Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/16/17

Area Forecast Discussion
National Weather Service Gaylord MI
1145 PM EDT Sun Oct 15 2017 .UPDATE... Issued at 1042 PM EDT Sun Oct 15 2017 Conditions really quieting down this evening, with winds becoming rather light and minimal shower activity. Upstream largely moisture starved wave will arrive during the early morning, perhaps kicking off a few more lake induced showers. Not a big deal for sure. Temperatures will continue their slow descent, bottoming out well into the 30s across interior areas, with just a bit warmer readings near the big waters. && .NEAR TERM...(Tonight through Monday) Issued at 329 PM EDT Sun Oct 15 2017 ...Cool but quieting down... High impact weather potential...winds diminishing quickly this evening. 993mb surface low is quickly scooting eastward across southern Quebec. The associated cold front has exited MI. Final area of wraparound synoptic precip is pushing across central/eastern portions of northern MI, and will exit over the next few hours. Some lake enhanced showers are noted upstream on MQT radar. In general, our wx is quieting down during the near term period, with wind and precip trends the primary concern. Winds have not lived up to their billing today. Gusts to around 35mph are relatively common, but we are struggling to get much more than that. Expect winds to remain relatively steady state thru 6 pm or so, with a very rapid falloff as we hit dusk and beyond. Per coord with GRR/DTX, will cancel the wind advisory a bit early. As mentioned above, widespread rain will exit to the east before sunset. We are plenty unstable enough for lake effect, with 850mb temps -2 to -4c. But inversion heights are dropping below 5k ft this evening, with plenty of dry air above that. This should make it difficult to get more than spotty showers. Rap runs have generally been pretty dry for the 1st half of the night, and then spit out some QPF south of TVC after 2 am. Will have some slight chance to sct pops in western Chip Co, nw lower MI, and between Rogers City and APN. Is there a chance to get something besides rain? Perhaps, though the modified marine layer will make that a challenge. Still, a few snowflakes could sneak in overnight, especially in western Chip Co. Will stretch slight chance pops into Monday morning in parts of nw Chip Co and nw lower MI. Otherwise, 1000-850mb winds will be backing and 850mb warm advection will develop. That will eliminate any lake- induced precip. Diurnal heating in the chilly and marine-moistened airmass will contribute to substantial cu/stratocu by afternoon. Min temps tonight mainly in the 30s, around 40f along the nw lower MI coast. Max temps Monday primarily in the mid 50s. && .SHORT TERM...(Monday night through Wednesday) Issued at 329 PM EDT Sun Oct 15 2017 ...Moderating temperatures... High Impact Weather Potential: None. Pattern Forecast: By Monday night, a mid level wave and attendant surface reflection are expected to be crossing the northern Ontario/ Hudson Bay region with high pressure anchored over the Ohio Valley. Northern Michigan will lie in somewhat of a transition zone with ongoing warm air advection expected to continue right through the middle of the week. Primary Forecast Concerns/Challenges: Little in the way of sensible weather; however, occasionally gusty winds (not nearly as strong as Sunday) are possible at various times through midweek. As aforementioned low pressure over Ontario passes by to our north, occasionally gusty winds are expected Monday night...especially over the waters of the Great Lakes. Gustiness continues early Tuesday as ongoing warm air advection aids to boost temperatures several degrees warmer than Monday. High temps anticipated to top out in the low-mid 60s area-wide Tuesday, although it`ll feel cooler than that with wind gusts approaching 20 mph midday into the afternoon. A similar story is expected Wednesday with another, more potent, wave passing through southern Canada. High pressure anchored to the south should yield another precip-free day under partly to mostly sunny skies locally, but again may feature a bit of midday and afternoon gustiness as a tighter gradient sags in from the north. High temps another few degrees warmer...ranging from the low-mid 60s north and from 65-70 degrees south of the bridge. .LONG TERM...(Wednesday night through Sunday) Issued at 329 PM EDT Sun Oct 15 2017 High pressure over the eastern CONUS will bring a rather quiet extended period. Warming temperatures will once again be the main story heading into the weekend. Highs over the weekend are expected to be 10 to 20 degrees above normal. A cold front approaching the area early next week will bring the next chance for rain. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1144 PM EDT Sun Oct 15 2017 Lake effect clouds and a few light showers expected to continue tonight, although conditions are expected to remain mostly VFR. More shallow VFR producing cumulus/strato-cu expected to develop again later this morning and afternoon. Winds become light tonight, increasing in speed some out of the west later today. && .MARINE... Issued at 329 PM EDT Sun Oct 15 2017 Low pressure is rapidly heading east across Quebec. Pressure gradient will relax rapidly, especially after sunset. Gale force gusts are still seen occasionally, but those should transition to small craft advisories this evening. West to sw winds will ramp up again late Monday and especially Monday night, and additional advisories will be needed by then. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY until 5 AM EDT Monday for LHZ347>349. LM...SMALL CRAFT ADVISORY until 5 AM EDT Monday for LMZ323-342- 344>346. LS...SMALL CRAFT ADVISORY until 5 AM EDT Monday for LSZ321. && $$ UPDATE...MB NEAR TERM...JZ SHORT TERM...MG LONG TERM...AM AVIATION...MB MARINE...JZ
Area Forecast Discussion
National Weather Service Taunton MA
1032 PM EDT Sun Oct 15 2017 .SYNOPSIS... A strong cold front sweeps across the region overnight and will bring scattered showers into early Monday morning. Behind the front, it turns sharply cooler and brisk Monday afternoon with temperatures dropping down close to freezing by daybreak Tuesday. Gradual warm up through the week, possibly into the weekend, while overall dry and quiet with scattered cloud decks and breezy winds from time to time. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 1015 PM Update... Line of showers continues progress SE out of NY state, reaching the northern Berkshires at 02Z. Noting gusty SW winds along the southern near shore waters. Gusts up to 32 kt at KEWB, 34 kt at KFMH and 32 kt at KPVC, with a peak wind of 35 kt at KPYM and 31 kt at KCQX. Also noting gusts to around 30 kt across portions of E Mass into RI, so very good low level mixing continues this evening. Noting the showers ahead and along the approaching cold front have been tending to slowly weaken, but bands of stronger reflectivity still seen. Short range and high res models do continue the trend of weakening this line further as it crosses the region overnight. Near term forecast pretty much on track so far with temps mainly in the mid-upper 60s across the region, which will remain steady through around 06Z or so, then will fall pretty quickly as the cold front pushes across through the remainder of the night. Previous Discussion... As the fine-line progresses E there less instability to work with. However riding the cold front along and ahead of which the activity is maintaining is stout. A very fine thermal discontinuity met with a decent pressure couplet as discerned from the latest SPC / high- res mesoanalysis. A lot of frontogenetical convergence along the line that with heavier precipitation outcomes coupled with both the isallobaric and gradient winds is lending to mechanical mix-down of very fast westerly winds, in excess of 40 mph observed over the E Great Lakes Region. Some question as to the inversion over our region and a limited threat, however RAP sounding profiles highlight that along the front the inversion is somewhat eroded. In all, the expectation is for the fine-line to weaken, but closely keeping an eye give the associated synoptics. Expect the cold front to sweep across after midnight, and could see winds amplify with a brief period of 35 to 45 mph gusts, more likely behind the cold front out of the W/NW. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... Monday... A few left over showers will be possible across the far SE New England coast during the first part of Monday morning. Otherwise, expect some strato-cumulus to work into the region in the cool advection pattern but will also see some peeks of sunshine. Temperatures late Monday morning and afternoon will mainly be in the upper 50s to the lower 60s, but a bit cooler in the higher terrain. Northwest wind gusts of 20 to 30 mph will make it feel chilly compared to our recent mild weather. Monday night... High pressure will build in from the west allowing winds to gradually diminish, except across the southeast New England coast. Cool airmass in place should allow overnight low temps to drop to around 30 to the lower 30s in the normally coolest outlying locations. Some frost/freeze headlines will likely be needed where the growing season is technically still in place. Lastly, it will be milder across the Cape/Nantucket as NNW winds will result in ocean effect cloudiness and holding low temps in the 40s. 850T to seas surface temperature differential around 20C may even yield an isolated shower or two. && .LONG TERM /TUESDAY THROUGH SUNDAY/... */ Highlights... - Gradual warm-up through the week into the weekend - Perhaps a pattern change into late October, more active, cooler */ Overview and Discussion... Change is on the horizon. A deeper polar low upstream shifting from the Siberian Peninsula E into Alaska diminishes downshearing storm development over the W CONUS and rather promotes ridging into late October. Concurrent with a strong MJO phase 4/5/6 signal, and the expectation is for mild, moist Pacific air to pump into the W CONUS ahead of deep troughing over the NE Pacific. Meanwhile this also promotes downshear deeper troughing over the E CONUS. But prior to, as the polar low matures E into Alaska, individual upstream Pacific origin waves continue to slam into the Cascades later emerging downstream and undergoing cyclogenesis NE into Canada. High pressure is promoted over the SE CONUS beneath preferred H5 ridging. Subsequent SW pump of warmer air across the Central into E CONUS as far N/E into NE Canada. Looking at a suppressed environment over S New England. Aside from a series of weak frontal passages concurrent with breezy winds, Tuesday night into Wednesday, and again Thursday night into Friday with light shower activity over N New England high terrain, otherwise little to no wet-weather activity given abundant dry air through the following weekend. Main story is the warming temperature trend for late October beginning near- seasonable with highs around the low to mid 60s warming into the 70s, possibly into the 80s by the weekend. Consensus of model guidance preferred which signals the low to mid level high situated over the SE CONUS out to Bermuda round which the heat pump flows, breaking down early next week as Pacific energy shears off into the SW CONUS as high pressure builds around the coast of CA. The pattern flips and troughing becomes promoted into the NE CONUS. Looking at the next cold frontal passage and chance of wet weather potentially beginning around Monday night into Tuesday. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Monday Night/...High confidence. Overnight... MVFR-IFR CIGS linger over SE terminals, with SCT-BKN clouds around 2-3Kft elsewhere. Mainly VFR VSBYS across the region. SW wind gusts up to 30 to briefly 35 kt along the S coast, Cape Cod and the islands and 20-30 kt elsewhere. Expect winds to quickly shift to W-NW with the frontal passage. Could see brief gusts up to around 35 kt or so with the front. A line of SCT SHRA will push across the terminals ahead of the cold front which should push offshore by around 09Z or so. Monday... SCT SHRA ending. SW winds turning W/NW. CIGs improving, BKN to SCT low-end VFR. Low risk MVFR early. Gusts around 20 to 25 kts. Monday night... VFR other than perhaps a period of some marginal MVFR ocean effect clouds across the Cape/ACK. Winds diminish for most but NW wind gusts of 20 to 25 knots continue for Cape/Islands. KBOS Terminal...Strongest winds developing and likely to continue towards midnight. Already gusts in excess of 30 kts. Will push higher around 35 kts for tonight. KBDL Terminal...SW wind gusts increasing. Expect strongest winds at the beginning of the TAF period going into midnight. Monitoring the fine-line W which will move into the terminal close to 10p behind which winds revert NW continuing into the early morning hours Monday, remaining gusty but around 20 kts. Outlook /Tuesday through Friday/...Moderate confidence. Tuesday through Friday... VFR. W winds. Breezy at times, around late Tuesday and again late Thursday && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Monday Night/...High confidence. Overnight... SW winds gusting up to 25-30 kt will continue overnight, with brief gale force gusts across the southern near shore waters especially Buzzards Bay, Vineyard Sound and Nantucket Sound as well as the eastern open waters through around midnight. Small crafts continued for all waters. Scattered showers move across the waters after 06Z or so with the cold front. Winds quickly shift to W-NW with the frontal passage mainly across the eastern waters around 07Z-09Z Monday and Monday night... Behind the sweeping cold front, NW gusts 20 to 30 kts, close to near gale force, especially over the open waters. Strongest winds immediately behind the front and then into Monday night given colder air aloft building S over the warm waters. SMALL CRAFT ADVISORIES continue and may need to be extended. Outlook /Tuesday through Friday/...Moderate confidence. Overall W winds, breezy at times around late Tuesday and again late Thursday. Waves for the most part below 5 feet, only issues worth noting are on the S/SE outer waters early Tuesday, possibly again Thursday night into Friday. Otherwise good boating weather. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until noon EDT Monday for ANZ231>235-237- 251. Small Craft Advisory until 8 AM EDT Monday for ANZ230-236. Small Craft Advisory until 8 AM EDT Tuesday for ANZ250-254>256. && $$ SYNOPSIS...Frank/Sipprell NEAR TERM...Sipprell/EVT SHORT TERM...Frank LONG TERM...Sipprell AVIATION...Frank/Sipprell/EVT MARINE...Frank/Sipprell/EVT
Area Forecast Discussion
National Weather Service Charleston SC
942 PM EDT Sun Oct 15 2017 .SYNOPSIS... High pressure will weaken tonight into Monday. A strong cold front will move through the region Monday evening. High pressure will then build into the region and will prevail through next weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... The forecast is on track and only required minor adjustments. The latest NARRE-TL (Time-lagged North America Rapid Refresh Ensemble System) has increased the probabilities for dense fog to 80-90% from Walterboro to near Beaufort east across much of the Charleston Tri-County area 09-12z Monday. Have introduced some dense fog wording into the grids and text forecasts in this area given this trend. The primary forecast concern for the overnight period once again centers on the potential for fog development. Forecast soundings show a nearly identical airmass to 24 hours ago, but the flow atop the boundary layer is forecast to be weaker than what was experienced this morning. Should see a combination of fog and low stratus develop during early Monday morning with conditions favoring areas roughly along and east of the I-95 corridor for the better chances for dense fog. In fact, vsby output most of the high resolution models for the past several runs now show an increasing potential for widespread fog with vsbys 1/4 mile or less in the 3-9 am time period, so confidence is increasing that a Dense Fog Advisory may be needed for some areas later tonight. RAP wind fields do show 1000 hPa winds increasing to about 10-15 kt in the Reidsville-Allendale corridor after 09z in response to the approach of a cold front and a thickening mid- level cloud deck, so this may limit the fog coverage there and support a bit more in the way of low stratus. For this update, will continue to highlight "areas of fog" for all but the Reidsville-Allendale corridor where "patchy fog" will be placed. Lows from the mid 60s interior Southeast Georgia to the lower 70s at the coast look on track. Expect mainly dry conditions to prevail through daybreak Monday. Isolated showers are likely to develop over the coastal waters in the vicinity of a weak land breeze circulation that moves offshore later tonight. A band of showers will also likely be approaching the far western zones by 6 am. Latest guidance suggests this will likely remain out of the far western zones prior to sunrise. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... Monday: An amplifying, positively tilted upper shortwave trough will advance toward the region Monday and will cross the region Monday night/Tuesday. This trough will drive the strongest cold front thus far this season through the region late Monday into Monday evening. While isolated showers/thunderstorms could precede the front, the axis of deepest moisture/best precipitation will reside along/north of the boundary. Also, a weak wave could develop along the front, and the 850 mb front will lag behind the surface boundary. This anafront scenario suggests that best precipitation coverage featuring numerous/widespread showers and isolated thunderstorms will push through the region Monday afternoon/evening, a few hours slower than previous forecasts. The latest forecast indicates likely POPs with timing adjusted to indicate later timing. Higher POPs and additional timing adjustments to perhaps delayer higher POPs early then extend higher POPs deeper into Monday evening could eventually be needed. Monday night through Wednesday: The axis of deep-layered moisture will push south/east and will eventually push out of most/all areas Monday night. Showers will linger longest across southern coastal counties. Meanwhile, high pressure will then push much cooler air into the region, supporting lows in the 50s most areas and 60s along the GA coast due to onshore winds. Tuesday, temps will only top out in the lower/mid 70s most areas, followed by mid/upper 70s Wednesday. Tuesday night, temperatures will range from the upper 40s well inland to the lower 60s on the GA coast where onshore flow will continue. Also of note, long fetch northeast flow produced by high pressure will push Atlantic moisture onshore especially across southern counties, supporting isolated/scattered showers especially along the GA coast. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A large surface high will yield dry weather and gradually warming temperatures through the end of the week. A few showers are possible over the coastal waters, possibly brushing immediate coastal areas at times. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... Primary concerns: * Fog/low-stratus with IFR or lower conditions * Timing of showers/tstms with a strong cold front Biggest near term concern is for IFR or lower conditions associate with fog and low-stratus early Monday. Confidence is increasing that impacts will occur at both terminals. Fog conditions look the most favorable at KCHS where dense fog could occur for a few hours prior to daybreak and lingering to the mid-morning hours. Seeing a fairly uniform dense fog pattern in the various high resolution guidance which increases confidence. Will continue to trend conditions down at both KCHS and KSAV. For KCHS, will show vsbys and cigs right at airfield minimums at KCHS (1/2SM FG and OVC002) in a TEMPO group from roughly 10-13z, but lower conditions, including prevailing 1/4SM FG VV001 can not be ruled out. For KSAV, slightly less mid-level over the boundary layer could prevent conditions from cratering there. Will limit vsbys to 2SM (right at alternate minimum thresholds and not establish a cig, but show SCT002. It is still very possible that lower conditions will occur. A strong cold front will cross the terminal late afternoon Monday bringing a few hours of showers/tstms. Will show prevailing MVFR vsbys in moderate rains for now from 20-24z at KCHS and 21-24z at KSAV. Will not include a mention of TSRA just yet as there remains some instability uncertainties. Extended Aviation Outlook: Brief flight restrictions possible Monday afternoon into Monday evening especially within showers/isolated tstms. VFR later Monday night through Thursday. && .MARINE... There are increasing concerns that fog, possibly dense, could impact the Charleston Harbor and nearby Atlantic waters out 10 nm Monday morning. Added "areas of fog" to these zones to account for this possibility. A Marine Dense Fog Advisory may be needed. The coastal trough well offshore is forecast to weaken overnight while the strong cold front upstream is expected to reaches upstate SC and north GA late. Weak onshore winds late this afternoon will become light and variable overnight. There will still be some lingering 2-3 ft swells and these should make up most of the wave component overnight. Seas 4-5 ft close to the Gulf stream over our far outer GA waters should subside to 3-4 ft with time. Focus centers on significant cold air advection and associated hazardous wind/sea event expected to commence late Monday/Monday evening and continuing to some degree into Thursday. A strong cold front will cross the waters from north/northwest to south/southeast late Monday into Monday evening. In the wake of cold fropa, strong north/northeast winds will surge into the waters, and seas will build quickly. Then, strong high pressure will build from the north, and a tight surface pressure gradient and a mixed marine layer tapping into elevated winds aloft will maintain elevated winds/seas through the middle of this week. Winds will gradually diminish around the middle of the week, but elevated seas will persist into Thursday across near shore waters and beyond across the outer GA waters. Due in part to the prevalence of at least 35 knot winds within the 950-925 mb layer and the likelihood for a deeper marine mixed layer near the west wall of the Gulf Stream, raised a Gale Watch for AMZ374 valid Monday evening into Tuesday afternoon. Then, SCA conditions should persist across the outer GA waters into at least late week. Across near shore waters, confidence is high in a solid Small Craft Advisory event starting late Monday/Monday evening and continuing into Thursday to account for persist 6 ft seas. However, due to some uncertainty regarding timing and magnitude of stronger winds for Charleston Harbor, opted not to issue an SCA here to allow later shifts to assess updated guidance. && .TIDES/COASTAL FLOODING... Strong/persistent northeast winds will push higher water levels to the coast this week. Minor coastal flooding will be possible around the times of high tide beginning Tuesday morning and continuing into Thursday. Coastal Flood Advisories could eventually be needed. && .EQUIPMENT... Hourly observations and daily climate data from the weather sensor along Riley Waterfront Park (KCXM) in Downtown Charleston will not be available until further notice. The cause of the senor outage is unknown at this time. Technicians will assess the equipment on Monday. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory from 6 PM Monday to 5 PM EDT Thursday for AMZ352. Gale Watch from Monday evening through Tuesday afternoon for AMZ374. Small Craft Advisory from 5 PM Monday to 5 PM EDT Thursday for AMZ350. Small Craft Advisory from 7 PM Monday to 5 PM EDT Thursday for AMZ354. && $$
Area Forecast Discussion
National Weather Service State College PA
1159 PM EDT Sun Oct 15 2017 .SYNOPSIS... A strong cold front will push through the region tonight. Blustery and cool weather is in store for Monday. Temperatures will rebound to near normal on Tuesday, then continue to gradually rise to well above normal right into this upcoming weekend, as a large area of high pressure builds east over Ohio Valley and Mid Atlantic states bringing an extended period of dry conditions. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... The cold front extends from just east of Wellsville NY down to between Indiana and Johnstown. A narrow cold frontal rain band is just out ahead of the and is causing briefly gusty winds and rainshowers. The HRRR shows the line continuing quickly SE while diminishing in intensity as cooler air begins to downslope into the forecast area. QPF should be on the low side, a tenth of an inch or less in most areas where the rain moves through this evening. After the front clears the area this evening, the cold NW flow will make quite a dramatic difference in the temps, and especially the apparent temps considering a brisk breeze from the WNW overnight. After being so warm, the drop to much below normal temps and cold cross-lake flow...strato cu and sprinkles/light showers will be a shock. Min temps early Monday will vary from the U30s to L40s across the NW mtns and Laurel Highlands, to the lower 50s in the SE. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... For Monday, we expect to see maxes about 5-10F below normal with highs ranging from the U40s to L50s across the mtns, to around 60F in the SE. As the mid-level thermal trough crosses the region Monday, isolated to scattered instability (and lake effect) showers will occur across the NW Mtns and Laurel Highlands, with just some sprinkles accompanying expanding MDT cu clouds in the afternoon elsewhere. The NW wind gusting between 20-25 mph will trim another 8-10 degrees off what the air temp should feel like on our skin. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... As the upper level trough deepens as it moves eastward, cold air, with readings of around 6C at 850 mb will move over the region by Tuesday morning. Temperatures will be slightly below normal with readings in the mid 30s. Frost across much of Central and Northern PA remains likely with even sub- freezing conditions across the perennial cold spots INVOF KBFD. For the mid to late week period, heights gradually rise with a multi-model consensus indicating a string of dry and increasingly warm days and mainly clear/cool nights. We could have a period true Indian Summer weather with high temps in the in the low to mid 70s from mid week into next weekend. && .AVIATION /04Z MONDAY THROUGH FRIDAY/... A strong cold front has pushed southeast of the entire region as of late this evening. In the wake of the front, low level moisture ascending the western mountains should produce predominantly MVFR cigs at KBFD and KJST the rest of the night into Monday morning. Elsewhere, the drying effect of a downsloping northwest flow should result in predominantly VFR conditions through tonight. High pressure will build into the region Monday, bringing clearing skies and gusty northwest winds. Model soundings indicate lingering MVFR cigs at KBFD/KJST will give way VFR conditions by around 16Z. Outlook... Tue-Wed...Patchy AM fog possible. Thu...No sig wx expected. Fri...Patchy AM fog possible. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte/Lambert NEAR TERM...La Corte/Lambert SHORT TERM...Lambert LONG TERM...Ceru AVIATION...Fitzgerald
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
341 PM PDT Sun Oct 15 2017 .UPDATE...Updated air quality issues. && .SYNOPSIS...Above normal temperatures through Wednesday with a significant cooling trend Thursday into the weekend. Showers will be possible across much of the area Thursday through Friday. && .DISCUSSION...Upper level high pressure over the desert southwest began to build northwest into southern and central California resulting in a warming trend. Temperatures this afternoon were generally between 6 and 9 degrees warmer compared to 24 hours ago and are forecast to warm to around 5 degrees above normal for the middle of October. Continued warming is expected on Monday...which also looks to be the warmest day of the week...with daytime high temepratures climbing to nearly 10 degrees above normal. Above normal temperatures will prevail across the area into Wednesday. Breezy offshore winds were present this afternoon across the Kern County mountains as well as near the Grapevine...where wind gusts between 20 and 25 mph were observed. The strongest winds were right near the Grapevine today...where gusts to 44 mph were observed this morning and this afternoon. The HRRR has been consistently advertising that winds will subside in the next few hours. Otherwise...the focus of the forecast shifts from warm and dry to cool and possibly wet Thursday into Friday as an upper trough begins to impact the Pacific Northwest and northern California coastline on Thursday. The best chance for precipitation across the area will be from Fresno county northward Thursday evening into Friday. Snow levels with the bulk of precipitation will generally hover between 9000 and 10000 feet. Yesterday afternoon the forecast models indicated that the entire region would see precipitation...where today those same models are keeping the bulk of the precipitation from Fresno county northward. We will continue to closely watch model trends over the next 24 and 48 hours and hopefully nail down timing as well as amounts of precipitation expected. Either way...we are confident that the entire region will see a significant much as 20 degrees between Monday and Friday. Another thing to note...NCEPs Global Ensemble has decreased predictability in the upper level pattern for Thursday and Friday compared to 24 hours ago...adding to our uncertainty in the extended forecast. Please continue to monitor the forecast for the latest information. && .AVIATION... Areas of MVFR visibilities due to smoke can be expected in the San Joaquin Valley, foothills and higher elevations of the Sierra Nevada for at least the next 24 hours, with VFR conditions prevailing elsewhere across the Central California Interior. && .AIR QUALITY ISSUES... Please see SFOAQAHNX for an Air Quality Alert. On Monday October 16 2017... Unhealthy for sensitive groups in Kern County. Further information is available at && .CERTAINTY... The level of certainty for days 1 and 2 is high. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit for additional information an/or to provide feedback. && .HNX Watches/Warnings/Advisories... Red Flag Warning until 6 PM PDT this evening CAZ295. Wind Advisory until 5 PM PDT this afternoon CAZ095. Wind Advisory until 5 PM PDT this afternoon CAZ091-092. && $$ public...Riley avn/fw...BSO synopsis...Riley
Area Forecast Discussion
National Weather Service Jackson MS
910 PM CDT Sun Oct 15 2017 .UPDATE... Updated for evening discussion. && .DISCUSSION... Scattered showers and isolated storms continue this evening as a cold front moves through the region. Precip should end later tonight, with lows ranging from the mid 40s north to around 60 southeast. As for the current forecast, increased evening pops for most locations and added thunder in the south for this evening. No other changes were needed. /27/ Prior discussion below: Tonight and Monday: Latest RAP and satellite imagery showed a strong upper trough moving through the mid section of the CONUS. This was dragging a cold front toward the region from the northwest. Area radars were picking up warm advection showers and isolated thunderstorms. Readings across the region were in the lower to middle 80s. For tonight, the front will swing through the region for late this afternoon through tonight. The rains will decrease from the northwest in the wake of the front. The showers will end across our southeast counties prior to dawn. A more seasonably cool airmass will infiltrate the region with lows in the upper 40s north to the lower 60s southeast. For Monday, sunny skies and cool below normal readings will be the general rule with highs from the upper 60s to the lower 70s. The surface high pressure will build across the region from the northwest as the upper trough swings across the region./17/ Monday night through Saturday: Light cold air advection will continue Monday night as the pressure gradient remains tight between surface high pressure ridge over the TN valley and the cold front along the coast. Still, expect mins to fall into the 40s given the dryness of the airmass. A slow warming trend will get underway Tuesday as mid level heights begin rising from the west. Shortwave ridge looks to develop over the Southern Plains by midweek and will result in surface temps climbing back into the lower 80s by Thursday. Surface ridge will remain anchored over the southeast states with east/northeast winds keeping the air dry. The increasing warmth by mid to late week with the airmass remaining dry may begin to promote some afternoon fire risks. However, winds look to remain weak. Will continue to monitor this potential in future forecasts. By Saturday, the surface ridge will have pushed far enough south to begin pushing low level moisture back into the area from the Gulf of Mexico. The mid level ridge will also have pushed east of the area allowing PWs to increase to around 1.75 over western portions by Saturday afternoon. These conditions should promote at least slight chance pops over the southwest quarter./26/ && .AVIATION... 00Z TAF discussion: Adjustments were made to ceilings/weather for this evening based on frontal timing trends, but expect VFR conditions to return quickly along with gusty northerly winds through Monday following the front, which is expected to move through the entire area by late tonight. /EC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 52 72 46 74 / 30 0 1 1 Meridian 55 72 47 74 / 47 2 1 1 Vicksburg 51 72 45 75 / 52 0 1 1 Hattiesburg 61 72 48 75 / 40 9 1 1 Natchez 52 71 46 74 / 31 1 1 1 Greenville 48 71 44 74 / 25 0 1 1 Greenwood 48 71 44 74 / 47 0 1 1 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$
National Weather Service Jackson KY
1019 PM EDT Sun Oct 15 2017 .UPDATE... Issued at 1019 PM EDT SUN OCT 15 2017 Cold front has cleared eastern Kentucky. However, the H850 trough is only about 125 miles behind the surface front, following close behind and now moving to the southeast across our area. This feature is kicking off a second band of showers which is currently moving across our southwestern zones. HRRR has picked up on this new development and brings it east-northeast across the southeastern half of our forecast area over the next several hours, though weakening with time. Consequently had to adjust PoPs to account for this activity. Also made adjustments to the temps and dew points as the cooler, drier air appears to be moving in more rapidly than originally forecast, again the result of the H850 trough which is typically a useful feature for timing the more credible cooler and drier air into some given region. UPDATE Issued at 759 PM EDT SUN OCT 15 2017 Strong, fast moving cold front is a little more than half way through the forecast area. Expectations are that it will exit eastern Kentucky between 9 and 10 p.m. this evening. Winds along and just behind the front have been gusting as high as 40-45 mph through the late afternoon and early evening. But there seems to have been a decreasing trend over the last hour or so. There has also been some isolated thunder through the evening as well. But the threat of thunder should end in the next hour or so. Frontal boundary will continue to push east overnight as northwesterly winds gradually drop off. Clouds will also linger until closer to dawn. Adjusted PoPs, sfc temps and dew points for the early evening update, mainly in an attempt to better capture changes in sensible elements associated with the frontal zone as it pushes across the area. && .SHORT TERM...(This evening through Monday night) Issued at 317 PM EDT SUN OCT 15 2017 A broken line of showers well ahead of the approaching cold front is moving across the area. The lack of instability has limited the strength of the convection, but instability is a little greater in the southwest part of the area where 18Z SPC mesoanalysis has CAPE over 1000 j/kg. Some lightning has shown up southwest of the forecast area in far northern TN near the KY border so will continue to carry a slight chance of thunder for the next few hours. Other scattered showers are near the front which has passed SDF and CVG. There are some gusty winds with the front with a peak wind of 36 knots at CVG and 39 knots at SDF. The front will move quickly southeast across the area late this afternoon and early evening and be southeast of KY by around 00Z. The shower chance will diminish quickly after the frontal passage and much cooler air will spread into the area. While fog will likely limit frost formation Monday night, there may still be some scattered frost in some areas. .LONG TERM...(Tuesday through Sunday) Issued at 317 PM EDT SUN OCT 15 2017 There is good model agreement with the evolution of the overall upper level flow across the United States during the coming week. Initially there will be weak troughing in the east, and weak ridging over the southwest U.S. This will transition to a slightly wavy zonal flow, but by the end of the week as troughing develops in the west, upper ridging will build in the east. Overall this means an extended period of dry weather for us, with warming temperatures. At the beginning of the period we will still be under the influence of the cool air mass which will overspread the area Sunday night, and frost remains a possibility in a few spots Wednesday morning. However on Tuesday the surface high will begin a gradual shift to the east and this will combine with a building upper level ridge late in the week to bring a warming trend, with temperatures well above normal by the end of the week. Very warm weather will continue through next weekend with readings around 10 degrees above normal. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) ISSUED AT 759 PM EDT SUN OCT 15 2017 Strong, fast moving cold front is a little more than half way through the forecast area. Expectations are that it will exit eastern Kentucky between 9 and 10 p.m. this evening. Winds along and just behind the front have been gusting as high as 40-45 mph through the late afternoon and early evening. But there seems to have been a decreasing trend over the last hour or so. There has also been some isolated thunder through the evening as well. But the threat of thunder should end in the next hour or so. Frontal boundary will continue to push east overnight as northwesterly winds gradually drop off to around 5 kts and shower activity comes to an end. Generally MVFR CIGS will linger until around dawn. Northwest winds will increase again as diurnal effects kick in, generally about 10 kts. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...RAY SHORT TERM...SBH LONG TERM...SBH AVIATION...RAY
Area Forecast Discussion
National Weather Service Mount Holly NJ
927 PM EDT Sun Oct 15 2017 .SYNOPSIS... A cold front will progress to the east and move through our region later tonight. High pressure is then expected to settle over the eastern part of the country for the period from Monday through Sunday. There may be a weak cold frontal passage Thursday night. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 930 pm update: Cold front continues to blast eastward across the Northeast this evening. Objective 01Z surface analysis shows the front positioned from a 991-mb surface low near the Quebec/New Brunswick border to near Burlington, VT, to near Altoona, PA with very strong 3-hour pressure rises continuing upstream of the front/low. Front should reach the western CWA within 2 to 3 hours. Thin line of low- topped convection is slowly diminishing along the front, but there has been increasing lift and precipitation echoes (albeit quite light) upstream of the band recently. As synoptic- scale lift increases via upper-jet dynamics and differential cyclonic vorticity advection downstream of a potent vort max in the Great Lakes region, more light rain/showers should develop just behind the front. Latest HRRR and NAM Nest are quite consistent with this signal, especially southeast of the I-78 corridor, late tonight. Current PoP/Wx grids look OK for now, though they still might be timed a little on the fast side. Main changes to the grids were more edits to winds/sky cover given latest trends (finally some clearing in the area) and to increase dew points in the pre-frontal regime. Portions of previous discussion included below... Subjective 22Z surface analysis indicates a 992-mb surface low in far southeastern Quebec with a trailing cold front near Watertown, NY, to just west of Pittsburgh with substantial (7-9 mb) 3-hour surface MSLP rises on the upstream side of the front/low. Frontal lift is aiding in the generation of low- topped convection along the front, and with very strong winds aloft, some damaging wind gusts have occurred with the line this afternoon in western NY and northwest PA. This convection will wane rapidly this evening as what little instability is present will nocturnally diminish. However, synoptic-scale lift will get a boost from a strong vort max rapidly progressing eastward through the Ohio Valley and Great Lakes region tonight. Aided by upper-level divergence via the right entrance region of a 250-mb jet streak atop the Mid-Atlantic, post-frontal light precipitation should develop across the area late this evening through early tomorrow morning. The rapid progression of the system and unimpressive vertical profiles of moisture suggest accumulations should be light (generally near or below a tenth of an inch). Winds should turn northwest as the front moves through the area after midnight and may become gusty, especially in the vicinity of showers. The increased winds and continued mixing upstream of the front should hinder a rapid drop in temperatures after frontal passage. Instead, this should just prevent much of a diurnal rise in temperatures tomorrow. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... High pressure will begin to build over the area Monday. Clearing will continue to progress NW to SE over the area. Winds will remain gusty through the day as decent cold air advection continues. Temperatures will mostly remain level or continue a slow fall thru the day. Early highs in the low 60s north and low/mid 60s south/east. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... Hazards...A frost advisory was issued for a small portion of ne PA and nw NJ early Tuesday and coverage may need to be expanded in future forecasts. Additionally... the GFS is flagging potential widespread freeze frost for eastern NJ early Wednesday. Fire weather: please see that section for a brief note on elevated fire danger potential midday and Monday afternoon. 500MB: A short wave crosses New England Monday evening. Another trough passes by, further north across Quebec Tuesday and yet another on Thursday, then very strong ridging (several standard deviations above normal) develops across the Great Lakes and northeast USA late in the week through at least next weekend. Temperatures... October has averaged 8 to 9 degrees above normal for the first 14 days of the month, excluding the ACY Marina where departures from normal are less due to the tempering influence of the nearby ocean (both warm and cold). Calendar day averages Tuesday should be a a couple of degrees below normal, warming Wednesday to nearly 5 degrees above normal, and eventually to daily averages 10 degrees above normal Saturday and Sunday. The daily diurnals will be larger than usual due to the dry airmass in place and light wind fields, nighttime lows probably a little colder than statistically modeled. Forecast basis...This forecast was a 50 50 blend of the 12z/15 GFS/NAM MOS Monday night-Tuesday night, the 12z/15 GFS MEXMOS Wednesday and thereafter the D4-8 WPC 15z/15 12 hourly max/min T and POP, and the 6 hourly td, wind and sky. The very warm GFS D4-8 was not used. The dailies... Monday night...Gusty northwest winds to 20 mph early, otherwise chilling with late night decoupling aiding radiational cooling and the likelihood of scattered to widespread frost near dawn Tuesday, north of I-78, especially near and north of I-80. A frost advisory was issued where temperatures appears to give us the best chance for frost or freezing occurrence. (Isolated frost and freezing temps have already occurred in this advisory area). The gusty north wind may continue all of Monday night along the coasts and there is uncertainty whether there will be enough decoupling s of I-78 to have issued any advisories there at this time. Tuesday-Sunday...Surface high pressure is forecast to build eastward, with its center settling over the Virginias on Tuesday before sliding off the Middle Atlantic coast on Wednesday. The center of the high is anticipated to move back to West Virginia and vicinity for Thursday through Sunday. Our region will remain under the influence of the high through the period. As a result, we are expecting dry weather conditions. This flux of the high pressure centroid may also be associated with a slight temporary cooling Friday with the preceding possible weak cfp Thu night. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Low-confidence forecast tonight. CIGs are beginning to scatter out at PHL/ILG/MIV/ACY, but fluctuations between SCT/BKN from 2000-3000 feet may continue this evening at all sites. CIGs should fill back in, though likely somewhat higher (3000-5000 feet) overnight as a cold front approaches. Scattered showers are likely 03Z to 12Z, with brief sub-VFR VSBYs and somewhat lower CIGs possible. Winds will veer to northwest in the 05Z to 10Z time window with potential for gusty/erratic winds near showers. Skies should rapidly improve after 12Z, but northwest winds will increase to 10 to 15 kts with gusts 20 to 25 kts possible by late morning through the afternoon. Given the low confidence in the CIGs, impacts of showers, and timing of cold front/wind shift...expect several amendments to the TAFs through the overnight hours. OUTLOOK... Monday night through Friday...VFR with mostly a light westerly wind...possibly gusty 15-20 kt Thursday and Friday. && .MARINE... 6:30 pm update: Winds have approached/exceeded advisory criteria at buoy 44009, and are slowly increasing elsewhere. In addition, seas are creeping toward 5 feet across the coastal waters. Current advisory looks good and made no changes to it. Did, however, slow the changeover to northwest winds slightly and slowed the increase in winds this evening to account for the latest observational trends. Previous discussion below... We will keep the SCA flag in place since winds will be increasing as the front nears, and gusty winds will continue after fropa. Scattered showers moving across the waters with the front after midnight and probably mostly done shortly after dawn. Winds mostly SW ahead of the front and turning NW behind it. Fair weather expected Monday. OUTLOOK... Monday night...A Small Craft Advisory is in effect for a northwest wind gusting around 25 to 30 knots. Tuesday..There may be a leftover northerly wind SCA lingering into the early daylight hours on Tuesday. Tuesday night through Friday...No marine headlines are anticipated with generally a westerly flow and gusts under 22 kt. && .FIRE WEATHER... A northwest wind 10 to 20 MPH with gusts around 25 MPH is expected for Monday. Relative humidity values are forecast to drop into the 30s in much of our region on Monday afternoon. Rainfall amounts associated with tonight`s cold frontal passage should be light. As a result, there is a heightened fire weather concern for Monday. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...Frost Advisory from 2 AM to 8 AM EDT Tuesday for PAZ054-055. NJ...Frost Advisory from 2 AM to 8 AM EDT Tuesday for NJZ001-007- 008. DE...None. MD...None. MARINE...Small Craft Advisory until 6 AM EDT Tuesday for ANZ430-431- 450>455. && $$ Synopsis...Drag Near Term...CMS Short Term...O`Hara Long Term...Drag Aviation...CMS/Drag Marine...CMS/Drag Fire Weather...Iovino/O`Hara