Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/15/19

Area Forecast Discussion
National Weather Service State College PA
1047 PM EDT Sun Apr 14 2019 .SYNOPSIS... Low pressure over the Ohio Valley will track across upstate New York tonight, as the trailing cold front pushes through Pennsylvania. Upper level ridging is expected over the region during the middle of the week, then a slow-moving cold front will likely push into the region late Friday into early Saturday. && .NEAR TERM /UNTIL 7 AM MONDAY MORNING/... Tornado Watch continues for most of the area, but the far NW where the best instability has passed through as the main line of damaging convection pushed past. Still strong shear and some D-CAPE to be dealt with. Many spinning cells thus far, but no specific reports of actual tornadoes. Big line is breaking up a bit, but also accelerating. Thus, the threat for wind damage is still on-going. The threat for tornadoes may be a little lower, now, as the instability has waned, but the threat for tors along/inside the main line remains high. Expect sct shra thru the next few hours in the NW, but action has shifted to the east. Expect the tiny cells over the central counties to fill in and perhaps organize a bit - esp if they are more in the north where the shear is best. Main shortwave which forced the earlier convection in the SE has push most of that to the NE and out of the area. The main line should pass through the far SErn counties by 07-08Z right around end time of the watch. Will trim the watch as necessary. && .SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/... Blustery and much cooler conditions are expected Monday, as strengthening low pressure passes north of Pa. Passage of upper trough will likely produce scattered rain/snow showers across the Allegheny Plateau. However, surface temps should remain too warm for any snow accumulations. A downsloping westerly flow should result in dry weather across the Susq Valley. However, cold temps aloft will likely result in a good deal of stratocu. Bukfit soundings support wind gusts Monday afternoon close to 40kts across southern PA, so later shifts may need to consider a possible wind advisory. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... Left mentioned of some showers in for later Tuesday into Thursday. Much of this time will be dry. The main issue will be another huge weather system by Friday. Showers and some thunderstorms will be associated with this system. For now, just minor adjustments. For later Saturday into early next Monday, the risk of showers tapers off. GFS and EC still different from run to run and day to day, on how the upper level trough may split apart, and dig southeast. This will make a difference on how things linger past Friday. Either way, not looking quite as cold as it did several days ago. Thus the chance of any snow showers on the back side of the storm is less now. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... A line of showers adn thunderstorms is making its way across central PA from 02Z until 10Z. It has caused a period of IFR and lower cigs and vsbys in thunderstorms. Expect this to occur at all TAF sites at times overnight. Light showers are out ahead of the line which will mainly affect IPT and MDT. An area of showers behind the front will drop cigs and vsbys Behind the front which is occurring at BFD. Westerly flow will pick up with a period of gusts to 30-40 mph Monday along with ceiling restrictions that will be mainly confined to the western/northern terrain. .Outlook... Mon...AM Rain and restrictions. Becoming windy. Tue...Trending VFR; winds subsiding. Wed-Thu...Chance of a shower. Mainly VFR. Fri...Widespread restrictions likely with showers and thunderstorms. && .HYDROLOGY... Main line has passed through the NW, but additional rainfall is possible. Watch only goes through 2 AM, and rain poss thru then. Will hold onto it there. Showers finally popping up in between the SErn cluster and the big line, but not much QPF just yet. HRRR continues heavy rain with the line, and threat for heavy rain still goes for most of the night for the SE. Prev... 0.75-0.90" of rainfall through the day today over the NW has things very wet and many of the smallest waterways are likely high/nearly full. The line of convection to the west is advancing slower to the east than the elements are moving N/NE. They could also receive more than one thunderstorm this evening/early tonight. Felt the threat was much higher than FFG may reflect there with most of the water not accounted for in the guidance. Plus, we are solidly in the SLGT risk of excessive rain per WPC guidance. The southeastern counties got some heavy rain and patchy flooding two days ago, and they are starting to pick up some rain now. There is some thunder embedded in the stuff moving up from MD/VA. HRRR paints a few stripes of >1" rain in convection there. The Front and associated thunder/heavy rain does not arrive until late tonight, and we are always wary of overnight convection. The deep 60+KT LLJet is loaded with moisture. 1 hr FFG ranges between one inch and two inches. We will also have to watch out for the Swatara Creek which is running high and is arguably the wettest basin around the state right now. && .CTP WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch until 2 AM EDT Monday for PAZ004-005-010. Flash Flood Watch until 6 AM EDT Monday for PAZ036-056>059- 063>066. && $$ SYNOPSIS...Dangelo NEAR TERM...Dangelo SHORT TERM...DeVoir/Fitzgerald LONG TERM...Martin AVIATION...Ceru/RXR HYDROLOGY...
Area Forecast Discussion...Updated
National Weather Service Peachtree City GA
1020 PM EDT Sun Apr 14 2019 .Update... Line of showers/storms moving through far east central GA and should be out of the forecast area by midnight. Wind Advisory has expired. Winds should remain generally gusty overnight...but remain below advisory criteria. .Previous... .SHORT TERM /Rest of today through Monday Night/... While the first prefrontal wave of precip and embedded severe/tornado potential is exiting over portions of east central Georgia, the next focus will be with possible convective redevelopment along a confluence zone in north GA/central TN. SPC has this area in a meso discussion to where the shear and some increasing instability with previous clearing could allow for another round of strong to severe storms capable of hail, damaging winds, and tornadoes. The HRRR and Nam Nest models have consistently indicated such convection occurring over the last 2 days of runs. Cannot rule out another Tornado Watch in the next hour or two. Otherwise drier air will build in tonight through Monday Night into midweek as a strong ridge builds in. Baker && .LONG TERM /Tuesday through Saturday/... Forecast looks largely on track with next storm system still in the late Thurs/Friday period and lingering upper trough influence going into the weekend. No changes made and previous discussion follows... Baker .LONG TERM /Monday Night through Saturday/... Extended forecast starts with high pressure over the area, lasting through mid week. Next system moves in late Thursday, and have backed off pops Wednesday given the slightly later model solutions. Strong frontal system looks well organized and brings the next chance for severe storms. SPC already highlighting the area for Day 6 and 7 severe threat risk, and so this system will certainly be the forecast concern through the latter half of the week. A secondary wave swings through the long-wave trough Friday night into Saturday, keeping chance pops in the forecast. High pressure returns to the state late Saturday. Saturday, expect the coolest temperatures for the week, with highs only in the 60s, and lows largely in the mid to upper 40s by Sunday morning. 31 && .AVIATION... 00Z Update... Line of showers/thunderstorms moving into east and central GA will affect KAHN and KMCN within next few hours. After that only expect a few showers overnight across the area. Ceilings should lower to mvfr before 06z and improve to vfr after 14z. Gusty SW winds overnight will become NW and gusty after 12z. //ATL Confidence...00Z Update... Medium on overnight cigs. High on all else. && .PRELIMINARY POINT TEMPS/POPS... Athens 76 45 67 45 / 100 30 0 0 Atlanta 76 45 66 48 / 100 30 0 0 Blairsville 71 37 59 40 / 100 40 0 0 Cartersville 78 42 65 45 / 100 30 0 0 Columbus 79 47 71 48 / 100 20 0 0 Gainesville 74 44 64 45 / 100 30 0 0 Macon 79 47 69 46 / 100 20 0 0 Rome 77 42 66 44 / 90 30 0 0 Peachtree City 78 43 68 45 / 100 20 0 0 Vidalia 83 52 72 49 / 80 40 0 0 && .FFC WATCHES/WARNINGS/ADVISORIES... none. && $$ SHORT TERM...41 LONG TERM....31/Baker AVIATION...41
Area Forecast Discussion
National Weather Service Grand Forks ND
1009 PM CDT Sun Apr 14 2019 .UPDATE... Issued at 1007 PM CDT Sun Apr 14 2019 First area of showers moving into the DVL basin with a few more showers west of that toward Minot and also extending toward Bismarck. HRRR and other CAMs indicate best shot of showers tonight remain along and north of Hwy 2...but did extend pops a tad farther south. But precip is falling from mid cloud deck so not expecting more than a few hundredths. Temps as clouds thicken and precip moves in will be above freezing and suspect more liquid than anything, but some wet snow mix may occur. && .SHORT TERM...(This afternoon through Monday night) Issued at 323 PM CDT Sun Apr 14 2019 Showers associated with WAA ahead of mid level shortwave trough beginning to move from western ND into central ND. This activity should overspread our CWA tonight, with main track favoring locations north of Highway 2 closer to axis of better/more organized forcing. Potential for showers still extends across much of our CWA, but overall would be more isolated. P-type still most likely rain or snow and any snow accumulations would be light (less than one inch). This activity should exit the region to our east/northeast Monday morning, with dry westerly flow overspreading our CWA Monday. Where precip occurs temps may hover just above freezing, and winds may also help mix low levels even in areas with good clearing holding overnight lows up. Temps will be quite mild Monday and depending on clearing, strength of westerly flow, and impact of lingering snow pact, locations as far east as the Red River could reach 60. Areas over snow pack may still hover in the 40s Mon. .LONG TERM...(Tuesday through Sunday) Issued at 323 PM CDT Sun Apr 14 2019 Another storm system is posed to bring widespread rainfall to the region by the middle of the work week. Luckily, temperatures will see a warming trend through the week that will promote rainfall over snow. Additional light rain chances are possible by the end of the week and into the early weekend. Tuesday... Fairly benign weather is anticipated on Tuesday as temperatures continue to warm into the 50s and low 60s across the region. Cloud cover will gradually increase Tuesday night into Wednesday. Wednesday through Thursday... Model guidance has come into fairly good agreement that another high- amplitude upper level trough will propagate into the central Plains by Wednesday. Unlike the previous storm that brought snow to the region last week, weaker differential vorticity advection over a deepening lee cyclone will allow for an overall weaker and more elongated surface low as it moves into the eastern Plains/upper Midwest region. The implication of this is that sub-freezing arctic air is not as likely to surge southward as in the previous storm. This, along with a relatively warmer airmass already in place, will help promote mainly rain as the likely precip type. Rain is expected to begin across the Dakotas Wednesday morning before spreading eastward through the day as broad synoptic lift associated with the main upper level wave overspreads the region. Generally, rainfall chances and amounts increase southward from the international border towards the ND/SD/MN tri-state region. Recent deterministic guidance, and several GEFS members, are beginning to suggest relatively high QPF amounts (in the 0.5 to 1 inch range) are possible roughly south of the Highway 2 corridor. These higher QPF amounts are being driven by a strong 850-700mb frontogenesis signal and may be augmented across the tri-state area by weak mid-level instability. Given the synoptic pattern this scenario is possible, but the placement of the higher QPF amounts will largely be dependent on the track of the low. Although rain is going to be the primary precip type, a bit of snow can`t be ruled out as the system slowly exits the region from west to east on Wednesday night/Thursday morning. This snow is mainly being driven by diurnal cooling and likely won`t lead to any impactful accumulation amounts. Temperatures rebounding into the 50s on Thursday will help melt any potential snow accumulation. Friday through Saturday... Temperatures will once again slowly climb back into the upper 50s and low 60s for Friday and Saturday. Upper level ridging over the Plains on Friday will help direct an upper level shortwave over the Canadian Rockies and across the international border region. An attendant surface trough/weak cold front will likely propagate through the region late Friday and into early Saturday. Scattered rain is likely along this front, but widespread heavy rainfall is not expected at this time. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 647 PM CDT Sun Apr 14 2019 VFR thru the pd as extensive high and mid level cloud cover move thru in association with the 500 mb vort. South-southeast winds will remain mostly in the 10 to 20 kt range thru the night, though lighter BJI area. && .HYDROLOGY... Issued at 950 PM CDT Sun Apr 14 2019 North Dakota Tributaries: The Sheyenne River at Kindred and the Maple River at both Enderlin and Mapleton are expected to rise to a secondary crest later this week as snow melt will combine with expected rainfall. River levels will continue falling at West Fargo and Harwood along the Sheyenne River. Rainfall forecast will be monitored closely in the coming days as there is the potential for heavier rainfall for the southern portions of the Red River Valley towards mid week. Northwestern Minnesota Tributaries: The latest forecast for northwestern Minnesota Tributaries has the South Fork Buffalo River at Sabin rising once more to a secondary crest this week. This is mainly in response to the melting of snow from last weeks winter storm. Additionally, we will see rises along the Buffalo at both Hawley and Dilworth as well as the Red Lake River at Crookston. The Wild Rice, Sandhill, and Marsh Rivers are all on track to continue falling through the week. It is worth noting that another weather system will be bringing precipitation chance back to the region, thus there is a possibility for additional rises or a slowdown in the fall of river levels. Red River and Wild Rice at Abercrombie: The Red River is expected to continue slowly falling this week at Halstad. All other Red River locations will see rises in response to the snow melt from last weeks winter storm. Secondary crests are expected from Wahpeton to Fargo, then in East Grand Forks. Oslo will see a very slow fall through the week with river levels only falling about half a foot over the next 7 days. Further north, crests have not yet been reached and river levels will continue to rise through weeks end. Additional water contribution from expected rainfall this week could cause additional rises across the area, especially for the southern Red River Valley. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. Areal and river point flood warnings continue across portions of the region. Refer to the latest flood warnings and statements for detailed information on specific locations. && $$ UPDATE...Riddle SHORT TERM...DJR LONG TERM...AM AVIATION...Riddle HYDROLOGY...Lynch
Area Forecast Discussion
National Weather Service Grand Rapids MI
1102 PM EDT Sun Apr 14 2019 LATEST UPDATE... Update .SYNOPSIS... Issued at 326 PM EDT Sun Apr 14 2019 - Snow will continue tonight...heaviest northwest of a South Haven to Alma line. - Sunny Monday. - Thunderstorms likely Thursday, some potentially strong. && .UPDATE... Issued at 1100 PM EDT Sun Apr 14 2019 Deformation zone snow is hanging tough with occasional flare ups of heavier intensities still being seen on radar. Latest HRRR guidance still shows snow pulling away after 06Z and ending late tonight, so additional accumulation should be generally an inch or less. However with temperatures falling below freezing overnight hazardous travel conditions may continue through the morning commute despite the snow being over. UPDATE Issued at 541 PM EDT Sun Apr 14 2019 Based on snowfall reports and the 88D precip/snow accumulation algorithm, a band of rather heavy snow accumulations in excess of 6 inches has set up this afternoon from the Muskegon/Whitehall areas, northeast across Newaygo and White Cloud, to Big Rapids and Stanwood, and up toward Clare. Muskegon has reported 2 inch per hour snows in their ob, and the concern moving forward this evening with still more snow to fall and northeast winds gusting to 25 mph is that the power outage potential will be increasing over the next few hours within this area. Just in the last hour or so the Consumers Energy outage map shows outages increasing in Muskegon and Newaygo counties. Fortunately, per latest short term model guidance, the heaviest snows should be exiting to the northeast in the next couple hours, followed by generally lighter snowfall rates after 00Z. && .DISCUSSION...(This evening through next Sunday) Issued at 326 PM EDT Sun Apr 14 2019 A moderate band of snow stretches from north of STL across the central CWA to Saginaw Bay. Mixed rain and snow is falling over the southern cwa. An inch or so of really wet slushy snow has created hazardous driving conditions with many accidents reported on area highways. The snow is going to continue through midnight or so as low pressure moves across the Ohio Valley. Additional accumulations of an inch or two are possible after 00z, even over the southern cwa where the rain will turn to snow toward evening. A warm front moving north Tuesday will generate some light rain which may mix with freezing rain and/or snow over the northeast cwa. This precipitation will linger into Wednesday as the warm front becomes nearly stationary. The main weather story for the week, though, is the potential for a strong low to develop over western Wisconsin. There are a lot of dynamics with this storm such as a strong accompanying short wave, 50kt llj, and strong shear. Instability has been a limiting factor recently as thunderstorms tried to develop, but it may not be Thursday. After the stationary boundary lifts north as a warm front, Li`s fall to -2c and surfaced based cape rises to around 500 j/kg as the trailing cold front moves east during peak heating. Given strong inflow of moisture from the Gulf and we may see an abundance of thunderstorm activity Thursday afternoon and a few of the storms could be strong and perhaps severe across the southern cwa. The ecmwf/gfs show the low lingering over Michigan through Saturday so light rain showers look possible. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 802 PM EDT Sun Apr 14 2019 Widespread IFR and icing threat continuing this evening, with areas of LIFR vsbys in snow/heavy snow around MKG and GRR. Precipitation is still mostly rain south and east of GRR, but expected to mix with and change to snow shortly before ending later this evening. IFR conditions giving way VFR early Monday from northwest to southeast. North-northeast winds 15-25 kts becoming northwest and diminishing to around 10 kts overnight. && .MARINE... Issued at 326 PM EDT Sun Apr 14 2019 The gale warning will expire at 00z for the southern marine zone. A small craft advisory will be in effect for the entire nearshore through 12z Monday and for the southern 3 zones through mid day due to higher waves. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory until 4 AM EDT Monday for MIZ037>040- 043>046-050>052-056>059-064-065. LM...Small Craft Advisory until 8 AM EDT Monday for LMZ847>849. Small Craft Advisory until 2 PM EDT Monday for LMZ844>846. && $$ UPDATE...Meade SYNOPSIS...04 DISCUSSION...04 AVIATION...Meade MARINE...04
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
827 PM EDT Sun Apr 14 2019 .SYNOPSIS... A strong system will bring more widespread storms to the area on this afternoon and tonight, with severe weather possible. Dry weather conditions will prevail through mid-week, with showers and thunderstorms returning at the end of the week with an approaching cold front. && .NEAR TERM /THROUGH MONDAY/... As of 800 PM...Have allowed Tornado Watch #62 to expire over our NC PIedmont. Meanwhile, a line of tstms along a sfc cold front continues to slowly cross the western third of the FA within Severe Tstm Watch #66. That watch was expanded a little east across the rest of our NE GA zones and also Anderson and Greenville counties in SC. The latest HRRR hints that an uptick in the convection is likely over the next 2-3 hours, thus the watch expansion. From there, instability should really start to decrease, and the low-level jet max seems to be racing east ahead of the slow-moving convective line. With that said, cannot rule out another Severe Tstm Watch at 02z (10 PM), if the convection continues to look robust. Otherwise, the wind headlines look okay. Not seeing as many gusts in the 35-40 kt range as earlier, but plan to let the headlines ride. PoPs are lining up well with the convection so far. The front should clear the area to the east by around 06z. Gusty NW winds and rapidly dropping temps expected behind the front in the high terrain late overnight. Strong gradient winds along and immediately behind the front will continue especially across the mountains, but will let the High Wind Warning expire at 02z. Gap winds overnight coming off the higher elevations may lead to some minor wind concerns in the Piedmont. Moisture and CAA may result in some light snow at the higher elevations, but not enough for an advisory of any sort. Much cooler tonight behind the front, a good 20 degrees cooler than this morning`s lows, and freezing in the mountains (frost/freeze program not turned on up there). Strong CAA will result in highs 5-10 degrees below normal on Monday, breezy conditions continuing. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... As of 215 PM EDT Sunday: Ridging aloft and high pressure near the surface will provide quiet weather with mostly clear skies and light winds through the short term, Monday night through Wednesday evening. Surface high pressure over the region Monday night will likely support below normal lows in the mid 30s to mid 40s, warming nicely into the upper 50s (mtns) to 60s to near 70 east of the mtns Tuesday under nearly full April sunshine. Surface high pressure pushing off the east coast will allow weak southerly return flow Tuesday night into Wednesday. This along with high clouds possibly streaming through the region will support lows in the mid 40s to possibly mid 50s by early Wednesday morning rising well into the 70s and possibly near 80 (depending on amt of high clouds) Wednesday afternoon. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... As of 220 PM EDT Sunday: ...From previous discussion due to ongoing severe weather... Latest guidance continues to come into better agreement on the timing of another approaching cold front towards end of the work week. Per latest guidance, with sfc high pressure offshore, sfc low over the central Plains will continue to strengthen as it very slowly propagates northeastward towards the Upper Midwest through into Friday. Aloft, southern stream trough will strengthen and deepen as it shifts eastward, joining the northern wave energy and becoming an upper closed low. Nearly expanding across most of the CONUS, the center of this feature will eject into the upper Midwest into Friday night, while at the sfc, the parent low`s cold front will already be in the process of pushing eastward through the FA in the morning hours. Given how far out this feature is, there`s still plenty of time for temporal and spatial changes, but overall anticipate shower and thunderstorm chances to return as early as Thursday. Ahead of the front where the Southeast will once again be well in the warm sector, it`ll be another Spring-like system on tap for the last weekend in April, with dewpoints nearing 60 degrees and high temperatures on Thursday ranging from the mid 70s to near 80 degrees south of the I-85 corridor and in and around the Charlotte Metro area. Behind the exiting system, upper troughing will linger and swing overhead Saturday and Saturday night, with lingering precip along the TN border possible, where elsewhere, a drying trend will be already occurring. Though temperatures will drop to below normal behind the exiting front, do anticipate temperatures attm to remain above freezing in the mountains, thus do not anticipate any mention of snow attm. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... At KCLT and elsewhere: Main concern is timing line of slow-moving convection still west of the Upstate TAF sites at time of 00z TAF issuance. The latest high-res models seem to be initializing this well, and so the timing of tempo groups for TSRA is based mostly on them. Not as confident how well the activity will hold up by the time it reaches CLT, but will keep a tempo for the 03-05z time frame for now. Once the front pushes thru to the east, winds will shift to SW, then WNW Monday morning. Winds will be gusty thru the evening, with some lull possible overnight, then becoming gusty again late Monday morning (although not as strong as earlier today). Skies should clear out, with some stratocu banking up against the western slopes of the mountains, which are not expected to reach KAVL. Outlook: VFR conditions will continue through mid-week. The next cold front bringing moisture and potentially strong storms will approach the area late Thursday thru Friday. Confidence Table... 00-06Z 06-12Z 12-18Z 18-00Z KCLT High 91% High 100% High 100% High 100% KGSP High 93% High 100% High 100% High 100% KAVL High 89% High 100% High 100% High 100% KHKY High 89% High 100% High 100% High 100% KGMU High 96% High 100% High 100% High 100% KAND High 98% High 100% High 100% High 100% The percentage reflects the number of guidance members agreeing with the scheduled TAF issuance flight rule category. Complete hourly experimental aviation forecast consistency tables and ensemble forecasts are available at the following link: && .GSP WATCHES/WARNINGS/ADVISORIES... GA...Wind Advisory until 10 PM EDT this evening for GAZ010-017-018- 026-028-029. NC...Wind Advisory until 10 PM EDT this evening for NCZ033-035>037- 048>053-056>059-062>065-068>072-082-501>510. High Wind Warning until 10 PM EDT this evening for NCZ033- 048>052-058-059-062>064. SC...Wind Advisory until 10 PM EDT this evening for SCZ001>014-019. && $$ SYNOPSIS...SGL NEAR TERM...ARK/TDP SHORT TERM...Munroe LONG TERM...SGL AVIATION...ARK
Area Forecast Discussion
National Weather Service Wilmington NC
1039 PM EDT Sun Apr 14 2019 .SYNOPSIS... A cold front accompanied with showers and a few thunderstorms will clear the Carolina coasts late in the pre-dawn Mon hrs by before daybreak. Dry high pressure will follow and build across the area late Monday through the midweek period. The next cold front will slowly cross the Carolinas late this week or early Sat with a round of showers and thunderstorms possible. High pressure will follow and build in from the southwest late next weekend thru early next week. && .NEAR TERM /THROUGH MONDAY NIGHT/... As of 1005 PM Sunday...The Tor Watch has been cancelled. Tstorm Kinematics are quite engaging but unfortunately the instability is lagging. Some additional dynamics are progged to push across the FA overnight, but will it be enough to overcome and work with what little instability remains given the low level SE-S flow from off the Atlantic the past few days. There may be enough elevated instability to work with as that next area/line of convection and associated dynamics pushes east. Nevertheless, still agree showers and a few storms will be possible during the pre-dawn Mon hrs and thus will not completely lower POPs. The latest HRRR and HiResW continue their increased coverage re- intensification of tstorms overnight but just downstream and east of the ILM CWA and waters. Have "re-done Pops and Wx for late this evening and overnight and have also tweaked overnite min temps by a degree or 2 at most. Previous.................................................... As of 700 PM Sunday...TOR Watch in effect for the entire land based ILM CWA thru 06Z. Based on latest 88d trends and HRRR model runs, POPs and WX have also been updated to account for the best chances and locations to experience T and especially T+ during the TOR Watch period ending at 06Z. The earlier thick Cirrus overcast and the low level SE to S flow (ie. Maritime Stable Atlantic Air) of the past 1 to 2 days, have combined to limit instability across the FA. Basically it`s a Low Cape and High Shear Environment with discrete cells with Tornadic signature type storms being favorable, hence the Tor Watch in effect. Once the influence from this low level stable maritime air is overcome somewhat from additional upstream dynamics, an increase in tstorm coverage should fire up with models hinting this possibly occurring during the pre-dawn Mon hrs, possibly after 06Z. At and after 06z, the majority of this convection should be downstream of the ILM CWA. With HRRR and HiResW indicating this possibility. Previous....................................................... As of 300 PM Sunday...An approaching cold front will move through the area tonight preceded by scattered showers and thunderstorms. A few storms could become severe with the potential for damaging winds and large hail. The rain will taper off from west to east overnight and should come to an end completely by about daybreak Monday. Clearing skies and cooler weather is on tap for Monday and Monday night. Minimums tonight should fall to the upper 50s to lower 60s. Temperatures won`t rebound a lot on Monday with highs expected to reach the upper 60s to lower 70s. Mins Monday night will fall the the mid 40s to around 50. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... As of 300 PM Sunday...High pressure overhead on Tuesday, will shift off the coast overnight. Mid to upper ridge will be aligned up through the Southeast with plenty of dry air and subsidence to keep a rain-free forecast. Light and variable winds will come around to the S as return flow develops around the high. The cooler air mass in place will modify with the warmer and more humid air making its way in Tues night into Wed. Dewpoint temps in the 30s Tues aftn will end closer to 50 by Wed morning. Overall, expect dry weather with just below normal temps and plenty of sunshine, making it feel warmer in the sun and cooler in the shade on Tues. Temps should reach into the lower 70s most places on Tues and fall into the low to mid 50s Tues night. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... As of 300 PM Sunday...Air mass will warm and moisten in southerly return flow around exiting high pressure Wed into Thurs. This will introduce aftn cu and only a very low end chc of a localized shower on Thurs as ridge holds overhead most of the day. Overall, expect cirrus to filter out the full sunshine and some flat cu developing. Moisture will increase further on Fri as air mass destabilizes in warm and humid air mass ahead of front. This cold front will march across the Carolinas Fri into Fri night. Southerly winds will begin to increase as gradient tightens as early as Thurs eve. Expect fairly widespread clouds and decent coverage of shwrs and thunderstorms through Fri and could see some strong to severe thunderstorms. Cold front moves off the coast with drier and relatively cooler air moving in through Saturday, but deep mid to upper trough still remains west of the area. As this shifts east later on Sat, clouds and a chc of shwr will return with dry air to follow for Sunday as high pressure builds in. Temps will warm into the 80s most places Wed through Fri with overnight lows on the warm side, remaining in the 60s. Temps will begin to cool on Sat, back below normal but will warm again on Sun in bright sunshine. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... As of 0Z....Currently MVFR ceilings at coastal terminals (with occasional IFR at MYR and CRE) and VFR inland. Scattered storms across our area tonight before main line of precipitation moves across shortly after midnight with cold front passage. Chance for thunderstorms, and slight chance some storms may become severe. Non-convective low level wind shear is likely at coastal terminals between 2z and 7z, with southerly winds at 2000 ft approaching 50kts. After cold front passage, skies will clear out and remain clear for rest of TAF period. Strong southerly surface winds overnight will veer to westerlies by late tomorrow morning. Extended Outlook...VFR through Thursday. Showers possible Friday. && .MARINE... As of 1015 PM Sunday...SCA for all waters continues. Have maintained the changes made to winds/seas from the prior update. The changes for this update are primarily to the POPs and associated Wx for the remainder of the this evening thru the overnight across the area waters. Previous................................................ As of 715 PM Sunday...The stable low level maritime Atlantic air will keep convection from becoming too widespread as well as reaching or surpassing SVR thresholds. For that reasoning, the TOR Watch does NOT include the local ILM waters. Have continued the SCA overnight thru much of Mon as the sfc pg continues to tighten ahead of the cold front, with it`s passage slated before daybreak Mon. S to SW 15 to 25 kt G30 will veer to the West after FROPA and further veer to the NW Mon afternoon. With CAA added to the mix, the waters will see a bit more gustiness in the wind field. Previous.................................................. As of 300 PM Sunday...Frisky conditions are expected over the waters tonight with SW winds of 20 to 25 KT with higher gusts. Isolated to scattered thunderstorms may produce locally higher winds and waves. Winds will shift to the west shortly after daybreak Monday and become NW toward evening before becoming northerly late Monday night. Speeds will diminish from 20 to 25 KT Monday morning to 10 to 15 KT late Monday night. Seas will build to 6 to 9 feet overnight tonight before subsiding to 3 to 5 FT by late Monday night. High pressure will move overhead on Tue then shift offshore Tue night. Offshore flow at the start of the period will gradually weaken with winds veering from north to east Tue. Reduction in wind speeds will allow seas to fall from 3 to 4 ft Mon night to 2 to 3 ft Tue and 2 ft or less Tue night. South to southwest flow Wed and Thu with high off the Southeast coast. Gradient will keep speeds 10 kt or less through early Thu with seas 2 ft or less Wed, but increasing to 2 to 4 ft through Thurs aftn as gradient begins to tighten with approach of cold front. Expect a further increase in winds and seas Thu night into Fri with SCA conditions developing around daybreak on Fri. Seas may reach up to 8 to 10 ft in the outer waters by Fri night in stiff southerly flow up 20 to 30 kts. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...Beach Hazards Statement from 6 AM EDT Monday through Monday evening for NCZ110. MARINE...Small Craft Advisory until 5 PM EDT Monday for AMZ250-252-254- 256. && $$ SYNOPSIS...DCH NEAR TERM...DCH/RAN SHORT TERM...RGZ LONG TERM...RGZ AVIATION...VAO MARINE...
Area Forecast Discussion
National Weather Service Key West FL
1013 PM EDT Sun Apr 14 2019 .CURRENTLY...(Through Late Evening) Mostly clear skies and warm, muggy conditions exist over the Florida Keys right now, with temperatures in the lower 80s at 10 pm, and dewpoints in the mid 70s. Satellite imagery and surface obs nicely depict a cold front trailing from the Big Bend of Florida down to the Yucatan Peninsula, with upper level support provided by the upper trough extending south from the Great Lakes region. A few showers are currently developing over our far western waters west and south of the Dry Tortugas. However, the 00z KEY sounding shows a dry and stable layer between about 4,000 and 8,000 feet, which will inhibit showers from reaching the Lower Keys until very late tonight. Indeed, the last two runs of the HRRR have changed their tune by now keeping these showers away from the Lower Keys late this evening. So does the 18z NAM. Will be counting on this initial wave of showers to dissipate about the time they move east to Rebecca Shoal or the Marquesas Keys. .SHORT TERM...(Late tonight through Tuesday night) Upper level support will outrun the cold front over the Gulf late tonight and Monday. Will be relying on shallow lift created by low-level convergence near the front to squeeze out any showers. A few showers could move across the Keys starting as soon as the pre-dawn hours on Monday. Any chance for showers will end as the cold front pushes across the islands during the early afternoon. Shallow lift should be insufficient for any lightning. Once the front passes, northwest then north winds will develop and become gusty on Monday PM over the Lower and Middle Keys, where land-based gusts near 20 mph are expected. The post-frontal air mass that passes by the Keys on Monday night and Tuesday will not be substantially cooler, but it will be a bit drier. Dewpoints will bottom out around sunrise on Tuesday in the less muggy mid 60s. PW values will drop well under 1" until Wednesday, which makes a dry forecast from Monday PM through Wednesday virtually assured. After Tuesday morning, surface winds will quickly become easterly, bringing a return of higher surface dewpoints, though the depth of surface-based moisture will remain shallow under a strong upper high. && .LONG TERM...(Wednesday through Sunday) From Previous Discussion: A western North Atlantic ridge extending across the Gulf coast States and the Sunshine State will slowly shift south and southeastward, as a cold front moves eastward in the Gulf of Mexico on Thursday into early Friday. With that, moisture will be on the increase so isolated pops will be inserted for the island chain beginning Wednesday night with chance pops starting Thursday night. Thereafter, medium range guidance and ensemble members differ somewhat on the exact timing of the cold front clearing our region, so middle of the road chance pops will be carried despite MOS guidance being higher until certainty increases. For next weekend, it appears cooler and drier air will prevail for our entire region. Stay tuned as changes are likely. && .MARINE... Gentle to moderate southeast breezes this evening will clock around out of the southwest and west near 10 knots well after midnight. Winds will increase and clock around to northwest to north on Monday afternoon following a cold front. Fresh north breezes northwest of the Lower Keys will build significant wave heights over the deep southeast Gulf waters as high as 6 feet on Monday evening. Moderate to perhaps fresh north to northeast winds overspread most of our marine district by early Tuesday morning. Moderate to fresh winds with the higher winds on the Straits of Florida are anticipated during the middle of this week. && .AVIATION... A few layers of clouds between 020 and 080 will develop and increase late this evening and overnight, in advance of a cold front that will pass the terminals around 17z-19z on Mon. The possibility of a weak shower peak around sunrise and is reflected in the TAF with VCSH. Following frontal passage, a sudden increase in north wind will occur, posing cross-wind issues on the east-west runways at EYW and MTH. Northerly gusts of 15-19 knots appear most likely on Monday PM. Skies will also clear out following front passage. && .CLIMATE... In 1940, the daily record low temperature of 58 degrees was recorded in Key West. Temperature records date back to 1872. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...Haner Aviation/Nowcasts....Haner Data Collection......Chesser Visit us on the web at Follow us on Facebook and Twitter at:
Updated for 00Z Aviation Forecast Discussion below.

&& .PREV DISCUSSION... /issued 322 PM CDT Sun Apr 14 2019/ DISCUSSION...Surface analysis this afternoon places a surface low over Southwest Ohio with a trailing cold front over East Tennessee then back through Alabama and the Florida Panhandle. Cloudy skies persist over the Mid-South this afternoon as GOES-16 satellite trends still indicate an upper level low gradually rotating through the Middle and Lower Mississippi Valleys. KNQA WSR-88D radar trends along with area observations suggest some light rain showers or sprinkles occurring across portions of West Tennessee as of discussion. As of 3 PM CDT, temperatures across the Mid- South are predominantly in the 40s at most locations with a few lower 50 degree observations near the MS/AL border. Clouds should begin to decrease across the forecast area tonight as the upper level low pushes away from the Mid-South into the Ohio and Tennessee Valleys. Clearing skies combined with light to nearly calm winds along with temperatures dropping into the middle 30s with decent radiational cooling is expected to be conductive for the formation of frost tonight, predominantly across West Tennessee. Consequently, I`ve issued a Frost Advisory across the above mentioned area. Rain free weather is expected to persist across the Mid-South through Tuesday with temperatures averaging slightly below normal. Long term models continue to indicate an upper level trough moving through the Central/Southern Plains into the Middle/Lower Mississippi Valleys Wednesday night into Thursday. The potential for strong to severe thunderstorms still look possible during this timeframe and have left mention in the Hazardous Weather Outlook. This will continue to be monitored in subsequent forecasts with potential threats being mentioned as this potential event draws closer. Stay tuned... Some wrap around moisture associated with the upper level trough axis will bring a chance of rain showers for Friday into Saturday along with a return of slightly below normal temperatures. CJC && .AVIATION... 00Z TAFs Broken high MVFR ceilings will give way to clear skies as thermal trof around FL050 lifts east this evening, and surface temps diurnally cool. A surface pressure ridge center will track east across southern MS overnight, with an inverted ridge axis extending north through the Midsouth. Under clear skies, expect calm surface winds for at least part of the overnight. Short range guidance from the HRRR suggests no fog, but MKL NAM Bufr sounding shows some potential for fog. Given saturated soils, climatology suggest at least a chance of MVFR VSBY developing at MKL and perhaps TUP. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...Frost Advisory from 1 AM to 8 AM CDT Monday for Benton TN- Carroll-Chester-Crockett-Decatur-Dyer-Gibson-Henderson- Henry-Madison-Obion-Weakley. && $$