Marine Weather and Tides
1/26/2021 -- The West Coast Satellite images havd been updated. They now use GEOS-17.
1/1/2021 -- The 7 day forecast are now working well. Thank you NOAA for your support.
|Sunrise 6:53AM||Sunset 6:30PM||Thursday March 4, 2021 11:50 PM EST (04:50 UTC)||Moonrise 12:00AM||Moonset 10:25AM||Illumination 60%|
7 Day Forecast for Marine Location Near Lowndesville, SCHourly EDIT Help
Area Discussion for - Greenville-Spartanburg, SC  (on/off)  Help NOTE: mouseover dotted underlined text for definition
FXUS62 KGSP 050258 AFDGSP
Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 958 PM EST Thu Mar 4 2021
SYNOPSIS. Dry high pressure will set up through our area through Friday before a Gulf Coast low pressure system passes mostly south of the region Friday night into Saturday, with minimal chance for rainfall. Canadian high pressure builds back into the area Sunday, maintaining warm, dry conditions through the middle of next week.
NEAR TERM /THROUGH FRIDAY/. As of 940 PM: Region remains under northwesterly flow aloft with dry northerly to northwesterly surface winds. A very weak cold front will settle thru the area in the next few hrs, with the only real effect being dewpoints trending still lower behind it. No groundbreaking changes with this update; the usual tricky task of accounting for decoupling/radiation, with the added prospect of the overnight CAA. So far what light winds persist have been effective at keeping us warmer that most of the guidance at this hour, but a more rapid decline is expected once the front settles past. All things considered, and particularly expecting a little bit of a breeze to persist in more of the area than last night, mins now look to end up within a couple degrees of normal.
Winds decline on Friday as Canadian/Midwest surface high builds in our direction. Reduced downslope and continued cool advection will reduce maximum temperatures and depth of mixing on Friday, with reduced high temperatures and less gusty conditions, though winds will remain from the NNW. Highs Friday look to be 10 degrees lower than Thursday's. Late on Friday, clouds aloft will be increase in advance of the next synoptic system that will be advancing past the Lower Mississippi Valley.
Main near-term impact will be in the fire weather arena again on Friday; actually lowered dewpoints a bit further with this update, and min RH now drops below 20% in many areas. See the fire weather discussion at the end of this product for more details.
SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/. As of 1255 PM Thursday . Our relatively dry weather should continue through the balance of the weekend as deep mid/upper trof remains in place along the East Coast, maintaining a NW flow aloft. Model guidance continues to show a short wave dropping down into the base of the trof late Friday night/early Saturday morning, but all indications are this feature will be somewhat moisture-starved. The GFS continues to develop some light precip Saturday morning over northeast GA, possibly in response to some low level convergence, but this still appears to be overdone. A dry fcst was inherited and the new fcst will remain dry. About the only effect will be an increase in cloudiness early Saturday, which has bumped up min temps a degree or two. The clouds move out by midday, followed by a reinforcing sfc high building in from the north through the rest of the period. Temps will generally remain 3-5 degrees on the cool side of normal owing to the upper pattern. The main lingering problem will be fire weather. See below.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/. As of 130 PM EST Thursday . still looking like an inactive pattern for the extended. By Sunday night, any forcing associated with the upper trough crossing New England will have shifted well out of our area, with attendant high pressure already building in at the surface. Throughout the day Monday, continuing north-northwesterly flow will induce weak CAA, which looks to be somewhat offset by downsloping flow off the Appalachians. This will have the added effect of keeping dry conditions through the day on Monday and raising another potential day of fire weather concerns.
Monday night or early Tuesday morning, winds will shift to southwesterly as the high pressure center passes to our east, and we'll enter a WAA regime. As Gulf moisture finally begins advecting into the region, RHs will slowly creep upward through the rest of the week, averting any continued fire weather threat. Nonetheless, skies should stay clear through Thursday and good insolation should push afternoon temps into the mid/upper 60s each day. By Thursday night, a cold front will be positioned to our north over the Ohio Valley, but looks to be stalling too far north to warrant any more than chance PoPs. For now, simply a feature to keep an eye on as models come into better agreement on what will happen.
AVIATION /03Z FRIDAY THROUGH TUESDAY/. At KCLT and elsewhere: VFR, with the only aviation concern being winds. Breezy conditions are ongoing in many parts of the area at issuance time with sustained winds 7-12 kt and in some cases gusts to over 20 kt. CAA will strengthen this evening in the low levels behind a weak cold front, but SKC will promote decoupling. The question is how long it takes for that to occur in light of the CAA. Thinking this should occur within the first few hrs of the TAF. Beyond that, winds will be fairly light, veering mostly to NE during the day Friday. KAVL is as usual an exception, holding onto gusts longer and staying NW-NNW thru the period. Cirrus will filter in ahead of a shortwave by Fri afternoon.
Outlook: A Gulf Coast low pressure system will likely pass south of the terminal area Friday night into Saturday, possibly bringing a few restrictions. Dry high pressure returns again for the remainder of the weekend into early next week, and VFR likely will prevail during that time.
Confidence Table .
03-09Z 09-15Z 15-21Z 21-00Z KCLT High 100% High 100% High 100% High 100% KGSP High 100% High 100% High 100% High 100% KAVL High 100% High 100% High 100% High 100% KHKY High 100% High 100% High 100% High 100% KGMU High 100% High 100% High 100% High 100% KAND High 100% 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 are available at the following link:
FIRE WEATHER. The airmass that will build into the area thru Friday is exceptionally dry, and RH will bottom out below 20% in many areas again Friday, and perhaps below 15% where downsloping also occurs. This trend is expected despite temps being somewhat cooler than Thursday's. Winds will be lighter, but fuels steadily drier, and we may need to consider another Fire Danger Statement at least for parts of NE GA. A weak upper system will cross the region early Saturday morning. A few sprinkles are possible over northeast GA and the western Upstate around daybreak, but even if they happen, amounts would only be a few hundredths at best. It is far likelier these locations will stay dry. Cloud cover may be extensive first thing in the morning, but will steadily clear out during the middle part of the day, allowing RH to once again mix down toward the mid-20-percents. How early the clouds move out may determine how much downward mixing of dry air occurs and how low the RH gets. Wind will be generally light and variable through much of Saturday over northeast GA, but should become light NW in the afternoon. Mixing will be a bit deeper Sunday, with RH a bit lower toward 20-25 percent, with wind remaining NW.
GSP WATCHES/WARNINGS/ADVISORIES. GA . None. NC . None. SC . None.
SYNOPSIS . MPR NEAR TERM . Wimberley/WJM SHORT TERM . PM LONG TERM . MPR AVIATION . Wimberley FIRE WEATHER . PM/Wimberley
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
|Stations||Dist||Age||Wind||Air Temp||Water Temp||Waves||Pressure||DewPt|
|CHDS1 - Strom Thurmond Dam, SC||46 mi||90 min||NW 6 G 8|
|LMFS1 - Lake Murray SC||74 mi||30 min||Calm G 1.9||53°F|
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports. Follow links for more data.
|Anderson, Anderson County Airport, SC||18 mi||54 min||NW 4||10.00 mi||Fair||53°F||28°F||38%||1015.7 hPa|
Link to 5 minute data for KAND
Wind History from AND (wind in knots)
|1 day ago|
|2 days ago|
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NOTE: This section has been updated as of 1/26/2021. If the image you are expecting is not showing, please let me know. You may use the EDIT function to update your location.
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