Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/01/17

Area Forecast Discussion
National Weather Service State College PA
1124 PM EDT Sun Apr 30 2017 .SYNOPSIS... A nearly stationary front will remain draped across central Pa tonight. A strong cold front will move across the region on Monday followed by brisk west to northwest winds and cooler air for Tuesday. Fair weather with milder temperatures will occur Wednesday under a weak ridge of high pressure. Deep moisture will flow north into the state Thursday afternoon through Friday bringing a return to inclement weather. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Earlier convection has completely dissipated late this evening, as boundary layer cooled/stabilized. Expect a dry remainder of the night for most of central Pa. However, can`t rule out a shower/storm working into Warren County toward dawn, as low level jet shifts eastward from the Grt Lks. Persistent easterly flow off of the Atlantic will likely yield low clouds and possible ridgetop fog across eastern Pa late tonight, while a partly cloudy night appears likely across the central mountains and Alleghenies. A blend of latest HRRR and LAMP support overnight min temps from around 50F over the high terrain of eastern Schuylkill County, to the low 60s across the south central counties and Allegheny Plateau. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... Monday represent the most active day in the forecast period. A potent cold front is expected to pass through the region during the afternoon and early evening Monday. Strong deep layer shear and respectable instability are generated by all the near term deterministic models. SPC has elevated the RISK to ENHANCED with EHI`s forecast in the 2-3 range (anything above 1.0 is considered significant). The mitigating factor to be aware of (as always) will be the amount of cloud cover in the warm air ahead of the cold front. The cool air damming as defined by low level stability is forecast to mix out rapidly early in the day. With the cold front and upper flow strongly aligned, I would expect the warm sector to mix out and at least a healthy mix of sun and clouds to develop by mid to late morning. Temps should return/rise to very very warm levels on Monday. A narrow north/south ribbon of +3-4 sigma PWAT air along and just ahead of the cold front will support some locally heavy downpours and QPF up over one inch in some spots. WPC highlights a small portion of my NERN zones with a MARGINAL risk of heavy rain/flooding. It`s too soon to get into watches at this point. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... Expect significant convection to be ongoing/near to exiting the CWA at the start of the period Monday night. Cold front forcing the convection will move east through the state overnight into Tuesday morning, advecting much chillier air into the state Cyclonic flow with a gusty NW wind and unsettled light showery weather will persisting mainly for the northern part of the state right into Wednesday. A chance for a more widespread (potentially MDT to HVY) rain arrives Thu into Fri as latest 00Z Operational GFS/EC run and their EFSs are coming into decent/converging agreement with an area of low pressure progged to develop along the southern Appalachians and the lift north-northeastward. Although this event shows some pretty strong signals (even at this long time range) for a potential, widespread 1-2 inch rainfall late in the upcoming week, A wide and varying array of models solutions has been present prior to the latest model run or two to throw some uncertainty into the mix w/respect to the specific timing and amount of showers across the CWA. Fri night and Saturday will turn windy and quite cool with isolated rain showers falling across the central mtns, while the Alleghenies experiences more numerous rain showers (and yes, maybe even the last gasp of show showers until later this fall). && .AVIATION /04Z MONDAY THROUGH FRIDAY/... Some showers and thunderstorms across western NY. At this point, left them out of BFD. 03Z TAFS adjusted for current and expected conditions. Western areas have the best chance to remain VFR overnight, as a cooler southeast flow of air remains over the far east. Main issue later Monday is a strong cold front from the midwest that will move across the region later in the day with showers and storms. Strong winds will be possible with some of the storms. Main question remains, is drier air to the east this evening going to taper the intensity of the storms on Monday. After the front moves east of the area, a dry slot will likely result in clearing later Monday night into Tuesday. As winds shift more to the northwest late Tuesday into Wednesday, this will bring more clouds and showers to the area, mainly across the west and north Tuesday Night into early Wednesday morning. A complex low pressure system will likely bring more wet and stormy conditions to the area after Wed. Outlook... Mon...Breezy. Showers/thunderstorms likely with periods of sub-VFR. A few strong-severe storms possible wrn 1/2 Monday afternoon/evening. FROPA Monday night. Tue-Wed...Breezy with a chance of showers NW. Thu-Fri...Widespread sub-VFR with rain likely. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte NEAR TERM...Fitzgerald SHORT TERM...La Corte LONG TERM...Lambert/Gartner AVIATION...Martin
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1203 AM EDT Mon May 1 2017 .AVIATION... An extension of low pressure over Illinois will move toward southern Lake Michigan during the rest of tonight. This will nudge the warm front a little farther north into southern Michigan and allow some of the VFR conditions over Ohio to spread northward. Improved conditions could reach as far north as FNT before the occluded front arrives toward sunrise. At the same time, a close watch for fog will be warranted in the weakly supported warm sector supporting a relatively light southeast to south wind. The front will then bring another round of showers and possibly some storms northward from Kentucky while the ongoing storms over Illinois stay to the west and north. Borderline IFR/MVFR ceiling will accompany the showers/storms until the front sweeps it all eastward by late morning. VFR will follow with southwest wind gradually increasing to gusts in the 30-35 knot range during the afternoon. Generous coverage of showers is also likely by mid afternoon through early evening as daytime surface heating interacts with cooler air aloft. For DTW... Monitoring prospects for VFR to move in from Ohio and also some fog potential during the remainder of tonight. A more certain downward trend back to MVFR/IFR will follow as the front moves in along with another round of showers and possible storms, timing of which will be refined with later updates. Gusty southwest wind will become the main concern by afternoon. //DTW THRESHOLD PROBABILITIES... * Moderate for ceiling 5000 ft or less through morning. * Low for thunderstorms through morning. && .PREV DISCUSSION... Issued at 917 PM EDT Sun Apr 30 2017 UPDATE... Evening satellite imagery depicts a textbook mature mid latitude cyclone affecting a broad swath of the central U.S. which will drive the precipitation trend over southern Michigan during the rest of the night. Smaller scale upper waves/MCVs and their interactions with the warm/stationary front have been the main forcing over the last 24-36 hours, and will be for the evening pattern, followed by the primary low pressure system becoming more involved overnight. The good news here is that rainfall rate has been light overall during the late afternoon and early evening, especially over the flood watch area of the Saginaw Valley and northern Thumb, and storm totals south of the watch area have averaged about 0.5 inch according to surface obs and radar estimates. Any upgrades to or expansion of the watch are therefore not anticipated at this point. Statements and graphics will be issued to cover trends with the main short term concern possibly being some urban ponding of water on roads in the Detroit area. The primary low pressure system and frontal occlusion will enter Lower Michigan late tonight and bring another round of showers and scattered thunderstorms to the region. This activity will move quickly through SE Michigan while possibly disrupting the morning peak travel period before being swept eastward into Ontario by late morning. PREV DISCUSSION... Issued at 251 PM EDT Sun Apr 30 2017 DISCUSSION... Rapid fire upper level disturbances/MCV`s embedded in moist airmass with next weaker one seen on Goes R Ice Channel 5 already lifting north through Western Ohio Valley. Blossoming area of showers on the northeast flank has limited the destabilization over northern Indiana, but still enough to maintain showers and possible thunderstorms into southeast Michigan late today/this evening. With the failure of warm front to lift into the State during daylight hours and limited instability it remains highly doubtful we will see any severe weather in our CWA. Still, 12z NAM/Regional Gem do indicate 1000-850 mb capes nearing 1000 J/kg close to Lenawee county at 00z, while RAP is displaced farther east with the pocket of instability, which looks better based off the temps in the 80s over Eastern Ohio. Much like the QPF bulls-eyes, models running a bit too hot. is always weary with such a strong low level jet (50+ knots at 850 mb), even overnight as the jet strengthens further, 65+ knots, but surface based inversion is expected to hold. Flood watch will remain in effect for Tri-Cities and adjacent counties, as we received solid rainfall today pushing totals to around 1 inch. Will get additional rain (half an inch to maybe 1 inch) late tonight with the cold front, as the large upper level low over the Central Plains is finally booted off to the northeast from the upper level energy working through the northern Rockies. Moisture axis will slide east of southeast Michigan between 12-14Z with good part of the day under influence of mid level dry slot. However, good low level cold advection and cyclonic flow will eventually spread scattered to numerous showers back into the area, right into Tuesday as 850 mb temps of -4 C settle overhead. Certainly plausible for graupel to fall with that amount of cold air. Based of forecasted nam soundings and local probabilistic wind forecast, wind gusts of 35 to 40 mph look to be common late in the day Monday, with gusts at above 30 mph continuing right into Tuesday, as 992 mb low slowly tracks through the northern Great Lakes. Highs around 50 degrees on Tuesday will likely be the best we can do. High pressure building in across the Ohio Valley will keep conditions dry throughout Wednesday as temperatures remain moderate, with daytime highs capped in the upper-50s. The next chance for rain showers will enter Thursday morning into Friday as a low pressure system pushes in from TN into PA. PoP values will continue to remain sub-30 across the Metro Detroit area for this potential system as only the GFS and to some extent the ECMWF solution bring the low north enough, allowing the precipitation shield to clip southern Michigan. Breezy conditions and a slightly better chances for rain showers look to take place throughout Friday as moist-laden conditions wrap around the low pressure system to its northwest. Lastly, an upper-level disturbance pushing in from southern Ontario into the Great Lakes throughout Saturday will bring additional chances for rain showers. High pressure is then expected to build over Michigan Sunday into Monday, bringing some relief from the rain. Otherwise, temperature trends will remain fairly consistent through the middle and end of the week, with daytime highs remaining in the upper 50s to lower 60s and lows in the 40s through Sunday. MARINE... Moderate easterly winds over northern and central lake Huron will begin to ease this evening as the gradient relaxes. A secondary increase in easterly flow remains possible across northern Lake Huron tonight and early Monday. Winds will turn to southerly and increase on Monday as low pressure lifts west of Lake Michigan. Gusts as high as 30 knots look to develop by afternoon and continue through the overnight hours. The combination of higher waves under the easterly flow through tonight, transitioning to gusty conditions on Monday will maintain an extended period of small craft advisory conditions for Saginaw Bay and portions of the nearshore waters. Winds are expected to shift to the west behind a cold front on Tuesday, with windy conditions persisting through Tuesday night. HYDROLOGY... Widespread rainfall is expected through Monday morning, with periodic heavy rain possible. There will also be a chance for thunderstorms during this time. This additional rainfall in combination with rain that has fallen already this weekend will result in total rainfall amounts up to 2 inches. The highest amounts will be focused along and north of a line from Flint to Harbor Beach. Locally higher totals are possible for areas that experience thunderstorms, as storms will bring brief periods of torrential rainfall. Rivers and streams will see significant rises through the middle of the week, and ponding of water may develop in low-lying areas and roadways. Flooding is possible, particularly over the Saginaw Valley. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...Flood Watch through Monday morning for MIZ047>049-053-054-060-061. Lake Huron...Small Craft Advisory from noon Monday to 4 AM EDT Wednesday for LHZ442-443. Small Craft Advisory until 4 AM EDT Wednesday for LHZ421-422-441. Lake St Clair...Small Craft Advisory from noon Monday to 4 AM EDT Wednesday for LCZ460. Michigan waters of Lake Erie...Small Craft Advisory from noon Monday to 4 AM EDT Wednesday for LEZ444. && $$ AVIATION.....BT UPDATE.......BT DISCUSSION...SF/AM MARINE.......MR HYDROLOGY....MR You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion
National Weather Service Wilmington OH
930 PM EDT Sun Apr 30 2017 .SYNOPSIS... Thunderstorms will occur ahead of a cold front that will move across the area late tonight into Monday morning. Much cooler air will move in behind this system with below normal temperatures expected through the rest of the week. Wet weather will return during the latter part of the week as low pressure slowly tracks across the Tennessee Valley. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... A complex of thunderstorms that moved into the area from the southwest has significantly weakened as instability has decreased. Still though, DCAPE values are around 800 J/kg so can`t rule out some gusty winds with it. Another thin band of showers and thunderstorms in association with the cold front towards the Illinois/ Missouri border will push east this evening. This band will then cross the CWA border around 06z. As the band heads east it should remain mostly weak but given the strong bulk shear can`t completely rule out gusty winds (even though the bulk shear is boundary parallel). During the day tomorrow the vertically stacked low pressure will head across Wisconsin with a tight pressure gradient across the region. 850/ 700 mb winds will be around 40 kts with low level mixing allowing 35 kts gusts. GFS forecast soundings show slightly higher values on momentum transfer while the NAM is slightly less. For now have kept wind gusts in the 30 to 35 kt range. Prev Discussion-> Scattered thunderstorms that have been tracking across far eastern counties this afternoon will move east of the area over the next several hours. Appears that MCS lifting out of the mid South will make it into western counties this evening, although in a continuing weakening phase. New convection will develop along a strong cold front and move into the forecast area late tonight, likely after 2 am. CAPE may still be around 500 J/kg as this enters our area with instability waning further towards daybreak as the line progresses east. 0-3 km shear is forecast to be mainly parallel to the line which is not particularly favorable. But cannot rule out the potential for some strong to possibly severe storms late tonight. System is rather progressive, so while there could be some locally heavy rainfall, the lack of persistent rain should minimize flood potential. But with saturated ground in much of the region, could still be some minor flood issues here or there. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... Line of showers and thunderstorms will still be ongoing at the beginning of the period but exiting the area by mid morning as a cold front moves east. Looks like there could be some clearing right behind the front. But then the combination of moisture wrapping in behind the system and insolation should result in a rather extensive stratocumulus deck. Winds will become gusty. At this point expect them to remain below wind advisory criteria. A short wave rotating around an upper low in the Great Lakes will swing across the region Monday night. This may result in a few showers, mainly to the north and west of Dayton. In the wake of this short wave clouds may start to erode from the south later in the night. Winds will decrease a bit from their speeds during the day but still persist between 10 and 20 mph. In cold advection, temperature rise on Monday will only be 5-8 degrees from morning readings. Lows Monday night will fall back into the 40s. && .LONG TERM /TUESDAY THROUGH SUNDAY/... An upper level low pressure system situated over the northern Great Lakes Tuesday morning will shift east across Quebec through Tuesday night. This will help keep our area in cool cyclonic flow through the day on Tuesday with a few showers possible across the northern fringe of our fa. With a 35-45 knot 925-850 mb jet rotating across our area through the day and some developing low level CAA, winds will be gusty once again through the day. Mid level short wave energy dropping down across the Plains will help carve out a trough over the Mississippi Valley through mid week. This will eventually lead to a closed low developing which is then forecast to drift slowly east across the Tennessee Valley through the end of the week. As an associated surface low moves slowly east across the Tennessee Valley, expect fairly widespread showers to slowly overspread the area later Wednesday and into the day on Thursday. A chance of showers will then linger through Friday and possibly into Saturday as the upper level low slowly pushes east. High pressure and a drier airmass will then try to build into the area for Sunday. With the cool upper level low affecting the region through much of the long term period, temperatures will remain several degrees below normal through most of the week. Some moderation back closer to normal will be possible by the weekend. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... All TAF sites currently VFR this evening with an area of low pressure centered over the Kansas/ Missouri border. The occluded low pressure will pull northeast with a front pushing east. Ahead of the front several rounds of showers and thunderstorms will be possible but uncertainty is high as coverage will be low. Better agreement exists with the cold front that is forecasted to push across the TAF sites between 09z and 14z. In general, the latest runs of the HRRR and RAP have slowed down the frontal passage (along with the band of showers and thunderstorms) but am having trouble believing this. Usually the front speeds up at night. For now have kept TAF forecast package showing similar timing as the previous package. As the line of showers and thunderstorms crosses the TAF sites gusty winds and IFR visibilities will be possible. Behind the front winds will slowly veer and pick up in speed. GFS and NAM forecast soundings are showing gusts up to 35 kts possible. Higher wind gusts will be possible towards DAY/ CMH/ LCK or closer to the low pressure center. OUTLOOK...Wind gusts to 35 kt possible Monday evening and then again on Tuesday. MVFR ceilings and visibilities possible Thursday through Friday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Haines NEAR TERM...Haines SHORT TERM... LONG TERM...Haines AVIATION...
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
858 PM CDT Sun Apr 30 2017 .UPDATE... Updated for evening discussion. && .DISCUSSION... Leftover moisture axis over eastern sections has allowed for convective development this evening as the cold front has closed in. Although the latest HRRR data is showing this, it is somewhat slow in its development. Regardless, convection should begin picking up some eastward progress as the front holds its course. As has already been the case, would not be surprised to see another severe leftmover or two over southeast sections in the better instability and shear, but should diminish before midnight./26/ Prior discussion below: along the Mississippi river this afternoon and is working its way across the area. The bulk of the morning/early afternoon convection has shifted off to the east of the area, but stratiform and some embedded thunderstorms are occuring east of the I-55 corridor. Some shower/thunderstorm activity is developing behind this stratiform shield, but feel these storms will remain below strong/severe limits as the area has been worked over from the morning/early afternoon storms. The cold front will move across the area this afternoon through the evening hours and this will bring in drier air along with clearing skies as we get into the overnight hours. The winds will be breezy out of the southwest after frontal passage overnight. Monday will be a nice but breezy day across the ArkLaMiss with mainly clear skies and highs in the mid/upper 70s. The winds will gusty out of the southwest tomorrow afternoon, with gusts from 25-30 mph. /15/ Monday night through Sunday: Monday evening our winds aloft will become near zonal as the closed low lifts farther to the northeast across the Great Lakes region. A weak 1015mb surface high is expected to be centered just off the southeast Louisiana coast. The surface high will drift over southeast Mississippi and aid in radiational cooling that will send temperatures into the lower 50s Tuesday morning. Normal morning lows run in the upper 50s. Zonal flow aloft will continue Tuesday as the surface high shifts slightly east. Under decent insolation, temperatures will warm into the low to mid 80s, which is a few degrees warmer than normal. The dry weather will last into Wednesday morning but our winds aloft will back to the southwest and waa will strengthen over our west in advance of a northern stream shortwave digging over the Plains. The GFS is perhaps the most aggressive with this system in closing a low off over Arkansas by Thursday morning and generating a deeper 1103mb surface low that looks to track across or northwest zones Wednesday night. Wl start off Wednesday morning with a PWAT less around three quarters of an inch but by evening ahead of the cold front, models show PWATs surging to near two inches across our southwest. The GFS and Canadian depict strongest convection across our southern zones and south Wednesday night. Considering the instability and shear, a few strong to severe storms with heavy rainfall look possible. The GFS appears to be the outlier this model run with a less progressive evolution of the system. Model consensus ends the main rain chances over our CWA late Thursday afternoon although an amplified upper level trough will remain over our region until lifting out Saturday. As a result low chances of light rain will continue over our northeast through Friday. Elsewhere, dry weather is expected Thursday evening through Sunday. Cooler than normal temperatures are expected Thursday through Saturday morning. Highs Thursday and Friday will be in the 60s at most locations. /22/ && .AVIATION... 00Z TAF discussion: Ceilings will continue to slowly rise through the evening with VFR conditions returning after 01/03Z. A few showers and possibly a thunderstorms will still be possible around KMEI and KHBG until 01/03Z. Southerly winds will become southwesterly after 01/06Z, but speeds will continue at 10 to 20 knots and gusts at 20 to 30 knots, especially after 01/15Z./26/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 52 78 53 83 / 7 0 0 3 Meridian 54 78 49 83 / 72 0 0 3 Vicksburg 51 78 52 84 / 1 0 0 3 Hattiesburg 53 81 51 85 / 87 0 0 1 Natchez 51 78 53 83 / 2 0 0 1 Greenville 51 76 54 81 / 1 0 0 4 Greenwood 52 75 51 81 / 4 0 0 4 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$
Area Forecast Discussion
National Weather Service Jacksonville FL
944 PM EDT Sun Apr 30 2017 .UPDATE... Breezy/Windy S/SE flow ahead of approaching cold front will be main story tonight with the ATLC coast remaining at 15-20G30 mph through the night while inland areas should fade closer to 10-15G25 mph. It took a while this evening but Sea Breeze mergers finally took place along the I-75 corridor across inland NE FL with a few showers/isolated storms tracking off towards the N/NE while a few showers possible near the merger across inland SE GA as well. These will last through the late evening hours but generally expected to fade by midnight. Models still showing the low level moisture in the moderate southerly flow should be enough to develop a Broken/Mostly CLoudy stratus deck around 2000 feet off the ground after midnight which may become overcast in some locations by morning. This cloud cover along with the sustained southerly flow will keep overnight temps very mild with lows around 70 degrees in most places and in the lower/middle 70s near the coast and other inland bodies of water. Not much change for Monday as slow progression of pre-frontal trof/cold front towards the East across the SE U.S. will result in Breezy/Windy South FLow and much above normal temps well into the mid/upper 80s all areas with some near 90 degree readings along the I-95 corridor and St Johns River Basin of NE FL. Mainly dry conds in the morning with a slight chance of a few pre-frontal showers across inland SE GA and the Suwannee River Valley. Otherwise expect increase in shower/storm activity by the afternoon hours with scattered/numerous coverage close to the boundary across inland areas while late day scattered coverage possible along the I-95 corridor and St. Johns River Basin as models trying to push a slowly moving inland Atlc Coast Sea Breeze that will help to initialize more possible activity. Main threat from the storms will be possible marginal/damaging wind gusts in both of these areas but also some large hail across some of the inland SE GA storms. && .AVIATION... Gusty S/SE winds will continue through the night and despite 30-35 LLVL jet just off the surface likely not enough to support LLWS in TAF package. Otherwise SREF and HRRR both supporting decent chances of MVFR CIGS developing in the 1500-2500 range overnight at all TAF sites and have trended in this direction with a slight decrease in winds by 08z time frame. MVFR CIGS continue through the morning hours while southerly winds increase, then heating should allow for at least SCT/BKN CIGS in the VFR range around 3500-4000 ft by 16-17z time frame so have trended this way and have added VCSH to account for possible isolated shower activity, but too far out to account for any possible Storm activity yet. && .MARINE... Stiff S/SE winds at 15-20 knots continue to build surf at local buoys and latest 18z NWPS run had 5-7 ft seas in the offshore waters later this evening so have tweaked the timing and started the offshore Small Craft Advisory this evening and left the SCEC headlines for the nearshore waters for now with 4-6 ft seas nearshore. South flow will continue to increase ahead the cold front on Monday with 20-25 knots and higher gusts expected and Small Craft Advisory all NE FL/SE GA waters expected. Rip Currents: Moderate Risk in the moderate S/SE flow along the coast. Sunday Breaker reports at the beaches were generally had surf in the 2-3` occasional 4` range. && .FIRE WEATHER... Smoke from West Mims wildfire will continue to push NW/N overnight tonight then shift N/NE towards coastal SE GA on Monday ahead of approaching cold front. Decent mixing from south winds at 10-15 mph tonight will keep much of the smoke off the surface upwind from the fire so not likely going to re-issue Special Weather Statement (SPS) for smoke issues. && .CLIMATE... April 2017 marks the 14th consecutive month with above normal temperatures at JAX airport. Last below normal month was February 2016. && .PRELIMINARY POINT TEMPS/POPS... AMG 69 88 59 85 / 20 50 40 10 SSI 74 82 67 80 / 10 50 40 20 JAX 71 90 67 84 / 10 40 50 20 SGJ 72 88 69 80 / 0 40 50 40 GNV 69 89 67 85 / 30 30 50 30 OCF 69 90 69 85 / 30 30 50 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...Small Craft Advisory until 4 AM EDT Tuesday for Waters from Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM- Waters from Fernandina Beach to St. Augustine FL from 20 to 60 NM-Waters from St. Augustine to Flagler Beach FL from 20 to 60 NM. Small Craft Advisory from noon Monday to 4 AM EDT Tuesday for Coastal waters from Altamaha Sound to Fernandina Beach FL out 20 NM-Coastal waters from Fernandina Beach to St. Augustine FL out 20 NM-Coastal waters from St. Augustine to Flagler Beach FL out 20 NM. && $$ Hess/Cordero/Walker
Area Forecast Discussion
National Weather Service Nashville TN
836 PM CDT Sun Apr 30 2017 .DISCUSSION... New showers and thunderstorms pushing up from northeast Mississippi and northwestern Alabama, ahead of approaching cold front, means our temporary lull in precip over western areas is about to come to a close. A few storms could still be strong overnight, but potential is decidedly less than what we saw earlier today. In addition, will probably cancel our Wind Advisory before 9 pm and issue a new one for tomorrow. && .AVIATION... 00Z TAF DISCUSSION. BNA/CKV/CSV...Line of storms is about to exit Middle Tennessee, with only a few showers occurring elsewhere across the mid state. The cold front is still west of MEM, and the HRRR does show a second line of convection moving into Middle Tennessee from the southwest later this evening, so look for another round of SHRA/TSRA in a few hours. Surface winds will remain quite strong well into the evening, and have included a LLWS remark at CSV for the strong LLJ. Look for VFR wx tomorrow, although surface winds will remain brisk. && .PRELIMINARY POINT TEMPS/POPS... Nashville 58 70 51 77 54 / 90 10 0 0 20 Clarksville 54 65 49 75 52 / 70 10 10 10 20 Crossville 56 67 47 70 50 / 100 40 0 10 10 Columbia 56 69 50 77 54 / 70 10 0 10 20 Lawrenceburg 57 70 49 77 54 / 90 10 0 10 10 Waverly 54 66 50 76 54 / 70 0 0 10 30 && .OHX WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 10 PM CDT this evening FOR Bedford-Cannon- Cheatham-Clay-Coffee-Davidson-De Kalb-Dickson-Giles-Hickman- Houston-Humphreys-Jackson-Lawrence-Lewis-Macon-Marshall-Maury- Montgomery-Perry-Robertson-Rutherford-Smith-Stewart-Sumner- Trousdale-Wayne-Williamson-Wilson. && $$ DISCUSSION......19 AVIATION........08
Area Forecast Discussion
National Weather Service Raleigh NC
845 PM EDT Sun Apr 30 2017 .SYNOPSIS... Bermuda high pressure will extend across the SE states through tonight. A cold front will approach the Appalachians late tonight, then cross the region late Monday afternoon through Monday evening. Cooler high pressure will build in from the southwest Tuesday through Wednesday. && .NEAR TERM /THROUGH TONIGHT/... As of 845 PM Sunday... The latest radar and satellite data indicate the widely scattered showers lifted into the western and northern parts of NC. The convective parameters also show the MLCapes were dropping off rapidly with nightfall. The latest HRRR and other Hi-Res models suggest that the chance of showers has essentially ended in all but the western Piedmont. This is the region where some low level convergence and a SE flow will continue to support widely scattered showers late evening into the overnight (gradually shifting back into the Blue Ridge as the night progresses). Late tonight, the approaching trough to our west is forecast to move slowly NE. The pressure gradient is forecast to gradually tighten overnight. A developing low level jet will aid in increasing surface winds to between 10 and 15 mph. This will also maintain a warm moist boundary layer (BL), which when combined with the aforementioned winds, should result in a low overcast of stratus later tonight. Lows should hold into the upper 60s and lower 70s. && .SHORT TERM /Monday and Monday night/... As of 300 PM Sunday... The closed mid level trough over the Midwest Monday morning will move NE across the Great Lakes during this period. It`s assoc cold front will cross our region late in the day Monday and at night. A pre-frontal band of showers and thunderstorms is expected to move across central NC Monday afternoon and evening. Isolated severe thunderstorms will be possible as this band moves across, thanks to a moist unstable airmass over our area (characterized by ML cape 600- 1000 J/kg) coupled with 40+ kt of 0-6km bulk shear. It`s worth noting that several CAMs indicate an earlier band of showers and tstms moving up from GA and SC and across our western zones during the morning hours. That early activity, and assoc cloud cover, could impact the evolution of later storms, so we`ll have to watch that closely. In any event, have brought pops in early (during the morning hours) across our western zones to account for the potential for this earlier activity, then likely pops across all of central NC during the afternoon and evening. Right now, it appears that the bulk of showers and storms should be east of highway 1 by 03Z, and exit the coastal plain counties of central NC by 06Z-08Z. Otherwise, with a tight pres gradient in place ahead of the front, look for breezy s-sw winds ahead of the front during the day Monday with non-thunderstorm gusts up to 25-30 mph. Highs will range from around 80 across the Triad to mid 80s across the Coastal Plain, and will be largely dependent on early-day rain chance and resulting clouds. Cooler Monday night behind the front - lows from the mid 50s Triad to low 60s Coastal Plain. && .LONG TERM /Tuesday through Sunday/... As of 305 PM Saturday... More changes in the last 24 hours for the long term forecast as models are getting a better handle on a progressive longwave trough that will move across the CONUS this week and cause some problems by the end of the work week. Yesterday at this time models showed the trough moving slowly across the deep south and producing a cutoff low which was going to keep the threat for showers and storms around though the weekend. It also showed two surface low pressure systems developing that would have lingered across the Carolinas for days. Now models are hinting at one surface low pressure system that is more progressive and spurred on by the developing upper low that never slows down across the deep south. This will cause the primary window for showers and storms to be Thursday night through Friday night with a cold front crossing central North Carolina. The front moves through by the weekend and aside from a few shortwaves moving around the upper low behind the front, the weekend should be drier and cooler. Aside from this system later in the period, expect mainly dry conditions with high temperatures in the upper 70s to lower 80s prior to frontal passage on Friday when temperatures will dip back into the mid 60s to lower 70s for Friday and Saturday before rebounding back into the low 70s everywhere for Sunday. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... As of 720 PM Sunday... 24-HR TAF Period: Southerly flow will strengthen tonight as the MSLP gradient tightens from the west, in advance of an approaching cold front. Expect MVFR/IFR ceilings to develop after midnight in assoc/w low-level warm advection. Ceilings are expected to gradually improve to MVFR/VFR by noon as mixing deepens and southerly flow further strengthens to 15G25KT by mid afternoon (20G30KT by late afternoon at eastern terminals). A line of showers and thunderstorms along/ahead of the approaching cold front is expected to cross central NC from west to east late Monday aft/eve, near the end of the 00Z TAF period. Surface wind gusts as high as 40-50KT will be possible in association with the aforementioned line of convection. Looking Ahead: VFR conditions will return in the wake of the cold frontal passage late Mon night and persist through mid-day Thu. Widespread adverse aviation conditions are expected in assoc/w a potent storm system progged to affect the Carolinas late Thu through mid-day Friday. -Vincent && .Climate... Daily Record High Minimum Temperatures May 1 / Greensboro... 65 (2012) Raleigh.......67 (2012) && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett/np SHORT LONG TERM...Ellis AVIATION...Vincent CLIMATE...Badgett
Area Forecast Discussion
National Weather Service Blacksburg VA
1135 PM EDT Sun Apr 30 2017 .SYNOPSIS... A cold front moves through the eastern United States Monday. Weak high pressure follows the front with drier weather for Tuesday and Wednesday. && .NEAR TERM /THROUGH MONDAY/... As of 1123 PM EDT Saturday... Made minor changes to the forecast to account for location of showers over the NW NC foothills/piedmont. HRRR and RAP showing most shower activity through early morning to stay across the Blue Ridge south of Floyd into the NC mountains/foothills. Upped winds a little as well but think advisory levels should not be realized, except perhaps at the higher peaks of far SW VA. Special WX statement issued earlier to account for gusts up to 45 mph thanks to 50-55 kt low level jet moving in after 05z. Previous discussion from early evening... Satellite/radar showing limited coverage for showers, much less thunder in our forecast area early this evening. Small area of low level convergence situated over southside VA helping with a few showers there. Otherwise will wait until midnight or so to see better lift/enhancement across the southern Blue Ridge for more shower development. Previous discussion from mid afternoon... Deep upper closed low over western Oklahoma this morning will track northeast to southeast Iowa by Monday morning then to northeast Wisconsin by Monday evening. Monday in good agreement with the timing and track of the low. Challenging to pinpoint where isolated to widely scattered storms will develop this afternoon. Some of the Hi-Res guidance including SPC-HRRR suggests favored areas north of Lynchburg and Lewisburg and another in southwest North Carolina with the storms tracking to the north and northeast. Any thunderstorms will dissipate shortly after sunset with loss of heating. Winds increase from the ssw, especially just above the surface tonight. Low level is around 60 knots at Boone and Bluefield by Monday morning. Enough low level moisture again tonight for a layer of low clouds. Band of deeper moisture along the front crosses west to east over the region roughly between 15Z/11AM through 03Z/11PM, with the GFS still a couple hours faster than the NAM. This slows down the higher probability of precipitation on Monday morning. Wind shift to the west will behind the front. This looks like late in the day for southeast West Virginia. Still not clear how much pre-frontal precipitation there will be. Questionable how much instability will increase on Monday if most of the mountains start out cloudy and the clouds spread east during the day. Temperatures at mid level not quite as warm just ahead of the front. Bufkit forecast soundings showed enough slow level heating to break the cap by 20Z/4PM Monday across southwest Virginia, northern North Carolina, and southeast West Virginia. Off the 12Z NAM and GFS the forecast Lifted Index values are -4 to -6 with Convective Available Potential Energy around 1500 J/KG with the push east of more stable air in the late afternoon and evening from west to east. Similar to past couple of nights, forecast area will remain in the mild humid air mass and with increasing cloud cover late tonight minimum temperatures will be above normal. Also slightly increased the maximum temperatures for MOnday since front is coming through a little later in the day. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... As of 310 PM EDT Sunday... Forecast models shift a cold front east of our forecast area around 06z (2 AM EDT) Tuesday. In its wake, a brief period of 40-50kt 850mb winds are expected, but pressure rises diminish during the pre-dawn hours Tuesday and the forecast inversion height should keep the strongest winds aloft. Therefore will continue to highlight gusty winds in the mountains in the HWO, but not issue headlines. Breezy conditions continue on Tuesday, and despite cooler 850mb temps, downsloping wind should push temps up to near normal values for early May. Leaned toward the cooler guidance values for lows Wednesday morning as a large high noses into the western potion of the area. A weak return flow Wednesday will bring clouds and an increase in dew points to the southern potion of the forecast area late in the day. Despite weak low level convergence late in the southern Blue Ridge, forecast soundings show a healthy amount of dry air in the low levels, therefore kept a dry forecast in place. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... As of 245 PM EDT Sunday... This period of the forecast will be dominated by a high amplitude upper trof/cut off low that lifts out of the southern plains early in the period, and into New England by the end of the weekend. While there are still some differences in the models with regard to intensity and timing, there is growing consensus that widespread showers and thunderstorms impact our area sometime from Thursday into Friday with upslope showers lingering into Sunday as reinforcing shortwaves rotate southward on the west side of the upper low. Ensemble members seem to be centering around late Thursday/early Friday morning for the best chance for precipitation. The 12Z GFS is showing better run to run consistency, but also aligning more with the 00Z ECMWF with a slightly less amplified upper trof and more northern placement of the upper low. For our area, chances for strong storms appear best when instability and lift align on Friday, but a greater concern may be for the potential for flooding, as NAEFS and GEFS ensembles off the meteorological model ensemble river forecasts show some confidence in the potential for flooding in our area late Thursday/Friday. Will include the mention for possible flooding during this time in the HWO. After being wedged in Thursday, warmest temps for this period will be Friday before below normal temps arrive Saturday into Sunday under the influence of the upper trof. && .AVIATION /04Z MONDAY THROUGH FRIDAY/... As of 705 PM EDT Sunday... Should stay VFR this evening at all sites, then low levels moisten up as southeast to south flow increases with most sites falling to MVFR or lower after 06z, especially near the Blue Ridge, while BLF stays VFR. Timing of front and pre-frontal showers and thunderstorms looks to be starting around 15z BLF/LWB to 17z BCB/ROA and 19-20z LYH/DAN. Ending time will be by 20z BLF/LWB to 23z ROA/BCB and beyond this taf period out east. Thunder chances are good, but could be limited by low level cloud cover. For now will keep VCTS in the TAFs with moderate rain showers with MVFR cigs, with good possibility for IFR cigs/vsbys in heavy downpours. SPC has marginal to slight risk of severe storms, so flying conditions will be turbulent and poor in the region tomorrow. Winds will also be strong from the south tonight into Monday, then stay gusty behind the front Monday afternoon/evening. Extended Aviation Discussion... The cold front will move east of KLYH and KDAN by 03Z bringing the winds around to the southwest then west. Southeast West Virginia may have MVFR upslope clouds into early Tuesday. VFR conditions return Tuesday and will continue under high pressure Tuesday night and Wednesday. A slow moving low pressure system will bring widespread precipitation and sub-VFR conditions to the Mid Atlantic region Thursday and Friday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...AMS NEAR TERM...AMS/WP SHORT TERM...PH LONG TERM...PH AVIATION...AMS/JH/WP
Area Forecast Discussion
National Weather Service Tallahassee FL
914 PM EDT Sun Apr 30 2017 .NEAR TERM [Through Tonight]... The 7 pm surface analysis showed a cold front extending south from a triple point near Saint Louis, MO, through southeast LA, and into the southern Gulf of Mexico. A convective band preceded this front, and a portion of this band was nearing our southeast AL and FL Panhandle zones this evening. The CAMs, including recent HRRR runs, indicate this rain band will make little further progress until late tonight and early Monday, when it (or other developing rain bands) will move into the Dothan and Panama City areas. Still, nearly unpredictable, sudden eastward bulges in this rain band (from organized surface cold pools) could bring periods of rain to the Dothan area ahead of schedule. With 0-6km bulk shear values near 40 kt and MLCAPE values of around 1500 J/kg, there is still a low-end threat of damaging wind gusts in this region overnight. In fact, the 0-1km shear suggests that a brief tornado can not be completely ruled out. Elsewhere, the troposphere remained very dry above 850 mb. While there could be some showers developing overnight well ahead of the slowly- approaching cold front, they are unlikely to acquire much vertical depth given the magnitude of the dry air aloft. && .PREV DISCUSSION [755 PM EDT]... .SHORT TERM [Monday Through Tuesday Night]... The cold front and associated convection will progress eastward across our CWA on Monday. The environment ahead of the front will be less favorable for an organize severe weather threat as sheer and instability will be weaker. However, SPC does still show a marginal risk mainly for our Georgia zones. Drier and cooler conditions will move into the region behind the front Monday night with overnight lows dropping into the mid to upper 50s all but the SE Big Bend (lower to mid 60s). Afternoon highs Tuesday are expected to be mostly in the mid 80s with lows Tuesday night in the upper 50s to around 60. .LONG TERM [Wednesday Through Sunday]... Mainly dry conditions are expected on Wednesday but global models continue to show another deep low pressure system developing and moving into the SE CONUS on Thursday. There will likely be sufficient instability and shear for organized convection, and a chance of severe weather can`t be ruled out. Both models move the system eastward on Friday with dry conditions returning for the weekend. Near average temperatures are expected behind this system. .AVIATION [Through 00Z Tuesday]... MVFR cigs have developed at ECP just east of a slow-moving line of showers and thunderstorms that will move eastward into western portions of our area early Monday morning. MVFR cigs will develop overnight across the remainder of our terminals ahead of this line, and as the showers and storms move eastward MVFR visibility is likely starting around 10-11Z at DHN and ECP, 13-14Z at ABY and TLH, and during the afternoon at VLD. Brief periods of IFR visibility are possible in thunderstorms. VFR conditions are expected to return from west to east during the afternoon-evening behind the line of showers and thunderstorms. .MARINE... Moderate to strong south to southwest winds will continue across the coastal waters through Monday ahead of an approaching cold front. Advisory conditions are expected at times with the worst conditions west of Apalachicola. This will lead to high surf, strong rip currents, and slightly above-normal tides. Much lower winds and seas are expected by mid-week with winds and seas increasing once again on Thursday with the approach of the next cold front. .FIRE WEATHER... No fire weather issues are expected through tomorrow with increasing moisture and likely showers and thunderstorms. RH values could drop to 20-30 percent on Tuesday afternoon along with dispersion values possibly exceeding critical thresholds then, but winds are expected to be too light for red flag criteria. .HYDROLOGY... Rainfall amounts will generally be in the 0.50 to 1 inch range from Tallahassee north and westward with lesser amounts to the south and east. Another system is likely on Thursday with some heavier totals possible. However, the risk of river flooding is low given the recent dry conditions and relatively low river levels. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 71 79 57 86 58 / 30 60 10 0 0 Panama City 73 75 61 81 65 / 40 60 10 0 0 Dothan 69 75 54 85 59 / 60 60 10 0 0 Albany 71 78 54 83 58 / 40 60 10 0 0 Valdosta 70 83 59 85 56 / 20 60 30 0 0 Cross City 70 84 65 84 60 / 10 30 40 20 0 Apalachicola 74 77 62 81 64 / 20 60 10 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through Monday afternoon for Coastal Bay- Coastal Gulf-South Walton. High Rip Current Risk from 6 AM EDT Monday through Monday afternoon for Coastal Franklin. High Surf Advisory until 5 AM CDT Monday for South Walton. GA...None. AL...None. GM...Small Craft Advisory until 8 AM EDT Monday for Coastal waters from Apalachicola to Destin FL out 20 NM-Waters from Apalachicola to Destin FL from 20 to 60 NM. && $$ NEAR TERM...Fournier SHORT TERM...Barry LONG TERM...Barry AVIATION...Lahr MARINE...Barry FIRE WEATHER...Lahr HYDROLOGY...Scholl
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
459 PM MDT Sun Apr 30 2017 .DISCUSSION...(This Evening Through Sunday) Issued at 159 PM MDT Sun Apr 30 2017 Mean troughing will continue over the region through mid next week with a few systems bringing chances for precip. Deep closed low over the southern plains will slowly progress east/northeast. Precip shield from the this system continues to try and shift NW into the FA. However, very dry air in the ll/s continues to fight top down saturation with precip drying up over far eastern scentral SD. Have cut pops there trough tonight, with only a very slight chance mention retained for the SE half of Trip county. Attention turns to the next system which will impact the region tonight into Monday. Sat trends indicate a cu field over SE MT and HRRR has consistently indicated a few shra over northern Campbell county late this afternoon, although dry air in the ll`s will again fight any showers, with virga more likely. Pac system will advect into the region tonight and may support a few rain/snow shra over the western half in a weak FGEN regime. Better chances (although not great) for precip will arrive Monday afternoon. The associated cold pool from this system will support steep ll lapse rates Monday afternoon, generating some small CAPE over the region, enough to support a few showers perhaps a few TS, esp across NW SD. It will also be quite breezy Monday given strong linked flow aloft and expected deep mixing, windiest across NW SD where adv winds are expected. Have added NW SD to a wind adv for this where sustained winds of 25 to 35 mph with gusts to 50 mph are expected, esp in/near any convective shra. A stronger system will then arrive Tues, supporting a decent chance for rain showers and possibly a TS, esp across the SW half. A few snow showers will also be possible Tues evening above 6 KFT with any lingering activity. After Tues, the pattern begins to shift with massive ridging progged over the western CONUS. This will support much warmer conds and dry weather the remainder of the week, with 70s and 80s expected toward the end of next week. Forecast models are progging another large closed low over the west coast next weekend, which would sustain the ridge in place into next week, keeping conds quite warm here. && .AVIATION...(For the 00Z TAFS Through 00Z Monday Evening) Issued At 456 PM MDT Sun Apr 30 2017 VFR conditions are expected for most areas through the period. The exception will be for some MVFR conditions with showers that move through the BLKHLS area from 09-16z, with perhaps spotty MVFR conditions across northeastern WY during the same time. This will be in association with a weak storm system that passes through the area late tonight and Monday. Also with this storm will be gusty northwest winds of 30-45 kt for most areas on Monday. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Wind Advisory from 10 AM to 7 PM MDT Monday for SDZ001-002-012- 013-025-026-031-072-073. WY...None. && $$ DISCUSSION...JC AVIATION...Bunkers