Issued by NWS Columbia, SC
Versions: 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --000 FXUS62 KCAE 212317 AFDCAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 617 PM EST SAT NOV 21 2009 .SYNOPSIS... A LOW PRESSURE SYSTEM IN THE NORTHWEST GULF OF MEXICO WILL MOVE SLOWLY NORTHEAST TO THE FLORIDA PANHANDLE TONIGHT...THEN REFORM ALONG THE CAROLINA COAST SUNDAY NIGHT. HIGH PRESSURE WILL WEDGE INTO THE CAROLINAS FROM THE NORTH. THIS PATTERN WILL BRING CLOUDS AND RAIN TO THE AREA THROUGH MONDAY. && .NEAR TERM /THROUGH TONIGHT/... CLOSED UPPER LOW OVER EAST TEXAS WILL DE-AMPLIFY OVERNIGHT AS IT MOVES NORTHEAST. SURFACE LOW OVER THE NORTHERN GULF OF MEXICO THIS AFTERNOON WILL SLOWLY MOVE EAST AS HIGH PRESSURE WEDGES INTO THE CAROLINAS FROM NORTH. SKIES EXPECTED TO BECOME CLOUDY TONIGHT AS ISENTROPIC LIFT BEGINS. RAIN SPREADING NORTH FROM THE GULF COAST STATES MAY REACH THE SAVANNAH RIVER AREA BY DAYBREAK SUNDAY. WENT WITH CONSENSUS LOWS...RANGING FROM THE MID 40S NORTH TO NEAR 50 SOUTH. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... MODELS FINALLY IN AGREEMENT WITH STRONG ISENTROPIC LIFT OVER THE AREA SUNDAY AFTERNOON INTO SUNDAY NIGHT. WEAKENING SHORT WAVE MOVING OUT OF TEXAS TONIGHT WILL CROSS GA INTO THE CAROLINAS SUNDAY NIGHT. LOW PRESSURE DEVELOPING ON AN INVERTED TROUGH OFF THE SC COAST. KEPT CATEGORICAL POPS FOR SUNDAY INTO SUNDAY NIGHT. RAINFALL AMOUNTS RANGING FROM ONE HALF INCH TO AROUND ONE INCH. THE SURFACE LOW WILL MOVE AWAY FROM THE COAST MONDAY WITH RAIN CHANCES DECREASING. KEPT CHANCE OF DRIZZLE IN FOR MONDAY NIGHT INTO TUESDAY. SINCE WEDGE PATTERN EXPECTED SUNDAY THROUGH TUESDAY...SHOULD SEE PLENTY OF CLOUDS. KEPT DAYTIME TEMPERATURES BELOW GUIDANCE. HIGHS IN THE LOW TO MID 50S (WHICH MAY BE ON THE HIGH SIDE). LITTLE DIURNAL CHANGE IN TEMPERATURES EXPECTED. LOWS IN THE MID TO UPPER 40S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MEDIUM RANGE MODELS DEPICT A SERIES OF MID/UPPER LEVEL LOWS MOVING ACROSS THE UPPER MIDWEST TO THE EASTERN GREAT LAKES AND SOUTHEASTERN CANADA TUESDAY NIGHT INTO SATURDAY. ALL IN ALL, SLIGHT UPPER RIDGING OVER THE SOUTHEAST PART OF THE COUNTRY TUESDAY IS REPLACED BY A LARGE UPPER TROUGH OVER THE EASTERN UNITED STATES WEDNESDAY THROUGH FRIDAY. UPPER TROUGH FINALLY MOVES OFF THE EAST COAST SATURDAY. SURFACE HIGH PRESSURE CENTERED OVER SOUTHEASTERN CANADA TUESDAY NIGHT RIDGING INTO THE AREA FROM THE NORTH. SURFACE LOW PRESSURE CROSSING THE GREAT LAKES REGION ON THANKSGIVING DAY WILL DRAG A COLD FRONT ACROSS THE AREA. MOISTURE APPEARS LIMITED SINCE THE BEST ISENTROPIC LIFT REMAINS SOUTH AND EAST OF THE FORECAST AREA. ANY CHANCE FOR RAIN (WHICH IS SLIGHT) LOOKS LIKE WEDNESDAY INTO THURSDAY MORNING. COOL HIGH PRESSURE BUILDS IN FOR FRIDAY AND SATURDAY. WILL KEEP THE EXTENDED FORECAST DRY. SEASONABLY MILD MAX TEMPERATURES WEDNESDAY AND THURSDAY COOL A FEW DEGREES BELOW NORMAL FOR FRIDAY AND SATURDAY. NIGHTTIME LOWS IN THE 40S MID-WEEK COOLING TO THE MID AND UPPER 30S BY LATE NEXT WEEK. && .AVIATION /00Z SUNDAY THROUGH FRIDAY/...-- Changed Discussion --HIGH PRESSURE OVER THE MID-ATLANTIC STATES WILL MOVE OFFSHORE AS A LOW PRESSURE SYSTEM OVER THE GULF OF MEXICO MOVES NORTHEAST. THIS LOW WILL TRACK OVER THE SE STATES ON SUNDAY BRINGING RAIN WITH MVFR/IFR CONDITIONS TO THE AREA. THE TAF PERIOD WILL START OUT VFR WITH MVFR CIGS DEVELOPING BY AROUND 12Z-14Z WITH SOME SPRINKLES POSSIBLE BY THEN. CONDITIONS BECOME IFR BY LATE IN THE TAF PERIOD AS PRECIPITATION SPREADS ACROSS THE REGION SUNDAY AFTERNOON. EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR IFR CONDITIONS WILL CONTINUE LATE SUNDAY INTO EARLY MONDAY AS THE LOW PRESSURE SYSTEM MOVES THROUGH THE AREA. CONDITIONS WILL IMPROVE TO VFR BY MONDAY AFTERNOON AS THE LOW MOVES OUT OF THE AREA.-- End Changed Discussion --&& .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
