Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/01/17


Area Forecast Discussion
National Weather Service Denver/Boulder CO
802 PM MDT Wed May 31 2017 .UPDATE... Issued at 759 PM MDT Wed May 31 2017 Sct storms continue over the far nern plains but should gradually end by midnight. HRRR shows a few storms possibly developing behind outflow bndry moving into the urban corridor so will leave in low pops to account for this. && .SHORT TERM...(This evening through Thursday) Issued at 220 PM MDT Wed May 31 2017 Scattered showers and thunderstorms mainly firing over mountains and higher terrain and gradually moving slowly east and southeast. Storms over western sections will remain generally weak with limited moisture and weak shear. Storms will be stronger over Palmer Divide and over the far plains with a bit deeper moisture and stronger shear profile. Still a marginal chance for an isolated severe storm through the evening. Latest HRRR has strongest storm moving into the plains from Wyoming/Nebraska this evening, especially along and east of a line from Akron to Sterling. For Thursday, the ridge axis will move slowly into Eastern Colorado with a weak flow aloft. Moisture will increase over the mountains with approaching trof and a better chance for mountain storms and possibly drifting towards the adjacent plains by late afternoon/evening hours. Don`t see much of a trigger over the plains so mainly dry. Temperatures will be similar to today`s readings/ .LONG TERM...(Thursday night through Wednesday) Issued at 220 PM MDT Wed May 31 2017 Showers and thunderstorms over the high terrain and adjacent plains will slowly decrease, with the far northeastern plains remaining dry. As the upper trough moves into western Colorado overnight, a few showers may continue over the mountains and possibly over the plains due to weak QG lift and moisture associated with the trough. The upper trough will pass over in the morning with drier subsidence air behind it. Northerly winds will keep a chance of convection over the Palmer Divide and up over the southern higher terrain as some upslope flow is expected. There will also be a chance over the far eastern plains along the front. Saturday and Sunday will have only isolated convective activity mainly over the mountains as an upper ridge builds over the area. A stronger upper system will move into the Great Basin Monday then push across the Northern Rockies through Wednesday. This will pull Gulf of Mexico moisture up into the area to bring a higher chance of showers and storms over the forecast area and cooler temperatures as well. Shear, moisture and instability will likely be increasing which would result in a chance for stronger storms these three days. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 759 PM MDT Wed May 31 2017 Outflow bndry moving into DIA so will see a brief wind shift to the northeast. Winds should gradually shift back to the s/se by 05z. HRRR wants to dvlp a few storms behind the bndry however confidence in this is rather low. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...RPK SHORT TERM...Entrekin LONG TERM...Kriederman AVIATION...RPK
Area Forecast Discussion
National Weather Service Taunton MA
1047 PM EDT Wed May 31 2017 .SYNOPSIS... Seasonably warm weather arrives Thursday, then unsettled weather with showers at times returns Friday. High pressure provides dry and near seasonable weather Sat but the trend toward wet cool weather is likely Sunday into early next week as areas of low pressure affect the area. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Intensity of convection has diminished quite a bit now that we are past sunset. Low level lapse rates were very poor this evening, but mid level lapse rates were still about 6-7 C/km. This should be sufficient to maintain showers, and perhaps an isolated thunderstorm. Not thinking the strong winds and large hail from earlier this evening will be a widespread threat overnight. Tweaked rainfall chances for the rest of tonight based on latest radar trends. Local HRRR ensemble looks to have the best handle on ongoing showers, so used it as a basis going forward. Temperatures should not change much, but did tweak some to reflect latest observations. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... Thursday... Fairly robust mid level trof moves into New Eng Thu with cold front reaching the coastal plain toward evening. Westerly flow and partial sunshine will push temps well into the 70s and combined with 500 mb temps around -19C will result in CAPES 500-1000 J/kg. However, good mid level drying moves in during the afternoon and dewpoints will be dropping as well. A few showers are possible, mainly eastern half New Eng but the dry air will probably limit t-storm potential with mainly low topped showers. Soundings show a deep mixed boundary layer with potential for W/SW gusts to 20-25 mph. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... Highlights... * Mild days and cool nights Thursday night thru Saturday * Light showers possible Fri afternoon then dry Saturday * Coastal Low brings a chilly rain late Sun into early next week Synoptic Overview... Emerging omega block pattern over Canada reloads the trough over the Great Lakes and Northeast this period yielding an active pattern along with temperatures at or cooler than normal at times. Daily details... Thursday night... Short wave moving thru the area in the evening, exiting eastward and offshore overnight. However quite a dry airmass in place with westerly low level winds and precipitable water well under an inch. Some clouds expected, but overall mainly clear skies Thu night. Temps fall into the upper 40s and lower 50s. Friday... Another short waves rotates thru the base of the closed low centered over southern Quebec. Moisture continues to be quite limited with precipitable water values well under an inch, but low level lapse rates are steep. Anticipate at least diurnal clouds, will go with a low chance to slight chance for showers- any QPF would be light. Due to that limited moisture Friday is expected to be predominantly dry. Cool airmass in place over the region, so highs will be limited to the upper 60s and low 70s. Saturday... A potent short wave tracks thru our region early in the day, potentially accompanied with a weak surface trough. But once again there is very limited moisture, model soundings support diurnal clouds but showers may be very tough to come by. Surface high pressure begins to build eastward for the afternoon. This will likely be the better day of the weekend. Highs near to somewhat below climo in the upper 60s and low 70s. Sunday... Sunday brings a substantial increase in moisture and this is where our precip chances notably increase. Yet another short wave rounds the base of the upper trough on Sunday, with a surface low intensifying and advancing eastward thru the Great Lakes Region. Then there is potential development of a secondary low near the Mid Atlantic coastline during Sunday night. There is some model discrepancy regarding timing of onset of precip- 00Z ECWMF was quicker, with precip coming in Sunday morning, but 12Z ECMWF and GFS are slower and hold precip off until the afternoon. Will go with high chance pops. With cloud cover, and rainfall, it will be cooler than normal with highs only in the 60s. Monday and Tuesday... Digging short waves serve to push the extent of the upper trough further to the south. For our area these short waves, along with the potential for one or two areas of surface low pressure, will bring a continued chance for rain. East to northeast winds are expected to keep temps noticeably cooler than normal. Wednesday... Models differ here, but showing the potential for the trough to push far enough south where it is centered near or southwest of our area. Will go with a chance for showers. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Thursday/...Moderate confidence. Tonight...Any lingering evening convection is expected to dissipate overnight. Areas of IFR in stratus and fog expected to last across PVD/Cape/Islands, with IFR developing towards 04Z BOS/ORH. VFR conditions may persist in the CT valley tonight. Thursday...IFR stratus and patchy fog may linger along the south coast into the morning. Otherwise, mainly VFR conditions with sct-bkn cigs 5-6 k ft. Low risk of a few showers east of the CT valley. W/SW gusts to 20 kt. KBOS TAF...Moderate confidence in TAF. KBDL TAF...Moderate confidence in TAF. Outlook /Thursday Night through Monday/...Moderate confidence. Thursday night...Mainly VFR conditions. Gusty westerly winds around 25 kt across the interior. Friday and Saturday...A period of MVFR-IFR conditions possible in scattered showers, but timing uncertain. Greatest risk for lower cigs/vsbys late Fri into early Sat. Sunday and Monday...MVFR-IFR conditions possible in low clouds and showers especially afternoon and night. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Thursday/...High confidence. Winds and seas expected to remain below Small Craft Advisory thresholds through Thursday. W/SW gusts to 20 kt developing across nearshore waters during Thursday. The greatest concern for mariners will be areas of dense fog and poor visibilities tonight into early Thu over south coastal waters. Outlook /Thursday Night through Monday/...Moderate confidence. Thursday night... Seas and west winds expected to remain below SCA thresholds. Dry. Friday and Saturday... Modest WNW winds thru this period. Seas also below SCA thresholds. Chance of showers Friday, then dry Sat. Sunday and Monday... Increasing east winds late Sun and Sun night, possibly reaching low end Gales (35 kt) Sun night into Mon. Rain possibly heavy at times along with fog will limit vsby. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...KJC/NMB NEAR TERM...Belk/KJC/NMB SHORT TERM...KJC LONG TERM...NMB AVIATION...KJC/NMB MARINE...KJC/NMB
Area Forecast Discussion
National Weather Service State College PA
1147 PM EDT Wed May 31 2017 .SYNOPSIS... An upper low will track across southern Ontario and Quebec over the next couple of days. Another cut off upper low will likely form over the Great Lakes this weekend and drop southeast toward Pennsylvania early next week. && .NEAR TERM /UNTIL 8 AM THURSDAY MORNING/... Convection just about done. We will leave isold POPs along the MD border just in case that cell/cluster decides to continue on. HRRR and RAP do think it will continue for a bit. Skies will be generally clearing. Have added fog for some of the area as this clearing should allow temps should get down to the dewpoints in many locations. Some wind would bust this fog forecast, but many locations are already calm. Prev... Nice outflow from storms over PIT earlier this evening just came through with 30-40 gusts at many locations. However, the rain from it fell apart and only smaller cells are left as it moves into the Lower Susq. What will be neat to watch is the potential interaction of that outflow with one coming up from MD - crossing the M_D line right now. Where these outflow boundaries collide is a place where more showers/storms form due to the added/cumulative lift provided by both fronts. Also, the CAPES are still above 500 Joules per the latest RAP estimates from SPC plots. Have sct POPs in the SE third of the area for the next few hours. Elsewhere, the sct convection should be waning and moving off to the east. Effective shear is still high at 35-45kts, but without realizing the CAPE becoming kinetic/real, there isn`t much of a worry for severe. Still bears an eye on the radar - especially if you are at an outside event this evening (graduations?). Prev... Moderate CAPES of 1000+ J/kg moving east of my CWA this afternoon, with steep lapse rates and general pockets of 350 to 850 J/kg CAPES to work with across the remainder of the Central and North Central Mountains this afternoon. Disorganized open cellular convection traversing areas mainly north of I80 at mid afternoon, with a few reports of pea sized hail resulting from these...despite tops no higher than 20k feet and storm cores remaining below 10k feet. Additional activity has sprouted along the lake breeze and will be scattered about the Northwest Mountains through late afternoon. HRRR tracks a broken line of showers into the central mountains by 02z before dissipating convection by mid evening. Gusty showers with brief heavy downpours and isolated pea sized hail and wind gusts of 30+ mph will be the main sensible weather from convection through early evening. Convection will die rapidly towards sunset as large scale forcing tracks east of the commonwealth. Partly cloudy skies will prevail overnight with mins ranging from the mid to upper 40s north to the mid 50s southeast. && .SHORT TERM /8 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... Thursday will be the best day of the bunch coming up with most areas enjoying mostly sunny conditions and low humidity. It will be a cool for the first day of June...but we`ll take it as long as we remain dry. Mixing down GEFS mean 850mb temps of 6-9C only translates to max temps of the mid 60s across the higher terrain of the Alleghenies, to the mid 70s over the Lower Susq Valley. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... The long range models continue to play kick the can with precipitation this weekend. The models do have relatively good agreement among med range guidance, all of which track upper low from southern Quebec to the Canadian maritimes Fri-Sat. A potent shortwave rounding the base of the upper low is progged to come through Pa late Friday, accompanied by scattered showers/storms. Behind this feature, surface ridging and a push of low PWAT air now accompanied by scattered showers/storms. Behind this feature, surface ridging and a push of low PWAT air now appears likely to result in a dry Saturday. The models begin to diverge on a solution Sunday into early next week. However both bring a return of unsettled/showery weather. The models continue to disagree on the timing and form of the low pressure system. The GFS has an upper low forming a more open which should become a deepening trough as it moves through the Great Lakes. This would stall precipitation and gives a slower solution. The EC forms a closed low that moves through about 6 to 12 hours faster. The ensembles have diverging solutions among its members so consistency is lacking. As such, have a broad timeframe of higher POPS with the highest POPs to Sunday into Monday. This is when bulk of model data track a low level jet and associated plume of higher PWATs across Pa. All long range guidance does show a return to cooler/showery wx through the first half of next week. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... Lingering showers to the east of all airfields but KLNS where a few light showers remain. A few areas of fog are possible overnight but generally VFR conds are expected on breezy winds over the east and high pressure building into the west. .OUTLOOK... Thu...VFR/No sig wx. Fri...VFR with chance of PM showers/Tstorms. Sat...VFR/No sig wx. Sun-Mon...Sub-VFR likely with showers and thunderstorms. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo NEAR TERM...Dangelo/DeVoir SHORT TERM...DeVoir/Fitzgerald LONG TERM...Fitzgerald/Ceru AVIATION...DeVoir/Gartner
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
938 PM CDT Wed May 31 2017 .UPDATE... Overall, forecast is in good shape but made some minor adjustments to the PoP grids to account for current radar activity. Most activity is on a weakening trend with the bulk of the showers and storms east of the I-35 corridor and will show the highest PoPs in this region. Updated products have been sent. && .PREV DISCUSSION... /ISSUED 715 PM CDT Wed May 31 2017/ UPDATE... See below for the 00z aviation update... AVIATION... The complex of showers and thunderstorms moving over SAT presently should continue to move northward out of the area by 1z. However, showers and thunderstorms are expected to linger in the vicinity the Interstate 35 sites for the remainder of the evening and through Thursday afternoon, so have VCSH and VCTS in the TAFs accordingly. Any shower or thunderstorm that does manage to impact the TAF sites will lower visibilities/ceilings, and could pose a gusty wind threat and even perhaps some small hail. Otherwise, all TAF sites should remain VFR through the evening hours before lowering to MVFR overnight and then improving once more to VFR by late Thursday morning/early Thursday afternoon. CIGs at a few sites, namely SAT/SSF, could perhaps lower to IFR for a brief time overnight, but did not have high enough confidence to include that in the TAF at this time. Winds will generally be out of the southeast at around 5 knots. PREV DISCUSSION... /ISSUED 245 PM CDT Wed May 31 2017/ SHORT TERM (Tonight through Thursday Night)... A mid level shortwave was seen on water vapor satellite imagery mid afternoon crossing out of Mexico and into the southwest CWA. Mesoanalysis reveals the atmosphere has de-stabilized ahead of the shortwave across southern and eastern zones, where SBCAPE values around 2000-2500 J/KG reside. Scattered showers and thunderstorms are developing this afternoon southwest of San Antonio and development to the east and northeast is expected through the remainder of the afternoon and evening as the shortwave tracks northeast through the unstable airmass. TT WRF and HRRR indicate the disturbance and showers and storms exiting northeast of the area around midnight. A second disturbance upstream overnight and into early Thursday morning should mainly stay north of the CWA. High pops on Thursday will be confined to eastern areas during peak heating, where a pool of moisture and general weakness will remain. A few storms coming of the higher terrain of Mexico may make a run toward the Val Verde county Thursday evening, but confidence is low in the storms holding together before reaching the CWA. Can`t rule out a few stronger storms this afternoon and early evening and again Thursday afternoon, producing small hail, strong downburst winds, and very localized pockets of 1-3 inches of rainfall. LONG TERM (Friday through Wednesday)... Models have been indicating a slight downtrend in POPs Friday and Saturday, with higher POPs mainly confined across the Coastal Plains, near a deeper moisture pool, as well as western Edwards Plataea and Rio Grande, closer to weak disturbances in the southwest flow. A trough is forecast to deep late Saturday through Sunday from North Texas southwest into the Big Bend, and eventually slide southeast through the area Sunday into Monday. POPs do look to increase during this time. A few pockets of locally heavy rainfall will also be possible. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 69 88 70 88 71 / 60 40 20 10 10 Austin Bergstrom Intl Airport 69 87 69 88 69 / 60 40 20 20 10 New Braunfels Muni Airport 69 86 70 88 70 / 60 50 20 20 10 Burnet Muni Airport 67 85 68 86 68 / 60 40 20 10 20 Del Rio Intl Airport 70 87 72 88 72 / 30 20 20 20 20 Georgetown Muni Airport 68 86 69 87 69 / 60 40 20 10 10 Hondo Muni Airport 68 87 70 88 70 / 50 40 20 10 10 San Marcos Muni Airport 69 87 70 88 70 / 60 40 20 20 10 La Grange - Fayette Regional 71 87 71 88 71 / 50 50 20 30 10 San Antonio Intl Airport 68 86 71 88 71 / 60 50 20 10 10 Stinson Muni Airport 69 86 71 88 71 / 60 40 20 20 10 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Mesoscale/Aviation...Williams Synoptic/Grids...Hampshire Public Service/Data Collection...YB
Area Forecast Discussion
National Weather Service Memphis TN
1011 PM CDT Wed May 31 2017 .DISCUSSION... A couple of clusters of storms over northern sections of the Mid- South this evening. Latest GOES-R IR imagery suggests an old outflow boundary from near the MO border in NE AR into NW TN. Expect these storms to weaken over the next couple of hours and dissipate. Will extend pops for a couple more hours. HRRR hinting at some patchy fog and low clouds over NE MS but should be less widespread than last night. Tweaked temps a bit otherwise forecast looks good. SJM && PREV DISCUSSION... /issued 352 PM CDT Wed May 31 2017/ Scattered thunderstorms will continue across northeast AR this afternoon and are forecast to move across the Mississippi River into west TN this evening. There is a modest amount of surface based instability with MLCAPE values near to just above 1000 J/kg. Vertical shear is somewhat on the weak side, however, with effective-layer bulk shear ~30 kts. These parameters suggest a mix of ordinary and multicell thunderstorms this afternoon. Storms are expected to remain sub-severe, with the primary hazards being small hail and gusty winds. Storms will wane after 03z with generally dry weather anticipated overnight. The upper-level trough centered over New England will remain quasi-stationary through the weekend. West to northwest winds aloft will persist during this time, allowing weak shortwave troughs to move across the Ohio Valley. Concurrently, a weakening trough will lift northeast across the Southern Plains Thursday, but this wave will damp out as it approaches the shortwave ridge axis extending from the Mid-South, northwest into the Central Plains. PoPs were trimmed to 20-30% across most of the CWA on Thursday given the relatively weak forcing, but scattered diurnal activity is still expected. Similar conditions are anticipated on Friday with rain chances being the greatest during the afternoon hours. Given the diurnal nature of this convection, we anticipate relatively low coverage during the overnight hours. Thus, only slight chance PoPs were included Thursday night and Saturday. Rain chances peak over the weekend as a stronger trough dives southeast across the Ohio Valley, phasing with the slow moving trough over the Plains. The pattern may support a few strong to severe storms, but organized severe weather doesn`t appear likely at this time. Expect rain chances to taper off Monday night as the trough axis crosses the Mid-South. Temperatures through the weekend will remain seasonal with highs generally in the low to mid 80s and overnight lows in the 60s. Dry weather is anticipated Tuesday and Wednesday with dry northwest flow aloft on the backside of the departing trough. Temperatures will be a bit cooler in the wake of a cold front with highs near 80 degrees and overnight temperatures falling to around 60 degrees. Johnson && .AVIATION... 00Z TAF cycle VFR conditions should persist for most of the forecast period. A few isolated thunderstorms are possible this evening but coverage will be too limited to mention in TAFs. Some patchy areas of fog are possible overnight which may produce some periods of MVFR visibilities. Winds will be mainly light and variable for much of the forecast period. ARS && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1006 PM EDT Wed May 31 2017 .SYNOPSIS... A weak front will remain north of the region tonight then drift offshore and dissipate Thursday. Offshore high pressure will dominate this weekend. A stronger cold front will approach from the west early next week and move offshore Tuesday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 1005 PM Wednesday...After some strong to severe storms earlier in the day, the CWA is currently dry. However, additional showers and tstms have developed east of a boundary across central NC and look to approach our Coastal Plains counties shortly. The latest HRRR and RAP models indicate this activity traversing our CWA through the early morning hours and have a 30 pct PoP area-wide as the atmosphere has greatly stabilized from the previous convection. Lows tonight remain mild or roughly near 70 by the coast and upper 60s inland. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... As of 300 PM Wednesday...A trof across west central NC now, separating humid conditions over the eastern part of the state (dewpoints near 70) from drier air farther west (dewpoints in the 50s) will move through our area while washing out. Overall it looks like a dry day but a few isolated storms are again possible, right along the sea breeze. Overall though convection should be even more limited than today. With a better chance for more sunshine, highs will be a tad warmer or generally in the middle to upper 80s. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... As of 315 pm Wed...Mainly dry through Friday, then precip chances increase Saturday through early next week. Temps continue above normal through the period. Weak surface front will move off the coast Thursday night with a drier and more stable airmass in its wake, which will be in place across the region on Friday with a light west wind. Both GFS and ECMWF show a shortwave passing through during the day but with a dry airmass in place will keep the forecast dry. On Saturday, afternoon surface trof develops across the coastal plain and in tandem with inland propagating sea breeze, a few diurnal showers/storms possible. Sun-Tue...This period will bring a better chance of organized precip as global model suite indicating a deepening trough across the Great Lakes region. This feature will drive a strong cold front towards the Southeast CONUS. Moisture return will increase out of the SSW and with falling heights from east to west, better shower/tstm chances arrive. Still too far out in time to advertise anything higher than 40-50 percent as ensemble spaghetti plots exhibiting too much spread in height fields. Temps should be just a touch cooler during the day with increased cloud cover and precip coverage, though nights will remain very warm with increasing humidity levels. Highs in the low/mid 80s and lows in the 70s through Tue, then cooling Wed with highs in the mid/upper 70s and lows in the lower 60s coastal plain to mid/upper 60s south coast and Outer Banks. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Short Term /Through 00Z Friday/... As of 715 PM Wednesday...Generally a VFR forecast for this TAF cycle as thunderstorms have moved south and east of the TAF sites and any additional activity will be widely scattered overnight. Light mixing and leftover cloud cover should preclude most of the fog overnight. VFR conditions are expected for Thursday as weak ridging will dry out the airmass a bit. Long Term /Thu through Sunday/... As of 315 pm Mon...Mainly VFR through Friday. Better chance for sub-VFR Saturday through Mon with chances for scattered convection increasing each day. Surface winds will be WSW around 5 kt Fri and Sat, and SSW 10-15 kt Sunday. && .MARINE... Short Term /Tonight and Thursday/... As of 1005 PM Wednesday...Still picking up wind gusts to around 20 knots over the waters between Oregon Inlet and Ocracoke, while all other coastal waters and Sounds should see SW winds 10-15 knots overnight. Seas are 3-4 feet with a few 5-footers over the central legs. With a weak boundary to the north slipping south on Thursday, winds will gradually become W/WNW in the afternoon and diminish to around 10 knots as weak high pressure builds in behind the boundary. Long Term /Thursday through Sunday/... As of 315 pm Mon...South to southwest winds forecast through the period. A weak front will pass through Thursday night, with a stronger front approaching from the northwest early next week. Winds will average 5-15 knots through Saturday night, with seas on the coastal waters 2-3 feet. As the pressure gradient increases Sunday into Monday, speeds will increase to mainly 15-20 knots on the coastal waters, with seas building to 3-5 feet north of Oregon Inlet, and 4-6 feet south. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...None. && $$ SYNOPSIS...EH NEAR TERM...CTC SHORT TERM...EH LONG TERM...HSA AVIATION...CTC/EH/HSA MARINE...CTC/EH/HSA
Area Forecast Discussion
National Weather Service Omaha/Valley NE
634 PM CDT Wed May 31 2017 .SHORT TERM...(Tonight through Saturday) Issued at 328 PM CDT Wed May 31 2017 Forecast concerns in the short term will be shower and thunderstorm chances tonight through Thursday evening and again Friday night through Saturday along with potential for severe storms. The 12Z OAX sounding was fairly dry with around a third of an inch pwat while TOP had 0.86. The 12Z upper air charts had an upper level jet over the Ohio River Valley and Mid-Atlantic states...with some upper level divergence near the MO Valley in the right entrance region of the jet. Northwest flow at h5 with a couple of weak shortwaves were noted over SD/Neb. H7 moisture was pooled in a northwest to southeast from central Nebraska into Kansas. The latest satellite imagery reflects this moisture along with h7 warm air advection with a band of clouds. WSR-88D reflectivity shows elevated showers and ENTL has a couple of clusters of thunderstorms over central Nebraska moving into southeast Nebraska. The active severe weather has been over parts of KS and MO where MLCAPE has been around 1500-2000j/kg in combination with the mid level shortwave and surface boundary/60s dewpoints. Surface high pressure over the area will lose it`s grip over the area and gradually the energy in the northwest flow will work east as h85 low level theta-e advection increases...pulling h85 northward. h85 dewpoints are forecast to increase to 10 to 15 degrees in a northwest to southeast band overnight and during the morning along with warmer h85 temperatures from 15 to 18 deg. The h85 low level jet increases to 30 to 40kts in southeast Nebraska by Thursday morning...then veers...trending the storms more eastward. As is typically...the various models have varying solutions as to the northward extent of the measurable precipitation along with varying amounts. The trend of the RAP/HRRR/ESRL HRRR is to slowly bring the showers and isolated thunderstorms eastward into southeast Nebraska during the evening...then increase the coverage in the 7-12Z time period in southeast Nebraska/parts of east central Nebraska. Have the highest likely pops in this area...however with the pooled moisture and the warm front lifting north...did carry chc/slight chc farther north. Warm air advection continues during the and forecast soundings show that convection would become surface based. CAPE values increase to 3000-4000 j/kg...however 0-6km shear is around 30 kts...there is a risk for severe storms. Highs Thursday-Saturday should be in the 80s. The cold front moves into the area Friday night with another round of storms. .LONG TERM...(Saturday night through Wednesday) Issued at 328 PM CDT Wed May 31 2017 A storm system will move over the great lakes and this may bring a few showers/thunderstorms for parts of the forecast area depending on where the surface boundary is located. Highs Sunday should be in the 70s and 80s...but cool to the 70s early next week. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 604 PM CDT Wed May 31 2017 VFR conditions expected thru the fcst pd at both KOFK/KOMA. Concern at KLNK is possible VCTS late tonight/early Thurs morning. Expect TSRA activity to push into nern KS shortly after 06z tonight before reaching into sern Neb. At this point...most likely time frame for KLNK to see any TSRA activity would be between 09z-12z Thursday morning. VFR thereafter at KLNK. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Zapotocny LONG TERM...Zapotocny AVIATION...DEE
Area Forecast Discussion
National Weather Service Norman OK
1052 PM CDT Wed May 31 2017 .AVIATION... Surface winds behind an outflow boundary in north central are generally east and southeast late this evening. Farther south in north Texas, a small cluster of storms is moving northward and an isolated shower/storm may move close to SPS through 6Z. Otherwise, high clouds will remain over the area tonight. Scattered showers and storms should form across Oklahoma and north Texas Thursday from 17z-23z, then gradually weaken during the early to mid evening. Stronger storms with heavy rain tomorrow afternoon should lower visibility below 3 miles with wind gusts over 35 kts. && .PREV DISCUSSION... /issued 947 PM CDT Wed May 31 2017/ DISCUSSION... HRRR temperatures were loaded for the night into the grids as the model has done quite well with the outflow in northern Oklahoma and the forecasted showers and storms glancing part of northern Texas west of I-35. Pops were added to these Texas areas for scatted showers and thunderstorms into the night. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 65 85 66 82 / 10 30 30 50 Hobart OK 65 85 66 83 / 20 40 50 60 Wichita Falls TX 67 85 68 84 / 30 50 50 50 Gage OK 60 85 63 82 / 20 20 30 50 Ponca City OK 62 87 66 84 / 20 10 10 50 Durant OK 68 85 68 84 / 10 30 50 50 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$
Area Forecast Discussion
National Weather Service Mount Holly NJ
950 PM EDT Wed May 31 2017 .SYNOPSIS... Low pressure across Canada will cause a cold front to cross the area late tonight. A weak area of high pressure will be across the area late Thursday. Another cold front will affect the area Friday before more high pressure builds in for Saturday. A prolonged period of unsettled conditions is expected beginning Sunday and continuing well into next week as a frontal system and low pressure develop over the northeast United States. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 937 PM: final update for this shift. Many reports of .25 to 1" hail on the NJ storm. Also had hail in Monroe earlier this evening. LSR summary is out and thats only the 1/2" and larger. For the rest of the night...used COSPA and kept it as showers except thunder nw of I95. seems to be too stable for thunder much longer. Patchy fog late. From earlier: Warning Hail was on CIMMS 90% and VIL 40-45+. Many reports hail enroute. MRMS hail size and track exct for Hunterdon and Somerset. Remainder below from 4 PM. Tricky forecast this evening, as the kinematic and thermodynamic environment are increasingly supportive of strong to severe convection, but weak/nebulous foci for small-scale lift provide considerable uncertainty regarding coverage and overall severity. Convection-allowing models are highly variable in projections of convection late this afternoon and evening, with some HRRR simulations generating little convection anywhere in the CWA and others producing rather widespread coverage during the evening hours along a weak and weakening pre-frontal surface trough. The individual members of the NCAR ensemble are more aggressive in generating scattered strong to potentially severe storms across the area, particularly north of the Mason-Dixon Line (in closer proximity to large-scale ascent with a glancing vort max in the upper-level flow). However, the latest WRF-ARW and WRF-NMM provide support for the sparser-looking NAM Nest. Given the weak large-scale dynamics in play, I have a hard time buying the more aggressive/widespread convective coverage this evening, despite relatively little inhibition currently in place. Nevertheless, should any storms develop, MLCAPE 500-1000 J/kg and effective bulk shear 35-45 kts are supportive of organized storms. Notably, the strongest shear reaches the area later this evening when surface-based instability will diminish with the loss of daytime heating, which may reduce the severe threat with any storms that develop to some degree. Combined with timing discrepancies among the guidance, forecast confidence in precipitation coverage/intensity this evening is very low. Thus, kept PoPs confined to slight generally south of I-78/I- 195 and low-chance north of there. Generally, chances for precipitation decrease late this evening and should pretty much be confined to the Atlantic after midnight or so. Other main question with tonight`s forecast is chances for patchy fog. There is at least some indication of near-saturation at the surface late tonight before a cold front moves through the area. Patchy fog is possible, though should be far less widespread and less dense than observed last night. Latest MOS is not very supportive of fog outside of coastal New Jersey, so generally kept out of the forecast for now. Lows generally in the lower 50s in the Poconos to the lowers 60s in the urban corridor and Delmarva. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... A vort max will swing through the Northeast late tonight, bringing drier air into the region tomorrow. This should foster a rather splendid day across the area, with mostly sunny skies and seasonal to slightly above seasonal temperatures. Main forecast issue tomorrow is wind, with deep mixing likely as westerly surface flow becomes established. Fortunately, 850-mb flow looks rather weak (around 20-25 kts), so gusts 15-25 mph may be all that the region can muster. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... The upper air flow across the Northeast part of the country will still resemble more of a spring-like pattern this weekend and early next week, even though we are now in meteorological summer. An upper trough will be across the Northeast Friday before lifting away Saturday and Sunday. It will be followed by weak ridging Monday, before giving way to another upper low and trough Tuesday and Wednesday of next week. Temperatures through the period will not be favorable to any excessive heat. Temperatures, instead, may run a little below normal especially into the new week, when frequent clouds and showers are expected. Normal high temperatures for early June range from the low 70s north and near 80 over Delmarva and metro Philadelphia. The operational models are not in wonderful agreement with regards to the day-to-day weather across the area. We will focus on the more general aspects of the fcst. Fri...Mostly dry, but a front will bring some afternoon showers to the area. Sat...probably the best day of the extended period. We will have a dry forecast at this point. Sunday...The beginning of the day will be dry, but then showers will arrive along with the next system from the Great Lakes. Thunderstorms are possible. Monday-Wednesday...A rather cloudy and unsettled period with frequent showers and below normal temperatures. We will keep pops for Wed at slight chc attm. Confid in details are very low going into next week. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Tonight...VFR. Sct-bkn aoa 7000 ft. chance of a shower or tstm but at this time no mention til we are more certain. South to southwest wind. Patchy fog late tonight, especially at KACY and KMIV, with local sub- VFR VSBYs possible in the 06Z- 12Z period. Thursday...VFR sct clouds aoa 5000 ft briefly bkn in the aftn. west to southwest wind gusts to near 20 kt in the afternoon. OUTLOOK... Thu night...Mostly VFR. Fri/Fri night...Mostly VFR, but scattered afternoon showers/tstms with lower conds psbl. Sat...VFR expected. Sat night thru Monday...Lower conds possible with frequent showers. && .MARINE... 9 PM: Swell and seas raised by a foot and added 2 seconds to the period through Thursday. We may eventually have to issue an SCA for parts of our coasts Thursday but not at this time. Sub-advisory winds/seas expected through Thursday. Patchy fog is possible through the night. Mention in the forecast grids through the overnight hours, though no advisory appears warranted at the moment. A slight chance of showers exists overnight. For now no thunder expected. Tomorrow looks to be a fine day on the water with west or southwest winds 10 to 15 kts and seas generally around or below 3 feet. RIP CURRENTS... Rip Risk Thursday: Moderate! Because there is a longer and higher swell than modeled, coming in from the east and tracking this through 44066,65,09. Once it settles down out there then we eventually have less concern along our coasts. So, despite an offshore wind Thursday...the risk for dangerous rip currents is more substantial than recent days. Be smart and careful and swim within sight of lifeguards. OUTLOOK... Generally sub-SCA conditions thru the period. Sct Showers/tstms Fri night and Sun-Mon. SCA conditions on the ocean psbl later Mon. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ Synopsis...O`Hara Near Term...CMS/Drag 950 Short Term...CMS Long Term...O`Hara Aviation...CMS/Drag/O`Hara 950 Marine...CMS/Drag/O`Hara 950
Area Forecast Discussion
National Weather Service Reno NV
232 PM PDT Wed May 31 2017 .SYNOPSIS... Cooler temperatures and a few showers remain through tonight. We will see a warming trend with decreasing winds Thursday through Saturday. Another cool down with stronger winds is possible late in the weekend and into early next week as the next low pressure system reaches the western U.S. && .SHORT TERM... Low pressure continues to move across northern Nevada and California today, with abundant cloud cover and light rain showers. Showers will taper off this evening, with clearing late tonight as low pressure moves out of the area. Breezy winds will also continue into the evening hours with wind gusts up to 25-30 mph. Winds will calm down tonight as the gradients drop off. High pressure builds back over the region Thursday through Saturday with warming temperatures and drying conditions. High temperatures will increase a few degrees each day, reaching to near 10 degrees above average by Friday-Saturday. Highs will get into the upper 80s by Friday in western Nevada and 70s in the Sierra valleys. Hoon .LONG TERM...Sunday through Wednesday... By Sunday, another area of low pressure deepens off the Pacific Northwest Coast, sending a shortwave trough into northern CA/NV Sunday into Monday. This shortwave will bring increasing winds to the region, bringing a cold front through Sunday afternoon. There may be enough dynamics and moisture along the front on Sunday afternoon to kick off a few isolated thunderstorm north of Susanville-Gerlach. Elsewhere, it looks like the winds will be the biggest story. Wind gusts over 30 mph may be possible on Sunday, leading to choppy lake conditions and potential increase in fire weather conditions. See our fire weather discussion below more more details. Temperatures will cool off several degrees Monday behind the front, but then ridging will take hold again as we go into the middle part of next week with temperatures rising again to near 10 degrees above average. Hoon && .AVIATION... Scattered VFR showers swinging through the region this afternoon. Latest HRRR guidance has this precipitation completely moving out by 2Z this evening with clouds decreasing. Gusty W/NW winds from surface gradient will persist through then as well, before diminishing. Looks like a few nice days for flying Thursday into Saturday as temperatures warm. Couple minor caveats to that: * Gusty winds Thursday afternoon, W/NW G15-20 KTS. * Areas of fog and low stratus at TRK pre-dawn Thursday morning, possibly again Friday morning. Stronger winds looking likely Sunday as another cold front approaches. Not a big mountain wave event with ridgetop flow only 30 KTS but some solid turbulence likely for approaches/departures. -Chris && .FIRE WEATHER... Fuels remain for the most part non-critical precluding issuance of fire weather watches/warnings. However carryover grasses in W Nevada lower elevations are plenty dry and 2017 extensive grass crop is starting to dry in zones 450/459 per GACC and my own observations on the trails. So we still have to be mindful of any days with gusty winds and low humidity - we`ve already seen a few wildland fires near Pyramid Lake and in Lyon County. One such day to watch appears to be Sunday. Simulations have been consistent in bringing a cold front across N Nevada, with varying tracks. In most scenarios, the increasing pressure gradient with this front would result in widespread gusts above 30 MPH with minimum RH below 15% in most of W Nevada. Duration on the order of 2 to 4 hours in the afternoon-evening. Forecast confidence is medium. Any grass fires that start in pockets of already dry grasses could spread quickly. -Chris && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$ For more information from the National Weather Service visit... http://weather.gov/reno
Area Forecast Discussion
National Weather Service Blacksburg VA
922 PM EDT Wed May 31 2017 .SYNOPSIS... Weak cold front moves southeast of us by Thursday morning with high pressure keeping dry weather into most of Friday. A backdoor front enters northern Virginia Saturday, then stalls across the mid-Atlantic into Sunday before next cold front moves in Sunday night. && .NEAR TERM /THROUGH THURSDAY/... As of 910 PM EDT Wednesday... Strong convection across the south that broke through a decent cap aloft per evening soundings continues to slowly weaken and should shift east of the area in the next hour or two. However still have another band of showers working across and west of the Blue Ridge associated with residual upstream outflow, so appears some added showers may linger through midnight despite limited instability. This well in advance of the actual dewpoint front that lags back across the Ohio River. Expect this boundary to finally push across the region during the early morning hours bringing the onset of drier air by early Thursday. Latest short term guidance basically dry along the front as appears most support all but gone during the overnight hours. Thus leaving out any pop mention after midnight. Otherwise appears fog the main issue later tonight espcly where the heavier downpours have occurred across the south as slow clearing takes place. Kept temps close to previous with just a nudge up in lows given lingering moisture. Previous discussion as of 300 PM EDT Wednesday... Two narrow lines of showers and storms this afternoon ahead of a front and along outflow boundary, but mainly within a region of weaker instability and dynamics per mesoanalysis. So at the moment nothing more than garden variety showers and storms. As the storms move further east, the instability increases a little as does 0-6km bulk shear, but overall not expecting widespread severe threat. Thinking now is an isolated hail or wind damage threat mainly east of a Lynchburg to Triad NC line, and even more so further east and south. High-res solutions continue to have variability in coverage with latest HRRR showing best coverage this afternoon from the New River Valley south into the NC foothills, then weakening it further east with a few more showers erupting ahead of another sfc trough/convergence boundary over the mountains of WV around dusk. Most models seem to weaken and dry things out by late evening. As we head into the over the deeper moisture stays over the coastal areas, with weak high pressure moving into the upper Tennessee Valley and Ohio Valley by dawn Thursday. Should see some clearing late with drier air advecting somewhat to the mountains. Fog is questionable but with some shower activity and wet soils, may see some fog in the river valleys late. Lows tonight will range from the lower to mid 50s in the mountains, to upper 50s to around 60 east of the Blue Ridge. Thursday will be dry under high pressure with axis of broad 5h trough overhead. Anticipate plenty of sunshine, lower humidity but warm temps in the 70s mountains to lower to mid 80s east of the mountains. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 250 AM EDT Wednesday... The passing of a front Wednesday night will usher in cooler temperatures to start the day Thursday. However, under dry conditions with dew points in the upper 40s to mid 50s, abundant sunshine will help push afternoon temperatures 3F-5F warmer than normal. The area will remain under the influence of an upper level trough Thursday, so a few fair weather cumulus clouds are possible in the afternoon. Any afternoon clouds will fade during the evening with high pressure settling over the region overnight. Overnight lows will be close to normal and with dew points in the 50s, it may be a good night to leave the windows open. Surface high pressure will either move east or weaken through the day, being replaced with a weak lee trough in the east. With a west wind across the mountains and low instabilities, we have lowered the PoPs Friday afternoon. Models are now forecasting a warm front to track across the Ohio Valley Friday, then north over the Mid Atlantic Friday night. This new solution would keep most of Friday dry with light showers advancing north overnight. Previous forecast were showing more diurnal convection in the afternoon, fading in the evening. Again with less rain and clouds expected Friday, we bumped up temperatures a few degrees with mid to upper 70s west and mid to upper 80s east. The warm front will move north Saturday with winds out of the southwest. Both heat and humidity will increase with afternoon temperatures warming to near 80F across the mountains and upper 80s east into the piedmont. Instabilities will also increase through the day with scattered afternoon convection likely. Decaying diurnal convection`s outflow will keep convection going deep into the evening. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 230 PM EDT Wednesday... Cold front approaches early Monday which should assist in generating additional showers and thunderstorms during the day but front should advance steadily across the CWA limiting chances for heavy rainfall. A few severe storms possible under this scenario depending on timing and other mesoscale factors. The long-wave pattern early next week shows an unseasonable upper low/trough over the northeastern U.S. with ridging back over the the high plains with several lower amplitude waves riding eastward from parent upper low over the Gulf of Alaska. This pattern should result in mainly west to northwest flow across our CWA with the main frontal boundary well to our south along the Gulf and southeast coast. Would not be favorable for much severe or heavy rain although cool air aloft and daytime heating could yield some pulse storms. Temps will be cooler than seasonal norms with highs 60s to 70s and lows in 50s to possibly even a few upper 40s by mid-week. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... As of 705 PM EDT Wednesday... Line of deeper convection now crossing the KBLF vicinity should push quickly southeast toward KBCB/KROA in the next hour or two and likely weaken. However expect a period of MVFR to ocnl IFR conditions along with brief wind gusts to 30-35 kts along the leading edge of these shra/tsra through perhaps 01Z/9pm. Other stronger storms should pass south of KDAN where will only include a VCSH mention over the next few hours. Showers should also stay just south of KLWB this evening with KLYH looking to stay far enough east to avoid much convection before loss of heating. Appears most coverage should fade a couple hours after sunset with clearing after midnight if not sooner as instability fades. Cannot rule out a brief period of MVFR vsbys at KBCB/KBLF late tonight with river fog though drier airmass may restrict that. Extended Aviation Discussion... VFR conditions are expected Thursday and Friday with little to no convection. A stronger system is expected to arrive for the weekend-Monday with widespread showers, thunderstorms, and sub- VFR conditions for at least some periods of time. The other exception to VFR conditions will be any late night valley/river fog, or in areas that receive late day rain. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...WP NEAR TERM...JH/WP SHORT TERM...PC LONG TERM...PC AVIATION...JH/RAB/WP
Area Forecast Discussion
National Weather Service Tucson AZ
200 PM MST Wed May 31 2017 .SYNOPSIS...Isolated showers and thunderstorms north and east of Tucson into early this evening. Near normal temperatures will continue through Friday, then then turning warmer over the weekend into early next week. There may be enough moisture around for a slight chance of thunderstorms in the eastern mountains again early next week. && .DISCUSSION...Weak troughing aloft currently resides across California into western Arizona. While the atmosphere has dried out slightly over the past 24 hours based on latest surface dewpoint and GPS PWAT data, we are still seeing some isolated convective activity this afternoon but certainly less than this time yesterday. Latest KEMX radar shows a few showers and thunderstorms as far west as a Bisbee-Oracle-Dudleyville line with mainly just flat cumulus clouds for points westward from there. Expect isolated showers and thunderstorms to continue this afternoon into early evening, especially across the higher terrain north and east of Safford which the latest HRRR depicts fairly well. Any residual showers and thunderstorms will wind down after sunset. Thursday will still have a little bit of moisture right along the New Mexico border resulting in a slight chance of showers and thunderstorms and will also be the coolest day of the forecast period with highs a few degrees below normal. Otherwise, heading into this weekend and early next week, the main story will be the ridging building back in across the area with warmer temperatures returning. Expect highs back into the triple digits for the deserts including Tucson starting Saturday and continuing through the middle of next week. Moisture will be hanging on close by just to the east of our area and may seep into the the White Mountains from time to time especially early next week and we are depicting a slight chance of showers and thunderstorms for far northern Greenlee County to account for that. && .AVIATION...Valid thru 02/00Z SCT-BKN clouds above 20k ft AGL through the forecast period, with FEW-SCT clouds at 10k-15K ft AGL thru about 01/04Z from KTUS eastward. Isolated -TSRA/-SHRA will continue east of KTUS with the best coverage from KSAD northeast into this evening. SFC winds sly/swly SFC wind at 10-15 kts with gusts to around 20 kts thru 01/03Z, then less than 10 kts again into Thursday morning then sly/swly again around 10-15 kts Thursday afternoon. Strong, gusty and erratic outflow winds possible with any thunderstorm that does develop. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Isolated showers and thunderstorms are possible across Graham, Greenlee and Cochise counties into early this evening and then in the White Mountains Thursday. Rainfall amounts will be very light. However, expect strong, gusty and erratic outflow winds with any thunderstorms that do develop with the potential for lightning started running grass fires. Dry conditions will then prevail across most of the area Friday through Tuesday of next week, with just a slight chance of thunderstorms in the higher terrain along the New Mexico state line early next week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson