Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/15/18

Area Forecast Discussion
National Weather Service Wakefield VA
1059 PM EST Fri Dec 14 2018 .SYNOPSIS... Low pressure approaches from the southwest tonight, then tracks across the local area Saturday. An upper level trough will remain over the area Saturday night through Sunday. High pressure returns Monday through Wednesday. The next cold front approaches from the west Thursday. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... As of 1045 PM EST Friday... With a break in the rain to just very light rain or drizzle across portions of south central VA where the melting snowpack is interacting with rising dew pts, have received some reports of near zero vsbys in some areas. Have issued a short-fuse Dense Fog Advisory to account for this (through 2 am Sat for now). Would expect to see vsbys improve a bit as the rain fills back in so will re-assess closer to 2 am the need for an expansion in time and possibly areal coverage. Latest high res data continues to indicate the heaviest and steadiest rainfall overnight will be mainly east of I-95 as the low approaches from the sw late. Can`t rule out some elevated thunder across the se late as that area is progged to get warmed sectored as the triple point low crosses the area. Min temps for the night have been reached as readings have steadied out or risen over the past few hrs. In addition, areas of fog will accompany all this making for a rather messy night ahead. Thus, adjusted the grids based on the current radar and model trends. Temps by morning should range btwn 40-45 across the Piedmont to the upr 50s-lwr 60s along the sern coastal areas. Flood watch remains in affect through late Saturday. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... As of 215 PM EST Friday... Small area of lo pres along the coastal front will be exiting the VA Capes Sat morning while main occluded lo pres tracks into the TN Valley. The coastal lo pres will push a frontal boundary back S (invof the coast) by afternoon. Otherwise...models showing nebulous sfc pres pattern over the FA Sat...which suggests keeping conditions cloudy. PoPs will remain quite high in the morning...then RA will begin to shift to the ENE (and PoPs lowering in the afternoon). Will keep Flood Watch for the balance of the day...but it will likely be allowed to end sooner once RA coverage/intensity lowers Sat afternoon. Will continue w/ patchy/areas of FG in the morning. Highs around 50F W to the l-m60s in far SE VA-NE NC (though temperatures likely drop off during the day). Upper level system approaches from the W Sat night...w/ most models showing steady pcpn having ended for most areas. Will maintain low chance PoPs (~30%) S and high chance to likely PoPs (far N (50-70%). Cooler, with highs ranging from the m-u40s N/NW to the m50s SE. Area of SHRAS may linger across the E and NE Sun low pressure departs the region. 12Z/14 NAM a bit stronger w/ the departing lo pres just off the srn NJ/DE coasts Sun evening/night. At this time...appears cold enough air behind the storm likely arrives after pcpn exits so no change in ptype expected (late Sun/Sun night) on the ern shore. Highs Sun in the m-u40s N to the l-m50s SE. Dry wx returns Mon under NW flow aloft as sfc hi pres moves through Midwest. Highs in the u40s N to m50s in NE NC. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 130 PM EST Friday... Hi pres will be sliding across the region Mon night into Tue night...then offshore Wed. Dry/seasonable wx is expected. Amplification of trough aloft through the Great Lakes Thu then to the E Fri...pushes a cold front into/across the local area by the end of next week. Will increase clouds/PoPs Thu into Fri. Lows Mon night from the u20s W to the l-m30s at the coast. Highs Tue ranging through the 40s. Lows Tue night in the m20s inland to the l30s along the coast in SE VA-NE NC. Highs Wed in the m-u40s N to the l50s S. Lows Wed night ranging through the 30s. Highs Thu in the l-m50s N to the m-u50s S. Highs Fri mainly 50-55F. && .AVIATION /04Z SATURDAY THROUGH WEDNESDAY/... As of 645 PM EST Friday... Rain continues to overspread the area this evening ahead of an apprchg low from the sw. Cigs quickly drop to IFR in rain and fog. Areas of LIFR Fog is possible as well. The low tracks across nern NC/sern Va Sat morning. Thus, rain/fog continue through the morning hrs. Thunder was left out of the forecast attm, but thunder is psbl early Sat morning at ECG/ORF as the low tracks across the area. The rain becomes more sporatic in nature Sat aftrn, but IFR CIGS remain. Wind Shear was added to RCG forecast after midnight. Otw, e-ne winds tonight, become S-SE along the coast late tonite then w behind the low Sat. RIC stays ne through the forecast period. OUTLOOK... An upper level trough lingers over the area into Sun...IFG CIGS along with periodic rain/fog likely to continue. Drier wx with improving conditions arrive late Sun night into Mon and will then persist through midweek. && .MARINE... As of 1015 PM EST Friday... Went ahead and hoisted an SCA for the lower Bay south of New Point Comfort and the Currituck Sound until 6am Saturday. Quick surge of onshore winds as gradient ramps up ahead of approaching low pressure overnight. HRRR and new 00z NMM/ARW each show a brief 3-5 hour window of marginal SCA winds. As of 310 PM EST Friday... A pair of low pressure systems will impact the local waters tonight through the weekend. E-SE winds of 5-15 kt (up to 20 kt ocean)are expected thru tonight. Seas are expected to increase to 5-6 ft across all ocean zones tonight, and SCAs remain in place to account for this. Winds remain below SCA levels for the most part, but a brief period of gusts to ~20 kt is possible tonight over the srn bay/Mouth of the bay. Since wind gusts will be right around advisory criteria and relatively short lived, opted to not issue an SCA for the bay attm. Winds decrease and become more variable over most areas by Sat PM as the aforementioned sfc low becomes elongated and moves offshore and a second low pressure center (coupled w/ a closed upper low) moves over the mountains of WV. However, winds are expected turn to the NE over the northern ocean zones and remain in the 10-20 kt range through out much of the day on Sat due to the W-E oriented area of (elongated) sfc low pressure center centered from WV to SE VA. Therefore, seas likely remain elevated over the coastal zones through the weekend, but may drop below 5 ft from late Sat night-Sun S of Cape Charles. Winds then become more W/NW by Sun evening (and increase to 15-20 kt) as the secondary area of low pressure moves offshore. Winds turn more to the NW on Mon evening through Tue AM and increase to ~20 kt over the bay/~25 kt over the ocean as an upper trough moves from SE Canada to New England and a shot of colder air moves into the Mid-Atlantic from the NW. Seas increase to SCA levels over the srn ocean zones Sunday night, and remain elevated over northern areas. Elevated seas could potentially continue through Tue, so current SCAs that go thru 6am Sun may need to be extended/additional SCAs may need to be issued in the coming days. && .HYDROLOGY... As of 1015 PM Friday... RA/runoff will eventually pose river flood threat along the James...Appomattox and Chowan Rivers late in the weekend into early next week. Our latest multimedia briefing at contains the latest information. Please also refer to the latest River and Lake Summary (WBCRVDAKQ). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...Flood Watch through Saturday afternoon for NCZ012>017-030>032- 102. VA...Flood Watch through Saturday afternoon for VAZ048-060>062- 064>069-075>090-092-093-095>098-509>525. Dense Fog Advisory until 2 AM EST Saturday for VAZ065>068-079- 080-513. MARINE...Small Craft Advisory until 6 AM EST Sunday for ANZ650-652-654- 656-658. Small Craft Advisory until 6 AM EST Saturday for ANZ632>634. && $$ SYNOPSIS...ALB/LKB NEAR TERM...LKB/MPR SHORT TERM...ALB LONG TERM...ALB AVIATION...MPR MARINE...JDM HYDROLOGY...
Area Forecast Discussion
National Weather Service La Crosse WI
538 PM CST Fri Dec 14 2018 .SHORT TERM...(This evening through Saturday night) Issued at 216 PM CST Fri Dec 14 2018 Early afternoon satellite imagery showed pesky fog/stratus remaining in place across southeast Iowa and into far south-central Wisconsin. As for the forecast area, plenty of sunshine was finally seen as the fog dissipated by mid-day. The clear skies will last into tonight and combined with the light winds could lead to fog development once again, along with lows in the teens or even single digits in favored cold spots. Many hi-res models are on board with the fog, but notably the RAP and HRRR keep visibility up over the forecast area. Looking at those particular models` soundings, they struggle to saturate the low levels and instead tank the dewpoint as fast as the temperature. However, given all the melting that will likely occur the rest of this afternoon, thinking dewpoints are probably underdone. Overall it does look like a very shallow fog, much like last night, and given pretty good model agreement (aside from the HRRR/RAP), keeping fog mention in the forecast. May even need another Dense Fog Advisory for parts of the area again tonight. Ridging will be firmly in place on Saturday, with temperatures generally reaching the mid 30s to lower 40s. Could even sneak out a few more degrees in some spots depending how quickly any fog dissipates, as mostly sunny skies are expected for the afternoon. .LONG TERM...(Sunday through Friday) Issued at 216 PM CST Fri Dec 14 2018 Sunday will see temperatures in the mid 30s to lower 40s once again. A weak shortwave trough is still progged to move through the area during the day, but the associated surface low and precip remain north of the Canadian border. Northwesterly flow behind the trough will then lead to a brief cool down for the start of the work week, with highs in the upper 20s to mid 30s on Monday. Upper level ridging then works back in for Tuesday, leading to temperatures back in the 30s for mid-week, but another shortwave trough looks to dig southeastward toward the area sometime Wednesday into Thursday. Still some differences in timing and location of precipitation. The ECMWF remains consistent in amplifying the wave a bit more than the GFS and brings accumulating precipitation across much of the forecast area, while the GFS holds much of the precipitation closer to a surface low over Lake Superior. Either way, any precipitation looks to move off to the east by Thursday afternoon, with northwest flow remaining in place for the end of the work week and into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 538 PM CST Fri Dec 14 2018 Lower confidence fog forecast tonight as compared to previous nights. We did indeed finally see things clear out today, with just a little mixing out of the boundary layer and moisture, though some snow melt did also occur. Light winds will remain in place overnight with high pressure nearby, and have to believe that all spots will see some reduction in visibility to MVFR or IFR levels in lighter fog. However, confidence honestly is not very high with regard to where or if any widespread dense fog will develop. LSE may actually have the best shot given its valley location, as RST is likely to see some stronger southerly winds up to 10 knots later tonight, though quite simply put, we`ll just have to watch trends through the evening to see how visibility trends unfold. Suffice it to say that changes to the forecast are likely over the next 6-8 hours as trends become more clear. The good news is that any morning fog will again be replaced by solidly VFR conditions/clear skies after it burns off, with winds from the south to southeast 10 knots or less. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...CA LONG TERM...CA AVIATION...Lawrence
Area Forecast Discussion
National Weather Service Charleston SC
1019 PM EST Fri Dec 14 2018 .SYNOPSIS... A storm system will shift over the region tonight into Saturday. Dry high pressure is then expected to prevail through next Wednesday before another storm system possibly affects the area late next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... The deep upper low to our west has shifted northeast into Mississippi this evening while water vapor satellite imagery shows the feed of deep moisture continues to stream into eastern GA and SC. Latest 00Z NAM12 guidance indicates two areas of enhanced rains to watch out for overnight. The first is progged to shift north along and inland from I-95 over our inland zones where we have seen lesser rainfall amounts today. One inch plus amount are possible but the heavier of this rain should move into the SC midlands and Western Pee Dee by 09Z. The second area of enhanced rains will likely work up and along coastal zones overnight, fueled by strong low level convergence and theta-e advection. There is a chance that rains become more convective along coastal SC where a Flash Flood Watch was maintained in the Charleston Tri-County area. The new NAM shows 1-2 inch rainfall amounts will occur just off the coast but we have noted the latest HRRR recently showing increasing rounds of more substantial rains for the Central SC coast. Since high tide was around 1 AM this morning, any rainfall rates of 1/2 to 1 inch per hour could cause further problems and this was our reasoning for keeping the watch alive. We suspect conditions will tend to improve by sunrise as the main band of convergence moves up the coast and north of the area. Temps will remain steady or slowly rise overnight and there could be patches of fog just about anywhere overnight. At this time, conditions do not favor a build-down fog potential given forecast wind fields. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... Saturday and Saturday night: Aloft, the large upper low centered near the Mississippi and Alabama state line will gradually lift northeastward and into the southern Appalachians during the day. Then overnight, the upper low will continue to pass by to the north shifting into the Mid Atlantic. At the surface, the surface low and attending cold front will shift east of the forecast area in the morning and precipitation will come to an end in the morning as it does so. Model time heights and soundings show mid and upper level moisture stripping out in the morning, ending the heavy rain threat early. Showers could linger through around midday, mainly along and east of I-95. Sky cover will improve late in the day and sun could begin to come out by the late afternoon. Despite being behind the cold front, temperatures will not cool significantly with highs ranging in the upper 60s in most locations. Overnight, a dry forecast is in place with lows in the mid to upper 40s. Sunday through Monday: Aloft the upper low will move further away from the region before the next trough approaches from the northwest and passes through on Monday. High pressure will slowly move across the central CONUS, beginning to build in from the west on Monday. Dry air will encompass the area and highs in the low 60s are expected. Sunday night lows are forecast to fall into the low to mid 40s. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... High pressure from the Great Lakes to the Deep South should move east and offshore into mid week with a coastal trough developing off the Southeast U.S. coast. This could lead to a few coastal showers but there will be a potential for more significant rainfall Thursday and/or Friday as another storm system possibly affects the region. Either way temperatures should remain above normal through the period. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Widespread rains should continue overnight at both terminals with MVFR conditions along with periodic IFR conditions, especially later on in the wake of a surface low. The forecast remains tricky in our stable warm sector regime and a pinning down the lowest conditions overnight in time and space remains a lower confidence scenario. Conditions will improve on Saturday as rains taper off and cigs eventually lift to VFR late in the day. Extended Aviation Outlook: VFR should prevail Saturday night through Wednesday. && .MARINE... Tonight: A surface wave will move across the region overnight with winds tending to veer to southwest. Speeds will increase over warmer offshore waters but will continue to struggle mixing down over the stable cool shelf waters. This evening we continue to hear some reports of fog around the Savannah River Entrance and earlier issued a Marine Weather Statements. SCAs will remain in effect overnight, mainly for seas. Conditions will be quite unfavorable with widespread moderate to heavy rains, low vsbys in rain and fog and elevated seas. Saturday through Wednesday: Conditions will steadily improve across the local waters on Saturday as a cold front pushes well to the east. Elevated seas will linger into Saturday night, and the ongoing Small Craft Advisories will steadily come to an end through Sunday morning. Thereafter, conditions will remain below Small Craft Advisory thresholds through the middle of the week. && .HYDROLOGY... A Flash Flood Watch will remain in effect for the Charleston Tri-County overnight given already saturated grounds from previous rainfall. River and stream levels are also likely to rise. Several rivers across the area are already at/above flood stage, and could rise higher into next week. Other rivers could approach or reach flood stage too by early/mid next week. && .CLIMATE... New record rainfalls for the date have been set at North Charleston and Downtown Charleston. No record yet at Savannah, but rains continue to fall. Record reports will be issued at midnight. Current rains as of 1015 PM EST: KCHS - 2.89 (new record) and KSAV- 1.40 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...Flash Flood Watch through Saturday morning for SCZ044-045-050- 052. MARINE...Small Craft Advisory until noon EST Saturday for AMZ352. Small Craft Advisory until midnight EST Saturday night for AMZ350. Small Craft Advisory until 6 AM EST Saturday for AMZ354. Small Craft Advisory until 6 AM EST Sunday for AMZ374. && $$ NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE... HYDROLOGY... CLIMATE...
National Weather Service Jackson KY
1020 PM EST Fri Dec 14 2018 .UPDATE... Issued at 1020 PM EST FRI DEC 14 2018 Updated the forecast into Saturday morning mainly to adjust the PoP grids in order to better incorporate the current lull and the development of more pcpn late tonight based on the latest near term guidance. Have also added in the current obs and trends for the T and Td grids. These updates have been sent to the NDFD and web servers along with a freshened set of zones. UPDATE Issued at 645 PM EST FRI DEC 14 2018 23z sfc analysis shows low pressure moving into the Tennessee Valley from the southwest. This is spreading a healthy and sustained band of rain showers across the northwestern three- quarters of the CWA with up to an inch falling as this area slowly lifts through the CWA for most places. Downsloping on the east to southeast winds of 5 to 10 mph is likely helping to limit the showers in the far southeast this afternoon and evening. Do still expect a bit of a lull later this evening and into the first part of the night as the better upper level support moves off to the northeast. A stray thunderstorm remains possible with the heaviest of the showers, but most places will miss out. Currently, with the wet environment, temperatures are fairly uniform across eastern Kentucky and generally in the upper 40s to low 50s with dewpoints within a degree or two of 50 degrees most places. Have updated the forecast through the rest of the evening mainly to fine tune the PoPs with the first batch of showers slowly winding down to a lull - in line with the latest HRRR guidance. Did also incorporate the current obs and trends into the T and Td grids. These updated grids have been sent to the NDFD and web servers. A zone update will be issued later this evening to better time the best shower chances after midnight - and to remove evening wording. && .SHORT TERM...(This evening through Saturday night) Issued at 419 PM EST FRI DEC 14 2018 The afternoon surface analysis reveals an area of low pressure progressing across the Lower Mississippi River Valley and south to southeast flow streaming into eastern Kentucky. In the upper levels, we are still watching a mature vertically stacked closed low that will slowly progress northeast into the Tennessee and Ohio Valleys. This flow is out of the southeast and is leading to some downsloping in the southeast part of the region, and therefore lesser precipitation amounts and even dry in some cases. However, upper level divergence, a low level jet across the Tennessee Valley and some frontogenetical forcing aloft is leading to decent rainfall across the heart of the CWA down to the Lake Cumberland region. We will continue to see moisture stream out of the gulf, with fairly anomalous PWAT values of greater that 1 inch pouring into the region. This will lead to additional rain showers and even a few thunderstorms developing under some marginal instability this evening into tonight. The models do hint at a decent deformation zone developing mostly north of the region overnight into Saturday, and this will lead to better chances of seeing higher QPE values along and north of I-64. This is where we have forecast amounts of 1.5 inches, with isolated higher amounts possible if thunderstorms develop and depending on where the better deformation zone lines up. Saturday the vigorous upper level low and surface low will progress across the Tennessee and Ohio Valleys. This will lead to the aforementioned deformation band across northern Kentucky and will likely lead to a overall lull in rain showers across areas along and south of the Mountain Parkway early Saturday. Then another area of showers will track out of the Tennessee Valley and into eastern Kentucky by Saturday afternoon and evening. This will lead to another round of QPE, with amounts generally around 0.25 to 0.50. After this, not much in the way of moisture will be left and we will see energy begin to get transfered to the developing low along the east coast Saturday night. .LONG TERM...(Sunday through Friday) Issued at 419 PM EST FRI DEC 14 2018 Cold core low will be migrating just east of the Commonwealth Sunday morning with post-frontal/upslope induced rain showers continuing across far eastern Kentucky into the afternoon. A secondary upper low will be diving southeast across the Great Lakes late Sunday into Monday. This northwest flow regime will keep temperatures in check, with highs Sunday and Monday generally in the upper 40s. Relatively normal ridge/valley temperature splits look likely as surface ridging builds in from the west, allowing winds to subside and skies to clear. Upper ridging and subsequent rising heights moving east from the nation`s midsection will bring dry weather to eastern Kentucky for early-mid week. However, Tuesday will bring near to below normal temperatures as surface ridging across the Ohio Valley keeps a cool dome locked in and negates any appreciable warm air advection during peak heating. Temperatures look to rebound into the 50s Wednesday as this surface ridge moves east off the mid-Atlantic, allowing for warmer southwesterly flow to take hold of eastern Kentucky downwind of cyclonic flow spanning the southern Plains to upper Midwest. The tandem of northern and southern stream systems will spell increasing rain chances for Thursday into Friday, with perhaps enough cold air spilling in on the backside of the system for a little snow. A great deal of uncertainty remains on this potential, regarding whether the northern or southern stream system becomes dominant or if they phase. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) ISSUED AT 715 PM EST FRI DEC 14 2018 CIGs will slowly decrease to MVFR through the evening for the ones that have not already dropped down there with the showers. Have also allowed for some VLIFR CIGs along with fog as the heavier showers pass at a couple of the sites through late evening - via a tempo group. Expect the prevailing conditions to drop to IFR or lower at times later tonight into Saturday for most sites. Looking for a lull in the pcpn for Saturday morning before the shower chances tick up in the afternoon - though have allowed for CIGs to come up to mid range MVFR. Winds will remain light through the TAF period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...DJ LONG TERM...GUSEMAN AVIATION...DJ/GREIF
Area Forecast Discussion
National Weather Service Miami FL
724 PM EST Fri Dec 14 2018 .AVIATION... Main concern through TAF cycle will be approaching frontal boundary. Current timing has it reaching KAPF 07Z-08Z and east coast 10Z- 12Z as it breaks apart. All locations may see additional -SHRA ahead of this line. TSRA threat looks minimal at this time, so have kept VCSH. Slow movement will keep -SHRA in vcnty through TAF cycle. SSE winds 8-12kts overnight, becoming SSW with pre-frontal boundary, gusty SW after 16Z tomorrow. && .UPDATE... A few anticipated changes with this evenings update. Mainly to back off PoPs this evening. The front is slow moving and no significant showers are even close to South Florida. The HRRR continues to show most of the activity holding off until 03-05z, or between 10pm and midnight est. So, dropped PoPs across the area, and even removed mention this evening for the east coast until after 03z, and even then it is only a slight chance. Kept chance PoPs for the east coast after 06z, although it may be closer to dawn before showers get near the Atlantic coastal areas. The Gulf coast has better chances earlier, as the front is approaching from the west. There is still the possibility of some general thunderstorms for the area through tomorrow evening as well. && .PREV DISCUSSION... /issued 352 PM EST Fri Dec 14 2018/ DISCUSSION... Big stories for the week are the cold fronts tonight and another at the end of the week. however, they do not look to bring as cold an air mass as the last front. The current setup starts with a 500mb and surface low are over Louisiana, with a cold front nearing the western edge of the Florida Panhandle, stretching southward well into the Gulf. Models are indicating the low will be fairly slow moving, moving over Alabama by around 03z, or 10pm est, tonight, and the cold front still not through the Tallahassee area. There also appears to be a pre frontal surface trough that is well ahead of the main front. This trough is what may initiate some stronger showers and storms over Central Florida. There is also a 250mb jet that may be helping to amplify convection in central Florida. However, these dynamics should stay well north of South Florida, keeping us fairly quiet for this evening and mainly showers and some general thunderstorms over night. Looking at the HRRR, convection may not even make it into the western lake region until are dawn. There may also be a few showers over the Atlantic waters, and possibly the Atlantic coast. Most likely the forecast is too aggressive with pops this evening, even though it is lower than the model guidance. Would not be surprised if the overnight hours are mostly dry. So confidence, even in the short term is pretty low. That said, only brought low end chance PoPs over the the eastern South Florida area late this evening. Would not be surprised if evening updates backed off on these numbers. The front itself will creep across the area through the day tomorrow, and should be exiting the Atlantic coast sometime in the late afternoon hours. This would keep chances for showers and thunderstorms in the forecast for the day tomorrow. Behind the front, high pressure is forecast to build in for tomorrow night into Sunday. The cooler air mass will take its time moving into the area. Highs on Sunday are forecast to be somewhat cooler, in the 70s across the area. Lows Sunday look to be around 10 degrees F cooler than Saturday morning. By Monday, the cooler air advects in and lows across the region will range from the upper 40s in the western lake region, to the upper 50s for the Gulf coast, to around 60 along the Atlantic coast. The western Miami to Palm Beach metro areas are forecast in the upper 50s. The dry air will take a little longer to move in, not significantly dropping until Monday, when they are forecast to be in the 50s. The coolest day looks to be Monday, then a gradual warming trend for the middle of the week, under high pressure. At least until late Wednesday night, into Thursday morning. Overnight Wednesday, a 500mb trough moves off the Texas coast. Ahead of it, the models are indicating some cyclogenesis over the the western Gulf. Models are hinting it may interact with the frontal boundary, from tomorrows cold front, which looks to stall over Cuba, and stretch well back towards southern Texas. The developing system should lift this front to the north, as a warm front on Wednesday night spreading showers well out ahead of it. As this system develops over the Gulf, there is a second system over the hudson Bay in Canada. This system is associated with a much strong upper level low that will absorb the southern system. As it does, the system becomes an extended cold front stretching from new England down to Cuba. This system looks to likely bring just another round of mainly showers to the area at this time, although some thunderstorms may need to be added in as it gets closer in time. This front is currently progged to move more quickly and exit South Florida by next Saturday morning. MARINE... A cold front is forecast to slowly move through the area from tonight through tomorrow night. This will shift the wind to the northeast by Sunday morning. However, the wind is not forecast to be above any advisory criteria, or even enough to build seas above 5 feet in the offshore Gulf waters of South Florida. For the Atlantic seas are only forecast to build to around 3 feet in the Gulf Stream on Sunday. So, while small craft should exercise caution, no advisory will be issued at this time for tonight or tomorrow, and the current advisory will be cancelled with this update. Behind this front, high pressure is forecast to build over the area, with cooler temperatures for the beginning to the middle of the week. Also, the High Risk of Rip Currents will be allowed to expire this evening, as the wind is forecast to become more southerly overnight, and persist out of the south most of tomorrow. This would likely induce more of a longshore current, which would help to lessen the risk of rip currents. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 73 81 61 74 / 40 60 40 10 Fort Lauderdale 73 82 65 76 / 50 50 50 10 Miami 74 81 66 75 / 50 40 40 10 Naples 72 76 64 75 / 70 50 10 0 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk until 7 PM EST this evening for FLZ168-172- 173. AM...None. GM...None. && UPDATE...13 AVIATION...88/ALM
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
609 PM CST Fri Dec 14 2018 .UPDATE... Issued at 545 PM CST Fri Dec 14 2018 Updated to include 00z aviation discussion below. && .SHORT TERM...(This evening through Saturday night) Issued at 253 PM CST Fri Dec 14 2018 After days of fog and stratus, today`s sunny skies are very much a welcomed change. Where the snowpack is thin across western MN, we have seen many sites top out in the 40s. This nice weather is the result of the continued split flow, with us in between the northern stream up across central Canada and the southern stream closed low over the southeast. Biggest change in this forecast was to significantly pull back on the fog mention for tonight. The HRRR has done a good job on a nightly basis with depicting the general evolution of the fog/stratus and it has been consistent today in showing pretty much no fog within the MPX area tonight. The near surface moisture layer will be even shallower tonight than it was last night, which supports a lack of fog. In addition, we saw the fog last night dissipate during the overnight hours, indicating the atmosphere that we have had come in is not very supportive of fog. The surface ridge axis tonight will be spread out from southeast Neb, southeast MN to the WI/MI border, so the greatest threat for seeing fog tonight will be near this feature across southeast MN and central WI. In all likelihood, there will be some freezing fog in this region, but no where near the extent we have seen the last few days. For Saturday, it will be another beautiful sunny day. Given the fact that temepratures today are running at the top end of the model spread envelope, bumped up highs for Saturday toward the high end of the guidance envelope, with mid 40s expected out in west central MN, with the Twin Cities again taking a run at 40. Saturday night, the wave that is coming ashore in the Pac NW this afternoon will be coming across the upper MS Valley. This will send another surface trough across the area, but it will be completely moisture starved, so will do no more than lead to an increase in high clouds, though the combination of cloud cover and winds remaining through the night will result in milder lows (teens unlikely) and a minimal threat for fog Saturday night. .LONG TERM...(Sunday through Friday) Issued at 253 PM CST Fri Dec 14 2018 Overall, a benign forecast with the next chance for precipitation not coming until the middle of next week. By Sunday, the cold front will have moved through the forecast area with 10-15 MPH northwest winds likely through the day. The air mass behind the front will be quite mild, so the front is moreso a simple wind shift. With ample dry air behind the front, sunny skies should prevail and temperatures should have no trouble reaching the mid 30s without any cold air to our northwest. Monday will be cooler with the ridge axis moving through the area. The sunny skies will continue with no weather systems near the area. Tuesday and Wednesday look mild with southerly flow developing as the surface ridge slides to our east. Would not be surprised to see readings reach 40 degrees on either day. Meanwhile, the next system to watch will be a shortwave emerging from southern Alberta, racing east-southeast and reaching Minnesota Wednesday night. This clipper could provide a quick shot of snow to the area, but at this time most of the deep moisture and lift looks to hit northern MN more directly. Once the front associate with the clipper goes through, strong northwesterly winds will develop. Could see the potential for 30+ MPH gusts for next Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 545 PM CST Fri Dec 14 2018 More of an optimistic forecast for the overnight hours in this TAF set than in previous nights due to shallower moisture and the center of high pressure shifting from northern IA into central WI. Overnight fog looks to be restricted to far eastern MN through western WI, thus making KRNH-KEAU most susceptible but leaving the possibility open for KMSP. Otherwise, little to no clouds will be the story through the next 24 hours. An approaching low level jet streak in advance of an approaching dry cold front for Sunday will enhance winds in the 1-2 kft level tomorrow afternoon to tomorrow evening. Have shown this thus far in western MN with LLWS mention, with it likely translating to eastern MN and western WI after 00z tomorrow evening. KMSP...Fog chances are much lower than in previous evenings but cannot be ruled out altogether, especially given that IFR readings were prevalent with SE winds 2 mornings ago and SW winds this past morning. However, shallower moisture looks to make fog less likely at MSP. Plus, MSP is commonly the last terminal to deal with fog, even while the metro satellite airports report it. At this point, will show the uncertainty with a TEMPO MVFR mention and adjust as needed. /OUTLOOK FOR KMSP/ Sun...VFR. Winds NW 10G20 kts. Mon...VFR. Winds light and variable. Tue...VFR. Wind SW 10G20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ UPDATE...JPC SHORT TERM...MPG LONG TERM...SPD AVIATION...JPC
Area Forecast Discussion
National Weather Service Topeka KS
506 PM CST Fri Dec 14 2018 ...AVIATION UPDATE... .SHORT TERM...(This evening through Saturday) Issued at 227 PM CST Fri Dec 14 2018 The upper low and associated trough continue to slowly move east away from the region while weak high pressure at the surface has moved into the region from the higher terrain of NE/CO/WY. Drying/subsidence near the ridge axis is helping to lower dewpoints into the upper teens and lower 20s across the area which could have implications on lows tonight. Given clear skies and winds which should become calm after midnight expect strong radiational cooling with lows expected to drop toward current dewpoints. Cannot rule out patchy fog but lack of recent rain and a full day of drying sun should help keep areal coverage of any fog limited to local effects/near rivers tonight. The sfc ridge will move over the area on Saturday with sunny skies and light winds which should help air temps reach into the 50s so a great day appears in store for Sat. .LONG TERM...(Saturday night through Friday) Issued at 227 PM CST Fri Dec 14 2018 The overall weather pattern is forecast to remain mild and mainly dry through next week. A weak system is forecast to move through the region Tues into Weds with only low precip chcs and that should be mainly rain given how warm temps will be. Aside from that system no other storms appear on the horizon as we head toward the end of next week with warmer than avg conds forecast to persist into late week. && .AVIATION...(For the 00Z TAFS through 00Z Sunday) Issued at 506 PM CST Fri Dec 14 2018 Dewpoint temps mixing out into the teens late this afternoon raises some considerable doubts about radiational fog overnight. And the latest RAP forecast soundings struggle to saturate the boundary layer with any moisture remaining very shallow. Therefore will remove the mention of fog as even the objective MOS guidance fails to generate any fog. The dry air with the surface ridge should lead to VFR conditions prevailing. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Omitt LONG TERM...Omitt AVIATION...Wolters