Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/24/17


Area Forecast Discussion
National Weather Service Wakefield VA
949 PM EDT Mon Oct 23 2017 .SYNOPSIS... A weakening cold front slowly push through the local area late tonight into early Tuesday. A second cold front crosses the area Tuesday night. High pressure builds across the Gulf of Mexico Wednesday and Thursday...as low pressure lingers from the Great Lakes to New England. && .NEAR TERM /THROUGH TUESDAY/... Current analysis indicates sfc high pressure well off the coast, with low pressure deepening to the lee of the central Appalachians (this out ahead of parent sfc low over MI). Areas of showers are overspreading much of the western Piedmont this evening. Earlier stronger line segments in vicinity of the Blue Ridge in NC and VA have weakened, with the stronger activity now in central NC. Little overall change in thinking with the scenario tonight, with a high shear/low CAPE event expected, which has prompted a Tornado Watch that extends into the Ern VA Piedmont and runs through 06z. The best lift/forcing for likely to categorical PoPs (60-90%) looks to reach to areas west of I-95 through midnight, then pushing E to the I-95 corridor from 03-06Z, and to the coast from 06-12Z. Strong low level jet and effective shear values to 50-60 KT (and some directional shear through 06Z as SSE sfc winds interact with SSW winds in the H85 to H7 layer. The last few runs of the HRRR depict the potential for some stronger convection to push into S-central VA prior to 06z, with a weakening trend thereafter. SPC has SLGT risk SVR for SW parts of the local area (shifting to the ern shore Tue morning). If it all comes together, an isolated severe tstm with damaging winds and even an isolated tornado can`t be ruled out. However, more likely it will be just a narrow line of showers with embedded convection with wind gusts staying below severe limits (to 40-45 mph). Will continue the mention of locally heavy rain and strong/gusty winds in the HWO. Expect skies to turn partly to mostly sunny by late morning W and by late aftn E...and have continued w/ lowering PoP trend W-E. Still rather warm as winds remain from the SW, with highs Tues in the mid 70s W to the lower 80s SE as cold air lags well behind off to the NW of the local area. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... Latest 12Z/23 GFS/NAM/ECMWF remain in good agreement Tue night into Wed, but then show some fairly significant differences with respect to the strength of the upper low over the eastern CONUS by late Wed/Thu. The ECMWF the deepest/farthest south and the GFS the weakest/most progressive and the NAM somewhere in between but genly a little more like the ECMWF. Will side a little more to the NAM/ECMWF consensus, but not quite to the extent of how deep the upper low digs south. Thus, the sfc cold front reaches the coast early Tue night and is expected to exit the coast by daybreak Wed morning. Any RA tapers/ends at the coast Tue evening. Lows will range from the upper 40s west of I-95 to the mid/upper 50s closer to the coast by Wed morning. Dewpoints also fall from the lower 50s NW to lower 60s SE in the evening to 40-45F inland and 45F to around 50F by morning. On Wed...local area looks to remain in between the sfc cold front well offshore and deeper moisture/cold pool aloft to our WNW. Some SCT/BKN cu will tend to linger due to some shortwave energy aloft, but should be dry with highs mainly in the m-u60s (staying a little below MAV numbers as they are based off the warmer GFS). For Wed night/Thu, siding to the NAM/ECMWF allows for some digging SE of the upper level shortwave energy from the Great Lakes through the Carolinas by thu morning. Will keep it dry for now, with partly cloudy conditions. Lows Wed night mainly in the 40s and highs Thu 60-65 F under partly to mostly sunny skies. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Long term period starts off dry Thu night/Fri with sfc high pressure over the immediate area and W/SW flow aloft. With light sfc winds under a clear sky, expect low temps Thu night in the low/mid 40s most of the area, and highs in the mid/upr 60s Fri. Attention then turns to an approaching deep upper-level trough Sat. Although any pcpn will likely hold off until after daytime Sat, included a 20% chance of a shower in case the faster ensemble member solutions pan out. Better chance of rain (40-50%) arrives Sat night/Sun as strong sfc low pressure forms out ahead of the upper-level trough. There is still plenty of uncertainty over the track of this low, but the possibility is there for moderate to heavy rain Sun. High temps in the mid/upper 60s Sat drop to the upr 50s to mid 60s Sun. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Low pressure and an associated cold front will approach fm the west this evening, then the actual cold front will gradually cross the region and move offshore later tonight into Tue evening. Increasing SE then S winds expected this evening thru Tue morning ahead of the front, with showers and possible tstms moving thru the CWA later this evening into Tue morning. SE or S winds 10-15 kt, with gusts up to 25 kt possible during this time period, with higher gusts possible in stronger showers or tstms. This front will bring the potential for MVFR/IFR conditions in showers and lower CIGS. Mainly VFR conditions expected later Tue aftn/evening through Fri. && .MARINE... Previous marine headlines remain in place ahead of an approaching cold front. Decided to put all headlines in effect with this package with SCA conditions expected to commence over all wtrs within 12 hr. The SCA is for 15-20 kt southerly winds over the rivers/Sound and 15- 25 kt winds with gusts up to 30 kt over the Bay and ocean. Waves up to 4 ft over the Bay with seas over the ocean up to 7-8 ft. A trough of low pressure ahead of the cold front slides through the area early Tue, with the pressure gradient relaxing a bit into the day Tue and winds decreasing to below SCA thresholds. Main cold front crosses the area Tue night with sub-SCA NW winds expected behind the front into Wed. Will maintain the SCA over the ocean through the day Wed due to a prolonged period of 5 ft seas. Lighter winds and sub- SCA conditions into Thu and Fri with sfc high pressure over the area. && .TIDES/COASTAL FLOODING... A modestly strong SSE wind ahead of a cold front will potentially push tidal anomalies to 1.0-1.5ft above normal late tonight into early Tuesday morning. This could push some locations near minor flooding thresholds (mainly Cambridge and Bishops Head) during high tide late tonight into early Tuesday morning. Water levels at these locations potentially remain elevated for the following high tide (aftn/early evening), which is the higher astronomical tide. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 10 AM EDT Tuesday for ANZ635>638. Small Craft Advisory until 4 PM EDT Tuesday for ANZ630>632-634. Small Craft Advisory until 7 PM EDT Tuesday for ANZ633. Small Craft Advisory until 7 PM EDT Wednesday for ANZ650-652- 654-656-658. && $$ SYNOPSIS...LKB NEAR TERM...LKB SHORT TERM...ALB/LKB LONG TERM...MAS AVIATION...LKB/TMG MARINE...AJB/MAS TIDES/COASTAL FLOODING...AJZ
Area Forecast Discussion
National Weather Service State College PA
1139 PM EDT Mon Oct 23 2017 .SYNOPSIS... A strong frontal system will push colder air into the region tonight into Tuesday. A second shot of cold air is expected this weekend. Overall most of the coming 6-8 days the region will be in a mean trough thus cooler weather will be the norm for awhile. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Regional radar at 02Z showing band of rain lifting into the Laurel Highlands/Northwest Mtns along axis of anomalous southerly low level jet/PWATs preceding potent shortwave lifting into the Grt Lks. Mesoscale guidance continues to indicate most of the rain will come with this north-south band during the late evening hours over the western half of the forecast area and during early Tuesday morning across the eastern half of the forecast area. Latest guidance indicates increasing low level instability late tonight ahead of vort max lifting north from Virginia in conjunction with 850 winds in the 60-70kt range. Thus, expect an increasing threat of severe weather over eastern Pa late tonight. Per collaboration with neighboring offices, have covered much of the region with a wind advisory late tonight. Bufkit soundings support gradient wind gusts in the 20-30kt range, but any strong convective cores could easily bring 50+ mph winds to the surface. The v-winds are about 4 to 5 sigma above normal ahead and along the frontal boundary. Most areas will have a good 2-4 hour window of rain, with ensemble mean QPF ranging between 0.5 and 1 inch. In the HRRR and the GEFS this has a classic NCFRB look so most of the rain will be close to the frontal boundary. Rapidly improving indicated across the western half of the forecast area late tonight behind the line with partial clearing. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... Cold front and associated gusty showers/storms should exit the eastern portion of the forecast area between 12Z-15Z. Model soundings support a good deal of morning sunshine in region of large scale subsidence behind front. However, diurnal heating combined with approach of upper trough axis and secondary cold front should result in increasing cumulus by afternoon with even a PM sprinkle possible across the Alleghenies and central mountains. The coldest air does not filter in until Wednesday but Tuesday will be the start of a cooler period. Enjoy what could be one of the warmest days for some time to come. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... Surface ridging indicated over central Pa by med range guidance late Tuesday through Friday, indicating dry weather for most of the forecast area. The exception will be late Wed, when passage of shortwave could produce a few showers across the northwest mountains. Ensemble mean 925/850 temps are slightly below normal Wed/Thu, likely translating to max temps from the upper 40s over the Alleghenies, to the upper 50s across the southeast counties. This cooler stretch will be short lived as heights and 850 temps rise quickly into next weekend. Another chance for precipitation will arrive at the end of the period when a cold front is anticipated next Sunday, bringing rain to much of the CWA, while colder air and a few waves of low pressure riding NNW along the front brings the chance of a light to moderate, and elevation dependent snow event. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... Rain consolidating into a gusty line...with the leading edge from near KBFD to KAOO to KHGR. Significant winds with low level jet continues to strengthen...with surface wind gusts approaching 40 kts in some locations. Line will continue to pivot east, and is expected to intensify as instability increases. With 850 mb winds forecast to be in the 50 to 70 knot range overnight, expect surface winds to regularly gust between 20 and 30 kt...and between 40 and 50 kts in the vicinity of the CFROPA. Could also see some isolated thunder in convection especially over eastern areas. These strong wind fields also introduce high potential for LLWS pre and during FROPA. Showers and rain will end rather abruptly from west to east overnight. With the FROPA, also should see a quick drop in strong wind gusts. Windshift behind the front will be somewhat subtle...shifting from the SSE to the SSW. Most notable again will likely be the noticeable drop off of strongest wind gusts behind the front. Ceilings will mainly be in the MVFR range overnight, but a narrower corridor of IFR ceilings expected to accompany the front. Visibilities may be restricted in areas of heavier rain, but should mainly remain in the VFR/MVFR range. Tuesday will be breezy behind the cold front, with improving conditions as the front swings east. Showers may linger till around 12z in the east. More scattered showers will develop in the mountains in the afternoon. Conditions generally back to VFR across Central Pennsylvania after about 14-16Z. Outlook... Wed-Thu...Mainly VFR, but scattered showers and ceiling restrictions in the western and northern mountains. Fri...Mainly VFR. Fri Night-Sat...Another approaching cold front with chance of showers. && .CLIMATE... Through 10/22/17, the average monthly temperatures at Harrisburg and Williamsport are 63.8F and 61.8F. When compared to the maximum 1-month mean avg. temperature for previous Octobers, both would rank as the warmest on record. Computing a daily avg. temperature when only taking into account the first 22 days of the month and comparing to the previous Octobers, the rankings are #2 at IPT and #3 at MDT. && .CTP WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 8 AM EDT Tuesday for PAZ028-036-037-041- 042-046-049>053-056>059-063>066. Wind Advisory until 4 AM EDT Tuesday for PAZ004>006-010>012- 017>019-026-027-035-045. && $$ SYNOPSIS...Fitzgerald/Lambert NEAR TERM...Fitzgerald SHORT TERM...Grumm/Fitzgerald LONG TERM...Lambert/Gartner AVIATION...Jung CLIMATE...
Area Forecast Discussion
National Weather Service Grand Rapids MI
1003 PM EDT Mon Oct 23 2017 LATEST UPDATE... Update .SYNOPSIS... Issued at 328 PM EDT Mon Oct 23 2017 Low pressure moving north across Lower Michigan will continue to bring heavy rain with some flooding expected through Tuesday. The low will deepen on Tuesday and winds will be ramping up with some strong wind gusts Tuesday and Tuesday night. && .UPDATE... Issued at 957 PM EDT Mon Oct 23 2017 With the potential for Gales less than 12 hrs away we upgraded the watch to a warning. No other changes were made to the forecast. Satellite imagery shows the coldest cloud tops pivoting north of the region. Radar and rain gage trends show the precipitation is weakening in intensity. There is still a lot of forcing around and a very moist airmass in place. Thus it appears mostly light rain with periods of moderate rain can be expected right into Tuesday. && .SHORT TERM...(This evening through Wednesday night) Issued at 328 PM EDT Mon Oct 23 2017 Heavy rain tonight into Tuesday and high winds Tuesday into Tuesday night are the main forecast issues in the near term. The Flood Watch was replaced with areal Flood Warning across the western third of the forecast area and an areal Flood Advisory to its east. The southeast zones are not expected to see flooding and the watch was dropped there. Surface low was centered just south of AZO at 330 PM and is moving north with strong area of f-gen expected to continue producing inch an hour rain rates across the warning area through the evening. We have been fortunate that the bulk of the heaviest rain has remained over Lake Michigan so far today, but amounts over 2 inches have occurred across parts of Ottawa, Muskegon, Oceana Counties with a report of nearly 2.25 inches near Holland at 320 PM. The heavier rain is moving onshore and the HRRR has the f-gen area pivoting across our northwest zones tonight. So 3 to 5 inches of rain is possible in the warning area with amounts of an inch or less across the southeast zones by Tuesday afternoon. The other issue we will have to deal with high winds on Tuesday as the low rapidly deepens across northern Lower Michigan. Tightening pressure gradient and strong cold advection will combine to bring gusts to wind advisory criteria during the morning across the northern coastal zones and by afternoon across central and southern zones. We have issued a wind advisory for this area. The winds will subside after midnight as the low pulls away. .LONG TERM...(Thursday through Monday) Issued at 328 PM EDT Mon Oct 23 2017 Main weather highlights in the long term period are a period of milder and quieter weather Thursday into Friday, followed by more cold air for the weekend through Halloween. Quiet weather day expected for Thursday due to shortwave ridging in between the exiting upper trough and the next one dropping into the north central U.S.. Also milder temperatures expected on Thursday with high temps 55 to 60 as warm advection strengthens in advance of next approaching system. Friday may also be a mild day if the slower ECMWF timing of the next cold front is correct. Deep longwave trough is progged to impact the Great Lakes Region next weekend, resulting in scattered showers with highs only in the mid 40s. Some snow showers will be possible at night and in the early morning when temperatures cool, especially inland from Lake MI and in higher elevation areas. Any clearing at night could lead to sub freezing temperatures. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 748 PM EDT Mon Oct 23 2017 With the storm system remaining in the region through Tuesday...impacts will continue at the TAF sites. IFR/MVFR conditions will prevail with local VFR possible. As the colder air wraps in behind the storm for Tuesday lake effect moisture will keep the ceilings and visibilities low through the day. Gusts over 25 knots will be possible...especially on Tuesday for KMKG. && .MARINE... Issued at 328 PM EDT Mon Oct 23 2017 No significant changes to the previous forecast. Winds and waves will be increasing tonight and gales are still expected to develop on Tuesday. Northwest gales will probably begin during the morning across areas north of Whitehall and during the afternoon south of there. && .HYDROLOGY... Issued at 1211 PM EDT Mon Oct 23 2017 River levels are rising across the area. Rainfall of up to two inches has fallen through this morning and another two to three inches are possible through Tuesday. More rain is also possible through the week. Warnings have been issued for Croton on the Muskegon River, Rockford on the Rogue River, and Vicksburg on the Portage River. More river warnings could be issued depending on the amount of rain that falls and where it falls. Areal flood warnings and watches are also in effect though Tuesday. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Wind Advisory from 2 PM Tuesday to 3 AM EDT Wednesday for MIZ050- 056-064. Wind Advisory from 8 AM Tuesday to 3 AM EDT Wednesday for MIZ037- 043. LM...Small Craft Advisory until 10 AM EDT Tuesday for LMZ844>849. Gale Warning from 10 AM Tuesday to 8 AM EDT Wednesday for LMZ844>849. && $$ UPDATE...MJS SYNOPSIS...Ostuno SHORT TERM...Ostuno LONG TERM...Meade AVIATION...MJS HYDROLOGY...63 MARINE...Ostuno
Area Forecast Discussion
National Weather Service Houston/Galveston TX
953 PM CDT Mon Oct 23 2017 .UPDATE... A cool overnight with temperatures bottoming out in the interior lower 50s...coastal lower 60s. A secondary cold front to come through and provide a shot of colder...drier air to the region tomorrow. Strong northerlies in the wake of the front may reach Wind Advisory criteria along the immediate coastline tomorrow morning into the early afternoon. Middle 30 to lower 40 degree dew points...with mid to upper 70 afternoon warmth...will increase fire weather concerns as daytime relative humidities plummet into the low to mid 20 percentile through Wednesday. Offshore winds weaken and return onshore Thursday. The next cold frontal passage slated for Friday will not have much moisture to work with so late week rain chances will be low. 31 && .PREV DISCUSSION... /ISSUED 624 PM CDT Mon Oct 23 2017/ AVIATION... A reinforcing cold front will be moving through the area later tonight. Look for winds to increase and become quite gusty during the day Tuesday. Otherwise...VFR conditions will prevail. 47 && PREV DISCUSSION... /ISSUED 348 PM CDT Mon Oct 23 2017/ Mainly a wind and temperature forecast for this afternoon`s update. Starting at 06Z, short term guidance such as the HRRR and RAP13, bring a wind shift into the northern zones of the forecast area, shifting the winds out of the north/northeast. The coast should see this wind shift by 10Z. The pressure gradient tightens during this time frame, and as a result winds will pick up to 5 to 9 mph over land between 06 to 12Z. A secondary cold front following the front that passed yesterday, will act to provide an additional reinforcement of cooler air. Low temps this evening are still expected to range in the 50s to low 60s along the coast, while the effects of this secondary cold front will not truly be felt until Tuesday. Model guidance has also trended cooler Tuesday and Tuesday night, with radiational cooling anticipated with these clear night skies, and therefore decided to lower temps by a few degrees. As the surface high shifts southeast, Monday night into Tuesday, this tighter pressure gradient should cause an increase in wind speeds throughout the afternoon Tuesday, keeping winds between 10-15 mph over land, with gusts to around 20 mph. Additionally, as cooler air continues to advect in the region Tuesday, high temperatures will struggle to make it out of the mid 70s. Tuesday will also be the driest day this week, with min RHs between 20 to 25%. With these RH values and stronger winds over the area, elevated fire weather conditions will be of concern. Tuesday night into Wednesday will be the coolest night before the weekend, with low temperatures plummeting into the low 40s near Bryan/College Station to upper 50s along the coast near Galveston. Highs again Wednesday will struggle to make it into the mid 70s. The pressure gradient slackens Tuesday into Wednesday, and a stronger region of high pressure scoots in from the northeast. Therefore, fire weather conditions will be less of a threat Wednesday. Onshore winds will return late Thursday as the area of high pressure weakens. This will help to increase moisture over the region Thursday afternoon, and by Friday PWs will range between 0.7 to 1.0 inches. Timing of the frontal passage late in the week amongst the various global models is still inconsistent. GFS is still a little faster than the ECWMF, though the solutions of both have come closer together in time. Progression of the front through SE TX looks to occur late Friday afternoon into Saturday morning. Sunny skies will become partly cloudy as a result of the front Friday afternoon. The ECMWF also brings in a bit more precipitation out ahead of the front than the GFS, late Friday into Saturday. In terms of intensity, the ECMWF is providing the coolest solution in comparison to the GFS and NAM. Remaining conservative in the forecast for now, though leaning towards the ECMWF solution. Saturday into Sunday, 850 temperatures range between 2 to 5 degree Celsius, which is a touch on the colder side for this time of year. Confidence remains low on just how strong this front will be. Therefore, temperatures could trend cooler this weekend as the models get a better handle on the airmass in the next few days. 08 && MARINE... Winds over the waters are relatively light this afternoon and will continue so into the evening as high pressure moves east of the area. Winds should pick up overnight as a front moves through, and are expected to reach advisory levels over the Gulf by morning. The advisory begins a few hours before the threshold is forecast to be met to cover the period of SCEC-level wind. The advisory carries through Wednesday morning - the 0-20 nm zones may see a bit of a lull in the afternoon, but with the expectation that winds will exceed the advisory threshold again tomorrow night, chose to keep one longer advisory. Look for winds to diminish Wednesday as another high pressure center moves across the region. As that high moves off to the east, onshore flow should return on Thursday. The next front is expected to arrive Friday, and looks strong enough to bring another period of strong, gusty winds. 25 && FIRE WEATHER... Dry air will be reinforced by another cold front overnight. Unlike today, winds behind the front will be considerably stronger. As a result, we`ll be looking at an RH and wind combo that is near the threshold for a red flag warning. Min RHs look to be in the neighborhood of 25 percent (a touch lower farther inland, a smidge higher at the coast), with winds also in the 15 mph ballpark and gusts to around 20 mph. In addition to that, overnight recovery looks decent, but not outstanding tonight, and even worse Tuesday night. But, with all that said, we are fortunate to have generally wetter than normal fuels. Outside of the 10 hour fuels, which are more receptive to changes in RH, rain from Sunday morning will help mitigate conditions. Because of that, will decide against going with any fire weather headlines. However, those with more grassy fuels should be aware of the dry air and winds expected, and understand that fire may spread more rapidly than they might expect given the recent rain. Low humidity will persist deep into the week, until the return of onshore winds on Thursday will begin to return moisture back to Southeast Texas. Fortunately, high pressure drifting across the area will keep winds lighter than we`ll see tomorrow. This will mitigate fire weather concerns to some extent for Wednesday and Thursday. 25 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 52 78 43 76 46 / 0 0 0 0 0 Houston (IAH) 53 76 48 76 49 / 0 0 0 0 0 Galveston (GLS) 61 76 58 73 62 / 0 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...Small Craft Advisory from 4 AM to 4 PM CDT Tuesday for the following zones: Galveston Bay...Matagorda Bay. Small Craft Advisory from 4 AM Tuesday to 3 AM CDT Wednesday for the following zones: Coastal waters from Freeport to the Matagorda Ship Channel out 20 NM...Coastal waters from High Island to Freeport out 20 NM...Waters from Freeport to the Matagorda Ship Channel from 20 to 60 NM...Waters from High Island to Freeport from 20 to 60 NM. && $$ Discussion...31/47
Area Forecast Discussion
National Weather Service Wilmington NC
849 PM EDT Mon Oct 23 2017 .SYNOPSIS... A strong cold front will approach from the west today and slow, finally moving completely offshore Tuesday afternoon. Showers and thunderstorms are expected along and ahead of the front with the possibility for a line of strong to severe thunderstorms this evening and tonight. In the wake of the front, dry and cool air is expected through Thursday as Canadian high pressure takes hold. A warming trend begins Friday. Shower chances increase Saturday as a weak area of low pressure develops ahead of a second cold front. && .NEAR TERM /THROUGH TUESDAY/... As of 830 PM Monday...Axis of surface-based instability was moving eastward across the Pee Dee region as of 00Z, with LI`s of -2C to -3C extending from near LBT southward through Kingstree. Modest surface pressure falls were occurring just east of this axis of instability, and will transition eastward and off the coast over the next few hours. Although backing of the surface winds in response to these pressure falls has been modest across the CWA, the shear profiles as evidenced by KLTX VWP will remain conducive for storm rotation through the remainder of the evening. Latest HRRR indicates the thunderstorm activity will move off the coast around 06-07Z. Cool advection lags considerably behind the wind-shift though dewpoints may start dropping Tuesday afternoon temperatures will still warm up into the upper 70s, a solid category above climatology. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 300 PM Monday...Very quiet conditions will settle into the area as a deep full latitude mid level trough moves from the Tennessee Valley to just offshore through the period. Precipitable waters dip to near one quarter of an inch by late in the period. At the surface a somewhat blustery pressure gradient will reside across the area and this is reflected n the guidance. There may be some decoupling early Thursday morning allowing temperatures to possibly drop to the coolest readings of the season in some areas with lower to mid 40s area wide. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 300 PM Monday...Very cool temperatures start the extended as Canadian high pressure settles across the area before pushing offshore Friday. Temps Thursday will likely be about 5 degrees below climo before recovering to more seasonable temps Friday as the surface high shifts offshore. Moisture will begin to increase Saturday on increasing southerly winds as a pre-frontal airmass returns ahead of a deep mid-level trough pushing through the MS VLY. This will drive a cold front across the area Saturday night into Sunday. Ahead of this feature, a weak area of low pressure may develop and move just off the coast, and while total column moisture remains confined below 700mb, showers are possible late Saturday through Sunday morning associated with this feature. This front will bring the potential for the coldest air of the season behind it, as 850mb progs drop below 0C and extended MOS numbers feature values as much as 10 degrees below climo early next week. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 23Z...Latest radar showing precipitation moving up the SC coast soon to impact KMYR and KCRE. Light rain already at KFLO and KLBT with nothing yet at KILM. Forecast for the overnight period still a bit tricky with VAD wind profile showing some veering between 8k and 17k with 35 to 45 kt winds. As front pushes to the east storm motion is moving all cells to the NE at greater than 30 mph. Impacts will affect all terminals through the evening/overnight period with high confidence in MVFR and possible IFR conditions in vsby and ceiling. Have mentioned tstm across the inland terminals but not to confident at the coastal terminals although cannot totally ruled out but will not mention at terminals. Gusty SSE to S winds will prevail overnight until FROPA and will mention low ceilings and vsby across KLBT and KFLO with fog as winds abate behind the front. Weather will improve from west to east across the terminals. Concern might be for some wind shear around 03z near the coast but will keep an eye on this as VAD winds are pretty uniform with the wind speeds from the sfc up to about 4-5K. main concern for all terminals will be between 00Z and 06Z before condition slowly improve. After 25/15z VFR conditions across the region. Extended Outlook... VFR Wednesday through Friday. Slight chance for showers Saturday. && .MARINE... NEAR TERM /THROUGH TUESDAY/... As of 830 PM Monday...Latest buoy obs are indicating strong southerly winds across the waters, with gusts of 25-30 knots. Seas at buoy 41013 were running near 8 feet. Latest guidance suggests winds will diminish late tonight across the SC waters, and early Tuesday morning north of Cape Fear. Seas will subside below SCA thresholds beginning early Tuesday south of Little River Inlet, and by early afternoon across the waters north of Little River Inlet in the wake of the wind shift. Won`t make changes to the SCA at this time, but if this timing expectation holds, we may be able to remove the southern waters from the SCA a little earlier on Tuesday than 18Z. SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 300 PM Monday...Northwest winds of 10-15 knots and on occasion 15-20 knots will prevail across the area through the period. The persistence will be provided by a very deep and slow mid level trough at 500mb that trudges across the conus from the Mississippi Valley. Significant seas will be mostly 2-4 feet with the higher values across the outer waters with the offshore flow. LONG TERM /THURSDAY THROUGH SATURDAY/... As of 300 PM Monday...High pressure moving overhead the waters Thursday into Friday will create gusty north winds early Thursday before weakening to less than 10 kts and shifting slowly to NE Friday, and then E on Saturday. A secondary front approaching very late Saturday may cause winds to uptick again at the end of the period. The gusty north winds early will keep seas elevated at 3-4 ft the first half of Thursday, before falling back to 1-3 ft Fri and Sat. The increased winds late Saturday may cause seas to begin to rise again at that time. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...Small Craft Advisory until 2 PM EDT Tuesday for AMZ250-252-254- 256. && $$ SYNOPSIS...JDW NEAR TERM...CRM SHORT TERM...SHK LONG TERM...JDW AVIATION...MAC