Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/01/19

Area Forecast Discussion
National Weather Service State College PA
1050 PM EST Thu Feb 28 2019 .SYNOPSIS... A series of relatively weak, fast-moving shortwaves within a zonal flow pattern will affect central PA tonight through Saturday. A digging trough over the Miss Valley will spawn a more significant storm system lifting up the east coast on Sunday. The anomalous upper level trough will then pivot across the northeast CONUS next week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Snow is starting to invade the far SW, pretty much on schedule. Just minor tweaks made to the near term forecast. From earlier... The HRRR shows the snow reaching my far SWRN zones between about 8-10PM, and continuing to overspread most of the area by just after midnight. A light to moderate accum is likely over the southern 2/3 or so of the area from late this evening into Friday morning. The best lift will be between midnight and 7 am. But, generally only 4-5 hours at any one location. While snowfall rates will not be intense, with almost no chance of a 1"/hr rate anywhere, the duration of light-moderate snow and SLRs increasing from S-N from 10:1 to 15:1 during that time frame, we should end up with low-end advisory numbers over the southern tier. Have decided to not go any farther to the north with the advisory issued at this time. The speed of the system argues against raising the numbers unless the frontogenetic forcing is better/longer. That said, the NAM and GFS are in lock-step with their 12Z runs and a 4-5" bullseye over Gettysburg. That`s still below warning, but the 2-3" amounts creep northward in that scenario. The far northern tier may get nothing, but should get a dusting according to most model QPFs. The temps aloft get milder, but not above freezing through the night over the Laurels. Thus, late in the night, some sleet or even FZDZ is possible. Sfc temps get lowest in the southern half of the area early in the night, and may rise to near or just above 30F as morning approaches. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... The temps aloft then change little, but we will lose the higher clouds in the morning. Lingering precip will likely be just snow pellets or sleet or freezing drizzle depending on the amount of saturation above. Per soundings, the top of the clouds will likely be super-cooled water around -2C, with colder temps below until close to the sfc. Will just mention the possible --mix in the wx grids, and not in the advy. If these conditions look to be more threatening/last longer, an extension in time to the advy may be necessary. The rest of the day involves only minor warming of <10F in most places. The clouds will likely hang around all day in the central and west, but could show some breaks in the east. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... A pair of fast-moving shortwaves in zonal flow will track over the region Friday night and Saturday, accompanied by some very light snow/rain. Model thermal profiles indicate mainly snow Friday night, with a light coating possible. Any light snow accumulations Saturday would likely be confined to the northern mountains, as warm advection ahead of second shortwave is likely to turn spotty light snow to light rain showers elsewhere. There is increasing confidence in a more significant storm impacting the region Sunday. As upper trough digs over the Miss Valley, all medium range guidance is tracking a developing surface low from the Gulf states northeast to the Delmarva Peninsula by Sunday night. There is no blocking high to our northeast, so don`t anticipate a major storm, but latest model guidance indicates a plowable snow is quite possible over a good portion of the forecast area Sunday PM. With a track over the Delmarva, ptype could be either snow or rain across the Lower Susq Valley. Both the 00Z NAEFS and ECENS show anomalous upper trough pivoting across the northeast conus next week, supporting a high confidence of cold, though probably dry, weather. Ensemble 850 temps 1-2SD below climo and ECM MOS both suggest daytime highs will average around 15F below normal Mon-Wed. && .AVIATION /04Z FRIDAY THROUGH TUESDAY/... The main slug of snow and lowered cigs from a fast-moving system have arrived in JST at 0330z, and will spread eastward through the early morning hours. The most likely impacts are a 5-6 period of IFR/LIFR due to the snow at JST, AOO, MDT, LNS. UNV could also have IFR for a few hours. BFD and IPT will still have a little snow, but any IFR would be limited. The IFR/low-MVFR clouds will then stick around for the day on Friday in most places due to easterly flow. Voted most likely to improve in the aftn is IPT. A wave moving northward along the coast could push a little light precip in from the SE Fri night. A few hours of IFR in snow are possible over the eastern terminals before sunrise Sat. Outlook... Sat...MVFR NW. Mainly VFR elsewhere. Sun...Restrictions likely developing due to snow over most of the area/rain & snow SE. Mon/Tue...MVFR/sct SHSN poss W, No sig wx elsewhere. && .CTP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 8 AM EST Friday for PAZ024>026- 033>036. Winter Weather Advisory until 8 AM EST Friday for PAZ063>066. && $$ SYNOPSIS...La Corte NEAR TERM...La Corte SHORT TERM...Dangelo LONG TERM...Fitzgerald/Gartner AVIATION...Dangelo/RXR
Area Forecast Discussion
National Weather Service Peachtree City GA
937 PM EST Thu Feb 28 2019 .UPDATE... Latest RAP and Hi-res show the short wave over MS/AL a lot stronger than previous model runs. Hi-Res has the precip moving into west GA around 08Z and spreading across the CWA for the rest of the morning and into Friday afternoon. Latest RAP shows MUCAPEs of 700-800 moving into western GA on the leading edge of the precip. Will adjust pops higher for late tonight and add slight chance of tsra. No other changes planned. && .PREV DISCUSSION... /Issued 243 PM EST Thu Feb 28 2019/ SHORT TERM /Tonight through Friday Night/... A weak frontal boundary continues to stretch from the lower Mississippi Valley to the Mid-Atlantic coast, and has been slowly drifting to the southeast through the day today. Widespread rain ahead of a surface low pressure wave associated with the front is positioned over the eastern portion of the area. Some more scattered showers are also moving into the area from Alabama associated with the surface low. As a result, there is a little more forcing with these showers in comparison to the precipitation from this morning. Instability remains limited but not entirely non-existent, so there remains a slight chance for thunder across north Georgia this afternoon. As a result of the zonal flow aloft, the front is expected to become stationary across the southern portion of our forecast area in central Georgia. Additional mid-level impulses and associated surface waves will move quickly through the area through the early parts of the weekend. These disturbances will not be as organized as the system today, so PoPs are mainly capped at high-end chance, with highest chances focused along the stationary front. Since this frontal boundary is quite weak, very little to no airmass change is expected in the wake of its passage. As such, temperatures through the short term period will remain above climatological normals for this time of year. High temperatures today will be around 3-6 degrees warmer than average and low temperatures will be around 12-18 degrees warmer than average. King LONG TERM /Saturday through Thursday/... Refreshed with the latest NBM, however this yielded no appreciable changes to the current extended forecast trends. Still looking at a wet start to the period for this weekend, transitioning into a drier but much cooler period as we head into the the first half of next week. Chances for wintry mix of precipitation across the far north on the back side of the exiting system early Monday continue to look marginal at best as the onset of the stronger cold advection and the tapering off of the precipitation continue to diverge. Cannot completely rule out a brief mix yet. Medium-range models also showing a trend toward a more rapid transition back toward normal temperatures late in the week as the upper flow quickly flattens once again into a generally zonal pattern across the U.S. 20 Previous LONG TERM Discussion /Friday Night through Wednesday/... The extended forecast begins right where the short term left off...wet. The models have come into better agreement with what is expected this weekend and into the beginning of next week. The weather pattern over North and Central GA begins with moist West to Southwesterly flow which will keep a chance of precip in the forecast through day 5/6. There is no real organized moving across the area. With increased moisture and daytime heating will see some showers and an isolated thunderstorms or two Sat. The next frontal system begins developing over the central and southern plains Saturday and deepening into a closed low over the Ark-la- Tex region Sunday morning. This low moves rapidly eastward pushing increased chances of precip in across the region. There is a bit of instability with this system so continuing with isolated thunderstorm chances Sunday. The main low center continues moving East/NE becoming centered just of the New England coast by 12z Mon. The cold front will push south and east across the state Sunday...exiting the area Monday Morning/Early Afternoon. Temps in the extended stay mainly in the 60s for highs and 40s for lows. Things cool off considerably behind the frontal passage Mon/Tue. It does appear the precip will move out of the area before the cooler air can move in so not expecting much (if any at all) in the way of freezing/frozen precip Monday morning. 01 && .AVIATION... 00Z Update... VFR conditions to start but will become MVFR by 03Z and IFR after 06Z. CIGS will rebound mid to late Friday morning to MVFR and remain MVFR for the rest of the day. Areas of rain exiting the forecast area with isolated to scattered showers remaining. Next system will bring scattered to numerous showers late tonight and Friday morning, exiting Friday afternoon. Winds will remain west to southwest around 5kts or less. //ATL Confidence...00Z Update... Medium confidence. 17 && .PRELIMINARY POINT TEMPS/POPS... Athens 54 67 50 67 / 60 60 20 20 Atlanta 54 65 50 65 / 60 60 30 30 Blairsville 49 61 44 63 / 70 60 20 20 Cartersville 51 62 46 63 / 50 60 20 20 Columbus 57 71 55 72 / 60 60 40 40 Gainesville 52 63 48 64 / 60 60 20 20 Macon 56 70 54 71 / 60 60 30 40 Rome 50 61 45 63 / 50 50 20 20 Peachtree City 54 67 50 68 / 60 60 30 30 Vidalia 58 73 58 75 / 40 50 40 40 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...17 LONG TERM....Baker AVIATION...17
Area Forecast Discussion
National Weather Service Wilmington NC
949 PM EST Thu Feb 28 2019 .SYNOPSIS... A weak front will linger in the region through the weekend with periods of rain expected. Showers and possibly an isolated thunderstorm on Sunday will be moved offshore by a cold front Monday morning. A second, dry cold front will move offshore Tuesday night, ushering in an arctic air mass for the middle of the week. && .NEAR TERM /THROUGH FRIDAY NIGHT/... As of 945 PM Thursday...Light rain continues across much of the Pee Dee region, but is fragmenting as it moves eastward toward the coast. Tonight`s rain has been the product of modest isentropic lift along the 305K theta surface, approximately 12-13kft aloft. As drier air currently across western SC infiltrates this layer look for precipitation to wane as shown by the latest several RAP model runs. Aside from minor tweaks to winds and temperatures, no other significant changes have been made to the forecast. Discussion from 600 PM follows... A solid batch of rain across the Pee Dee region is particularly well depicted by the 18z GFS and latest several runs of the RAP model. Using these two models as a guide I have increased PoPs across the interior sections of the eastern Carolinas to 90-100 percent through late this evening, with the odds of measurable rain across the Wilmington/Cape Fear area slipping below 50 percent. The culprit for lower coastal PoPs appears to be a slug of dry air behind a backdoor cold front that dropped southward along the NC coast this afternoon and is now moving south through the Grand Strand area. In addition to dropping dewpoints, this boundary serves as the leading edge of stronger easterly winds which may last for another few hours before diminishing overnight. Changes with this forecast mainly center on adjusting rain chances, with no significant changes made to overnight lows. Lows should still end up in the upper 40s across most of SE North Carolina, and lower 50s elsewhere. Discussion from 300 PM follows... Somewhat moisture laden zonal flow remains in place through the near term period as intervals of light rain showers are expected. At the surface a backdoor front will meander east to west across the area complicating the temperature forecast as well as the wind directions. Overall regarding pops the highest values occur this evening with the first system with a break Friday morning. Rain chances increase once again later Friday late afternoon and early evening before dropping off by early Saturday. Opted for the warmer MAV numbers through the period with regards to temperatures based on last nght`s overall performance but confidence is low. Some early morning fog is also possible again although with more cloud cover expected the extent should be more limited. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... As of 300 PM Thursday...Wave of low pressure will move farther off to the northeast early Sat leaving a front draped just south of forecast area across SC. A deeper W-NW flow Sat afternoon should bring enough dry air to allow for some brief sunshine to push high temps into the 60s. Clouds will return overnight Sat as warm front and southerly winds develop. This will keep temps closer to 50 most places. && .LONG TERM /SUNDAY THROUGH THURSDAY/... As of 300 PM Thursday...Mid to upper trough will dig down toward the western gulf helping to pull a warm front on shore and north over the Carolinas on Sunday. Expect increasing southerly winds in the low levels as sfc winds come around from on shore to SE and eventually southerly as wave of low pressure develops and moves up from the southwest. This should give us a decent shot of rain late Sun into Mon as stronger dynamics combine with increased moisture to produce showers and potential for iso thunderstorms Sun aftn into Sun evening. The cold front will push through on Monday with dry air making its way into the eastern Carolinas. The broad mid to upper trough will remain maintain a westerly flow through Mon night as a shortwave traverses the area. Kept slight chc of pcp, but expect more in the wave of clouds through early Tues. Much colder air will move in late Tues into Wed as a deep NW flow develops and strong high pressure builds in. This will give a push of Arctic air into the area with temps in the 20s for lows by Wed and Thurs and high temps only in the 40s for mid week. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... As of 00Z...Predominantly VFR at the moment, with MVFR visibilities within heavier rain areas. Expect ceilings to lower to MVFR across the area from south to north later tonight. Early morning fog possible, particularly inland and Myrtles, but have only indicated MVFR fog as cloud cover should limit radiational cooling. Possibility of IFR ceilings at all terminals overnight into tomorrow morning, but not much confidence in this so have kept terminals MVFR. Tomorrow afternoon could see lift to VFR, or several changes between MVFR and VFR. Current precipitation in our area will exit the region around 8z, with rain chances increasing again tomorrow afternoon. Winds will be tricky due to front across the area, and its movement over the next 24 hours. Mainly east/southeasterlies tonight with some coastal gusts, becoming predominantly southerlies tomorrow afternoon. Extended Outlook...Unsettled weather through the weekend, with sub-VFR conditions possible each day. && .MARINE... As of 945 PM Thursday...Wind speeds are finally becoming to come down along the Cape Fear coast where buoys and piers are showing gusts in the 19-23 kt range. Seas at the nearshore Wrightsville Beach CORMP buoy had built to 6 feet between 6-8 PM, but are also showing the start of a diminishing trend. If all works out the Small Craft Advisory can come down on schedule at midnight. Discussion from 600 PM follows... A backdoor cold front dropped south along the NC coastline this afternoon and is now in the Myrtle Beach/Grand Strand area. Easterly winds behind this boundary have increased to 15-25 kt, and a short duration Small Craft Advisory has been issued for the NC coastal waters as far south as Little River Inlet. CORMP buoys 41064 (Lejeune offshore) and 41037 (Wrightsville Beach offshore) continue to report gusts in the 25-30 knot range, while winds at the pier at Wrightsville Beach are recently gusted to 23 kt. Models show the strongest winds should occur only for the next few hours, with improving conditions overnight. The boundary should slow as it dips into the Georgetown vicinity later this evening, then will turn around should be drifting north again late tonight into Friday. In response to the higher winds, seas are well above previous forecasts near and north of Cape Fear. Buoys are reporting 5 feet nearshore and 7 feet offshore across Onslow Bay, but closer to 3 feet south of Cape Fear where wind speeds have been lighter much of the day. Discussion from 300 PM follows... Forcing remains challenged for the coastal waters as there are boundaries and systems to be had, just not overly potent ones. Perhaps the highest winds and seas will accompany a backdoor front/northeast surge this afternoon and evening as seen on visible satellite imagery. Northeast winds of 15-20 knots briefly and mainly over the North Carolina waters will kick seas up to 3-5 feet briefly as well. Beyond this a weakening northeasterly flow will give way to a southerly flow then southwesterly later Friday ahead of the next system. Both winds speeds and seas will drop back in magnitude Friday. Wave of low pressure will move farther off to the northeast early Sat leaving a front draped just south of forecast area across SC into or just south of local waters. This should leave a NW to N flow Sat coming around to the E then SE as a warm front pushes toward the coast as it eventually lifts north on Sunday. Southerly winds will increase through Sun into early Mon ahead of cold front which will move through the waters on Monday. Seas will be coming down in light northerly flow on Sat to 2 to 3 ft, but will ramp up late Sun into Sun night as S winds increase up to 15 to 20 kts. Expect seas up to 4 to 6 ft by Sun night and possibly higher. Off shore flow will develop in the wake of the front Mon afternoon allowing seas to subside to 3 to 5 ft and even further down to 2 to 4 ft by Mon night. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...Small Craft Advisory until midnight EST tonight for AMZ250-252. && $$ SYNOPSIS... NEAR TERM...TRA/SHK SHORT TERM...RGZ LONG TERM...RGZ AVIATION...VAO
Area Forecast Discussion
National Weather Service Lubbock TX
538 PM CST Thu Feb 28 2019 .AVIATION... VFR through the evening hours. Low level moisture near Del Rio is expected to accelerate northward this evening bringing with it low clouds and visibility reductions after midnight. While not depicted in this TAF, there is a risk of MVFR at KCDS mainly after sunrise Friday. Computer models have been struggling with clouds/vis as of late--e.g. more fuel for options is better than less. && .PREV DISCUSSION... /issued 339 PM CST Thu Feb 28 2019/ DISCUSSION... A weak surface low has developed across the western South Plains which has resulted in an interesting surface temperature analysis at 3 pm. Temperatures have warmed into the mid 70s across Yoakum and Cochran counties where the surface wind has increased out of the west. From there, temperatures fall into the low 40s in the Rolling Plains with weak easterly surface flow holding temps near 50 to the I-27/US 87 corridor. Again, the shallow cold airmass was not handled well by the synoptic models with the higher resolution TTU WRF and HRRR doing much better in their performance. The frontal zone doesn`t really move overnight remaining near the TX/NM state line. Little moisture advection will take place to the east of the front but all models try to pool some low-level moisture south and west of the front but struggle to bring any of this across the majority of the forecast area. There could be some low clouds in the morning along and south of a Plains to Aspermont where some moisture does push over the old frontal layer. Friday continues to look like a very nice late winter day with model surface wind speed forecasts remaining at or under 15 mph across the area. Only major forecast issue will be how warm temperatures will become across the Caprock where westerly downslope wind could bump up temps; the second being where the frontal zone will end up in the afternoon. Right now the TTU WRF and to some lesser extent the NAM push the front off the Caprock and keep easterly surface winds across the Rolling Plains which looks to be fairly reasonable. That could once again result in forecast highs not being warm enough across the Caprock and too warm across the Rolling Plains. Models bring in the first cold frontal surge after sunset Friday with the front to near the TX/NM state line by sunrise Saturday. The TTU WRF pushes the front all the way to the Sangre de Christo and Sacramento Mountain ranges by that time. This results in complications for the temperature forecast Saturday as the TTU WRF keeps all of the forecast area in the post-frontal airmass while all other models mix the front back east so that the column of counties along the TX/NM border are in the warm air west of the front. We could see another day with surface temperatures looking like they are this afternoon; a difference of 30 degrees or more from west to east across the forecast area. Opted to lean forecast towards the TTU WRF solution as this model has had much better handle on shallow cold-air intrusions across the region. One other change that has taken place is that all models are showing some moisture moving over the frontal zone across the Rolling Plains through the day Saturday. Temperatures should remain above freezing and some light precipitation could develop in the form of rainshowers mainly in the afternoon into the evening. Stronger second frontal surge arrives Saturday night into Sunday morning which could potentially tap into the remaining moisture above the surface through sunrise Sunday. Temperatures will be falling through this window so any ongoing precipitation across the Rolling Plains will gradually transition to a wintry mix early Sunday morning. We do not expect major accumulations at this time but there could be a light glaze on elevated surfaces and vegetation by Sunday morning. Any precipitation will quickly come to an end mid-morning Sunday as much drier air filters in behind the cold front and the frontal zone deepens with time to help push elevated moisture out as well. High temperatures could be reached early in the morning with a gradual fall or holding steady near freezing. The cold dome will remain in place through Monday keeping highs near or below Freezing across all but the western South Plains where surface winds may veer around to southerly and help warm them into the mid 30s. Morning lows potentially could be quite a bit below model guidance depending on how low wind speeds are. If we see light and variable winds in this kind of airmass, low temperatures across most, if not all, of the forecast area could be in the single digits Monday and Tuesday morning. Temperatures will be slow to moderate but will gradually increase starting Tuesday through the end of the forecast. Strong southerly flow develops on Wednesday helping to boost highs back to near normal but difference are starting to creep in by day 7/Thursday. The ECMWF is bringing in another cold front Thursday which is a total flip from the 00Z run while the GFS keeps southwesterly flow in place. Dry conditions are expected for much of next week. Jordan && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 99/99/26
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
920 PM EST Thu Feb 28 2019 .SYNOPSIS... High pressure will temporarily ridge down the coast from the northeast tonight. A weak area of low pressure will form in the vicinity of the south coast Friday and move north northeast during the day. A weak front will move through Friday night. A strong low pressure system will affect the area late Sunday into Monday. Another low offshore could produce some light precipitation Tue. Cold high pressure will build over the area Wednesday and Thursday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 915 pm Thu...Area of shra to the WSW has been diminishing as high res mdls showed. Will cont slight chc pops deep inland thru 06Z then chc inland to slight chc/no chc coast late...rainfall will be very light. Widespread clouds will cont and expect temps to drop little with lows in the 40s. Prev disc...Unsettled pattern through the short term. The backdoor front to the south will become stationary near the SC/NC border with surface high pressure temporarily ridging in from the northeast overnight. Weak low pressure will form off the south coast by 12Z Friday. 12Z GFS and ECMWF as well as HRRR and RUC, have no precip before 06Z, and only 20-30% PoPs after that generally along and west of Highway 17. Lows will range in the lower to mid 40s throughout, with some upper 40s along the southern Outer Banks. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... As of 315 pm Thu...The area of weak low pressure will lift very slowly north northeast during the day. The 12Z GFS and ECMWF have some slight differences in their surface wind/pressure patterns, and generally followed the GFS solution, though confidence is low. Timing of showers and where highest PoPs will be is therefore difficult to determine, so went with chance Pops throughout the area during the day. High temps also tricky, depending on where southerly winds set up. For now, will forecast lower/mid 60s southwest to upper 50s northeast. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... As of 300 PM Thursday...Unsettled conditions will persist through early next week, then drier but much cooler weather is expected mid through late next week. Friday Night...A fast moving area of low pressure will move to the south of the region producing light rain, mainly in the evening. This looks similar to the past couple of systems in our area with light QPF totals. Saturday and Saturday Night...We will be between weather systems for Saturday into Saturday night as low pressure races away from the area to the east and a southern stream system starts to develop over the western Gulf Region. Will hang onto a slight chance PoP Sat for 1 more forecast cycle though it is now looking like dry weather will now prevail. Expecting mild temperatures Saturday with highs in the upper 50s to lower 60s. Sunday through Monday...Strengthening surface low pressure will move across the NC Piedmont dragging a strong Canadian cold front toward the area Sunday and offshore by early Monday. Deep moisture will be drawn northeast from the Gulf of Mexico with precipitable water values around 1.5" over the area Sun night. Will continue with high likely to categorical PoPs for Sun and Sunday night. Cooler air will arrive in earnest by Monday afternoon. Highs Sun are forecast in the upper 50s to lower 60s and cooler low to mid 50s Mon. Tuesday...The GFS continues to show some potential for wintry precipitation Tuesday as a secondary wave of low pressure forms offshore throwing moisture back over portions of Eastern NC (mainly coastal) where temperature profiles will be marginally cold enough for some light wintry precipitation. The ECMWF continues to be weaker and further offshore with this system and keeps our area dry. Will continue with low chance PoPs and a mention of a mix of -R/-S but confidence is very low that any impactful wintry weather will occur in our area at this time. Highs will be in the low to mid 40s. Wednesday and Thursday...Cold high pressure should build over the area Wed and Thu with upper troughing forecast to develop over the eastern US. Thus, Wednesday and Thu are expected to be dry and cold with highs in the upper 30s to lower 40s Wed and 45 to 50 Thu. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Short Term /through Friday/... As of 605 PM Thu...Very little change from prev fcst. VFR thru evening with high pressure ridging into the area. Moisture will increase in low lvls after 06z and expect cigs to lower to MVFR then likely reach IFR around 12Z. Any rain thru the night looks very light with minimal impacts to vsbys. Low clouds look to persist thru the day Fri with moist ENE flow as a front/trf conts near cst. Rain chcs appear to ramp up in the aftn as better moisture and forcing spread in ahead of a short wave. Long Term /Friday night through Tuesday/... As of 300 PM Thursday...With a fairly good coverage of rain Friday night, periods of sub-VFR conditions are expected to continue. Sub VFR ceilings could continue into Sat morning then prevailing VFR Sat afternoon and night as we are forecast to be mostly dry as we will be in between systems. Deep moisture returns to the region later Sunday into early Monday with widespread sub VFR conditions likely. Tuesday weather will depend on track of offshore low pressure, but expecting mainly VFR conditions at the TAF sites at this time. && .MARINE... Short Term /Tonight and Friday/... As of 915 pm Thu...NE winds cont 10 to 20 kts N and 15 to 25 kts S this evening. Seas over outer wtrs 5 to 7 feet. With seas a bit higher than guidance may take a little longer to subside below 6 ft so extended the SCA for cstl wtrs til 4 AM. Prev disc...Weak but complex surface pattern across the marine area through the short term. High pressure will temporarily ridge down into the area from the northeast tonight. Weak low pressure will affect the area Friday. Northeast surge behind the boundary to the south has increased seas to around 5 feet north of Ocracoke. Both NWPS and WaveWatch have 6 foot seas through late this evening in the Oregon Inlet to Ocracoke zones, so will issue a SCA through 06Z. Northeast winds will decrease this evening to 10-15 knots. Light east to southeast winds forecast for Friday. Long Term /Friday night through Tuesday/... As of 300 PM Thursday...Relatively quiet marine conditions are expected through Sunday morning with winds at or below 15 knots and seas at or below 4 feet. High confidence in SCA conditions late Sunday into Monday night. Gusty SW winds ahead of strong Canadian cold front will build seas to as high as 8-10 feet Sunday night and early Mon. This will followed by a strong CAA surge behind the front Mon afternoon into Mon night with N winds of 15-25 knots with higher gusts and seas continuing rough at 5-8 feet before subsiding late Monday night. Developing low pressure is currently forecast to be far enough offshore Tue such that winds will be forecast around 15 kt and seas 3 to 5 ft. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...Small Craft Advisory until 4 AM EST Friday for AMZ150-152-154- 156-158. && $$ SYNOPSIS...MHX NEAR TERM...RF/HSA SHORT TERM...HSA LONG TERM...JME AVIATION...RF/JME MARINE...RF/JME/HSA
Area Forecast Discussion
National Weather Service Morristown TN
741 PM EST Thu Feb 28 2019 .DISCUSSION...Early update this evening to tidy up forecast. The previous forecast is still mostly on track, just updating to follow trends of latest HRRR and RUC. Both these models show the current showers progressing east over the next several hours then drying out across the plateau and central valley. Then, both hi- res models show another wave of showers developing off to our southwest and moving back into our area a few hours after midnight. This is in response to another weak short wave moving in. This wave was mentioned in the previous forecast but it is now moving in slightly faster, thus the POP adjustment after midnight. Also added in patchy fog for tonight and tomorrow morning as several ob sites already reporting fog. Tweaked POPs for tomorrow morning through early afternoon as well due to good model agreement with the aforementioned short wave. Increased POPs east of I-40, mainly centered along the spine of the Appalachians. Will send out new zones. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 50 59 44 60 / 60 40 20 10 Knoxville McGhee Tyson Airport, TN 50 58 41 57 / 60 40 30 10 Oak Ridge, TN 47 56 41 57 / 60 30 20 10 Tri Cities Airport, TN 48 58 40 54 / 80 50 30 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$ SR
Area Forecast Discussion
National Weather Service Nashville TN
852 PM CST Thu Feb 28 2019 .DISCUSSION... The afternoon and evening showers have just about cleared the Plateau and the HRRR model is not showing anything overnight. There could be a few sprinkles on the Plateau or across the south so the updated forecast will include this. Satellite imagery and observations are also showing patch fog across middle TN. Included this in the wording with the sprinkles and by the rivers. Otherwise expect cloudy skies with overnight lows in the middle 30s to middle 40s. && .AVIATION... 00Z TAF DISCUSSION. IFR to MVFR conditions ongoing for issuance as we deal with the backside of this current system. While KBNA/KMQY may remain IFR overnight, look for KCKV/KCSV to see several hours of LIFR into the daylight morning hours on Friday. Improvement back to MVFR, but no better, expected by Friday afternoon. Winds will be light and mainly northerly throughout the cycle. && .PRELIMINARY POINT TEMPS/POPS... Nashville 37 49 36 54 40 / 20 10 10 10 60 Clarksville 34 45 33 53 37 / 20 10 10 0 70 Crossville 41 50 36 52 39 / 60 20 20 10 50 Columbia 38 51 36 55 40 / 20 20 20 10 70 Lawrenceburg 39 52 37 56 41 / 20 20 20 10 60 Waverly 35 47 34 54 39 / 20 10 10 10 70 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......12 AVIATION........Unger
Area Forecast Discussion...UPDATED
National Weather Service Norman OK
710 PM CST Thu Feb 28 2019 .UPDATE... Increased cloud cover tonight and decreased temperatures for tomorrow. && .DISCUSSION... Models have been too quick to erode cloud cover. Expectation is for current stratus deck to remain fairly persistent through the night with perhaps some gradual erosion tomorrow. The RAP seems to be the closest to depicting this solution. With this persistent cloud cover and an influx of moisture from the south tomorrow, lowered high temperatures for tomorrow trending closer to the NAM. Day && .PREV DISCUSSION... /issued 539 PM CST Thu Feb 28 2019/ AVIATION... 01/00Z TAFs. Will keep MVFR clouds through the overnight hours from KOUN/KOKC up to KPNC. All but a couple of models are clueless as to westward extent of stratus and the guidance that has a clue keep the clouds in place through at least 15Z, with additional increase from the south over KSPS and southwest Oklahoma terminals tomorrow. Some cigs may dip into IFR range and will amend if needed. The -SN at KOKC primarily due to lake effect regime off of Overholser and Hefner. As winds weekend and veer, this should become less of an issue next few hours. PREV DISCUSSION... /issued 250 PM CST Thu Feb 28 2019/ DISCUSSION... Clouds across the eastern half to two-thirds of Oklahoma are eroding slowly on the western edge this afternoon. Light accumulations of ice yesterday along with weak cold advection is delaying some of the clearing that models indicate. Areas that see clouds dissipate late this afternoon/early evening, may see fog form by late evening/overnight. A south wind will return on Friday which will aid in warmer temperatures, but still below average (most areas). Low clouds should return to parts of southern Oklahoma and western north Texas with variable high cloud farther north. Another front will push across the area late Friday into Saturday, but may struggle to reach southeast Oklahoma, as the initial cold air will be somewhat shallow. Low clouds will increase and thicken above the shallow cold air which may result in area of light rain and drizzle. Most of the area should remain above freezing during the day Saturday, so mainly rain is anticipated. Cold air will deepen late Saturday and especially Sunday, behind a rather quick moving shortwave trough. This feature will also increase lift across the area which is expected to result in a 6-12 hour period of precipitation. Precipitation that develops across northern Oklahoma should fall in the form of sleet or freezing rain, with mainly a cold rain farther south. With the exception of south central and southeast Oklahoma, most areas should see a wintry mix with mainly snow by Sunday morning. Before the precipitation ends Sunday, a transition to freezing rain is possible across south central and southeast Oklahoma. Gusty winds and very cold temperatures will result in rather uncomfortable wind chill values Sunday into Monday. A wind chill advisory may be required for northern parts of Oklahoma during this period. Mainly dry and cold weather is expected Monday through Wednesday. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 20 46 30 36 / 0 0 10 20 Hobart OK 23 44 28 38 / 0 0 10 10 Wichita Falls TX 26 43 39 44 / 0 0 10 30 Gage OK 21 56 20 35 / 10 0 0 0 Ponca City OK 22 44 25 37 / 10 0 0 10 Durant OK 27 39 39 49 / 0 10 20 50 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ 14/11
Area Forecast Discussion
National Weather Service Shreveport LA
911 PM CST Thu Feb 28 2019 .UPDATE... The evening update was issued in order to account for the radar trends and trends in temps as a frontal boundary pushes southeast of the area. A cold front extends from the western Gulf across southern Louisiana and into southern Mississippi. The front is just to the southeast of Jena in LaSalle Parish and is most noticeable by a wind shift from southerly to more northwesterly and a 15-20 degree thermal gradient. A mid-level weak short wave is pushing across Louisiana in a zonal flow and this feature is providing enough forcing for a few scattered showers crossing Grant and LaSalle parishes and even a stray thunderstorm earlier. Elsewhere in the area, abundant low-level moisture in the 1000-800mb layer, confirmed by the 00z SHV sounding, is aiding patchy light drizzle and fog across much of the area, reducing visibilites to 2-3 miles in some locations. Overnight, the front will continue to push off to the southeast of the area with patchy fog and drizzle continuing through dawn on Friday. The RAP relative humidity time-height cross-section indicates that the layer of low-level moisture draped across the region will begin to condense further, confined to the 850-925mb layer by 15z Friday. The upstream GOES satellite nighttime microphysics imagery paired with obs show an area of clearing in central Oklahoma behind the low-level moisture. The HRRR supports this layer eroding from the northwest near dawn, so could start to see some clearing for southeast Oklahoma, extreme southwest Arkansas and far northeast Texas near dawn. Otherwise, low-level moisture will keep cloudy skies overnight with patchy fog and drizzle in place. Overnight lows were adjusted down 1 to 2 degrees north and west of Shreveport based off of recent trends supported by LAMP guidance. Lows tonight will range from the lower 30s in McCurtain County, OK and portions of SW Arkansas to the mid 40s in central Louisiana. /04-Woodrum/ && .PREV DISCUSSION... /issued 605 PM CST Thu Feb 28 2019/ AVIATION... An area of low-level moisture below 6,000 feet will continue to move slowly across the terminals overnight behind a cold front. IFR and MFR ceilings can be expected with visibilities dropping to IFR at times with patchy fog and drizzle. Winds overnight will mostly be light around 5 kts and north-northwesterly across the terminals becoming more westerly by 18Z Friday. Ceilings will lift to MVFR by late morning and prevail into tomorrow afternoon. /04-Woodrum/ PREV DISCUSSION... /issued 402 PM CST Thu Feb 28 2019/ SHORT TERM.../Tonight through Friday Night/ The chance for some spotty showers will continue through Friday and Friday night as the frontal boundary which ushered in all this cold air will eventually stall out and retreat back northward as a warm front late Friday through Friday night. The big question is just how far will the front make it back north during this timeframe as the temperature forecast will be greatly impacted. Highs on Friday are generally expected to be in the mid to upper 50s with overnight lows Friday night falling into the 40s and lower 50s for most locations, but warmer temperatures are possible across our extreme southern zones where the warm front may be able to advance by late Friday night. /19/ LONG TERM.../Saturday through Wednesday Night/ Disturbed zonal flow aloft atop a returning warm front to bring warm temperatures to the srn half of our region Saturday, with rain chances increasing during the evening and overnight. Sharpening temp gradient along the front across N TX/SE OK will provide a focus for tstms Saturday aftn/overnight, a few of which could produce some severe hail. Of greater concern will be tstms associated with the shortwave that begins to move across our region Sunday morning, forcing the cold front ewd along with it. Strong deep-layer shear and moderate instability in the warm sector particularly over N LA/S AR will bring a threat for severe storms with damaging winds and perhaps an isold tornado threat. Storms to push ewd by late Sunday aftn/evening, with flow aloft becoming nwly and high pressure/Arctic airmass building in at the sfc. Unseasonably cold temps and finally some dry weather are on tap for the first half of the work week as that Arctic airmass continues to settle swd. Stuck close to the blends for now, but may see these temps trend even cooler over the next couple of days. Wednesday should bring some relatively warmer temps as sunshine as CAA wanes and abundant sunshine wins out. /12/ && .PRELIMINARY POINT TEMPS/POPS... SHV 40 58 51 64 / 10 10 30 30 MLU 44 59 51 63 / 10 20 30 20 DEQ 32 53 44 54 / 10 10 30 50 TXK 36 54 45 58 / 10 10 30 40 ELD 36 56 45 60 / 10 10 30 30 TYR 35 56 51 64 / 10 10 30 40 GGG 37 57 51 65 / 10 10 30 30 LFK 41 62 57 73 / 10 10 30 30 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 04/19/12