Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/29/18

Area Forecast Discussion
National Weather Service Wakefield VA
814 PM EDT Mon May 28 2018 .SYNOPSIS... A weak frontal boundary will linger from central Virginia to the Eastern Shore tonight into Tuesday. The remnant low of Alberto is expected to track west of the mountains through mid week as high pressure remains anchored over the western Atlantic. The moisture ahead of this low will result in unsettled conditions over the area. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 800 PM EDT Monday... Latest wx analysis features a quasi-stationary frontal boundary draped across the northern third of the area (Melfa to RIC to CHO). Per of TS Alberto made landfall near Laguna Beach on the FL Panhandle, with associated moisture is streaming north along the east coast due to a combination of Alberto and high pressure over the wrn Atlantic. Scattered showers and a few tstms have developed mainly along the boundary this aftn along and north of I-64, with any showers/tstms capable of producing very heavy rain, as evidenced by 1.42" at AKQ in less than an hour earlier this aftn. Localized flooding remains possible this evening, even as activity continues to diminish with loss of heating. Meanwhile to the south, an area of rain is tracking across the eastern Tidewater and NE NC associated with mid-level WAA and shortwave energy. This area of rain and perhaps a few embedded tstms will move into SE VA/NE NC through the mid to late evening hours, with additional sct showers expected over central and eastern VA into the early overnight hours. While locally heavy rainfall remains primary threat, have updated to go no higher than slight chc thunder given instability parameters. Will also likely see areas of fog develop over the northern half of the area tonight, with BUFR profiles agreeing with HRRR assessment that best chance will remain over NW corner of the CWA where heavy rainfall occurred, though dense fog is less likely given persistent overcast/mostly cloudy conditions through the night. Warm and humid/muggy tonight with lows in the mid 60s to low 70s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... As of 400 PM EDT Monday... Given Alberto`s remnant low track and the high offshore, models continue to show more of the deeper moisture bands moving N and rotating across the Mid Atlantic region through mid week with the heaviest rainfall across the srn half of the local area. 1.5-2.5" QPF are possible for much of the area (less for the MD Ern Shore), with localized amounts up to 2.5-3.5" through Thursday. The boundary will linger over the region Tuesday, then gradually lift nwd Wednesday, and then N of the area by Thursday. Timing chcs of rain is difficult, so mainly high chc to likely PoPs through the period, but expect showers and embedded tstms to become increasingly diurnally driven through Wednesday/Thursday. The main concern will be locally heavy rainfall and flooding, but confidence is not high enough for a flood watch. Highs both mid 70s/low 80s Tuesday, upper 70s to low 80s Wednesday, and low/mid 80s Thursday. Lows generally in the upper 60s to low 70s. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 410 PM Monday... Medium range period characterized by continued unsettled weather, as the remnants of Alberto lift north and become absorbed by northern stream upper trough over the Great Lakes. EPS/GEFS in reasonably good agreement that this trough then dives south/southeast across the Mid-Atlantic over the weekend, bringing another period scattered to numerous showers and T-storms...mainly the local area into early next week. The associated surface front drops across the area Saturday, and meandering across the region into early next week. Have held rain chances in the high-end chance to likely range by day, with chance pops lingering into the overnight and early morning. Conditions remain warm and muggy through the period. Highs in the 80s, with early morning lows in the mid 60s to low 70s. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 730 PM EDT Monday... A backdoor front continues to reside over the eastern portions of the CWA and widespread tropical moisture continues to move north covering much of the region. TAF sites are bouncing between VFR and IFR conditions depending on the intensity of rain or showers moving through. Overall, am expecting deterioration in conditions through the night as IFR ceilings and visibilities settle in. Winds are mostly light especially over the Piedmont and Central Va so some areas of dense fog possible overnight. Isolated convection may produce some thunder especially over NE NC and SE Va. Rain/drizzle/fog expected through Tue morning with generally IFR conditions slowly improving to MVFR/VFR during the afternoon. Showers and thunderstorms again possible during the afternoon/evening. Outlook: Scattered showers/tstms are possible over the next several days with an influx of tropical moisture from the deep south, along with the potential for late night/early morning stratus. && .MARINE... As of 430 PM EDT Monday... No headlines in the short term tonight thru Wed. Late this aftn, backdoor front was still laying near a Cape Charles westward to York River line. ENE winds 5-15 kt were occurring N of this boundary, while SSW winds 5-15 kt continue S of the line. This boundary will lift north of the area tonight, with winds becoming SE or S. Another backdoor front will drop into/thru the area Tue night and Wed, with wind speeds remaining mainly 15 kt or less. However, seas over the far nrn ocean waters may reach 5 ft by Wed aftn. Sctd tstms could be accompanied by gusty winds through Thu. && .CLIMATE... As of 345 AM EDT Monday... * RIC monthly rainfall total through 5/27 is 10.27" which now ranks as the wettest May on record. (breaking the old record of 9.79" in 2016). (Precipitation records date back to 1880). * SBY monthly rainfall total through 5/27 is 9.66". Through the 27th, this already ranks as the 2nd wettest May on record (wettest is 10.38" in 1948). (Precipitation records date back to 1906). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...AJZ/MAS NEAR TERM...AJZ/MAM SHORT TERM...AJZ/MAS LONG TERM...MAM AVIATION...AJZ/JEF MARINE...TMG CLIMATE...
Area Forecast Discussion
National Weather Service Caribou ME
1049 PM EDT Mon May 28 2018 .SYNOPSIS... A cold front will approach this evening and cross the area overnight. High pressure will build in from the northwest on Tuesday and crest over the area Wednesday. High pressure will move south of the region Wednesday night into Thursday. && .NEAR TERM /THROUGH TUESDAY/... 1030 PM Update... The threat for convection appears to be waning using the latest RAP/HRRR showing the stronger cells weakening as they move into Maine. The 00Z CAR RAOB showed a stable layer of about 3k ft which would aid in suppressing any convection activity. The RAP soundings do show some elevated CAPE of 500 joules around midnight but this looks overdone compared to the latest Near Storm Environment showing at best 200 joules in Quebec. There is still a threat of some heavy rainfall w/the showers expected to move across the region overnight as PWATs are around 1.3 inches. There is moisture up through 700 mbs but this seems to be drying up as the 00Z UA analysis showed 700 mb moisture pushing to the east. There is still some decent shear noted at both 0-3km and 0-6km of 30 kts. So, some wind gusts to 25+ mph are possible in the line of showers later tonight as the front apchs. Adjustments were made to the POPs to take into account the latest radar trends showing the best activity across the northern 1/2 of Maine. Kept the threat for fog across the coast and waters into early Tuesday morning. Previous Discussion... Moisture ahead of a cold front will continue to bring a mostly cloudy sky this evening. Some showers ahead of the front will be scattered across the north and west this evening. Most of the showers are expected to be light and spotty. A cool layer between 3K and 5K feet will prevent any deep convection ahead of the front tonight. The cold front will push across the area during the predawn hours on Tuesday followed by clearing Tuesday morning. Tuesday will then feature bright sunshine with a gusty northwest wind as high pressure pushes down from the northwest. The gradient will weaken Tuesday afternoon allowing the wind to diminish late in the afternoon. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... High pressure will dominate the middle of the week with clr skies and near calm winds expected to build in Tue night as winds decouple. Hv undercut guidance slightly tho may not be cold enuf for mins Wed mrng ovr deeper vly locations. At this time may see patchy frost in far wrn reaches of the St. John Vly bfr daybreak given current fcst lows. Only significance of not drg the rmndr of the short term wl be the warm temps due in on Thur. H9 temps soar to +22C and abv north of the Katahdin region per GFS with latest NAM about 1-2 degrees cooler aloft with CMC the compromise. As a result hv lowered high temps by a degree or two fm prior fcst with max temps drg the day common in the m80s acrs nrn and wrn areas under sw flow aloft. With onshore flow drg the day expected to keep coastal areas cool, relatively speaking, highs wl be hard-pressed to climb into the l/m 70s. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Sfc high wl be building south and out of the area. Upr lvl ridge wl be breaking down Fri morning as wv assoc with Alberto gets captured by trof mvg acrs upr Midwest. CWA shud starting feeling the impacts fm system Fri ngt. Showers shud dvlp Fri mrng in wm sector with airmass destabilizing in the aftn. PW values appch 2 inches Fri aftn and evng, thus hv added in hvy rain with any storms that can dvlp ahd of front. Fropa looks to occur sometime on Sat with GFS mvg it offshore by 18z with CMC slower and EC the compromise. As a result hv included slgt chc thunder for srn zones Sat aftn. With area being in the wmsector Fri night expect to see patchy fog area-wide. In wake of fropa expect hipres to follow into early next week. Latest Euro building 576 ridge acrs the region while rmng med range guidance is flatter with flow. Hv sided with Superblend to retain isold showers thru the end of the pd. Following fropa expect that temps wl return to near normal values, and possibly slightly blo, thru early next week. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... NEAR TERM: Low clouds will result in IFR conditions Downeast this evening followed by an improvement to VFR late tonight. VFR conditions are expected across the north tonight and throughout the area on Tuesday. SHORT TERM: VFR expected through the end of the week with possible tstorms bringing MVFR restrictions on Fri afternoon. Locally hvy rainfall is possible with any storm. && .MARINE... NEAR TERM: Winds and seas are expected to be below SCA tonight and Tuesday. Fog may limit visibilities over the water tonight. The visibility will be good following the cold front early Tuesday morning. SHORT TERM: Seas and winds remain below SCA levels through most of the week. Visibilities may be reduced in fog Fri night through Sat morning before a cold front crosses the waters. May see winds increase to marginal SCA thresholds late Sat night. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && $$ Near Term...Hewitt
Area Forecast Discussion
National Weather Service Cleveland OH
808 PM EDT Mon May 28 2018 .SYNOPSIS... Weak high pressure will remain over the region tonight. Stronger high pressure will build southeast across the Great Lakes tonight and Tuesday. The remnants of Alberto will move north into the central Great Lakes Wednesday, passing just west of the area. && .NEAR TERM /THROUGH TUESDAY NIGHT/... Isolated showers and thunderstorms developed between 3-6PM from Marion east to Stark County and drifted southwest with time. Although hard to see beneath the cirrus, the cu field has thinned and showers have diminished. Some weak surface based convergence remains across NE Ohio but doubt we will see any additional development. Will update to remove the remaining isolated thunderstorm mention in the next hour or so. With high dewpoints remaining across inland NE Ohio will also add a mention of patchy fog from from Millersburg to Canton to Youngstown. Previous discussion... Record heat will continue across the area this afternoon, although dew points have mixed down into the low 60s to upper 50s across parts of the area. Main focus for the rest of this afternoon is potential isolated TSRA roughly along and south of a Marion to Youngstown line. HRRR runs throughout the day have been consistent with developing the isolated convection by 20Z across the area, and latest satellite and radar trends show a few cells trying to develop near Canton. Will hold with the previous iso TSRA mention in the grids through the early evening. High clouds will remain across the area tonight with high pressure over the area. A warm and humid night is expected, with lows only dropping into the mid/upper 60s across the area, and dew points in the low/mid 60s. Some patchy fog cannot be ruled out with light winds, but should mainly be in low lying areas across the southeast part of the forecast area, where dew points have remained in the mid/upper 60s this afternoon at peak mixing. Not anticipating dense fog at this point with the higher clouds streaming north from subtropical storm Alberto, but where convection develops tonight, will need to watch for early fog trends. Tuesday should be a fairly similar day to Monday, with a bit more high clouds expected, as well as some lower/mid level moisture streaming into the region as Alberto makes its way inland toward the Tennessee valley. This should allow for a bit more diurnal cu on Tuesday and dew points remaining a degree or two higher through the day. Will continue to leave slight chance pops in the forecast Tuesday with similar instability to today. Highs are a touch cooler on Tuesday, but most of the area should still reach the upper 80s to low 90s. The remnants of Alberto will continue northward into the southern Great Lakes Tuesday night, passing west of the region. Moisture will increase through the night across the area, but models have backed off a bit timing-wise with precip. Looks like most of the area may remain dry through the night, with just some stray shower activity before Wednesday morning. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... Wednesday begins with low pressure moving north out of over southern Indiana, the remnants of Alberto, with deep, tropical moisture across the Ohio Valley and lower Great Lakes. Do now anticipate a solid shield of rain however diurnal forcing will provide enhancement to the convection with a likely flare up during the day. Best chance will be west closer to the path of the low as it moves north through Indiana, however there will still be a chance of convection across northern PA as well. Will have categorical pops west, likely for the balance of northern Ohio and chance for nwrn PA. Will start out Wednesday night with likely pops everywhere with the low centered in sern lower MI however will drop to chance pops after midnight as focus of forcing shifts north with the low. Thursday the tropical low continues northeast however another low will be approaching from the west across the western lakes. Will boost pops back to likely ahead of this approaching system with leftover tropical moisture still across the area. Friday the system moves through. Will have likely pops east and chance west. temperatures mostly lower 80s Wednesday and Thursday. Highs upper 70s to lower 80s Friday. && .LONG TERM /FRIDAY THROUGH MONDAY/... Although track and timing between the models differ, both models move large upper level trough east of the area and off the East coast Friday night. Will go with chance pops for the area Friday night to cover the lingering showers. AFter that both models have high pressure pushing south across the Lower Great Lakes Saturday for a dry day. After that models diverge. Both models form upper level low from trough on east coast. GFS has the low sliding south along the East Coast with a secondary low tracking into the Ohio Valley. ECMWF on the other hand retrogrades low over the area on Monday. For now will superblend temps and go with low chance pops on Monday. && .AVIATION /00Z Tuesday THROUGH Saturday/... High pressure will remain over the area with winds dropping off to near calm overnight. Although cirrus will continue to move overhead, dewpoints remain high in the mid to upper 60s across inland NE Ohio and could see patchy fog develop after 08Z at CAK/YNG/MFD. Generally expecting patches of MVFR fog but could drop to IFR prior to sunrise so included a 2 hour tempo group. Otherwise fog expected to burn off quickly on Tuesday morning with easterly winds inland and NE winds near the lakeshore. OUTLOOK...NON-VFR possible Wednesday through Thursday. && .MARINE... Light and variable flow will continue across Lake Erie overnight. Tuesday, a weak cold front will drop south across the lake as high pressure moves east through Quebec. Winds behind the front will turn northeast on the lake increasing to 15 to 20 knots west by late afternoon/early evening. Main concern will be for the need for a small craft advisory but for now believe for the most part waves will remain below criteria. With a northeast flow the lake level is also of concern. At this time levels on the west end are expected to get above 5 feet above low water datum Tuesday afternoon/evening but should not get to warning levels of 6 feet. By Wednesday morning winds will veer to the southeast at 15 to 20 knots in response to low pressure moving north through Indiana, the remnants of Alberto. A small craft advisory should not be needed given the southerly wind direction. Flow will turn south Wednesday night and then southwest Thursday as the remnants of Alberto continue northeast and another low moves into the central lakes from the west. The low will continue east of the area by friday afternoon dragging a cold front across the lake. Expecting winds to turn northerly behind the front Friday evening/night around 15 knots. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Greenawalt NEAR TERM...KEC/Greenawalt SHORT TERM...TK LONG TERM...DJB AVIATION...KEC MARINE...TK
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1045 PM EDT Mon May 28 2018 .SYNOPSIS... Deep tropical moisture will persist over the area through Wednesday as the remnants of Alberto move northward from Georgia to Kentucky and eventually to the Great Lakes. A moist airmass will persist into Friday before southerly flow shifts more to the west. Warm yet a little drier air will mix in from the west over the weekend. && .NEAR TERM /THROUGH TUESDAY/... As of 1030 PM EDT...The main rain band from Albert has finally pushed into our GA counties, producing torrential downpours, cg-lightning and a few wind gusts. It has been on a general weakening trend, as we have lost daytime heating and shear is marginal. So while not entirely zero yet, the severe threat looks very low. The latest HRRR takes this band north over the next couple hours and produces some decent simulated reflectivity along the southern escarpment for the post-midnight hours. This may pose some problems with mudslides and flooding overnight for areas that received heavy rain over the last few days. Otherwise, the rest of the forecast area is looking like it may see a lull in flood threat overnight. However, additional heavy rain bands will develop over the area Tuesday. So I will leave the Flash Flood Watch as is. With scattered to overcast skies, showers and isolated thunderstorms should persist through the overnight, with higher rainfall amounts most likely over the upslope areas tonight and into tomorrow morning. High temperatures will remain slightly below normal while low temps will remain well above normal. On Tuesday, the NAM and GFS both show about 1500 J/kg across the I-85 corridor by late aftn, as some breaks in the low overcast is expected, allowing some insolation. This will be combined with 0-6 km shear of 20-30 kts and SRH of around 200 m2/s2. The CAMs do show some discrete cells that may track NE within bands of enhanced emanating from TC or (post-TC) Alberto as it tracks into central TN. The SPC Day 2 Outlook has a marginal risk for severe weather across the entire area, with isolated brief/weak tornadoes being the biggest threat. Highs will be near normal east and below normal west under the continued moist tropical air mass. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... As of 110 PM Monday: A very moist and complicated pattern continues thru the short term. The remnants of TC Alberto will continue pulling north as it/s picked up by a developing mid/lat trof. Meanwhile...a general weakness in the sub/trop ridge will persist over the SE CONUS which will maintain moist GOM/Atl flow trained on the FA. Deep layered moisture will remain elevated with PWATs persisting abv 1.5 inches. Soundings show continued low-end conditional instability each afternoon within little general short-lived tstms are possible just about anywhere each afternoon. Otherwise...very little forcing will be the better precip/rate enhancement will be associated with mech lift where another 1-2 inches of rainfall is possible thru early Thu. This amt of rain could lead to continued and/or additional flooding concerns across the srn and ern BR...thus the FFA will be extended in time thru 12z Thu across the mtn zones. Max temps will remain arnd normal Wed and a little abv normal Thu. Mins will persist abt 10 degrees abv normal each morning. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 155 PM Monday...A broad ulvl trof will remain across the east coast to begin the period. Small scale pockets of h5 energy will traverse the FA...however overall ulvl forcing will remain weak until a more defined trof dives south out of the glakes region on Sun. The good news is moisture transport vectors within the llvls will begin to veer w/ly early Fri which will decrease the chances for precip over the non/mtns and limit any new hydro threats. The area will remain in a highly moist environ Fri however...which will make for a muggy day as high temps reach a cat or so abv normal. There is some uncertainty with the degree of airmass mixing associated with a frontal system Sat which looks to stall out across or just south of the FA thru the weekend. The GFS is drier and wetter with the pattern Sat than the ECMWF...however both models do show a diurnal precip trend which would mean isol to sct convec each afternoon. A few storms could become quite strong or severe with hail and gusty winds being the biggest threat mainly across the NC mtns...while the non/mtns will be a little more stable with lowering td/s in downsloping w/ly H9-H8 flow. The aforementioned ulvl trof will reach the area Sun afternoon or evening and this could instigate more widespread showers and tstms late Sun into Mon. Max temps over the weekend will remain abv normal by a cat or so...while mins remain well abv normal by abt 10 degrees. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... At KCLT and elsewhere: Instability has increased across the Upstate, but convection remains shallow, with little lightning. Will opt for prevailing shra and vcts at the three Upstate sites. For KCLT and other NC sites, mainly going with SHRA this evening thru the overnight. Guidance in good agreement on continued rain bands pivoting northward thru the area, producing low cigs and occasional low vis in downpours. Winds are generally ENE, but will gradually veer to ESE, then SE overnight thru Tuesday morning. Wind speeds are generally 5-12 kt. Another lull in shower coverage is expected in the morning, then daytime heating should produce another round of numerous showers and tstms in the aftn. Cig will improve gradually from IFR to MVFR with some VFR breaks by mid-aftn. Outlook: Tropical moisture will linger through at least thru Wednesday. So expect continued rounds of numerous to widespread showers and embedded thunderstorms with low cigs and occasional low vis across the region. Slightly drier air is expected to start working into the area on Thursday, but diurnal convection is still expected. Confidence Table... 02-08Z 08-14Z 14-20Z 20-00Z KCLT High 90% High 80% Med 66% High 82% KGSP Med 68% Low 55% Med 60% High 90% KAVL High 86% High 92% High 89% High 100% KHKY High 92% Med 77% High 88% Med 72% KGMU Med 66% Low 51% Low 58% High 94% KAND Med 76% Med 60% Med 63% High 94% The percentage reflects the number of guidance members agreeing with the scheduled TAF issuance flight rule category. Complete hourly experimental aviation forecast consistency tables and ensemble forecasts are available at the following link: && .HYDROLOGY... Heavy rainfall over the past two weeks across much of the forecast area, particularly the mountains, has set the stage for serious flooding and landslide issues to possibly develop with any additional tropical rainfall through mid-week. Numerical model profiles exhibiting precipitable water values over two inches and deep warm cloud layers in excess of 12 kft will make for highly efficient heavy rainfall processes and further increase the threat of flash flooding and river flooding. The latest 3/6 hour FFG guidance values are generally running 2.5 to 3.5 inches and these will be quite achievable in the expected waves of heavy tropical rain showers...especially across the higher terrain. Hydro problems will likely continue through Tuesday and possibly into late Wednesday as heavy tropical rainfall continues in waves. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...Flash Flood Watch through Thursday morning for GAZ010. Flash Flood Watch through Wednesday morning for GAZ017-018-026- 028-029. NC...Flash Flood Watch through Thursday morning for NCZ033-048>053- 058-059-062>065-501>510. Flash Flood Watch through Wednesday morning for NCZ035>037-056- 057-068>072-082. SC...Flash Flood Watch through Thursday morning for SCZ001>003. Flash Flood Watch through Wednesday morning for SCZ004>014-019. && $$ SYNOPSIS...SBK NEAR TERM...ARK/JPT SHORT TERM...SBK LONG TERM...SBK AVIATION...ARK HYDROLOGY...
Area Forecast Discussion
National Weather Service Jackson MS
1013 PM CDT Mon May 28 2018 .UPDATE... Updated for evening discussion. && .DISCUSSION... Convective precipitation associated with the outskirts of "Alberto" has diminished with loss of heating and have reduced rain chances for the overnight. The latest HRRR guidance is bearish with any additional shower activity, but will maintain some continuity with previous forecast and also to match up with neighboring WFOs. The remainder of the forecast elements are generally on track for the near term and no significant adjustments were necessary. /CW/EC/ Prior discussion below: Tonight and Tomorrow: The threat of any impacts from Alberto in our region remain low. Rainfalls totals should`t eclipse 1.0" for most locations with higher chances of precipitation. Lows tonight should fall to near 70 degrees areawide with highs on tomorrow ranging from the low 90`s along and west of the MS River to the mid 80s in eastern MS where cloud cover from Alberto will obstruct the sun. /jpm3/ Tuesday night through Sunday: Come Tuesday night Alberto is expected to be moving north from the Tennessee Valley toward the Great Lakes region. In its wake, mid to upper level troughing will linger over our CWA through Wednesday morning but this trough axis will shift east through the day as mid level ridging begins building into our region from the southwest. A moist airmass with a PWAT in excess of 1.7in will also remain over our region Wednesday and support mainly diurnal convection but greatest coverage will continue in the east with the least coverage in the west. This will result in warmest afternoon temperatures in the west as well. This warmer and drier trend look to continue into Saturday As the mid level ridge strengthens over the region. However, there remains differences in the models with the strength of the ridge and a couple disturbances that are expected to top it. The first disturbance is expected Thursday but model consensus suggest associated rain chances will remain to our north. With little convection expected in our CWA most sites look to top out in the lower 90s. Normal highs run 85-88F. Another disturbance looks to drop around the mid level ridge Friday and model consensus suggests associated convection may infringe on our eastern most zones. Yet another disturbance is expected Saturday again with rain chances being carried in our east. This will allow for a warming trend with dry weather for at least the western two thirds of our CWA Thursday through Saturday. With temperatures topping out in the mid 90s combined with high humidity, heat index values look to top out around 105F Friday and Saturday afternoons. Wl continue this mention in the HWO. Although there remain differences in the models for Sunday, consensus is that upper level troughing and a cold front will drop over our region leading to greater rain chances and cooler temperatures. /22/ && .AVIATION... 00Z TAF discussion: Aviation hazards will be largely influenced by Subtropical Storm Alberto. Look for gusty NE/N wind and showers to diminish early this evening with increasing shower chances late tonight in the GTR to perhaps MEI area when the center passes at it`s closest point to eastern MS. There will be an increase in mostly MVFR ceilings along/east of the I-55 corridor early Tuesday morning persisting until around noon before mixing upward to VFR category. GTR looks to experience the worst of impacts associated with STS Albert Tuesday with RA/VCTS likely going into the afternoon. At other sites, VCSH/VCTS could be a concern late morning and afternoon. /EC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 69 87 71 92 / 15 31 21 30 Meridian 69 86 70 89 / 30 52 38 43 Vicksburg 69 89 71 93 / 7 19 7 19 Hattiesburg 69 89 71 91 / 22 26 34 48 Natchez 69 89 72 91 / 7 19 6 17 Greenville 70 87 72 93 / 7 29 16 25 Greenwood 69 85 70 92 / 14 46 27 33 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$
Area Forecast Discussion
National Weather Service Mount Holly NJ
827 PM EDT Mon May 28 2018 .SYNOPSIS... Weak high pressure will remain across the area tonight through Tuesday night. The high will move away Wednesday as low pressure, the remnants of Alberto, move across the Ohio Valley. A warm front associated with this will approach from the south. Rather unsettled conditions will remain for the end of the week and into the weekend as low pressure aloft affects the region. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Low clouds are redeveloping across the area as the sun sets this evening. In addition, the flow is expected to become more westerly overnight, albeit light. Given the lack of continued onshore flow, considerable low clouds (due to the inversion mentioned previously), and fog parameters no more robust compared to last night, confidence in widespread dense fog is low. Therefore, kept patchy fog in the forecast, which may be locally dense. With the loss of daytime heating, absence of a pronounced surface boundary, and generally weak large scale descent aloft, kept the forecast dry for tonight. Hourly temperatures were adjusted based on a blend of short term guidance (weighted toward the RAP), and the previous forest for continuity. This resulted in little, if any change, to the low temperature forecast, with values several degrees above seasonal norms, due to the cloud cover. Previous Discussion... Showers have developed in portions of Delmarva early this afternoon, on the northern fringe of larger-scale lift associated with a quasi- zonal, elongated vorticity lobe positioned from the Ohio Valley to the central Mid-Atlantic coast. Hi-res simulations have not accounted for this development well (generally too far to the south with coverage being too sparse), so included some slight-chance PoPs the rest of the afternoon generally from Kent County (MD and DE) southward. With a surface ridge in place to the north of a deformation axis located in far southern portions of the Mid-Atlantic this afternoon, the low-level inversion has held strong across the area today, with a cloud deck stubborn to erode across the area this afternoon. Light surface flow and a subtle onshore component near the coast have contributed to the mostly overcast day. Models suggest there may be a small time window in which some breaks in the clouds occur before sunset, but the general model bias has been too optimistic today. Therefore, the confidence on such occurrence and its duration is quite low. The forecast tonight is a challenge owing to the potential implications of the current low-cloud deck on the development of fog across the area. Should the clouds remain in place, the development of more widespread fog would be less likely, even with slowly increasing dew points and light surface winds. Nevertheless, the pattern is certainly favorable for at least patchy fog, especially in rural/valley locations and near the coast, where a subtle onshore fetch will remain and the cooler ocean waters will contribute to rapid saturation after dark. With these conditions in mind, basically have mention of patchy fog everywhere after 03Z (areas of fog along the coast and offshore). Regarding PoPs, confidence is lacking given the proximity of lift to the southern CWA and at least some indications from the HRRR that showers may attempt to lift northeastward into far southern New Jersey early this evening. For now, though, have kept PoPs unmentionable for the tonight period pending improved hi-res model agreement. Temperatures will not drop much tonight owing to the increased cloud cover/fog and slowly increasing dew points. Generally have lows in the 60s across the CWA, with strong weighting given to consensus raw- model output given its somewhat better performance recently with similar conditions. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... Very challenging forecast tomorrow, with subtle surface (and upper- level) meteorological phenomena in play and little agreement among raw-model and statistical output. The large-scale pattern will feature midlevel ridging becoming a little bit stronger across the Northeast in advance of the remnants of Alberto to the southwest. Midlevel perturbations will continue to progress eastward in proximity to a deformation axis across the southern Mid-Atlantic. Warm-sector precipitation will develop to the south of the deformation axis, which will likely remain south of the CWA through the day. However, like today, we may see some development creep into the far southern portions of the area (generally central/southern Delmarva), so kept some mention of PoPs here. Meanwhile, a surface high will progress into New England and adjacent areas during the afternoon, with an apparent (albeit very weak) surface trough in place across the Appalachians. Terrain effects in combination with differential heating and subtle mesoscale convergence associated with the surface trough will likely be sufficient to initiate some convection during the afternoon to our north and west. Cannot rule out a storm or two developing in our CWA during peak heating, especially northwest of the Fall Line. Most locations will be dry tomorrow, but the environment in place (plus the subtle nature of potential initiating mechanisms) precludes me from eliminating PoPs entirely. With the southern CWA in closer proximity to the deformation axis and associated large-scale lift, expect cloud cover to be denser and longer-lived in these areas tomorrow. Meanwhile, the northern/western CWA may break out into some sun sooner. Thus, temperatures may actually be warmer to the north and west and cooler to the south during the afternoon. However, confidence on max temps is low. A comparison of MOS guidance for KPHL is instructive: 12Z MAV is 89, 12Z MET is 79, and 12Z ECS is 86. The erosion of the cloud cover will be critical to the accuracy of the forecast. I did not stray too far from consensus, as the subtly stronger ridging may counteract the models` tendencies to erode cloud cover too quickly. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... High pressure will be dropping across the Northeast states and the Canadian Maritime provinces Tuesday night and Wednesday. This will mostly keep fair weather across the region along with seasonable temperatures. There could be some patchy fog Wednesday morning in rural areas. Lows Tuesday night will be in the low 60s up north and mid/upper 60 elsewhere. Highs on Wednesday will mostly be in the 70s with a few 80s near Metro Philadelphia. Unsettled conditions will prevail through much of the long range as the remnants of Alberto move well to the west of the area and a decent batch of moisture is drawn northward with it. Several upper lows will affect the area into the weekend which will help trigger almost daily chcs for showers and tstms. Right now Thursday and Saturday look to be the the days with the higher chcs for showers and tstms with high chc and low likely pops in the grids. The other days have mostly low chc pops. Wet ground across the area could lead to some hydro concerns later this week if organized convection develops. Low confid in this happening attm. Temperatures for most of the long term will average normal or below with frequent clouds and sct showers predominating. One exception will be Friday when partly sunny skies may allow for highs to reach the mid 80s in most areas. Conditions will be rather humid through the period, especially the weekend with dew points in the 60s to low 70s. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... Tonight...CIGs should deteriorate to IFR 02Z-06Z, with the potential for LIFR at some sites after 06Z. There is also the potential for fog, though confidence in fog development/location/timing is fairly low. Winds should be light/variable. Overall confidence is low. Tuesday...Improvement to MVFR during the morning and VFR by afternoon is expected, though confidence with timing is low. Winds remain southerly or southwesterly around or below 10 kts. There is a slight chance of storms during the afternoon (especially north/west of PHL), but coverage looks sparse should these no inclusion in TAFs at this point. Overall confidence is low. Outlook... Tuesday night and Wednesday...Mostly VFR. Fog psbl early Wed. Wed night thru Saturday...Mostly VFR. Patchy rural fog psbl during the pre-dawn and sct showers/tstms during the afternoon or early evening hours. && .MARINE... Sub-advisory winds/seas are expected through Tuesday. Conditions may become favorable for fog tonight, but dense fog is not expected at this time, as the dew points - Sea Surface Temperatures differential based on buoy observations is not favorable. The pattern should be more conducive to dense fog Tuesday Night. Outlook... Sub-SCA conditions expected. Scattered showers and tstms Wed night thru Saturday with locally higher winds and seas. Rip Currents... Through this evening...The risk for the development of dangerous rip currents is moderate for the NJ beaches and low for the DE beaches. Tuesday...A moderate risk for the development of dangerous rip currents is forecast for the NJ beaches due to a combination of an increasingly onshore component of wind throughout the day up to around 15 mph, multiple swell groups of similar magnitudes (several sets from the south-southeast to the east-northeast with 7-9 second periods) which should lead to shorter periods of higher waves, and a full moon (larger variations in tides, accentuating water through sandbars). For the DE beaches, a low risk for the development of dangerous rip currents is forecast, due to the wind being both parallel to the coast and weaker. Remember, a low risk of rip currents does not mean no risk! Life threatening rip currents often still occur near jetties, reefs, and piers. The vast majority of rip current victims swam at unguarded beaches. ALWAYS SWIM IN THE PRESENCE OF A LIFEGUARD. && .EQUIPMENT... The Sandy Hook NOS tide gauge (SDHN4) remains out of service. CORMS is addressing the problem. There is currently no estimated time for a return to service. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ Synopsis...O`Hara Near Term...Klein/LF Short Term...Klein/LF Long Term...O`Hara Aviation...Klein/LF/O`Hara Marine...Klein/LF/O`Hara Equipment...
Area Forecast Discussion...UPDATED
National Weather Service Portland OR
905 PM PDT Mon May 28 2018 Updated Short term and Aviation sections .SYNOPSIS...A series upper level troughs will maintain onshore winds, and a cooler marine influence tonight through Thursday with night and morning clouds and a mix of sun and clouds in the afternoons. Brief ridging will provide a warmer day on Friday before another upper level trough arrives for next weekend. && .SHORT TERM...Today through Thursday...Evening Update: Am finding it very difficult this evening to identify what`s left of the cold front and precisely where it might be located. There is not much conclusive evidence on satellite or surface obs. Decided to pare down cloud cover for tonight and tomorrow given the lack of continuity in the cloud field over the waters. For sky cover tonight and early tomorrow, have leaned fairly heavily on a combination of the HRRR and Canadian regional model as they are showing the closest representation of reality at this time. Even so, expect inland cloud cover will be highly variable tonight with little confidence for any given location. Updated text and grids have been sent. /JBonk Previous discussion follows: A weak cold front will fall a part as it moves across extreme SW Washington and NW Oregon this afternoon and evening. This front will most likely just impact the sky cover where there will be variable cloudiness across the region. Areas south of Salem will be less impacted or not impacted at all by this weak front. The marine layer will deepen tonight as an upper level trough approaches. This combined with light onshore flow will allow any marine clouds that develop along the coast tonight to move through the coastal valleys into the Willamette Valley and parts of the Cascade foothills early Tuesday morning. There will be partial clearing Tuesday afternoon, but the afternoon temperatures should cap just below 70 degrees inland and the low 60s for the coast. There will be little change in the weather Tuesday night and Wednesday as a short wave trough reinforces the broader upper trough over the area. There may be enough lift to squeeze out brief light rain or drizzle along the north coast and the Willapa Hills late Tuesday night into Wednesday, but do not expect much if any rain accumulation. Another upper trough arrives Wednesday night and Thursday maintaining nocturnal coastal clouds, and inland afternoon clearing with Temperatures peaking in the 60s. There will be slightly more available moisture with this trough, and there is a slight chance for showers along the coast and coastal mountains Thursday morning, and over the Cascades Thursday afternoon. ~TJ .LONG TERM...Thursday night through Monday... A shortwave through finally pushes up and over the Cascades Thur night. Fri a shortwave ridge makes a brief stop, only to be pushed out Fri night, as the next system looks to approach the area, which looks to linger in the area though the weekend. The GFS and Euro disagree on if precipitation will happen within this time frame. The best chance for precipitation according to the GFS is from Sat evening through Mon as the trough makes its way into the area. However, The Euro currently has little precipitation, as it is pushing the system much further north towards Seattle within the same time frame. As a result I am keeping PoPs above Climatology,as we have a slight dry bias for the area. Especially, as the models continue to change and develop as to how this next system approaches. /42 && AVIATION...VFR conditions across most of the region this evening, with some low marine stratus developing along the central Oregon coast. With an upper trough moving into the region, expect localized low VFR to higher MVFR ceilings to settle into more widespread MVFR conditions late overnight/early Tuesday. Gusty north winds will continue both at the coast and through the Willamette Valley into the evening, briefly easing overnight/early Tuesday, but again increasing during the afternoon hours on Tuesday. Expect cloud deck to gradually lift and begin to scatter late Tuesday afternoon inland, but clouds may remain banked up along the Cascades and foothills much the day. KPDX AND APPROACHES...VFR this evening under mostly clear skies, but likely will see low VFR to MVFR cigs develop late tonight after 12z and lingering through early Tuesday morning. Expect cigs to lift slowly with daytime heating and scatter around 22z Tuesday. North to northwest surface winds ease overnight but will again be gusty Tuesday afternoon to 15 kt. Cullen && .MARINE...No Changes Made. A ridge of high pressure offshore will continue through much of the week with lower pressure inland over the Pacific NW and over Northern California. This will create a tendency for winds to be from the N or NW. Winds are expected to reach Small Craft Advisory thresholds in the afternoons and evenings through Tuesday evening, then be below Small Craft Advisory thresholds until possibly the weekend. Seas were around 7 ft this afternoon, and will be in the 7-9 foot range tonight through Tuesday from the increasing north winds. Seas will then ease back down to 6-7 ft during the mid week period as a broad upper trough sags in across the area. Seas will become choppy during the peak winds in the afternoons and evenings. pt && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory for winds until 10 PM PDT Tuesday for Coastal Waters from Cape Shoalwater WA to Cascade Head OR out 60 NM. Small Craft Advisory for winds until 2 AM PDT Wednesday for Coastal Waters from Cascade Head OR to Florence OR out 60 NM. Small Craft Advisory for Rough Columbia River Bar from 3 AM to 8 AM PDT Tuesday. && $$ 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
National Weather Service Pueblo CO
909 PM MDT Mon May 28 2018 .UPDATE... Issued at 909 PM MDT Mon May 28 2018 Updated forecast to expire Red Flag warning. && .SHORT TERM...(This evening through Tuesday) Issued at 225 PM MDT Mon May 28 2018 An upper level low will continue lifting northeastward tonight acrs northwest CO and into eastern WY. For the rest of the afternoon, thunderstorms are developing along and near the eastern mtns, and generally moving north to northeast. Will have tstms in the forecast the rest of the afternoon along the ern mtns and I-25 corridor, with best chances for severe storms over portions of Pueblo and El Paso counties and maybe Crowley. Then for this evening, the HRRR has very little chance for precip acrs southeast and south central CO after 00Z, except over northern Teller and eastern Kiowa counties. The NAM, GFS and RAP are similar to the HRRR, showing tstm chances mainly over part of El Paso and Teller counties (mainly northern portions), and maybe parts of Kiowa county. Will also keep some POPs in the forecast for some of the Continental Divide this evening, and for areas mainly north of highway 50 and then along the KS border. Later tonight the forecast models show a lines of storms working south into Kiowa county, then moving east in the mid to late morning hours on Tue. Tue the upper low is forecast to start tracking more north than east, into northwest SD and southwest ND, leaving much of southern CO dry for the day. The exception to this is the isolated precip showing up in the models over some northern portions of southern CO, including Teller and El Paso counties in the afternoon, and maybe Kiowa. .LONG TERM...(Tuesday night through Monday) Issued at 225 PM MDT Mon May 28 2018 Models continue to be in general agreement through the extended period with slightly higher forecast confidence. Main concerns will be thunderstorm potential through Wednesday, and fire weather concerns on Friday. Tuesday night through upper level disturbance is forecast to lift northeast into the Northern Plains by Tuesday evening. Models indicating isolated shower and thunderstorm activity over the Central Mountains through the evening hours before dissipating overnight. Models progs are also indicating the potential for an isolated thunderstorm across the far Eastern Plains during the evening hours. Any thunderstorms that do develop out east will quickly move east into Western Kansas during the evening, with dry conditions expected overnight. On Wednesday, expect a quick moving disturbance out of New Mexico to lift north across the area as upper level shortwave ridging moves across the area. Increased southwest flow and modest instability will lead to shower and thunderstorm development by mid day over the mountains. As the upper disturbance lifts across the region, expect continued shower and thunderstorm development from the Palmer Divide, southeast across the Eastern Plains during the afternoon and evening hours. The potential exists for a few of these storms to become strong, and perhaps severe with large hail and damaging winds being the primary threats. This activity will shift east across the Plains through the overnight hours, clearing to the east late Wednesday night. Thursday through Saturday...expect drier conditions across the region for the end of the workweek into the weekend. Southwest to westerly flow will increase, especially on Friday. This will lead to increased fire weather concerns across the region for Friday with strong gusty winds and low humidity values due to a quick moving upper level disturbance. This will need to be monitored. By Saturday, expect weaker flow across the region with less fire weather concerns. Temperatures will also be warm with many locations across the Plains pushing 100 degrees. Sunday and Monday...better chances for showers and thunderstorms will once again be possible heading into early next week. Increased moisture across the Plains and energy across the region will allow for the thunderstorms to develop. Temperatures will also be slightly cooler across the region. Mozley && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 225 PM MDT Mon May 28 2018 Gusty south to southwest winds are expected through early this evening at KALS, otherwise VFR conditions are expected, with lighter winds on Tue. Gusty eastern winds are expected this afternoon at KCOS and KPUB, then becoming westerly this evening. Forecast models show the potential for tstms at KPUB and KCOS beginning around 22Z and continuing thru about 00Z. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HODANISH SHORT TERM...28 LONG TERM...MOZLEY AVIATION...28