Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/22/18

National Weather Service Eureka CA
253 PM PDT Sat Jul 21 2018 .SYNOPSIS...Temperatures will not be quite so hot across the interior valleys this weekend, before returning closer to 100 degrees for the upcoming week. Cooler weather with areas of marine stratus will be found along the coast, especially south of Cape Mendocino. Isolated thunderstorms will impact areas around Trinity County on Sunday. && .DISCUSSION...Heat and thunderstorm activity over the interior along with areas of smoke, haze and coastal stratus will continue to be the forecast challenges...none of which are terribly out of the ordinary for northwest California in late July. Approaching 2 pm PDT, a look at the visible satellite reveals mostly clear skies across the bulk of the interior, with smoke and haze across Del Norte and mainly northwest portions of Humboldt County. Webcams along the Redwood coast show mainly clear but hazy skies. Coastal stratus has been persistent along the vast majority of the coast near and south of Cape Mendocino thus far today. Light winds there are tending southerly and onshore, with a coastal eddy circulating a continued supply of stratus up from offshore of Point Arena. These coastal clouds and fog may keep the Mendocino coast cloudy for much of the next couple of days, and will try to begin to peel around Cape Mendocino into Humboldt Bay tonight. Expect with northerly winds still offshore and adjacent to the north side of Cape Mendocino, the bulk of the stratus shield may struggle to make headway. Still think there will be a bit more cloudiness along the Humboldt coast later tonight into Sunday morning, perhaps filling in and thickening along the entire Redwood coast by Sunday night. Meanwhile, the switch to more southerly low-level flow, albeit still very light, should tend to shift some of the smoke out of our area, as indicated by the HRRR model. However, expect areas closest to the Nachez fire around Del Norte county to remain hazy tomorrow. Otherwise, the focus will shift to a threat of thunderstorms over eastern and northeastern Trinity County on Sunday afternoon. The models have generally seemed a little bit too aggressive with mid-level moisture and instability thus far, though there is some sign of that in ACCAS to our southeast, as close as Napa county. Models indicate much more in the way of instability and anomalous precipitable water values tomorrow as this mid-level monsoonal moisture settles in across our area. However, mid-level lapse rates look fairly poor, with limited shear and forcing under a strong mid/upper-level ridge of high pressure. The consensus of guidance points toward a couple storms firing up around the Trinity Alps or perhaps Trinity Center, but for the above reasons, am doubting the storms get very strong or are more than isolated coverage-wise. Better chances will exist out of our area, into Siskiyou county. Heat will continue to be an ongoing concern for the interior, though this weekend is giving us a relative break, with just mid 80s to mid 90s for most. High pressure ridging over the southwestern United States will build through the middle of the upcoming week, with the hottest interior valleys 100-105 by Wednesday. There are few signs of any real relief in this hot pattern for the foreseeable future. && .AVIATION...All terminals have been experiencing VFR conditions early this afternoon. Smoke from the wildfires to the north continue to produce a broken to overcast layer at around 4000 ft with slight visibility reductions at the surface as well. HRRR smoke guidance indicates smoke should remain entrenched across interior Del Norte County this evening and through tomorrow however smoke impacts at ACV may begin to lessen. The other forecast concern is the persistent stratus that has remained south of Cape Mendocino so far today. Model guidance has been struggling with the stratus which places low confidence in their solutions for tonight and tomorrow morning. However, northerly winds continue to decrease as we go through the afternoon which should allow stratus to begin to round the cape late this afternoon or evening. Southerly winds are expected to strengthen along the entire coast by tomorrow morning which means that low clouds and reduced visibilities can be expected at ACV and CEC at the latest by late tomorrow morning. Clear skies will continue to prevail at UKI during this cycle. Cumulus clouds will be on the increase along the interior mountains this afternoon which may increase turbulence. /WCI && .MARINE...The surface thermal trough will continue to pivot across the Southern waters. As a result, northerly winds will continue to decrease as we go through the afternoon and into the evening. Winds will remain elevated across the northern outer waters where gale gusts will remain possible through this evening. Near the coast, southerly winds will begin to strengthen late tonight and into tomorrow morning to around 5 to 15 kts. Seas across the outer waters and northern inner waters will remain steep and hazardous through Sunday afternoon. Northerly winds will begin to increase again by the middle of next week. /WCI && .FIRE WEATHER...There may still be a small area of northeast Del Norte county with enhanced northeast winds tonight, but overall trends will be better, with lighter winds, and higher RH values. Temperatures will continue to be hot through the upcoming week, albiet a little bit of repreive for today and Sunday from the above 100-degree readings. Isolated thunderstorms will be an issue around northeastern Trinity County on Sunday, but do not expect abundant lightning at this time, with more concerns in that department farther north and northeast into Siskiyou county. Thus have held off on any Red Flag Warnings, but will continue to highlight isolated lightning in the FWF. See the above discussion section fore some more forecast reasoning. Might not be able to completely rule out a stray shower or weak storm around the Trinity Alps Monday or Tuesday afternoon, but otherwise it looks like the week ahead will be mostly storm- free. && .EKA WATCHES/WARNINGS/ADVISORIES... CA...None. NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory until 3 AM PDT Sunday for PZZ450. Gale Warning until 9 PM PDT this evening for PZZ470. Small Craft Advisory until 3 PM PDT Sunday for PZZ475. && $$ Visit us at Follow us on Facebook and Twitter at: For forecast zone information see the forecast zone map online:
Area Forecast Discussion
National Weather Service Glasgow MT
916 PM MDT Sat Jul 21 2018 .DISCUSSION... Showers and storms have been ongoing this evening in central MT and are beginning to move into our western zones. HRRR, HiRES NMM, and RAP all pick up on this rainfall and thunder (so do the GFS & Euro to some extent), so made adjustments accordingly to bring rain and thunder through the CWA overnight tonight. By tomorrow afternoon, it should be a sunny, dry, and breezy day across the area. Avery Previous discussion... Most of the forecast challenges and focus remained on the ongoing severe thunderstorms pummeling our Daniels, Sheridan, and Roosevelt Counties this afternoon and evening. Tried to blend current conditions with the best model data consensus. Large hail, and frequent lightning seem to be the predominant threats. Those severe thunderstorms will diminish and move east into North Dakota later tonight. The frontal system responsible for this series of supercells is drawing in hot moist air from the southeast ahead of the front with cooler, drier are coming in behind the front from the west and northwest later overnight and through all day Sunday. Those winds on Sunday will be strong enough to justify having issued another Lake Wind Advisory through all day Sunday. Overall forecast thereafter will follow a drier and cooler pattern with high temperatures barely reaching into the 80s. The upper level low pressure system responsible for this cooler weather pattern will keep the hot high pressure from the south dampened down through all of next week. A return to hotter temperatures may be possible as the western states high pressure ridge rebounds through next weekend. BMickelson && .AVIATION... Flight Category: VFR, but some visibility reduction is possible near active rain showers and thunderstorms through the morning hours. Synopsis: Showers and some thunderstorms will move across the region overnight tonight, moving east of the forecast area by Sunday afternoon. Winds: Should be out of the northwest on Sunday between 15 to 25 kts with higher gusts at times. Avery && .FIRE WEATHER... A few showers and thunderstorms are possible in the west overnight tonight into Sunday morning, spreading east in the morning and out of the area by the afternoon. Outflow boundaries from Saturday afternoon storms will complicate wind forecasts for overnight tonight in the west. Winds from the ENE have been reported behind the storms, which should subside late tonight. A strong and gusty northwest wind will set in the re-enforcing air mass behind the cold front on Sunday. Expect sustained winds of 20-25 mph and some gusts up to 35 mph. This would blow any remaining fires back toward the already burned area and into the U-L bend of the lake. Avery && .GLASGOW WATCHES/WARNINGS/ADVISORIES... Lake Wind Advisory from 2 AM to 8 PM MDT Sunday For Fort Peck Lake for Central and Southeast Phillips...Central and Southern Valley...Garfield...McCone...Petroleum. && $$
Area Forecast Discussion
National Weather Service Grand Junction CO
547 PM MDT Sat Jul 21 2018 .SHORT TERM...(Tonight through Sunday night) Issued at 348 PM MDT Sat Jul 21 2018 Temperatures are climbing a few degrees more today compared to yesterday with less cloud cover over the region. Lingering moisture and daytime heating are triggering scattered showers and thunderstorms this afternoon across the area, favoring the western Colorado mountains, but these storms will diminish by midnight with the loss of the daytime heating. The HRRR and NAM are showing increased shower activity over the Eastern Uintas beginning tomorrow morning as a short wave begins to cross through the region. Again, the higher terrain across western Colorado will see increased shower activity tomorrow afternoon, although the showers will be more widespread due to the instability introduced with the disturbance passing to the north. Expect a brief break during the overnight hours on Sunday night with slightly cooler lows as heavier cloud cover dissipates. .LONG TERM...(Monday through Saturday) Issued at 348 PM MDT Sat Jul 21 2018 Things begin to become a little more interesting as we head into the new work week. As has been the trend over the last several model runs the area of high pressure is expected to retrograde back into the Four Corners area by late Monday. As this occurs another embedded shortwave will drag across the Continental Divide on Monday, resulting in an uptick in shower and thunderstorm coverage throughout the day. WPC has issued a slight risk for excessive rainfall along this area as precipitable water values once again climb with the passage of the disturbance. If models continue to trend this way Flash Flood Watches may have to be considered for the major burn scars in our forecast area. By daybreak Tuesday the center of the high will be positioned over the northern Arizona/New Mexico border. Drier air will work into the region from the northwest by midweek as the high reaches SoCal. However, moisture will continue to be recycled under the high through the end of the week as daytime heating helps fuel at least isolated orographic convection each day. Temperatures will gradually warm through the long term period as the high builds back over the southwestern CONUS. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 547 PM MDT Sat Jul 21 2018 Expect thunderstorms in the vicinity of KTEX through 02Z with a brief light showers possible along with outflow winds to 25 MPH. Scattered showers and a few embedded thunderstorms will continue across the region this evening, however, with the exception of KTEX, the remaining TAF sites are unlikely to experience this activity directly this evening through midday Sunday. Thunderstorms will bubble up again Sunday afternoon, mainly over higher terrain. Outflow winds could affect TAF sites, however shower/thunderstorm activity are unlikely to impact airfields. Despite moist convective activity, TAF sites can anticipate VFR conditions through the next 24 hours. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...JPF/MMS LONG TERM...MMS AVIATION...NL
Area Forecast Discussion
National Weather Service Goodland KS
538 PM MDT Sat Jul 21 2018 .SHORT TERM...(This afternoon through Monday night) Issued at 115 PM MDT Sat Jul 21 2018 Overview: The Tri-State area will be situated on the N/NE periphery of an upper level ridge (centered over New Mexico), at the southern fringe of NW flow aloft. Today-Tonight: Small amplitude perturbations on/near the tropopause (150-175 mb level) will round the northern periphery of the ridge from the Desert SW/4-Corners region into portions of the Rockies and High Plains this afternoon into tonight. Such subtle/high-altitude features are incredibly difficult to anticipate/track and their `depth of influence` varies depending on the thermodynamic profile -- the more unstable, the greater the influence. Low-level forcing will be confined to shallow convergence invof a weak SFC-H85 trough in the lee of the Rockies and perhaps weak orographic ascent associated with ESE/SE low- level flow. Recent runs of the HRRR and NAM NEST suggest that scattered convection will develop over the mountains/foothills of CO/WY this afternoon with activity gradually growing upscale and propagating E/SE across the Tri-State area this evening (between 01-07Z). Effective deep-layer shear on the order of 25-30 knots and moderate MLCAPE (1000-1500 J/kg) suggest organization will be multicellular in nature. With steep mid-level lapse rates (8C/km) and strong DCAPE, damaging winds /occasional severe downbursts/ will certainly be possible. A broader swath of damaging winds cannot be ruled out given sufficient upscale growth /cold pool consolidation/, particularly in northeast CO where diurnal timing will be more favorable. Expect convection to wane after midnight. Sun-Sun night: With little change in the synoptic pattern, expect conditions to be similar to those today/tonight. Mon-Mon night: Relatively little change in the synoptic pattern compared to today and Sunday. However, with ongoing convection possible over and upstream of the Tri-State area Sunday night into Monday morning, forecast confidence decreases significantly. .LONG TERM...(Tuesday through Saturday) Issued at 128 PM MDT Sat Jul 21 2018 An area of upper high pressure remains over the southwestern CONUS on Tuesday, with ridging across the west and a trough over the eastern portion of the country. This results in northwesterly flow aloft for the region. A closed low advances through Canada midweek and continues north of the Great Lakes region. As the low progresses east, the upper high weakens and retrogrades, centering near Arizona by Saturday. While this pattern unfolds, multiple disturbances travel through the northwest flow with a surface cold front lingering nearby, generating chances for showers and thunderstorms each day during the long term period. Widespread severe weather is not anticipated at this time. However, cannot rule out a few severe thunderstorms during this timeframe with increased shear in place and adequate instability. Good moisture and PWATs of 1 to 1.5 inches also suggest that there is the potential for locally heavy rainfall and flash flooding. Will continue to monitor and pin down details as guidance comes into better agreement in the coming days. Highs are in the 80s throughout the period, excluding Wednesday when temperatures reach the low 90s south of Interstate 70. Low temperatures remain in the upper 50s to low 60s. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 533 PM MDT Sat Jul 21 2018 VFR conditions are expected through the 00Z TAF period at GLD and MCK. Mostly high clouds with light southeast winds are expected at both locations after sunset. TS is possible in the vicinity of GLD between 04-08Z as storms move out of far eastern Colorado and into northwest Kansas. Storms will diminish through the evening as they continue east with TS in the vicinity of MCK between 05-07Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...VINCENT LONG TERM...JBH AVIATION...LOCKHART
Area Forecast Discussion
National Weather Service Wilmington NC
831 PM EDT Sat Jul 21 2018 .SYNOPSIS... Low pressure developing to our west should bring showers and thunderstorms back into the area tonight and Sunday. Next week is shaping up to be very unsettled as low pressure remains across the Southeast and tropical moisture spreads onshore. && .NEAR TERM /THROUGH SUNDAY/... As of 800 PM Saturday...A few light late afternoon/early evening showers popped up along the northern tier of the CWA in an area of surface convergence. This convergence zone will move off to the northeast, and am not expecting any additional convective development until an upstream shortwave crosses the area after midnight. By then, showers and thunderstorms associated with the shortwave will be approaching the Pee Dee region. Although the atmosphere will be stabilizing, it should remain unstable enough to support the potential for weakening convection to make it to the Cape Fear coast by 10-11Z. South of a Wilmington to Florence line, dynamic support will be very weak, and overnight activity may remain somewhat isolated. On Sunday the models are showing drier precipitable of 1.5 inches and as this afternoon the temperatures aloft are cooling to -8 to -10. So will continue with a chance of convection on Sunday. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... As of 300 PM Saturday...Cyclonic flow through most the entire column through the period-certainly not the norm for July. With the center of this deep layer gyre remaining to our west the coastal Carolinas will be in deep layer southerly moist flow. And while these conditions certainly do favor widespread cloud cover and the ever- present chance for rain the axis of deep moisture and specter of heavy rain likely remain just off the coast. Should the mid level trough axis move even slightly westward in future model runs then the coast may once again be under the gun for appreciable rainfall. There is another possibility that some higher QPF could rotate into the area late Monday night. Should the upper low cut off enough from the northern branch trough then deep layer flow could back from S to SSE or SE and fling higher PW into mainly areas-NC moreso than SC. Cloud cover will keep Monday highs below climatology while holding both nights above. && .LONG TERM /TUESDAY THROUGH SATURDAY/... As of 300 PM Saturday...Not a lot of change to the extended forecast and really much wasn`t expected as the guidance has been relatively stable for several cycles now. Mid level low pressure is still expected to linger in the Southeast for a few days with a deep tropical plume/connection funneling into the Carolinas. The GFS appears to open up the low a little quicker Thursday (and the latest ECMWF even moreso) with more of a typical southwest flow aloft, Piedmont Surface Trough setup late Thursday through Saturday. I have increased the pops for Tuesday into early Wednesday to mostly categorical with likely values into Thursday with high chance for the remainder of the period. Temperature forecast remains relatively unchanged with highs in the upper 80s to near 90 trending slightly higher in time with a little less moisture. Overnight lows very stable in the 70s. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... As of 00Z...Lots of uncertainty with respect to convection overnight. The HRRR model has been all over the place and cannot seem to nail down the timing and the severity of the convection. Safe to say there will be some storms after midnight, but may be only isolated. Sunday, upper low will be spinning basically in place to our west, with a dry slot over our CWA. Convection will be isolated in the afternoon, possibly focused on the resultant boundary. Moderate southerly flow is forecast. Extended Outlook...Occasional MVFR to IFR conditions due to scattered SHRA and TSRA through Thursday. && .MARINE... NEAR TERM /THROUGH SUNDAY/... As of 800 PM Saturday...Winds across the waters are generally southwest this evening as a result of a trough of low pressure extending from Norfolk to Fayetteville. THe orientation of the trough won`t change much overnight, and will allow south to southwest winds on the order of 15 knots to continue, with seas running around 4 feet. The winds are expected to become more southerly on Sunday, and the southerly fetch will maintain 3 to 5 ft seas. SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... As of 300 PM Saturday...A Small Craft Advisory will be in effect for the period for NC zones-the headline may not materialize until daytime Monday for SC zones. Low pressure at all levels of the troposphere will be found to our west, which is very uncommon for summertime. Southerly flow will strengthen over the short term and should reach advisory levels as will seas-both seeing a relative delay across southern waters vs. northern waters. LONG TERM /TUESDAY THROUGH THURSDAY/... As of 300 PM Saturday...Southeast winds of 15-20 knots will be in place much of Tuesday into Wednesday. Winds will veer to more south/southwest for the remainder of the period with decent speeds continuing. Elevated seas near Small Craft Advisory criteria will be side by side with the winds with slightly higher values early in the period. && .CLIMATE... As of 330 AM Saturday...Recent heavy rainfall in Wilmington is pushing our 2018 rainfall into record territory. Keep in mind our May rainfall total of 14.36 inches exceeded the next wettest May by over five inches, and January and June totals were also well above normal. The increasing likelihood for an El Nino winter could help make 2018 one of the wettest years ever seen in the Port City. Wettest years in Wilmington`s history, Jan 1 through July 20... #1 48.11 in 2018 #2 45.47 in 1886 #3 44.13 in 1966 #4 39.72 in 1973 #5 38.40 in 1998 && .ILM WATCHES/WARNINGS/ADVISORIES... SC...Beach Hazards Statement from 8 AM EDT Sunday through Sunday evening for SCZ054-056. NC...Beach Hazards Statement from 8 AM EDT Sunday through Sunday evening for NCZ106-108. MARINE...None. && $$ SYNOPSIS...SHK NEAR TERM...DRH/CRM SHORT TERM...MBB LONG TERM...SHK AVIATION...DRH
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1007 PM EDT Sat Jul 21 2018 .SYNOPSIS... Low pressure will move north of the area this evening and tonight. A warm and moist southerly flow between low pressure to the west and high pressure over the Atlantic will produce above normal chances for showers and thunderstorms through midweek as a weak front lingers along the coast. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... As of 1005 pm Saturday...Scattered convection approaching from the west. Kept slight chance in the northeast counties with chance elsewhere. No change to overnight lows. Prev disc...Differences exist later tonight amongst the HRRR, NSSL- WRF and 3km NAM with regards to precipitation development as the NSSL- WRF shows a band of convection moving through the region closer to midnight, while the HRRR and NAM12 show any activity holding off until early Sunday morning. Likely trigger will be a shortwave crossing Kentucky that has become convectively active over the past hour or so. Given the uncertainty in the precipitation timing, have lowered PoPs from likely to high chance from after 03z through the overnight hours. With a record-breaking precipitable water of 2.46 inches from this morning`s 12Z MHX sounding, any convection has the potential to quickly produce heavy rainfall and localized flooding. Low temperatures tonight should be in the low to mid 70s. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... As of 350 PM Saturday...After any initial precipitation in the morning, Sunday afternoon again looks convectively active with deep southerly flow around high pressure offshore with surface trough lingering inland over the Piedmont of North Carolina with mid-level low parked over the Southeastern United States. Following the trends from both the GFS/ECMWF, PoPs go from high chance during the morning to likely during the afternoon. With high precipitable water values, heavy downpours are possible and eastern NC is in a "Marginal" threat of excessive rainfall for Sunday. The deep moisture and widespread cloudiness should reduce the threat for any severe convection Sunday. High temperatures will reach the mid to upper 80s Sunday. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... As of 315 AM Saturday...A warm and moist southerly flow will continue Sunday Night through next week due to low pressure to the west and high pressure over the western Atlantic Ocean, leading to unsettled weather conditions from through much of next week. Sunday Night through Wednesday...Deep, warm, and moist southerly flow will continue behind a departing low pressure system Sunday night and will persist through much of the upcoming week between broad low pressure aloft to the west and western Atlantic high pressure. This pattern is conducive for widespread showers and thunderstorms, most widespread during peak heating with a persistent mid level trough over the eastern US. Timing for the highest chances of rain is roughly Monday afternoon through Wednesday when channeled vorticity sets up over Eastern NC with an elongated axis of very high PWATs stretching from the tropical western Atlantic Ocean. Given persistence amongst guidance over the past several runs, have increased PoPs slightly during this time frame, with the potential for 2 to 6 inches of rainfall, highest closer to the coast. Will continue to highlight severe/flood potential in HWO. Thursday and Friday...The persistent upper trough to our west finally fills and shifts northeast from the Deep South states towards the Mid-Atlantic, with high pressure continuing offshore. Moist southwesterly flow will be present both days with convection more diurnally focused. Temps Sunday Night through Friday will be close to climatological normals, ranging from highs in the upper 80s inland to mid 80s for the coast. Minimum temps will range from the low to mid 70s. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... Short Term /through 18Z Sunday/... As of 635 pm Saturday...All 4 terminals are VFR at present. However, scattered thunderstorms over the western part of the state are moving east and will likely impact the sites later this evening. Sub-VFR expected in scattered storms overnight, and in numerous storms during the day Sunday. Surface winds will be mainly south less than 10 knots. Long Term /Sunday Night through Thursday/... As of 330 AM Saturday...Periodic Sub-VFR conditions are expected through Wednesday as an unsettled pattern develops across Eastern NC. Southerly flow will continue Sunday night and will last through next week. && .MARINE... Short Term /Tonight and Sunday/... As of 1005 pm Saturday...Current marine zones still look good. No changes needed late this evening. Gusty southwest winds will continue overnight with rough seas persisting through the evening before subsiding somewhat after midnight. While conditions may subside for several hours late tonight and early Sunday, have extended the Small Craft Advisory from tonight through later this week, and wind and seas quickly increase again by late morning to midday on Sunday. With high pressure offshore and a surface trough over the Piedmont of North Carolina remaining in place for much of the next several days, gusty southerly winds and rough seas will continue. Did extend the SCA for the Pamlico Sound until 5 AM Sunday morning, but conditions there should subside below SCA status for at least a day or so. Long Term /Sunday Night through Thursday/... As of 330 AM Saturday...Low end SCA conditions are expected over the waters for much of the period. Sunday Night through Wednesday, moderate S/SW winds 10-20 kt develop between low pressure well west of the waters and high pressure across the western Atlantic Ocean, producing 4 to 6 ft seas, highest for the outer fringes of the coastal waters. While boating conditions will be poor for most of the period, conditions will be exacerbated by a prolonged period of showers and thunderstorms from approximately Monday afternoon through Wednesday. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...Small Craft Advisory until 6 AM EDT Sunday for AMZ135. Small Craft Advisory until 9 PM EDT Thursday for AMZ150-152- 154-156-158. && $$ SYNOPSIS...CTC NEAR TERM...HSA/CTC SHORT TERM...CTC LONG TERM...DAG AVIATION...HSA/MS/DAG MARINE...HSA/CTC/DAG
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1101 PM CDT Sat Jul 21 2018 .SHORT TERM...(This evening through Sunday) Issued at 345 PM CDT Sat Jul 21 2018 This afternoon, the Upper Midwest was caught between an anomalous upper low across the Great Lakes-Ohio Valley, and an upper ridge over the high plains of Montana and western North Dakota. Deep layer moisture has been abundant in the eastern 1/4 of MPX forecast area of west central Wisconsin due to the persistent wrap around of the moisture associated with the upper low. Mid level lapse rates are weak in this area of west central Wisconsin, but at least enough to generate a few diurnally driven showers or storms through the early evening. Elsewhere over the Upper Midwest, very dry mid levels will keep this area dry through Sunday afternoon. The persistent north/northeast flow in the boundary layer will also lead to an increase in boundary layer moisture across Wisconsin later tonight. This may lead to low stratus/fog building across the area toward sunrise. Sunday will mostly sunny and dry with an increasing southeast wind in western Minnesota in advance of a cold front moving across the Dakotas. .LONG TERM...(Sunday night through Saturday) Issued at 345 PM CDT Sat Jul 21 2018 The pattern will be characterized by an upper high in the southwest that slowly retrogrades, leading to a broad upper low and trough across central and eastern Canada and into the U.S. by mid and late week. Aforementioned ridge over the high plains will shift eastward, and it should extend across Minnesota tomorrow evening. An upper low in western Canada will follow, bringing broad ascent later Sunday night and Monday in the wake of the ridge. Moisture will be abundant, evidenced by the storms developing at this time from Saskatchewan into Wyoming and Colorado. Thus have maintained the chance of storms late Sunday night and Monday across the area. Models are in decent agreement with moving the trough past MN/WI later Monday, so Monday night and Tuesday should be dry. As the Canadian upper low heads for the Great Lakes region Thursday, the next trough will approach Tuesday evening. Cooler air will begin filtering in with northwest flow. Temps aloft drop quite a bit, and this is a pattern typical of scattered showers with a few afternoon/evening thunderstorms as well. Highs Thursday look to be the coolest of the upcoming period, when the upper low is the closest to MN/WI. But even as it moves away into eastern Canada Friday, there should still be some northwest flow and cool enough temps aloft to help promote more showers on Friday afternoon/evening. And again on Saturday. Certainly a pre-fall pattern. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1101 PM CDT Sat Jul 21 2018 Main change from 00z TAFs is stratus in WI is not looking to make it as far west in WI, which means EAU will remain in the clear. It will be VFR through the night, with only a small threat of br/fg at AXN/STC/RWF, but potential is too low to include in the TAFs. With high pressure passing off to the north Sunday, we`ll have light east winds and a few-sct cu field between 3k and 5k feet. During the afternoon, thunderstorms will develop along a cold front in NODAK and will be heading toward AXN by the end of the TAF period. A few of the CAMs show TS reaching AXN as early as 3z, but that thunder will be on a decreasing trend, so will wait until confidence increases on TS evolution into MN before brining any mention in to the TAF. KMSP...At the end of the period, a few of the CAMs are indicating showers may be in the area, with the HRRR being the most aggressive with showing showers in the area as early as 8z. This looks overdone when looking at forcing/instability forecasts, so have kept MSP dry and would be surprised if MSP saw anything at all with this front coming through on Monday. /OUTLOOK FOR KMSP/ Mon...VFR. Slight Chc -TSRA. Wind vrbl bcmg NW 5-10 kts. Tue...VFR. Wind W 5 kts. Wed...VFR. Slight Chc -TSRA. Wind W bcmg NW 10G20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...JLT LONG TERM...TDK AVIATION...MPG
Area Forecast Discussion
National Weather Service New York NY
1057 PM EDT Sat Jul 21 2018 .SYNOPSIS... A potent storm will move up the coast and impact the area, especially late tonight as the associated low pressure center passes to the west. A frontal boundary will remain west of the region through much of the week, with an extended period of unsettled weather with the chance of showers and thunderstorms each day. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Forecast on track this evening with just a few minor adjustments to reflect latest observations. Otherwise, warm core non- tropical low was moving along the Delmarva coast at 01Z. Bands of convection were moving into the northern NJ coast and south of Long Island, some of the cells had very weak rotation, along with some higher wind gusts. Latest HRRR brings a strong wind core with gusts 50-60 kt up to the south shore of NYC and Nassau. So a wind advy continues for western coastal sections for tonight based on that guidance, along with GFS LAMP guidance forecasting advy criteria sustained winds to 30 kt at Bridgeport CT, and close to advy criteria at KJFK. If latest runs of HRRR are correct there is still a chance that the advy for the south shore harbor and ocean locations may have to be upgraded to a high wind warning, especially if winds take on a more SE vs E component. Next concern is rainfall. Operational ECMWF/HRRR have been forecasting heavy rain bands capable of producing a quick 2-3 inches of rain either just west of or straddling our NE NJ counties, also additional similar rain bands run through parts of western Long Island, the lower Hudson Valley, and SW CT. Have higher confidence in the location of the westernmost band but not those farther east, and since their coverage is not widespread and HREF probabilities of 2+ inches of rain was greatest just west of our area, opted against issuing a flash flood watch. Depending on where these bands set up, will most likely have to issue minor flood advisories, but will still have to watch NYC closely for greater impacts to urban infrastructure and possible flash flood warnings to address any direct impact of that magnitude. As these rain bands ride up into Long Island and southern CT, combo of strong 0-1 km shear/SRH and sfc-based instability with SBCAPE approaching 1000 J/kg may be enough to help produce low- topped tstms capable of producing localized damaging winds or a brief tornado. A high rip current risk continues for the ocean waters. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... By daybreak on Sunday, the heaviest rain should lift mainly into eastern CT/Long Island. As tropical moisture continues to stream northward, chances for showers and isolated thunderstorms increase into the afternoon and at night. Temperatures will be near normal or a few degrees below average. A high risk of rip currents is expected for Sunday. && .LONG TERM /MONDAY THROUGH SATURDAY/... Unsettled weather expected for the much of the long term period. An upper level trough and surface front remain nearly stalled west of the CWA as an Atlantic ridge remains offshore. Periods of showers and thunderstorms will remain likely through at least the first part of Monday night, especially west of NYC. POPs then lower on Tuesday and Tuesday night as the upper ridge pushes back to the west. There does remain some uncertainty with this feature and kept probabilities across the eastern zones slight chance and kept chance probabilities to the west of NYC. An upper level low moving across central Canada on Wednesday slides into the Great Lakes region by Thursday night. This will push the trough and front closer to the region, with POPs increasing once again through this period. Its nearly impossible this far out to time any showers and/or thunderstorms and will keep at least some 50% chance POPs in the forecast. The trough and front cross the region during the Thursday night/Friday morning timeframe with drier weather expected for Friday. There may still be some lingering precipitation, so will continue to maintain some low chance POPs. A tropical like airmass will remain in place next week with highs each day in the 80s and lows mostly lower to mid 70s. Humidity levels remain uncomfortable with dew points in the lower to mid 70s. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Low pressure over eastern Maryland at 02Z was beginning to track just to the west of north and will continue to move to the northwest overnight, moving to the west of the area terminals. A warm front moves into the terminals late in the overnight and lifts to the north Sunday. During Sunday the low weakens and tracks into the eastern Great Lakes region. Easterly winds and gusts will increase, with sustained to around 20 KT, and occasionally as high as 25 KT, with gusts increasing up to 35 KT. The highest winds and gusts are expected to the at the coast terminals, especially KJFK and KISP terminals. Ceilings have lowered to IFR and MVFR and will remain IFR overnight. Visibilities will also lower to IFR especially in moderate to heavy rain and isolated thunderstorms, as the warm front draws closer to the region. So will continue with the tempo from 04Z to 10Z. LLWS wind shear is likely overnight with a E to SE low-level jet, strongest at the coastal terminals. By Sunday morning, south/southeast winds prevail, with gusts at times in the 20 to 30 kt range. MVFR ceilings are likely, with scattered showers expected through the end of the forecast period, 00Z Monday. There may be a brief period of VFR conditions, especially in the afternoon. .OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY... .Sunday night...Mostly MVFR with a chance of IFR in SHRA and isolated TSTMs. .Monday-Thursday...MVFR/VFR with periods of SHRA and a chance of TSTMs. S gusts 20-25 kt. && .MARINE... Gale warning remains up for all waters tonight as the coastal storm works its way up the coast, with sustained winds 25-35 kt and gusts 35-45 kt expected. There is a chance that winds on the western ocean waters and New York Harbor may be quite a bit stronger than this, and that this warning may have to be upgraded to a storm warning. Will be watching coastal obs along/off the Delmarva and Jersey shore for guidance on this potential. Gales should subside Sunday morning as a strong southerly LLJ shifts east of those waters, with elevated seas continuing. Winds will remain below SCA levels on the forecast waters Sunday night through Wednesday. However, with a prolonged southerly flow and southerly swells, ocean seas will remain at SCA levels through Tuesday. Seas may briefly fall below 5 ft Tuesday night into Wednesday, but SCA seas then return for Wednesday night and Thursday. && .HYDROLOGY... Rainfall of 1-2 inches is likely in most areas from late tonight into Sunday morning. Locally higher amounts are possible, especially in any heavier or more persistent rain bands. Minor urban and poor drainage flooding looks to be the main threat. A flash flood threat does exist, but not at high enough probability to warrant issuance of flash flood watches. This may change as the coastal storm works its way closer to the area and radar obs lend confidence on exact location of heavier rain bands overnight. A prolonged period of unsettled weather is expected through the upcoming week, with the chance of showers and thunderstorms each day. The focus of higher rainfall amounts are expected along a frontal boundary setting up inland. && .TIDES/COASTAL FLOODING... While astronomical tides remain low with the full moon still a week off, strong E-SE winds should result in surge of 2-3 feet, high enough to yield brief minor coastal flooding in some locations in/around the NY Bight, including the south shore of Staten Island and the back bays of southern NYC and southern Nassau. The south shore of Staten Island may be more susceptible to flooding as strong E winds and shape of the coastline pile up water in Raritan Bay. A coastal flood statement has been issued for the overnight/early Sunday morning high tide cycle along the south shore from NYC to southern Nassau county. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Wind Advisory until 6 AM EDT Sunday for CTZ009. NY...Wind Advisory until 6 AM EDT Sunday for NYZ072>075-080-176-178- 179. Wind Advisory until 6 AM EDT Sunday for NYZ071-078-177. High Rip Current Risk from 6 AM EDT Sunday through Sunday evening for NYZ075-080-081-178-179. NJ...Wind Advisory until 6 AM EDT Sunday for NJZ006. MARINE...Gale Warning until 6 AM EDT Sunday for ANZ330-335-338-340-345- 350-353-355. && $$
Area Forecast Discussion
National Weather Service Portland OR
258 PM PDT Sat Jul 21 2018 .SYNOPSIS...An upper level trough will move east of the area this evening. In it`s wake, high pressure aloft will expand northward from the Great Basin over the next several days. This coupled with a thermal trough at the surface will bring several days of very warm temperatures at all inland locations. The coastal region will be cooler with near seasonable temperatures. && .SHORT TERM...Tonight through Tuesday. Satellite imagery this afternoon shows clear and sunny weather over the region. The main message for the next several days is hot weather expected over the inland areas. The coast will be the place to be to stay out of the heat with seasonal temperatures of 60s to low 70s. Temperatures will begin to climb on Sunday with valley high temperatures in the low 90s. Inland high temperatures on Monday will increase 5 degrees above Sunday`s readings with upper 90s expected both Monday and Tuesday. We should see some overnight relief on Sunday night as lows dip into the 50s Monday morning. However, there will not be much relief Monday night as overnight lows will only drop into the 60s around sunrise Tuesday morning. With very warm temperatures expected Monday and Tuesday, we opted to issue an Excessive Heat Watch for Mon and Tues. It`s worth noting that 90 degree temperatures over the inland area swill be with us most of the week, which is 8 to 10 degrees above normal. The other item to note is the possibility of some transport of smoke from the wildfires in southwest Oregon into the Lane County Cascades and foothills Sunday afternoon and evening. The HRRR smoke model indicates some transport of smoke Sunday afternoon as the steering flow becomes southerly. /tw .LONG TERM...Tuesday night through Saturday...Warm, dry weather continues through the week. Inland temperatures near 90 will be common through the week, while the coast remains pleasant in the 60s and 70s. A little relief from the heat is possible toward the end of the week as a weak trough clips the area from the north. /tw && .AVIATION...A low level northwesterly flow pattern under building upper level high pressure tonight and Sunday will lead to primarily VFR conditions areawide through 00z Monday. The main exception to this will be along the coast where there is a chance LIFR/IFR conditions could briefly develop along portions of the coastline between ~09-15z Sunday, but suspect most of the coast will remain VFR given NE winds at 925 & 975mb should keep marine clouds and fog offshore during this time. KPDX AND APPROACHES...A northwesterly low level flow pattern under building high pressure aloft will lead to primarily VFR conditions through 00z Monday. /Neuman && .MARINE...High pressure over the northeast Pacific and thermal low pressure over southwestern Oregon will result in a fairly typical summer-time northerly wind pattern for much of the next week. Expect wind gusts of 25 kt across the central Oregon waters through tonight across the inner waters and into the first half of Sunday across the outer waters. Do not think steep and hazardous seas criteria will be met, but it`s not impossible either. Otherwise, winds and seas look to remain mostly below advisory thresholds during the upcoming week across our waters except across the central Oregon waters from time to time when northerly winds may temporarily spike up to 25 kt during the afternoon and evening hours. /Neuman && .PQR WATCHES/WARNINGS/ADVISORIES... OR...Excessive Heat Watch from Monday morning through Tuesday evening for Central Columbia River Gorge-Central Willamette Valley-Greater Portland Metro Area-Lower Columbia-South Willamette Valley-Upper Hood River Valley- Western Columbia River Gorge. WA...Excessive Heat Watch from Monday morning through Tuesday evening for Central Columbia River Gorge-Greater Vancouver Area-I-5 Corridor in Cowlitz County-Western Columbia River Gorge. PZ...Small Craft Advisory for winds until 3 PM PDT Sunday for Waters from Cascade Head to Florence OR from 10 to 60 NM. Small Craft Advisory for winds until 3 AM PDT Sunday for Coastal waters from Cascade Head to Florence OR out 10 NM. && $$ Interact with us via social media: This discussion is for Northwest Oregon and Southwest Washington from the Cascade crest to 60 nautical miles offshore. This area is commonly referred to as the CWA or forecast area.
Area Forecast Discussion...UPDATED
National Weather Service Tampa Bay Ruskin FL
815 PM EDT Sat Jul 21 2018 .UPDATE... A weakening MCS pushed through the northern portion of the area this afternoon producing some gusty winds across the Nature Coast. At the present time, just a few light showers remain across Highlands and Charlotte counties but most spots are currently dry under mostly cloudy skies. For the overnight, forecast is a bit tricky as its difficult to determine if the aforementioned MCS remnants have stabilized the northeast Gulf enough to impact any nocturnal/morning showers activity from Tampa northward that we would typically expect with the mid/upper level pattern in place across the region. Recent runs of the HRRR keep much of the area dry overnight but with deep moisture in place and favorable dynamics feel its prudent to at least keep some mention of PoPs in the forecast areawide overnight. Current forecast has a handle on things well so no changes made at this time for the evening update. That being said, forecast remains tricky and showers and storms could develop at any time so additional updates could be needed over the next few hours. Overnight conditions will be quite warm and muggy with coastal locations not getting out of the 80s with some mid and upper 70s expected inland. && .AVIATION... VFR expected outside of any showers and storms. Southwest to west winds are expected overnight around 5 to 10 knots. Winds will increase during the day Sunday in the 10-15 kt range with higher gusts likely. Showers and storms will be possible at any time with moist SW flow regime so localized MVFR/IFR reductions can be expected in and around storms. && .MARINE... Elevated winds and choppy seas will be the rule through the rest of the weekend and into early next week. Winds are expected to increase tonight to near cautionary levels across much of the forecast waters out of the west...and remain at or above 15 knots into Monday. Conditions will also favor scattered to numerous showers and storms. && .Preliminary Point Temps/PoPs... TPA 81 89 80 88 / 30 40 40 60 FMY 79 91 80 90 / 50 60 40 60 GIF 77 92 78 89 / 20 60 30 60 SRQ 81 88 82 88 / 30 50 40 60 BKV 79 90 77 89 / 30 60 50 50 SPG 80 90 80 89 / 30 40 40 60 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through Sunday evening for Coastal Charlotte-Coastal Hillsborough-Coastal Lee-Coastal Manatee-Coastal Sarasota-Pinellas. Beach Hazards Statement through Monday evening for Coastal Charlotte-Coastal Sarasota. Gulf waters...None. && $$ UPDATE/AVIATION/MARINE...11/McKaughan UPPER AIR...19/Hurt DECISION SUPPORT...69/Close