by that time. Still a low chance that this region may get clipped by a few showers and storms. Sunday afternoon, a 25-30 kt LLJ core will be oriented across central Wisconsin stretching into central and northern Lower MI. SBCAPE of 1000 J/kg or more will develop especially across central Lower MI Sunday afternoon and evening. This area is also closer to a weak H500 shortwave impulse moving over the cusp of the ridge that will be establishing itself. Low POPs are warranted for this area, though it seems like the bulk of the thunderstorms will be further north. .LONG TERM...(Monday through Friday) Issued at 314 PM EDT Fri Jun 9 2017 The last prolonged heat wave of note in GRR/LAN area was from July 15 through the 19th 2013, when Grand Rapids highs were at or above 90 degrees for 6 days from the 14th through the 19th. It was at or above 95 degree on 4 of those 6 day. In Lansing it was similar 5 days at or above 90 and 3 days with highs of 94. Battle Creek, Kalamazoo, and Jackson`s numbers were very much like Lansing during the July 2013 heat wave. All had 5 days with highs of 90 or higher from the 15th through the 19th. My point is I can seriously see most of the area near and south of I-96 and inland of US-31 having highs in the lower to mid 90s from Sunday through Wednesday. If this happens it will not exceed the last heat wave in July 2013 (June and July of 2012 had more extreme heat waves in this area) but it will be our longest and hottest since 2013. The models continue to show the lead Pacific storm (one of 3) coming on shore on Saturday. That results in an omega block from the dateline to western United States. With that upper low over the western CONUS, a large upstream ridge builds over the eastern CONUS. Meanwhile a polar vortex looking feature develops over Hudson Bay. This will create quiet the baroclinic zone along the Canadian Board where the Canadian Polar Air air meets the subtropical air. It is there where all the convection should be from Sun through Tuesday, or really Wednesday afternoon. Finally the next of the large Pacific storms (storm 2) boots the first system east and shears it out over the eastern upper ridge. Typically the models do this too fast and weaken the system too quickly. I am thinking the associated cold front will be slower and stronger. That means we would still be in the heat Wednesday and would not get the convection with the cold front till Wednesday night or Thursday. One of the aspects of why I think it will be so hot is it has been rather dry over a large part of our area since early May. With the high solar angle, there is little in the way of water to evaporate from the soil to heat it. I believe this is part of the reason our forecast highs have been running 4 to 8 degrees to cold day after day for nearly 2 week now. Also I believe the convection with the front will be near and north of route 10 and with a largely westerly wind at mid to upper levels we will not be seeing a lot of MCS cloud debris most of this time either. Finally in the Thursday time frame that closed upper low shears out enough to bring cooler Pacific air into Michigan. Since we could be seeing a stretched, slow moving front we could be looking at several days of thunderstorms Thu into Fri or even Saturday. We will likely any cool below normal till at least early in the following week. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1130 PM EDT Fri Jun 9 2017 VFR conditions will continue at all the terminals through Saturday evening. South to southwest winds will increase significantly from mid to late Saturday morning through the afternoon and early evening gusting and gust to near 30 kts at times Saturday afternoon. Wind speeds will diminish to around 10-15 kts by mid evening Saturday and remain out of the south to southwest. && .MARINE... Issued at 943 PM EDT Fri Jun 9 2017 Issued a Beach Hazard Advisory earlier for Saturday, for the coastal counties bordering the Gale Warning. Earlier discussion below. Upgraded the SCA from Holland to Manistee to a Gale Warning. Bufkit soundings support 35 kts or greater especially across the northern half of this region, but gales are certainly possible as far south as Holland given the southerly flow rapidly strengthening over the lake. Saturday afternoon looks rough with large waves building into the 4 to 7 foot range or greater, especially near and north of Holland. These rough waters will persist into Sunday morning. && .HYDROLOGY... Issued at 1249 PM EDT Fri Jun 9 2017 Scattered showers resulted in very little measurable rainfall last night. Most reports came in under five-hundredths of an inch. Additional showers and thunderstorms could develop today, mainly east of Grand Rapids. Localized, brief periods of heavy rain could develop, but should not have much of an impact on rivers. Given recent dry weather and near normal stream flows, flooding concerns are nil at this point. The weekend continues to look mainly dry with a storm track focused north of Grand Rapids. Portions of central Lower Michigan could see rain chances increase Sunday night. However, the nighttime mode of convection is relatively hard to capture with exact timing/placement. Any variability could make a notable difference in resulting precipitation amounts. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Beach Hazards Statement from Saturday afternoon through late Saturday night for MIZ037-043-050-056. LM...Gale Warning from noon Saturday to 5 AM EDT Sunday for LMZ846>849. Small Craft Advisory from noon Saturday to 5 AM EDT Sunday for LMZ844-845. && $$ UPDATE...Meade SYNOPSIS...Hoving SHORT TERM...Hoving LONG TERM...WDM AVIATION...Laurens HYDROLOGY...JAM MARINE...Meade
Area Forecast Discussion
National Weather Service Mount Holly NJ
935 PM EDT Fri Jun 9 2017 .SYNOPSIS... High pressure located over the western North Atlantic is forecast to influence our weather into Tuesday. A cold front from the north is expected to pass through our region on Tuesday night. High pressure is anticipated to build from eastern Canada to the waters off New England on Wednesday and Thursday. A warm front approaching from the southwest is expected to arrive on Thursday night or Friday. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Weak trough at both the surface and aloft lies along the East Coast and is moving offshore. Low pressure currently over the Great Lakes continues to track east and will move into western NY/PA. Clouds associated with this low will increase and thicken tonight. That low moves into central NY by daybreak Saturday, and isolated to scattered showers and thunderstorms are then possible in the pre-dawn hours on Saturday for far northern and western zones, generally along and north of I-78. Several hours ago the HRRR was rather bullish on shower coverage and intensity. However, over the last few runs it has fallen in line with the other mesoscale models. A lower coverage of any showers/ thunder associated with the system makes sense given the dry airmass currently. The timeframe for any precipitation will likely be just after sunrise. Lows tonight will be considerably warmer tonight in the 50`s outside of the Philly region. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... Low pressure over central NY continues to track to the east during the day Saturday and departs by early evening. A frontal boundary will trail behind the low and will pass through the region as a warm front in the afternoon. Isolated to scattered showers and thunderstorms possible across areas mainly to the north of I-95 through the day. Downsloping westerly flow will help turn temperatures much warmer on Saturday. Highs will be in the upper 70s across the Poconos, otherwise in the low to mid 80s across NW NJ and into the Lehigh Valley. For the rest of southern NJ, SE PA, and the Delmarva, highs will be in the mid to upper 80s, possibly touching 90 in some spots. Areas right along the shore will be much cooler. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... Ridging at the surface and aloft will likely result in an increase in heat and humidity during the period from Sunday through Tuesday. A developing Bermuda high will cause a very warm and humid southwest flow to develop. We will not issue any Heat Advisories or Excessive Heat Warnings at this time since our region should remain mostly below the criteria. However, we are keeping an eye to Tuesday and our highly urbanized areas for a potential excessive heat/humidity event. A mid level trough is forecast to pass across New York State and New England on Tuesday night and it should push a back door cold front through our region at that time. We will mention either a low or slight chance of showers and thunderstorms. High pressure to our northeast is expected to influence our weather for Wednesday and Thursday with a decrease in both heat and humidity levels. A warm front is anticipated to lift through our region on Thursday night or Friday bringing another chance of showers and thunderstorms. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Overall, VFR conditions tonight and Saturday.A scattered to broken mid-deck is expected around 7,000 feet through the TAF period. The broken conditions are expected to be more prevailing just after sunrise from Philadelphia and points north. A tempo group has been added for VFR showers for RDG and ABE given the possibility of brief precipitation. Any thunder coverage looks far too low for inclusion in the TAFS attm. W to SW winds increase to 5-10 KT late Saturday morning. By afternoon, winds become 10-15 KT with occasional gusts up to 20 KT. OUTLOOK... Saturday night through Monday...Mainly VFR. Monday night and Tuesday...Mainly VFR. There is the possibility of low clouds and reduced visibility during the late night and early morning hours. Tuesday night and Wednesday...Mainly VFR with the possibility of MVFR ceilings on Tuesday night and Wednesday morning along with a low or slight chance of showers and thunderstorms. && .MARINE... Sub-Small Craft Advisory conditions on tap as SW winds will be 10-15 KT tonight through Saturday. Gusts to 20 KT Saturday afternoon. Ocean seas will range from 3-4 feet and seas on DE Bay will be 1-2 feet. OUTLOOK... Saturday night through Wednesday...No marine headlines are anticipated. RIP CURRENTS... A moderate risk for the formation of dangerous rip currents remains in place through Saturday for the New Jersey coastline. This is mainly due to the proximity to the full moon and gusty winds in the afternoon. The risk is lower for Delaware. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ Synopsis...Iovino Near Term...Gaines/MPS Short Term...MPS Long Term...Iovino Aviation...Gaines/Iovino/MPS Marine...Iovino/MPS
Area Forecast Discussion
National Weather Service San Diego CA
151 PM PDT Fri Jun 9 2017 .SYNOPSIS... A trough of low pressure will bring cooler weather along with extensive clouds west of the mountains this weekend. Strong winds are expected each afternoon and evening in parts of the mountains and deserts. High pressure will bring fair weather, less coastal cloudiness and a gradual warming trend next week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... This afternoon, skies are mostly clear except for a few marine layer clouds at the immediate coast of south San Diego County. A few cumulus have also developed over the mtn peaks courtesy of daytime heating mixing out the boundary layer. Chances are good that the low clouds spread inland again tonight, although they may be less well organized. A low pressure trough over the West will increase the onshore flow and strengthen winds through mountain passes and into parts of the deserts each afternoon and evening through Sunday. Sunday afternoon/evening is likely to be the windiest period, with Isolated gusts exceeding 45 mph in wind-prone areas like the San Gorgonio Pass, however most gusts will remain below that over most of the deserts. The marine layer will deepen, but the cold air associated with the trough will serve to weaken the marine inversion and produce better mixing of the boundary layer. That will mean extensive low clouds filling the coastal basin and moving up the mountain slopes, but probably not full or uniform cloud coverage. The clouds don`t appear thick enough for any precip until Saturday night when just enough energy could produce drizzle or even light rain. The influx of cooler air associated with the trough will make it unseasonably cool this weekend. Sunday`s high temps will be from 5 to 20 degrees below average. On Monday, the trough moves to the northeast and the marine layer will become shallower. Slowly building high pressure next week will bring a gradual warming trend. The marine layer will rebuild much shallower so that coastal clouds are restricted to areas near the coast and only during nights and mornings. Each day will be warmer than the previous day with temps across the region rising to above average by Thursday. It could get pretty hot inland next weekend or temps could be closer to seasonal averages, depending on which model verifies better. && .AVIATION... 092009Z...Coast/Valleys...Through 10/0000 UTC, primarily P6SM vis and FEW clouds AOA 20000 ft msl. 10/0000-1500 UTC, OVC stratus re- developing and filling the coast and valleys, with bases 1500-2200 ft msl, tops around 2500 ft msl, and areas of vis 3-5 sm over the valleys. Forecast confidence is moderate. Mountains/Deserts...P6SM vis and FEW clouds AOA 20000 ft msl through Saturday morning. After 10/0000 UTC, W winds 15-25 kt with gusts 35 kt over mountain ridges, desert slopes, through passes and into wind- favored adjacent deserts will create mod-stg uddfs/llws over and E of the mountains. && .MARINE... A trough will be moving inland along the U.S. West coast through Monday which will result in an increase in northwesterly winds. HRRR shows wind gusts to increase into the 20-25 KT range beyond 20 nm off the coast late this afternoon through this evening. A Small Craft Advisory is in effect through Midnight tonight. Winds relax a tad overnight into Saturday before picking back up again late Saturday and then strengthening further Sunday into early Monday when another advisory for hazardous small craft conditions may be needed for the outer waters. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory until midnight PDT tonight FOR Waters from San Mateo point to the Mexican Border Extending 30 to 60 nm out including San Clemente Island. && $$ PUBLIC...PG AVIATION/MARINE...Harrison